linux/drivers/tty/serial/sa1100.c
Viresh Kumar 53e0e6706c tty: serial: sa1100: drop uart_port->lock before calling tty_flip_buffer_push()
The current driver triggers a lockdep warning for if tty_flip_buffer_push() is
called with uart_port->lock locked. This never shows up on UP kernels and comes
up only on SMP kernels.

Crash looks like this (produced with samsung.c driver):

-----
[<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14)
[<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac)
[<c035da34>] (dump_stack+0x6c/0xac) from [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8)
[<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) from [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0)
[<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0x38) from [<c020a1a8>] (s3c24xx_serial_rx_chars+0)
[<c020a1a8>] (s3c24xx_serial_rx_chars+0x12c/0x260) from [<c020aae8>] (s3c64xx_serial_handle_irq+)
[<c020aae8>] (s3c64xx_serial_handle_irq+0x48/0x60) from [<c006aaa0>] (handle_irq_event_percpu+0x)
[<c006aaa0>] (handle_irq_event_percpu+0x50/0x194) from [<c006ac20>] (handle_irq_event+0x3c/0x5c)
[<c006ac20>] (handle_irq_event+0x3c/0x5c) from [<c006d864>] (handle_fasteoi_irq+0x80/0x13c)
[<c006d864>] (handle_fasteoi_irq+0x80/0x13c) from [<c006a4a4>] (generic_handle_irq+0x20/0x30)
[<c006a4a4>] (generic_handle_irq+0x20/0x30) from [<c000f454>] (handle_IRQ+0x38/0x94)
[<c000f454>] (handle_IRQ+0x38/0x94) from [<c0008538>] (gic_handle_irq+0x34/0x68)
[<c0008538>] (gic_handle_irq+0x34/0x68) from [<c00123c0>] (__irq_svc+0x40/0x70)
Exception stack(0xc04cdf70 to 0xc04cdfb8)
df60:                                     00000000 00000000 0000166e 00000000
df80: c04cc000 c050278f c050278f 00000001 c04d444c 410fc0f4 c03649b0 00000000
dfa0: 00000001 c04cdfb8 c000f758 c000f75c 60070013 ffffffff
[<c00123c0>] (__irq_svc+0x40/0x70) from [<c000f75c>] (arch_cpu_idle+0x28/0x30)
[<c000f75c>] (arch_cpu_idle+0x28/0x30) from [<c0054888>] (cpu_startup_entry+0x5c/0x148)
[<c0054888>] (cpu_startup_entry+0x5c/0x148) from [<c0497aa4>] (start_kernel+0x334/0x38c)
BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360
 lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1
CPU: 0 PID: 360 Comm: kworker/0:1 Not tainted 3.11.0-rc6-next-20130819-00003-g75485f1 #2
Workqueue: events flush_to_ldisc
[<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14)
[<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac)
[<c035da34>] (dump_stack+0x6c/0xac) from [<c01b581c>] (do_raw_spin_lock+0x100/0x17c)
[<c01b581c>] (do_raw_spin_lock+0x100/0x17c) from [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28)
[<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) from [<c0203224>] (uart_start+0x18/0x34)
[<c0203224>] (uart_start+0x18/0x34) from [<c01ef890>] (__receive_buf+0x4b4/0x738)
[<c01ef890>] (__receive_buf+0x4b4/0x738) from [<c01efb44>] (n_tty_receive_buf2+0x30/0x98)
[<c01efb44>] (n_tty_receive_buf2+0x30/0x98) from [<c01f2ba8>] (flush_to_ldisc+0xec/0x138)
[<c01f2ba8>] (flush_to_ldisc+0xec/0x138) from [<c0031af0>] (process_one_work+0xfc/0x348)
[<c0031af0>] (process_one_work+0xfc/0x348) from [<c0032138>] (worker_thread+0x138/0x37c)
[<c0032138>] (worker_thread+0x138/0x37c) from [<c0037a7c>] (kthread+0xa4/0xb0)
[<c0037a7c>] (kthread+0xa4/0xb0) from [<c000e5f8>] (ret_from_fork+0x14/0x3c)
-----

Release the port lock before calling tty_flip_buffer_push() and reacquire it
after the call.

