mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 09:19:51 +00:00
![Sudeep Holla](/assets/img/avatar_default.png)
These drivers doesn't claim the serial device to be wakeup source. Even if it is, it needs to use enable_irq_wake or other related PM wakeup APIs to enable it. This patch removes yet another misuse of IRQF_NO_SUSPEND. Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com> Cc: Maxime Coquelin <maxime.coquelin@st.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-arm-kernel@lists.infradead.org Cc: kernel@stlinux.com Cc: linux-serial@vger.kernel.org Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
738 lines
17 KiB
C
738 lines
17 KiB
C
/*
|
|
* Copyright (C) Maxime Coquelin 2015
|
|
* Author: Maxime Coquelin <mcoquelin.stm32@gmail.com>
|
|
* License terms: GNU General Public License (GPL), version 2
|
|
*
|
|
* Inspired by st-asc.c from STMicroelectronics (c)
|
|
*/
|
|
|
|
#if defined(CONFIG_SERIAL_STM32_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
|
|
#define SUPPORT_SYSRQ
|
|
#endif
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/serial.h>
|
|
#include <linux/console.h>
|
|
#include <linux/sysrq.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/io.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/tty_flip.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/pm_runtime.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_platform.h>
|
|
#include <linux/serial_core.h>
|
|
#include <linux/clk.h>
|
|
|
|
#define DRIVER_NAME "stm32-usart"
|
|
|
|
/* Register offsets */
|
|
#define USART_SR 0x00
|
|
#define USART_DR 0x04
|
|
#define USART_BRR 0x08
|
|
#define USART_CR1 0x0c
|
|
#define USART_CR2 0x10
|
|
#define USART_CR3 0x14
|
|
#define USART_GTPR 0x18
|
|
|
|
/* USART_SR */
|
|
#define USART_SR_PE BIT(0)
|
|
#define USART_SR_FE BIT(1)
|
|
#define USART_SR_NF BIT(2)
|
|
#define USART_SR_ORE BIT(3)
|
|
#define USART_SR_IDLE BIT(4)
|
|
#define USART_SR_RXNE BIT(5)
|
|
#define USART_SR_TC BIT(6)
|
|
#define USART_SR_TXE BIT(7)
|
|
#define USART_SR_LBD BIT(8)
|
|
#define USART_SR_CTS BIT(9)
|
|
#define USART_SR_ERR_MASK (USART_SR_LBD | USART_SR_ORE | \
|
|
USART_SR_FE | USART_SR_PE)
|
|
/* Dummy bits */
|
|
#define USART_SR_DUMMY_RX BIT(16)
|
|
|
|
/* USART_DR */
|
|
#define USART_DR_MASK GENMASK(8, 0)
|
|
|
|
/* USART_BRR */
|
|
#define USART_BRR_DIV_F_MASK GENMASK(3, 0)
|
|
#define USART_BRR_DIV_M_MASK GENMASK(15, 4)
|
|
#define USART_BRR_DIV_M_SHIFT 4
|
|
|
|
/* USART_CR1 */
|
|
#define USART_CR1_SBK BIT(0)
|
|
#define USART_CR1_RWU BIT(1)
|
|
#define USART_CR1_RE BIT(2)
|
|
#define USART_CR1_TE BIT(3)
|
|
#define USART_CR1_IDLEIE BIT(4)
|
|
#define USART_CR1_RXNEIE BIT(5)
|
|
#define USART_CR1_TCIE BIT(6)
|
|
#define USART_CR1_TXEIE BIT(7)
|
|
#define USART_CR1_PEIE BIT(8)
|
|
#define USART_CR1_PS BIT(9)
|
|
#define USART_CR1_PCE BIT(10)
