linux/drivers/tty/serial/sb1250-duart.c
Peter Hurley ef8b9ddcb4 serial: Fix IGNBRK handling
If IGNBRK is set without either BRKINT or PARMRK set, some uart
drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the
line discipline, when it should send either nothing or the TTYBREAK flag
set. This happens because the read_status_mask masks out the BI
condition, which uart_insert_char() then interprets as a normal 0x00 byte.

SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General
Terminal Interface - Input Modes, states:
  "If IGNBRK is set, a break condition detected on input shall be ignored;
   that is, not put on the input queue and therefore not read by any
   process."

Fix read_status_mask to include the BI bit if IGNBRK is set; the
lsr status retains the BI bit if a BREAK is recv'd, which is
subsequently ignored in uart_insert_char() when masked with the
ignore_status_mask.

Affected drivers:
8250 - all
serial_txx9
mfd
amba-pl010
amba-pl011
atmel_serial
bfin_uart
dz
ip22zilog
max310x
mxs-auart
netx-serial
pnx8xxx_uart
pxa
sb1250-duart
sccnxp
serial_ks8695
sirfsoc_uart
st-asc
vr41xx_siu
zs
sunzilog
fsl_lpuart
sunsab
ucc_uart
bcm63xx_uart
sunsu
efm32-uart
pmac_zilog
mpsc
msm_serial
m32r_sio

Unaffected drivers:
omap-serial
rp2
sa1100
imx
icom

Annotated for fixes:
altera_uart
mcf

Drivers without break detection:
21285
xilinx-uartps
altera_jtaguart
apbuart
arc-uart
clps711x
max3100
uartlite
msm_serial_hs
nwpserial
lantiq
vt8500_serial

Unknown:
samsung
mpc52xx_uart
bfin_sport_uart
cpm_uart/core

Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag'
Reported-by: Ivan <athlon_@mail.ru>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-19 13:04:52 -07:00

977 lines
24 KiB
C

/*
* Support for the asynchronous serial interface (DUART) included
* in the BCM1250 and derived System-On-a-Chip (SOC) devices.
*
* Copyright (c) 2007 Maciej W. Rozycki
*
* Derived from drivers/char/sb1250_duart.c for which the following
* copyright applies:
*
* Copyright (c) 2000, 2001, 2002, 2003, 2004 Broadcom Corporation
*
* 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.
*
* References:
*
* "BCM1250/BCM1125/BCM1125H User Manual", Broadcom Corporation
*/
#if defined(CONFIG_SERIAL_SB1250_DUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/compiler.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/major.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/spinlock.h>
#include <linux/sysrq.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/types.h>
#include <linux/atomic.h>
#include <asm/io.h>
#include <asm/war.h>
#include <asm/sibyte/sb1250.h>
#include <asm/sibyte/sb1250_uart.h>
#include <asm/sibyte/swarm.h>
#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/bcm1480_int.h>
#define SBD_CHANREGS(line) A_BCM1480_DUART_CHANREG((line), 0)
#define SBD_CTRLREGS(line) A_BCM1480_DUART_CTRLREG((line), 0)
#define SBD_INT(line) (K_BCM1480_INT_UART_0 + (line))
#define DUART_CHANREG_SPACING BCM1480_DUART_CHANREG_SPACING
#define R_DUART_IMRREG(line) R_BCM1480_DUART_IMRREG(line)
#define R_DUART_INCHREG(line) R_BCM1480_DUART_INCHREG(line)
#define R_DUART_ISRREG(line) R_BCM1480_DUART_ISRREG(line)
#elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/sb1250_int.h>
#define SBD_CHANREGS(line) A_DUART_CHANREG((line), 0)
#define SBD_CTRLREGS(line) A_DUART_CTRLREG(0)
#define SBD_INT(line) (K_INT_UART_0 + (line))
#else
#error invalid SB1250 UART configuration
#endif
MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
MODULE_DESCRIPTION("BCM1xxx on-chip DUART serial driver");
MODULE_LICENSE("GPL");
#define DUART_MAX_CHIP 2
#define DUART_MAX_SIDE 2
/*
* Per-port state.
*/
struct sbd_port {
struct sbd_duart *duart;
struct uart_port port;
unsigned char __iomem *memctrl;
int tx_stopped;
int initialised;
};
/*
* Per-DUART state for the shared register space.
