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linux/drivers/serial/atmel_serial.c
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

992 lines
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/*
* linux/drivers/char/at91_serial.c
*
* Driver for Atmel AT91 / AT32 Serial ports
* Copyright (C) 2003 Rick Bronson
*
* Based on drivers/char/serial_sa1100.c, by Deep Blue Solutions Ltd.
* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/serial.h>
#include <linux/clk.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/tty_flip.h>
#include <linux/platform_device.h>
#include <asm/io.h>
#include <asm/arch/at91rm9200_pdc.h>
#include <asm/mach/serial_at91.h>
#include <asm/arch/board.h>
#ifdef CONFIG_ARM
#include <asm/arch/system.h>
#include <asm/arch/gpio.h>
#endif
#include "atmel_serial.h"
#if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/serial_core.h>
#ifdef CONFIG_SERIAL_ATMEL_TTYAT
/* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we
* should coexist with the 8250 driver, such as if we have an external 16C550
* UART. */
#define SERIAL_ATMEL_MAJOR 204
#define MINOR_START 154
#define ATMEL_DEVICENAME "ttyAT"
#else
/* Use device name ttyS, major 4, minor 64-68. This is the usual serial port
* name, but it is legally reserved for the 8250 driver. */
#define SERIAL_ATMEL_MAJOR TTY_MAJOR
#define MINOR_START 64
#define ATMEL_DEVICENAME "ttyS"
#endif
#define ATMEL_ISR_PASS_LIMIT 256
#define UART_PUT_CR(port,v) writel(v, (port)->membase + ATMEL_US_CR)
#define UART_GET_MR(port) readl((port)->membase + ATMEL_US_MR)
#define UART_PUT_MR(port,v) writel(v, (port)->membase + ATMEL_US_MR)
#define UART_PUT_IER(port,v) writel(v, (port)->membase + ATMEL_US_IER)
#define UART_PUT_IDR(port,v) writel(v, (port)->membase + ATMEL_US_IDR)
#define UART_GET_IMR(port) readl((port)->membase + ATMEL_US_IMR)
#define UART_GET_CSR(port) readl((port)->membase + ATMEL_US_CSR)
#define UART_GET_CHAR(port) readl((port)->membase + ATMEL_US_RHR)
#define UART_PUT_CHAR(port,v) writel(v, (port)->membase + ATMEL_US_THR)
#define UART_GET_BRGR(port) readl((port)->membase + ATMEL_US_BRGR)
#define UART_PUT_BRGR(port,v) writel(v, (port)->membase + ATMEL_US_BRGR)
#define UART_PUT_RTOR(port,v) writel(v, (port)->membase + ATMEL_US_RTOR)
// #define UART_GET_CR(port) readl((port)->membase + ATMEL_US_CR) // is write-only
/* PDC registers */
#define UART_PUT_PTCR(port,v) writel(v, (port)->membase + ATMEL_PDC_PTCR)
#define UART_GET_PTSR(port) readl((port)->membase + ATMEL_PDC_PTSR)
#define UART_PUT_RPR(port,v) writel(v, (port)->membase + ATMEL_PDC_RPR)
#define UART_GET_RPR(port) readl((port)->membase + ATMEL_PDC_RPR)
#define UART_PUT_RCR(port,v) writel(v, (port)->membase + ATMEL_PDC_RCR)
#define UART_PUT_RNPR(port,v) writel(v, (port)->membase + ATMEL_PDC_RNPR)
#define UART_PUT_RNCR(port,v) writel(v, (port)->membase + ATMEL_PDC_RNCR)
#define UART_PUT_TPR(port,v) writel(v, (port)->membase + ATMEL_PDC_TPR)
#define UART_PUT_TCR(port,v) writel(v, (port)->membase + ATMEL_PDC_TCR)
//#define UART_PUT_TNPR(port,v) writel(v, (port)->membase + ATMEL_PDC_TNPR)
//#define UART_PUT_TNCR(port,v) writel(v, (port)->membase + ATMEL_PDC_TNCR)
static int (*atmel_open_hook)(struct uart_port *);
static void (*atmel_close_hook)(struct uart_port *);
/*
* We wrap our port structure around the generic uart_port.
