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linux/arch/mn10300/kernel/mn10300-serial.c

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/* MN10300 On-chip serial port UART driver
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
static const char serial_name[] = "MN10300 Serial driver";
static const char serial_version[] = "mn10300_serial-1.0";
static const char serial_revdate[] = "2007-11-06";
#if defined(CONFIG_MN10300_TTYSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/version.h>
#include <linux/module.h>
#include <linux/serial.h>
#include <linux/circ_buf.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/bitops.h>
#include <asm/serial-regs.h>
#include <asm/unit/timex.h>
#include "mn10300-serial.h"
static inline __attribute__((format(printf, 1, 2)))
void no_printk(const char *fmt, ...)
{
}
#define kenter(FMT, ...) \
printk(KERN_DEBUG "-->%s(" FMT ")\n", __func__, ##__VA_ARGS__)
#define _enter(FMT, ...) \
no_printk(KERN_DEBUG "-->%s(" FMT ")\n", __func__, ##__VA_ARGS__)
#define kdebug(FMT, ...) \
printk(KERN_DEBUG "--- " FMT "\n", ##__VA_ARGS__)
#define _debug(FMT, ...) \
no_printk(KERN_DEBUG "--- " FMT "\n", ##__VA_ARGS__)
#define kproto(FMT, ...) \
printk(KERN_DEBUG "### MNSERIAL " FMT " ###\n", ##__VA_ARGS__)
#define _proto(FMT, ...) \
no_printk(KERN_DEBUG "### MNSERIAL " FMT " ###\n", ##__VA_ARGS__)
#define NR_UARTS 3
#ifdef CONFIG_MN10300_TTYSM_CONSOLE
static void mn10300_serial_console_write(struct console *co,
const char *s, unsigned count);
static int __init mn10300_serial_console_setup(struct console *co,
char *options);
static struct uart_driver mn10300_serial_driver;
static struct console mn10300_serial_console = {
.name = "ttySM",
.write = mn10300_serial_console_write,
.device = uart_console_device,
.setup = mn10300_serial_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &mn10300_serial_driver,
};
#endif
static struct uart_driver mn10300_serial_driver = {
.owner = NULL,
.driver_name = "mn10300-serial",
.dev_name = "ttySM",
.major = TTY_MAJOR,
.minor = 128,
.nr = NR_UARTS,
#ifdef CONFIG_MN10300_TTYSM_CONSOLE
.cons = &mn10300_serial_console,
#endif
};
static unsigned int mn10300_serial_tx_empty(struct uart_port *);
static void mn10300_serial_set_mctrl(struct uart_port *, unsigned int mctrl);
static unsigned int mn10300_serial_get_mctrl(struct uart_port *);
static void mn10300_serial_stop_tx(struct uart_port *);
static void mn10300_serial_start_tx(struct uart_port *);
static void mn10300_serial_send_xchar(struct uart_port *, char ch);
static void mn10300_serial_stop_rx(struct uart_port *);
static void mn10300_serial_enable_ms(struct uart_port *);
static void mn10300_serial_break_ctl(struct uart_port *, int ctl);
static int mn10300_serial_startup(struct uart_port *);
static void mn10300_serial_shutdown(struct uart_port *);
static void mn10300_serial_set_termios(struct uart_port *,
struct ktermios *new,
struct ktermios *old);
static const char *mn10300_serial_type(struct uart_port *);
static void mn10300_serial_release_port(struct uart_port *);
static int mn10300_serial_request_port(struct uart_port *);
static void mn10300_serial_config_port(struct uart_port *, int);
static int mn10300_serial_verify_port(struct uart_port *,
struct serial_struct *);
static const struct uart_ops mn10300_serial_ops = {
.tx_empty = mn10300_serial_tx_empty,
.set_mctrl = mn10300_serial_set_mctrl,
.get_mctrl = mn10300_serial_get_mctrl,
.stop_tx = mn10300_serial_stop_tx,
.start_tx = mn10300_serial_start_tx,
.send_xchar = mn10300_serial_send_xchar,
.stop_rx = mn10300_serial_stop_rx,
.enable_ms = mn10300_serial_enable_ms,
.break_ctl = mn10300_serial_break_ctl,
.startup = mn10300_serial_startup,
.shutdown = mn10300_serial_shutdown,
.set_termios = mn10300_serial_set_termios,
.type = mn10300_serial_type,
.release_port = mn10300_serial_release_port,