*/
struct sbd_duart {
struct sbd_port sport[2];
unsigned long mapctrl;
atomic_t map_guard;
};
#define to_sport(uport) container_of(uport, struct sbd_port, port)
static struct sbd_duart sbd_duarts[DUART_MAX_CHIP];
/*
* Reading and writing SB1250 DUART registers.
*
* There are three register spaces: two per-channel ones and
* a shared one. We have to define accessors appropriately.
* All registers are 64-bit and all but the Baud Rate Clock
* registers only define 8 least significant bits. There is
* also a workaround to take into account. Raw accessors use
* the full register width, but cooked ones truncate it
* intentionally so that the rest of the driver does not care.
*/
static u64 __read_sbdchn(struct sbd_port *sport, int reg)
{
void __iomem *csr = sport->port.membase + reg;
return __raw_readq(csr);
}
static u64 __read_sbdshr(struct sbd_port *sport, int reg)
{
void __iomem *csr = sport->memctrl + reg;
return __raw_readq(csr);
}
static void __write_sbdchn(struct sbd_port *sport, int reg, u64 value)
{
void __iomem *csr = sport->port.membase + reg;
__raw_writeq(value, csr);
}
static void __write_sbdshr(struct sbd_port *sport, int reg, u64 value)
{
void __iomem *csr = sport->memctrl + reg;
__raw_writeq(value, csr);
}
/*
* In bug 1956, we get glitches that can mess up uart registers. This
* "read-mode-reg after any register access" is an accepted workaround.
*/
static void __war_sbd1956(struct sbd_port *sport)
{
__read_sbdchn(sport, R_DUART_MODE_REG_1);
__read_sbdchn(sport, R_DUART_MODE_REG_2);
}
static unsigned char read_sbdchn(struct sbd_port *sport, int reg)
{
unsigned char retval;
retval = __read_sbdchn(sport, reg);
if (SIBYTE_1956_WAR)
__war_sbd1956(sport);
return retval;
}
static unsigned char read_sbdshr(struct sbd_port *sport, int reg)
{
unsigned char retval;
retval = __read_sbdshr(sport, reg);
if (SIBYTE_1956_WAR)
__war_sbd1956(sport);
return retval;
}
static void write_sbdchn(struct sbd_port *sport, int reg, unsigned int value)
{
__write_sbdchn(sport, reg, value);
if (SIBYTE_1956_WAR)
__war_sbd1956(sport);
}
static void write_sbdshr(struct sbd_port *sport, int reg, unsigned int value)
{
__write_sbdshr(sport, reg, value);
if (SIBYTE_1956_WAR)
__war_sbd1956(sport);
}
static int sbd_receive_ready(struct sbd_port *sport)
{
return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_RX_RDY;
}
static int sbd_receive_drain(struct sbd_port *sport)
{
int loops = 10000;
while (sbd_receive_ready(sport) && --loops)
read_sbdchn(sport, R_DUART_RX_HOLD);
return loops;
}
static int __maybe_unused sbd_transmit_ready(struct sbd_port *sport)
{
return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_RDY;
}
static int __maybe_unused sbd_transmit_drain(struct sbd_port *sport)
{
int loops = 10000;
while (!sbd_transmit_ready(sport) && --loops)
udelay(2);
return loops;
}
static int sbd_transmit_empty(struct sbd_port *sport)
{
return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_EMT;
}
static int sbd_line_drain(struct sbd_port *sport)
{
int loops = 10000;
while (!sbd_transmit_empty(sport) && --loops)
udelay(2);
return loops;
}
static unsigned int sbd_tx_empty(struct uart_port *uport)
{
struct sbd_port *sport = to_sport(uport);
return sbd_transmit_empty(sport) ? TIOCSER_TEMT : 0;
}
static unsigned int sbd_get_mctrl(struct uart_port *uport)
{
struct sbd_port *sport = to_sport(uport);
unsigned int mctrl, status;
status = read_sbdshr(sport, R_DUART_IN_PORT);
status >>= (uport->line) % 2;
mctrl = (!(status & M_DUART_IN_PIN0_VAL) ? TIOCM_CTS : 0) |
