mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-28 20:02:17 +00:00
![Greg Kroah-Hartman](/assets/img/avatar_default.png)
We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3450 lines
88 KiB
C
3450 lines
88 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* Base port operations for 8250/16550-type serial ports
|
|
*
|
|
* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
|
|
* Split from 8250_core.c, Copyright (C) 2001 Russell King.
|
|
*
|
|
* A note about mapbase / membase
|
|
*
|
|
* mapbase is the physical address of the IO port.
|
|
* membase is an 'ioremapped' cookie.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/init.h>
|
|
#include <linux/console.h>
|
|
#include <linux/gpio/consumer.h>
|
|
#include <linux/sysrq.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/ratelimit.h>
|
|
#include <linux/tty_flip.h>
|
|
#include <linux/serial.h>
|
|
#include <linux/serial_8250.h>
|
|
#include <linux/nmi.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/pm_runtime.h>
|
|
#include <linux/ktime.h>
|
|
|
|
#include <asm/io.h>
|
|
#include <asm/irq.h>
|
|
|
|
#include "8250.h"
|
|
|
|
/* Nuvoton NPCM timeout register */
|
|
#define UART_NPCM_TOR 7
|
|
#define UART_NPCM_TOIE BIT(7) /* Timeout Interrupt Enable */
|
|
|
|
/*
|
|
* Debugging.
|
|
*/
|
|
#if 0
|
|
#define DEBUG_AUTOCONF(fmt...) printk(fmt)
|
|
#else
|
|
#define DEBUG_AUTOCONF(fmt...) do { } while (0)
|
|
#endif
|
|
|
|
#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
|
|
|
|
/*
|
|
* Here we define the default xmit fifo size used for each type of UART.
|
|
*/
|
|
static const struct serial8250_config uart_config[] = {
|
|
[PORT_UNKNOWN] = {
|
|
.name = "unknown",
|
|
.fifo_size = 1,
|
|
.tx_loadsz = 1,
|
|
},
|
|
[PORT_8250] = {
|
|
.name = "8250",
|
|
.fifo_size = 1,
|
|
.tx_loadsz = 1,
|
|
},
|
|
[PORT_16450] = {
|
|
.name = "16450",
|
|
.fifo_size = 1,
|
|
.tx_loadsz = 1,
|
|
},
|
|
[PORT_16550] = {
|
|
.name = "16550",
|
|
.fifo_size = 1,
|
|
.tx_loadsz = 1,
|
|
},
|
|
[PORT_16550A] = {
|
|
.name = "16550A",
|
|
.fifo_size = 16,
|
|
.tx_loadsz = 16,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.rxtrig_bytes = {1, 4, 8, 14},
|
|
.flags = UART_CAP_FIFO,
|
|
},
|
|
[PORT_CIRRUS] = {
|
|
.name = "Cirrus",
|
|
.fifo_size = 1,
|
|
.tx_loadsz = 1,
|
|
},
|
|
[PORT_16650] = {
|
|
.name = "ST16650",
|
|
.fifo_size = 1,
|
|
.tx_loadsz = 1,
|
|
.flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
|
|
},
|
|
[PORT_16650V2] = {
|
|
.name = "ST16650V2",
|
|
.fifo_size = 32,
|
|
.tx_loadsz = 16,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
|
|
UART_FCR_T_TRIG_00,
|
|
.rxtrig_bytes = {8, 16, 24, 28},
|
|
.flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
|
|
},
|
|
[PORT_16750] = {
|
|
.name = "TI16750",
|
|
.fifo_size = 64,
|
|
.tx_loadsz = 64,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
|
|
UART_FCR7_64BYTE,
|
|
.rxtrig_bytes = {1, 16, 32, 56},
|
|
.flags = UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE,
|
|
},
|
|
[PORT_STARTECH] = {
|
|
.name = "Startech",
|
|
.fifo_size = 1,
|
|
.tx_loadsz = 1,
|
|
},
|
|
[PORT_16C950] = {
|
|
.name = "16C950/954",
|
|
.fifo_size = 128,
|
|
.tx_loadsz = 128,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01,
|
|
.rxtrig_bytes = {16, 32, 112, 120},
|
|
/* UART_CAP_EFR breaks billionon CF bluetooth card. */
|
|
.flags = UART_CAP_FIFO | UART_CAP_SLEEP,
|
|
},
|
|
[PORT_16654] = {
|
|
.name = "ST16654",
|
|
.fifo_size = 64,
|
|
.tx_loadsz = 32,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
|
|
UART_FCR_T_TRIG_10,
|
|
.rxtrig_bytes = {8, 16, 56, 60},
|
|
.flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
|
|
},
|
|
[PORT_16850] = {
|
|
.name = "XR16850",
|
|
.fifo_size = 128,
|
|
.tx_loadsz = 128,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
|
|
},
|
|
[PORT_RSA] = {
|
|
.name = "RSA",
|
|
.fifo_size = 2048,
|
|
.tx_loadsz = 2048,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11,
|
|
.flags = UART_CAP_FIFO,
|
|
},
|
|
[PORT_NS16550A] = {
|
|
.name = "NS16550A",
|
|
.fifo_size = 16,
|
|
.tx_loadsz = 16,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.flags = UART_CAP_FIFO | UART_NATSEMI,
|
|
},
|
|
[PORT_XSCALE] = {
|
|
.name = "XScale",
|
|
.fifo_size = 32,
|
|
.tx_loadsz = 32,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.flags = UART_CAP_FIFO | UART_CAP_UUE | UART_CAP_RTOIE,
|
|
},
|
|
[PORT_OCTEON] = {
|
|
.name = "OCTEON",
|
|
.fifo_size = 64,
|
|
.tx_loadsz = 64,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.flags = UART_CAP_FIFO,
|
|
},
|
|
[PORT_AR7] = {
|
|
.name = "AR7",
|
|
.fifo_size = 16,
|
|
.tx_loadsz = 16,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
|
|
.flags = UART_CAP_FIFO /* | UART_CAP_AFE */,
|
|
},
|
|
[PORT_U6_16550A] = {
|
|
.name = "U6_16550A",
|
|
.fifo_size = 64,
|
|
.tx_loadsz = 64,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.flags = UART_CAP_FIFO | UART_CAP_AFE,
|
|
},
|
|
[PORT_TEGRA] = {
|
|
.name = "Tegra",
|
|
.fifo_size = 32,
|
|
.tx_loadsz = 8,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
|
|
UART_FCR_T_TRIG_01,
|
|
.rxtrig_bytes = {1, 4, 8, 14},
|
|
.flags = UART_CAP_FIFO | UART_CAP_RTOIE,
|
|
},
|
|
[PORT_XR17D15X] = {
|
|
.name = "XR17D15X",
|
|
.fifo_size = 64,
|
|
.tx_loadsz = 64,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.flags = UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR |
|
|
UART_CAP_SLEEP,
|
|
},
|
|
[PORT_XR17V35X] = {
|
|
.name = "XR17V35X",
|
|
.fifo_size = 256,
|
|
.tx_loadsz = 256,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11 |
|
|
UART_FCR_T_TRIG_11,
|
|
.flags = UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR |
|
|
UART_CAP_SLEEP,
|
|
},
|
|
[PORT_LPC3220] = {
|
|
.name = "LPC3220",
|
|
.fifo_size = 64,
|
|
.tx_loadsz = 32,
|
|
.fcr = UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO |
|
|
UART_FCR_R_TRIG_00 | UART_FCR_T_TRIG_00,
|
|
.flags = UART_CAP_FIFO,
|
|
},
|
|
[PORT_BRCM_TRUMANAGE] = {
|
|
.name = "TruManage",
|
|
.fifo_size = 1,
|
|
.tx_loadsz = 1024,
|
|
.flags = UART_CAP_HFIFO,
|
|
},
|
|
[PORT_8250_CIR] = {
|
|
.name = "CIR port"
|
|
},
|
|
[PORT_ALTR_16550_F32] = {
|
|
.name = "Altera 16550 FIFO32",
|
|
.fifo_size = 32,
|
|
.tx_loadsz = 32,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.rxtrig_bytes = {1, 8, 16, 30},
|
|
.flags = UART_CAP_FIFO | UART_CAP_AFE,
|
|
},
|
|
[PORT_ALTR_16550_F64] = {
|
|
.name = "Altera 16550 FIFO64",
|
|
.fifo_size = 64,
|
|
.tx_loadsz = 64,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.rxtrig_bytes = {1, 16, 32, 62},
|
|
.flags = UART_CAP_FIFO | UART_CAP_AFE,
|
|
},
|
|
[PORT_ALTR_16550_F128] = {
|
|
.name = "Altera 16550 FIFO128",
|
|
.fifo_size = 128,
|
|
.tx_loadsz = 128,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.rxtrig_bytes = {1, 32, 64, 126},
|
|
.flags = UART_CAP_FIFO | UART_CAP_AFE,
|
|
},
|
|
/*
|
|
* tx_loadsz is set to 63-bytes instead of 64-bytes to implement
|
|
* workaround of errata A-008006 which states that tx_loadsz should
|
|
* be configured less than Maximum supported fifo bytes.
|
|
*/
|
|
[PORT_16550A_FSL64] = {
|
|
.name = "16550A_FSL64",
|
|
.fifo_size = 64,
|
|
.tx_loadsz = 63,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
|
|
UART_FCR7_64BYTE,
|
|
.flags = UART_CAP_FIFO,
|
|
},
|
|
[PORT_RT2880] = {
|
|
.name = "Palmchip BK-3103",
|
|
.fifo_size = 16,
|
|
.tx_loadsz = 16,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.rxtrig_bytes = {1, 4, 8, 14},
|
|
.flags = UART_CAP_FIFO,
|
|
},
|
|
[PORT_DA830] = {
|
|
.name = "TI DA8xx/66AK2x",
|
|
.fifo_size = 16,
|
|
.tx_loadsz = 16,
|
|
.fcr = UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO |
|
|
UART_FCR_R_TRIG_10,
|
|
.rxtrig_bytes = {1, 4, 8, 14},
|
|
.flags = UART_CAP_FIFO | UART_CAP_AFE,
|
|
},
|
|
[PORT_MTK_BTIF] = {
|
|
.name = "MediaTek BTIF",
|
|
.fifo_size = 16,
|
|
.tx_loadsz = 16,
|
|
.fcr = UART_FCR_ENABLE_FIFO |
|
|
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
|
|
.flags = UART_CAP_FIFO,
|
|
},
|
|
[PORT_NPCM] = {
|
|
.name = "Nuvoton 16550",
|
|
.fifo_size = 16,
|
|
.tx_loadsz = 16,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
|
|
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
|
|
.rxtrig_bytes = {1, 4, 8, 14},
|
|
.flags = UART_CAP_FIFO,
|
|
},
|
|
[PORT_SUNIX] = {
|
|
.name = "Sunix",
|
|
.fifo_size = 128,
|
|
.tx_loadsz = 128,
|
|
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
|
.rxtrig_bytes = {1, 32, 64, 112},
|
|
.flags = UART_CAP_FIFO | UART_CAP_SLEEP,
|
|
},
|
|
};
|
|
|
|
/* Uart divisor latch read */
|
|
static int default_serial_dl_read(struct uart_8250_port *up)
|
|
{
|
|
/* Assign these in pieces to truncate any bits above 7. */
|
|
unsigned char dll = serial_in(up, UART_DLL);
|
|
unsigned char dlm = serial_in(up, UART_DLM);
|
|
|
|
return dll | dlm << 8;
|
|
}
|
|
|
|
/* Uart divisor latch write */
|
|
static void default_serial_dl_write(struct uart_8250_port *up, int value)
|
|
{
|
|
serial_out(up, UART_DLL, value & 0xff);
|
|
serial_out(up, UART_DLM, value >> 8 & 0xff);
|
|
}
|
|
|
|
#ifdef CONFIG_SERIAL_8250_RT288X
|
|
|
|
/* Au1x00/RT288x UART hardware has a weird register layout */
|
|
static const s8 au_io_in_map[8] = {
|
|
0, /* UART_RX */
|
|
2, /* UART_IER */
|
|
3, /* UART_IIR */
|
|
5, /* UART_LCR */
|
|
6, /* UART_MCR */
|
|
7, /* UART_LSR */
|
|
8, /* UART_MSR */
|
|
-1, /* UART_SCR (unmapped) */
|
|
};
|
|
|
|
static const s8 au_io_out_map[8] = {
|
|
1, /* UART_TX */
|
|
2, /* UART_IER */
|
|
4, /* UART_FCR */
|
|
5, /* UART_LCR */
|
|
6, /* UART_MCR */
|
|
-1, /* UART_LSR (unmapped) */
|
|
-1, /* UART_MSR (unmapped) */
|
|
-1, /* UART_SCR (unmapped) */
|
|
};
|
|
|
|
unsigned int au_serial_in(struct uart_port *p, int offset)
|
|
{
|
|
if (offset >= ARRAY_SIZE(au_io_in_map))
|
|
return UINT_MAX;
|
|
offset = au_io_in_map[offset];
|
|
if (offset < 0)
|
|
return UINT_MAX;
|
|
return __raw_readl(p->membase + (offset << p->regshift));
|
|
}
|
|
|
|
void au_serial_out(struct uart_port *p, int offset, int value)
|
|
{
|
|
if (offset >= ARRAY_SIZE(au_io_out_map))
|
|
return;
|
|
offset = au_io_out_map[offset];
|
|
if (offset < 0)
|
|
return;
|
|
__raw_writel(value, p->membase + (offset << p->regshift));
|
|
}
|
|
|
|
/* Au1x00 haven't got a standard divisor latch */
|
|
static int au_serial_dl_read(struct uart_8250_port *up)
|
|
{
|
|
return __raw_readl(up->port.membase + 0x28);
|
|
}
|
|
|
|
static void au_serial_dl_write(struct uart_8250_port *up, int value)
|
|
{
|
|
__raw_writel(value, up->port.membase + 0x28);
|
|
}
|
|
|
|
#endif
|
|
|
|
static unsigned int hub6_serial_in(struct uart_port *p, int offset)
|
|
{
|
|
offset = offset << p->regshift;
|
|
outb(p->hub6 - 1 + offset, p->iobase);
|
|
return inb(p->iobase + 1);
|
|
}
|
|
|
|
static void hub6_serial_out(struct uart_port *p, int offset, int value)
|
|
{
|
|
offset = offset << p->regshift;
|
|
outb(p->hub6 - 1 + offset, p->iobase);
|
|
outb(value, p->iobase + 1);
|
|
}
|
|
|
|
static unsigned int mem_serial_in(struct uart_port *p, int offset)
|
|
{
|
|
offset = offset << p->regshift;
|
|
return readb(p->membase + offset);
|
|
}
|
|
|
|
static void mem_serial_out(struct uart_port *p, int offset, int value)
|
|
{
|
|
offset = offset << p->regshift;
|
|
writeb(value, p->membase + offset);
|
|
}
|
|
|
|
static void mem16_serial_out(struct uart_port *p, int offset, int value)
|
|
{
|
|
offset = offset << p->regshift;
|
|
writew(value, p->membase + offset);
|
|
}
|
|
|
|
static unsigned int mem16_serial_in(struct uart_port *p, int offset)
|
|
{
|
|
offset = offset << p->regshift;
|
|
return readw(p->membase + offset);
|
|
}
|
|
|
|
static void mem32_serial_out(struct uart_port *p, int offset, int value)
|
|
{
|
|
offset = offset << p->regshift;
|
|
writel(value, p->membase + offset);
|
|
}
|
|
|
|
static unsigned int mem32_serial_in(struct uart_port *p, int offset)
|
|
{
|
|
offset = offset << p->regshift;
|
|
return readl(p->membase + offset);
|
|
}
|
|
|
|
static void mem32be_serial_out(struct uart_port *p, int offset, int value)
|
|
{
|
|
offset = offset << p->regshift;
|
|
iowrite32be(value, p->membase + offset);
|
|
}
|
|
|
|
static unsigned int mem32be_serial_in(struct uart_port *p, int offset)
|
|
{
|
|
offset = offset << p->regshift;
|
|
return ioread32be(p->membase + offset);
|
|
}
|
|
|
|
static unsigned int io_serial_in(struct uart_port *p, int offset)
|
|
{
|
|
offset = offset << p->regshift;
|
|
return inb(p->iobase + offset);
|
|
}
|
|
|
|
static void io_serial_out(struct uart_port *p, int offset, int value)
|
|
{
|
|
offset = offset << p->regshift;
|
|
outb(value, p->iobase + offset);
|
|
}
|
|
|
|
static int serial8250_default_handle_irq(struct uart_port *port);
|
|
|
|
static void set_io_from_upio(struct uart_port *p)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(p);
|
|
|
|
up->dl_read = default_serial_dl_read;
|
|
up->dl_write = default_serial_dl_write;
|
|
|
|
switch (p->iotype) {
|
|
case UPIO_HUB6:
|
|
p->serial_in = hub6_serial_in;
|
|
p->serial_out = hub6_serial_out;
|
|
break;
|
|
|
|
case UPIO_MEM:
|
|
p->serial_in = mem_serial_in;
|
|
p->serial_out = mem_serial_out;
|
|
break;
|
|
|
|
case UPIO_MEM16:
|
|
p->serial_in = mem16_serial_in;
|
|
p->serial_out = mem16_serial_out;
|
|
break;
|
|
|
|
case UPIO_MEM32:
|
|
p->serial_in = mem32_serial_in;
|
|
p->serial_out = mem32_serial_out;
|
|
break;
|
|
|
|
case UPIO_MEM32BE:
|
|
p->serial_in = mem32be_serial_in;
|
|
p->serial_out = mem32be_serial_out;
|
|
break;
|
|
|
|
#ifdef CONFIG_SERIAL_8250_RT288X
|
|
case UPIO_AU:
|
|
p->serial_in = au_serial_in;
|
|
p->serial_out = au_serial_out;
|
|
up->dl_read = au_serial_dl_read;
|
|
up->dl_write = au_serial_dl_write;
|
|
break;
|
|
#endif
|
|
|
|
default:
|
|
p->serial_in = io_serial_in;
|
|
p->serial_out = io_serial_out;
|
|
break;
|
|
}
|
|
/* Remember loaded iotype */
|
|
up->cur_iotype = p->iotype;
|
|
p->handle_irq = serial8250_default_handle_irq;
|
|
}
|
|
|
|
static void
|
|
serial_port_out_sync(struct uart_port *p, int offset, int value)
|
|
{
|
|
switch (p->iotype) {
|
|
case UPIO_MEM:
|
|
case UPIO_MEM16:
|
|
case UPIO_MEM32:
|
|
case UPIO_MEM32BE:
|
|
case UPIO_AU:
|
|
p->serial_out(p, offset, value);
|
|
p->serial_in(p, UART_LCR); /* safe, no side-effects */
|
|
break;
|
|
default:
|
|
p->serial_out(p, offset, value);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* For the 16C950
|
|
*/
|
|
static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
|
|
{
|
|
serial_out(up, UART_SCR, offset);
|
|
serial_out(up, UART_ICR, value);
|
|
}
|
|
|
|
static unsigned int serial_icr_read(struct uart_8250_port *up, int offset)
|
|
{
|
|
unsigned int value;
|
|
|
|
serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
|
|
serial_out(up, UART_SCR, offset);
|
|
value = serial_in(up, UART_ICR);
|
|
serial_icr_write(up, UART_ACR, up->acr);
|
|
|
|
return value;
|
|
}
|
|
|
|
/*
|
|
* FIFO support.
