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![Alan Cox](/assets/img/avatar_default.png)
The API and code have been through various bits of initial review by serial driver people but they definitely need to live somewhere for a while so the unconverted drivers can get knocked into shape, existing drivers that have been updated can be better tuned and bugs whacked out. This replaces the tty flip buffers with kmalloc objects in rings. In the normal situation for an IRQ driven serial port at typical speeds the behaviour is pretty much the same, two buffers end up allocated and the kernel cycles between them as before. When there are delays or at high speed we now behave far better as the buffer pool can grow a bit rather than lose characters. This also means that we can operate at higher speeds reliably. For drivers that receive characters in blocks (DMA based, USB and especially virtualisation) the layer allows a lot of driver specific code that works around the tty layer with private secondary queues to be removed. The IBM folks need this sort of layer, the smart serial port people do, the virtualisers do (because a virtualised tty typically operates at infinite speed rather than emulating 9600 baud). Finally many drivers had invalid and unsafe attempts to avoid buffer overflows by directly invoking tty methods extracted out of the innards of work queue structs. These are no longer needed and all go away. That fixes various random hangs with serial ports on overflow. The other change in here is to optimise the receive_room path that is used by some callers. It turns out that only one ldisc uses receive room except asa constant and it updates it far far less than the value is read. We thus make it a variable not a function call. I expect the code to contain bugs due to the size alone but I'll be watching and squashing them and feeding out new patches as it goes. Because the buffers now dynamically expand you should only run out of buffering when the kernel runs out of memory for real. That means a lot of the horrible hacks high performance drivers used to do just aren't needed any more. Description: tty_insert_flip_char is an old API and continues to work as before, as does tty_flip_buffer_push() [this is why many drivers dont need modification]. It does now also return the number of chars inserted There are also tty_buffer_request_room(tty, len) which asks for a buffer block of the length requested and returns the space found. This improves efficiency with hardware that knows how much to transfer. and tty_insert_flip_string_flags(tty, str, flags, len) to insert a string of characters and flags For a smart interface the usual code is len = tty_request_buffer_room(tty, amount_hardware_says); tty_insert_flip_string(tty, buffer_from_card, len); More description! At the moment tty buffers are attached directly to the tty. This is causing a lot of the problems related to tty layer locking, also problems at high speed and also with bursty data (such as occurs in virtualised environments) I'm working on ripping out the flip buffers and replacing them with a pool of dynamically allocated buffers. This allows both for old style "byte I/O" devices and also helps virtualisation and smart devices where large blocks of data suddenely materialise and need storing. So far so good. Lots of drivers reference tty->flip.*. Several of them also call directly and unsafely into function pointers it provides. This will all break. Most drivers can use tty_insert_flip_char which can be kept as an API but others need more. At the moment I've added the following interfaces, if people think more will be needed now is a good time to say int tty_buffer_request_room(tty, size) Try and ensure at least size bytes are available, returns actual room (may be zero). At the moment it just uses the flipbuf space but that will change. Repeated calls without characters being added are not cumulative. (ie if you call it with 1, 1, 1, and then 4 you'll have four characters of space. The other functions will also try and grow buffers in future but this will be a more efficient way when you know block sizes. int tty_insert_flip_char(tty, ch, flag) As before insert a character if there is room. Now returns 1 for success, 0 for failure. int tty_insert_flip_string(tty, str, len) Insert a block of non error characters. Returns the number inserted. int tty_prepare_flip_string(tty, strptr, len) Adjust the buffer to allow len characters to be added. Returns a buffer pointer in strptr and the length available. This allows for hardware that needs to use functions like insl or mencpy_fromio. Signed-off-by: Alan Cox <alan@redhat.com> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
843 lines
20 KiB
C
843 lines
20 KiB
C
/*
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* linux/drivers/char/amba.c
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*
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* Driver for AMBA serial ports
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*
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* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
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*
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* Copyright 1999 ARM Limited
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* Copyright (C) 2000 Deep Blue Solutions Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* $Id: amba.c,v 1.41 2002/07/28 10:03:27 rmk Exp $
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*
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* This is a generic driver for ARM AMBA-type serial ports. They
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* have a lot of 16550-like features, but are not register compatible.