*/
struct atmel_uart_port {
struct uart_port uart; /* uart */
struct clk *clk; /* uart clock */
unsigned short suspended; /* is port suspended? */
};
static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
#ifdef SUPPORT_SYSRQ
static struct console atmel_console;
#endif
/*
* Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
*/
static u_int atmel_tx_empty(struct uart_port *port)
{
return (UART_GET_CSR(port) & ATMEL_US_TXEMPTY) ? TIOCSER_TEMT : 0;
}
/*
* Set state of the modem control output lines
*/
static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
{
unsigned int control = 0;
unsigned int mode;
#ifdef CONFIG_ARM
if (arch_identify() == ARCH_ID_AT91RM9200) {
/*
* AT91RM9200 Errata #39: RTS0 is not internally connected to PA21.
* We need to drive the pin manually.
*/
if (port->mapbase == AT91RM9200_BASE_US0) {
if (mctrl & TIOCM_RTS)
at91_set_gpio_value(AT91_PIN_PA21, 0);
else
at91_set_gpio_value(AT91_PIN_PA21, 1);
}
}
#endif
if (mctrl & TIOCM_RTS)
control |= ATMEL_US_RTSEN;
else
control |= ATMEL_US_RTSDIS;
if (mctrl & TIOCM_DTR)
control |= ATMEL_US_DTREN;
else
control |= ATMEL_US_DTRDIS;
UART_PUT_CR(port, control);
/* Local loopback mode? */
mode = UART_GET_MR(port) & ~ATMEL_US_CHMODE;
if (mctrl & TIOCM_LOOP)
mode |= ATMEL_US_CHMODE_LOC_LOOP;
else
mode |= ATMEL_US_CHMODE_NORMAL;
UART_PUT_MR(port, mode);
}
/*
* Get state of the modem control input lines
*/
static u_int atmel_get_mctrl(struct uart_port *port)
{
unsigned int status, ret = 0;
status = UART_GET_CSR(port);
/*
* The control signals are active low.
*/
if (!(status & ATMEL_US_DCD))
ret |= TIOCM_CD;
if (!(status & ATMEL_US_CTS))
ret |= TIOCM_CTS;
if (!(status & ATMEL_US_DSR))
ret |= TIOCM_DSR;
if (!(status & ATMEL_US_RI))
ret |= TIOCM_RI;
return ret;
}
/*
* Stop transmitting.
*/
static void atmel_stop_tx(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
UART_PUT_IDR(port, ATMEL_US_TXRDY);
}
/*
* Start transmitting.
*/
static void atmel_start_tx(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
UART_PUT_IER(port, ATMEL_US_TXRDY);
}
/*
* Stop receiving - port is in process of being closed.
*/
static void atmel_stop_rx(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
UART_PUT_IDR(port, ATMEL_US_RXRDY);
}
/*
* Enable modem status interrupts
*/
static void atmel_enable_ms(struct uart_port *port)
{
UART_PUT_IER(port, ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC | ATMEL_US_CTSIC);
}
/*
* Control the transmission of a break signal
*/
static void atmel_break_ctl(struct uart_port *port, int break_state)
{
if (break_state != 0)
UART_PUT_CR(port, ATMEL_US_STTBRK); /* start break */
else
UART_PUT_CR(port, ATMEL_US_STPBRK); /* stop break */
}
/*
* Characters received (called from interrupt handler)
*/
static void atmel_rx_chars(struct uart_port *port)
{
struct tty_struct *tty = port->info->tty;
unsigned int status, ch, flg;
status = UART_GET_CSR(port);
while (status & ATMEL_US_RXRDY) {
ch = UART_GET_CHAR(port);
port->icount.rx++;
flg = TTY_NORMAL;
/*
* note that the error handling code is
* out of the main execution path
*/
if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME | ATMEL_US_OVRE | ATMEL_US_RXBRK))) {
UART_PUT_CR(port, ATMEL_US_RSTSTA); /* clear error */
if (status & ATMEL_US_RXBRK) {
status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME); /* ignore side-effect */
port->icount.brk++;
if (uart_handle_break(port))
goto ignore_char;
}
if (status & ATMEL_US_PARE)
port->icount.parity++;
if (status & ATMEL_US_FRAME)
port->icount.frame++;
if (status & ATMEL_US_OVRE)
port->icount.overrun++;
status &= port->read_status_mask;
if (status & ATMEL_US_RXBRK)