|
|
*/
|
|
static void serial8250_clear_fifos(struct uart_8250_port *p)
|
|
{
|
|
if (p->capabilities & UART_CAP_FIFO) {
|
|
serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO);
|
|
serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO |
|
|
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
|
|
serial_out(p, UART_FCR, 0);
|
|
}
|
|
}
|
|
|
|
static enum hrtimer_restart serial8250_em485_handle_start_tx(struct hrtimer *t);
|
|
static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t);
|
|
|
|
void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p)
|
|
{
|
|
serial8250_clear_fifos(p);
|
|
serial_out(p, UART_FCR, p->fcr);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos);
|
|
|
|
void serial8250_rpm_get(struct uart_8250_port *p)
|
|
{
|
|
if (!(p->capabilities & UART_CAP_RPM))
|
|
return;
|
|
pm_runtime_get_sync(p->port.dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_rpm_get);
|
|
|
|
void serial8250_rpm_put(struct uart_8250_port *p)
|
|
{
|
|
if (!(p->capabilities & UART_CAP_RPM))
|
|
return;
|
|
pm_runtime_mark_last_busy(p->port.dev);
|
|
pm_runtime_put_autosuspend(p->port.dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_rpm_put);
|
|
|
|
/**
|
|
* serial8250_em485_init() - put uart_8250_port into rs485 emulating
|
|
* @p: uart_8250_port port instance
|
|
*
|
|
* The function is used to start rs485 software emulating on the
|
|
* &struct uart_8250_port* @p. Namely, RTS is switched before/after
|
|
* transmission. The function is idempotent, so it is safe to call it
|
|
* multiple times.
|
|
*
|
|
* The caller MUST enable interrupt on empty shift register before
|
|
* calling serial8250_em485_init(). This interrupt is not a part of
|
|
* 8250 standard, but implementation defined.
|
|
*
|
|
* The function is supposed to be called from .rs485_config callback
|
|
* or from any other callback protected with p->port.lock spinlock.
|
|
*
|
|
* See also serial8250_em485_destroy()
|
|
*
|
|
* Return 0 - success, -errno - otherwise
|
|
*/
|
|
static int serial8250_em485_init(struct uart_8250_port *p)
|
|
{
|
|
if (p->em485)
|
|
return 0;
|
|
|
|
p->em485 = kmalloc(sizeof(struct uart_8250_em485), GFP_ATOMIC);
|
|
if (!p->em485)
|
|
return -ENOMEM;
|
|
|
|
hrtimer_init(&p->em485->stop_tx_timer, CLOCK_MONOTONIC,
|
|
HRTIMER_MODE_REL);
|
|
hrtimer_init(&p->em485->start_tx_timer, CLOCK_MONOTONIC,
|
|
HRTIMER_MODE_REL);
|
|
p->em485->stop_tx_timer.function = &serial8250_em485_handle_stop_tx;
|
|
p->em485->start_tx_timer.function = &serial8250_em485_handle_start_tx;
|
|
p->em485->port = p;
|
|
p->em485->active_timer = NULL;
|
|
p->em485->tx_stopped = true;
|
|
|
|
p->rs485_stop_tx(p);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* serial8250_em485_destroy() - put uart_8250_port into normal state
|
|
* @p: uart_8250_port port instance
|
|
*
|
|
* The function is used to stop rs485 software emulating on the
|
|
* &struct uart_8250_port* @p. The function is idempotent, so it is safe to
|
|
* call it multiple times.
|
|
*
|
|
* The function is supposed to be called from .rs485_config callback
|
|
* or from any other callback protected with p->port.lock spinlock.
|
|
*
|
|
* See also serial8250_em485_init()
|
|
*/
|
|
void serial8250_em485_destroy(struct uart_8250_port *p)
|
|
{
|
|
if (!p->em485)
|
|
return;
|
|
|
|
hrtimer_cancel(&p->em485->start_tx_timer);
|
|
hrtimer_cancel(&p->em485->stop_tx_timer);
|
|
|
|
kfree(p->em485);
|
|
p->em485 = NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_em485_destroy);
|
|
|
|
/**
|
|
* serial8250_em485_config() - generic ->rs485_config() callback
|
|
* @port: uart port
|
|
* @rs485: rs485 settings
|
|
*
|
|
* Generic callback usable by 8250 uart drivers to activate rs485 settings
|
|
* if the uart is incapable of driving RTS as a Transmit Enable signal in
|
|
* hardware, relying on software emulation instead.
|
|
*/
|
|
int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
/* pick sane settings if the user hasn't */
|
|
if (!!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
|
|
!!(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
|
|
rs485->flags |= SER_RS485_RTS_ON_SEND;
|
|
rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
|
|
}
|
|
|
|
/* clamp the delays to [0, 100ms] */
|
|
rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
|
|
rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);
|
|
|
|
memset(rs485->padding, 0, sizeof(rs485->padding));
|
|
port->rs485 = *rs485;
|
|
|
|
gpiod_set_value(port->rs485_term_gpio,
|
|
rs485->flags & SER_RS485_TERMINATE_BUS);
|
|
|
|
/*
|
|
* Both serial8250_em485_init() and serial8250_em485_destroy()
|
|
* are idempotent.
|
|
*/
|
|
if (rs485->flags & SER_RS485_ENABLED) {
|
|
int ret = serial8250_em485_init(up);
|
|
|
|
if (ret) {
|
|
rs485->flags &= ~SER_RS485_ENABLED;
|
|
port->rs485.flags &= ~SER_RS485_ENABLED;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
serial8250_em485_destroy(up);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_em485_config);
|
|
|
|
/*
|
|
* These two wrappers ensure that enable_runtime_pm_tx() can be called more than
|
|
* once and disable_runtime_pm_tx() will still disable RPM because the fifo is
|
|
* empty and the HW can idle again.
|
|
*/
|
|
void serial8250_rpm_get_tx(struct uart_8250_port *p)
|
|
{
|
|
unsigned char rpm_active;
|
|
|
|
if (!(p->capabilities & UART_CAP_RPM))
|
|
return;
|
|
|
|
rpm_active = xchg(&p->rpm_tx_active, 1);
|
|
if (rpm_active)
|
|
return;
|
|
pm_runtime_get_sync(p->port.dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_rpm_get_tx);
|
|
|
|
void serial8250_rpm_put_tx(struct uart_8250_port *p)
|
|
{
|
|
unsigned char rpm_active;
|
|
|
|
if (!(p->capabilities & UART_CAP_RPM))
|
|
return;
|
|
|
|
rpm_active = xchg(&p->rpm_tx_active, 0);
|
|
if (!rpm_active)
|
|
return;
|
|
pm_runtime_mark_last_busy(p->port.dev);
|
|
pm_runtime_put_autosuspend(p->port.dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_rpm_put_tx);
|
|
|
|
/*
|
|
* IER sleep support. UARTs which have EFRs need the "extended
|
|
* capability" bit enabled. Note that on XR16C850s, we need to
|
|
* reset LCR to write to IER.
|
|
*/
|
|
static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
|
|
{
|
|
unsigned char lcr = 0, efr = 0;
|
|
|
|
serial8250_rpm_get(p);
|
|
|
|
if (p->capabilities & UART_CAP_SLEEP) {
|
|
if (p->capabilities & UART_CAP_EFR) {
|
|
lcr = serial_in(p, UART_LCR);
|
|
efr = serial_in(p, UART_EFR);
|
|
serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
|
|
serial_out(p, UART_EFR, UART_EFR_ECB);
|
|
serial_out(p, UART_LCR, 0);
|
|
}
|
|
serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
|
|
if (p->capabilities & UART_CAP_EFR) {
|
|
serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
|
|
serial_out(p, UART_EFR, efr);
|
|
serial_out(p, UART_LCR, lcr);
|
|
}
|
|
}
|
|
|
|
serial8250_rpm_put(p);
|
|
}
|
|
|
|
#ifdef CONFIG_SERIAL_8250_RSA
|
|
/*
|
|
* Attempts to turn on the RSA FIFO. Returns zero on failure.
|
|
* We set the port uart clock rate if we succeed.
|
|
*/
|
|
static int __enable_rsa(struct uart_8250_port *up)
|
|
{
|
|
unsigned char mode;
|
|
int result;
|
|
|
|
mode = serial_in(up, UART_RSA_MSR);
|
|
result = mode & UART_RSA_MSR_FIFO;
|
|
|
|
if (!result) {
|
|
serial_out(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
|
|
mode = serial_in(up, UART_RSA_MSR);
|
|
result = mode & UART_RSA_MSR_FIFO;
|
|
}
|
|
|
|
if (result)
|
|
up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
|
|
|
|
return result;
|
|
}
|
|
|
|
static void enable_rsa(struct uart_8250_port *up)
|
|
{
|
|
if (up->port.type == PORT_RSA) {
|
|
if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
|
|
spin_lock_irq(&up->port.lock);
|
|
__enable_rsa(up);
|
|
spin_unlock_irq(&up->port.lock);
|
|
}
|
|
if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
|
|
serial_out(up, UART_RSA_FRR, 0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Attempts to turn off the RSA FIFO. Returns zero on failure.
|
|
* It is unknown why interrupts were disabled in here. However,
|
|
* the caller is expected to preserve this behaviour by grabbing
|
|
* the spinlock before calling this function.
|
|
*/
|
|
static void disable_rsa(struct uart_8250_port *up)
|
|
{
|
|
unsigned char mode;
|
|
int result;
|
|
|
|
if (up->port.type == PORT_RSA &&
|
|
up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
|
|
spin_lock_irq(&up->port.lock);
|
|
|
|
mode = serial_in(up, UART_RSA_MSR);
|
|
result = !(mode & UART_RSA_MSR_FIFO);
|
|
|
|
if (!result) {
|
|
serial_out(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
|
|
mode = serial_in(up, UART_RSA_MSR);
|
|
result = !(mode & UART_RSA_MSR_FIFO);
|
|
}
|
|
|
|
if (result)
|
|
up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
|
|
spin_unlock_irq(&up->port.lock);
|
|
}
|
|
}
|
|
#endif /* CONFIG_SERIAL_8250_RSA */
|
|
|
|
/*
|
|
* This is a quickie test to see how big the FIFO is.
|
|
* It doesn't work at all the time, more's the pity.