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* Note that although they do have CTS, DCD and DSR inputs, they do
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* not have an RI input, nor do they have DTR or RTS outputs. If
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* required, these have to be supplied via some other means (eg, GPIO)
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* and hooked into this driver.
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*/
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#include <linux/config.h>
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#if defined(CONFIG_SERIAL_AMBA_PL011_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
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#define SUPPORT_SYSRQ
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#endif
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#include <linux/module.h>
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#include <linux/ioport.h>
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#include <linux/init.h>
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#include <linux/console.h>
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#include <linux/sysrq.h>
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#include <linux/device.h>
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#include <linux/tty.h>
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#include <linux/tty_flip.h>
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#include <linux/serial_core.h>
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#include <linux/serial.h>
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#include <linux/amba/bus.h>
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#include <linux/amba/serial.h>
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#include <linux/clk.h>
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#include <asm/io.h>
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#include <asm/sizes.h>
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#define UART_NR 14
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#define SERIAL_AMBA_MAJOR 204
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#define SERIAL_AMBA_MINOR 64
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#define SERIAL_AMBA_NR UART_NR
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#define AMBA_ISR_PASS_LIMIT 256
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#define UART_DR_ERROR (UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE)
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#define UART_DUMMY_DR_RX (1 << 16)
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/*
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* We wrap our port structure around the generic uart_port.
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*/
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struct uart_amba_port {
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struct uart_port port;
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struct clk *clk;
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unsigned int im; /* interrupt mask */
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unsigned int old_status;
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};
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static void pl011_stop_tx(struct uart_port *port)
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{
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struct uart_amba_port *uap = (struct uart_amba_port *)port;
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uap->im &= ~UART011_TXIM;
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writew(uap->im, uap->port.membase + UART011_IMSC);
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}
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static void pl011_start_tx(struct uart_port *port)
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{
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struct uart_amba_port *uap = (struct uart_amba_port *)port;
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uap->im |= UART011_TXIM;
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writew(uap->im, uap->port.membase + UART011_IMSC);
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}
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static void pl011_stop_rx(struct uart_port *port)
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{
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struct uart_amba_port *uap = (struct uart_amba_port *)port;
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uap->im &= ~(UART011_RXIM|UART011_RTIM|UART011_FEIM|
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UART011_PEIM|UART011_BEIM|UART011_OEIM);
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writew(uap->im, uap->port.membase + UART011_IMSC);
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}
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static void pl011_enable_ms(struct uart_port *port)
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{
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struct uart_amba_port *uap = (struct uart_amba_port *)port;
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uap->im |= UART011_RIMIM|UART011_CTSMIM|UART011_DCDMIM|UART011_DSRMIM;
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writew(uap->im, uap->port.membase + UART011_IMSC);
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}
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static void
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#ifdef SUPPORT_SYSRQ
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pl011_rx_chars(struct uart_amba_port *uap, struct pt_regs *regs)
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#else
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pl011_rx_chars(struct uart_amba_port *uap)
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#endif
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{
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struct tty_struct *tty = uap->port.info->tty;
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unsigned int status, ch, flag, max_count = 256;
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status = readw(uap->port.membase + UART01x_FR);
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while ((status & UART01x_FR_RXFE) == 0 && max_count--) {
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ch = readw(uap->port.membase + UART01x_DR) | UART_DUMMY_DR_RX;
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flag = TTY_NORMAL;
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uap->port.icount.rx++;
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/*
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* Note that the error handling code is
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* out of the main execution path
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*/
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if (unlikely(ch & UART_DR_ERROR)) {
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if (ch & UART011_DR_BE) {
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ch &= ~(UART011_DR_FE | UART011_DR_PE);
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uap->port.icount.brk++;
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if (uart_handle_break(&uap->port))
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goto ignore_char;
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} else if (ch & UART011_DR_PE)
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uap->port.icount.parity++;
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else if (ch & UART011_DR_FE)
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uap->port.icount.frame++;
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if (ch & UART011_DR_OE)
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uap->port.icount.overrun++;
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ch &= uap->port.read_status_mask;
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if (ch & UART011_DR_BE)
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flag = TTY_BREAK;
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else if (ch & UART011_DR_PE)
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flag = TTY_PARITY;
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else if (ch & UART011_DR_FE)
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flag = TTY_FRAME;
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}
