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Diffstat (limited to 'drivers/serial/bfin_5xx.c')
-rw-r--r--drivers/serial/bfin_5xx.c281
1 files changed, 136 insertions, 145 deletions
diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index ac2a3ef28d5..0aa345b9a38 100644
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -1,30 +1,11 @@
/*
- * File: drivers/serial/bfin_5xx.c
- * Based on: Based on drivers/serial/sa1100.c
- * Author: Aubrey Li <aubrey.li@analog.com>
+ * Blackfin On-Chip Serial Driver
*
- * Created:
- * Description: Driver for blackfin 5xx serial ports
+ * Copyright 2006-2007 Analog Devices Inc.
*
- * Modified:
- * Copyright 2006 Analog Devices Inc.
+ * Enter bugs at http://blackfin.uclinux.org/
*
- * Bugs: Enter bugs at http://blackfin.uclinux.org/
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see the file COPYING, or write
- * to the Free Software Foundation, Inc.,
- * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ * Licensed under the GPL-2 or later.
*/
#if defined(CONFIG_SERIAL_BFIN_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
@@ -67,14 +48,12 @@
#define DMA_RX_XCOUNT 512
#define DMA_RX_YCOUNT (PAGE_SIZE / DMA_RX_XCOUNT)
-#define DMA_RX_FLUSH_JIFFIES 5
+#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_do_work(struct work_struct *work);
static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
-static void local_put_char(struct bfin_serial_port *uart, char ch);
#endif
static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
@@ -85,23 +64,26 @@ static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
static void bfin_serial_stop_tx(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+ struct circ_buf *xmit = &uart->port.info->xmit;
+#if !defined(CONFIG_BF54x) && !defined(CONFIG_SERIAL_BFIN_DMA)
+ unsigned short ier;
+#endif
while (!(UART_GET_LSR(uart) & TEMT))
- continue;
+ 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
- /* Waiting for Transmission Finished */
- while (!(UART_GET_LSR(uart) & TFI))
- continue;
/* Clear TFI bit */
UART_PUT_LSR(uart, TFI);
UART_CLEAR_IER(uart, ETBEI);
#else
- unsigned short ier;
-
ier = UART_GET_IER(uart);
ier &= ~ETBEI;
UART_PUT_IER(uart, ier);
@@ -117,7 +99,8 @@ static void bfin_serial_start_tx(struct uart_port *port)
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
#ifdef CONFIG_SERIAL_BFIN_DMA
- bfin_serial_dma_tx_chars(uart);
+ if (uart->tx_done)
+ bfin_serial_dma_tx_chars(uart);
#else
#ifdef CONFIG_BF54x
UART_SET_IER(uart, ETBEI);
@@ -209,34 +192,27 @@ int kgdb_get_debug_char(void)
}
#endif
-#ifdef CONFIG_SERIAL_BFIN_PIO
-static void local_put_char(struct bfin_serial_port *uart, char ch)
-{
- unsigned short status;
- int flags = 0;
-
- spin_lock_irqsave(&uart->port.lock, flags);
-
- do {
- status = UART_GET_LSR(uart);
- } while (!(status & THRE));
-
- UART_PUT_CHAR(uart, ch);
- SSYNC();
-
- spin_unlock_irqrestore(&uart->port.lock, flags);
-}
+#if ANOMALY_05000230 && 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 = uart->port.info->tty;
unsigned int status, ch, flg;
- static int in_break = 0;
+ static struct timeval anomaly_start = { .tv_sec = 0 };
#ifdef CONFIG_KGDB_UART
struct pt_regs *regs = get_irq_regs();
#endif
status = UART_GET_LSR(uart);
+ UART_CLEAR_LSR(uart);
+
ch = UART_GET_CHAR(uart);
uart->port.icount.rx++;
@@ -262,28 +238,56 @@ static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
#endif
if (ANOMALY_05000230) {
- /* The BF533 family of processors have a nice misbehavior where
- * they continuously generate characters for a "single" break.
+ /* 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. All other Blackfin families operate
- * properly though.
+ * 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.
* Note: While Anomaly 05000230 does not directly address this,
* the changes that went in for it also fixed this issue.
+ * That anomaly was fixed in 0.5+ silicon. I like bunnies.