|
|
*/
|
|
static int size_fifo(struct uart_8250_port *up)
|
|
{
|
|
unsigned char old_fcr, old_mcr, old_lcr;
|
|
unsigned short old_dl;
|
|
int count;
|
|
|
|
old_lcr = serial_in(up, UART_LCR);
|
|
serial_out(up, UART_LCR, 0);
|
|
old_fcr = serial_in(up, UART_FCR);
|
|
old_mcr = serial8250_in_MCR(up);
|
|
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
|
|
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
|
|
serial8250_out_MCR(up, UART_MCR_LOOP);
|
|
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
|
|
old_dl = serial_dl_read(up);
|
|
serial_dl_write(up, 0x0001);
|
|
serial_out(up, UART_LCR, 0x03);
|
|
for (count = 0; count < 256; count++)
|
|
serial_out(up, UART_TX, count);
|
|
mdelay(20);/* FIXME - schedule_timeout */
|
|
for (count = 0; (serial_in(up, UART_LSR) & UART_LSR_DR) &&
|
|
(count < 256); count++)
|
|
serial_in(up, UART_RX);
|
|
serial_out(up, UART_FCR, old_fcr);
|
|
serial8250_out_MCR(up, old_mcr);
|
|
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
|
|
serial_dl_write(up, old_dl);
|
|
serial_out(up, UART_LCR, old_lcr);
|
|
|
|
return count;
|
|
}
|
|
|
|
/*
|
|
* Read UART ID using the divisor method - set DLL and DLM to zero
|
|
* and the revision will be in DLL and device type in DLM. We
|
|
* preserve the device state across this.
|
|
*/
|
|
static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
|
|
{
|
|
unsigned char old_lcr;
|
|
unsigned int id, old_dl;
|
|
|
|
old_lcr = serial_in(p, UART_LCR);
|
|
serial_out(p, UART_LCR, UART_LCR_CONF_MODE_A);
|
|
old_dl = serial_dl_read(p);
|
|
serial_dl_write(p, 0);
|
|
id = serial_dl_read(p);
|
|
serial_dl_write(p, old_dl);
|
|
|
|
serial_out(p, UART_LCR, old_lcr);
|
|
|
|
return id;
|
|
}
|
|
|
|
/*
|
|
* This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
|
|
* When this function is called we know it is at least a StarTech
|
|
* 16650 V2, but it might be one of several StarTech UARTs, or one of
|
|
* its clones. (We treat the broken original StarTech 16650 V1 as a
|
|
* 16550, and why not? Startech doesn't seem to even acknowledge its
|
|
* existence.)
|
|
*
|
|
* What evil have men's minds wrought...
|
|
*/
|
|
static void autoconfig_has_efr(struct uart_8250_port *up)
|
|
{
|
|
unsigned int id1, id2, id3, rev;
|
|
|
|
/*
|
|
* Everything with an EFR has SLEEP
|
|
*/
|
|
up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
|
|
|
|
/*
|
|
* First we check to see if it's an Oxford Semiconductor UART.
|
|
*
|
|
* If we have to do this here because some non-National
|
|
* Semiconductor clone chips lock up if you try writing to the
|
|
* LSR register (which serial_icr_read does)
|
|
*/
|
|
|
|
/*
|
|
* Check for Oxford Semiconductor 16C950.
|
|
*
|
|
* EFR [4] must be set else this test fails.
|
|
*
|
|
* This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca)
|
|
* claims that it's needed for 952 dual UART's (which are not
|
|
* recommended for new designs).
|
|
*/
|
|
up->acr = 0;
|
|
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
|
|
serial_out(up, UART_EFR, UART_EFR_ECB);
|
|
serial_out(up, UART_LCR, 0x00);
|
|
id1 = serial_icr_read(up, UART_ID1);
|
|
id2 = serial_icr_read(up, UART_ID2);
|
|
id3 = serial_icr_read(up, UART_ID3);
|
|
rev = serial_icr_read(up, UART_REV);
|
|
|
|
DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
|
|
|
|
if (id1 == 0x16 && id2 == 0xC9 &&
|
|
(id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
|
|
up->port.type = PORT_16C950;
|
|
|
|
/*
|
|
* Enable work around for the Oxford Semiconductor 952 rev B
|
|
* chip which causes it to seriously miscalculate baud rates
|
|
* when DLL is 0.
|
|
*/
|
|
if (id3 == 0x52 && rev == 0x01)
|
|
up->bugs |= UART_BUG_QUOT;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* We check for a XR16C850 by setting DLL and DLM to 0, and then
|
|
* reading back DLL and DLM. The chip type depends on the DLM
|
|
* value read back:
|
|
* 0x10 - XR16C850 and the DLL contains the chip revision.
|
|
* 0x12 - XR16C2850.
|
|
* 0x14 - XR16C854.
|
|
*/
|
|
id1 = autoconfig_read_divisor_id(up);
|
|
DEBUG_AUTOCONF("850id=%04x ", id1);
|
|
|
|
id2 = id1 >> 8;
|
|
if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
|
|
up->port.type = PORT_16850;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* It wasn't an XR16C850.
|
|
*
|
|
* We distinguish between the '654 and the '650 by counting
|
|
* how many bytes are in the FIFO. I'm using this for now,
|
|
* since that's the technique that was sent to me in the
|
|
* serial driver update, but I'm not convinced this works.
|
|
* I've had problems doing this in the past. -TYT
|
|
*/
|
|
if (size_fifo(up) == 64)
|
|
up->port.type = PORT_16654;
|
|
else
|
|
up->port.type = PORT_16650V2;
|
|
}
|
|
|
|
/*
|
|
* We detected a chip without a FIFO. Only two fall into
|
|
* this category - the original 8250 and the 16450. The
|
|
* 16450 has a scratch register (accessible with LCR=0)
|
|
*/
|
|
static void autoconfig_8250(struct uart_8250_port *up)
|
|
{
|
|
unsigned char scratch, status1, status2;
|
|
|
|
up->port.type = PORT_8250;
|
|
|
|
scratch = serial_in(up, UART_SCR);
|
|
serial_out(up, UART_SCR, 0xa5);
|
|
status1 = serial_in(up, UART_SCR);
|
|
serial_out(up, UART_SCR, 0x5a);
|
|
status2 = serial_in(up, UART_SCR);
|
|
serial_out(up, UART_SCR, scratch);
|
|
|
|
if (status1 == 0xa5 && status2 == 0x5a)
|
|
up->port.type = PORT_16450;
|
|
}
|
|
|
|
static int broken_efr(struct uart_8250_port *up)
|
|
{
|
|
/*
|
|
* Exar ST16C2550 "A2" devices incorrectly detect as
|
|
* having an EFR, and report an ID of 0x0201. See
|
|
* http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/4812.html
|
|
*/
|
|
if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* We know that the chip has FIFOs. Does it have an EFR? The
|
|
* EFR is located in the same register position as the IIR and
|
|
* we know the top two bits of the IIR are currently set. The
|
|
* EFR should contain zero. Try to read the EFR.
|
|
*/
|
|
static void autoconfig_16550a(struct uart_8250_port *up)
|
|
{
|
|
unsigned char status1, status2;
|
|
unsigned int iersave;
|
|
|
|
up->port.type = PORT_16550A;
|
|
up->capabilities |= UART_CAP_FIFO;
|
|
|
|
if (!IS_ENABLED(CONFIG_SERIAL_8250_16550A_VARIANTS))
|
|
return;
|
|
|
|
/*
|
|
* Check for presence of the EFR when DLAB is set.
|
|
* Only ST16C650V1 UARTs pass this test.
|
|
*/
|
|
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
|
|
if (serial_in(up, UART_EFR) == 0) {
|
|
serial_out(up, UART_EFR, 0xA8);
|
|
if (serial_in(up, UART_EFR) != 0) {
|
|
DEBUG_AUTOCONF("EFRv1 ");
|
|
up->port.type = PORT_16650;
|
|
up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
|
|
} else {
|
|
serial_out(up, UART_LCR, 0);
|
|
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
|
|
UART_FCR7_64BYTE);
|
|
status1 = serial_in(up, UART_IIR) >> 5;
|
|
serial_out(up, UART_FCR, 0);
|
|
serial_out(up, UART_LCR, 0);
|
|
|
|
if (status1 == 7)
|
|
up->port.type = PORT_16550A_FSL64;
|
|
else
|
|
DEBUG_AUTOCONF("Motorola 8xxx DUART ");
|
|
}
|
|
serial_out(up, UART_EFR, 0);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Maybe it requires 0xbf to be written to the LCR.
|
|
* (other ST16C650V2 UARTs, TI16C752A, etc)
|
|
*/
|
|
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
|
|
if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
|
|
DEBUG_AUTOCONF("EFRv2 ");
|
|
autoconfig_has_efr(up);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Check for a National Semiconductor SuperIO chip.
|
|
* Attempt to switch to bank 2, read the value of the LOOP bit
|
|
* from EXCR1. Switch back to bank 0, change it in MCR. Then
|
|
* switch back to bank 2, read it from EXCR1 again and check
|
|
* it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
|
|
*/
|
|
serial_out(up, UART_LCR, 0);
|
|
status1 = serial8250_in_MCR(up);
|
|
serial_out(up, UART_LCR, 0xE0);
|
|
status2 = serial_in(up, 0x02); /* EXCR1 */
|
|
|
|
if (!((status2 ^ status1) & UART_MCR_LOOP)) {
|
|
serial_out(up, UART_LCR, 0);
|
|
serial8250_out_MCR(up, status1 ^ UART_MCR_LOOP);
|
|
serial_out(up, UART_LCR, 0xE0);
|
|
status2 = serial_in(up, 0x02); /* EXCR1 */
|
|
serial_out(up, UART_LCR, 0);
|
|
serial8250_out_MCR(up, status1);
|
|
|
|
if ((status2 ^ status1) & UART_MCR_LOOP) {
|
|
unsigned short quot;
|
|
|
|
serial_out(up, UART_LCR, 0xE0);
|
|
|
|
quot = serial_dl_read(up);
|
|
quot <<= 3;
|
|
|
|
if (ns16550a_goto_highspeed(up))
|
|
serial_dl_write(up, quot);
|
|
|
|
serial_out(up, UART_LCR, 0);
|
|
|
|
up->port.uartclk = 921600*16;
|
|
up->port.type = PORT_NS16550A;
|
|
up->capabilities |= UART_NATSEMI;
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* No EFR. Try to detect a TI16750, which only sets bit 5 of
|
|
* the IIR when 64 byte FIFO mode is enabled when DLAB is set.
|
|
* Try setting it with and without DLAB set. Cheap clones
|
|
* set bit 5 without DLAB set.
|
|
*/
|
|
serial_out(up, UART_LCR, 0);
|
|
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
|
|
status1 = serial_in(up, UART_IIR) >> 5;
|
|
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
|
|
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
|
|
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
|
|
status2 = serial_in(up, UART_IIR) >> 5;
|
|
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
|
|
serial_out(up, UART_LCR, 0);
|
|
|
|
DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
|
|
|
|
if (status1 == 6 && status2 == 7) {
|
|
up->port.type = PORT_16750;
|
|
up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Try writing and reading the UART_IER_UUE bit (b6).
|
|
* If it works, this is probably one of the Xscale platform's
|
|
* internal UARTs.
|
|
* We're going to explicitly set the UUE bit to 0 before
|
|
* trying to write and read a 1 just to make sure it's not
|
|
* already a 1 and maybe locked there before we even start start.
|
|
*/
|
|
iersave = serial_in(up, UART_IER);
|
|
serial_out(up, UART_IER, iersave & ~UART_IER_UUE);
|
|
if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
|
|
/*
|
|
* OK it's in a known zero state, try writing and reading
|
|
* without disturbing the current state of the other bits.
|
|
*/
|
|
serial_out(up, UART_IER, iersave | UART_IER_UUE);
|
|
if (serial_in(up, UART_IER) & UART_IER_UUE) {
|
|
/*
|
|
* It's an Xscale.
|
|
* We'll leave the UART_IER_UUE bit set to 1 (enabled).
|
|
*/
|
|
DEBUG_AUTOCONF("Xscale ");
|
|
up->port.type = PORT_XSCALE;
|
|
up->capabilities |= UART_CAP_UUE | UART_CAP_RTOIE;
|
|
return;
|
|
}
|
|
} else {
|
|
/*
|
|
* If we got here we couldn't force the IER_UUE bit to 0.
|
|
* Log it and continue.
|
|
*/
|
|
DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
|
|
}
|
|
serial_out(up, UART_IER, iersave);
|
|
|
|
/*
|
|
* We distinguish between 16550A and U6 16550A by counting
|
|
* how many bytes are in the FIFO.
|
|
*/
|
|
if (up->port.type == PORT_16550A && size_fifo(up) == 64) {
|
|
up->port.type = PORT_U6_16550A;
|
|
up->capabilities |= UART_CAP_AFE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This routine is called by rs_init() to initialize a specific serial
|
|
* port. It determines what type of UART chip this serial port is
|
|
* using: 8250, 16450, 16550, 16550A. The important question is
|
|
* whether or not this UART is a 16550A or not, since this will
|
|
* determine whether or not we can use its FIFO features or not.
|
|
*/
|
|
static void autoconfig(struct uart_8250_port *up)
|
|
{
|
|
unsigned char status1, scratch, scratch2, scratch3;
|
|
unsigned char save_lcr, save_mcr;
|
|
struct uart_port *port = &up->port;
|
|
unsigned long flags;
|
|
unsigned int old_capabilities;
|
|
|
|
if (!port->iobase && !port->mapbase && !port->membase)
|
|
return;
|
|
|
|
DEBUG_AUTOCONF("%s: autoconf (0x%04lx, 0x%p): ",
|
|
port->name, port->iobase, port->membase);
|
|
|
|
/*
|
|
* We really do need global IRQs disabled here - we're going to
|
|
* be frobbing the chips IRQ enable register to see if it exists.
|
|
*/
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
|
|
up->capabilities = 0;
|
|
up->bugs = 0;
|
|
|
|
if (!(port->flags & UPF_BUGGY_UART)) {
|
|
/*
|
|
* Do a simple existence test first; if we fail this,
|
|
* there's no point trying anything else.
|
|
*
|
|
* 0x80 is used as a nonsense port to prevent against
|
|
* false positives due to ISA bus float. The
|
|
* assumption is that 0x80 is a non-existent port;
|
|
* which should be safe since include/asm/io.h also
|
|
* makes this assumption.
|
|
*
|
|
* Note: this is safe as long as MCR bit 4 is clear
|
|
* and the device is in "PC" mode.
|
|
*/
|
|
scratch = serial_in(up, UART_IER);
|
|
serial_out(up, UART_IER, 0);
|
|
#ifdef __i386__
|
|
outb(0xff, 0x080);
|
|
#endif
|
|
/*
|
|
* Mask out IER[7:4] bits for test as some UARTs (e.g. TL
|
|
* 16C754B) allow only to modify them if an EFR bit is set.
|
|
*/
|
|
scratch2 = serial_in(up, UART_IER) & 0x0f;
|
|
serial_out(up, UART_IER, 0x0F);
|
|
#ifdef __i386__
|
|
outb(0, 0x080);
|
|
#endif
|
|
scratch3 = serial_in(up, UART_IER) & 0x0f;
|
|
serial_out(up, UART_IER, scratch);
|
|
if (scratch2 != 0 || scratch3 != 0x0F) {
|
|
/*
|
|
* We failed; there's nothing here
|
|
*/
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
|
|
scratch2, scratch3);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
save_mcr = serial8250_in_MCR(up);
|
|
save_lcr = serial_in(up, UART_LCR);
|
|
|
|
/*
|
|
* Check to see if a UART is really there. Certain broken
|
|
* internal modems based on the Rockwell chipset fail this
|
|
* test, because they apparently don't implement the loopback
|
|
* test mode. So this test is skipped on the COM 1 through
|
|
* COM 4 ports. This *should* be safe, since no board
|
|
* manufacturer would be stupid enough to design a board
|
|
* that conflicts with COM 1-4 --- we hope!