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if (uart_handle_sysrq_char(&uap->port, ch & 255, regs))
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goto ignore_char;
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uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag);
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ignore_char:
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status = readw(uap->port.membase + UART01x_FR);
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}
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tty_flip_buffer_push(tty);
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return;
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}
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static void pl011_tx_chars(struct uart_amba_port *uap)
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{
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struct circ_buf *xmit = &uap->port.info->xmit;
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int count;
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if (uap->port.x_char) {
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writew(uap->port.x_char, uap->port.membase + UART01x_DR);
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uap->port.icount.tx++;
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uap->port.x_char = 0;
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return;
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}
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if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
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pl011_stop_tx(&uap->port);
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return;
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}
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count = uap->port.fifosize >> 1;
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do {
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writew(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
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xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
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uap->port.icount.tx++;
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if (uart_circ_empty(xmit))
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break;
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} while (--count > 0);
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if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
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uart_write_wakeup(&uap->port);
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if (uart_circ_empty(xmit))
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pl011_stop_tx(&uap->port);
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}
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static void pl011_modem_status(struct uart_amba_port *uap)
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{
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unsigned int status, delta;
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status = readw(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
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delta = status ^ uap->old_status;
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uap->old_status = status;
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if (!delta)
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return;
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if (delta & UART01x_FR_DCD)
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uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
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if (delta & UART01x_FR_DSR)
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uap->port.icount.dsr++;
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if (delta & UART01x_FR_CTS)
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uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);
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wake_up_interruptible(&uap->port.info->delta_msr_wait);
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}
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static irqreturn_t pl011_int(int irq, void *dev_id, struct pt_regs *regs)
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{
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struct uart_amba_port *uap = dev_id;
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unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
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int handled = 0;
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spin_lock(&uap->port.lock);
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status = readw(uap->port.membase + UART011_MIS);
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if (status) {
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do {
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writew(status & ~(UART011_TXIS|UART011_RTIS|
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UART011_RXIS),
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uap->port.membase + UART011_ICR);
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if (status & (UART011_RTIS|UART011_RXIS))
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#ifdef SUPPORT_SYSRQ
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pl011_rx_chars(uap, regs);
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#else
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pl011_rx_chars(uap);
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#endif
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if (status & (UART011_DSRMIS|UART011_DCDMIS|
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UART011_CTSMIS|UART011_RIMIS))
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pl011_modem_status(uap);
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if (status & UART011_TXIS)
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pl011_tx_chars(uap);
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if (pass_counter-- == 0)
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break;
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status = readw(uap->port.membase + UART011_MIS);
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} while (status != 0);
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handled = 1;
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}
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spin_unlock(&uap->port.lock);
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return IRQ_RETVAL(handled);
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}
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static unsigned int pl01x_tx_empty(struct uart_port *port)
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{
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struct uart_amba_port *uap = (struct uart_amba_port *)port;
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unsigned int status = readw(uap->port.membase + UART01x_FR);
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return status & (UART01x_FR_BUSY|UART01x_FR_TXFF) ? 0 : TIOCSER_TEMT;
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}
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static unsigned int pl01x_get_mctrl(struct uart_port *port)
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{
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struct uart_amba_port *uap = (struct uart_amba_port *)port;
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unsigned int result = 0;
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unsigned int status = readw(uap->port.membase + UART01x_FR);
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#define BIT(uartbit, tiocmbit) \
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if (status & uartbit) \
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result |= tiocmbit
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BIT(UART01x_FR_DCD, TIOCM_CAR);
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BIT(UART01x_FR_DSR, TIOCM_DSR);
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BIT(UART01x_FR_CTS, TIOCM_CTS);
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BIT(UART011_FR_RI, TIOCM_RNG);
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#undef BIT
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return result;
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}
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static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