*/
- if (in_break) {
- if (ch != 0) {
- in_break = 0;
- ch = UART_GET_CHAR(uart);
- if (bfin_revid() < 5)
- return;
- } else
- return;
+ 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:
+ anomaly_start.tv_sec = 0;
}
}
if (status & BI) {
if (ANOMALY_05000230)
- in_break = 1;
+ if (bfin_revid() < 5)
+ do_gettimeofday(&anomaly_start);
uart->port.icount.brk++;
if (uart_handle_break(&uart->port))
goto ignore_char;
@@ -324,7 +328,6 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
UART_PUT_CHAR(uart, uart->port.x_char);
uart->port.icount.tx++;
uart->port.x_char = 0;
- return;
}
/*
* Check the modem control lines before
@@ -337,9 +340,12 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
return;
}
- local_put_char(uart, xmit->buf[xmit->tail]);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
- uart->port.icount.tx++;
+ 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);
@@ -352,21 +358,11 @@ static irqreturn_t bfin_serial_rx_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
-#ifdef CONFIG_BF54x
- unsigned short status;
- spin_lock(&uart->port.lock);
- status = UART_GET_LSR(uart);
- while ((UART_GET_IER(uart) & ERBFI) && (status & DR)) {
- bfin_serial_rx_chars(uart);
- status = UART_GET_LSR(uart);
- }
- spin_unlock(&uart->port.lock);
-#else
spin_lock(&uart->port.lock);
- while ((UART_GET_IIR(uart) & IIR_STATUS) == IIR_RX_READY)
+ while (UART_GET_LSR(uart) & DR)
bfin_serial_rx_chars(uart);
spin_unlock(&uart->port.lock);
-#endif
+
return IRQ_HANDLED;
}
@@ -374,25 +370,16 @@ static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
-#ifdef CONFIG_BF54x
- unsigned short status;
spin_lock(&uart->port.lock);
- status = UART_GET_LSR(uart);
- while ((UART_GET_IER(uart) & ETBEI) && (status & THRE)) {
+ if (UART_GET_LSR(uart) & THRE)
bfin_serial_tx_chars(uart);
- status = UART_GET_LSR(uart);
- }
spin_unlock(&uart->port.lock);
-#else
- spin_lock(&uart->port.lock);
- while ((UART_GET_IIR(uart) & IIR_STATUS) == IIR_TX_READY)
- bfin_serial_tx_chars(uart);
- spin_unlock(&uart->port.lock);
-#endif
+
return IRQ_HANDLED;
}
+#endif
-
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
static void bfin_serial_do_work(struct work_struct *work)
{
struct bfin_serial_port *uart = container_of(work, struct bfin_serial_port, cts_workqueue);
@@ -406,33 +393,27 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
{
struct circ_buf *xmit = &uart->port.info->xmit;
unsigned short ier;
- int flags = 0;
-
- if (!uart->tx_done)
- return;
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_done = 1;
- return;
}
+
/*
* Check the modem control lines before
* transmitting anything.
*/
bfin_serial_mctrl_check(uart);
- if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
- bfin_serial_stop_tx(&uart->port);
- uart->tx_done = 1;
- return;
- }
-
- spin_lock_irqsave(&uart->port.lock, flags);
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;
@@ -448,6 +429,7 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
set_dma_x_count(uart->tx_dma_channel, uart->tx_count);
set_dma_x_modify(uart->tx_dma_channel, 1);
enable_dma(uart->tx_dma_channel);
+
#ifdef CONFIG_BF54x
UART_SET_IER(uart, ETBEI);
#else
@@ -455,7 +437,6 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
ier |= ETBEI;
UART_PUT_IER(uart, ier);
#endif
- spin_unlock_irqrestore(&uart->port.lock, flags);
}
static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
@@ -464,7 +445,11 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
int i, flg, status;
status = UART_GET_LSR(uart);
- uart->port.icount.rx += CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail, UART_XMIT_SIZE);;
+ 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++;
@@ -490,10 +475,12 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
else
flg = TTY_NORMAL;
- for (i = uart->rx_dma_buf.head; i < uart->rx_dma_buf.tail; i++) {
- if (uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
- goto dma_ignore_char;
- uart_insert_char(&uart->port, status, OE, uart->rx_dma_buf.buf[i], flg);
+ for (i = uart->rx_dma_buf.tail; i != uart->rx_dma_buf.head; i++) {
+ if (i >= UART_XMIT_SIZE)
+ i = 0;
+ 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:
@@ -503,23 +490,23 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
{
int x_pos, pos;
- int flags = 0;
-
- bfin_serial_dma_tx_chars(uart);
- spin_lock_irqsave(&uart->port.lock, flags);
