alistair23-linux/drivers/serial/bfin_5xx.c
Sonic Zhang 2860b79111 Blackfin Serial Driver: disable dma rx interrupt only rather than all irqs
The UART RX handling code isn't exactly speeding, so don't go disabling
all interrupts when processing the buffer.  Just disable the relevant DMA
interrupt.  This greatly improves latency of the system when utilizing the
UART.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:51:05 -07:00

1458 lines
37 KiB
C

/*
* Blackfin On-Chip Serial Driver
*
* Copyright 2006-2008 Analog Devices Inc.
*
* Enter bugs at http://blackfin.uclinux.org/
*
* Licensed under the GPL-2 or later.
*/
#if defined(CONFIG_SERIAL_BFIN_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_device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
#include <linux/kgdb.h>
#include <asm/irq_regs.h>
#endif
#include <asm/gpio.h>
#include <mach/bfin_serial_5xx.h>
#ifdef CONFIG_SERIAL_BFIN_DMA
#include <linux/dma-mapping.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/cacheflush.h>
#endif
/* UART name and device definitions */
#define BFIN_SERIAL_NAME "ttyBF"
#define BFIN_SERIAL_MAJOR 204
#define BFIN_SERIAL_MINOR 64
static struct bfin_serial_port bfin_serial_ports[BFIN_UART_NR_PORTS];
static int nr_active_ports = ARRAY_SIZE(bfin_serial_resource);
#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
# ifndef CONFIG_SERIAL_BFIN_PIO
# error KGDB only support UART in PIO mode.
# endif
static int kgdboc_port_line;
static int kgdboc_break_enabled;
#endif
/*
* Setup for console. Argument comes from the menuconfig
*/
#define DMA_RX_XCOUNT 512
#define DMA_RX_YCOUNT (PAGE_SIZE / DMA_RX_XCOUNT)
#define DMA_RX_FLUSH_JIFFIES (HZ / 50)
#ifdef CONFIG_SERIAL_BFIN_DMA
static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
#else
static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
#endif
static void bfin_serial_reset_irda(struct uart_port *port);
#if defined(CONFIG_SERIAL_BFIN_CTSRTS) || \
defined(CONFIG_SERIAL_BFIN_HARD_CTSRTS)
static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
if (uart->cts_pin < 0)
return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
/* CTS PIN is negative assertive. */
if (UART_GET_CTS(uart))
return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
else
return TIOCM_DSR | TIOCM_CAR;
}
static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
if (uart->rts_pin < 0)
return;
/* RTS PIN is negative assertive. */
if (mctrl & TIOCM_RTS)
UART_ENABLE_RTS(uart);
else
UART_DISABLE_RTS(uart);
}
/*
* Handle any change of modem status signal.
*/
static irqreturn_t bfin_serial_mctrl_cts_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
unsigned int status;
status = bfin_serial_get_mctrl(&uart->port);
uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
#ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
uart->scts = 1;
UART_CLEAR_SCTS(uart);
UART_CLEAR_IER(uart, EDSSI);
#endif
return IRQ_HANDLED;
}
#else
static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
{
return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
}
static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
}
#endif
/*
* interrupts are disabled on entry
*/
static void bfin_serial_stop_tx(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
#ifdef CONFIG_SERIAL_BFIN_DMA
struct circ_buf *xmit = &uart->port.info->xmit;
#endif
while (!(UART_GET_LSR(uart) & TEMT))
cpu_relax();
#ifdef CONFIG_SERIAL_BFIN_DMA
disable_dma(uart->tx_dma_channel);
xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
uart->port.icount.tx += uart->tx_count;
uart->tx_count = 0;
uart->tx_done = 1;
#else
#ifdef CONFIG_BF54x
/* Clear TFI bit */
UART_PUT_LSR(uart, TFI);
#endif
UART_CLEAR_IER(uart, ETBEI);
#endif
}
/*
* port is locked and interrupts are disabled
*/
static void bfin_serial_start_tx(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
struct tty_struct *tty = uart->port.info->port.tty;
#ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
if (uart->scts && !(bfin_serial_get_mctrl(&uart->port) & TIOCM_CTS)) {
uart->scts = 0;
uart_handle_cts_change(&uart->port, uart->scts);
}
#endif
/*
* To avoid losting RX interrupt, we reset IR function
* before sending data.
*/
if (tty->termios->c_line == N_IRDA)
bfin_serial_reset_irda(port);
#ifdef CONFIG_SERIAL_BFIN_DMA
if (uart->tx_done)
bfin_serial_dma_tx_chars(uart);
#else
UART_SET_IER(uart, ETBEI);
bfin_serial_tx_chars(uart);
#endif
}
/*
* Interrupts are enabled
*/
static void bfin_serial_stop_rx(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
UART_CLEAR_IER(uart, ERBFI);
}
/*
* Set the modem control timer to fire immediately.