|
|
#define USART_CR1_WAKE BIT(11)
|
|
#define USART_CR1_M BIT(12)
|
|
#define USART_CR1_UE BIT(13)
|
|
#define USART_CR1_OVER8 BIT(15)
|
|
#define USART_CR1_IE_MASK GENMASK(8, 4)
|
|
|
|
/* USART_CR2 */
|
|
#define USART_CR2_ADD_MASK GENMASK(3, 0)
|
|
#define USART_CR2_LBDL BIT(5)
|
|
#define USART_CR2_LBDIE BIT(6)
|
|
#define USART_CR2_LBCL BIT(8)
|
|
#define USART_CR2_CPHA BIT(9)
|
|
#define USART_CR2_CPOL BIT(10)
|
|
#define USART_CR2_CLKEN BIT(11)
|
|
#define USART_CR2_STOP_2B BIT(13)
|
|
#define USART_CR2_STOP_MASK GENMASK(13, 12)
|
|
#define USART_CR2_LINEN BIT(14)
|
|
|
|
/* USART_CR3 */
|
|
#define USART_CR3_EIE BIT(0)
|
|
#define USART_CR3_IREN BIT(1)
|
|
#define USART_CR3_IRLP BIT(2)
|
|
#define USART_CR3_HDSEL BIT(3)
|
|
#define USART_CR3_NACK BIT(4)
|
|
#define USART_CR3_SCEN BIT(5)
|
|
#define USART_CR3_DMAR BIT(6)
|
|
#define USART_CR3_DMAT BIT(7)
|
|
#define USART_CR3_RTSE BIT(8)
|
|
#define USART_CR3_CTSE BIT(9)
|
|
#define USART_CR3_CTSIE BIT(10)
|
|
#define USART_CR3_ONEBIT BIT(11)
|
|
|
|
/* USART_GTPR */
|
|
#define USART_GTPR_PSC_MASK GENMASK(7, 0)
|
|
#define USART_GTPR_GT_MASK GENMASK(15, 8)
|
|
|
|
#define DRIVER_NAME "stm32-usart"
|
|
#define STM32_SERIAL_NAME "ttyS"
|
|
#define STM32_MAX_PORTS 6
|
|
|
|
struct stm32_port {
|
|
struct uart_port port;
|
|
struct clk *clk;
|
|
bool hw_flow_control;
|
|
};
|
|
|
|
static struct stm32_port stm32_ports[STM32_MAX_PORTS];
|
|
static struct uart_driver stm32_usart_driver;
|
|
|
|
static void stm32_stop_tx(struct uart_port *port);
|
|
|
|
static inline struct stm32_port *to_stm32_port(struct uart_port *port)
|
|
{
|
|
return container_of(port, struct stm32_port, port);
|
|
}
|
|
|
|
static void stm32_set_bits(struct uart_port *port, u32 reg, u32 bits)
|
|
{
|
|
u32 val;
|
|
|
|
val = readl_relaxed(port->membase + reg);
|
|
val |= bits;
|
|
writel_relaxed(val, port->membase + reg);
|
|
}
|
|
|
|
static void stm32_clr_bits(struct uart_port *port, u32 reg, u32 bits)
|
|
{
|
|
u32 val;
|
|
|
|
val = readl_relaxed(port->membase + reg);
|
|
val &= ~bits;
|
|
writel_relaxed(val, port->membase + reg);
|
|
}
|
|
|
|
static void stm32_receive_chars(struct uart_port *port)
|
|
{
|
|
struct tty_port *tport = &port->state->port;
|
|
unsigned long c;
|
|
u32 sr;
|
|
char flag;
|
|
|
|
if (port->irq_wake)
|
|
pm_wakeup_event(tport->tty->dev, 0);
|
|
|
|
while ((sr = readl_relaxed(port->membase + USART_SR)) & USART_SR_RXNE) {
|
|
sr |= USART_SR_DUMMY_RX;
|
|
c = readl_relaxed(port->membase + USART_DR);
|
|
flag = TTY_NORMAL;
|
|
port->icount.rx++;
|
|
|
|
if (sr & USART_SR_ERR_MASK) {
|
|
if (sr & USART_SR_LBD) {
|
|
port->icount.brk++;
|
|
if (uart_handle_break(port))
|
|
continue;
|
|
} else if (sr & USART_SR_ORE) {
|
|
port->icount.overrun++;
|
|
} else if (sr & USART_SR_PE) {
|
|
port->icount.parity++;
|
|