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{
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struct uart_amba_port *uap = (struct uart_amba_port *)port;
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unsigned int cr;
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cr = readw(uap->port.membase + UART011_CR);
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#define BIT(tiocmbit, uartbit) \
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if (mctrl & tiocmbit) \
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cr |= uartbit; \
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else \
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cr &= ~uartbit
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BIT(TIOCM_RTS, UART011_CR_RTS);
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BIT(TIOCM_DTR, UART011_CR_DTR);
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BIT(TIOCM_OUT1, UART011_CR_OUT1);
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BIT(TIOCM_OUT2, UART011_CR_OUT2);
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BIT(TIOCM_LOOP, UART011_CR_LBE);
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#undef BIT
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writew(cr, uap->port.membase + UART011_CR);
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}
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static void pl011_break_ctl(struct uart_port *port, int break_state)
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{
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struct uart_amba_port *uap = (struct uart_amba_port *)port;
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unsigned long flags;
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unsigned int lcr_h;
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spin_lock_irqsave(&uap->port.lock, flags);
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lcr_h = readw(uap->port.membase + UART011_LCRH);
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if (break_state == -1)
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lcr_h |= UART01x_LCRH_BRK;
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else
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lcr_h &= ~UART01x_LCRH_BRK;
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writew(lcr_h, uap->port.membase + UART011_LCRH);
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spin_unlock_irqrestore(&uap->port.lock, flags);
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}
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static int pl011_startup(struct uart_port *port)
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{
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struct uart_amba_port *uap = (struct uart_amba_port *)port;
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unsigned int cr;
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int retval;
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/*
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* Try to enable the clock producer.
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*/
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retval = clk_enable(uap->clk);
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if (retval)
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goto out;
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uap->port.uartclk = clk_get_rate(uap->clk);
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/*
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* Allocate the IRQ
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*/
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retval = request_irq(uap->port.irq, pl011_int, 0, "uart-pl011", uap);
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if (retval)
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goto clk_dis;
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writew(UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
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uap->port.membase + UART011_IFLS);
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/*
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* Provoke TX FIFO interrupt into asserting.
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*/
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cr = UART01x_CR_UARTEN | UART011_CR_TXE | UART011_CR_LBE;
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writew(cr, uap->port.membase + UART011_CR);
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writew(0, uap->port.membase + UART011_FBRD);
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writew(1, uap->port.membase + UART011_IBRD);
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writew(0, uap->port.membase + UART011_LCRH);
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writew(0, uap->port.membase + UART01x_DR);
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while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_BUSY)
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barrier();
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cr = UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE;
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writew(cr, uap->port.membase + UART011_CR);
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/*
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* initialise the old status of the modem signals
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*/
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uap->old_status = readw(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
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/*
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* Finally, enable interrupts
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*/
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spin_lock_irq(&uap->port.lock);
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uap->im = UART011_RXIM | UART011_RTIM;
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writew(uap->im, uap->port.membase + UART011_IMSC);
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spin_unlock_irq(&uap->port.lock);
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return 0;
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clk_dis:
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clk_disable(uap->clk);
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out:
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return retval;
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}
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static void pl011_shutdown(struct uart_port *port)
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{
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struct uart_amba_port *uap = (struct uart_amba_port *)port;
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unsigned long val;
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/*
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* disable all interrupts
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*/
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spin_lock_irq(&uap->port.lock);
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uap->im = 0;
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writew(uap->im, uap->port.membase + UART011_IMSC);
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writew(0xffff, uap->port.membase + UART011_ICR);
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spin_unlock_irq(&uap->port.lock);
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/*
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* Free the interrupt
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*/
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free_irq(uap->port.irq, uap);
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/*
|
|
* disable the port
|
|
*/
|
|
writew(UART01x_CR_UARTEN | UART011_CR_TXE, uap->port.membase + UART011_CR);
|
|
|
|
/*
|
|
* disable break condition and fifos
|
|
*/
|
|
val = readw(uap->port.membase + UART011_LCRH);
|
|
val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
|
|
writew(val, uap->port.membase + UART011_LCRH);
|
|
|
|
/*
|
|
* Shut down the clock producer
|
|
*/
|
|
clk_disable(uap->clk);
|
|
}
|
|
|
|
static void
|
|
pl011_set_termios(struct uart_port *port, struct termios *termios,
|
|
struct termios *old)
|
|
{
|
|
unsigned int lcr_h, old_cr;
|
|
unsigned long flags;
|
|
unsigned int baud, quot;
|
|
|
|
/*
|
|
* Ask the core to calculate the divisor for us.