*/
static void bfin_serial_enable_ms(struct uart_port *port)
{
}
#if ANOMALY_05000363 && defined(CONFIG_SERIAL_BFIN_PIO)
# define UART_GET_ANOMALY_THRESHOLD(uart) ((uart)->anomaly_threshold)
# define UART_SET_ANOMALY_THRESHOLD(uart, v) ((uart)->anomaly_threshold = (v))
#else
# define UART_GET_ANOMALY_THRESHOLD(uart) 0
# define UART_SET_ANOMALY_THRESHOLD(uart, v)
#endif
#ifdef CONFIG_SERIAL_BFIN_PIO
static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
{
struct tty_struct *tty = NULL;
unsigned int status, ch, flg;
static struct timeval anomaly_start = { .tv_sec = 0 };
status = UART_GET_LSR(uart);
UART_CLEAR_LSR(uart);
ch = UART_GET_CHAR(uart);
uart->port.icount.rx++;
#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
if (kgdb_connected && kgdboc_port_line == uart->port.line)
if (ch == 0x3) {/* Ctrl + C */
kgdb_breakpoint();
return;
}
if (!uart->port.info || !uart->port.info->port.tty)
return;
#endif
tty = uart->port.info->port.tty;
if (ANOMALY_05000363) {
/* The BF533 (and BF561) family of processors have a nice anomaly
* where they continuously generate characters for a "single" break.
* We have to basically ignore this flood until the "next" valid
* character comes across. Due to the nature of the flood, it is
* not possible to reliably catch bytes that are sent too quickly
* after this break. So application code talking to the Blackfin
* which sends a break signal must allow at least 1.5 character
* times after the end of the break for things to stabilize. This
* timeout was picked as it must absolutely be larger than 1
* character time +/- some percent. So 1.5 sounds good. All other
* Blackfin families operate properly. Woo.
*/
if (anomaly_start.tv_sec) {
struct timeval curr;
suseconds_t usecs;
if ((~ch & (~ch + 1)) & 0xff)
goto known_good_char;
do_gettimeofday(&curr);
if (curr.tv_sec - anomaly_start.tv_sec > 1)
goto known_good_char;
usecs = 0;
if (curr.tv_sec != anomaly_start.tv_sec)
usecs += USEC_PER_SEC;
usecs += curr.tv_usec - anomaly_start.tv_usec;
if (usecs > UART_GET_ANOMALY_THRESHOLD(uart))
goto known_good_char;
if (ch)
anomaly_start.tv_sec = 0;
else
anomaly_start = curr;
return;
known_good_char:
status &= ~BI;
anomaly_start.tv_sec = 0;
}
}
if (status & BI) {
if (ANOMALY_05000363)
if (bfin_revid() < 5)
do_gettimeofday(&anomaly_start);
uart->port.icount.brk++;
if (uart_handle_break(&uart->port))
goto ignore_char;
status &= ~(PE | FE);
}
if (status & PE)
uart->port.icount.parity++;
if (status & OE)
uart->port.icount.overrun++;
if (status & FE)
uart->port.icount.frame++;
status &= uart->port.read_status_mask;
if (status & BI)
flg = TTY_BREAK;
else if (status & PE)
flg = TTY_PARITY;
else if (status & FE)
flg = TTY_FRAME;
else
flg = TTY_NORMAL;
if (uart_handle_sysrq_char(&uart->port, ch))
goto ignore_char;
uart_insert_char(&uart->port, status, OE, ch, flg);
ignore_char:
tty_flip_buffer_push(tty);
}
static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
{
struct circ_buf *xmit = &uart->port.info->xmit;
if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
#ifdef CONFIG_BF54x
/* Clear TFI bit */
UART_PUT_LSR(uart, TFI);
#endif
/* Anomaly notes:
* 05000215 - we always clear ETBEI within last UART TX
* interrupt to end a string. It is always set
* when start a new tx.
*/
UART_CLEAR_IER(uart, ETBEI);
return;
}
if (uart->port.x_char) {
UART_PUT_CHAR(uart, uart->port.x_char);
uart->port.icount.tx++;
uart->port.x_char = 0;
}
while ((UART_GET_LSR(uart) & THRE) && xmit->tail != xmit->head) {
UART_PUT_CHAR(uart, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
uart->port.icount.tx++;
SSYNC();
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&uart->port);
}
static irqreturn_t bfin_serial_rx_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
spin_lock(&uart->port.lock);
while (UART_GET_LSR(uart) & DR)
bfin_serial_rx_chars(uart);
spin_unlock(&uart->port.lock);
return IRQ_HANDLED;
}
static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
#ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
if (uart->scts && !(bfin_serial_get_mctrl(&uart->port) & TIOCM_CTS)) {
uart->scts = 0;
uart_handle_cts_change(&uart->port, uart->scts);
}
#endif
spin_lock(&uart->port.lock);
if (UART_GET_LSR(uart) & THRE)
bfin_serial_tx_chars(uart);
spin_unlock(&uart->port.lock);
return IRQ_HANDLED;
}
#endif
#ifdef CONFIG_SERIAL_BFIN_DMA
static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
{
struct circ_buf *xmit = &uart->port.info->xmit;
uart->tx_done = 0;
if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
uart->tx_count = 0;
uart->tx_done = 1;
return;
}
if (uart->port.x_char) {
UART_PUT_CHAR(uart, uart->port.x_char);
uart->port.icount.tx++;
uart->port.x_char = 0;
}
uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))