|
|
*/
|
|
if (!(port->flags & UPF_SKIP_TEST)) {
|
|
serial8250_out_MCR(up, UART_MCR_LOOP | 0x0A);
|
|
status1 = serial_in(up, UART_MSR) & 0xF0;
|
|
serial8250_out_MCR(up, save_mcr);
|
|
if (status1 != 0x90) {
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
DEBUG_AUTOCONF("LOOP test failed (%02x) ",
|
|
status1);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We're pretty sure there's a port here. Lets find out what
|
|
* type of port it is. The IIR top two bits allows us to find
|
|
* out if it's 8250 or 16450, 16550, 16550A or later. This
|
|
* determines what we test for next.
|
|
*
|
|
* We also initialise the EFR (if any) to zero for later. The
|
|
* EFR occupies the same register location as the FCR and IIR.
|
|
*/
|
|
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
|
|
serial_out(up, UART_EFR, 0);
|
|
serial_out(up, UART_LCR, 0);
|
|
|
|
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
|
|
|
|
/* Assign this as it is to truncate any bits above 7. */
|
|
scratch = serial_in(up, UART_IIR);
|
|
|
|
switch (scratch >> 6) {
|
|
case 0:
|
|
autoconfig_8250(up);
|
|
break;
|
|
case 1:
|
|
port->type = PORT_UNKNOWN;
|
|
break;
|
|
case 2:
|
|
port->type = PORT_16550;
|
|
break;
|
|
case 3:
|
|
autoconfig_16550a(up);
|
|
break;
|
|
}
|
|
|
|
#ifdef CONFIG_SERIAL_8250_RSA
|
|
/*
|
|
* Only probe for RSA ports if we got the region.
|
|
*/
|
|
if (port->type == PORT_16550A && up->probe & UART_PROBE_RSA &&
|
|
__enable_rsa(up))
|
|
port->type = PORT_RSA;
|
|
#endif
|
|
|
|
serial_out(up, UART_LCR, save_lcr);
|
|
|
|
port->fifosize = uart_config[up->port.type].fifo_size;
|
|
old_capabilities = up->capabilities;
|
|
up->capabilities = uart_config[port->type].flags;
|
|
up->tx_loadsz = uart_config[port->type].tx_loadsz;
|
|
|
|
if (port->type == PORT_UNKNOWN)
|
|
goto out_lock;
|
|
|
|
/*
|
|
* Reset the UART.
|
|
*/
|
|
#ifdef CONFIG_SERIAL_8250_RSA
|
|
if (port->type == PORT_RSA)
|
|
serial_out(up, UART_RSA_FRR, 0);
|
|
#endif
|
|
serial8250_out_MCR(up, save_mcr);
|
|
serial8250_clear_fifos(up);
|
|
serial_in(up, UART_RX);
|
|
if (up->capabilities & UART_CAP_UUE)
|
|
serial_out(up, UART_IER, UART_IER_UUE);
|
|
else
|
|
serial_out(up, UART_IER, 0);
|
|
|
|
out_lock:
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
/*
|
|
* Check if the device is a Fintek F81216A
|
|
*/
|
|
if (port->type == PORT_16550A && port->iotype == UPIO_PORT)
|
|
fintek_8250_probe(up);
|
|
|
|
if (up->capabilities != old_capabilities) {
|
|
dev_warn(port->dev, "detected caps %08x should be %08x\n",
|
|
old_capabilities, up->capabilities);
|
|
}
|
|
out:
|
|
DEBUG_AUTOCONF("iir=%d ", scratch);
|
|
DEBUG_AUTOCONF("type=%s\n", uart_config[port->type].name);
|
|
}
|
|
|
|
static void autoconfig_irq(struct uart_8250_port *up)
|
|
{
|
|
struct uart_port *port = &up->port;
|
|
unsigned char save_mcr, save_ier;
|
|
unsigned char save_ICP = 0;
|
|
unsigned int ICP = 0;
|
|
unsigned long irqs;
|
|
int irq;
|
|
|
|
if (port->flags & UPF_FOURPORT) {
|
|
ICP = (port->iobase & 0xfe0) | 0x1f;
|
|
save_ICP = inb_p(ICP);
|
|
outb_p(0x80, ICP);
|
|
inb_p(ICP);
|
|
}
|
|
|
|
if (uart_console(port))
|
|
console_lock();
|
|
|
|
/* forget possible initially masked and pending IRQ */
|
|
probe_irq_off(probe_irq_on());
|
|
save_mcr = serial8250_in_MCR(up);
|
|
save_ier = serial_in(up, UART_IER);
|
|
serial8250_out_MCR(up, UART_MCR_OUT1 | UART_MCR_OUT2);
|
|
|
|
irqs = probe_irq_on();
|
|
serial8250_out_MCR(up, 0);
|
|
udelay(10);
|
|
if (port->flags & UPF_FOURPORT) {
|
|
serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS);
|
|
} else {
|
|
serial8250_out_MCR(up,
|
|
UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
|
|
}
|
|
serial_out(up, UART_IER, 0x0f); /* enable all intrs */
|
|
serial_in(up, UART_LSR);
|
|
serial_in(up, UART_RX);
|
|
serial_in(up, UART_IIR);
|
|
serial_in(up, UART_MSR);
|
|
serial_out(up, UART_TX, 0xFF);
|
|
udelay(20);
|
|
irq = probe_irq_off(irqs);
|
|
|
|
serial8250_out_MCR(up, save_mcr);
|
|
serial_out(up, UART_IER, save_ier);
|
|
|
|
if (port->flags & UPF_FOURPORT)
|
|
outb_p(save_ICP, ICP);
|
|
|
|
if (uart_console(port))
|
|
console_unlock();
|
|
|
|
port->irq = (irq > 0) ? irq : 0;
|
|
}
|
|
|
|
static void serial8250_stop_rx(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
serial8250_rpm_get(up);
|
|
|
|
up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
|
|
up->port.read_status_mask &= ~UART_LSR_DR;
|
|
serial_port_out(port, UART_IER, up->ier);
|
|
|
|
serial8250_rpm_put(up);
|
|
}
|
|
|
|
/**
|
|
* serial8250_em485_stop_tx() - generic ->rs485_stop_tx() callback
|
|
* @p: uart 8250 port
|
|
*
|
|
* Generic callback usable by 8250 uart drivers to stop rs485 transmission.
|
|
*/
|
|
void serial8250_em485_stop_tx(struct uart_8250_port *p)
|
|
{
|
|
unsigned char mcr = serial8250_in_MCR(p);
|
|
|
|
if (p->port.rs485.flags & SER_RS485_RTS_AFTER_SEND)
|
|
mcr |= UART_MCR_RTS;
|
|
else
|
|
mcr &= ~UART_MCR_RTS;
|
|
serial8250_out_MCR(p, mcr);
|
|
|
|
/*
|
|
* Empty the RX FIFO, we are not interested in anything
|
|
* received during the half-duplex transmission.
|
|
* Enable previously disabled RX interrupts.
|
|
*/
|
|
if (!(p->port.rs485.flags & SER_RS485_RX_DURING_TX)) {
|
|
serial8250_clear_and_reinit_fifos(p);
|
|
|
|
p->ier |= UART_IER_RLSI | UART_IER_RDI;
|
|
serial_port_out(&p->port, UART_IER, p->ier);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_em485_stop_tx);
|
|
|
|
static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t)
|
|
{
|
|
struct uart_8250_em485 *em485 = container_of(t, struct uart_8250_em485,
|
|
stop_tx_timer);
|
|
struct uart_8250_port *p = em485->port;
|
|
unsigned long flags;
|
|
|
|
serial8250_rpm_get(p);
|
|
spin_lock_irqsave(&p->port.lock, flags);
|
|
if (em485->active_timer == &em485->stop_tx_timer) {
|
|
p->rs485_stop_tx(p);
|
|
em485->active_timer = NULL;
|
|
em485->tx_stopped = true;
|
|
}
|
|
spin_unlock_irqrestore(&p->port.lock, flags);
|
|
serial8250_rpm_put(p);
|
|
|
|
return HRTIMER_NORESTART;
|
|
}
|
|
|
|
static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec)
|
|
{
|
|
hrtimer_start(hrt, ms_to_ktime(msec), HRTIMER_MODE_REL);
|
|
}
|
|
|
|
static void __stop_tx_rs485(struct uart_8250_port *p)
|
|
{
|
|
struct uart_8250_em485 *em485 = p->em485;
|
|
|
|
/*
|
|
* rs485_stop_tx() is going to set RTS according to config
|
|
* AND flush RX FIFO if required.
|
|
*/
|
|
if (p->port.rs485.delay_rts_after_send > 0) {
|
|
em485->active_timer = &em485->stop_tx_timer;
|
|
start_hrtimer_ms(&em485->stop_tx_timer,
|
|
p->port.rs485.delay_rts_after_send);
|
|
} else {
|
|
p->rs485_stop_tx(p);
|
|
em485->active_timer = NULL;
|
|
em485->tx_stopped = true;
|
|
}
|
|
}
|
|
|
|
static inline void __do_stop_tx(struct uart_8250_port *p)
|
|
{
|
|
if (serial8250_clear_THRI(p))
|
|
serial8250_rpm_put_tx(p);
|
|
}
|
|
|
|
static inline void __stop_tx(struct uart_8250_port *p)
|
|
{
|
|
struct uart_8250_em485 *em485 = p->em485;
|
|
|
|
if (em485) {
|
|
unsigned char lsr = serial_in(p, UART_LSR);
|
|
/*
|
|
* To provide required timeing and allow FIFO transfer,
|
|
* __stop_tx_rs485() must be called only when both FIFO and
|
|
* shift register are empty. It is for device driver to enable
|
|
* interrupt on TEMT.
|
|
*/
|
|
if ((lsr & BOTH_EMPTY) != BOTH_EMPTY)
|
|
return;
|
|
|
|
__stop_tx_rs485(p);
|
|
}
|
|
__do_stop_tx(p);
|
|
}
|
|
|
|
static void serial8250_stop_tx(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
serial8250_rpm_get(up);
|
|
__stop_tx(up);
|
|
|
|
/*
|
|
* We really want to stop the transmitter from sending.
|
|
*/
|
|
if (port->type == PORT_16C950) {
|
|
up->acr |= UART_ACR_TXDIS;
|
|
serial_icr_write(up, UART_ACR, up->acr);
|
|
}
|
|
serial8250_rpm_put(up);
|
|
}
|
|
|
|
static inline void __start_tx(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
if (up->dma && !up->dma->tx_dma(up))
|
|
return;
|
|
|
|
if (serial8250_set_THRI(up)) {
|
|
if (up->bugs & UART_BUG_TXEN) {
|
|
unsigned char lsr;
|
|
|
|
lsr = serial_in(up, UART_LSR);
|
|
up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
|
|
if (lsr & UART_LSR_THRE)
|
|
serial8250_tx_chars(up);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Re-enable the transmitter if we disabled it.
|
|
*/
|
|
if (port->type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
|
|
up->acr &= ~UART_ACR_TXDIS;
|
|
serial_icr_write(up, UART_ACR, up->acr);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* serial8250_em485_start_tx() - generic ->rs485_start_tx() callback
|
|
* @up: uart 8250 port
|
|
*
|
|
* Generic callback usable by 8250 uart drivers to start rs485 transmission.
|
|
* Assumes that setting the RTS bit in the MCR register means RTS is high.
|
|
* (Some chips use inverse semantics.) Further assumes that reception is
|
|
* stoppable by disabling the UART_IER_RDI interrupt. (Some chips set the
|
|
* UART_LSR_DR bit even when UART_IER_RDI is disabled, foiling this approach.)
|
|
*/
|
|
void serial8250_em485_start_tx(struct uart_8250_port *up)
|
|
{
|
|
unsigned char mcr = serial8250_in_MCR(up);
|
|
|
|
if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
|
|
serial8250_stop_rx(&up->port);
|
|
|
|
if (up->port.rs485.flags & SER_RS485_RTS_ON_SEND)
|
|
mcr |= UART_MCR_RTS;
|
|
else
|
|
mcr &= ~UART_MCR_RTS;
|
|
serial8250_out_MCR(up, mcr);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_em485_start_tx);
|
|
|
|
static inline void start_tx_rs485(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
struct uart_8250_em485 *em485 = up->em485;
|
|
|
|
em485->active_timer = NULL;
|
|
|
|
if (em485->tx_stopped) {
|
|
em485->tx_stopped = false;
|
|
|
|
up->rs485_start_tx(up);
|
|
|
|
if (up->port.rs485.delay_rts_before_send > 0) {
|
|
em485->active_timer = &em485->start_tx_timer;
|
|
start_hrtimer_ms(&em485->start_tx_timer,
|
|
up->port.rs485.delay_rts_before_send);
|
|
return;
|
|
}
|
|
}
|
|
|
|
__start_tx(port);
|
|
}
|
|
|
|
static enum hrtimer_restart serial8250_em485_handle_start_tx(struct hrtimer *t)
|
|
{
|
|
struct uart_8250_em485 *em485 = container_of(t, struct uart_8250_em485,
|
|
start_tx_timer);
|
|
struct uart_8250_port *p = em485->port;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&p->port.lock, flags);
|
|
if (em485->active_timer == &em485->start_tx_timer) {
|
|
__start_tx(&p->port);
|
|
em485->active_timer = NULL;
|
|
}
|
|
spin_unlock_irqrestore(&p->port.lock, flags);
|
|
|
|
return HRTIMER_NORESTART;
|
|
}
|
|
|
|
static void serial8250_start_tx(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
struct uart_8250_em485 *em485 = up->em485;
|
|
|
|
serial8250_rpm_get_tx(up);
|
|
|
|
if (em485 &&
|
|
em485->active_timer == &em485->start_tx_timer)
|
|
return;
|
|
|
|
if (em485)
|
|
start_tx_rs485(port);
|
|
else
|
|
__start_tx(port);
|
|
}
|
|
|
|
static void serial8250_throttle(struct uart_port *port)
|
|
{
|
|
port->throttle(port);
|
|
}
|
|
|
|
static void serial8250_unthrottle(struct uart_port *port)
|
|
{
|
|
port->unthrottle(port);
|
|
}
|
|
|
|
static void serial8250_disable_ms(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
/* no MSR capabilities */
|
|
if (up->bugs & UART_BUG_NOMSR)
|
|
return;
|
|
|
|
mctrl_gpio_disable_ms(up->gpios);
|
|
|
|
up->ier &= ~UART_IER_MSI;
|
|
serial_port_out(port, UART_IER, up->ier);
|
|
}
|
|
|
|
static void serial8250_enable_ms(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
/* no MSR capabilities */
|
|
if (up->bugs & UART_BUG_NOMSR)
|
|
return;
|
|
|
|
mctrl_gpio_enable_ms(up->gpios);
|
|
|
|
up->ier |= UART_IER_MSI;
|
|
|
|
serial8250_rpm_get(up);
|
|
serial_port_out(port, UART_IER, up->ier);
|
|
serial8250_rpm_put(up);
|
|
}
|
|
|
|
void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr)
|
|
{
|
|
struct uart_port *port = &up->port;
|
|
unsigned char ch;
|
|
char flag = TTY_NORMAL;
|
|
|
|
if (likely(lsr & UART_LSR_DR))
|
|
ch = serial_in(up, UART_RX);
|
|
else
|
|
/*
|
|
* Intel 82571 has a Serial Over Lan device that will
|
|
* set UART_LSR_BI without setting UART_LSR_DR when
|
|
* it receives a break. To avoid reading from the
|
|
* receive buffer without UART_LSR_DR bit set, we
|
|
* just force the read character to be 0
|
|
*/
|
|
ch = 0;
|
|
|
|
port->icount.rx++;
|
|
|
|
lsr |= up->lsr_saved_flags;
|
|
up->lsr_saved_flags = 0;
|
|
|
|
if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
|
|
if (lsr & UART_LSR_BI) {
|
|
lsr &= ~(UART_LSR_FE | UART_LSR_PE);
|
|
port->icount.brk++;
|
|
/*
|
|
* We do the SysRQ and SAK checking
|
|
* here because otherwise the break
|
|
* may get masked by ignore_status_mask
|
|
* or read_status_mask.