.request_port = mn10300_serial_request_port,
.config_port = mn10300_serial_config_port,
.verify_port = mn10300_serial_verify_port,
};
static irqreturn_t mn10300_serial_interrupt(int irq, void *dev_id);
/*
* the first on-chip serial port: ttySM0 (aka SIF0)
*/
#ifdef CONFIG_MN10300_TTYSM0
struct mn10300_serial_port mn10300_serial_port_sif0 = {
.uart.ops = &mn10300_serial_ops,
.uart.membase = (void __iomem *) &SC0CTR,
.uart.mapbase = (unsigned long) &SC0CTR,
.uart.iotype = UPIO_MEM,
.uart.irq = 0,
.uart.uartclk = 0, /* MN10300_IOCLK, */
.uart.fifosize = 1,
.uart.flags = UPF_BOOT_AUTOCONF,
.uart.line = 0,
.uart.type = PORT_MN10300,
.uart.lock =
__SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif0.uart.lock),
.name = "ttySM0",
._iobase = &SC0CTR,
._control = &SC0CTR,
._status = (volatile u8 *) &SC0STR,
._intr = &SC0ICR,
._rxb = &SC0RXB,
._txb = &SC0TXB,
.rx_name = "ttySM0/Rx",
.tx_name = "ttySM0/Tx",
#ifdef CONFIG_MN10300_TTYSM0_TIMER8
.tm_name = "ttySM0/Timer8",
._tmxmd = &TM8MD,
._tmxbr = &TM8BR,
._tmicr = &TM8ICR,
.tm_irq = TM8IRQ,
.div_timer = MNSCx_DIV_TIMER_16BIT,
#else /* CONFIG_MN10300_TTYSM0_TIMER2 */
.tm_name = "ttySM0/Timer2",
._tmxmd = &TM2MD,
._tmxbr = (volatile u16 *) &TM2BR,
._tmicr = &TM2ICR,
.tm_irq = TM2IRQ,
.div_timer = MNSCx_DIV_TIMER_8BIT,
#endif
.rx_irq = SC0RXIRQ,
.tx_irq = SC0TXIRQ,
.rx_icr = &GxICR(SC0RXIRQ),
.tx_icr = &GxICR(SC0TXIRQ),
.clock_src = MNSCx_CLOCK_SRC_IOCLK,
.options = 0,
#ifdef CONFIG_GDBSTUB_ON_TTYSM0
.gdbstub = 1,
#endif
};
#endif /* CONFIG_MN10300_TTYSM0 */
/*
* the second on-chip serial port: ttySM1 (aka SIF1)
*/
#ifdef CONFIG_MN10300_TTYSM1
struct mn10300_serial_port mn10300_serial_port_sif1 = {
.uart.ops = &mn10300_serial_ops,
.uart.membase = (void __iomem *) &SC1CTR,
.uart.mapbase = (unsigned long) &SC1CTR,
.uart.iotype = UPIO_MEM,
.uart.irq = 0,
.uart.uartclk = 0, /* MN10300_IOCLK, */
.uart.fifosize = 1,
.uart.flags = UPF_BOOT_AUTOCONF,
.uart.line = 1,
.uart.type = PORT_MN10300,
.uart.lock =
__SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif1.uart.lock),
.name = "ttySM1",
._iobase = &SC1CTR,
._control = &SC1CTR,
._status = (volatile u8 *) &SC1STR,
._intr = &SC1ICR,
._rxb = &SC1RXB,
._txb = &SC1TXB,
.rx_name = "ttySM1/Rx",
.tx_name = "ttySM1/Tx",
#ifdef CONFIG_MN10300_TTYSM1_TIMER9
.tm_name = "ttySM1/Timer9",
._tmxmd = &TM9MD,
._tmxbr = &TM9BR,
._tmicr = &TM9ICR,
.tm_irq = TM9IRQ,
.div_timer = MNSCx_DIV_TIMER_16BIT,
#else /* CONFIG_MN10300_TTYSM1_TIMER3 */
.tm_name = "ttySM1/Timer3",
._tmxmd = &TM3MD,
._tmxbr = (volatile u16 *) &TM3BR,
._tmicr = &TM3ICR,
.tm_irq = TM3IRQ,
.div_timer = MNSCx_DIV_TIMER_8BIT,
#endif
.rx_irq = SC1RXIRQ,
.tx_irq = SC1TXIRQ,
.rx_icr = &GxICR(SC1RXIRQ),
.tx_icr = &GxICR(SC1TXIRQ),
.clock_src = MNSCx_CLOCK_SRC_IOCLK,
.options = 0,
#ifdef CONFIG_GDBSTUB_ON_TTYSM1
.gdbstub = 1,
#endif
};
#endif /* CONFIG_MN10300_TTYSM1 */
/*
* the third on-chip serial port: ttySM2 (aka SIF2)
*/
#ifdef CONFIG_MN10300_TTYSM2
struct mn10300_serial_port mn10300_serial_port_sif2 = {
.uart.ops = &mn10300_serial_ops,
.uart.membase = (void __iomem *) &SC2CTR,
.uart.mapbase = (unsigned long) &SC2CTR,
.uart.iotype = UPIO_MEM,
.uart.irq = 0,
.uart.uartclk = 0, /* MN10300_IOCLK, */
.uart.fifosize = 1,
.uart.flags = UPF_BOOT_AUTOCONF,
.uart.line = 2,
#ifdef CONFIG_MN10300_TTYSM2_CTS
.uart.type = PORT_MN10300_CTS,
#else
.uart.type = PORT_MN10300,
#endif
.uart.lock =
__SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif2.uart.lock),
.name = "ttySM2",
.rx_name = "ttySM2/Rx",
.tx_name = "ttySM2/Tx",
.tm_name = "ttySM2/Timer10",
._iobase = &SC2CTR,
._control = &SC2CTR,
._status = &SC2STR,
._intr = &SC2ICR,
._rxb = &SC2RXB,
._txb = &SC2TXB,
._tmxmd = &TM10MD,
._tmxbr = &TM10BR,
._tmicr = &TM10ICR,
.tm_irq = TM10IRQ,
.div_timer = MNSCx_DIV_TIMER_16BIT,
.rx_irq = SC2RXIRQ,
.tx_irq = SC2TXIRQ,
.rx_icr = &GxICR(SC2RXIRQ),