uart->tx_count = UART_XMIT_SIZE - xmit->tail;
blackfin_dcache_flush_range((unsigned long)(xmit->buf+xmit->tail),
(unsigned long)(xmit->buf+xmit->tail+uart->tx_count));
set_dma_config(uart->tx_dma_channel,
set_bfin_dma_config(DIR_READ, DMA_FLOW_STOP,
INTR_ON_BUF,
DIMENSION_LINEAR,
DATA_SIZE_8,
DMA_SYNC_RESTART));
set_dma_start_addr(uart->tx_dma_channel, (unsigned long)(xmit->buf+xmit->tail));
set_dma_x_count(uart->tx_dma_channel, uart->tx_count);
set_dma_x_modify(uart->tx_dma_channel, 1);
SSYNC();
enable_dma(uart->tx_dma_channel);
UART_SET_IER(uart, ETBEI);
}
static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
{
struct tty_struct *tty = uart->port.info->port.tty;
int i, flg, status;
status = UART_GET_LSR(uart);
UART_CLEAR_LSR(uart);
uart->port.icount.rx +=
CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail,
UART_XMIT_SIZE);
if (status & BI) {
uart->port.icount.brk++;
if (uart_handle_break(&uart->port))
goto dma_ignore_char;
status &= ~(PE | FE);
}
if (status & PE)
uart->port.icount.parity++;
if (status & OE)
uart->port.icount.overrun++;
if (status & FE)
uart->port.icount.frame++;
status &= uart->port.read_status_mask;
if (status & BI)
flg = TTY_BREAK;
else if (status & PE)
flg = TTY_PARITY;
else if (status & FE)
flg = TTY_FRAME;
else
flg = TTY_NORMAL;
for (i = uart->rx_dma_buf.tail; ; i++) {
if (i >= UART_XMIT_SIZE)
i = 0;
if (i == uart->rx_dma_buf.head)
break;
if (!uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
uart_insert_char(&uart->port, status, OE,
uart->rx_dma_buf.buf[i], flg);
}
dma_ignore_char:
tty_flip_buffer_push(tty);
}
void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
{
int x_pos, pos;
dma_disable_irq(uart->rx_dma_channel);
spin_lock_bh(&uart->port.lock);
/* 2D DMA RX buffer ring is used. Because curr_y_count and
* curr_x_count can't be read as an atomic operation,
* curr_y_count should be read before curr_x_count. When
* curr_x_count is read, curr_y_count may already indicate
* next buffer line. But, the position calculated here is
* still indicate the old line. The wrong position data may
* be smaller than current buffer tail, which cause garbages
* are received if it is not prohibit.
*/
uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);
x_pos = get_dma_curr_xcount(uart->rx_dma_channel);
uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;
if (uart->rx_dma_nrows == DMA_RX_YCOUNT || x_pos == 0)
uart->rx_dma_nrows = 0;
x_pos = DMA_RX_XCOUNT - x_pos;
if (x_pos == DMA_RX_XCOUNT)
x_pos = 0;
pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
/* Ignore receiving data if new position is in the same line of
* current buffer tail and small.
*/
if (pos > uart->rx_dma_buf.tail ||
uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) {
uart->rx_dma_buf.head = pos;
bfin_serial_dma_rx_chars(uart);
uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
}
spin_unlock_bh(&uart->port.lock);
dma_enable_irq(uart->rx_dma_channel);
mod_timer(&(uart->rx_dma_timer), jiffies + DMA_RX_FLUSH_JIFFIES);
}
static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
struct circ_buf *xmit = &uart->port.info->xmit;
#ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
if (uart->scts && !(bfin_serial_get_mctrl(&uart->port)&TIOCM_CTS)) {
uart->scts = 0;
uart_handle_cts_change(&uart->port, uart->scts);
}
#endif
spin_lock(&uart->port.lock);
if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
disable_dma(uart->tx_dma_channel);
clear_dma_irqstat(uart->tx_dma_channel);
/* Anomaly notes:
* 05000215 - we always clear ETBEI within last UART TX
* interrupt to end a string. It is always set
* when start a new tx.
*/
UART_CLEAR_IER(uart, ETBEI);
xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
uart->port.icount.tx += uart->tx_count;
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&uart->port);
bfin_serial_dma_tx_chars(uart);
}
spin_unlock(&uart->port.lock);
return IRQ_HANDLED;
}
static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
unsigned short irqstat;
int x_pos, pos;
spin_lock(&uart->port.lock);
irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
clear_dma_irqstat(uart->rx_dma_channel);
uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);
x_pos = get_dma_curr_xcount(uart->rx_dma_channel);
uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;
if (uart->rx_dma_nrows == DMA_RX_YCOUNT || x_pos == 0)
uart->rx_dma_nrows = 0;
pos = uart->rx_dma_nrows * DMA_RX_XCOUNT;
if (pos > uart->rx_dma_buf.tail ||
uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) {
uart->rx_dma_buf.head = pos;
bfin_serial_dma_rx_chars(uart);
uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
}
spin_unlock(&uart->port.lock);
return IRQ_HANDLED;
}
#endif
/*
* Return TIOCSER_TEMT when transmitter is not busy.