(!(status & M_DUART_IN_PIN4_VAL) ? TIOCM_CAR : 0) |
(!(status & M_DUART_RIN0_PIN) ? TIOCM_RNG : 0) |
(!(status & M_DUART_IN_PIN2_VAL) ? TIOCM_DSR : 0);
return mctrl;
}
static void sbd_set_mctrl(struct uart_port *uport, unsigned int mctrl)
{
struct sbd_port *sport = to_sport(uport);
unsigned int clr = 0, set = 0, mode2;
if (mctrl & TIOCM_DTR)
set |= M_DUART_SET_OPR2;
else
clr |= M_DUART_CLR_OPR2;
if (mctrl & TIOCM_RTS)
set |= M_DUART_SET_OPR0;
else
clr |= M_DUART_CLR_OPR0;
clr <<= (uport->line) % 2;
set <<= (uport->line) % 2;
mode2 = read_sbdchn(sport, R_DUART_MODE_REG_2);
mode2 &= ~M_DUART_CHAN_MODE;
if (mctrl & TIOCM_LOOP)
mode2 |= V_DUART_CHAN_MODE_LCL_LOOP;
else
mode2 |= V_DUART_CHAN_MODE_NORMAL;
write_sbdshr(sport, R_DUART_CLEAR_OPR, clr);
write_sbdshr(sport, R_DUART_SET_OPR, set);
write_sbdchn(sport, R_DUART_MODE_REG_2, mode2);
}
static void sbd_stop_tx(struct uart_port *uport)
{
struct sbd_port *sport = to_sport(uport);
write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
sport->tx_stopped = 1;
};
static void sbd_start_tx(struct uart_port *uport)
{
struct sbd_port *sport = to_sport(uport);
unsigned int mask;
/* Enable tx interrupts. */
mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
mask |= M_DUART_IMR_TX;
write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
/* Go!, go!, go!... */
write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
sport->tx_stopped = 0;
};
static void sbd_stop_rx(struct uart_port *uport)
{
struct sbd_port *sport = to_sport(uport);
write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);
};
static void sbd_enable_ms(struct uart_port *uport)
{
struct sbd_port *sport = to_sport(uport);
write_sbdchn(sport, R_DUART_AUXCTL_X,
M_DUART_CIN_CHNG_ENA | M_DUART_CTS_CHNG_ENA);
}
static void sbd_break_ctl(struct uart_port *uport, int break_state)
{
struct sbd_port *sport = to_sport(uport);
if (break_state == -1)
write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_START_BREAK);
else
write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_STOP_BREAK);
}
static void sbd_receive_chars(struct sbd_port *sport)
{
struct uart_port *uport = &sport->port;
struct uart_icount *icount;
unsigned int status, ch, flag;
int count;
for (count = 16; count; count--) {
status = read_sbdchn(sport, R_DUART_STATUS);
if (!(status & M_DUART_RX_RDY))
break;
ch = read_sbdchn(sport, R_DUART_RX_HOLD);
flag = TTY_NORMAL;
icount = &uport->icount;
icount->rx++;
if (unlikely(status &
(M_DUART_RCVD_BRK | M_DUART_FRM_ERR |
M_DUART_PARITY_ERR | M_DUART_OVRUN_ERR))) {
if (status & M_DUART_RCVD_BRK) {
icount->brk++;
if (uart_handle_break(uport))
continue;
} else if (status & M_DUART_FRM_ERR)
icount->frame++;
else if (status & M_DUART_PARITY_ERR)
icount->parity++;
if (status & M_DUART_OVRUN_ERR)
icount->overrun++;
status &= uport->read_status_mask;
if (status & M_DUART_RCVD_BRK)
flag = TTY_BREAK;
else if (status & M_DUART_FRM_ERR)
flag = TTY_FRAME;
else if (status & M_DUART_PARITY_ERR)
flag = TTY_PARITY;
}
if (uart_handle_sysrq_char(uport, ch))
continue;
uart_insert_char(uport, status, M_DUART_OVRUN_ERR, ch, flag);
}
tty_flip_buffer_push(&uport->state->port);
}
static void sbd_transmit_chars(struct sbd_port *sport)
{
struct uart_port *uport = &sport->port;
struct circ_buf *xmit = &sport->port.state->xmit;
unsigned int mask;
int stop_tx;
/* XON/XOFF chars. */
if (sport->port.x_char) {
write_sbdchn(sport, R_DUART_TX_HOLD, sport->port.x_char);
sport->port.icount.tx++;
sport->port.x_char = 0;