flg = TTY_BREAK;
else if (status & ATMEL_US_PARE)
flg = TTY_PARITY;
else if (status & ATMEL_US_FRAME)
flg = TTY_FRAME;
}
if (uart_handle_sysrq_char(port, ch))
goto ignore_char;
uart_insert_char(port, status, ATMEL_US_OVRE, ch, flg);
ignore_char:
status = UART_GET_CSR(port);
}
tty_flip_buffer_push(tty);
}
/*
* Transmit characters (called from interrupt handler)
*/
static void atmel_tx_chars(struct uart_port *port)
{
struct circ_buf *xmit = &port->info->xmit;
if (port->x_char) {
UART_PUT_CHAR(port, port->x_char);
port->icount.tx++;
port->x_char = 0;
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
atmel_stop_tx(port);
return;
}
while (UART_GET_CSR(port) & ATMEL_US_TXRDY) {
UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
if (uart_circ_empty(xmit))
break;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (uart_circ_empty(xmit))
atmel_stop_tx(port);
}
/*
* Interrupt handler
*/
static irqreturn_t atmel_interrupt(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
unsigned int status, pending, pass_counter = 0;
status = UART_GET_CSR(port);
pending = status & UART_GET_IMR(port);
while (pending) {
/* Interrupt receive */
if (pending & ATMEL_US_RXRDY)
atmel_rx_chars(port);
// TODO: All reads to CSR will clear these interrupts!
if (pending & ATMEL_US_RIIC) port->icount.rng++;
if (pending & ATMEL_US_DSRIC) port->icount.dsr++;
if (pending & ATMEL_US_DCDIC)
uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
if (pending & ATMEL_US_CTSIC)
uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC | ATMEL_US_CTSIC))
wake_up_interruptible(&port->info->delta_msr_wait);
/* Interrupt transmit */
if (pending & ATMEL_US_TXRDY)
atmel_tx_chars(port);
if (pass_counter++ > ATMEL_ISR_PASS_LIMIT)
break;
status = UART_GET_CSR(port);
pending = status & UART_GET_IMR(port);
}
return IRQ_HANDLED;
}
/*
* Perform initialization and enable port for reception
*/
static int atmel_startup(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
int retval;
/*
* Ensure that no interrupts are enabled otherwise when
* request_irq() is called we could get stuck trying to
* handle an unexpected interrupt
*/
UART_PUT_IDR(port, -1);
/*
* Allocate the IRQ
*/
retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED, "atmel_serial", port);
if (retval) {
printk("atmel_serial: atmel_startup - Can't get irq\n");
return retval;
}
/*
* If there is a specific "open" function (to register
* control line interrupts)
*/
if (atmel_open_hook) {
retval = atmel_open_hook(port);
if (retval) {
free_irq(port->irq, port);
return retval;
}
}
/*
* Finally, enable the serial port
*/
UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN); /* enable xmit & rcvr */
UART_PUT_IER(port, ATMEL_US_RXRDY); /* enable receive only */
return 0;
}
/*
* Disable the port
*/
static void atmel_shutdown(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
/*
* Disable all interrupts, port and break condition.
*/
UART_PUT_CR(port, ATMEL_US_RSTSTA);
UART_PUT_IDR(port, -1);
/*
* Free the interrupt
*/
free_irq(port->irq, port);
/*
* If there is a specific "close" function (to unregister
* control line interrupts)
*/
if (atmel_close_hook)
atmel_close_hook(port);
}
/*
* Power / Clock management.
*/
static void atmel_serial_pm(struct uart_port *port, unsigned int state, unsigned int oldstate)
{
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
switch (state) {
case 0:
/*
* Enable the peripheral clock for this serial port.
* This is called on uart_open() or a resume event.
*/
clk_enable(atmel_port->clk);
break;
case 3:
/*
* Disable the peripheral clock for this serial port.
* This is called on uart_close() or a suspend event.