*/
static unsigned int bfin_serial_tx_empty(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
unsigned short lsr;
lsr = UART_GET_LSR(uart);
if (lsr & TEMT)
return TIOCSER_TEMT;
else
return 0;
}
static void bfin_serial_break_ctl(struct uart_port *port, int break_state)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
u16 lcr = UART_GET_LCR(uart);
if (break_state)
lcr |= SB;
else
lcr &= ~SB;
UART_PUT_LCR(uart, lcr);
SSYNC();
}
static int bfin_serial_startup(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
#ifdef CONFIG_SERIAL_BFIN_DMA
dma_addr_t dma_handle;
if (request_dma(uart->rx_dma_channel, "BFIN_UART_RX") < 0) {
printk(KERN_NOTICE "Unable to attach Blackfin UART RX DMA channel\n");
return -EBUSY;
}
if (request_dma(uart->tx_dma_channel, "BFIN_UART_TX") < 0) {
printk(KERN_NOTICE "Unable to attach Blackfin UART TX DMA channel\n");
free_dma(uart->rx_dma_channel);
return -EBUSY;
}
set_dma_callback(uart->rx_dma_channel, bfin_serial_dma_rx_int, uart);
set_dma_callback(uart->tx_dma_channel, bfin_serial_dma_tx_int, uart);
uart->rx_dma_buf.buf = (unsigned char *)dma_alloc_coherent(NULL, PAGE_SIZE, &dma_handle, GFP_DMA);
uart->rx_dma_buf.head = 0;
uart->rx_dma_buf.tail = 0;
uart->rx_dma_nrows = 0;
set_dma_config(uart->rx_dma_channel,
set_bfin_dma_config(DIR_WRITE, DMA_FLOW_AUTO,
INTR_ON_ROW, DIMENSION_2D,
DATA_SIZE_8,
DMA_SYNC_RESTART));
set_dma_x_count(uart->rx_dma_channel, DMA_RX_XCOUNT);
set_dma_x_modify(uart->rx_dma_channel, 1);
set_dma_y_count(uart->rx_dma_channel, DMA_RX_YCOUNT);
set_dma_y_modify(uart->rx_dma_channel, 1);
set_dma_start_addr(uart->rx_dma_channel, (unsigned long)uart->rx_dma_buf.buf);
enable_dma(uart->rx_dma_channel);
uart->rx_dma_timer.data = (unsigned long)(uart);
uart->rx_dma_timer.function = (void *)bfin_serial_rx_dma_timeout;
uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
add_timer(&(uart->rx_dma_timer));
#else
# if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
if (kgdboc_port_line == uart->port.line && kgdboc_break_enabled)
kgdboc_break_enabled = 0;
else {
# endif
if (request_irq(uart->port.irq, bfin_serial_rx_int, IRQF_DISABLED,
"BFIN_UART_RX", uart)) {
printk(KERN_NOTICE "Unable to attach BlackFin UART RX interrupt\n");
return -EBUSY;
}
if (request_irq
(uart->port.irq+1, bfin_serial_tx_int, IRQF_DISABLED,
"BFIN_UART_TX", uart)) {
printk(KERN_NOTICE "Unable to attach BlackFin UART TX interrupt\n");
free_irq(uart->port.irq, uart);
return -EBUSY;
}
# ifdef CONFIG_BF54x
{
unsigned uart_dma_ch_rx, uart_dma_ch_tx;
switch (uart->port.irq) {
case IRQ_UART3_RX:
uart_dma_ch_rx = CH_UART3_RX;
uart_dma_ch_tx = CH_UART3_TX;
break;
case IRQ_UART2_RX:
uart_dma_ch_rx = CH_UART2_RX;
uart_dma_ch_tx = CH_UART2_TX;
break;
default:
uart_dma_ch_rx = uart_dma_ch_tx = 0;
break;
};
if (uart_dma_ch_rx &&
request_dma(uart_dma_ch_rx, "BFIN_UART_RX") < 0) {
printk(KERN_NOTICE"Fail to attach UART interrupt\n");
free_irq(uart->port.irq, uart);
free_irq(uart->port.irq + 1, uart);
return -EBUSY;
}
if (uart_dma_ch_tx &&
request_dma(uart_dma_ch_tx, "BFIN_UART_TX") < 0) {
printk(KERN_NOTICE "Fail to attach UART interrupt\n");
free_dma(uart_dma_ch_rx);
free_irq(uart->port.irq, uart);
free_irq(uart->port.irq + 1, uart);
return -EBUSY;
}
}
# endif
# if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
}
# endif
#endif
#ifdef CONFIG_SERIAL_BFIN_CTSRTS
if (uart->cts_pin >= 0) {
if (request_irq(gpio_to_irq(uart->cts_pin),
bfin_serial_mctrl_cts_int,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
IRQF_DISABLED, "BFIN_UART_CTS", uart)) {
uart->cts_pin = -1;
pr_info("Unable to attach BlackFin UART CTS interrupt.\
So, disable it.\n");
}
}
if (uart->rts_pin >= 0) {
gpio_request(uart->rts_pin, DRIVER_NAME);
gpio_direction_output(uart->rts_pin, 0);
}
#endif
#ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
if (request_irq(uart->status_irq,
bfin_serial_mctrl_cts_int,
IRQF_DISABLED, "BFIN_UART_MODEM_STATUS", uart)) {