} else if (sr & USART_SR_FE) {
|
|
port->icount.frame++;
|
|
}
|
|
|
|
sr &= port->read_status_mask;
|
|
|
|
if (sr & USART_SR_LBD)
|
|
flag = TTY_BREAK;
|
|
else if (sr & USART_SR_PE)
|
|
flag = TTY_PARITY;
|
|
else if (sr & USART_SR_FE)
|
|
flag = TTY_FRAME;
|
|
}
|
|
|
|
if (uart_handle_sysrq_char(port, c))
|
|
continue;
|
|
uart_insert_char(port, sr, USART_SR_ORE, c, flag);
|
|
}
|
|
|
|
spin_unlock(&port->lock);
|
|
tty_flip_buffer_push(tport);
|
|
spin_lock(&port->lock);
|
|
}
|
|
|
|
static void stm32_transmit_chars(struct uart_port *port)
|
|
{
|
|
struct circ_buf *xmit = &port->state->xmit;
|
|
|
|
if (port->x_char) {
|
|
writel_relaxed(port->x_char, port->membase + USART_DR);
|
|
port->x_char = 0;
|
|
port->icount.tx++;
|
|
return;
|
|
}
|
|
|
|
if (uart_tx_stopped(port)) {
|
|
stm32_stop_tx(port);
|
|
return;
|
|
}
|
|
|
|
if (uart_circ_empty(xmit)) {
|
|
stm32_stop_tx(port);
|
|
return;
|
|
}
|
|
|
|
writel_relaxed(xmit->buf[xmit->tail], port->membase + USART_DR);
|
|
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
|
|
port->icount.tx++;
|
|
|
|
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
|
|
uart_write_wakeup(port);
|
|
|
|
if (uart_circ_empty(xmit))
|
|
stm32_stop_tx(port);
|
|
}
|
|
|
|
static irqreturn_t stm32_interrupt(int irq, void *ptr)
|
|
{
|
|
struct uart_port *port = ptr;
|
|
u32 sr;
|
|
|
|
spin_lock(&port->lock);
|
|
|
|
sr = readl_relaxed(port->membase + USART_SR);
|
|
|
|
if (sr & USART_SR_RXNE)
|
|
stm32_receive_chars(port);
|
|
|
|
if (sr & USART_SR_TXE)
|
|
stm32_transmit_chars(port);
|
|
|
|
spin_unlock(&port->lock);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static unsigned int stm32_tx_empty(struct uart_port *port)
|
|
{
|
|
return readl_relaxed(port->membase + USART_SR) & USART_SR_TXE;
|
|
}
|
|
|
|
static void stm32_set_mctrl(struct uart_port *port, unsigned int mctrl)
|
|
{
|
|
if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
|
|
stm32_set_bits(port, USART_CR3, USART_CR3_RTSE);
|
|
else
|
|
stm32_clr_bits(port, USART_CR3, USART_CR3_RTSE);
|
|
}
|
|
|
|
static unsigned int stm32_get_mctrl(struct uart_port *port)
|
|
{
|
|
/* This routine is used to get signals of: DCD, DSR, RI, and CTS */
|
|
return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
|
|
}
|
|
|
|
/* Transmit stop */
|
|
static void stm32_stop_tx(struct uart_port *port)
|
|
{
|
|
stm32_clr_bits(port, USART_CR1, USART_CR1_TXEIE);
|
|
}
|
|
|
|
/* There are probably characters waiting to be transmitted. */
|
|
static void stm32_start_tx(struct uart_port *port)
|
|
{
|
|
struct circ_buf *xmit = &port->state->xmit;
|
|
|
|
if (uart_circ_empty(xmit))
|
|
return;
|
|
|
|
stm32_set_bits(port, USART_CR1, USART_CR1_TXEIE | USART_CR1_TE);
|
|
}
|
|
|
|
/* Throttle the remote when input buffer is about to overflow. */
|
|
