kernel-ark/drivers/serial/uart00.c
Russell King b129a8ccd5 [SERIAL] Clean up and fix tty transmission start/stoping
The start_tx and stop_tx methods were passed a flag to indicate
whether the start/stop was from the tty start/stop callbacks, and
some drivers used this flag to decide whether to ask the UART to
immediately stop transmission (where the UART supports such a
feature.)

There are other cases when we wish this to occur - when CTS is
lowered, or if we change from soft to hard flow control and CTS
is inactive.  In these cases, this flag was false, and we would
allow the transmitter to drain before stopping.

There is really only one case where we want to let the transmitter
drain before disabling, and that's when we run out of characters
to send.

Hence, re-jig the start_tx and stop_tx methods to eliminate this
flag, and introduce new functions for the special "disable and
allow transmitter to drain" case.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-08-31 10:12:14 +01:00

783 lines
18 KiB
C

/*
* linux/drivers/serial/uart00.c
*
* Driver for UART00 serial ports
*
* Based on drivers/char/serial_amba.c, by ARM Limited &
* Deep Blue Solutions Ltd.
* Copyright 2001 Altera Corporation
*
* Update for 2.6.4 by Dirk Behme <dirk.behme@de.bosch.com>
*
* 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
*
* $Id: uart00.c,v 1.35 2002/07/28 10:03:28 rmk Exp $
*
*/
#include <linux/config.h>
#if defined(CONFIG_SERIAL_UART00_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/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/sizes.h>
#include <asm/arch/excalibur.h>
#define UART00_TYPE (volatile unsigned int*)
#include <asm/arch/uart00.h>
#include <asm/arch/int_ctrl00.h>
#define UART_NR 2
#define SERIAL_UART00_NAME "ttyUA"
#define SERIAL_UART00_MAJOR 204
#define SERIAL_UART00_MINOR 16 /* Temporary - will change in future */
#define SERIAL_UART00_NR UART_NR
#define UART_PORT_SIZE 0x50
#define UART00_ISR_PASS_LIMIT 256
/*
* Access macros for the UART00 UARTs
*/
#define UART_GET_INT_STATUS(p) inl(UART_ISR((p)->membase))
#define UART_PUT_IES(p, c) outl(c,UART_IES((p)->membase))
#define UART_GET_IES(p) inl(UART_IES((p)->membase))
#define UART_PUT_IEC(p, c) outl(c,UART_IEC((p)->membase))
#define UART_GET_IEC(p) inl(UART_IEC((p)->membase))
#define UART_PUT_CHAR(p, c) outl(c,UART_TD((p)->membase))
#define UART_GET_CHAR(p) inl(UART_RD((p)->membase))
#define UART_GET_RSR(p) inl(UART_RSR((p)->membase))
#define UART_GET_RDS(p) inl(UART_RDS((p)->membase))
#define UART_GET_MSR(p) inl(UART_MSR((p)->membase))
#define UART_GET_MCR(p) inl(UART_MCR((p)->membase))
#define UART_PUT_MCR(p, c) outl(c,UART_MCR((p)->membase))
#define UART_GET_MC(p) inl(UART_MC((p)->membase))
#define UART_PUT_MC(p, c) outl(c,UART_MC((p)->membase))
#define UART_GET_TSR(p) inl(UART_TSR((p)->membase))
#define UART_GET_DIV_HI(p) inl(UART_DIV_HI((p)->membase))
#define UART_PUT_DIV_HI(p,c) outl(c,UART_DIV_HI((p)->membase))
#define UART_GET_DIV_LO(p) inl(UART_DIV_LO((p)->membase))
#define UART_PUT_DIV_LO(p,c) outl(c,UART_DIV_LO((p)->membase))
#define UART_RX_DATA(s) ((s) & UART_RSR_RX_LEVEL_MSK)
#define UART_TX_READY(s) (((s) & UART_TSR_TX_LEVEL_MSK) < 15)
//#define UART_TX_EMPTY(p) ((UART_GET_FR(p) & UART00_UARTFR_TMSK) == 0)
static void uart00_stop_tx(struct uart_port *port)
{
UART_PUT_IEC(port, UART_IEC_TIE_MSK);
}
static void uart00_stop_rx(struct uart_port *port)
{
UART_PUT_IEC(port, UART_IEC_RE_MSK);
}
static void uart00_enable_ms(struct uart_port *port)
{
UART_PUT_IES(port, UART_IES_ME_MSK);
}
static void
uart00_rx_chars(struct uart_port *port, struct pt_regs *regs)
{
struct tty_struct *tty = port->info->tty;
unsigned int status, ch, rds, flg, ignored = 0;