pr_info("Unable to attach BlackFin UART Modem \
Status interrupt.\n");
}
if (uart->cts_pin >= 0) {
gpio_request(uart->cts_pin, DRIVER_NAME);
gpio_direction_output(uart->cts_pin, 1);
}
if (uart->rts_pin >= 0) {
gpio_request(uart->rts_pin, DRIVER_NAME);
gpio_direction_output(uart->rts_pin, 0);
}
/* CTS RTS PINs are negative assertive. */
UART_PUT_MCR(uart, ACTS);
UART_SET_IER(uart, EDSSI);
#endif
UART_SET_IER(uart, ERBFI);
return 0;
}
static void bfin_serial_shutdown(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
#ifdef CONFIG_SERIAL_BFIN_DMA
disable_dma(uart->tx_dma_channel);
free_dma(uart->tx_dma_channel);
disable_dma(uart->rx_dma_channel);
free_dma(uart->rx_dma_channel);
del_timer(&(uart->rx_dma_timer));
dma_free_coherent(NULL, PAGE_SIZE, uart->rx_dma_buf.buf, 0);
#else
#ifdef CONFIG_BF54x
switch (uart->port.irq) {
case IRQ_UART3_RX:
free_dma(CH_UART3_RX);
free_dma(CH_UART3_TX);
break;
case IRQ_UART2_RX:
free_dma(CH_UART2_RX);
free_dma(CH_UART2_TX);
break;
default:
break;
};
#endif
free_irq(uart->port.irq, uart);
free_irq(uart->port.irq+1, uart);
#endif
#ifdef CONFIG_SERIAL_BFIN_CTSRTS
if (uart->cts_pin >= 0)
free_irq(gpio_to_irq(uart->cts_pin), uart);
if (uart->rts_pin >= 0)
gpio_free(uart->rts_pin);
#endif
#ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
if (uart->cts_pin >= 0)
gpio_free(uart->cts_pin);
if (uart->rts_pin >= 0)
gpio_free(uart->rts_pin);
if (UART_GET_IER(uart) && EDSSI)
free_irq(uart->status_irq, uart);
#endif
}
static void
bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
unsigned long flags;
unsigned int baud, quot;
unsigned short val, ier, lcr = 0;
switch (termios->c_cflag & CSIZE) {
case CS8:
lcr = WLS(8);
break;
case CS7:
lcr = WLS(7);
break;
case CS6:
lcr = WLS(6);
break;
case CS5:
lcr = WLS(5);
break;
default:
printk(KERN_ERR "%s: word lengh not supported\n",
__func__);
}
/* Anomaly notes:
* 05000231 - STOP bit is always set to 1 whatever the user is set.
*/
if (termios->c_cflag & CSTOPB) {
if (ANOMALY_05000231)
printk(KERN_WARNING "STOP bits other than 1 is not "
"supported in case of anomaly 05000231.\n");
else
lcr |= STB;
}
if (termios->c_cflag & PARENB)
lcr |= PEN;
if (!(termios->c_cflag & PARODD))
lcr |= EPS;
if (termios->c_cflag & CMSPAR)
lcr |= STP;
port->read_status_mask = OE;
if (termios->c_iflag & INPCK)
port->read_status_mask |= (FE | PE);
if (termios->c_iflag & (BRKINT | PARMRK))
port->read_status_mask |= BI;
/*
* Characters to ignore
*/
port->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= FE | PE;
if (termios->c_iflag & IGNBRK) {
port->ignore_status_mask |= BI;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= OE;
}
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
quot = uart_get_divisor(port, baud) - ANOMALY_05000230;
spin_lock_irqsave(&uart->port.lock, flags);
UART_SET_ANOMALY_THRESHOLD(uart, USEC_PER_SEC / baud * 15);
/* Disable UART */
ier = UART_GET_IER(uart);
UART_DISABLE_INTS(uart);
/* Set DLAB in LCR to Access DLL and DLH */
UART_SET_DLAB(uart);
UART_PUT_DLL(uart, quot & 0xFF);
UART_PUT_DLH(uart, (quot >> 8) & 0xFF);
SSYNC();
/* Clear DLAB in LCR to Access THR RBR IER */
UART_CLEAR_DLAB(uart);
UART_PUT_LCR(uart, lcr);
/* Enable UART */
UART_ENABLE_INTS(uart, ier);
val = UART_GET_GCTL(uart);
val |= UCEN;
UART_PUT_GCTL(uart, val);
/* Port speed changed, update the per-port timeout. */
uart_update_timeout(port, termios->c_cflag, baud);
spin_unlock_irqrestore(&uart->port.lock, flags);
}
static const char *bfin_serial_type(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
return uart->port.type == PORT_BFIN ? "BFIN-UART" : NULL;
}
/*
* Release the memory region(s) being used by 'port'.
*/
static void bfin_serial_release_port(struct uart_port *port)
{
}
/*
* Request the memory region(s) being used by 'port'.
*/
static int bfin_serial_request_port(struct uart_port *port)
{
return 0;
}
/*
* Configure/autoconfigure the port.