static void stm32_throttle(struct uart_port *port)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
stm32_clr_bits(port, USART_CR1, USART_CR1_RXNEIE);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
|
|
/* Unthrottle the remote, the input buffer can now accept data. */
|
|
static void stm32_unthrottle(struct uart_port *port)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
stm32_set_bits(port, USART_CR1, USART_CR1_RXNEIE);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
|
|
/* Receive stop */
|
|
static void stm32_stop_rx(struct uart_port *port)
|
|
{
|
|
stm32_clr_bits(port, USART_CR1, USART_CR1_RXNEIE);
|
|
}
|
|
|
|
/* Handle breaks - ignored by us */
|
|
static void stm32_break_ctl(struct uart_port *port, int break_state)
|
|
{
|
|
}
|
|
|
|
static int stm32_startup(struct uart_port *port)
|
|
{
|
|
const char *name = to_platform_device(port->dev)->name;
|
|
u32 val;
|
|
int ret;
|
|
|
|
ret = request_irq(port->irq, stm32_interrupt, 0, name, port);
|
|
if (ret)
|
|
return ret;
|
|
|
|
val = USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE;
|
|
stm32_set_bits(port, USART_CR1, val);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void stm32_shutdown(struct uart_port *port)
|
|
{
|
|
u32 val;
|
|
|
|
val = USART_CR1_TXEIE | USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE;
|
|
stm32_set_bits(port, USART_CR1, val);
|
|
|
|
free_irq(port->irq, port);
|
|
}
|
|
|
|
static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
|
|
struct ktermios *old)
|
|
{
|
|
struct stm32_port *stm32_port = to_stm32_port(port);
|
|
unsigned int baud;
|
|
u32 usartdiv, mantissa, fraction, oversampling;
|
|
tcflag_t cflag = termios->c_cflag;
|
|
u32 cr1, cr2, cr3;
|
|
unsigned long flags;
|
|
|
|
if (!stm32_port->hw_flow_control)
|
|
cflag &= ~CRTSCTS;
|
|
|
|
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 8);
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
|
|
/* Stop serial port and reset value */
|
|
writel_relaxed(0, port->membase + USART_CR1);
|
|
|
|
cr1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_UE | USART_CR1_RXNEIE;
|
|
cr2 = 0;
|
|
cr3 = 0;
|
|
|
|
if (cflag & CSTOPB)
|
|
cr2 |= USART_CR2_STOP_2B;
|
|
|
|
if (cflag & PARENB) {
|
|
cr1 |= USART_CR1_PCE;
|
|
if ((cflag & CSIZE) == CS8)
|
|
cr1 |= USART_CR1_M;
|
|
}
|
|
|
|
if (cflag & PARODD)
|
|
cr1 |= USART_CR1_PS;
|
|
|
|
port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
|
|
if (cflag & CRTSCTS) {
|
|
port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
|
|
cr3 |= USART_CR3_CTSE;
|
|
}
|
|
|
|
usartdiv = DIV_ROUND_CLOSEST(port->uartclk, baud);
|
|
|
|
/*
|
|
* The USART supports 16 or 8 times oversampling.
|
|
* By default we prefer 16 times oversampling, so that the receiver
|
|
* has a better tolerance to clock deviations.
|
|
* 8 times oversampling is only used to achieve higher speeds.