|
|
*/
|
|
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
|
|
quot = port->uartclk * 4 / baud;
|
|
|
|
switch (termios->c_cflag & CSIZE) {
|
|
case CS5:
|
|
lcr_h = UART01x_LCRH_WLEN_5;
|
|
break;
|
|
case CS6:
|
|
lcr_h = UART01x_LCRH_WLEN_6;
|
|
break;
|
|
case CS7:
|
|
lcr_h = UART01x_LCRH_WLEN_7;
|
|
break;
|
|
default: // CS8
|
|
lcr_h = UART01x_LCRH_WLEN_8;
|
|
break;
|
|
}
|
|
if (termios->c_cflag & CSTOPB)
|
|
lcr_h |= UART01x_LCRH_STP2;
|
|
if (termios->c_cflag & PARENB) {
|
|
lcr_h |= UART01x_LCRH_PEN;
|
|
if (!(termios->c_cflag & PARODD))
|
|
lcr_h |= UART01x_LCRH_EPS;
|
|
}
|
|
if (port->fifosize > 1)
|
|
lcr_h |= UART01x_LCRH_FEN;
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
|
|
/*
|
|
* Update the per-port timeout.
|
|
*/
|
|
uart_update_timeout(port, termios->c_cflag, baud);
|
|
|
|
port->read_status_mask = UART011_DR_OE | 255;
|
|
if (termios->c_iflag & INPCK)
|
|
port->read_status_mask |= UART011_DR_FE | UART011_DR_PE;
|
|
if (termios->c_iflag & (BRKINT | PARMRK))
|
|
port->read_status_mask |= UART011_DR_BE;
|
|
|
|
/*
|
|
* Characters to ignore
|
|
*/
|
|
port->ignore_status_mask = 0;
|
|
if (termios->c_iflag & IGNPAR)
|
|
port->ignore_status_mask |= UART011_DR_FE | UART011_DR_PE;
|
|
if (termios->c_iflag & IGNBRK) {
|
|
port->ignore_status_mask |= UART011_DR_BE;
|
|
/*
|
|
* If we're ignoring parity and break indicators,
|
|
* ignore overruns too (for real raw support).
|
|
*/
|
|
if (termios->c_iflag & IGNPAR)
|
|
port->ignore_status_mask |= UART011_DR_OE;
|
|
}
|
|
|
|
/*
|
|
* Ignore all characters if CREAD is not set.