.tx_icr = &GxICR(SC2TXIRQ),
.clock_src = MNSCx_CLOCK_SRC_IOCLK,
#ifdef CONFIG_MN10300_TTYSM2_CTS
.options = MNSCx_OPT_CTS,
#else
.options = 0,
#endif
#ifdef CONFIG_GDBSTUB_ON_TTYSM2
.gdbstub = 1,
#endif
};
#endif /* CONFIG_MN10300_TTYSM2 */
/*
* list of available serial ports
*/
struct mn10300_serial_port *mn10300_serial_ports[NR_UARTS + 1] = {
#ifdef CONFIG_MN10300_TTYSM0
[0] = &mn10300_serial_port_sif0,
#endif
#ifdef CONFIG_MN10300_TTYSM1
[1] = &mn10300_serial_port_sif1,
#endif
#ifdef CONFIG_MN10300_TTYSM2
[2] = &mn10300_serial_port_sif2,
#endif
[NR_UARTS] = NULL,
};
/*
* we abuse the serial ports' baud timers' interrupt lines to get the ability
* to deliver interrupts to userspace as we use the ports' interrupt lines to
* do virtual DMA on account of the ports having no hardware FIFOs
*
* we can generate an interrupt manually in the assembly stubs by writing to
* the enable and detect bits in the interrupt control register, so all we need
* to do here is disable the interrupt line
*
* note that we can't just leave the line enabled as the baud rate timer *also*
* generates interrupts
*/
static void mn10300_serial_mask_ack(unsigned int irq)
{
u16 tmp;
GxICR(irq) = GxICR_LEVEL_6;
tmp = GxICR(irq); /* flush write buffer */
}
static void mn10300_serial_nop(unsigned int irq)
{
}
static struct irq_chip mn10300_serial_pic = {
.name = "mnserial",
.ack = mn10300_serial_mask_ack,
.mask = mn10300_serial_mask_ack,
.mask_ack = mn10300_serial_mask_ack,
.unmask = mn10300_serial_nop,
.end = mn10300_serial_nop,
};
/*
* serial virtual DMA interrupt jump table
*/
struct mn10300_serial_int mn10300_serial_int_tbl[NR_IRQS];
static void mn10300_serial_dis_tx_intr(struct mn10300_serial_port *port)
{
u16 x;
*port->tx_icr = GxICR_LEVEL_1 | GxICR_DETECT;
x = *port->tx_icr;
}
static void mn10300_serial_en_tx_intr(struct mn10300_serial_port *port)
{
u16 x;
*port->tx_icr = GxICR_LEVEL_1 | GxICR_ENABLE;
x = *port->tx_icr;
}
static void mn10300_serial_dis_rx_intr(struct mn10300_serial_port *port)
{
u16 x;
*port->rx_icr = GxICR_LEVEL_1 | GxICR_DETECT;
x = *port->rx_icr;
}
/*
* multi-bit equivalent of test_and_clear_bit()
*/
static int mask_test_and_clear(volatile u8 *ptr, u8 mask)
{
u32 epsw;
asm volatile(" bclr %1,(%2) \n"
" mov epsw,%0 \n"
: "=d"(epsw) : "d"(mask), "a"(ptr));
return !(epsw & EPSW_FLAG_Z);
}
/*
* receive chars from the ring buffer for this serial port
* - must do break detection here (not done in the UART)
*/
static void mn10300_serial_receive_interrupt(struct mn10300_serial_port *port)
{
struct uart_icount *icount = &port->uart.icount;
struct tty_struct *tty = port->uart.info->port.tty;
unsigned ix;
int count;
u8 st, ch, push, status, overrun;
_enter("%s", port->name);
push = 0;
count = CIRC_CNT(port->rx_inp, port->rx_outp, MNSC_BUFFER_SIZE);
count = tty_buffer_request_room(tty, count);
if (count == 0) {
if (!tty->low_latency)
tty_flip_buffer_push(tty);
return;
}
try_again:
/* pull chars out of the hat */
ix = port->rx_outp;
if (ix == port->rx_inp) {
if (push && !tty->low_latency)
tty_flip_buffer_push(tty);
return;
}
ch = port->rx_buffer[ix++];
st = port->rx_buffer[ix++];
smp_rmb();
port->rx_outp = ix & (MNSC_BUFFER_SIZE - 1);
port->uart.icount.rx++;
st &= SC01STR_FEF | SC01STR_PEF | SC01STR_OEF;
status = 0;
overrun = 0;
/* the UART doesn't detect BREAK, so we have to do that ourselves
* - it starts as a framing error on a NUL character
* - then we count another two NUL characters before issuing TTY_BREAK
* - then we end on a normal char or one that has all the bottom bits
* zero and the top bits set
*/
switch (port->rx_brk) {
case 0:
/* not breaking at the moment */
break;
case 1:
if (st & SC01STR_FEF && ch == 0) {
port->rx_brk = 2;
goto try_again;
}
goto not_break;
case 2:
if (st & SC01STR_FEF && ch == 0) {
port->rx_brk = 3;
_proto("Rx Break Detected");