|
|
*/
|
|
if (usartdiv < 16) {
|
|
oversampling = 8;
|
|
stm32_set_bits(port, USART_CR1, USART_CR1_OVER8);
|
|
} else {
|
|
oversampling = 16;
|
|
stm32_clr_bits(port, USART_CR1, USART_CR1_OVER8);
|
|
}
|
|
|
|
mantissa = (usartdiv / oversampling) << USART_BRR_DIV_M_SHIFT;
|
|
fraction = usartdiv % oversampling;
|
|
writel_relaxed(mantissa | fraction, port->membase + USART_BRR);
|
|
|
|
uart_update_timeout(port, cflag, baud);
|
|
|
|
port->read_status_mask = USART_SR_ORE;
|
|
if (termios->c_iflag & INPCK)
|
|
port->read_status_mask |= USART_SR_PE | USART_SR_FE;
|
|
if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
|
|
port->read_status_mask |= USART_SR_LBD;
|
|
|
|
/* Characters to ignore */
|
|
port->ignore_status_mask = 0;
|
|
if (termios->c_iflag & IGNPAR)
|
|
port->ignore_status_mask = USART_SR_PE | USART_SR_FE;
|
|
if (termios->c_iflag & IGNBRK) {
|
|
port->ignore_status_mask |= USART_SR_LBD;
|
|
/*
|
|
* If we're ignoring parity and break indicators,
|
|
* ignore overruns too (for real raw support).
|
|
*/
|
|
if (termios->c_iflag & IGNPAR)
|
|
port->ignore_status_mask |= USART_SR_ORE;
|
|
}
|
|
|
|
/* Ignore all characters if CREAD is not set */
|
|
if ((termios->c_cflag & CREAD) == 0)
|
|
port->ignore_status_mask |= USART_SR_DUMMY_RX;
|
|
|
|
writel_relaxed(cr3, port->membase + USART_CR3);
|
|
writel_relaxed(cr2, port->membase + USART_CR2);
|
|
writel_relaxed(cr1, port->membase + USART_CR1);
|
|
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
|
|
static const char *stm32_type(struct uart_port *port)
|
|
{
|
|
return (port->type == PORT_STM32) ? DRIVER_NAME : NULL;
|
|
}
|
|
|
|
static void stm32_release_port(struct uart_port *port)
|
|
{
|
|
}
|
|
|
|
static int stm32_request_port(struct uart_port *port)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void stm32_config_port(struct uart_port *port, int flags)
|
|
{
|
|
if (flags & UART_CONFIG_TYPE)
|
|
port->type = PORT_STM32;
|
|
}
|
|
|
|
static int
|
|
stm32_verify_port(struct uart_port *port, struct serial_struct *ser)
|
|
{
|
|
/* No user changeable parameters */
|
|
return -EINVAL;
|
|
}
|
|
|
|
static void stm32_pm(struct uart_port *port, unsigned int state,
|
|
unsigned int oldstate)
|
|
{
|
|
struct stm32_port *stm32port = container_of(port,
|
|
struct stm32_port, port);
|
|
unsigned long flags = 0;
|
|
|
|
switch (state) {
|
|
case UART_PM_STATE_ON:
|
|
clk_prepare_enable(stm32port->clk);
|
|
break;
|
|
case UART_PM_STATE_OFF:
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
stm32_clr_bits(port, USART_CR1, USART_CR1_UE);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
clk_disable_unprepare(stm32port->clk);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static const struct uart_ops stm32_uart_ops = {
|
|
.tx_empty = stm32_tx_empty,
|
|
.set_mctrl = stm32_set_mctrl,
|
|
.get_mctrl = stm32_get_mctrl,
|
|
.stop_tx = stm32_stop_tx,
|
|
.start_tx = stm32_start_tx,
|
|
.throttle = stm32_throttle,
|
|
.unthrottle = stm32_unthrottle,
|
|
.stop_rx = stm32_stop_rx,
|
|
.break_ctl = stm32_break_ctl,
|
|
.startup = stm32_startup,
|
|
.shutdown = stm32_shutdown,
|
|
.set_termios = stm32_set_termios,
|
|
.pm = stm32_pm,