|
|
*/
|
|
if (uart_handle_break(port))
|
|
return;
|
|
} else if (lsr & UART_LSR_PE)
|
|
port->icount.parity++;
|
|
else if (lsr & UART_LSR_FE)
|
|
port->icount.frame++;
|
|
if (lsr & UART_LSR_OE)
|
|
port->icount.overrun++;
|
|
|
|
/*
|
|
* Mask off conditions which should be ignored.
|
|
*/
|
|
lsr &= port->read_status_mask;
|
|
|
|
if (lsr & UART_LSR_BI) {
|
|
dev_dbg(port->dev, "handling break\n");
|
|
flag = TTY_BREAK;
|
|
} else if (lsr & UART_LSR_PE)
|
|
flag = TTY_PARITY;
|
|
else if (lsr & UART_LSR_FE)
|
|
flag = TTY_FRAME;
|
|
}
|
|
if (uart_prepare_sysrq_char(port, ch))
|
|
return;
|
|
|
|
uart_insert_char(port, lsr, UART_LSR_OE, ch, flag);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_read_char);
|
|
|
|
/*
|
|
* serial8250_rx_chars: processes according to the passed in LSR
|
|
* value, and returns the remaining LSR bits not handled
|
|
* by this Rx routine.
|
|
*/
|
|
unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr)
|
|
{
|
|
struct uart_port *port = &up->port;
|
|
int max_count = 256;
|
|
|
|
do {
|
|
serial8250_read_char(up, lsr);
|
|
if (--max_count == 0)
|
|
break;
|
|
lsr = serial_in(up, UART_LSR);
|
|
} while (lsr & (UART_LSR_DR | UART_LSR_BI));
|
|
|
|
tty_flip_buffer_push(&port->state->port);
|
|
return lsr;
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_rx_chars);
|
|
|
|
void serial8250_tx_chars(struct uart_8250_port *up)
|
|
{
|
|
struct uart_port *port = &up->port;
|
|
struct circ_buf *xmit = &port->state->xmit;
|
|
int count;
|
|
|
|
if (port->x_char) {
|
|
serial_out(up, UART_TX, port->x_char);
|
|
port->icount.tx++;
|
|
port->x_char = 0;
|
|
return;
|
|
}
|
|
if (uart_tx_stopped(port)) {
|
|
serial8250_stop_tx(port);
|
|
return;
|
|
}
|
|
if (uart_circ_empty(xmit)) {
|
|
__stop_tx(up);
|
|
return;
|
|
}
|
|
|
|
count = up->tx_loadsz;
|
|
do {
|
|
serial_out(up, UART_TX, xmit->buf[xmit->tail]);
|
|
if (up->bugs & UART_BUG_TXRACE) {
|
|
/*
|
|
* The Aspeed BMC virtual UARTs have a bug where data
|
|
* may get stuck in the BMC's Tx FIFO from bursts of
|
|
* writes on the APB interface.
|
|
*
|
|
* Delay back-to-back writes by a read cycle to avoid
|
|
* stalling the VUART. Read a register that won't have
|
|
* side-effects and discard the result.
|
|
*/
|
|
serial_in(up, UART_SCR);
|
|
}
|
|
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
|
|
port->icount.tx++;
|
|
if (uart_circ_empty(xmit))
|
|
break;
|
|
if ((up->capabilities & UART_CAP_HFIFO) &&
|
|
(serial_in(up, UART_LSR) & BOTH_EMPTY) != BOTH_EMPTY)
|
|
break;
|
|
/* The BCM2835 MINI UART THRE bit is really a not-full bit. */
|
|
if ((up->capabilities & UART_CAP_MINI) &&
|
|
!(serial_in(up, UART_LSR) & UART_LSR_THRE))
|
|
break;
|
|
} while (--count > 0);
|
|
|
|
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
|
|
uart_write_wakeup(port);
|
|
|
|
/*
|
|
* With RPM enabled, we have to wait until the FIFO is empty before the
|
|
* HW can go idle. So we get here once again with empty FIFO and disable
|
|
* the interrupt and RPM in __stop_tx()
|
|
*/
|
|
if (uart_circ_empty(xmit) && !(up->capabilities & UART_CAP_RPM))
|
|
__stop_tx(up);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_tx_chars);
|
|
|
|
/* Caller holds uart port lock */
|
|
unsigned int serial8250_modem_status(struct uart_8250_port *up)
|
|
{
|
|
struct uart_port *port = &up->port;
|
|
unsigned int status = serial_in(up, UART_MSR);
|
|
|
|
status |= up->msr_saved_flags;
|
|
up->msr_saved_flags = 0;
|
|
if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
|
|
port->state != NULL) {
|
|
if (status & UART_MSR_TERI)
|
|
port->icount.rng++;
|
|
if (status & UART_MSR_DDSR)
|
|
port->icount.dsr++;
|
|
if (status & UART_MSR_DDCD)
|
|
uart_handle_dcd_change(port, status & UART_MSR_DCD);
|
|
if (status & UART_MSR_DCTS)
|
|
uart_handle_cts_change(port, status & UART_MSR_CTS);
|
|
|
|
wake_up_interruptible(&port->state->port.delta_msr_wait);
|
|
}
|
|
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_modem_status);
|
|
|
|
static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir)
|
|
{
|
|
switch (iir & 0x3f) {
|
|
case UART_IIR_RX_TIMEOUT:
|
|
serial8250_rx_dma_flush(up);
|
|
fallthrough;
|
|
case UART_IIR_RLSI:
|
|
return true;
|
|
}
|
|
return up->dma->rx_dma(up);
|
|
}
|
|
|
|
/*
|
|
* This handles the interrupt from one port.
|
|
*/
|
|
int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
|
|
{
|
|
unsigned char status;
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
bool skip_rx = false;
|
|
unsigned long flags;
|
|
|
|
if (iir & UART_IIR_NO_INT)
|
|
return 0;
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
|
|
status = serial_port_in(port, UART_LSR);
|
|
|
|
/*
|
|
* If port is stopped and there are no error conditions in the
|
|
* FIFO, then don't drain the FIFO, as this may lead to TTY buffer
|
|
* overflow. Not servicing, RX FIFO would trigger auto HW flow
|
|
* control when FIFO occupancy reaches preset threshold, thus
|
|
* halting RX. This only works when auto HW flow control is
|
|
* available.
|
|
*/
|
|
if (!(status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS)) &&
|
|
(port->status & (UPSTAT_AUTOCTS | UPSTAT_AUTORTS)) &&
|
|
!(port->read_status_mask & UART_LSR_DR))
|
|
skip_rx = true;
|
|
|
|
if (status & (UART_LSR_DR | UART_LSR_BI) && !skip_rx) {
|
|
if (!up->dma || handle_rx_dma(up, iir))
|
|
status = serial8250_rx_chars(up, status);
|
|
}
|
|
serial8250_modem_status(up);
|
|
if ((!up->dma || up->dma->tx_err) && (status & UART_LSR_THRE) &&
|
|
(up->ier & UART_IER_THRI))
|
|
serial8250_tx_chars(up);
|
|
|
|
uart_unlock_and_check_sysrq_irqrestore(port, flags);
|
|
|
|
return 1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_handle_irq);
|
|
|
|
static int serial8250_default_handle_irq(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
unsigned int iir;
|
|
int ret;
|
|
|
|
serial8250_rpm_get(up);
|
|
|
|
iir = serial_port_in(port, UART_IIR);
|
|
ret = serial8250_handle_irq(port, iir);
|
|
|
|
serial8250_rpm_put(up);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Newer 16550 compatible parts such as the SC16C650 & Altera 16550 Soft IP
|
|
* have a programmable TX threshold that triggers the THRE interrupt in
|
|
* the IIR register. In this case, the THRE interrupt indicates the FIFO
|
|
* has space available. Load it up with tx_loadsz bytes.
|
|
*/
|
|
static int serial8250_tx_threshold_handle_irq(struct uart_port *port)
|
|
{
|
|
unsigned long flags;
|
|
unsigned int iir = serial_port_in(port, UART_IIR);
|
|
|
|
/* TX Threshold IRQ triggered so load up FIFO */
|
|
if ((iir & UART_IIR_ID) == UART_IIR_THRI) {
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
serial8250_tx_chars(up);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
|
|
iir = serial_port_in(port, UART_IIR);
|
|
return serial8250_handle_irq(port, iir);
|
|
}
|
|
|
|
static unsigned int serial8250_tx_empty(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
unsigned long flags;
|
|
unsigned int lsr;
|
|
|
|
serial8250_rpm_get(up);
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
lsr = serial_port_in(port, UART_LSR);
|
|
up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
serial8250_rpm_put(up);
|
|
|
|
return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0;
|
|
}
|
|
|
|
unsigned int serial8250_do_get_mctrl(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
unsigned int status;
|
|
unsigned int val;
|
|
|
|
serial8250_rpm_get(up);
|
|
status = serial8250_modem_status(up);
|
|
serial8250_rpm_put(up);
|
|
|
|
val = serial8250_MSR_to_TIOCM(status);
|
|
if (up->gpios)
|
|
return mctrl_gpio_get(up->gpios, &val);
|
|
|
|
return val;
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl);
|
|
|
|
static unsigned int serial8250_get_mctrl(struct uart_port *port)
|
|
{
|
|
if (port->get_mctrl)
|
|
return port->get_mctrl(port);
|
|
return serial8250_do_get_mctrl(port);
|
|
}
|
|
|
|
void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
unsigned char mcr;
|
|
|
|
if (port->rs485.flags & SER_RS485_ENABLED) {
|
|
if (serial8250_in_MCR(up) & UART_MCR_RTS)
|
|
mctrl |= TIOCM_RTS;
|
|
else
|
|
mctrl &= ~TIOCM_RTS;
|
|
}
|
|
|
|
mcr = serial8250_TIOCM_to_MCR(mctrl);
|
|
|
|
mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
|
|
|
|
serial8250_out_MCR(up, mcr);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_do_set_mctrl);
|
|
|
|
static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
|
|
{
|
|
if (port->set_mctrl)
|
|
port->set_mctrl(port, mctrl);
|
|
else
|
|
serial8250_do_set_mctrl(port, mctrl);
|
|
}
|
|
|
|
static void serial8250_break_ctl(struct uart_port *port, int break_state)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
unsigned long flags;
|
|
|
|
serial8250_rpm_get(up);
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
if (break_state == -1)
|
|
up->lcr |= UART_LCR_SBC;
|
|
else
|
|
up->lcr &= ~UART_LCR_SBC;
|
|
serial_port_out(port, UART_LCR, up->lcr);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
serial8250_rpm_put(up);
|
|
}
|
|
|
|
/*
|
|
* Wait for transmitter & holding register to empty
|
|
*/
|
|
static void wait_for_xmitr(struct uart_8250_port *up, int bits)
|
|
{
|
|
unsigned int status, tmout = 10000;
|
|
|
|
/* Wait up to 10ms for the character(s) to be sent. */
|
|
for (;;) {
|
|
status = serial_in(up, UART_LSR);
|
|
|
|
up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
|
|
|
|
if ((status & bits) == bits)
|
|
break;
|
|
if (--tmout == 0)
|
|
break;
|
|
udelay(1);
|
|
touch_nmi_watchdog();
|
|
}
|
|
|
|
/* Wait up to 1s for flow control if necessary */
|
|
if (up->port.flags & UPF_CONS_FLOW) {
|
|
for (tmout = 1000000; tmout; tmout--) {
|
|
unsigned int msr = serial_in(up, UART_MSR);
|
|
up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
|
|
if (msr & UART_MSR_CTS)
|
|
break;
|
|
udelay(1);
|
|
touch_nmi_watchdog();
|
|
}
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_CONSOLE_POLL
|
|
/*
|
|
* Console polling routines for writing and reading from the uart while
|
|
* in an interrupt or debug context.
|
|
*/
|
|
|
|
static int serial8250_get_poll_char(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
unsigned char lsr;
|
|
int status;
|
|
|
|
serial8250_rpm_get(up);
|
|
|
|
lsr = serial_port_in(port, UART_LSR);
|
|
|
|
if (!(lsr & UART_LSR_DR)) {
|
|
status = NO_POLL_CHAR;
|
|
goto out;
|
|
}
|
|
|
|
status = serial_port_in(port, UART_RX);
|
|
out:
|
|
serial8250_rpm_put(up);
|
|
return status;
|
|
}
|
|
|
|
|
|
static void serial8250_put_poll_char(struct uart_port *port,
|
|
unsigned char c)
|
|
{
|
|
unsigned int ier;
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
serial8250_rpm_get(up);
|
|
/*
|
|
* First save the IER then disable the interrupts
|
|
*/
|
|
ier = serial_port_in(port, UART_IER);
|
|
if (up->capabilities & UART_CAP_UUE)
|
|
serial_port_out(port, UART_IER, UART_IER_UUE);
|
|
else
|
|
serial_port_out(port, UART_IER, 0);
|
|
|
|
wait_for_xmitr(up, BOTH_EMPTY);
|
|
/*
|
|
* Send the character out.