icount->brk++;
if (uart_handle_break(&port->uart))
goto ignore_char;
status |= 1 << TTY_BREAK;
goto insert;
}
goto not_break;
default:
if (st & (SC01STR_FEF | SC01STR_PEF | SC01STR_OEF))
goto try_again; /* still breaking */
port->rx_brk = 0; /* end of the break */
switch (ch) {
case 0xFF:
case 0xFE:
case 0xFC:
case 0xF8:
case 0xF0:
case 0xE0:
case 0xC0:
case 0x80:
case 0x00:
/* discard char at probable break end */
goto try_again;
}
break;
}
process_errors:
/* handle framing error */
if (st & SC01STR_FEF) {
if (ch == 0) {
/* framing error with NUL char is probably a BREAK */
port->rx_brk = 1;
goto try_again;
}
_proto("Rx Framing Error");
icount->frame++;
status |= 1 << TTY_FRAME;
}
/* handle parity error */
if (st & SC01STR_PEF) {
_proto("Rx Parity Error");
icount->parity++;
status = TTY_PARITY;
}
/* handle normal char */
if (status == 0) {
if (uart_handle_sysrq_char(&port->uart, ch))
goto ignore_char;
status = (1 << TTY_NORMAL);
}
/* handle overrun error */
if (st & SC01STR_OEF) {
if (port->rx_brk)
goto try_again;
_proto("Rx Overrun Error");
icount->overrun++;
overrun = 1;
}
insert:
status &= port->uart.read_status_mask;
if (!overrun && !(status & port->uart.ignore_status_mask)) {
int flag;
if (status & (1 << TTY_BREAK))
flag = TTY_BREAK;
else if (status & (1 << TTY_PARITY))
flag = TTY_PARITY;
else if (status & (1 << TTY_FRAME))
flag = TTY_FRAME;
else
flag = TTY_NORMAL;
tty_insert_flip_char(tty, ch, flag);
}
/* overrun is special, since it's reported immediately, and doesn't
* affect the current character
*/
if (overrun)
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
count--;
if (count <= 0) {
if (!tty->low_latency)
tty_flip_buffer_push(tty);
return;
}
ignore_char:
push = 1;
goto try_again;
not_break:
port->rx_brk = 0;
goto process_errors;
}
/*
* handle an interrupt from the serial transmission "virtual DMA" driver
* - note: the interrupt routine will disable its own interrupts when the Tx
* buffer is empty
*/
static void mn10300_serial_transmit_interrupt(struct mn10300_serial_port *port)
{
_enter("%s", port->name);
if (uart_tx_stopped(&port->uart) ||
uart_circ_empty(&port->uart.info->xmit))
mn10300_serial_dis_tx_intr(port);
if (uart_circ_chars_pending(&port->uart.info->xmit) < WAKEUP_CHARS)
uart_write_wakeup(&port->uart);
}
/*
* deal with a change in the status of the CTS line
*/
static void mn10300_serial_cts_changed(struct mn10300_serial_port *port, u8 st)
{
u16 ctr;
port->tx_cts = st;
port->uart.icount.cts++;
/* flip the CTS state selector flag to interrupt when it changes
* back */
ctr = *port->_control;
ctr ^= SC2CTR_TWS;
*port->_control = ctr;
uart_handle_cts_change(&port->uart, st & SC2STR_CTS);
wake_up_interruptible(&port->uart.info->delta_msr_wait);
}
/*
* handle a virtual interrupt generated by the lower level "virtual DMA"
* routines (irq is the baud timer interrupt)
*/
static irqreturn_t mn10300_serial_interrupt(int irq, void *dev_id)
{
struct mn10300_serial_port *port = dev_id;
u8 st;
spin_lock(&port->uart.lock);
if (port->intr_flags) {
_debug("INT %s: %x", port->name, port->intr_flags);
if (mask_test_and_clear(&port->intr_flags, MNSCx_RX_AVAIL))
mn10300_serial_receive_interrupt(port);
if (mask_test_and_clear(&port->intr_flags,
MNSCx_TX_SPACE | MNSCx_TX_EMPTY))
mn10300_serial_transmit_interrupt(port);
}
/* the only modem control line amongst the whole lot is CTS on
* serial port 2 */
if (port->type == PORT_MN10300_CTS) {
st = *port->_status;
if ((port->tx_cts ^ st) & SC2STR_CTS)
mn10300_serial_cts_changed(port, st);
}
spin_unlock(&port->uart.lock);
return IRQ_HANDLED;
}
/*
* return indication of whether the hardware transmit buffer is empty
*/
static unsigned int mn10300_serial_tx_empty(struct uart_port *_port)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s", port->name);
return (*port->_status & (SC01STR_TXF | SC01STR_TBF)) ?