|
|
.type = stm32_type,
|
|
.release_port = stm32_release_port,
|
|
.request_port = stm32_request_port,
|
|
.config_port = stm32_config_port,
|
|
.verify_port = stm32_verify_port,
|
|
};
|
|
|
|
static int stm32_init_port(struct stm32_port *stm32port,
|
|
struct platform_device *pdev)
|
|
{
|
|
struct uart_port *port = &stm32port->port;
|
|
struct resource *res;
|
|
int ret;
|
|
|
|
port->iotype = UPIO_MEM;
|
|
port->flags = UPF_BOOT_AUTOCONF;
|
|
port->ops = &stm32_uart_ops;
|
|
port->dev = &pdev->dev;
|
|
port->irq = platform_get_irq(pdev, 0);
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
port->membase = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(port->membase))
|
|
return PTR_ERR(port->membase);
|
|
port->mapbase = res->start;
|
|
|
|
spin_lock_init(&port->lock);
|
|
|
|
stm32port->clk = devm_clk_get(&pdev->dev, NULL);
|
|
if (IS_ERR(stm32port->clk))
|
|
return PTR_ERR(stm32port->clk);
|
|
|
|
/* Ensure that clk rate is correct by enabling the clk */
|
|
ret = clk_prepare_enable(stm32port->clk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
stm32port->port.uartclk = clk_get_rate(stm32port->clk);
|
|
if (!stm32port->port.uartclk)
|
|
ret = -EINVAL;
|
|
|
|
clk_disable_unprepare(stm32port->clk);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct stm32_port *stm32_of_get_stm32_port(struct platform_device *pdev)
|
|
{
|
|
struct device_node *np = pdev->dev.of_node;
|
|
int id;
|
|
|
|
if (!np)
|
|
return NULL;
|
|
|
|
id = of_alias_get_id(np, "serial");
|
|
if (id < 0)
|
|
id = 0;
|
|
|
|
if (WARN_ON(id >= STM32_MAX_PORTS))
|
|
return NULL;
|
|
|
|
stm32_ports[id].hw_flow_control = of_property_read_bool(np,
|
|
"auto-flow-control");
|
|
stm32_ports[id].port.line = id;
|
|
return &stm32_ports[id];
|
|
}
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id stm32_match[] = {
|
|
{ .compatible = "st,stm32-usart", },
|
|
{ .compatible = "st,stm32-uart", },
|
|
{},
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(of, stm32_match);
|
|
#endif
|
|
|
|
static int stm32_serial_probe(struct platform_device *pdev)
|
|
{
|
|
int ret;
|
|
struct stm32_port *stm32port;
|
|
|
|
stm32port = stm32_of_get_stm32_port(pdev);
|
|
if (!stm32port)
|
|
return -ENODEV;
|
|
|
|
ret = stm32_init_port(stm32port, pdev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = uart_add_one_port(&stm32_usart_driver, &stm32port->port);
|
|
if (ret)
|
|
return ret;
|
|
|
|
platform_set_drvdata(pdev, &stm32port->port);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_serial_remove(struct platform_device *pdev)
|
|
{
|
|
struct uart_port *port = platform_get_drvdata(pdev);
|
|
|
|
return uart_remove_one_port(&stm32_usart_driver, port);
|
|
}
|
|
|
|
|
|
#ifdef CONFIG_SERIAL_STM32_CONSOLE
|
|
static void stm32_console_putchar(struct uart_port *port, int ch)
|
|
{
|
|
while (!(readl_relaxed(port->membase + USART_SR) & USART_SR_TXE))
|
|
cpu_relax();
|
|
|
|
writel_relaxed(ch, port->membase + USART_DR);
|
|
}
|
|
|
|
static void stm32_console_write(struct console *co, const char *s, unsigned cnt)
|
|
{
|
|
struct uart_port *port = &stm32_ports[co->index].port;
|
|
unsigned long flags;
|
|
u32 old_cr1, new_cr1;