return;
}
/* If nothing to do or stopped or hardware stopped. */
stop_tx = (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port));
/* Send char. */
if (!stop_tx) {
write_sbdchn(sport, R_DUART_TX_HOLD, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx++;
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
}
/* Are we are done? */
if (stop_tx || uart_circ_empty(xmit)) {
/* Disable tx interrupts. */
mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
mask &= ~M_DUART_IMR_TX;
write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
}
}
static void sbd_status_handle(struct sbd_port *sport)
{
struct uart_port *uport = &sport->port;
unsigned int delta;
delta = read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
delta >>= (uport->line) % 2;
if (delta & (M_DUART_IN_PIN0_VAL << S_DUART_IN_PIN_CHNG))
uart_handle_cts_change(uport, !(delta & M_DUART_IN_PIN0_VAL));
if (delta & (M_DUART_IN_PIN2_VAL << S_DUART_IN_PIN_CHNG))
uport->icount.dsr++;
if (delta & ((M_DUART_IN_PIN2_VAL | M_DUART_IN_PIN0_VAL) <<
S_DUART_IN_PIN_CHNG))
wake_up_interruptible(&uport->state->port.delta_msr_wait);
}
static irqreturn_t sbd_interrupt(int irq, void *dev_id)
{
struct sbd_port *sport = dev_id;
struct uart_port *uport = &sport->port;
irqreturn_t status = IRQ_NONE;
unsigned int intstat;
int count;
for (count = 16; count; count--) {
intstat = read_sbdshr(sport,
R_DUART_ISRREG((uport->line) % 2));
intstat &= read_sbdshr(sport,
R_DUART_IMRREG((uport->line) % 2));
intstat &= M_DUART_ISR_ALL;
if (!intstat)
break;
if (intstat & M_DUART_ISR_RX)
sbd_receive_chars(sport);
if (intstat & M_DUART_ISR_IN)
sbd_status_handle(sport);
if (intstat & M_DUART_ISR_TX)
sbd_transmit_chars(sport);
status = IRQ_HANDLED;
}
return status;
}
static int sbd_startup(struct uart_port *uport)
{
struct sbd_port *sport = to_sport(uport);
unsigned int mode1;
int ret;
ret = request_irq(sport->port.irq, sbd_interrupt,
IRQF_SHARED, "sb1250-duart", sport);
if (ret)
return ret;
/* Clear the receive FIFO. */
sbd_receive_drain(sport);
/* Clear the interrupt registers. */
write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT);
read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
/* Set rx/tx interrupt to FIFO available. */
mode1 = read_sbdchn(sport, R_DUART_MODE_REG_1);
mode1 &= ~(M_DUART_RX_IRQ_SEL_RXFULL | M_DUART_TX_IRQ_SEL_TXEMPT);
write_sbdchn(sport, R_DUART_MODE_REG_1, mode1);
/* Disable tx, enable rx. */
write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_EN);
sport->tx_stopped = 1;
/* Enable interrupts. */
write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
M_DUART_IMR_IN | M_DUART_IMR_RX);
return 0;
}
static void sbd_shutdown(struct uart_port *uport)
{
struct sbd_port *sport = to_sport(uport);
write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);
sport->tx_stopped = 1;
free_irq(sport->port.irq, sport);
}
static void sbd_init_port(struct sbd_port *sport)
{
struct uart_port *uport = &sport->port;
if (sport->initialised)
return;
/* There is no DUART reset feature, so just set some sane defaults. */
write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_TX);
write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_RX);
write_sbdchn(sport, R_DUART_MODE_REG_1, V_DUART_BITS_PER_CHAR_8);
write_sbdchn(sport, R_DUART_MODE_REG_2, 0);
write_sbdchn(sport, R_DUART_FULL_CTL,
V_DUART_INT_TIME(0) | V_DUART_SIG_FULL(15));
write_sbdchn(sport, R_DUART_OPCR_X, 0);
write_sbdchn(sport, R_DUART_AUXCTL_X, 0);