0 : TIOCSER_TEMT;
}
/*
* set the modem control lines (we don't have any)
*/
static void mn10300_serial_set_mctrl(struct uart_port *_port,
unsigned int mctrl)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s,%x", port->name, mctrl);
}
/*
* get the modem control line statuses
*/
static unsigned int mn10300_serial_get_mctrl(struct uart_port *_port)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s", port->name);
if (port->type == PORT_MN10300_CTS && !(*port->_status & SC2STR_CTS))
return TIOCM_CAR | TIOCM_DSR;
return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR;
}
/*
* stop transmitting characters
*/
static void mn10300_serial_stop_tx(struct uart_port *_port)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s", port->name);
/* disable the virtual DMA */
mn10300_serial_dis_tx_intr(port);
}
/*
* start transmitting characters
* - jump-start transmission if it has stalled
* - enable the serial Tx interrupt (used by the virtual DMA controller)
* - force an interrupt to happen if necessary
*/
static void mn10300_serial_start_tx(struct uart_port *_port)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
u16 x;
_enter("%s{%lu}",
port->name,
CIRC_CNT(&port->uart.info->xmit.head,
&port->uart.info->xmit.tail,
UART_XMIT_SIZE));
/* kick the virtual DMA controller */
x = *port->tx_icr;
x |= GxICR_ENABLE;
if (*port->_status & SC01STR_TBF)
x &= ~(GxICR_REQUEST | GxICR_DETECT);
else
x |= GxICR_REQUEST | GxICR_DETECT;
_debug("CTR=%04hx ICR=%02hx STR=%04x TMD=%02hx TBR=%04hx ICR=%04hx",
*port->_control, *port->_intr, *port->_status,
*port->_tmxmd, *port->_tmxbr, *port->tx_icr);
*port->tx_icr = x;
x = *port->tx_icr;
}
/*
* transmit a high-priority XON/XOFF character
*/
static void mn10300_serial_send_xchar(struct uart_port *_port, char ch)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s,%02x", port->name, ch);
if (likely(port->gdbstub)) {
port->tx_xchar = ch;
if (ch)
mn10300_serial_en_tx_intr(port);
}
}
/*
* stop receiving characters
* - called whilst the port is being closed
*/
static void mn10300_serial_stop_rx(struct uart_port *_port)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
u16 ctr;
_enter("%s", port->name);
ctr = *port->_control;
ctr &= ~SC01CTR_RXE;
*port->_control = ctr;
mn10300_serial_dis_rx_intr(port);
}
/*
* enable modem status interrupts
*/
static void mn10300_serial_enable_ms(struct uart_port *_port)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
u16 ctr, cts;
_enter("%s", port->name);
if (port->type == PORT_MN10300_CTS) {
/* want to interrupt when CTS goes low if CTS is now high and
* vice versa
*/
port->tx_cts = *port->_status;
cts = (port->tx_cts & SC2STR_CTS) ?
SC2CTR_TWE : SC2CTR_TWE | SC2CTR_TWS;
ctr = *port->_control;
ctr &= ~SC2CTR_TWS;
ctr |= cts;
*port->_control = ctr;
mn10300_serial_en_tx_intr(port);
}
}
/*
* transmit or cease transmitting a break signal
*/
static void mn10300_serial_break_ctl(struct uart_port *_port, int ctl)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s,%d", port->name, ctl);
if (ctl) {
/* tell the virtual DMA handler to assert BREAK */
port->tx_break = 1;
mn10300_serial_en_tx_intr(port);
} else {
port->tx_break = 0;
*port->_control &= ~SC01CTR_BKE;
mn10300_serial_en_tx_intr(port);
}
}
/*
* grab the interrupts and enable the port for reception
*/
static int mn10300_serial_startup(struct uart_port *_port)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
struct mn10300_serial_int *pint;
_enter("%s{%d}", port->name, port->gdbstub);
if (unlikely(port->gdbstub))
return -EBUSY;
/* allocate an Rx buffer for the virtual DMA handler */
port->rx_buffer = kmalloc(MNSC_BUFFER_SIZE, GFP_KERNEL);
if (!port->rx_buffer)
return -ENOMEM;
port->rx_inp = port->rx_outp = 0;
/* finally, enable the device */
*port->_intr = SC01ICR_TI;
*port->_control |= SC01CTR_TXE | SC01CTR_RXE;
pint = &mn10300_serial_int_tbl[port->rx_irq];
pint->port = port;
pint->vdma = mn10300_serial_vdma_rx_handler;
pint = &mn10300_serial_int_tbl[port->tx_irq];
pint->port = port;
pint->vdma = mn10300_serial_vdma_tx_handler;
set_intr_level(port->rx_irq, GxICR_LEVEL_1);
set_intr_level(port->tx_irq, GxICR_LEVEL_1);
set_irq_chip(port->tm_irq, &mn10300_serial_pic);
if (request_irq(port->rx_irq, mn10300_serial_interrupt,
IRQF_DISABLED, port->rx_name, port) < 0)
goto error;
if (request_irq(port->tx_irq, mn10300_serial_interrupt,
IRQF_DISABLED, port->tx_name, port) < 0)
goto error2;
if (request_irq(port->tm_irq, mn10300_serial_interrupt,
IRQF_DISABLED, port->tm_name, port) < 0)
goto error3;
mn10300_serial_mask_ack(port->tm_irq);
return 0;
error3:
free_irq(port->tx_irq, port);
error2:
free_irq(port->rx_irq, port);
error:
kfree(port->rx_buffer);
port->rx_buffer = NULL;
return -EBUSY;
}
/*
* shutdown the port and release interrupts
*/
static void mn10300_serial_shutdown(struct uart_port *_port)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s", port->name);
/* disable the serial port and its baud rate timer */
port->tx_break = 0;
*port->_control &= ~(SC01CTR_TXE | SC01CTR_RXE | SC01CTR_BKE);
*port->_tmxmd = 0;
if (port->rx_buffer) {
void *buf = port->rx_buffer;
port->rx_buffer = NULL;
kfree(buf);
}
/* disable all intrs */
free_irq(port->tm_irq, port);
free_irq(port->rx_irq, port);
free_irq(port->tx_irq, port);
*port->rx_icr = GxICR_LEVEL_1;
*port->tx_icr = GxICR_LEVEL_1;
}
/*
* this routine is called to set the UART divisor registers to match the
* specified baud rate for a serial port.