|
|
*/
|
|
serial_port_out(port, UART_TX, c);
|
|
|
|
/*
|
|
* Finally, wait for transmitter to become empty
|
|
* and restore the IER
|
|
*/
|
|
wait_for_xmitr(up, BOTH_EMPTY);
|
|
serial_port_out(port, UART_IER, ier);
|
|
serial8250_rpm_put(up);
|
|
}
|
|
|
|
#endif /* CONFIG_CONSOLE_POLL */
|
|
|
|
int serial8250_do_startup(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
unsigned long flags;
|
|
unsigned char lsr, iir;
|
|
int retval;
|
|
|
|
if (!port->fifosize)
|
|
port->fifosize = uart_config[port->type].fifo_size;
|
|
if (!up->tx_loadsz)
|
|
up->tx_loadsz = uart_config[port->type].tx_loadsz;
|
|
if (!up->capabilities)
|
|
up->capabilities = uart_config[port->type].flags;
|
|
up->mcr = 0;
|
|
|
|
if (port->iotype != up->cur_iotype)
|
|
set_io_from_upio(port);
|
|
|
|
serial8250_rpm_get(up);
|
|
if (port->type == PORT_16C950) {
|
|
/* Wake up and initialize UART */
|
|
up->acr = 0;
|
|
serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
|
|
serial_port_out(port, UART_EFR, UART_EFR_ECB);
|
|
serial_port_out(port, UART_IER, 0);
|
|
serial_port_out(port, UART_LCR, 0);
|
|
serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
|
|
serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
|
|
serial_port_out(port, UART_EFR, UART_EFR_ECB);
|
|
serial_port_out(port, UART_LCR, 0);
|
|
}
|
|
|
|
if (port->type == PORT_DA830) {
|
|
/* Reset the port */
|
|
serial_port_out(port, UART_IER, 0);
|
|
serial_port_out(port, UART_DA830_PWREMU_MGMT, 0);
|
|
mdelay(10);
|
|
|
|
/* Enable Tx, Rx and free run mode */
|
|
serial_port_out(port, UART_DA830_PWREMU_MGMT,
|
|
UART_DA830_PWREMU_MGMT_UTRST |
|
|
UART_DA830_PWREMU_MGMT_URRST |
|
|
UART_DA830_PWREMU_MGMT_FREE);
|
|
}
|
|
|
|
if (port->type == PORT_NPCM) {
|
|
/*
|
|
* Nuvoton calls the scratch register 'UART_TOR' (timeout
|
|
* register). Enable it, and set TIOC (timeout interrupt
|
|
* comparator) to be 0x20 for correct operation.
|
|
*/
|
|
serial_port_out(port, UART_NPCM_TOR, UART_NPCM_TOIE | 0x20);
|
|
}
|
|
|
|
#ifdef CONFIG_SERIAL_8250_RSA
|
|
/*
|
|
* If this is an RSA port, see if we can kick it up to the
|
|
* higher speed clock.
|
|
*/
|
|
enable_rsa(up);
|
|
#endif
|
|
|
|
/*
|
|
* Clear the FIFO buffers and disable them.
|
|
* (they will be reenabled in set_termios())
|
|
*/
|
|
serial8250_clear_fifos(up);
|
|
|
|
/*
|
|
* Clear the interrupt registers.
|
|
*/
|
|
serial_port_in(port, UART_LSR);
|
|
serial_port_in(port, UART_RX);
|
|
serial_port_in(port, UART_IIR);
|
|
serial_port_in(port, UART_MSR);
|
|
|
|
/*
|
|
* At this point, there's no way the LSR could still be 0xff;
|
|
* if it is, then bail out, because there's likely no UART
|
|
* here.
|
|
*/
|
|
if (!(port->flags & UPF_BUGGY_UART) &&
|
|
(serial_port_in(port, UART_LSR) == 0xff)) {
|
|
dev_info_ratelimited(port->dev, "LSR safety check engaged!\n");
|
|
retval = -ENODEV;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* For a XR16C850, we need to set the trigger levels
|
|
*/
|
|
if (port->type == PORT_16850) {
|
|
unsigned char fctr;
|
|
|
|
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
|
|
|
|
fctr = serial_in(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
|
|
serial_port_out(port, UART_FCTR,
|
|
fctr | UART_FCTR_TRGD | UART_FCTR_RX);
|
|
serial_port_out(port, UART_TRG, UART_TRG_96);
|
|
serial_port_out(port, UART_FCTR,
|
|
fctr | UART_FCTR_TRGD | UART_FCTR_TX);
|
|
serial_port_out(port, UART_TRG, UART_TRG_96);
|
|
|
|
serial_port_out(port, UART_LCR, 0);
|
|
}
|
|
|
|
/*
|
|
* For the Altera 16550 variants, set TX threshold trigger level.
|
|
*/
|
|
if (((port->type == PORT_ALTR_16550_F32) ||
|
|
(port->type == PORT_ALTR_16550_F64) ||
|
|
(port->type == PORT_ALTR_16550_F128)) && (port->fifosize > 1)) {
|
|
/* Bounds checking of TX threshold (valid 0 to fifosize-2) */
|
|
if ((up->tx_loadsz < 2) || (up->tx_loadsz > port->fifosize)) {
|
|
dev_err(port->dev, "TX FIFO Threshold errors, skipping\n");
|
|
} else {
|
|
serial_port_out(port, UART_ALTR_AFR,
|
|
UART_ALTR_EN_TXFIFO_LW);
|
|
serial_port_out(port, UART_ALTR_TX_LOW,
|
|
port->fifosize - up->tx_loadsz);
|
|
port->handle_irq = serial8250_tx_threshold_handle_irq;
|
|
}
|
|
}
|
|
|
|
/* Check if we need to have shared IRQs */
|
|
if (port->irq && (up->port.flags & UPF_SHARE_IRQ))
|
|
up->port.irqflags |= IRQF_SHARED;
|
|
|
|
if (port->irq && !(up->port.flags & UPF_NO_THRE_TEST)) {
|
|
unsigned char iir1;
|
|
|
|
if (port->irqflags & IRQF_SHARED)
|
|
disable_irq_nosync(port->irq);
|
|
|
|
/*
|
|
* Test for UARTs that do not reassert THRE when the
|
|
* transmitter is idle and the interrupt has already
|
|
* been cleared. Real 16550s should always reassert
|
|
* this interrupt whenever the transmitter is idle and
|
|
* the interrupt is enabled. Delays are necessary to
|
|
* allow register changes to become visible.
|
|
*/
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
|
|
wait_for_xmitr(up, UART_LSR_THRE);
|
|
serial_port_out_sync(port, UART_IER, UART_IER_THRI);
|
|
udelay(1); /* allow THRE to set */
|
|
iir1 = serial_port_in(port, UART_IIR);
|
|
serial_port_out(port, UART_IER, 0);
|
|
serial_port_out_sync(port, UART_IER, UART_IER_THRI);
|
|
udelay(1); /* allow a working UART time to re-assert THRE */
|
|
iir = serial_port_in(port, UART_IIR);
|
|
serial_port_out(port, UART_IER, 0);
|
|
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
if (port->irqflags & IRQF_SHARED)
|
|
enable_irq(port->irq);
|
|
|
|
/*
|
|
* If the interrupt is not reasserted, or we otherwise
|
|
* don't trust the iir, setup a timer to kick the UART
|
|
* on a regular basis.
|
|
*/
|
|
if ((!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) ||
|
|
up->port.flags & UPF_BUG_THRE) {
|
|
up->bugs |= UART_BUG_THRE;
|
|
}
|
|
}
|
|
|
|
retval = up->ops->setup_irq(up);
|
|
if (retval)
|
|
goto out;
|
|
|
|
/*
|
|
* Now, initialize the UART
|
|
*/
|
|
serial_port_out(port, UART_LCR, UART_LCR_WLEN8);
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
if (up->port.flags & UPF_FOURPORT) {
|
|
if (!up->port.irq)
|
|
up->port.mctrl |= TIOCM_OUT1;
|
|
} else
|
|
/*
|
|
* Most PC uarts need OUT2 raised to enable interrupts.
|
|
*/
|
|
if (port->irq)
|
|
up->port.mctrl |= TIOCM_OUT2;
|
|
|
|
serial8250_set_mctrl(port, port->mctrl);
|
|
|
|
/*
|
|
* Serial over Lan (SoL) hack:
|
|
* Intel 8257x Gigabit ethernet chips have a 16550 emulation, to be
|
|
* used for Serial Over Lan. Those chips take a longer time than a
|
|
* normal serial device to signalize that a transmission data was
|
|
* queued. Due to that, the above test generally fails. One solution
|
|
* would be to delay the reading of iir. However, this is not
|
|
* reliable, since the timeout is variable. So, let's just don't
|
|
* test if we receive TX irq. This way, we'll never enable
|
|
* UART_BUG_TXEN.
|
|
*/
|
|
if (up->port.quirks & UPQ_NO_TXEN_TEST)
|
|
goto dont_test_tx_en;
|
|
|
|
/*
|
|
* Do a quick test to see if we receive an interrupt when we enable
|
|
* the TX irq.
|
|
*/
|
|
serial_port_out(port, UART_IER, UART_IER_THRI);
|
|
lsr = serial_port_in(port, UART_LSR);
|
|
iir = serial_port_in(port, UART_IIR);
|
|
serial_port_out(port, UART_IER, 0);
|
|
|
|
if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
|
|
if (!(up->bugs & UART_BUG_TXEN)) {
|
|
up->bugs |= UART_BUG_TXEN;
|
|
dev_dbg(port->dev, "enabling bad tx status workarounds\n");
|
|
}
|
|
} else {
|
|
up->bugs &= ~UART_BUG_TXEN;
|
|
}
|
|
|
|
dont_test_tx_en:
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
/*
|
|
* Clear the interrupt registers again for luck, and clear the
|
|
* saved flags to avoid getting false values from polling
|
|
* routines or the previous session.
|
|
*/
|
|
serial_port_in(port, UART_LSR);
|
|
serial_port_in(port, UART_RX);
|
|
serial_port_in(port, UART_IIR);
|
|
serial_port_in(port, UART_MSR);
|
|
up->lsr_saved_flags = 0;
|
|
up->msr_saved_flags = 0;
|
|
|
|
/*
|
|
* Request DMA channels for both RX and TX.
|
|
*/
|
|
if (up->dma) {
|
|
const char *msg = NULL;
|
|
|
|
if (uart_console(port))
|
|
msg = "forbid DMA for kernel console";
|
|
else if (serial8250_request_dma(up))
|
|
msg = "failed to request DMA";
|
|
if (msg) {
|
|
dev_warn_ratelimited(port->dev, "%s\n", msg);
|
|
up->dma = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set the IER shadow for rx interrupts but defer actual interrupt
|
|
* enable until after the FIFOs are enabled; otherwise, an already-
|
|
* active sender can swamp the interrupt handler with "too much work".
|
|
*/
|
|
up->ier = UART_IER_RLSI | UART_IER_RDI;
|
|
|
|
if (port->flags & UPF_FOURPORT) {
|
|
unsigned int icp;
|
|
/*
|
|
* Enable interrupts on the AST Fourport board
|
|
*/
|
|
icp = (port->iobase & 0xfe0) | 0x01f;
|
|
outb_p(0x80, icp);
|
|
inb_p(icp);
|
|
}
|
|
retval = 0;
|
|
out:
|
|
serial8250_rpm_put(up);
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_do_startup);
|
|
|
|
static int serial8250_startup(struct uart_port *port)
|
|
{
|
|
if (port->startup)
|
|
return port->startup(port);
|
|
return serial8250_do_startup(port);
|
|
}
|
|
|
|
void serial8250_do_shutdown(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
unsigned long flags;
|
|
|
|
serial8250_rpm_get(up);
|
|
/*
|
|
* Disable interrupts from this port
|
|
*/
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
up->ier = 0;
|
|
serial_port_out(port, UART_IER, 0);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
synchronize_irq(port->irq);
|
|
|
|
if (up->dma)
|
|
serial8250_release_dma(up);
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
if (port->flags & UPF_FOURPORT) {
|
|
/* reset interrupts on the AST Fourport board */
|
|
inb((port->iobase & 0xfe0) | 0x1f);
|
|
port->mctrl |= TIOCM_OUT1;
|
|
} else
|
|
port->mctrl &= ~TIOCM_OUT2;
|
|
|
|
serial8250_set_mctrl(port, port->mctrl);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
/*
|
|
* Disable break condition and FIFOs
|
|
*/
|
|
serial_port_out(port, UART_LCR,
|
|
serial_port_in(port, UART_LCR) & ~UART_LCR_SBC);
|
|
serial8250_clear_fifos(up);
|
|
|
|
#ifdef CONFIG_SERIAL_8250_RSA
|
|
/*
|
|
* Reset the RSA board back to 115kbps compat mode.
|
|
*/
|
|
disable_rsa(up);
|
|
#endif
|
|
|
|
/*
|
|
* Read data port to reset things, and then unlink from
|
|
* the IRQ chain.
|
|
*/
|
|
serial_port_in(port, UART_RX);
|
|
serial8250_rpm_put(up);
|
|
|
|
up->ops->release_irq(up);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_do_shutdown);
|
|
|
|
static void serial8250_shutdown(struct uart_port *port)
|
|
{
|
|
if (port->shutdown)
|
|
port->shutdown(port);
|
|
else
|
|
serial8250_do_shutdown(port);
|
|
}
|
|
|
|
/* Nuvoton NPCM UARTs have a custom divisor calculation */
|
|
static unsigned int npcm_get_divisor(struct uart_8250_port *up,
|
|
unsigned int baud)
|
|
{
|
|
struct uart_port *port = &up->port;
|
|
|
|
return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2;
|
|
}
|
|
|
|
static unsigned int serial8250_do_get_divisor(struct uart_port *port,
|
|
unsigned int baud,
|
|
unsigned int *frac)
|
|
{
|
|
upf_t magic_multiplier = port->flags & UPF_MAGIC_MULTIPLIER;
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
unsigned int quot;
|
|
|
|
/*
|
|
* Handle magic divisors for baud rates above baud_base on SMSC
|
|
* Super I/O chips. We clamp custom rates from clk/6 and clk/12
|
|
* up to clk/4 (0x8001) and clk/8 (0x8002) respectively. These
|
|
* magic divisors actually reprogram the baud rate generator's
|
|
* reference clock derived from chips's 14.318MHz clock input.
|
|
*
|
|
* Documentation claims that with these magic divisors the base
|
|
* frequencies of 7.3728MHz and 3.6864MHz are used respectively
|
|
* for the extra baud rates of 460800bps and 230400bps rather
|
|
* than the usual base frequency of 1.8462MHz. However empirical
|
|
* evidence contradicts that.
|
|
*
|
|
* Instead bit 7 of the DLM register (bit 15 of the divisor) is
|
|
* effectively used as a clock prescaler selection bit for the
|
|
* base frequency of 7.3728MHz, always used. If set to 0, then
|
|
* the base frequency is divided by 4 for use by the Baud Rate
|
|
* Generator, for the usual arrangement where the value of 1 of
|
|
* the divisor produces the baud rate of 115200bps. Conversely,
|
|
* if set to 1 and high-speed operation has been enabled with the
|
|
* Serial Port Mode Register in the Device Configuration Space,
|
|
* then the base frequency is supplied directly to the Baud Rate
|
|
* Generator, so for the divisor values of 0x8001, 0x8002, 0x8003,
|
|
* 0x8004, etc. the respective baud rates produced are 460800bps,
|
|
* 230400bps, 153600bps, 115200bps, etc.
|
|
*
|
|
* In all cases only low 15 bits of the divisor are used to divide
|
|
* the baud base and therefore 32767 is the maximum divisor value
|
|
* possible, even though documentation says that the programmable
|
|
* Baud Rate Generator is capable of dividing the internal PLL
|
|
* clock by any divisor from 1 to 65535.