status = UART_GET_RSR(port);
while (UART_RX_DATA(status)) {
/*
* We need to read rds before reading the
* character from the fifo
*/
rds = UART_GET_RDS(port);
ch = UART_GET_CHAR(port);
port->icount.rx++;
if (tty->flip.count >= TTY_FLIPBUF_SIZE)
goto ignore_char;
flg = TTY_NORMAL;
/*
* Note that the error handling code is
* out of the main execution path
*/
if (rds & (UART_RDS_BI_MSK |UART_RDS_FE_MSK|
UART_RDS_PE_MSK |UART_RDS_PE_MSK))
goto handle_error;
if (uart_handle_sysrq_char(port, ch, regs))
goto ignore_char;
error_return:
tty_insert_flip_char(tty, ch, flg);
ignore_char:
status = UART_GET_RSR(port);
}
out:
tty_flip_buffer_push(tty);
return;
handle_error:
if (rds & UART_RDS_BI_MSK) {
status &= ~(UART_RDS_FE_MSK | UART_RDS_PE_MSK);
port->icount.brk++;
if (uart_handle_break(port))
goto ignore_char;
} else if (rds & UART_RDS_PE_MSK)
port->icount.parity++;
else if (rds & UART_RDS_FE_MSK)
port->icount.frame++;
if (rds & UART_RDS_OE_MSK)
port->icount.overrun++;
if (rds & port->ignore_status_mask) {
if (++ignored > 100)
goto out;
goto ignore_char;
}
rds &= port->read_status_mask;
if (rds & UART_RDS_BI_MSK)
flg = TTY_BREAK;
else if (rds & UART_RDS_PE_MSK)
flg = TTY_PARITY;
else if (rds & UART_RDS_FE_MSK)
flg = TTY_FRAME;
if (rds & UART_RDS_OE_MSK) {
/*
* CHECK: does overrun affect the current character?
* ASSUMPTION: it does not.
*/
tty_insert_flip_char(tty, ch, flg);
ch = 0;
flg = TTY_OVERRUN;
}
#ifdef SUPPORT_SYSRQ
port->sysrq = 0;
#endif
goto error_return;
}
static void uart00_tx_chars(struct uart_port *port)
{
struct circ_buf *xmit = &port->info->xmit;
int count;
if (port->x_char) {
while ((UART_GET_TSR(port) & UART_TSR_TX_LEVEL_MSK) == 15)
barrier();
UART_PUT_CHAR(port, port->x_char);
port->icount.tx++;
port->x_char = 0;
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
uart00_stop_tx(port);
return;
}
count = port->fifosize >> 1;
do {
while ((UART_GET_TSR(port) & UART_TSR_TX_LEVEL_MSK) == 15)
barrier();
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;
} while (--count > 0);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (uart_circ_empty(xmit))
uart00_stop_tx(port);
}
static void uart00_start_tx(struct uart_port *port)
{
UART_PUT_IES(port, UART_IES_TIE_MSK);
uart00_tx_chars(port);
}
static void uart00_modem_status(struct uart_port *port)
{
unsigned int status;
status = UART_GET_MSR(port);
if (!(status & (UART_MSR_DCTS_MSK | UART_MSR_DDSR_MSK |
UART_MSR_TERI_MSK | UART_MSR_DDCD_MSK)))
return;
if (status & UART_MSR_DDCD_MSK)
uart_handle_dcd_change(port, status & UART_MSR_DCD_MSK);
if (status & UART_MSR_DDSR_MSK)
port->icount.dsr++;
if (status & UART_MSR_DCTS_MSK)
uart_handle_cts_change(port, status & UART_MSR_CTS_MSK);
wake_up_interruptible(&port->info->delta_msr_wait);
}
static irqreturn_t uart00_int(int irq, void *dev_id, struct pt_regs *regs)
{
struct uart_port *port = dev_id;
unsigned int status, pass_counter = 0;
status = UART_GET_INT_STATUS(port);
do {
if (status & UART_ISR_RI_MSK)
uart00_rx_chars(port, regs);
if (status & UART_ISR_MI_MSK)
uart00_modem_status(port);
if (status & (UART_ISR_TI_MSK | UART_ISR_TII_MSK))
uart00_tx_chars(port);
if (pass_counter++ > UART00_ISR_PASS_LIMIT)
break;
status = UART_GET_INT_STATUS(port);
} while (status);
return IRQ_HANDLED;
}
static unsigned int uart00_tx_empty(struct uart_port *port)
{
return UART_GET_TSR(port) & UART_TSR_TX_LEVEL_MSK? 0 : TIOCSER_TEMT;
}
static unsigned int uart00_get_mctrl(struct uart_port *port)
{
unsigned int result = 0;
unsigned int status;
status = UART_GET_MSR(port);
if (status & UART_MSR_DCD_MSK)
result |= TIOCM_CAR;
if (status & UART_MSR_DSR_MSK)
result |= TIOCM_DSR;
if (status & UART_MSR_CTS_MSK)
result |= TIOCM_CTS;
if (status & UART_MSR_RI_MSK)