write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);
sport->initialised = 1;
}
static void sbd_set_termios(struct uart_port *uport, struct ktermios *termios,
struct ktermios *old_termios)
{
struct sbd_port *sport = to_sport(uport);
unsigned int mode1 = 0, mode2 = 0, aux = 0;
unsigned int mode1mask = 0, mode2mask = 0, auxmask = 0;
unsigned int oldmode1, oldmode2, oldaux;
unsigned int baud, brg;
unsigned int command;
mode1mask |= ~(M_DUART_PARITY_MODE | M_DUART_PARITY_TYPE_ODD |
M_DUART_BITS_PER_CHAR);
mode2mask |= ~M_DUART_STOP_BIT_LEN_2;
auxmask |= ~M_DUART_CTS_CHNG_ENA;
/* Byte size. */
switch (termios->c_cflag & CSIZE) {
case CS5:
case CS6:
/* Unsupported, leave unchanged. */
mode1mask |= M_DUART_PARITY_MODE;
break;
case CS7:
mode1 |= V_DUART_BITS_PER_CHAR_7;
break;
case CS8:
default:
mode1 |= V_DUART_BITS_PER_CHAR_8;
break;
}
/* Parity and stop bits. */
if (termios->c_cflag & CSTOPB)
mode2 |= M_DUART_STOP_BIT_LEN_2;
else
mode2 |= M_DUART_STOP_BIT_LEN_1;
if (termios->c_cflag & PARENB)
mode1 |= V_DUART_PARITY_MODE_ADD;
else
mode1 |= V_DUART_PARITY_MODE_NONE;
if (termios->c_cflag & PARODD)
mode1 |= M_DUART_PARITY_TYPE_ODD;
else
mode1 |= M_DUART_PARITY_TYPE_EVEN;
baud = uart_get_baud_rate(uport, termios, old_termios, 1200, 5000000);
brg = V_DUART_BAUD_RATE(baud);
/* The actual lower bound is 1221bps, so compensate. */
if (brg > M_DUART_CLK_COUNTER)
brg = M_DUART_CLK_COUNTER;
uart_update_timeout(uport, termios->c_cflag, baud);
uport->read_status_mask = M_DUART_OVRUN_ERR;
if (termios->c_iflag & INPCK)
uport->read_status_mask |= M_DUART_FRM_ERR |
M_DUART_PARITY_ERR;
if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
uport->read_status_mask |= M_DUART_RCVD_BRK;
uport->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
uport->ignore_status_mask |= M_DUART_FRM_ERR |
M_DUART_PARITY_ERR;
if (termios->c_iflag & IGNBRK) {
uport->ignore_status_mask |= M_DUART_RCVD_BRK;
if (termios->c_iflag & IGNPAR)
uport->ignore_status_mask |= M_DUART_OVRUN_ERR;
}
if (termios->c_cflag & CREAD)
command = M_DUART_RX_EN;
else
command = M_DUART_RX_DIS;
if (termios->c_cflag & CRTSCTS)
aux |= M_DUART_CTS_CHNG_ENA;
else
aux &= ~M_DUART_CTS_CHNG_ENA;
spin_lock(&uport->lock);
if (sport->tx_stopped)
command |= M_DUART_TX_DIS;
else
command |= M_DUART_TX_EN;
oldmode1 = read_sbdchn(sport, R_DUART_MODE_REG_1) & mode1mask;
oldmode2 = read_sbdchn(sport, R_DUART_MODE_REG_2) & mode2mask;
oldaux = read_sbdchn(sport, R_DUART_AUXCTL_X) & auxmask;
if (!sport->tx_stopped)
sbd_line_drain(sport);
write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);
write_sbdchn(sport, R_DUART_MODE_REG_1, mode1 | oldmode1);
write_sbdchn(sport, R_DUART_MODE_REG_2, mode2 | oldmode2);
write_sbdchn(sport, R_DUART_CLK_SEL, brg);
write_sbdchn(sport, R_DUART_AUXCTL_X, aux | oldaux);
write_sbdchn(sport, R_DUART_CMD, command);
spin_unlock(&uport->lock);
}
static const char *sbd_type(struct uart_port *uport)
{
return "SB1250 DUART";
}
static void sbd_release_port(struct uart_port *uport)
{
struct sbd_port *sport = to_sport(uport);
struct sbd_duart *duart = sport->duart;
int map_guard;
iounmap(sport->memctrl);
sport->memctrl = NULL;
iounmap(uport->membase);
uport->membase = NULL;
map_guard = atomic_add_return(-1, &duart->map_guard);
if (!map_guard)
release_mem_region(duart->mapctrl, DUART_CHANREG_SPACING);
release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
}
static int sbd_map_port(struct uart_port *uport)
{
const char *err = KERN_ERR "sbd: Cannot map MMIO\n";
struct sbd_port *sport = to_sport(uport);