Similar stuff was already done for few other drivers in the past, like:

commit 2389b27216
Author: Thomas Gleixner <tglx@linutronix.de>
Date:   Tue May 29 21:53:50 2007 +0100

    [ARM] 4417/1: Serial: Fix AMBA drivers locking

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-27 16:17:35 -07:00

918 lines
22 KiB
C

/*
* Driver for SA11x0 serial ports
*
* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
*
* Copyright (C) 2000 Deep Blue Solutions Ltd.
*
* 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
*/
#if defined(CONFIG_SERIAL_SA1100_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/platform_data/sa11x0-serial.h>
#include <linux/platform_device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/io.h>
#include <asm/irq.h>
#include <mach/hardware.h>
#include <mach/irqs.h>
/* We've been assigned a range on the "Low-density serial ports" major */
#define SERIAL_SA1100_MAJOR 204
#define MINOR_START 5
#define NR_PORTS 3
#define SA1100_ISR_PASS_LIMIT 256
/*
* Convert from ignore_status_mask or read_status_mask to UTSR[01]
*/
#define SM_TO_UTSR0(x) ((x) & 0xff)
#define SM_TO_UTSR1(x) ((x) >> 8)
#define UTSR0_TO_SM(x) ((x))
#define UTSR1_TO_SM(x) ((x) << 8)
#define UART_GET_UTCR0(sport) __raw_readl((sport)->port.membase + UTCR0)
#define UART_GET_UTCR1(sport) __raw_readl((sport)->port.membase + UTCR1)
#define UART_GET_UTCR2(sport) __raw_readl((sport)->port.membase + UTCR2)
#define UART_GET_UTCR3(sport) __raw_readl((sport)->port.membase + UTCR3)
#define UART_GET_UTSR0(sport) __raw_readl((sport)->port.membase + UTSR0)
#define UART_GET_UTSR1(sport) __raw_readl((sport)->port.membase + UTSR1)
#define UART_GET_CHAR(sport) __raw_readl((sport)->port.membase + UTDR)
#define UART_PUT_UTCR0(sport,v) __raw_writel((v),(sport)->port.membase + UTCR0)
#define UART_PUT_UTCR1(sport,v) __raw_writel((v),(sport)->port.membase + UTCR1)
#define UART_PUT_UTCR2(sport,v) __raw_writel((v),(sport)->port.membase + UTCR2)
#define UART_PUT_UTCR3(sport,v) __raw_writel((v),(sport)->port.membase + UTCR3)
#define UART_PUT_UTSR0(sport,v) __raw_writel((v),(sport)->port.membase + UTSR0)
#define UART_PUT_UTSR1(sport,v) __raw_writel((v),(sport)->port.membase + UTSR1)
#define UART_PUT_CHAR(sport,v) __raw_writel((v),(sport)->port.membase + UTDR)
/*
* This is the size of our serial port register set.
*/
#define UART_PORT_SIZE 0x24
/*
* This determines how often we check the modem status signals
* for any change. They generally aren't connected to an IRQ
* so we have to poll them. We also check immediately before
* filling the TX fifo incase CTS has been dropped.
*/
#define MCTRL_TIMEOUT (250*HZ/1000)
struct sa1100_port {
struct uart_port port;
struct timer_list timer;
unsigned int old_status;
};
/*
* Handle any change of modem status signal since we were last called.
*/
static void sa1100_mctrl_check(struct sa1100_port *sport)
{
unsigned int status, changed;
status = sport->port.ops->get_mctrl(&sport->port);
changed = status ^ sport->old_status;
if (changed == 0)
return;
sport->old_status = status;
if (changed & TIOCM_RI)
sport->port.icount.rng++;
if (changed & TIOCM_DSR)
sport->port.icount.dsr++;
if (changed & TIOCM_CAR)
uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
if (changed & TIOCM_CTS)
uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
}
/*
* This is our per-port timeout handler, for checking the
* modem status signals.