*/
static void bfin_serial_config_port(struct uart_port *port, int flags)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
if (flags & UART_CONFIG_TYPE &&
bfin_serial_request_port(&uart->port) == 0)
uart->port.type = PORT_BFIN;
}
/*
* Verify the new serial_struct (for TIOCSSERIAL).
* The only change we allow are to the flags and type, and
* even then only between PORT_BFIN and PORT_UNKNOWN
*/
static int
bfin_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
{
return 0;
}
/*
* Enable the IrDA function if tty->ldisc.num is N_IRDA.
* In other cases, disable IrDA function.
*/
static void bfin_serial_set_ldisc(struct uart_port *port)
{
int line = port->line;
unsigned short val;
if (line >= port->info->port.tty->driver->num)
return;
switch (port->info->port.tty->termios->c_line) {
case N_IRDA:
val = UART_GET_GCTL(&bfin_serial_ports[line]);
val |= (IREN | RPOLC);
UART_PUT_GCTL(&bfin_serial_ports[line], val);
break;
default:
val = UART_GET_GCTL(&bfin_serial_ports[line]);
val &= ~(IREN | RPOLC);
UART_PUT_GCTL(&bfin_serial_ports[line], val);
}
}
static void bfin_serial_reset_irda(struct uart_port *port)
{
int line = port->line;
unsigned short val;
val = UART_GET_GCTL(&bfin_serial_ports[line]);
val &= ~(IREN | RPOLC);
UART_PUT_GCTL(&bfin_serial_ports[line], val);
SSYNC();
val |= (IREN | RPOLC);
UART_PUT_GCTL(&bfin_serial_ports[line], val);
SSYNC();
}
#ifdef CONFIG_CONSOLE_POLL
/* Anomaly notes:
* 05000099 - Because we only use THRE in poll_put and DR in poll_get,
* losing other bits of UART_LSR is not a problem here.
*/
static void bfin_serial_poll_put_char(struct uart_port *port, unsigned char chr)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
while (!(UART_GET_LSR(uart) & THRE))
cpu_relax();
UART_CLEAR_DLAB(uart);
UART_PUT_CHAR(uart, (unsigned char)chr);
}
static int bfin_serial_poll_get_char(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
unsigned char chr;
while (!(UART_GET_LSR(uart) & DR))
cpu_relax();
UART_CLEAR_DLAB(uart);
chr = UART_GET_CHAR(uart);
return chr;
}
#endif
#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
static void bfin_kgdboc_port_shutdown(struct uart_port *port)
{
if (kgdboc_break_enabled) {
kgdboc_break_enabled = 0;
bfin_serial_shutdown(port);
}
}
static int bfin_kgdboc_port_startup(struct uart_port *port)
{
kgdboc_port_line = port->line;
kgdboc_break_enabled = !bfin_serial_startup(port);
return 0;
}
#endif
static struct uart_ops bfin_serial_pops = {
.tx_empty = bfin_serial_tx_empty,
.set_mctrl = bfin_serial_set_mctrl,
.get_mctrl = bfin_serial_get_mctrl,
.stop_tx = bfin_serial_stop_tx,
.start_tx = bfin_serial_start_tx,
.stop_rx = bfin_serial_stop_rx,
.enable_ms = bfin_serial_enable_ms,
.break_ctl = bfin_serial_break_ctl,
.startup = bfin_serial_startup,
.shutdown = bfin_serial_shutdown,
.set_termios = bfin_serial_set_termios,
.set_ldisc = bfin_serial_set_ldisc,
.type = bfin_serial_type,
.release_port = bfin_serial_release_port,
.request_port = bfin_serial_request_port,
.config_port = bfin_serial_config_port,
.verify_port = bfin_serial_verify_port,
#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
.kgdboc_port_startup = bfin_kgdboc_port_startup,
.kgdboc_port_shutdown = bfin_kgdboc_port_shutdown,
#endif
#ifdef CONFIG_CONSOLE_POLL
.poll_put_char = bfin_serial_poll_put_char,
.poll_get_char = bfin_serial_poll_get_char,
#endif
};
static void __init bfin_serial_hw_init(void)
{
#ifdef CONFIG_SERIAL_BFIN_UART0
peripheral_request(P_UART0_TX, DRIVER_NAME);
peripheral_request(P_UART0_RX, DRIVER_NAME);
#endif
#ifdef CONFIG_SERIAL_BFIN_UART1
peripheral_request(P_UART1_TX, DRIVER_NAME);
peripheral_request(P_UART1_RX, DRIVER_NAME);
# if defined(CONFIG_BFIN_UART1_CTSRTS) && defined(CONFIG_BF54x)
peripheral_request(P_UART1_RTS, DRIVER_NAME);
peripheral_request(P_UART1_CTS, DRIVER_NAME);
# endif
#endif
#ifdef CONFIG_SERIAL_BFIN_UART2
peripheral_request(P_UART2_TX, DRIVER_NAME);
peripheral_request(P_UART2_RX, DRIVER_NAME);
#endif
#ifdef CONFIG_SERIAL_BFIN_UART3
peripheral_request(P_UART3_TX, DRIVER_NAME);
peripheral_request(P_UART3_RX, DRIVER_NAME);
# if defined(CONFIG_BFIN_UART3_CTSRTS) && defined(CONFIG_BF54x)
peripheral_request(P_UART3_RTS, DRIVER_NAME);