*/
static void mn10300_serial_change_speed(struct mn10300_serial_port *port,
struct ktermios *new,
struct ktermios *old)
{
unsigned long flags;
unsigned long ioclk = port->ioclk;
unsigned cflag;
int baud, bits, xdiv, tmp;
u16 tmxbr, scxctr;
u8 tmxmd, battempt;
u8 div_timer = port->div_timer;
_enter("%s{%lu}", port->name, ioclk);
/* byte size and parity */
cflag = new->c_cflag;
switch (cflag & CSIZE) {
case CS7: scxctr = SC01CTR_CLN_7BIT; bits = 9; break;
case CS8: scxctr = SC01CTR_CLN_8BIT; bits = 10; break;
default: scxctr = SC01CTR_CLN_8BIT; bits = 10; break;
}
if (cflag & CSTOPB) {
scxctr |= SC01CTR_STB_2BIT;
bits++;
}
if (cflag & PARENB) {
bits++;
if (cflag & PARODD)
scxctr |= SC01CTR_PB_ODD;
#ifdef CMSPAR
else if (cflag & CMSPAR)
scxctr |= SC01CTR_PB_FIXED0;
#endif
else
scxctr |= SC01CTR_PB_EVEN;
}
/* Determine divisor based on baud rate */
battempt = 0;
if (div_timer == MNSCx_DIV_TIMER_16BIT)
scxctr |= SC0CTR_CK_TM8UFLOW_8; /* ( == SC1CTR_CK_TM9UFLOW_8
* == SC2CTR_CK_TM10UFLOW) */
else if (div_timer == MNSCx_DIV_TIMER_8BIT)
scxctr |= SC0CTR_CK_TM2UFLOW_8;
try_alternative:
baud = uart_get_baud_rate(&port->uart, new, old, 0,
port->ioclk / 8);
_debug("ALT %d [baud %d]", battempt, baud);
if (!baud)
baud = 9600; /* B0 transition handled in rs_set_termios */
xdiv = 1;
if (baud == 134) {
baud = 269; /* 134 is really 134.5 */
xdiv = 2;
}
if (baud == 38400 &&
(port->uart.flags & UPF_SPD_MASK) == UPF_SPD_CUST
) {
_debug("CUSTOM %u", port->uart.custom_divisor);
if (div_timer == MNSCx_DIV_TIMER_16BIT) {
if (port->uart.custom_divisor <= 65535) {
tmxmd = TM8MD_SRC_IOCLK;
tmxbr = port->uart.custom_divisor;
port->uart.uartclk = ioclk;
goto timer_okay;
}
if (port->uart.custom_divisor / 8 <= 65535) {
tmxmd = TM8MD_SRC_IOCLK_8;
tmxbr = port->uart.custom_divisor / 8;
port->uart.custom_divisor = tmxbr * 8;
port->uart.uartclk = ioclk / 8;
goto timer_okay;
}
if (port->uart.custom_divisor / 32 <= 65535) {
tmxmd = TM8MD_SRC_IOCLK_32;
tmxbr = port->uart.custom_divisor / 32;
port->uart.custom_divisor = tmxbr * 32;
port->uart.uartclk = ioclk / 32;
goto timer_okay;
}
} else if (div_timer == MNSCx_DIV_TIMER_8BIT) {
if (port->uart.custom_divisor <= 255) {
tmxmd = TM2MD_SRC_IOCLK;
tmxbr = port->uart.custom_divisor;
port->uart.uartclk = ioclk;
goto timer_okay;
}
if (port->uart.custom_divisor / 8 <= 255) {
tmxmd = TM2MD_SRC_IOCLK_8;
tmxbr = port->uart.custom_divisor / 8;
port->uart.custom_divisor = tmxbr * 8;
port->uart.uartclk = ioclk / 8;
goto timer_okay;
}
if (port->uart.custom_divisor / 32 <= 255) {
tmxmd = TM2MD_SRC_IOCLK_32;
tmxbr = port->uart.custom_divisor / 32;
port->uart.custom_divisor = tmxbr * 32;
port->uart.uartclk = ioclk / 32;
goto timer_okay;
}
}
}
switch (div_timer) {
case MNSCx_DIV_TIMER_16BIT:
port->uart.uartclk = ioclk;
tmxmd = TM8MD_SRC_IOCLK;
tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
if (tmp > 0 && tmp <= 65535)
goto timer_okay;
port->uart.uartclk = ioclk / 8;
tmxmd = TM8MD_SRC_IOCLK_8;
tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
if (tmp > 0 && tmp <= 65535)
goto timer_okay;
port->uart.uartclk = ioclk / 32;
tmxmd = TM8MD_SRC_IOCLK_32;
tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
if (tmp > 0 && tmp <= 65535)
goto timer_okay;
break;
case MNSCx_DIV_TIMER_8BIT:
port->uart.uartclk = ioclk;
tmxmd = TM2MD_SRC_IOCLK;
tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
if (tmp > 0 && tmp <= 255)
goto timer_okay;
port->uart.uartclk = ioclk / 8;
tmxmd = TM2MD_SRC_IOCLK_8;
tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
if (tmp > 0 && tmp <= 255)
goto timer_okay;
port->uart.uartclk = ioclk / 32;
tmxmd = TM2MD_SRC_IOCLK_32;
tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
if (tmp > 0 && tmp <= 255)
goto timer_okay;
break;
default:
BUG();
return;
}
/* refuse to change to a baud rate we can't support */
_debug("CAN'T SUPPORT");
switch (battempt) {
case 0:
if (old) {
new->c_cflag &= ~CBAUD;
new->c_cflag |= (old->c_cflag & CBAUD);
battempt = 1;
goto try_alternative;
}
case 1:
/* as a last resort, if the quotient is zero, default to 9600
* bps */
new->c_cflag &= ~CBAUD;
new->c_cflag |= B9600;
battempt = 2;
goto try_alternative;
default:
/* hmmm... can't seem to support 9600 either