struct sbd_duart *duart = sport->duart;
if (!uport->membase)
uport->membase = ioremap_nocache(uport->mapbase,
DUART_CHANREG_SPACING);
if (!uport->membase) {
printk(err);
return -ENOMEM;
}
if (!sport->memctrl)
sport->memctrl = ioremap_nocache(duart->mapctrl,
DUART_CHANREG_SPACING);
if (!sport->memctrl) {
printk(err);
iounmap(uport->membase);
uport->membase = NULL;
return -ENOMEM;
}
return 0;
}
static int sbd_request_port(struct uart_port *uport)
{
const char *err = KERN_ERR "sbd: Unable to reserve MMIO resource\n";
struct sbd_duart *duart = to_sport(uport)->duart;
int map_guard;
int ret = 0;
if (!request_mem_region(uport->mapbase, DUART_CHANREG_SPACING,
"sb1250-duart")) {
printk(err);
return -EBUSY;
}
map_guard = atomic_add_return(1, &duart->map_guard);
if (map_guard == 1) {
if (!request_mem_region(duart->mapctrl, DUART_CHANREG_SPACING,
"sb1250-duart")) {
atomic_add(-1, &duart->map_guard);
printk(err);
ret = -EBUSY;
}
}
if (!ret) {
ret = sbd_map_port(uport);
if (ret) {
map_guard = atomic_add_return(-1, &duart->map_guard);
if (!map_guard)
release_mem_region(duart->mapctrl,
DUART_CHANREG_SPACING);
}
}
if (ret) {
release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
return ret;
}
return 0;
}
static void sbd_config_port(struct uart_port *uport, int flags)
{
struct sbd_port *sport = to_sport(uport);
if (flags & UART_CONFIG_TYPE) {
if (sbd_request_port(uport))
return;
uport->type = PORT_SB1250_DUART;
sbd_init_port(sport);
}
}
static int sbd_verify_port(struct uart_port *uport, struct serial_struct *ser)
{
int ret = 0;
if (ser->type != PORT_UNKNOWN && ser->type != PORT_SB1250_DUART)
ret = -EINVAL;
if (ser->irq != uport->irq)
ret = -EINVAL;
if (ser->baud_base != uport->uartclk / 16)
ret = -EINVAL;
return ret;
}
static const struct uart_ops sbd_ops = {
.tx_empty = sbd_tx_empty,
.set_mctrl = sbd_set_mctrl,
.get_mctrl = sbd_get_mctrl,
.stop_tx = sbd_stop_tx,
.start_tx = sbd_start_tx,
.stop_rx = sbd_stop_rx,
.enable_ms = sbd_enable_ms,
.break_ctl = sbd_break_ctl,
.startup = sbd_startup,
.shutdown = sbd_shutdown,
.set_termios = sbd_set_termios,
.type = sbd_type,
.release_port = sbd_release_port,
.request_port = sbd_request_port,
.config_port = sbd_config_port,
.verify_port = sbd_verify_port,
};
/* Initialize SB1250 DUART port structures. */
static void __init sbd_probe_duarts(void)
{
static int probed;
int chip, side;
int max_lines, line;
if (probed)
return;
/* Set the number of available units based on the SOC type. */
switch (soc_type) {
case K_SYS_SOC_TYPE_BCM1x55:
case K_SYS_SOC_TYPE_BCM1x80:
max_lines = 4;
break;
default:
/* Assume at least two serial ports at the normal address. */
max_lines = 2;
break;
}
probed = 1;
for (chip = 0, line = 0; chip < DUART_MAX_CHIP && line < max_lines;
chip++) {
sbd_duarts[chip].mapctrl = SBD_CTRLREGS(line);
for (side = 0; side < DUART_MAX_SIDE && line < max_lines;
side++, line++) {
struct sbd_port *sport = &sbd_duarts[chip].sport[side];
struct uart_port *uport = &sport->port;
sport->duart = &sbd_duarts[chip];
uport->irq = SBD_INT(line);
uport->uartclk = 100000000 / 20 * 16;
uport->fifosize = 16;
uport->iotype = UPIO_MEM;
uport->flags = UPF_BOOT_AUTOCONF;
uport->ops = &sbd_ops;
uport->line = line;
uport->mapbase = SBD_CHANREGS(line);
}
}
}
#ifdef CONFIG_SERIAL_SB1250_DUART_CONSOLE
/*
* Serial console stuff. Very basic, polling driver for doing serial
* console output. The console_lock is held by the caller, so we
* shouldn't be interrupted for more console activity.