*/
static void sa1100_timeout(unsigned long data)
{
struct sa1100_port *sport = (struct sa1100_port *)data;
unsigned long flags;
if (sport->port.state) {
spin_lock_irqsave(&sport->port.lock, flags);
sa1100_mctrl_check(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
}
}
/*
* interrupts disabled on entry
*/
static void sa1100_stop_tx(struct uart_port *port)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
u32 utcr3;
utcr3 = UART_GET_UTCR3(sport);
UART_PUT_UTCR3(sport, utcr3 & ~UTCR3_TIE);
sport->port.read_status_mask &= ~UTSR0_TO_SM(UTSR0_TFS);
}
/*
* port locked and interrupts disabled
*/
static void sa1100_start_tx(struct uart_port *port)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
u32 utcr3;
utcr3 = UART_GET_UTCR3(sport);
sport->port.read_status_mask |= UTSR0_TO_SM(UTSR0_TFS);
UART_PUT_UTCR3(sport, utcr3 | UTCR3_TIE);
}
/*
* Interrupts enabled
*/
static void sa1100_stop_rx(struct uart_port *port)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
u32 utcr3;
utcr3 = UART_GET_UTCR3(sport);
UART_PUT_UTCR3(sport, utcr3 & ~UTCR3_RIE);
}
/*
* Set the modem control timer to fire immediately.
*/
static void sa1100_enable_ms(struct uart_port *port)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
mod_timer(&sport->timer, jiffies);
}
static void
sa1100_rx_chars(struct sa1100_port *sport)
{
unsigned int status, ch, flg;
status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) |
UTSR0_TO_SM(UART_GET_UTSR0(sport));
while (status & UTSR1_TO_SM(UTSR1_RNE)) {
ch = UART_GET_CHAR(sport);
sport->port.icount.rx++;
flg = TTY_NORMAL;
/*
* note that the error handling code is
* out of the main execution path
*/
if (status & UTSR1_TO_SM(UTSR1_PRE | UTSR1_FRE | UTSR1_ROR)) {
if (status & UTSR1_TO_SM(UTSR1_PRE))
sport->port.icount.parity++;
else if (status & UTSR1_TO_SM(UTSR1_FRE))
sport->port.icount.frame++;
if (status & UTSR1_TO_SM(UTSR1_ROR))
sport->port.icount.overrun++;
status &= sport->port.read_status_mask;
if (status & UTSR1_TO_SM(UTSR1_PRE))
flg = TTY_PARITY;
else if (status & UTSR1_TO_SM(UTSR1_FRE))
flg = TTY_FRAME;
#ifdef SUPPORT_SYSRQ
sport->port.sysrq = 0;
#endif
}
if (uart_handle_sysrq_char(&sport->port, ch))
goto ignore_char;
uart_insert_char(&sport->port, status, UTSR1_TO_SM(UTSR1_ROR), ch, flg);
ignore_char:
status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) |
UTSR0_TO_SM(UART_GET_UTSR0(sport));
}
spin_unlock(&sport->port.lock);
tty_flip_buffer_push(&sport->port.state->port);
spin_lock(&sport->port.lock);
}
static void sa1100_tx_chars(struct sa1100_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
if (sport->port.x_char) {
UART_PUT_CHAR(sport, sport->port.x_char);
sport->port.icount.tx++;
sport->port.x_char = 0;
return;
}
/*
* Check the modem control lines before
* transmitting anything.
*/
sa1100_mctrl_check(sport);
if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
sa1100_stop_tx(&sport->port);
return;
}
/*
* Tried using FIFO (not checking TNF) for fifo fill:
* still had the '4 bytes repeated' problem.