- x_pos = DMA_RX_XCOUNT - get_dma_curr_xcount(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)
+ 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;
-
- if (pos>uart->rx_dma_buf.tail) {
- uart->rx_dma_buf.tail = pos;
+ if (pos != uart->rx_dma_buf.tail) {
+ uart->rx_dma_buf.head = pos;
bfin_serial_dma_rx_chars(uart);
- uart->rx_dma_buf.head = uart->rx_dma_buf.tail;
+ uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
}
- spin_unlock_irqrestore(&uart->port.lock, flags);
+
uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
add_timer(&(uart->rx_dma_timer));
}
@@ -532,8 +519,8 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
spin_lock(&uart->port.lock);
if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
- clear_dma_irqstat(uart->tx_dma_channel);
disable_dma(uart->tx_dma_channel);
+ clear_dma_irqstat(uart->tx_dma_channel);
#ifdef CONFIG_BF54x
UART_CLEAR_IER(uart, ETBEI);
#else
@@ -541,15 +528,13 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
ier &= ~ETBEI;
UART_PUT_IER(uart, ier);
#endif
- xmit->tail = (xmit->tail+uart->tx_count) &(UART_XMIT_SIZE -1);
- uart->port.icount.tx+=uart->tx_count;
+ 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);
- if (uart_circ_empty(xmit))
- bfin_serial_stop_tx(&uart->port);
- uart->tx_done = 1;
+ bfin_serial_dma_tx_chars(uart);
}
spin_unlock(&uart->port.lock);
@@ -561,18 +546,15 @@ static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id)
struct bfin_serial_port *uart = dev_id;
unsigned short irqstat;
- uart->rx_dma_nrows++;
- if (uart->rx_dma_nrows == DMA_RX_YCOUNT) {
- uart->rx_dma_nrows = 0;
- uart->rx_dma_buf.tail = DMA_RX_XCOUNT*DMA_RX_YCOUNT;
- bfin_serial_dma_rx_chars(uart);
- uart->rx_dma_buf.head = uart->rx_dma_buf.tail = 0;
- }
spin_lock(&uart->port.lock);
irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
clear_dma_irqstat(uart->rx_dma_channel);
-
spin_unlock(&uart->port.lock);
+
+ del_timer(&(uart->rx_dma_timer));
+ uart->rx_dma_timer.expires = jiffies;
+ add_timer(&(uart->rx_dma_timer));
+
return IRQ_HANDLED;
}
#endif
@@ -599,7 +581,11 @@ static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
if (uart->cts_pin < 0)
return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+# ifdef BF54x
+ if (UART_GET_MSR(uart) & CTS)
+# else
if (gpio_get_value(uart->cts_pin))
+# endif
return TIOCM_DSR | TIOCM_CAR;
else
#endif
@@ -614,9 +600,17 @@ static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
return;
if (mctrl & TIOCM_RTS)
+# ifdef BF54x
+ UART_PUT_MCR(uart, UART_GET_MCR(uart) & ~MRTS);
+# else
gpio_set_value(uart->rts_pin, 0);
+# endif
else
+# ifdef BF54x
+ UART_PUT_MCR(uart, UART_GET_MCR(uart) | MRTS);
+# else
gpio_set_value(uart->rts_pin, 1);
+# endif
#endif
}
@@ -627,22 +621,17 @@ static void bfin_serial_mctrl_check(struct bfin_serial_port *uart)
{
#ifdef CONFIG_SERIAL_BFIN_CTSRTS
unsigned int status;
-# ifdef CONFIG_SERIAL_BFIN_DMA
struct uart_info *info = uart->port.info;
struct tty_struct *tty = info->tty;
status = bfin_serial_get_mctrl(&uart->port);
+ uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
if (!(status & TIOCM_CTS)) {
tty->hw_stopped = 1;
+ schedule_work(&uart->cts_workqueue);
} else {
tty->hw_stopped = 0;
}
-# else
- status = bfin_serial_get_mctrl(&uart->port);
- uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
- if (!(status & TIOCM_CTS))
- schedule_work(&uart->cts_workqueue);
-# endif
#endif
}
@@ -743,6 +732,7 @@ static void bfin_serial_shutdown(struct uart_port *port)
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_KGDB_UART
if (uart->port.line != CONFIG_KGDB_UART_PORT)
@@ -814,6 +804,8 @@ bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
quot = uart_get_divisor(port, baud);
spin_lock_irqsave(&uart->port.lock, flags);
+ UART_SET_ANOMALY_THRESHOLD(uart, USEC_PER_SEC / baud * 15);
+
do {
lsr = UART_GET_LSR(uart);
} while (!(lsr & TEMT));
@@ -956,10 +948,9 @@ static void __init bfin_serial_init_ports(void)
bfin_serial_ports[i].rx_dma_channel =
bfin_serial_resource[i].uart_rx_dma_channel;
init_timer(&(bfin_serial_ports[i].rx_dma_timer));
-#else
- INIT_WORK(&bfin_serial_ports[i].cts_workqueue, bfin_serial_do_work);
#endif
#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+ INIT_WORK(&bfin_serial_ports[i].cts_workqueue, bfin_serial_do_work);
bfin_serial_ports[i].cts_pin =
bfin_serial_resource[i].uart_cts_pin;
bfin_serial_ports[i].rts_pin =
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-14 08:24:34 +0000