*/
static void sbd_console_putchar(struct uart_port *uport, int ch)
{
struct sbd_port *sport = to_sport(uport);
sbd_transmit_drain(sport);
write_sbdchn(sport, R_DUART_TX_HOLD, ch);
}
static void sbd_console_write(struct console *co, const char *s,
unsigned int count)
{
int chip = co->index / DUART_MAX_SIDE;
int side = co->index % DUART_MAX_SIDE;
struct sbd_port *sport = &sbd_duarts[chip].sport[side];
struct uart_port *uport = &sport->port;
unsigned long flags;
unsigned int mask;
/* Disable transmit interrupts and enable the transmitter. */
spin_lock_irqsave(&uport->lock, flags);
mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
mask & ~M_DUART_IMR_TX);
write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
spin_unlock_irqrestore(&uport->lock, flags);
uart_console_write(&sport->port, s, count, sbd_console_putchar);
/* Restore transmit interrupts and the transmitter enable. */
spin_lock_irqsave(&uport->lock, flags);
sbd_line_drain(sport);
if (sport->tx_stopped)
write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
spin_unlock_irqrestore(&uport->lock, flags);
}
static int __init sbd_console_setup(struct console *co, char *options)
{
int chip = co->index / DUART_MAX_SIDE;
int side = co->index % DUART_MAX_SIDE;
struct sbd_port *sport = &sbd_duarts[chip].sport[side];
struct uart_port *uport = &sport->port;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
int ret;
if (!sport->duart)
return -ENXIO;
ret = sbd_map_port(uport);
if (ret)
return ret;
sbd_init_port(sport);
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(uport, co, baud, parity, bits, flow);
}
static struct uart_driver sbd_reg;
static struct console sbd_console = {
.name = "duart",
.write = sbd_console_write,
.device = uart_console_device,
.setup = sbd_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &sbd_reg
};
static int __init sbd_serial_console_init(void)
{
sbd_probe_duarts();
register_console(&sbd_console);
return 0;
}
console_initcall(sbd_serial_console_init);
#define SERIAL_SB1250_DUART_CONSOLE &sbd_console
#else
#define SERIAL_SB1250_DUART_CONSOLE NULL
#endif /* CONFIG_SERIAL_SB1250_DUART_CONSOLE */
static struct uart_driver sbd_reg = {
.owner = THIS_MODULE,
.driver_name = "sb1250_duart",
.dev_name = "duart",
.major = TTY_MAJOR,
.minor = SB1250_DUART_MINOR_BASE,
.nr = DUART_MAX_CHIP * DUART_MAX_SIDE,
.cons = SERIAL_SB1250_DUART_CONSOLE,
};
/* Set up the driver and register it. */
static int __init sbd_init(void)
{
int i, ret;
sbd_probe_duarts();
ret = uart_register_driver(&sbd_reg);
if (ret)
return ret;
for (i = 0; i < DUART_MAX_CHIP * DUART_MAX_SIDE; i++) {
struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
struct uart_port *uport = &sport->port;
if (sport->duart)
uart_add_one_port(&sbd_reg, uport);
}
return 0;
}
/* Unload the driver. Unregister stuff, get ready to go away. */
static void __exit sbd_exit(void)
{
int i;
for (i = DUART_MAX_CHIP * DUART_MAX_SIDE - 1; i >= 0; i--) {
struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
struct uart_port *uport = &sport->port;
if (sport->duart)
uart_remove_one_port(&sbd_reg, uport);
}
uart_unregister_driver(&sbd_reg);
}
module_init(sbd_init);
module_exit(sbd_exit);