|
|
*/
|
|
if ((termios->c_cflag & CREAD) == 0)
|
|
port->ignore_status_mask |= UART_DUMMY_DR_RX;
|
|
|
|
if (UART_ENABLE_MS(port, termios->c_cflag))
|
|
pl011_enable_ms(port);
|
|
|
|
/* first, disable everything */
|
|
old_cr = readw(port->membase + UART011_CR);
|
|
writew(0, port->membase + UART011_CR);
|
|
|
|
/* Set baud rate */
|
|
writew(quot & 0x3f, port->membase + UART011_FBRD);
|
|
writew(quot >> 6, port->membase + UART011_IBRD);
|
|
|
|
/*
|
|
* ----------v----------v----------v----------v-----
|
|
* NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
|
|
* ----------^----------^----------^----------^-----
|
|
*/
|
|
writew(lcr_h, port->membase + UART011_LCRH);
|
|
writew(old_cr, port->membase + UART011_CR);
|
|
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
|
|
static const char *pl011_type(struct uart_port *port)
|
|
{
|
|
return port->type == PORT_AMBA ? "AMBA/PL011" : NULL;
|
|
}
|
|
|
|
/*
|
|
* Release the memory region(s) being used by 'port'
|
|
*/
|
|
static void pl010_release_port(struct uart_port *port)
|
|
{
|
|
release_mem_region(port->mapbase, SZ_4K);
|
|
}
|
|
|
|
/*
|
|
* Request the memory region(s) being used by 'port'
|
|
*/
|
|
static int pl010_request_port(struct uart_port *port)
|
|
{
|
|
return request_mem_region(port->mapbase, SZ_4K, "uart-pl011")
|
|
!= NULL ? 0 : -EBUSY;
|
|
}
|
|
|
|
/*
|
|
* Configure/autoconfigure the port.
|
|
*/
|
|
static void pl010_config_port(struct uart_port *port, int flags)
|
|
{
|
|
if (flags & UART_CONFIG_TYPE) {
|
|
port->type = PORT_AMBA;
|
|
pl010_request_port(port);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* verify the new serial_struct (for TIOCSSERIAL).
|
|
*/
|
|
static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
|
|
{
|
|
int ret = 0;
|
|
if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
|
|
ret = -EINVAL;
|
|
if (ser->irq < 0 || ser->irq >= NR_IRQS)
|
|
ret = -EINVAL;
|
|
if (ser->baud_base < 9600)
|
|
ret = -EINVAL;
|
|
return ret;
|
|
}
|
|
|
|
static struct uart_ops amba_pl011_pops = {
|
|
.tx_empty = pl01x_tx_empty,
|
|
.set_mctrl = pl011_set_mctrl,
|
|
.get_mctrl = pl01x_get_mctrl,
|
|
.stop_tx = pl011_stop_tx,
|
|
.start_tx = pl011_start_tx,
|
|
.stop_rx = pl011_stop_rx,
|
|
.enable_ms = pl011_enable_ms,
|
|
.break_ctl = pl011_break_ctl,
|
|
.startup = pl011_startup,
|
|
.shutdown = pl011_shutdown,
|
|
.set_termios = pl011_set_termios,
|
|
.type = pl011_type,
|
|
.release_port = pl010_release_port,
|
|
.request_port = pl010_request_port,
|
|
.config_port = pl010_config_port,
|
|
.verify_port = pl010_verify_port,
|
|
};
|
|
|
|
static struct uart_amba_port *amba_ports[UART_NR];
|
|
|
|
#ifdef CONFIG_SERIAL_AMBA_PL011_CONSOLE
|
|
|
|
static inline void
|
|
pl011_console_write_char(struct uart_amba_port *uap, char ch)
|
|
{
|
|
unsigned int status;
|
|
|
|
do {
|
|
status = readw(uap->port.membase + UART01x_FR);
|
|
} while (status & UART01x_FR_TXFF);
|
|
writew(ch, uap->port.membase + UART01x_DR);