*/
clk_disable(atmel_port->clk);
break;
default:
printk(KERN_ERR "atmel_serial: unknown pm %d\n", state);
}
}
/*
* Change the port parameters
*/
static void atmel_set_termios(struct uart_port *port, struct termios * termios, struct termios * old)
{
unsigned long flags;
unsigned int mode, imr, quot, baud;
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
quot = uart_get_divisor(port, baud);
/* Get current mode register */
mode = UART_GET_MR(port) & ~(ATMEL_US_CHRL | ATMEL_US_NBSTOP | ATMEL_US_PAR);
/* byte size */
switch (termios->c_cflag & CSIZE) {
case CS5:
mode |= ATMEL_US_CHRL_5;
break;
case CS6:
mode |= ATMEL_US_CHRL_6;
break;
case CS7:
mode |= ATMEL_US_CHRL_7;
break;
default:
mode |= ATMEL_US_CHRL_8;
break;
}
/* stop bits */
if (termios->c_cflag & CSTOPB)
mode |= ATMEL_US_NBSTOP_2;
/* parity */
if (termios->c_cflag & PARENB) {
if (termios->c_cflag & CMSPAR) { /* Mark or Space parity */
if (termios->c_cflag & PARODD)
mode |= ATMEL_US_PAR_MARK;
else
mode |= ATMEL_US_PAR_SPACE;
}
else if (termios->c_cflag & PARODD)
mode |= ATMEL_US_PAR_ODD;
else
mode |= ATMEL_US_PAR_EVEN;
}
else
mode |= ATMEL_US_PAR_NONE;
spin_lock_irqsave(&port->lock, flags);
port->read_status_mask = ATMEL_US_OVRE;
if (termios->c_iflag & INPCK)
port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
if (termios->c_iflag & (BRKINT | PARMRK))
port->read_status_mask |= ATMEL_US_RXBRK;
/*
* Characters to ignore
*/
port->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
if (termios->c_iflag & IGNBRK) {
port->ignore_status_mask |= ATMEL_US_RXBRK;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= ATMEL_US_OVRE;
}
// TODO: Ignore all characters if CREAD is set.
/* update the per-port timeout */
uart_update_timeout(port, termios->c_cflag, baud);
/* disable interrupts and drain transmitter */
imr = UART_GET_IMR(port); /* get interrupt mask */
UART_PUT_IDR(port, -1); /* disable all interrupts */
while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY)) { barrier(); }
/* disable receiver and transmitter */
UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
/* set the parity, stop bits and data size */
UART_PUT_MR(port, mode);
/* set the baud rate */
UART_PUT_BRGR(port, quot);
UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
/* restore interrupts */
UART_PUT_IER(port, imr);
/* CTS flow-control and modem-status interrupts */
if (UART_ENABLE_MS(port, termios->c_cflag))
port->ops->enable_ms(port);
spin_unlock_irqrestore(&port->lock, flags);
}
/*
* Return string describing the specified port
*/
static const char *atmel_type(struct uart_port *port)
{
return (port->type == PORT_ATMEL) ? "ATMEL_SERIAL" : NULL;
}
/*
* Release the memory region(s) being used by 'port'.
*/
static void atmel_release_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
int size = pdev->resource[0].end - pdev->resource[0].start + 1;
release_mem_region(port->mapbase, size);
if (port->flags & UPF_IOREMAP) {
iounmap(port->membase);
port->membase = NULL;
}
}
/*
* Request the memory region(s) being used by 'port'.
*/
static int atmel_request_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
int size = pdev->resource[0].end - pdev->resource[0].start + 1;
if (!request_mem_region(port->mapbase, size, "atmel_serial"))
return -EBUSY;
if (port->flags & UPF_IOREMAP) {
port->membase = ioremap(port->mapbase, size);
if (port->membase == NULL) {
release_mem_region(port->mapbase, size);
return -ENOMEM;
}
}
return 0;
}
/*
* Configure/autoconfigure the port.
*/
static void atmel_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE) {
port->type = PORT_ATMEL;
atmel_request_port(port);
}
}
/*
* Verify the new serial_struct (for TIOCSSERIAL).
*/
static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser)
{
int ret = 0;
if (ser->type != PORT_UNKNOWN && ser->type != PORT_ATMEL)
ret = -EINVAL;
if (port->irq != ser->irq)
ret = -EINVAL;
if (ser->io_type != SERIAL_IO_MEM)
ret = -EINVAL;
if (port->uartclk / 16 != ser->baud_base)
ret = -EINVAL;
if ((void *)port->mapbase != ser->iomem_base)
ret = -EINVAL;
if (port->iobase != ser->port)
ret = -EINVAL;
if (ser->hub6 != 0)
ret = -EINVAL;
return ret;
}
static struct uart_ops atmel_pops = {
.tx_empty = atmel_tx_empty,
.set_mctrl = atmel_set_mctrl,
.get_mctrl = atmel_get_mctrl,
.stop_tx = atmel_stop_tx,
.start_tx = atmel_start_tx,
.stop_rx = atmel_stop_rx,
.enable_ms = atmel_enable_ms,
.break_ctl = atmel_break_ctl,
.startup = atmel_startup,
.shutdown = atmel_shutdown,
.set_termios = atmel_set_termios,
.type = atmel_type,
.release_port = atmel_release_port,
.request_port = atmel_request_port,
.config_port = atmel_config_port,
.verify_port = atmel_verify_port,
.pm = atmel_serial_pm,
};
/*
* Configure the port from the platform device resource info.