peripheral_request(P_UART3_CTS, DRIVER_NAME);
# endif
#endif
}
static void __init bfin_serial_init_ports(void)
{
static int first = 1;
int i;
if (!first)
return;
first = 0;
bfin_serial_hw_init();
for (i = 0; i < nr_active_ports; i++) {
bfin_serial_ports[i].port.uartclk = get_sclk();
bfin_serial_ports[i].port.fifosize = BFIN_UART_TX_FIFO_SIZE;
bfin_serial_ports[i].port.ops = &bfin_serial_pops;
bfin_serial_ports[i].port.line = i;
bfin_serial_ports[i].port.iotype = UPIO_MEM;
bfin_serial_ports[i].port.membase =
(void __iomem *)bfin_serial_resource[i].uart_base_addr;
bfin_serial_ports[i].port.mapbase =
bfin_serial_resource[i].uart_base_addr;
bfin_serial_ports[i].port.irq =
bfin_serial_resource[i].uart_irq;
bfin_serial_ports[i].status_irq =
bfin_serial_resource[i].uart_status_irq;
bfin_serial_ports[i].port.flags = UPF_BOOT_AUTOCONF;
#ifdef CONFIG_SERIAL_BFIN_DMA
bfin_serial_ports[i].tx_done = 1;
bfin_serial_ports[i].tx_count = 0;
bfin_serial_ports[i].tx_dma_channel =
bfin_serial_resource[i].uart_tx_dma_channel;
bfin_serial_ports[i].rx_dma_channel =
bfin_serial_resource[i].uart_rx_dma_channel;
init_timer(&(bfin_serial_ports[i].rx_dma_timer));
#endif
#if defined(CONFIG_SERIAL_BFIN_CTSRTS) || \
defined(CONFIG_SERIAL_BFIN_HARD_CTSRTS)
bfin_serial_ports[i].cts_pin =
bfin_serial_resource[i].uart_cts_pin;
bfin_serial_ports[i].rts_pin =
bfin_serial_resource[i].uart_rts_pin;
#endif
}
}
#if defined(CONFIG_SERIAL_BFIN_CONSOLE) || defined(CONFIG_EARLY_PRINTK)
/*
* If the port was already initialised (eg, by a boot loader),
* try to determine the current setup.
*/
static void __init
bfin_serial_console_get_options(struct bfin_serial_port *uart, int *baud,
int *parity, int *bits)
{
unsigned short status;
status = UART_GET_IER(uart) & (ERBFI | ETBEI);
if (status == (ERBFI | ETBEI)) {
/* ok, the port was enabled */
u16 lcr, dlh, dll;
lcr = UART_GET_LCR(uart);
*parity = 'n';
if (lcr & PEN) {
if (lcr & EPS)
*parity = 'e';
else
*parity = 'o';
}
switch (lcr & 0x03) {
case 0: *bits = 5; break;
case 1: *bits = 6; break;
case 2: *bits = 7; break;
case 3: *bits = 8; break;
}
/* Set DLAB in LCR to Access DLL and DLH */
UART_SET_DLAB(uart);
dll = UART_GET_DLL(uart);
dlh = UART_GET_DLH(uart);
/* Clear DLAB in LCR to Access THR RBR IER */
UART_CLEAR_DLAB(uart);
*baud = get_sclk() / (16*(dll | dlh << 8));
}
pr_debug("%s:baud = %d, parity = %c, bits= %d\n", __func__, *baud, *parity, *bits);
}
static struct uart_driver bfin_serial_reg;
static int __init
bfin_serial_console_setup(struct console *co, char *options)
{
struct bfin_serial_port *uart;
int baud = 57600;
int bits = 8;
int parity = 'n';
# if defined(CONFIG_SERIAL_BFIN_CTSRTS) || \
defined(CONFIG_SERIAL_BFIN_HARD_CTSRTS)
int flow = 'r';
# else
int flow = 'n';
# endif
/*
* 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_active_ports)
co->index = 0;
uart = &bfin_serial_ports[co->index];
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
bfin_serial_console_get_options(uart, &baud, &parity, &bits);
return uart_set_options(&uart->port, co, baud, parity, bits, flow);
}
#endif /* defined (CONFIG_SERIAL_BFIN_CONSOLE) ||
defined (CONFIG_EARLY_PRINTK) */
#ifdef CONFIG_SERIAL_BFIN_CONSOLE
static void bfin_serial_console_putchar(struct uart_port *port, int ch)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
while (!(UART_GET_LSR(uart) & THRE))
barrier();
UART_PUT_CHAR(uart, ch);
SSYNC();
}
/*
* Interrupts are disabled on entering
*/
static void
bfin_serial_console_write(struct console *co, const char *s, unsigned int count)
{
struct bfin_serial_port *uart = &bfin_serial_ports[co->index];
unsigned long flags;
spin_lock_irqsave(&uart->port.lock, flags);
uart_console_write(&uart->port, s, count, bfin_serial_console_putchar);
spin_unlock_irqrestore(&uart->port.lock, flags);
}
static struct console bfin_serial_console = {
.name = BFIN_SERIAL_NAME,
.write = bfin_serial_console_write,
.device = uart_console_device,
.setup = bfin_serial_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &bfin_serial_reg,
};
static int __init bfin_serial_rs_console_init(void)
{
bfin_serial_init_ports();
register_console(&bfin_serial_console);
return 0;
}
console_initcall(bfin_serial_rs_console_init);
