* [PATCH 04/18] Blackfin Serial Driver: Change hardware flowcontrol from poll to interrupt driven. - v2
@ 2009-03-10 9:54 sonic zhang
0 siblings, 0 replies; only message in thread
From: sonic zhang @ 2009-03-10 9:54 UTC (permalink / raw)
To: Alan Cox; +Cc: Linux Kernel, Bryan Wu
Current implementation is polling (busy waiting), the
kernel will basically hang when the remote asserts hardware
flowcontrol pins. if this is only asserted for short periods (less
than 1 char time), then it's not really noticed. This patch changes
flowcontrol CTS into interrupt driven.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
---
.../mach-bf527/include/mach/bfin_serial_5xx.h | 26 ----
.../mach-bf533/include/mach/bfin_serial_5xx.h | 20 ---
.../mach-bf537/include/mach/bfin_serial_5xx.h | 27 ----
.../mach-bf548/include/mach/bfin_serial_5xx.h | 45 -------
.../mach-bf561/include/mach/bfin_serial_5xx.h | 20 ---
drivers/serial/bfin_5xx.c | 131 ++++++++++++--------
6 files changed, 82 insertions(+), 187 deletions(-)
diff --git a/arch/blackfin/mach-bf527/include/mach/bfin_serial_5xx.h b/arch/blackfin/mach-bf527/include/mach/bfin_serial_5xx.h
index e8c41fd..d2b160c 100644
--- a/arch/blackfin/mach-bf527/include/mach/bfin_serial_5xx.h
+++ b/arch/blackfin/mach-bf527/include/mach/bfin_serial_5xx.h
@@ -167,29 +167,3 @@ struct bfin_serial_res bfin_serial_resource[] = {
};
#define DRIVER_NAME "bfin-uart"
-
-static void bfin_serial_hw_init(struct bfin_serial_port *uart)
-{
-
-#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);
-#endif
-
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
- if (uart->cts_pin >= 0) {
- gpio_request(uart->cts_pin, DRIVER_NAME);
- gpio_direction_input(uart->cts_pin);
- }
-
- if (uart->rts_pin >= 0) {
- gpio_request(uart->rts_pin, DRIVER_NAME);
- gpio_direction_output(uart->rts_pin, 0);
- }
-#endif
-}
diff --git a/arch/blackfin/mach-bf533/include/mach/bfin_serial_5xx.h b/arch/blackfin/mach-bf533/include/mach/bfin_serial_5xx.h
index 5f517f5..70356dd 100644
--- a/arch/blackfin/mach-bf533/include/mach/bfin_serial_5xx.h
+++ b/arch/blackfin/mach-bf533/include/mach/bfin_serial_5xx.h
@@ -142,23 +142,3 @@ struct bfin_serial_res bfin_serial_resource[] = {
};
#define DRIVER_NAME "bfin-uart"
-
-static void bfin_serial_hw_init(struct bfin_serial_port *uart)
-{
-
-#ifdef CONFIG_SERIAL_BFIN_UART0
- peripheral_request(P_UART0_TX, DRIVER_NAME);
- peripheral_request(P_UART0_RX, DRIVER_NAME);
-#endif
-
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
- if (uart->cts_pin >= 0) {
- gpio_request(uart->cts_pin, DRIVER_NAME);
- gpio_direction_input(uart->cts_pin);
- }
- if (uart->rts_pin >= 0) {
- gpio_request(uart->rts_pin, DRIVER_NAME);
- gpio_direction_output(uart->rts_pin, 0);
- }
-#endif
-}
diff --git a/arch/blackfin/mach-bf537/include/mach/bfin_serial_5xx.h b/arch/blackfin/mach-bf537/include/mach/bfin_serial_5xx.h
index 9e34700..d46fc4f 100644
--- a/arch/blackfin/mach-bf537/include/mach/bfin_serial_5xx.h
+++ b/arch/blackfin/mach-bf537/include/mach/bfin_serial_5xx.h
@@ -99,7 +99,6 @@ struct bfin_serial_port {
struct work_struct tx_dma_workqueue;
#endif
#ifdef CONFIG_SERIAL_BFIN_CTSRTS
- struct timer_list cts_timer;
int cts_pin;
int rts_pin;
#endif
@@ -167,29 +166,3 @@ struct bfin_serial_res bfin_serial_resource[] = {
};
#define DRIVER_NAME "bfin-uart"
-
-static void bfin_serial_hw_init(struct bfin_serial_port *uart)
-{
-
-#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);
-#endif
-
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
- if (uart->cts_pin >= 0) {
- gpio_request(uart->cts_pin, DRIVER_NAME);
- gpio_direction_input(uart->cts_pin);
- }
-
- if (uart->rts_pin >= 0) {
- gpio_request(uart->rts_pin, DRIVER_NAME);
- gpio_direction_output(uart->rts_pin, 0);
- }
-#endif
-}
diff --git a/arch/blackfin/mach-bf548/include/mach/bfin_serial_5xx.h b/arch/blackfin/mach-bf548/include/mach/bfin_serial_5xx.h
index c05e79c..388e232 100644
--- a/arch/blackfin/mach-bf548/include/mach/bfin_serial_5xx.h
+++ b/arch/blackfin/mach-bf548/include/mach/bfin_serial_5xx.h
@@ -181,48 +181,3 @@ struct bfin_serial_res bfin_serial_resource[] = {
};
#define DRIVER_NAME "bfin-uart"
-
-static void bfin_serial_hw_init(struct bfin_serial_port *uart)
-{
-#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);
-
-#ifdef CONFIG_BFIN_UART1_CTSRTS
- 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);
-
-#ifdef CONFIG_BFIN_UART3_CTSRTS
- peripheral_request(P_UART3_RTS, DRIVER_NAME);
- peripheral_request(P_UART3_CTS, DRIVER_NAME);
-#endif
-#endif
- SSYNC();
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
- if (uart->cts_pin >= 0) {
- gpio_request(uart->cts_pin, DRIVER_NAME);
- gpio_direction_input(uart->cts_pin);
- }
-
- if (uart->rts_pin >= 0) {
- gpio_request(uart->rts_pin, DRIVER_NAME);
- gpio_direction_output(uart->rts_pin, 0);
- }
-#endif
-}
diff --git a/arch/blackfin/mach-bf561/include/mach/bfin_serial_5xx.h b/arch/blackfin/mach-bf561/include/mach/bfin_serial_5xx.h