*/
static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, struct platform_device *pdev)
{
struct uart_port *port = &atmel_port->uart;
struct atmel_uart_data *data = pdev->dev.platform_data;
port->iotype = UPIO_MEM;
port->flags = UPF_BOOT_AUTOCONF;
port->ops = &atmel_pops;
port->fifosize = 1;
port->line = pdev->id;
port->dev = &pdev->dev;
port->mapbase = pdev->resource[0].start;
port->irq = pdev->resource[1].start;
if (data->regs)
/* Already mapped by setup code */
port->membase = data->regs;
else {
port->flags |= UPF_IOREMAP;
port->membase = NULL;
}
if (!atmel_port->clk) { /* for console, the clock could already be configured */
atmel_port->clk = clk_get(&pdev->dev, "usart");
clk_enable(atmel_port->clk);
port->uartclk = clk_get_rate(atmel_port->clk);
}
}
/*
* Register board-specific modem-control line handlers.
*/
void __init atmel_register_uart_fns(struct atmel_port_fns *fns)
{
if (fns->enable_ms)
atmel_pops.enable_ms = fns->enable_ms;
if (fns->get_mctrl)
atmel_pops.get_mctrl = fns->get_mctrl;
if (fns->set_mctrl)
atmel_pops.set_mctrl = fns->set_mctrl;
atmel_open_hook = fns->open;
atmel_close_hook = fns->close;
atmel_pops.pm = fns->pm;
atmel_pops.set_wake = fns->set_wake;
}
#ifdef CONFIG_SERIAL_ATMEL_CONSOLE
static void atmel_console_putchar(struct uart_port *port, int ch)
{
while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
barrier();
UART_PUT_CHAR(port, ch);
}
/*
* Interrupts are disabled on entering
*/
static void atmel_console_write(struct console *co, const char *s, u_int count)
{
struct uart_port *port = &atmel_ports[co->index].uart;
unsigned int status, imr;
/*
* First, save IMR and then disable interrupts
*/
imr = UART_GET_IMR(port); /* get interrupt mask */
UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY);
uart_console_write(port, s, count, atmel_console_putchar);
/*
* Finally, wait for transmitter to become empty
* and restore IMR
*/
do {
status = UART_GET_CSR(port);
} while (!(status & ATMEL_US_TXRDY));
UART_PUT_IER(port, imr); /* set interrupts back the way they were */
}
/*
* If the port was already initialised (eg, by a boot loader), try to determine
* the current setup.
*/
static void __init atmel_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits)
{
unsigned int mr, quot;
// TODO: CR is a write-only register
// unsigned int cr;
//
// cr = UART_GET_CR(port) & (ATMEL_US_RXEN | ATMEL_US_TXEN);
// if (cr == (ATMEL_US_RXEN | ATMEL_US_TXEN)) {
// /* ok, the port was enabled */
// }
mr = UART_GET_MR(port) & ATMEL_US_CHRL;
if (mr == ATMEL_US_CHRL_8)
*bits = 8;
else
*bits = 7;
mr = UART_GET_MR(port) & ATMEL_US_PAR;
if (mr == ATMEL_US_PAR_EVEN)
*parity = 'e';
else if (mr == ATMEL_US_PAR_ODD)
*parity = 'o';
/*
* The serial core only rounds down when matching this to a
* supported baud rate. Make sure we don't end up slightly
* lower than one of those, as it would make us fall through
* to a much lower baud rate than we really want.