#define BFIN_SERIAL_CONSOLE &bfin_serial_console
#else
#define BFIN_SERIAL_CONSOLE NULL
#endif /* CONFIG_SERIAL_BFIN_CONSOLE */
#ifdef CONFIG_EARLY_PRINTK
static __init void early_serial_putc(struct uart_port *port, int ch)
{
unsigned timeout = 0xffff;
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
while ((!(UART_GET_LSR(uart) & THRE)) && --timeout)
cpu_relax();
UART_PUT_CHAR(uart, ch);
}
static __init void early_serial_write(struct console *con, const char *s,
unsigned int n)
{
struct bfin_serial_port *uart = &bfin_serial_ports[con->index];
unsigned int i;
for (i = 0; i < n; i++, s++) {
if (*s == '\n')
early_serial_putc(&uart->port, '\r');
early_serial_putc(&uart->port, *s);
}
}
/*
* This should have a .setup or .early_setup in it, but then things get called
* without the command line options, and the baud rate gets messed up - so
* don't let the common infrastructure play with things. (see calls to setup
* & earlysetup in ./kernel/printk.c:register_console()
*/
static struct __initdata console bfin_early_serial_console = {
.name = "early_BFuart",
.write = early_serial_write,
.device = uart_console_device,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &bfin_serial_reg,
};
struct console __init *bfin_earlyserial_init(unsigned int port,
unsigned int cflag)
{
struct bfin_serial_port *uart;
struct ktermios t;
if (port == -1 || port >= nr_active_ports)
port = 0;
bfin_serial_init_ports();
bfin_early_serial_console.index = port;
uart = &bfin_serial_ports[port];
t.c_cflag = cflag;
t.c_iflag = 0;
t.c_oflag = 0;
t.c_lflag = ICANON;
t.c_line = port;
bfin_serial_set_termios(&uart->port, &t, &t);
return &bfin_early_serial_console;
}
#endif /* CONFIG_EARLY_PRINTK */
static struct uart_driver bfin_serial_reg = {
.owner = THIS_MODULE,
.driver_name = "bfin-uart",
.dev_name = BFIN_SERIAL_NAME,
.major = BFIN_SERIAL_MAJOR,
.minor = BFIN_SERIAL_MINOR,
.nr = BFIN_UART_NR_PORTS,
.cons = BFIN_SERIAL_CONSOLE,
};
static int bfin_serial_suspend(struct platform_device *dev, pm_message_t state)
{
int i;
for (i = 0; i < nr_active_ports; i++) {
if (bfin_serial_ports[i].port.dev != &dev->dev)
continue;
uart_suspend_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
}
return 0;
}
static int bfin_serial_resume(struct platform_device *dev)
{
int i;
for (i = 0; i < nr_active_ports; i++) {
if (bfin_serial_ports[i].port.dev != &dev->dev)
continue;
uart_resume_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
}
return 0;
}
static int bfin_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_active_ports; i++, res++) {
if (bfin_serial_ports[i].port.mapbase != res->start)
continue;
bfin_serial_ports[i].port.dev = &dev->dev;
uart_add_one_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
}
}
return 0;
}
static int bfin_serial_remove(struct platform_device *dev)
{
int i;
for (i = 0; i < nr_active_ports; i++) {
if (bfin_serial_ports[i].port.dev != &dev->dev)
continue;
uart_remove_one_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
bfin_serial_ports[i].port.dev = NULL;
#if defined(CONFIG_SERIAL_BFIN_CTSRTS) || \
defined(CONFIG_SERIAL_BFIN_HARD_CTSRTS)
gpio_free(bfin_serial_ports[i].cts_pin);
gpio_free(bfin_serial_ports[i].rts_pin);
#endif
}
return 0;
}
static struct platform_driver bfin_serial_driver = {
.probe = bfin_serial_probe,
.remove = bfin_serial_remove,
.suspend = bfin_serial_suspend,
.resume = bfin_serial_resume,
.driver = {
.name = "bfin-uart",
.owner = THIS_MODULE,
},
};
static int __init bfin_serial_init(void)
{
int ret;
pr_info("Serial: Blackfin serial driver\n");
bfin_serial_init_ports();
ret = uart_register_driver(&bfin_serial_reg);
if (ret == 0) {
ret = platform_driver_register(&bfin_serial_driver);
if (ret) {
pr_debug("uart register failed\n");
uart_unregister_driver(&bfin_serial_reg);
}
}
return ret;
}
static void __exit bfin_serial_exit(void)
{
platform_driver_unregister(&bfin_serial_driver);
uart_unregister_driver(&bfin_serial_reg);
}
module_init(bfin_serial_init);
module_exit(bfin_serial_exit);
MODULE_AUTHOR("Aubrey.Li <aubrey.li@analog.com>");
MODULE_DESCRIPTION("Blackfin generic serial port driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(BFIN_SERIAL_MAJOR);
MODULE_ALIAS("platform:bfin-uart");