index ca8c5f6..d0469e3 100644
--- a/arch/blackfin/mach-bf561/include/mach/bfin_serial_5xx.h
+++ b/arch/blackfin/mach-bf561/include/mach/bfin_serial_5xx.h
@@ -142,23 +142,3 @@ struct bfin_serial_res bfin_serial_resource[] = {
};
#define DRIVER_NAME "bfin-uart"
-
-static void bfin_serial_hw_init(struct bfin_serial_port *uart)
-{
-
-#ifdef CONFIG_SERIAL_BFIN_UART0
- peripheral_request(P_UART0_TX, DRIVER_NAME);
- peripheral_request(P_UART0_RX, DRIVER_NAME);
-#endif
-
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
- if (uart->cts_pin >= 0) {
- gpio_request(uart->cts_pin, DRIVER_NAME);
- gpio_direction_input(uart->cts_pin);
- }
- if (uart->rts_pin >= 0) {
- gpio_request(uart->rts_pin, DRIVER_NAME);
- gpio_direction_output(uart->rts_pin, 0);
- }
-#endif
-}
diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index 1e027e3..8d34ccd 100644
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -64,7 +64,6 @@ static int kgdboc_break_enabled;
#define DMA_RX_YCOUNT (PAGE_SIZE / DMA_RX_XCOUNT)
#define DMA_RX_FLUSH_JIFFIES (HZ / 50)
-#define CTS_CHECK_JIFFIES (HZ / 50)
#ifdef CONFIG_SERIAL_BFIN_DMA
static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
@@ -72,8 +71,6 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
#endif
-static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
-
static void bfin_serial_reset_irda(struct uart_port *port);
/*
@@ -265,12 +262,6 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
{
struct circ_buf *xmit = &uart->port.info->xmit;
- /*
- * Check the modem control lines before
- * transmitting anything.
- */
- bfin_serial_mctrl_check(uart);
-
if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
#ifdef CONFIG_BF54x
/* Clear TFI bit */
@@ -329,12 +320,6 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
uart->tx_done = 0;
- /*
- * Check the modem control lines before
- * transmitting anything.
- */
- bfin_serial_mctrl_check(uart);
-
if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
uart->tx_count = 0;
uart->tx_done = 1;
@@ -524,29 +509,21 @@ static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
#endif
}
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
/*
- * Handle any change of modem status signal since we were last called.
+ * Handle any change of modem status signal.
*/
-static void bfin_serial_mctrl_check(struct bfin_serial_port *uart)
+static irqreturn_t bfin_serial_mctrl_cts_int(int irq, void *dev_id)
{
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+ struct bfin_serial_port *uart = dev_id;
unsigned int status;
- struct uart_info *info = uart->port.info;
- struct tty_struct *tty = info->port.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;
- uart->cts_timer.data = (unsigned long)(uart);
- uart->cts_timer.function = (void *)bfin_serial_mctrl_check;
- uart->cts_timer.expires = jiffies + CTS_CHECK_JIFFIES;
- add_timer(&(uart->cts_timer));
- } else {
- tty->hw_stopped = 0;
- }
-#endif
+
+ return IRQ_HANDLED;
}
+#endif
/*
* Interrupts are always disabled.
@@ -606,7 +583,7 @@ static int bfin_serial_startup(struct uart_port *port)
uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
add_timer(&(uart->rx_dma_timer));
#else
-#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
+# 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;
@@ -661,11 +638,28 @@ static int bfin_serial_startup(struct uart_port *port)
}
}
# endif
-#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
+# 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
UART_SET_IER(uart, ERBFI);
return 0;
}
@@ -699,6 +693,13 @@ static void bfin_serial_shutdown(struct uart_port *port)
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
}
static void
@@ -864,6 +865,20 @@ static void bfin_serial_set_ldisc(struct uart_port *port)
}
}
+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
static void bfin_serial_poll_put_char(struct uart_port *port, unsigned char chr)
{
@@ -909,20 +924,6 @@ static int bfin_kgdboc_port_startup(struct uart_port *port)
}
#endif
-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();
-}
-
static struct uart_ops bfin_serial_pops = {
.tx_empty = bfin_serial_tx_empty,
.set_mctrl = bfin_serial_set_mctrl,
@@ -952,6 +953,39 @@ static struct uart_ops bfin_serial_pops = {
#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;
@@ -961,6 +995,8 @@ static void __init bfin_serial_init_ports(void)
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;
@@ -984,15 +1020,12 @@ static void __init bfin_serial_init_ports(void)
init_timer(&(bfin_serial_ports[i].rx_dma_timer));
#endif
#ifdef CONFIG_SERIAL_BFIN_CTSRTS
- init_timer(&(bfin_serial_ports[i].cts_timer));
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
- bfin_serial_hw_init(&bfin_serial_ports[i]);
}
-
}
#if defined(CONFIG_SERIAL_BFIN_CONSOLE) || defined(CONFIG_EARLY_PRINTK)
--
1.6.0
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