result |= TIOCM_RI;
return result;
}
static void uart00_set_mctrl_null(struct uart_port *port, unsigned int mctrl)
{
}
static void uart00_break_ctl(struct uart_port *port, int break_state)
{
unsigned long flags;
unsigned int mcr;
spin_lock_irqsave(&port->lock, flags);
mcr = UART_GET_MCR(port);
if (break_state == -1)
mcr |= UART_MCR_BR_MSK;
else
mcr &= ~UART_MCR_BR_MSK;
UART_PUT_MCR(port, mcr);
spin_unlock_irqrestore(&port->lock, flags);
}
static void
uart00_set_termios(struct uart_port *port, struct termios *termios,
struct termios *old)
{
unsigned int uart_mc, old_ies, baud, quot;
unsigned long flags;
/*
* We don't support CREAD (yet)
*/
termios->c_cflag |= CREAD;
/*
* 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);
/* byte size and parity */
switch (termios->c_cflag & CSIZE) {
case CS5:
uart_mc = UART_MC_CLS_CHARLEN_5;
break;
case CS6:
uart_mc = UART_MC_CLS_CHARLEN_6;
break;
case CS7:
uart_mc = UART_MC_CLS_CHARLEN_7;
break;
default: // CS8
uart_mc = UART_MC_CLS_CHARLEN_8;
break;
}
if (termios->c_cflag & CSTOPB)
uart_mc|= UART_MC_ST_TWO;
if (termios->c_cflag & PARENB) {
uart_mc |= UART_MC_PE_MSK;
if (!(termios->c_cflag & PARODD))
uart_mc |= UART_MC_EP_MSK;
}
spin_lock_irqsave(&port->lock, flags);
/*
* Update the per-port timeout.
*/
uart_update_timeout(port, termios->c_cflag, baud);
port->read_status_mask = UART_RDS_OE_MSK;
if (termios->c_iflag & INPCK)
port->read_status_mask |= UART_RDS_FE_MSK | UART_RDS_PE_MSK;
if (termios->c_iflag & (BRKINT | PARMRK))
port->read_status_mask |= UART_RDS_BI_MSK;
/*
* Characters to ignore
*/
port->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= UART_RDS_FE_MSK | UART_RDS_PE_MSK;
if (termios->c_iflag & IGNBRK) {
port->ignore_status_mask |= UART_RDS_BI_MSK;
/*
* If we're ignoring parity and break indicators,
* ignore overruns to (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= UART_RDS_OE_MSK;
}
/* first, disable everything */
old_ies = UART_GET_IES(port);
if (UART_ENABLE_MS(port, termios->c_cflag))
old_ies |= UART_IES_ME_MSK;
/* Set baud rate */
UART_PUT_DIV_LO(port, (quot & 0xff));
UART_PUT_DIV_HI(port, ((quot & 0xf00) >> 8));
UART_PUT_MC(port, uart_mc);
UART_PUT_IES(port, old_ies);
spin_unlock_irqrestore(&port->lock, flags);
}
static int uart00_startup(struct uart_port *port)
{
int result;
/*
* Allocate the IRQ
*/
result = request_irq(port->irq, uart00_int, 0, "uart00", port);
if (result) {
printk(KERN_ERR "Request of irq %d failed\n", port->irq);
return result;
}
/*
* Finally, enable interrupts. Use the TII interrupt to minimise
* the number of interrupts generated. If higher performance is
* needed, consider using the TI interrupt with a suitable FIFO
* threshold
*/
UART_PUT_IES(port, UART_IES_RE_MSK | UART_IES_TIE_MSK);
return 0;
}
static void uart00_shutdown(struct uart_port *port)
{
/*
* disable all interrupts, disable the port
*/
UART_PUT_IEC(port, 0xff);
/* disable break condition and fifos */
UART_PUT_MCR(port, UART_GET_MCR(port) &~UART_MCR_BR_MSK);
/*
* Free the interrupt
*/
free_irq(port->irq, port);
}
static const char *uart00_type(struct uart_port *port)
{
return port->type == PORT_UART00 ? "Altera UART00" : NULL;
}
/*
* Release the memory region(s) being used by 'port'
*/
static void uart00_release_port(struct uart_port *port)
{
release_mem_region(port->mapbase, UART_PORT_SIZE);
#ifdef CONFIG_ARCH_CAMELOT
if (port->membase != (void*)IO_ADDRESS(EXC_UART00_BASE)) {
iounmap(port->membase);
}
#endif
}
/*
* Request the memory region(s) being used by 'port'
*/
static int uart00_request_port(struct uart_port *port)
{
return request_mem_region(port->mapbase, UART_PORT_SIZE, "serial_uart00")
!= NULL ? 0 : -EBUSY;
}
/*
* Configure/autoconfigure the port.