* - we could try iterating through the speeds we know about to
* find the lowest
*/
new->c_cflag &= ~CBAUD;
new->c_cflag |= B0;
if (div_timer == MNSCx_DIV_TIMER_16BIT)
tmxmd = TM8MD_SRC_IOCLK_32;
else if (div_timer == MNSCx_DIV_TIMER_8BIT)
tmxmd = TM2MD_SRC_IOCLK_32;
tmxbr = 1;
port->uart.uartclk = ioclk / 32;
break;
}
timer_okay:
_debug("UARTCLK: %u / %hu", port->uart.uartclk, tmxbr);
/* make the changes */
spin_lock_irqsave(&port->uart.lock, flags);
uart_update_timeout(&port->uart, new->c_cflag, baud);
/* set the timer to produce the required baud rate */
switch (div_timer) {
case MNSCx_DIV_TIMER_16BIT:
*port->_tmxmd = 0;
*port->_tmxbr = tmxbr;
*port->_tmxmd = TM8MD_INIT_COUNTER;
*port->_tmxmd = tmxmd | TM8MD_COUNT_ENABLE;
break;
case MNSCx_DIV_TIMER_8BIT:
*port->_tmxmd = 0;
*(volatile u8 *) port->_tmxbr = (u8) tmxbr;
*port->_tmxmd = TM2MD_INIT_COUNTER;
*port->_tmxmd = tmxmd | TM2MD_COUNT_ENABLE;
break;
}
/* CTS flow control flag and modem status interrupts */
scxctr &= ~(SC2CTR_TWE | SC2CTR_TWS);
if (port->type == PORT_MN10300_CTS && cflag & CRTSCTS) {
/* want to interrupt when CTS goes low if CTS is now
* high and vice versa
*/
port->tx_cts = *port->_status;
if (port->tx_cts & SC2STR_CTS)
scxctr |= SC2CTR_TWE;
else
scxctr |= SC2CTR_TWE | SC2CTR_TWS;
}
/* set up parity check flag */
port->uart.read_status_mask = (1 << TTY_NORMAL) | (1 << TTY_OVERRUN);
if (new->c_iflag & INPCK)
port->uart.read_status_mask |=
(1 << TTY_PARITY) | (1 << TTY_FRAME);
if (new->c_iflag & (BRKINT | PARMRK))
port->uart.read_status_mask |= (1 << TTY_BREAK);
/* characters to ignore */
port->uart.ignore_status_mask = 0;
if (new->c_iflag & IGNPAR)
port->uart.ignore_status_mask |=
(1 << TTY_PARITY) | (1 << TTY_FRAME);
if (new->c_iflag & IGNBRK) {
port->uart.ignore_status_mask |= (1 << TTY_BREAK);
/*
* If we're ignoring parity and break indicators,
* ignore overruns to (for real raw support).
*/
if (new->c_iflag & IGNPAR)
port->uart.ignore_status_mask |= (1 << TTY_OVERRUN);
}
/* Ignore all characters if CREAD is not set */
if ((new->c_cflag & CREAD) == 0)
port->uart.ignore_status_mask |= (1 << TTY_NORMAL);
scxctr |= *port->_control & (SC01CTR_TXE | SC01CTR_RXE | SC01CTR_BKE);
*port->_control = scxctr;
spin_unlock_irqrestore(&port->uart.lock, flags);
}
/*
* set the terminal I/O parameters
*/
static void mn10300_serial_set_termios(struct uart_port *_port,
struct ktermios *new,
struct ktermios *old)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s,%p,%p", port->name, new, old);
mn10300_serial_change_speed(port, new, old);
/* handle turning off CRTSCTS */
if (!(new->c_cflag & CRTSCTS)) {
u16 ctr = *port->_control;
ctr &= ~SC2CTR_TWE;
*port->_control = ctr;
}
}
/*
* return description of port type
*/
static const char *mn10300_serial_type(struct uart_port *_port)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
if (port->uart.type == PORT_MN10300_CTS)
return "MN10300 SIF_CTS";
return "MN10300 SIF";
}
/*
* release I/O and memory regions in use by port
*/
static void mn10300_serial_release_port(struct uart_port *_port)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s", port->name);
release_mem_region((unsigned long) port->_iobase, 16);
}
/*
* request I/O and memory regions for port
*/
static int mn10300_serial_request_port(struct uart_port *_port)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s", port->name);
request_mem_region((unsigned long) port->_iobase, 16, port->name);
return 0;
}
/*
* configure the type and reserve the ports
*/
static void mn10300_serial_config_port(struct uart_port *_port, int type)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s", port->name);
port->uart.type = PORT_MN10300;
if (port->options & MNSCx_OPT_CTS)
port->uart.type = PORT_MN10300_CTS;
mn10300_serial_request_port(_port);
}
/*
* verify serial parameters are suitable for this port type
*/
static int mn10300_serial_verify_port(struct uart_port *_port,
struct serial_struct *ss)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
void *mapbase = (void *) (unsigned long) port->uart.mapbase;
_enter("%s", port->name);
/* these things may not be changed */
if (ss->irq != port->uart.irq ||
ss->port != port->uart.iobase ||
ss->io_type != port->uart.iotype ||