|
|
*/
|
|
if (magic_multiplier && baud >= port->uartclk / 6)
|
|
quot = 0x8001;
|
|
else if (magic_multiplier && baud >= port->uartclk / 12)
|
|
quot = 0x8002;
|
|
else if (up->port.type == PORT_NPCM)
|
|
quot = npcm_get_divisor(up, baud);
|
|
else
|
|
quot = uart_get_divisor(port, baud);
|
|
|
|
/*
|
|
* Oxford Semi 952 rev B workaround
|
|
*/
|
|
if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
|
|
quot++;
|
|
|
|
return quot;
|
|
}
|
|
|
|
static unsigned int serial8250_get_divisor(struct uart_port *port,
|
|
unsigned int baud,
|
|
unsigned int *frac)
|
|
{
|
|
if (port->get_divisor)
|
|
return port->get_divisor(port, baud, frac);
|
|
|
|
return serial8250_do_get_divisor(port, baud, frac);
|
|
}
|
|
|
|
static unsigned char serial8250_compute_lcr(struct uart_8250_port *up,
|
|
tcflag_t c_cflag)
|
|
{
|
|
unsigned char cval;
|
|
|
|
switch (c_cflag & CSIZE) {
|
|
case CS5:
|
|
cval = UART_LCR_WLEN5;
|
|
break;
|
|
case CS6:
|
|
cval = UART_LCR_WLEN6;
|
|
break;
|
|
case CS7:
|
|
cval = UART_LCR_WLEN7;
|
|
break;
|
|
default:
|
|
case CS8:
|
|
cval = UART_LCR_WLEN8;
|
|
break;
|
|
}
|
|
|
|
if (c_cflag & CSTOPB)
|
|
cval |= UART_LCR_STOP;
|
|
if (c_cflag & PARENB) {
|
|
cval |= UART_LCR_PARITY;
|
|
if (up->bugs & UART_BUG_PARITY)
|
|
up->fifo_bug = true;
|
|
}
|
|
if (!(c_cflag & PARODD))
|
|
cval |= UART_LCR_EPAR;
|
|
#ifdef CMSPAR
|
|
if (c_cflag & CMSPAR)
|
|
cval |= UART_LCR_SPAR;
|
|
#endif
|
|
|
|
return cval;
|
|
}
|
|
|
|
void serial8250_do_set_divisor(struct uart_port *port, unsigned int baud,
|
|
unsigned int quot, unsigned int quot_frac)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
/* Workaround to enable 115200 baud on OMAP1510 internal ports */
|
|
if (is_omap1510_8250(up)) {
|
|
if (baud == 115200) {
|
|
quot = 1;
|
|
serial_port_out(port, UART_OMAP_OSC_12M_SEL, 1);
|
|
} else
|
|
serial_port_out(port, UART_OMAP_OSC_12M_SEL, 0);
|
|
}
|
|
|
|
/*
|
|
* For NatSemi, switch to bank 2 not bank 1, to avoid resetting EXCR2,
|
|
* otherwise just set DLAB
|
|
*/
|
|
if (up->capabilities & UART_NATSEMI)
|
|
serial_port_out(port, UART_LCR, 0xe0);
|
|
else
|
|
serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB);
|
|
|
|
serial_dl_write(up, quot);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_do_set_divisor);
|
|
|
|
static void serial8250_set_divisor(struct uart_port *port, unsigned int baud,
|
|
unsigned int quot, unsigned int quot_frac)
|
|
{
|
|
if (port->set_divisor)
|
|
port->set_divisor(port, baud, quot, quot_frac);
|
|
else
|
|
serial8250_do_set_divisor(port, baud, quot, quot_frac);
|
|
}
|
|
|
|
static unsigned int serial8250_get_baud_rate(struct uart_port *port,
|
|
struct ktermios *termios,
|
|
struct ktermios *old)
|
|
{
|
|
unsigned int tolerance = port->uartclk / 100;
|
|
unsigned int min;
|
|
unsigned int max;
|
|
|
|
/*
|
|
* Handle magic divisors for baud rates above baud_base on SMSC
|
|
* Super I/O chips. Enable custom rates of clk/4 and clk/8, but
|
|
* disable divisor values beyond 32767, which are unavailable.
|
|
*/
|
|
if (port->flags & UPF_MAGIC_MULTIPLIER) {
|
|
min = port->uartclk / 16 / UART_DIV_MAX >> 1;
|
|
max = (port->uartclk + tolerance) / 4;
|
|
} else {
|
|
min = port->uartclk / 16 / UART_DIV_MAX;
|
|
max = (port->uartclk + tolerance) / 16;
|
|
}
|
|
|
|
/*
|
|
* Ask the core to calculate the divisor for us.
|
|
* Allow 1% tolerance at the upper limit so uart clks marginally
|
|
* slower than nominal still match standard baud rates without
|
|
* causing transmission errors.
|
|
*/
|
|
return uart_get_baud_rate(port, termios, old, min, max);
|
|
}
|
|
|
|
/*
|
|
* Note in order to avoid the tty port mutex deadlock don't use the next method
|
|
* within the uart port callbacks. Primarily it's supposed to be utilized to
|
|
* handle a sudden reference clock rate change.
|
|
*/
|
|
void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
unsigned int baud, quot, frac = 0;
|
|
struct ktermios *termios;
|
|
unsigned long flags;
|
|
|
|
mutex_lock(&port->state->port.mutex);
|
|
|
|
if (port->uartclk == uartclk)
|
|
goto out_lock;
|
|
|
|
port->uartclk = uartclk;
|
|
|
|
if (!tty_port_initialized(&port->state->port))
|
|
goto out_lock;
|
|
|
|
termios = &port->state->port.tty->termios;
|
|
|
|
baud = serial8250_get_baud_rate(port, termios, NULL);
|
|
quot = serial8250_get_divisor(port, baud, &frac);
|
|
|
|
serial8250_rpm_get(up);
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
|
|
uart_update_timeout(port, termios->c_cflag, baud);
|
|
|
|
serial8250_set_divisor(port, baud, quot, frac);
|
|
serial_port_out(port, UART_LCR, up->lcr);
|
|
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
serial8250_rpm_put(up);
|
|
|
|
out_lock:
|
|
mutex_unlock(&port->state->port.mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_update_uartclk);
|
|
|
|
void
|
|
serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
|
|
struct ktermios *old)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
unsigned char cval;
|
|
unsigned long flags;
|
|
unsigned int baud, quot, frac = 0;
|
|
|
|
if (up->capabilities & UART_CAP_MINI) {
|
|
termios->c_cflag &= ~(CSTOPB | PARENB | PARODD | CMSPAR);
|
|
if ((termios->c_cflag & CSIZE) == CS5 ||
|
|
(termios->c_cflag & CSIZE) == CS6)
|
|
termios->c_cflag = (termios->c_cflag & ~CSIZE) | CS7;
|
|
}
|
|
cval = serial8250_compute_lcr(up, termios->c_cflag);
|
|
|
|
baud = serial8250_get_baud_rate(port, termios, old);
|
|
quot = serial8250_get_divisor(port, baud, &frac);
|
|
|
|
/*
|
|
* Ok, we're now changing the port state. Do it with
|
|
* interrupts disabled.
|
|
*/
|
|
serial8250_rpm_get(up);
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
|
|
up->lcr = cval; /* Save computed LCR */
|
|
|
|
if (up->capabilities & UART_CAP_FIFO && port->fifosize > 1) {
|
|
/* NOTE: If fifo_bug is not set, a user can set RX_trigger. */
|
|
if ((baud < 2400 && !up->dma) || up->fifo_bug) {
|
|
up->fcr &= ~UART_FCR_TRIGGER_MASK;
|
|
up->fcr |= UART_FCR_TRIGGER_1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* MCR-based auto flow control. When AFE is enabled, RTS will be
|
|
* deasserted when the receive FIFO contains more characters than
|
|
* the trigger, or the MCR RTS bit is cleared.
|
|
*/
|
|
if (up->capabilities & UART_CAP_AFE) {
|
|
up->mcr &= ~UART_MCR_AFE;
|
|
if (termios->c_cflag & CRTSCTS)
|
|
up->mcr |= UART_MCR_AFE;
|
|
}
|
|
|
|
/*
|
|
* Update the per-port timeout.
|
|
*/
|
|
uart_update_timeout(port, termios->c_cflag, baud);
|
|
|
|
port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
|
|
if (termios->c_iflag & INPCK)
|
|
port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
|
|
if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
|
|
port->read_status_mask |= UART_LSR_BI;
|
|
|
|
/*
|
|
* Characteres to ignore
|
|
*/
|
|
port->ignore_status_mask = 0;
|
|
if (termios->c_iflag & IGNPAR)
|
|
port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
|
|
if (termios->c_iflag & IGNBRK) {
|
|
port->ignore_status_mask |= UART_LSR_BI;
|
|
/*
|
|
* If we're ignoring parity and break indicators,
|
|
* ignore overruns too (for real raw support).
|
|
*/
|
|
if (termios->c_iflag & IGNPAR)
|
|
port->ignore_status_mask |= UART_LSR_OE;
|
|
}
|
|
|
|
/*
|
|
* ignore all characters if CREAD is not set
|
|
*/
|
|
if ((termios->c_cflag & CREAD) == 0)
|
|
port->ignore_status_mask |= UART_LSR_DR;
|
|
|
|
/*
|
|
* CTS flow control flag and modem status interrupts
|
|
*/
|
|
up->ier &= ~UART_IER_MSI;
|
|
if (!(up->bugs & UART_BUG_NOMSR) &&
|
|
UART_ENABLE_MS(&up->port, termios->c_cflag))
|
|
up->ier |= UART_IER_MSI;
|
|
if (up->capabilities & UART_CAP_UUE)
|
|
up->ier |= UART_IER_UUE;
|
|
if (up->capabilities & UART_CAP_RTOIE)
|
|
up->ier |= UART_IER_RTOIE;
|
|
|
|
serial_port_out(port, UART_IER, up->ier);
|
|
|
|
if (up->capabilities & UART_CAP_EFR) {
|
|
unsigned char efr = 0;
|
|
/*
|
|
* TI16C752/Startech hardware flow control. FIXME:
|
|
* - TI16C752 requires control thresholds to be set.
|
|
* - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
|
|
*/
|
|
if (termios->c_cflag & CRTSCTS)
|
|
efr |= UART_EFR_CTS;
|
|
|
|
serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
|
|
if (port->flags & UPF_EXAR_EFR)
|
|
serial_port_out(port, UART_XR_EFR, efr);
|
|
else
|
|
serial_port_out(port, UART_EFR, efr);
|
|
}
|
|
|
|
serial8250_set_divisor(port, baud, quot, frac);
|
|
|
|
/*
|
|
* LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
|
|
* is written without DLAB set, this mode will be disabled.
|
|
*/
|
|
if (port->type == PORT_16750)
|
|
serial_port_out(port, UART_FCR, up->fcr);
|
|
|
|
serial_port_out(port, UART_LCR, up->lcr); /* reset DLAB */
|
|
if (port->type != PORT_16750) {
|
|
/* emulated UARTs (Lucent Venus 167x) need two steps */
|
|
if (up->fcr & UART_FCR_ENABLE_FIFO)
|
|
serial_port_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
|
|
serial_port_out(port, UART_FCR, up->fcr); /* set fcr */
|
|
}
|
|
serial8250_set_mctrl(port, port->mctrl);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
serial8250_rpm_put(up);
|
|
|
|
/* Don't rewrite B0 */
|
|
if (tty_termios_baud_rate(termios))
|
|
tty_termios_encode_baud_rate(termios, baud, baud);
|
|
}
|
|
EXPORT_SYMBOL(serial8250_do_set_termios);
|
|
|
|
static void
|
|
serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
|
|
struct ktermios *old)
|
|
{
|
|
if (port->set_termios)
|
|
port->set_termios(port, termios, old);
|
|
else
|
|
serial8250_do_set_termios(port, termios, old);
|
|
}
|
|
|
|
void serial8250_do_set_ldisc(struct uart_port *port, struct ktermios *termios)
|
|
{
|
|
if (termios->c_line == N_PPS) {
|
|
port->flags |= UPF_HARDPPS_CD;
|
|
spin_lock_irq(&port->lock);
|
|
serial8250_enable_ms(port);
|
|
spin_unlock_irq(&port->lock);
|
|
} else {
|
|
port->flags &= ~UPF_HARDPPS_CD;
|
|
if (!UART_ENABLE_MS(port, termios->c_cflag)) {
|
|
spin_lock_irq(&port->lock);
|
|
serial8250_disable_ms(port);
|
|
spin_unlock_irq(&port->lock);
|
|
}
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_do_set_ldisc);
|
|
|
|
static void
|
|
serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios)
|
|
{
|
|
if (port->set_ldisc)
|
|
port->set_ldisc(port, termios);
|
|
else
|
|
serial8250_do_set_ldisc(port, termios);
|
|
}
|
|
|
|
void serial8250_do_pm(struct uart_port *port, unsigned int state,
|
|
unsigned int oldstate)
|
|
{
|
|
struct uart_8250_port *p = up_to_u8250p(port);
|
|
|
|
serial8250_set_sleep(p, state != 0);
|
|
}
|
|
EXPORT_SYMBOL(serial8250_do_pm);
|
|
|
|
static void
|
|
serial8250_pm(struct uart_port *port, unsigned int state,
|
|
unsigned int oldstate)
|
|
{
|
|
if (port->pm)
|
|
port->pm(port, state, oldstate);
|
|
else
|
|
serial8250_do_pm(port, state, oldstate);
|
|
}
|
|
|
|
static unsigned int serial8250_port_size(struct uart_8250_port *pt)
|
|
{
|
|
if (pt->port.mapsize)
|
|
return pt->port.mapsize;
|
|
if (pt->port.iotype == UPIO_AU) {
|
|
if (pt->port.type == PORT_RT2880)
|
|
return 0x100;
|
|
return 0x1000;
|
|
}
|
|
if (is_omap1_8250(pt))
|
|
return 0x16 << pt->port.regshift;
|
|
|
|
return 8 << pt->port.regshift;
|
|
}
|
|
|
|
/*
|
|
* Resource handling.