*/
static void uart00_config_port(struct uart_port *port, int flags)
{
/*
* Map the io memory if this is a soft uart
*/
if (!port->membase)
port->membase = ioremap_nocache(port->mapbase,SZ_4K);
if (!port->membase)
printk(KERN_ERR "serial00: cannot map io memory\n");
else
port->type = PORT_UART00;
}
/*
* verify the new serial_struct (for TIOCSSERIAL).
*/
static int uart00_verify_port(struct uart_port *port, struct serial_struct *ser)
{
int ret = 0;
if (ser->type != PORT_UNKNOWN && ser->type != PORT_UART00)
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 uart00_pops = {
.tx_empty = uart00_tx_empty,
.set_mctrl = uart00_set_mctrl_null,
.get_mctrl = uart00_get_mctrl,
.stop_tx = uart00_stop_tx,
.start_tx = uart00_start_tx,
.stop_rx = uart00_stop_rx,
.enable_ms = uart00_enable_ms,
.break_ctl = uart00_break_ctl,
.startup = uart00_startup,
.shutdown = uart00_shutdown,
.set_termios = uart00_set_termios,
.type = uart00_type,
.release_port = uart00_release_port,
.request_port = uart00_request_port,
.config_port = uart00_config_port,
.verify_port = uart00_verify_port,
};
#ifdef CONFIG_ARCH_CAMELOT
static struct uart_port epxa10db_port = {
.membase = (void*)IO_ADDRESS(EXC_UART00_BASE),
.mapbase = EXC_UART00_BASE,
.iotype = SERIAL_IO_MEM,
.irq = IRQ_UART,
.uartclk = EXC_AHB2_CLK_FREQUENCY,
.fifosize = 16,
.ops = &uart00_pops,
.flags = ASYNC_BOOT_AUTOCONF,
};
#endif
#ifdef CONFIG_SERIAL_UART00_CONSOLE
static void uart00_console_write(struct console *co, const char *s, unsigned count)
{
#ifdef CONFIG_ARCH_CAMELOT
struct uart_port *port = &epxa10db_port;
unsigned int status, old_ies;
int i;
/*
* First save the CR then disable the interrupts
*/
old_ies = UART_GET_IES(port);
UART_PUT_IEC(port,0xff);
/*
* Now, do each character
*/
for (i = 0; i < count; i++) {
do {
status = UART_GET_TSR(port);
} while (!UART_TX_READY(status));
UART_PUT_CHAR(port, s[i]);
if (s[i] == '\n') {
do {
status = UART_GET_TSR(port);
} while (!UART_TX_READY(status));
UART_PUT_CHAR(port, '\r');
}
}
/*
* Finally, wait for transmitter to become empty
* and restore the IES
*/
do {
status = UART_GET_TSR(port);
} while (status & UART_TSR_TX_LEVEL_MSK);
UART_PUT_IES(port, old_ies);
#endif
}
static void __init
uart00_console_get_options(struct uart_port *port, int *baud,
int *parity, int *bits)
{
unsigned int uart_mc, quot;
uart_mc = UART_GET_MC(port);
*parity = 'n';
if (uart_mc & UART_MC_PE_MSK) {
if (uart_mc & UART_MC_EP_MSK)
*parity = 'e';
else
*parity = 'o';
}
switch (uart_mc & UART_MC_CLS_MSK) {
case UART_MC_CLS_CHARLEN_5:
*bits = 5;
break;
case UART_MC_CLS_CHARLEN_6:
*bits = 6;
break;
case UART_MC_CLS_CHARLEN_7:
*bits = 7;
break;
case UART_MC_CLS_CHARLEN_8:
*bits = 8;
break;
}
quot = UART_GET_DIV_LO(port) | (UART_GET_DIV_HI(port) << 8);
*baud = port->uartclk / (16 *quot );
}
static int __init uart00_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
#ifdef CONFIG_ARCH_CAMELOT
port = &epxa10db_port; ;
#else
return -ENODEV;
#endif
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
uart00_console_get_options(port, &baud, &parity, &bits);