ss->iomem_base != mapbase ||
ss->iomem_reg_shift != port->uart.regshift ||
ss->hub6 != port->uart.hub6 ||
ss->xmit_fifo_size != port->uart.fifosize)
return -EINVAL;
/* type may be changed on a port that supports CTS */
if (ss->type != port->uart.type) {
if (!(port->options & MNSCx_OPT_CTS))
return -EINVAL;
if (ss->type != PORT_MN10300 &&
ss->type != PORT_MN10300_CTS)
return -EINVAL;
}
return 0;
}
/*
* initialise the MN10300 on-chip UARTs
*/
static int __init mn10300_serial_init(void)
{
struct mn10300_serial_port *port;
int ret, i;
printk(KERN_INFO "%s version %s (%s)\n",
serial_name, serial_version, serial_revdate);
#ifdef CONFIG_MN10300_TTYSM2
SC2TIM = 8; /* make the baud base of timer 2 IOCLK/8 */
#endif
set_intr_stub(EXCEP_IRQ_LEVEL1, mn10300_serial_vdma_interrupt);
ret = uart_register_driver(&mn10300_serial_driver);
if (!ret) {
for (i = 0 ; i < NR_PORTS ; i++) {
port = mn10300_serial_ports[i];
if (!port || port->gdbstub)
continue;
switch (port->clock_src) {
case MNSCx_CLOCK_SRC_IOCLK:
port->ioclk = MN10300_IOCLK;
break;
#ifdef MN10300_IOBCLK
case MNSCx_CLOCK_SRC_IOBCLK:
port->ioclk = MN10300_IOBCLK;
break;
#endif
default:
BUG();
}
ret = uart_add_one_port(&mn10300_serial_driver,
&port->uart);
if (ret < 0) {
_debug("ERROR %d", -ret);
break;
}
}
if (ret)
uart_unregister_driver(&mn10300_serial_driver);
}
return ret;
}
__initcall(mn10300_serial_init);
#ifdef CONFIG_MN10300_TTYSM_CONSOLE
/*
* print a string to the serial port without disturbing the real user of the
* port too much
* - the console must be locked by the caller
*/
static void mn10300_serial_console_write(struct console *co,
const char *s, unsigned count)
{
struct mn10300_serial_port *port;
unsigned i;
u16 scxctr, txicr, tmp;
u8 tmxmd;
port = mn10300_serial_ports[co->index];
/* firstly hijack the serial port from the "virtual DMA" controller */
txicr = *port->tx_icr;
*port->tx_icr = GxICR_LEVEL_1;
tmp = *port->tx_icr;
/* the transmitter may be disabled */
scxctr = *port->_control;
if (!(scxctr & SC01CTR_TXE)) {
/* restart the UART clock */
tmxmd = *port->_tmxmd;
switch (port->div_timer) {
case MNSCx_DIV_TIMER_16BIT:
*port->_tmxmd = 0;
*port->_tmxmd = TM8MD_INIT_COUNTER;
*port->_tmxmd = tmxmd | TM8MD_COUNT_ENABLE;
break;
case MNSCx_DIV_TIMER_8BIT:
*port->_tmxmd = 0;
*port->_tmxmd = TM2MD_INIT_COUNTER;
*port->_tmxmd = tmxmd | TM2MD_COUNT_ENABLE;
break;
}
/* enable the transmitter */
*port->_control = (scxctr & ~SC01CTR_BKE) | SC01CTR_TXE;
} else if (scxctr & SC01CTR_BKE) {
/* stop transmitting BREAK */
*port->_control = (scxctr & ~SC01CTR_BKE);
}
/* send the chars into the serial port (with LF -> LFCR conversion) */
for (i = 0; i < count; i++) {
char ch = *s++;
while (*port->_status & SC01STR_TBF)
continue;
*(u8 *) port->_txb = ch;
if (ch == 0x0a) {
while (*port->_status & SC01STR_TBF)
continue;
*(u8 *) port->_txb = 0xd;
}
}
/* can't let the transmitter be turned off if it's actually
* transmitting */
while (*port->_status & (SC01STR_TXF | SC01STR_TBF))
continue;
/* disable the transmitter if we re-enabled it */
if (!(scxctr & SC01CTR_TXE))
*port->_control = scxctr;
*port->tx_icr = txicr;
tmp = *port->tx_icr;
}
/*
* set up a serial port as a console
* - construct a cflag setting for the first rs_open()
* - initialize the serial port
* - return non-zero if we didn't find a serial port.
*/
static int __init mn10300_serial_console_setup(struct console *co,
char *options)
{
struct mn10300_serial_port *port;
int i, parity = 'n', baud = 9600, bits = 8, flow = 0;
for (i = 0 ; i < NR_PORTS ; i++) {
port = mn10300_serial_ports[i];
if (port && !port->gdbstub && port->uart.line == co->index)
goto found_device;
}
return -ENODEV;
found_device:
switch (port->clock_src) {
case MNSCx_CLOCK_SRC_IOCLK:
port->ioclk = MN10300_IOCLK;
break;
#ifdef MN10300_IOBCLK
case MNSCx_CLOCK_SRC_IOBCLK:
port->ioclk = MN10300_IOBCLK;
break;
#endif
default:
BUG();
}
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(&port->uart, co, baud, parity, bits, flow);
}
/*
* register console
*/
static int __init mn10300_serial_console_init(void)
{
register_console(&mn10300_serial_console);
return 0;
}
console_initcall(mn10300_serial_console_init);
#endif
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