*/
while (UART_GET_UTSR1(sport) & UTSR1_TNF) {
UART_PUT_CHAR(sport, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx++;
if (uart_circ_empty(xmit))
break;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
if (uart_circ_empty(xmit))
sa1100_stop_tx(&sport->port);
}
static irqreturn_t sa1100_int(int irq, void *dev_id)
{
struct sa1100_port *sport = dev_id;
unsigned int status, pass_counter = 0;
spin_lock(&sport->port.lock);
status = UART_GET_UTSR0(sport);
status &= SM_TO_UTSR0(sport->port.read_status_mask) | ~UTSR0_TFS;
do {
if (status & (UTSR0_RFS | UTSR0_RID)) {
/* Clear the receiver idle bit, if set */
if (status & UTSR0_RID)
UART_PUT_UTSR0(sport, UTSR0_RID);
sa1100_rx_chars(sport);
}
/* Clear the relevant break bits */
if (status & (UTSR0_RBB | UTSR0_REB))
UART_PUT_UTSR0(sport, status & (UTSR0_RBB | UTSR0_REB));
if (status & UTSR0_RBB)
sport->port.icount.brk++;
if (status & UTSR0_REB)
uart_handle_break(&sport->port);
if (status & UTSR0_TFS)
sa1100_tx_chars(sport);
if (pass_counter++ > SA1100_ISR_PASS_LIMIT)
break;
status = UART_GET_UTSR0(sport);
status &= SM_TO_UTSR0(sport->port.read_status_mask) |
~UTSR0_TFS;
} while (status & (UTSR0_TFS | UTSR0_RFS | UTSR0_RID));
spin_unlock(&sport->port.lock);
return IRQ_HANDLED;
}
/*
* Return TIOCSER_TEMT when transmitter is not busy.
*/
static unsigned int sa1100_tx_empty(struct uart_port *port)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
return UART_GET_UTSR1(sport) & UTSR1_TBY ? 0 : TIOCSER_TEMT;
}
static unsigned int sa1100_get_mctrl(struct uart_port *port)
{
return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
}
static void sa1100_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
}
/*
* Interrupts always disabled.
*/
static void sa1100_break_ctl(struct uart_port *port, int break_state)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
unsigned long flags;
unsigned int utcr3;
spin_lock_irqsave(&sport->port.lock, flags);
utcr3 = UART_GET_UTCR3(sport);
if (break_state == -1)
utcr3 |= UTCR3_BRK;
else
utcr3 &= ~UTCR3_BRK;
UART_PUT_UTCR3(sport, utcr3);
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static int sa1100_startup(struct uart_port *port)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
int retval;
/*
* Allocate the IRQ
*/
retval = request_irq(sport->port.irq, sa1100_int, 0,
"sa11x0-uart", sport);
if (retval)
return retval;
/*
* Finally, clear and enable interrupts
*/
UART_PUT_UTSR0(sport, -1);
UART_PUT_UTCR3(sport, UTCR3_RXE | UTCR3_TXE | UTCR3_RIE);
/*
* Enable modem status interrupts
*/
spin_lock_irq(&sport->port.lock);
sa1100_enable_ms(&sport->port);
spin_unlock_irq(&sport->port.lock);
return 0;
}
static void sa1100_shutdown(struct uart_port *port)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
/*
* Stop our timer.
*/
del_timer_sync(&sport->timer);
/*
* Free the interrupt
*/
free_irq(sport->port.irq, sport);
/*
* Disable all interrupts, port and break condition.
*/
UART_PUT_UTCR3(sport, 0);
}
static void
sa1100_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
unsigned long flags;
unsigned int utcr0, old_utcr3, baud, quot;
unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
/*
* We only support CS7 and CS8.
*/
while ((termios->c_cflag & CSIZE) != CS7 &&
(termios->c_cflag & CSIZE) != CS8) {
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= old_csize;
old_csize = CS8;
}
if ((termios->c_cflag & CSIZE) == CS8)
utcr0 = UTCR0_DSS;
else
utcr0 = 0;
if (termios->c_cflag & CSTOPB)
utcr0 |= UTCR0_SBS;
if (termios->c_cflag & PARENB) {
utcr0 |= UTCR0_PE;
if (!(termios->c_cflag & PARODD))
utcr0 |= UTCR0_OES;
}
/*
* Ask the core to calculate the divisor for us.
*/
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
quot = uart_get_divisor(port, baud);
spin_lock_irqsave(&sport->port.lock, flags);
sport->port.read_status_mask &= UTSR0_TO_SM(UTSR0_TFS);
sport->port.read_status_mask |= UTSR1_TO_SM(UTSR1_ROR);
if (termios->c_iflag & INPCK)
sport->port.read_status_mask |=
UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
if (termios->c_iflag & (BRKINT | PARMRK))
sport->port.read_status_mask |=
UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);
/*
* Characters to ignore
*/
sport->port.ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
sport->port.ignore_status_mask |=
UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
if (termios->c_iflag & IGNBRK) {
sport->port.ignore_status_mask |=
UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
sport->port.ignore_status_mask |=
UTSR1_TO_SM(UTSR1_ROR);
}
del_timer_sync(&sport->timer);
/*
* Update the per-port timeout.