return uart_set_options(port, co, baud, parity, bits, flow);
}
extern struct uart_driver uart00_reg;
static struct console uart00_console = {
.name = SERIAL_UART00_NAME,
.write = uart00_console_write,
.device = uart_console_device,
.setup = uart00_console_setup,
.flags = CON_PRINTBUFFER,
.index = 0,
.data = &uart00_reg,
};
static int __init uart00_console_init(void)
{
register_console(&uart00_console);
return 0;
}
console_initcall(uart00_console_init);
#define UART00_CONSOLE &uart00_console
#else
#define UART00_CONSOLE NULL
#endif
static struct uart_driver uart00_reg = {
.owner = NULL,
.driver_name = SERIAL_UART00_NAME,
.dev_name = SERIAL_UART00_NAME,
.major = SERIAL_UART00_MAJOR,
.minor = SERIAL_UART00_MINOR,
.nr = UART_NR,
.cons = UART00_CONSOLE,
};
struct dev_port_entry{
unsigned int base_addr;
struct uart_port *port;
};
#ifdef CONFIG_PLD_HOTSWAP
static struct dev_port_entry dev_port_map[UART_NR];
/*
* Keep a mapping of dev_info addresses -> port lines to use when
* removing ports dev==NULL indicates unused entry
*/
struct uart00_ps_data{
unsigned int clk;
unsigned int fifosize;
};
int uart00_add_device(struct pldhs_dev_info* dev_info, void* dev_ps_data)
{
struct uart00_ps_data* dev_ps=dev_ps_data;
struct uart_port * port;
int i,result;
i=0;
while(dev_port_map[i].port)
i++;
if(i==UART_NR){
printk(KERN_WARNING "uart00: Maximum number of ports reached\n");
return 0;
}
port=kmalloc(sizeof(struct uart_port),GFP_KERNEL);
if(!port)
return -ENOMEM;
printk("clk=%d fifo=%d\n",dev_ps->clk,dev_ps->fifosize);
port->membase=0;
port->mapbase=dev_info->base_addr;
port->iotype=SERIAL_IO_MEM;
port->irq=dev_info->irq;
port->uartclk=dev_ps->clk;
port->fifosize=dev_ps->fifosize;
port->ops=&uart00_pops;
port->line=i;
port->flags=ASYNC_BOOT_AUTOCONF;
result=uart_add_one_port(&uart00_reg, port);
if(result){
printk("uart_add_one_port returned %d\n",result);
return result;
}
dev_port_map[i].base_addr=dev_info->base_addr;
dev_port_map[i].port=port;
printk("uart00: added device at %x as ttyUA%d\n",dev_port_map[i].base_addr,i);
return 0;
}
int uart00_remove_devices(void)
{
int i,result;
result=0;
for(i=1;i<UART_NR;i++){
if(dev_port_map[i].base_addr){
result=uart_remove_one_port(&uart00_reg, dev_port_map[i].port);
if(result)
return result;
/* port removed sucessfully, so now tidy up */
kfree(dev_port_map[i].port);
dev_port_map[i].base_addr=0;
dev_port_map[i].port=NULL;
}
}
return 0;
}
struct pld_hotswap_ops uart00_pldhs_ops={
.name = "uart00",
.add_device = uart00_add_device,
.remove_devices = uart00_remove_devices,
};
#endif
static int __init uart00_init(void)
{
int result;
printk(KERN_INFO "Serial: UART00 driver $Revision: 1.35 $\n");
printk(KERN_WARNING "serial_uart00:Using temporary major/minor pairs"
" - these WILL change in the future\n");
result = uart_register_driver(&uart00_reg);
if (result)
return result;
#ifdef CONFIG_ARCH_CAMELOT
result = uart_add_one_port(&uart00_reg,&epxa10db_port);
#endif
if (result)
uart_unregister_driver(&uart00_reg);
#ifdef CONFIG_PLD_HOTSWAP
pldhs_register_driver(&uart00_pldhs_ops);
#endif
return result;
}
__initcall(uart00_init);