|
|
*/
|
|
static int serial8250_request_std_resource(struct uart_8250_port *up)
|
|
{
|
|
unsigned int size = serial8250_port_size(up);
|
|
struct uart_port *port = &up->port;
|
|
int ret = 0;
|
|
|
|
switch (port->iotype) {
|
|
case UPIO_AU:
|
|
case UPIO_TSI:
|
|
case UPIO_MEM32:
|
|
case UPIO_MEM32BE:
|
|
case UPIO_MEM16:
|
|
case UPIO_MEM:
|
|
if (!port->mapbase)
|
|
break;
|
|
|
|
if (!request_mem_region(port->mapbase, size, "serial")) {
|
|
ret = -EBUSY;
|
|
break;
|
|
}
|
|
|
|
if (port->flags & UPF_IOREMAP) {
|
|
port->membase = ioremap(port->mapbase, size);
|
|
if (!port->membase) {
|
|
release_mem_region(port->mapbase, size);
|
|
ret = -ENOMEM;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case UPIO_HUB6:
|
|
case UPIO_PORT:
|
|
if (!request_region(port->iobase, size, "serial"))
|
|
ret = -EBUSY;
|
|
break;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void serial8250_release_std_resource(struct uart_8250_port *up)
|
|
{
|
|
unsigned int size = serial8250_port_size(up);
|
|
struct uart_port *port = &up->port;
|
|
|
|
switch (port->iotype) {
|
|
case UPIO_AU:
|
|
case UPIO_TSI:
|
|
case UPIO_MEM32:
|
|
case UPIO_MEM32BE:
|
|
case UPIO_MEM16:
|
|
case UPIO_MEM:
|
|
if (!port->mapbase)
|
|
break;
|
|
|
|
if (port->flags & UPF_IOREMAP) {
|
|
iounmap(port->membase);
|
|
port->membase = NULL;
|
|
}
|
|
|
|
release_mem_region(port->mapbase, size);
|
|
break;
|
|
|
|
case UPIO_HUB6:
|
|
case UPIO_PORT:
|
|
release_region(port->iobase, size);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void serial8250_release_port(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
serial8250_release_std_resource(up);
|
|
}
|
|
|
|
static int serial8250_request_port(struct uart_port *port)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
return serial8250_request_std_resource(up);
|
|
}
|
|
|
|
static int fcr_get_rxtrig_bytes(struct uart_8250_port *up)
|
|
{
|
|
const struct serial8250_config *conf_type = &uart_config[up->port.type];
|
|
unsigned char bytes;
|
|
|
|
bytes = conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(up->fcr)];
|
|
|
|
return bytes ? bytes : -EOPNOTSUPP;
|
|
}
|
|
|
|
static int bytes_to_fcr_rxtrig(struct uart_8250_port *up, unsigned char bytes)
|
|
{
|
|
const struct serial8250_config *conf_type = &uart_config[up->port.type];
|
|
int i;
|
|
|
|
if (!conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(UART_FCR_R_TRIG_00)])
|
|
return -EOPNOTSUPP;
|
|
|
|
for (i = 1; i < UART_FCR_R_TRIG_MAX_STATE; i++) {
|
|
if (bytes < conf_type->rxtrig_bytes[i])
|
|
/* Use the nearest lower value */
|
|
return (--i) << UART_FCR_R_TRIG_SHIFT;
|
|
}
|
|
|
|
return UART_FCR_R_TRIG_11;
|
|
}
|
|
|
|
static int do_get_rxtrig(struct tty_port *port)
|
|
{
|
|
struct uart_state *state = container_of(port, struct uart_state, port);
|
|
struct uart_port *uport = state->uart_port;
|
|
struct uart_8250_port *up = up_to_u8250p(uport);
|
|
|
|
if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1)
|
|
return -EINVAL;
|
|
|
|
return fcr_get_rxtrig_bytes(up);
|
|
}
|
|
|
|
static int do_serial8250_get_rxtrig(struct tty_port *port)
|
|
{
|
|
int rxtrig_bytes;
|
|
|
|
mutex_lock(&port->mutex);
|
|
rxtrig_bytes = do_get_rxtrig(port);
|
|
mutex_unlock(&port->mutex);
|
|
|
|
return rxtrig_bytes;
|
|
}
|
|
|
|
static ssize_t rx_trig_bytes_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct tty_port *port = dev_get_drvdata(dev);
|
|
int rxtrig_bytes;
|
|
|
|
rxtrig_bytes = do_serial8250_get_rxtrig(port);
|
|
if (rxtrig_bytes < 0)
|
|
return rxtrig_bytes;
|
|
|
|
return snprintf(buf, PAGE_SIZE, "%d\n", rxtrig_bytes);
|
|
}
|
|
|
|
static int do_set_rxtrig(struct tty_port *port, unsigned char bytes)
|
|
{
|
|
struct uart_state *state = container_of(port, struct uart_state, port);
|
|
struct uart_port *uport = state->uart_port;
|
|
struct uart_8250_port *up = up_to_u8250p(uport);
|
|
int rxtrig;
|
|
|
|
if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1 ||
|
|
up->fifo_bug)
|
|
return -EINVAL;
|
|
|
|
rxtrig = bytes_to_fcr_rxtrig(up, bytes);
|
|
if (rxtrig < 0)
|
|
return rxtrig;
|
|
|
|
serial8250_clear_fifos(up);
|
|
up->fcr &= ~UART_FCR_TRIGGER_MASK;
|
|
up->fcr |= (unsigned char)rxtrig;
|
|
serial_out(up, UART_FCR, up->fcr);
|
|
return 0;
|
|
}
|
|
|
|
static int do_serial8250_set_rxtrig(struct tty_port *port, unsigned char bytes)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&port->mutex);
|
|
ret = do_set_rxtrig(port, bytes);
|
|
mutex_unlock(&port->mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t rx_trig_bytes_store(struct device *dev,
|
|
struct device_attribute *attr, const char *buf, size_t count)
|
|
{
|
|
struct tty_port *port = dev_get_drvdata(dev);
|
|
unsigned char bytes;
|
|
int ret;
|
|
|
|
if (!count)
|
|
return -EINVAL;
|
|
|
|
ret = kstrtou8(buf, 10, &bytes);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = do_serial8250_set_rxtrig(port, bytes);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return count;
|
|
}
|
|
|
|
static DEVICE_ATTR_RW(rx_trig_bytes);
|
|
|
|
static struct attribute *serial8250_dev_attrs[] = {
|
|
&dev_attr_rx_trig_bytes.attr,
|
|
NULL
|
|
};
|
|
|
|
static struct attribute_group serial8250_dev_attr_group = {
|
|
.attrs = serial8250_dev_attrs,
|
|
};
|
|
|
|
static void register_dev_spec_attr_grp(struct uart_8250_port *up)
|
|
{
|
|
const struct serial8250_config *conf_type = &uart_config[up->port.type];
|
|
|
|
if (conf_type->rxtrig_bytes[0])
|
|
up->port.attr_group = &serial8250_dev_attr_group;
|
|
}
|
|
|
|
static void serial8250_config_port(struct uart_port *port, int flags)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
int ret;
|
|
|
|
/*
|
|
* Find the region that we can probe for. This in turn
|
|
* tells us whether we can probe for the type of port.
|
|
*/
|
|
ret = serial8250_request_std_resource(up);
|
|
if (ret < 0)
|
|
return;
|
|
|
|
if (port->iotype != up->cur_iotype)
|
|
set_io_from_upio(port);
|
|
|
|
if (flags & UART_CONFIG_TYPE)
|
|
autoconfig(up);
|
|
|
|
if (port->rs485.flags & SER_RS485_ENABLED)
|
|
port->rs485_config(port, &port->rs485);
|
|
|
|
/* if access method is AU, it is a 16550 with a quirk */
|
|
if (port->type == PORT_16550A && port->iotype == UPIO_AU)
|
|
up->bugs |= UART_BUG_NOMSR;
|
|
|
|
/* HW bugs may trigger IRQ while IIR == NO_INT */
|
|
if (port->type == PORT_TEGRA)
|
|
up->bugs |= UART_BUG_NOMSR;
|
|
|
|
if (port->type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
|
|
autoconfig_irq(up);
|
|
|
|
if (port->type == PORT_UNKNOWN)
|
|
serial8250_release_std_resource(up);
|
|
|
|
register_dev_spec_attr_grp(up);
|
|
up->fcr = uart_config[up->port.type].fcr;
|
|
}
|
|
|
|
static int
|
|
serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
|
|
{
|
|
if (ser->irq >= nr_irqs || ser->irq < 0 ||
|
|
ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
|
|
ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
|
|
ser->type == PORT_STARTECH)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
static const char *serial8250_type(struct uart_port *port)
|
|
{
|
|
int type = port->type;
|
|
|
|
if (type >= ARRAY_SIZE(uart_config))
|
|
type = 0;
|
|
return uart_config[type].name;
|
|
}
|
|
|
|
static const struct uart_ops serial8250_pops = {
|
|
.tx_empty = serial8250_tx_empty,
|
|
.set_mctrl = serial8250_set_mctrl,
|
|
.get_mctrl = serial8250_get_mctrl,
|
|
.stop_tx = serial8250_stop_tx,
|
|
.start_tx = serial8250_start_tx,
|
|
.throttle = serial8250_throttle,
|
|
.unthrottle = serial8250_unthrottle,
|
|
.stop_rx = serial8250_stop_rx,
|
|
.enable_ms = serial8250_enable_ms,
|
|
.break_ctl = serial8250_break_ctl,
|
|
.startup = serial8250_startup,
|
|
.shutdown = serial8250_shutdown,
|
|
.set_termios = serial8250_set_termios,
|
|
.set_ldisc = serial8250_set_ldisc,
|
|
.pm = serial8250_pm,
|
|
.type = serial8250_type,
|
|
.release_port = serial8250_release_port,
|
|
.request_port = serial8250_request_port,
|
|
.config_port = serial8250_config_port,
|
|
.verify_port = serial8250_verify_port,
|
|
#ifdef CONFIG_CONSOLE_POLL
|
|
.poll_get_char = serial8250_get_poll_char,
|
|
.poll_put_char = serial8250_put_poll_char,
|
|
#endif
|
|
};
|
|
|
|
void serial8250_init_port(struct uart_8250_port *up)
|
|
{
|
|
struct uart_port *port = &up->port;
|
|
|
|
spin_lock_init(&port->lock);
|
|
port->ops = &serial8250_pops;
|
|
port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
|
|
|
|
up->cur_iotype = 0xFF;
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_init_port);
|
|
|
|
void serial8250_set_defaults(struct uart_8250_port *up)
|
|
{
|
|
struct uart_port *port = &up->port;
|
|
|
|
if (up->port.flags & UPF_FIXED_TYPE) {
|
|
unsigned int type = up->port.type;
|
|
|
|
if (!up->port.fifosize)
|
|
up->port.fifosize = uart_config[type].fifo_size;
|
|
if (!up->tx_loadsz)
|
|
up->tx_loadsz = uart_config[type].tx_loadsz;
|
|
if (!up->capabilities)
|
|
up->capabilities = uart_config[type].flags;
|
|
}
|
|
|
|
set_io_from_upio(port);
|
|
|
|
/* default dma handlers */
|
|
if (up->dma) {
|
|
if (!up->dma->tx_dma)
|
|
up->dma->tx_dma = serial8250_tx_dma;
|
|
if (!up->dma->rx_dma)
|
|
up->dma->rx_dma = serial8250_rx_dma;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(serial8250_set_defaults);
|
|
|
|
#ifdef CONFIG_SERIAL_8250_CONSOLE
|
|
|
|
static void serial8250_console_putchar(struct uart_port *port, int ch)
|
|
{
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
wait_for_xmitr(up, UART_LSR_THRE);
|
|
serial_port_out(port, UART_TX, ch);
|
|
}
|
|
|
|
/*
|
|
* Restore serial console when h/w power-off detected
|
|
*/
|
|
static void serial8250_console_restore(struct uart_8250_port *up)
|
|
{
|
|
struct uart_port *port = &up->port;
|
|
struct ktermios termios;
|
|
unsigned int baud, quot, frac = 0;
|
|
|
|
termios.c_cflag = port->cons->cflag;
|
|
if (port->state->port.tty && termios.c_cflag == 0)
|
|
termios.c_cflag = port->state->port.tty->termios.c_cflag;
|
|
|
|
baud = serial8250_get_baud_rate(port, &termios, NULL);
|
|
quot = serial8250_get_divisor(port, baud, &frac);
|
|
|
|
serial8250_set_divisor(port, baud, quot, frac);
|
|
serial_port_out(port, UART_LCR, up->lcr);
|
|
serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS);
|
|
}
|
|
|
|
/*
|
|
* Print a string to the serial port trying not to disturb
|
|
* any possible real use of the port...
|
|
*
|
|
* The console_lock must be held when we get here.
|
|
*
|
|
* Doing runtime PM is really a bad idea for the kernel console.
|
|
* Thus, we assume the function is called when device is powered up.
|
|
*/
|
|
void serial8250_console_write(struct uart_8250_port *up, const char *s,
|
|
unsigned int count)
|
|
{
|
|
struct uart_8250_em485 *em485 = up->em485;
|
|
struct uart_port *port = &up->port;
|
|
unsigned long flags;
|
|
unsigned int ier;
|
|
int locked = 1;
|
|
|
|
touch_nmi_watchdog();
|
|
|
|
if (oops_in_progress)
|
|
locked = spin_trylock_irqsave(&port->lock, flags);
|
|
else
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
|
|
/*
|
|
* First save the IER then disable the interrupts
|
|
*/
|
|
ier = serial_port_in(port, UART_IER);
|
|
|
|
if (up->capabilities & UART_CAP_UUE)
|
|
serial_port_out(port, UART_IER, UART_IER_UUE);
|
|
else
|
|
serial_port_out(port, UART_IER, 0);
|
|
|
|
/* check scratch reg to see if port powered off during system sleep */
|
|
if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) {
|
|
serial8250_console_restore(up);
|
|
up->canary = 0;
|
|
}
|
|
|
|
if (em485) {
|
|
if (em485->tx_stopped)
|
|
up->rs485_start_tx(up);
|
|
mdelay(port->rs485.delay_rts_before_send);
|
|
}
|
|
|
|
uart_console_write(port, s, count, serial8250_console_putchar);
|
|
|
|
/*
|
|
* Finally, wait for transmitter to become empty
|
|
* and restore the IER
|
|
*/
|
|
wait_for_xmitr(up, BOTH_EMPTY);
|
|
|
|
if (em485) {
|
|
mdelay(port->rs485.delay_rts_after_send);
|
|
if (em485->tx_stopped)
|
|
up->rs485_stop_tx(up);
|
|
}
|
|
|
|
serial_port_out(port, UART_IER, ier);
|
|
|
|
/*
|
|
* The receive handling will happen properly because the
|
|
* receive ready bit will still be set; it is not cleared
|
|
* on read. However, modem control will not, we must
|
|
* call it if we have saved something in the saved flags
|
|
* while processing with interrupts off.
|
|
*/
|
|
if (up->msr_saved_flags)
|
|
serial8250_modem_status(up);
|
|
|
|
if (locked)
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
|
|
static unsigned int probe_baud(struct uart_port *port)
|
|
{
|
|
unsigned char lcr, dll, dlm;
|
|
unsigned int quot;
|
|
|
|
lcr = serial_port_in(port, UART_LCR);
|
|
serial_port_out(port, UART_LCR, lcr | UART_LCR_DLAB);
|
|
dll = serial_port_in(port, UART_DLL);
|
|
dlm = serial_port_in(port, UART_DLM);
|
|
serial_port_out(port, UART_LCR, lcr);
|
|
|
|
quot = (dlm << 8) | dll;
|
|
return (port->uartclk / 16) / quot;
|
|
}
|
|
|
|
int serial8250_console_setup(struct uart_port *port, char *options, bool probe)
|
|
{
|
|
int baud = 9600;
|
|
int bits = 8;
|
|
int parity = 'n';
|
|
int flow = 'n';
|
|
int ret;
|
|
|
|
if (!port->iobase && !port->membase)
|
|
return -ENODEV;
|
|
|
|
if (options)
|
|
uart_parse_options(options, &baud, &parity, &bits, &flow);
|
|
else if (probe)
|
|
baud = probe_baud(port);
|
|
|
|
ret = uart_set_options(port, port->cons, baud, parity, bits, flow);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (port->dev)
|
|
pm_runtime_get_sync(port->dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int serial8250_console_exit(struct uart_port *port)
|
|
{
|
|
if (port->dev)
|
|
pm_runtime_put_sync(port->dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif /* CONFIG_SERIAL_8250_CONSOLE */
|
|
|
|
MODULE_LICENSE("GPL");
|