*/
uart_update_timeout(port, termios->c_cflag, baud);
/*
* disable interrupts and drain transmitter
*/
old_utcr3 = UART_GET_UTCR3(sport);
UART_PUT_UTCR3(sport, old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE));
while (UART_GET_UTSR1(sport) & UTSR1_TBY)
barrier();
/* then, disable everything */
UART_PUT_UTCR3(sport, 0);
/* set the parity, stop bits and data size */
UART_PUT_UTCR0(sport, utcr0);
/* set the baud rate */
quot -= 1;
UART_PUT_UTCR1(sport, ((quot & 0xf00) >> 8));
UART_PUT_UTCR2(sport, (quot & 0xff));
UART_PUT_UTSR0(sport, -1);
UART_PUT_UTCR3(sport, old_utcr3);
if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
sa1100_enable_ms(&sport->port);
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static const char *sa1100_type(struct uart_port *port)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
return sport->port.type == PORT_SA1100 ? "SA1100" : NULL;
}
/*
* Release the memory region(s) being used by 'port'.
*/
static void sa1100_release_port(struct uart_port *port)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
release_mem_region(sport->port.mapbase, UART_PORT_SIZE);
}
/*
* Request the memory region(s) being used by 'port'.
*/
static int sa1100_request_port(struct uart_port *port)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
return request_mem_region(sport->port.mapbase, UART_PORT_SIZE,
"sa11x0-uart") != NULL ? 0 : -EBUSY;
}
/*
* Configure/autoconfigure the port.
*/
static void sa1100_config_port(struct uart_port *port, int flags)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
if (flags & UART_CONFIG_TYPE &&
sa1100_request_port(&sport->port) == 0)
sport->port.type = PORT_SA1100;
}
/*
* Verify the new serial_struct (for TIOCSSERIAL).
* The only change we allow are to the flags and type, and
* even then only between PORT_SA1100 and PORT_UNKNOWN
*/
static int
sa1100_verify_port(struct uart_port *port, struct serial_struct *ser)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
int ret = 0;
if (ser->type != PORT_UNKNOWN && ser->type != PORT_SA1100)
ret = -EINVAL;
if (sport->port.irq != ser->irq)
ret = -EINVAL;
if (ser->io_type != SERIAL_IO_MEM)
ret = -EINVAL;
if (sport->port.uartclk / 16 != ser->baud_base)
ret = -EINVAL;
if ((void *)sport->port.mapbase != ser->iomem_base)
ret = -EINVAL;
if (sport->port.iobase != ser->port)
ret = -EINVAL;
if (ser->hub6 != 0)
ret = -EINVAL;
return ret;
}
static struct uart_ops sa1100_pops = {
.tx_empty = sa1100_tx_empty,
.set_mctrl = sa1100_set_mctrl,
.get_mctrl = sa1100_get_mctrl,
.stop_tx = sa1100_stop_tx,
.start_tx = sa1100_start_tx,
.stop_rx = sa1100_stop_rx,
.enable_ms = sa1100_enable_ms,
.break_ctl = sa1100_break_ctl,
.startup = sa1100_startup,
.shutdown = sa1100_shutdown,
.set_termios = sa1100_set_termios,
.type = sa1100_type,
.release_port = sa1100_release_port,
.request_port = sa1100_request_port,
.config_port = sa1100_config_port,
.verify_port = sa1100_verify_port,
};
static struct sa1100_port sa1100_ports[NR_PORTS];
/*
* Setup the SA1100 serial ports. Note that we don't include the IrDA
* port here since we have our own SIR/FIR driver (see drivers/net/irda)
*
* Note also that we support "console=ttySAx" where "x" is either 0 or 1.
* Which serial port this ends up being depends on the machine you're
* running this kernel on. I'm not convinced that this is a good idea,
* but that's the way it traditionally works.
*
* Note that NanoEngine UART3 becomes UART2, and UART2 is no longer
* used here.