|
|
}
|
|
|
|
static void
|
|
pl011_console_write(struct console *co, const char *s, unsigned int count)
|
|
{
|
|
struct uart_amba_port *uap = amba_ports[co->index];
|
|
unsigned int status, old_cr, new_cr;
|
|
int i;
|
|
|
|
clk_enable(uap->clk);
|
|
|
|
/*
|
|
* First save the CR then disable the interrupts
|
|
*/
|
|
old_cr = readw(uap->port.membase + UART011_CR);
|
|
new_cr = old_cr & ~UART011_CR_CTSEN;
|
|
new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
|
|
writew(new_cr, uap->port.membase + UART011_CR);
|
|
|
|
/*
|
|
* Now, do each character
|
|
*/
|
|
for (i = 0; i < count; i++) {
|
|
pl011_console_write_char(uap, s[i]);
|
|
if (s[i] == '\n')
|
|
pl011_console_write_char(uap, '\r');
|
|
}
|
|
|
|
/*
|
|
* Finally, wait for transmitter to become empty
|
|
* and restore the TCR
|
|
*/
|
|
do {
|
|
status = readw(uap->port.membase + UART01x_FR);
|
|
} while (status & UART01x_FR_BUSY);
|
|
writew(old_cr, uap->port.membase + UART011_CR);
|
|
|
|
clk_disable(uap->clk);
|
|
}
|
|
|
|
static void __init
|
|
pl011_console_get_options(struct uart_amba_port *uap, int *baud,
|
|
int *parity, int *bits)
|
|
{
|
|
if (readw(uap->port.membase + UART011_CR) & UART01x_CR_UARTEN) {
|
|
unsigned int lcr_h, ibrd, fbrd;
|
|
|
|
lcr_h = readw(uap->port.membase + UART011_LCRH);
|
|
|
|
*parity = 'n';
|
|
if (lcr_h & UART01x_LCRH_PEN) {
|
|
if (lcr_h & UART01x_LCRH_EPS)
|
|
*parity = 'e';
|
|
else
|
|
*parity = 'o';
|
|
}
|
|
|
|
if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
|
|
*bits = 7;
|
|
else
|
|
*bits = 8;
|
|
|
|
ibrd = readw(uap->port.membase + UART011_IBRD);
|
|
fbrd = readw(uap->port.membase + UART011_FBRD);
|
|
|
|
*baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd);
|
|
}
|
|
}
|
|
|
|
static int __init pl011_console_setup(struct console *co, char *options)
|
|
{
|
|
struct uart_amba_port *uap;
|
|
int baud = 38400;
|
|
int bits = 8;
|
|
int parity = 'n';
|
|
int flow = 'n';
|
|
|
|
/*
|
|
* Check whether an invalid uart number has been specified, and
|
|
* if so, search for the first available port that does have
|
|
* console support.
|
|
*/
|
|
if (co->index >= UART_NR)
|
|
co->index = 0;
|
|
uap = amba_ports[co->index];
|
|
|
|
uap->port.uartclk = clk_get_rate(uap->clk);
|
|
|
|
if (options)
|
|
uart_parse_options(options, &baud, &parity, &bits, &flow);
|
|
else
|
|
pl011_console_get_options(uap, &baud, &parity, &bits);
|
|
|
|
return uart_set_options(&uap->port, co, baud, parity, bits, flow);
|
|
}
|
|
|
|
static struct uart_driver amba_reg;
|
|
static struct console amba_console = {
|
|
.name = "ttyAMA",
|
|
.write = pl011_console_write,
|
|
.device = uart_console_device,
|
|
.setup = pl011_console_setup,
|
|
.flags = CON_PRINTBUFFER,
|
|
.index = -1,
|
|
.data = &amba_reg,
|
|
};
|
|
|
|
#define AMBA_CONSOLE (&amba_console)
|
|
#else
|
|
#define AMBA_CONSOLE NULL
|
|
#endif
|
|
|
|
static struct uart_driver amba_reg = {
|
|
.owner = THIS_MODULE,
|
|