*/
quot = UART_GET_BRGR(port);
*baud = port->uartclk / (16 * (quot - 1));
}
static int __init atmel_console_setup(struct console *co, char *options)
{
struct uart_port *port = &atmel_ports[co->index].uart;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (port->membase == 0) /* Port not initialized yet - delay setup */
return -ENODEV;
UART_PUT_IDR(port, -1); /* disable interrupts */
UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
atmel_console_get_options(port, &baud, &parity, &bits);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct uart_driver atmel_uart;
static struct console atmel_console = {
.name = ATMEL_DEVICENAME,
.write = atmel_console_write,
.device = uart_console_device,
.setup = atmel_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &atmel_uart,
};
#define ATMEL_CONSOLE_DEVICE &atmel_console
/*
* Early console initialization (before VM subsystem initialized).
*/
static int __init atmel_console_init(void)
{
if (atmel_default_console_device) {
add_preferred_console(ATMEL_DEVICENAME, atmel_default_console_device->id, NULL);
atmel_init_port(&(atmel_ports[atmel_default_console_device->id]), atmel_default_console_device);
register_console(&atmel_console);
}
return 0;
}
console_initcall(atmel_console_init);
/*
* Late console initialization.
*/
static int __init atmel_late_console_init(void)
{
if (atmel_default_console_device && !(atmel_console.flags & CON_ENABLED))
register_console(&atmel_console);
return 0;
}
core_initcall(atmel_late_console_init);
#else
#define ATMEL_CONSOLE_DEVICE NULL
#endif
static struct uart_driver atmel_uart = {
.owner = THIS_MODULE,
.driver_name = "atmel_serial",
.dev_name = ATMEL_DEVICENAME,
.major = SERIAL_ATMEL_MAJOR,
.minor = MINOR_START,
.nr = ATMEL_MAX_UART,
.cons = ATMEL_CONSOLE_DEVICE,
};
#ifdef CONFIG_PM
static int atmel_serial_suspend(struct platform_device *pdev, pm_message_t state)
{
struct uart_port *port = platform_get_drvdata(pdev);
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
if (device_may_wakeup(&pdev->dev) && !at91_suspend_entering_slow_clock())
enable_irq_wake(port->irq);
else {
disable_irq_wake(port->irq);
uart_suspend_port(&atmel_uart, port);
atmel_port->suspended = 1;
}
return 0;
}
static int atmel_serial_resume(struct platform_device *pdev)
{
struct uart_port *port = platform_get_drvdata(pdev);
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
if (atmel_port->suspended) {
uart_resume_port(&atmel_uart, port);
atmel_port->suspended = 0;
}
return 0;
}
#else
#define atmel_serial_suspend NULL
#define atmel_serial_resume NULL
#endif
static int __devinit atmel_serial_probe(struct platform_device *pdev)
{
struct atmel_uart_port *port;
int ret;
port = &atmel_ports[pdev->id];
atmel_init_port(port, pdev);
ret = uart_add_one_port(&atmel_uart, &port->uart);
if (!ret) {
device_init_wakeup(&pdev->dev, 1);
platform_set_drvdata(pdev, port);
}
return ret;
}
static int __devexit atmel_serial_remove(struct platform_device *pdev)
{
struct uart_port *port = platform_get_drvdata(pdev);
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
int ret = 0;
clk_disable(atmel_port->clk);
clk_put(atmel_port->clk);
device_init_wakeup(&pdev->dev, 0);
platform_set_drvdata(pdev, NULL);
if (port) {
ret = uart_remove_one_port(&atmel_uart, port);
kfree(port);
}
return ret;
}
static struct platform_driver atmel_serial_driver = {
.probe = atmel_serial_probe,
.remove = __devexit_p(atmel_serial_remove),
.suspend = atmel_serial_suspend,
.resume = atmel_serial_resume,
.driver = {
.name = "atmel_usart",
.owner = THIS_MODULE,
},
};
static int __init atmel_serial_init(void)
{
int ret;
ret = uart_register_driver(&atmel_uart);
if (ret)
return ret;
ret = platform_driver_register(&atmel_serial_driver);
if (ret)
uart_unregister_driver(&atmel_uart);
return ret;
}
static void __exit atmel_serial_exit(void)
{
platform_driver_unregister(&atmel_serial_driver);
uart_unregister_driver(&atmel_uart);
}
module_init(atmel_serial_init);
module_exit(atmel_serial_exit);
MODULE_AUTHOR("Rick Bronson");
MODULE_DESCRIPTION("Atmel AT91 / AT32 serial port driver");
MODULE_LICENSE("GPL");
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