*/
static void __init sa1100_init_ports(void)
{
static int first = 1;
int i;
if (!first)
return;
first = 0;
for (i = 0; i < NR_PORTS; i++) {
sa1100_ports[i].port.uartclk = 3686400;
sa1100_ports[i].port.ops = &sa1100_pops;
sa1100_ports[i].port.fifosize = 8;
sa1100_ports[i].port.line = i;
sa1100_ports[i].port.iotype = UPIO_MEM;
init_timer(&sa1100_ports[i].timer);
sa1100_ports[i].timer.function = sa1100_timeout;
sa1100_ports[i].timer.data = (unsigned long)&sa1100_ports[i];
}
/*
* make transmit lines outputs, so that when the port
* is closed, the output is in the MARK state.
*/
PPDR |= PPC_TXD1 | PPC_TXD3;
PPSR |= PPC_TXD1 | PPC_TXD3;
}
void sa1100_register_uart_fns(struct sa1100_port_fns *fns)
{
if (fns->get_mctrl)
sa1100_pops.get_mctrl = fns->get_mctrl;
if (fns->set_mctrl)
sa1100_pops.set_mctrl = fns->set_mctrl;
sa1100_pops.pm = fns->pm;
sa1100_pops.set_wake = fns->set_wake;
}
void __init sa1100_register_uart(int idx, int port)
{
if (idx >= NR_PORTS) {
printk(KERN_ERR "%s: bad index number %d\n", __func__, idx);
return;
}
switch (port) {
case 1:
sa1100_ports[idx].port.membase = (void __iomem *)&Ser1UTCR0;
sa1100_ports[idx].port.mapbase = _Ser1UTCR0;
sa1100_ports[idx].port.irq = IRQ_Ser1UART;
sa1100_ports[idx].port.flags = UPF_BOOT_AUTOCONF;
break;
case 2:
sa1100_ports[idx].port.membase = (void __iomem *)&Ser2UTCR0;
sa1100_ports[idx].port.mapbase = _Ser2UTCR0;
sa1100_ports[idx].port.irq = IRQ_Ser2ICP;
sa1100_ports[idx].port.flags = UPF_BOOT_AUTOCONF;
break;
case 3:
sa1100_ports[idx].port.membase = (void __iomem *)&Ser3UTCR0;
sa1100_ports[idx].port.mapbase = _Ser3UTCR0;
sa1100_ports[idx].port.irq = IRQ_Ser3UART;
sa1100_ports[idx].port.flags = UPF_BOOT_AUTOCONF;
break;
default:
printk(KERN_ERR "%s: bad port number %d\n", __func__, port);
}
}
#ifdef CONFIG_SERIAL_SA1100_CONSOLE
static void sa1100_console_putchar(struct uart_port *port, int ch)
{
struct sa1100_port *sport = (struct sa1100_port *)port;
while (!(UART_GET_UTSR1(sport) & UTSR1_TNF))
barrier();
UART_PUT_CHAR(sport, ch);
}
/*
* Interrupts are disabled on entering
*/
static void
sa1100_console_write(struct console *co, const char *s, unsigned int count)
{
struct sa1100_port *sport = &sa1100_ports[co->index];
unsigned int old_utcr3, status;
/*
* First, save UTCR3 and then disable interrupts
*/
old_utcr3 = UART_GET_UTCR3(sport);
UART_PUT_UTCR3(sport, (old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE)) |
UTCR3_TXE);
uart_console_write(&sport->port, s, count, sa1100_console_putchar);
/*
* Finally, wait for transmitter to become empty
* and restore UTCR3
*/
do {
status = UART_GET_UTSR1(sport);
} while (status & UTSR1_TBY);
UART_PUT_UTCR3(sport, old_utcr3);
}
/*
* If the port was already initialised (eg, by a boot loader),
* try to determine the current setup.