.driver_name = "ttyAMA",
|
|
.dev_name = "ttyAMA",
|
|
.major = SERIAL_AMBA_MAJOR,
|
|
.minor = SERIAL_AMBA_MINOR,
|
|
.nr = UART_NR,
|
|
.cons = AMBA_CONSOLE,
|
|
};
|
|
|
|
static int pl011_probe(struct amba_device *dev, void *id)
|
|
{
|
|
struct uart_amba_port *uap;
|
|
void __iomem *base;
|
|
int i, ret;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
|
|
if (amba_ports[i] == NULL)
|
|
break;
|
|
|
|
if (i == ARRAY_SIZE(amba_ports)) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
uap = kmalloc(sizeof(struct uart_amba_port), GFP_KERNEL);
|
|
if (uap == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
base = ioremap(dev->res.start, PAGE_SIZE);
|
|
if (!base) {
|
|
ret = -ENOMEM;
|
|
goto free;
|
|
}
|
|
|
|
memset(uap, 0, sizeof(struct uart_amba_port));
|
|
uap->clk = clk_get(&dev->dev, "UARTCLK");
|
|
if (IS_ERR(uap->clk)) {
|
|
ret = PTR_ERR(uap->clk);
|
|
goto unmap;
|
|
}
|
|
|
|
uap->port.dev = &dev->dev;
|
|
uap->port.mapbase = dev->res.start;
|
|
uap->port.membase = base;
|
|
uap->port.iotype = UPIO_MEM;
|
|
uap->port.irq = dev->irq[0];
|
|
uap->port.fifosize = 16;
|
|
uap->port.ops = &amba_pl011_pops;
|
|
uap->port.flags = UPF_BOOT_AUTOCONF;
|
|
uap->port.line = i;
|
|
|
|
amba_ports[i] = uap;
|
|
|
|
amba_set_drvdata(dev, uap);
|
|
ret = uart_add_one_port(&amba_reg, &uap->port);
|
|
if (ret) {
|
|
amba_set_drvdata(dev, NULL);
|
|
amba_ports[i] = NULL;
|
|
clk_put(uap->clk);
|
|
unmap:
|
|
iounmap(base);
|
|
free:
|
|
kfree(uap);
|
|
}
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int pl011_remove(struct amba_device *dev)
|
|
{
|
|
struct uart_amba_port *uap = amba_get_drvdata(dev);
|
|
int i;
|
|
|
|
amba_set_drvdata(dev, NULL);
|
|
|
|
uart_remove_one_port(&amba_reg, &uap->port);
|
|
|
|
for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
|
|
if (amba_ports[i] == uap)
|
|
amba_ports[i] = NULL;
|
|
|
|
iounmap(uap->port.membase);
|
|
clk_put(uap->clk);
|
|
kfree(uap);
|
|
return 0;
|
|
}
|
|
|
|
static struct amba_id pl011_ids[] __initdata = {
|
|
{
|
|
.id = 0x00041011,
|
|
.mask = 0x000fffff,
|
|
},
|
|
{ 0, 0 },
|
|
};
|
|
|
|
static struct amba_driver pl011_driver = {
|
|
.drv = {
|
|
.name = "uart-pl011",
|
|
},
|
|
.id_table = pl011_ids,
|
|
.probe = pl011_probe,
|
|
.remove = pl011_remove,
|
|
};
|
|
|
|
static int __init pl011_init(void)
|
|
{
|
|
int ret;
|
|
printk(KERN_INFO "Serial: AMBA PL011 UART driver\n");
|
|
|
|
ret = uart_register_driver(&amba_reg);
|
|
if (ret == 0) {
|
|
ret = amba_driver_register(&pl011_driver);
|
|
if (ret)
|
|
uart_unregister_driver(&amba_reg);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void __exit pl011_exit(void)
|
|
{
|
|
amba_driver_unregister(&pl011_driver);
|
|
uart_unregister_driver(&amba_reg);
|
|
}
|
|
|
|
module_init(pl011_init);
|
|
module_exit(pl011_exit);
|
|
|
|
MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
|
|
MODULE_DESCRIPTION("ARM AMBA serial port driver");
|
|
MODULE_LICENSE("GPL");
|