|
|
int locked = 1;
|
|
|
|
local_irq_save(flags);
|
|
if (port->sysrq)
|
|
locked = 0;
|
|
else if (oops_in_progress)
|
|
locked = spin_trylock(&port->lock);
|
|
else
|
|
spin_lock(&port->lock);
|
|
|
|
/* Save and disable interrupts */
|
|
old_cr1 = readl_relaxed(port->membase + USART_CR1);
|
|
new_cr1 = old_cr1 & ~USART_CR1_IE_MASK;
|
|
writel_relaxed(new_cr1, port->membase + USART_CR1);
|
|
|
|
uart_console_write(port, s, cnt, stm32_console_putchar);
|
|
|
|
/* Restore interrupt state */
|
|
writel_relaxed(old_cr1, port->membase + USART_CR1);
|
|
|
|
if (locked)
|
|
spin_unlock(&port->lock);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static int stm32_console_setup(struct console *co, char *options)
|
|
{
|
|
struct stm32_port *stm32port;
|
|
int baud = 9600;
|
|
int bits = 8;
|
|
int parity = 'n';
|
|
int flow = 'n';
|
|
|
|
if (co->index >= STM32_MAX_PORTS)
|
|
return -ENODEV;
|
|
|
|
stm32port = &stm32_ports[co->index];
|
|
|
|
/*
|
|
* This driver does not support early console initialization
|
|
* (use ARM early printk support instead), so we only expect
|
|
* this to be called during the uart port registration when the
|
|
* driver gets probed and the port should be mapped at that point.
|
|
*/
|
|
if (stm32port->port.mapbase == 0 || stm32port->port.membase == NULL)
|
|
return -ENXIO;
|
|
|
|
if (options)
|
|
uart_parse_options(options, &baud, &parity, &bits, &flow);
|
|
|
|
return uart_set_options(&stm32port->port, co, baud, parity, bits, flow);
|
|
}
|
|
|
|
static struct console stm32_console = {
|
|
.name = STM32_SERIAL_NAME,
|
|
.device = uart_console_device,
|
|
.write = stm32_console_write,
|
|
.setup = stm32_console_setup,
|
|
.flags = CON_PRINTBUFFER,
|
|
.index = -1,
|
|
.data = &stm32_usart_driver,
|
|
};
|
|
|
|
#define STM32_SERIAL_CONSOLE (&stm32_console)
|
|
|
|
#else
|
|
#define STM32_SERIAL_CONSOLE NULL
|
|
#endif /* CONFIG_SERIAL_STM32_CONSOLE */
|
|
|
|
static struct uart_driver stm32_usart_driver = {
|
|
.driver_name = DRIVER_NAME,
|
|
.dev_name = STM32_SERIAL_NAME,
|
|
.major = 0,
|
|
.minor = 0,
|
|
.nr = STM32_MAX_PORTS,
|
|
.cons = STM32_SERIAL_CONSOLE,
|
|
};
|
|
|
|
static struct platform_driver stm32_serial_driver = {
|
|
.probe = stm32_serial_probe,
|
|
.remove = stm32_serial_remove,
|
|
.driver = {
|
|
.name = DRIVER_NAME,
|
|
.of_match_table = of_match_ptr(stm32_match),
|
|
},
|
|
};
|
|
|
|
static int __init usart_init(void)
|
|
{
|
|
static char banner[] __initdata = "STM32 USART driver initialized";
|
|
int ret;
|
|
|
|
pr_info("%s\n", banner);
|
|
|
|
ret = uart_register_driver(&stm32_usart_driver);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = platform_driver_register(&stm32_serial_driver);
|
|
if (ret)
|
|
uart_unregister_driver(&stm32_usart_driver);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __exit usart_exit(void)
|
|
{
|
|
platform_driver_unregister(&stm32_serial_driver);
|
|
uart_unregister_driver(&stm32_usart_driver);
|
|
}
|
|
|
|
module_init(usart_init);
|
|
module_exit(usart_exit);
|
|
|
|
MODULE_ALIAS("platform:" DRIVER_NAME);
|
|
MODULE_DESCRIPTION("STMicroelectronics STM32 serial port driver");
|
|
MODULE_LICENSE("GPL v2");
|