*/
static void __init
sa1100_console_get_options(struct sa1100_port *sport, int *baud,
int *parity, int *bits)
{
unsigned int utcr3;
utcr3 = UART_GET_UTCR3(sport) & (UTCR3_RXE | UTCR3_TXE);
if (utcr3 == (UTCR3_RXE | UTCR3_TXE)) {
/* ok, the port was enabled */
unsigned int utcr0, quot;
utcr0 = UART_GET_UTCR0(sport);
*parity = 'n';
if (utcr0 & UTCR0_PE) {
if (utcr0 & UTCR0_OES)
*parity = 'e';
else
*parity = 'o';
}
if (utcr0 & UTCR0_DSS)
*bits = 8;
else
*bits = 7;
quot = UART_GET_UTCR2(sport) | UART_GET_UTCR1(sport) << 8;
quot &= 0xfff;
*baud = sport->port.uartclk / (16 * (quot + 1));
}
}
static int __init
sa1100_console_setup(struct console *co, char *options)
{
struct sa1100_port *sport;
int baud = 9600;
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 == -1 || co->index >= NR_PORTS)
co->index = 0;
sport = &sa1100_ports[co->index];
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
sa1100_console_get_options(sport, &baud, &parity, &bits);
return uart_set_options(&sport->port, co, baud, parity, bits, flow);
}
static struct uart_driver sa1100_reg;
static struct console sa1100_console = {
.name = "ttySA",
.write = sa1100_console_write,
.device = uart_console_device,
.setup = sa1100_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &sa1100_reg,
};
static int __init sa1100_rs_console_init(void)
{
sa1100_init_ports();
register_console(&sa1100_console);
return 0;
}
console_initcall(sa1100_rs_console_init);
#define SA1100_CONSOLE &sa1100_console
#else
#define SA1100_CONSOLE NULL
#endif
static struct uart_driver sa1100_reg = {
.owner = THIS_MODULE,
.driver_name = "ttySA",
.dev_name = "ttySA",
.major = SERIAL_SA1100_MAJOR,
.minor = MINOR_START,
.nr = NR_PORTS,
.cons = SA1100_CONSOLE,
};
static int sa1100_serial_suspend(struct platform_device *dev, pm_message_t state)
{
struct sa1100_port *sport = platform_get_drvdata(dev);
if (sport)
uart_suspend_port(&sa1100_reg, &sport->port);
return 0;
}
static int sa1100_serial_resume(struct platform_device *dev)
{
struct sa1100_port *sport = platform_get_drvdata(dev);
if (sport)
uart_resume_port(&sa1100_reg, &sport->port);
return 0;
}
static int sa1100_serial_probe(struct platform_device *dev)
{
struct resource *res = dev->resource;
int i;
for (i = 0; i < dev->num_resources; i++, res++)
if (res->flags & IORESOURCE_MEM)
break;
if (i < dev->num_resources) {
for (i = 0; i < NR_PORTS; i++) {
if (sa1100_ports[i].port.mapbase != res->start)
continue;
sa1100_ports[i].port.dev = &dev->dev;
uart_add_one_port(&sa1100_reg, &sa1100_ports[i].port);
platform_set_drvdata(dev, &sa1100_ports[i]);
break;
}
}
return 0;
}
static int sa1100_serial_remove(struct platform_device *pdev)
{
struct sa1100_port *sport = platform_get_drvdata(pdev);
if (sport)
uart_remove_one_port(&sa1100_reg, &sport->port);
return 0;
}
static struct platform_driver sa11x0_serial_driver = {
.probe = sa1100_serial_probe,
.remove = sa1100_serial_remove,
.suspend = sa1100_serial_suspend,
.resume = sa1100_serial_resume,
.driver = {
.name = "sa11x0-uart",
.owner = THIS_MODULE,
},
};
static int __init sa1100_serial_init(void)
{
int ret;
printk(KERN_INFO "Serial: SA11x0 driver\n");
sa1100_init_ports();
ret = uart_register_driver(&sa1100_reg);
if (ret == 0) {
ret = platform_driver_register(&sa11x0_serial_driver);
if (ret)
uart_unregister_driver(&sa1100_reg);
}
return ret;
}
static void __exit sa1100_serial_exit(void)
{
platform_driver_unregister(&sa11x0_serial_driver);
uart_unregister_driver(&sa1100_reg);
}
module_init(sa1100_serial_init);
module_exit(sa1100_serial_exit);
MODULE_AUTHOR("Deep Blue Solutions Ltd");
MODULE_DESCRIPTION("SA1100 generic serial port driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_SA1100_MAJOR);
MODULE_ALIAS("platform:sa11x0-uart");