tty: Blackin CTS/RTS
Both software emulated and hardware based CTS and RTS are enabled in
serial driver.
The CTS RTS PIN connection on BF548 UART port is defined as a modem
device not as a host device. In order to test it under Linux, please
nake a cross UART cable to exchange CTS and RTS signal.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index fbbddb9..18ba812 100644
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -72,6 +72,63 @@
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
*/
@@ -108,6 +165,13 @@
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.
@@ -303,6 +367,12 @@
{
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);
@@ -433,6 +503,13 @@
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);
@@ -481,53 +558,6 @@
return 0;
}
-static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
-{
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
- struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
- if (uart->cts_pin < 0)
- return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
-
- if (UART_GET_CTS(uart))
- return TIOCM_DSR | TIOCM_CAR;
- else
-#endif
- return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
-}
-
-static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
-{
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
- struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
- if (uart->rts_pin < 0)
- return;
-
- if (mctrl & TIOCM_RTS)
- UART_CLEAR_RTS(uart);
- else
- UART_SET_RTS(uart);
-#endif
-}
-
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
-/*
- * 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);
-
- return IRQ_HANDLED;
-}
-#endif
-
-/*
- * Interrupts are always disabled.
- */
static void bfin_serial_break_ctl(struct uart_port *port, int break_state)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
@@ -660,6 +690,28 @@
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;
}
@@ -694,12 +746,20 @@
free_irq(uart->port.irq+1, uart);
#endif
-# ifdef CONFIG_SERIAL_BFIN_CTSRTS
+#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
+#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
@@ -1009,6 +1069,8 @@
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;
@@ -1019,7 +1081,8 @@
bfin_serial_resource[i].uart_rx_dma_channel;
init_timer(&(bfin_serial_ports[i].rx_dma_timer));
#endif
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+#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 =
@@ -1082,7 +1145,8 @@
int baud = 57600;
int bits = 8;
int parity = 'n';
-# ifdef CONFIG_SERIAL_BFIN_CTSRTS
+# if defined(CONFIG_SERIAL_BFIN_CTSRTS) || \
+ defined(CONFIG_SERIAL_BFIN_HARD_CTSRTS)
int flow = 'r';
# else
int flow = 'n';
@@ -1279,7 +1343,8 @@
continue;
uart_remove_one_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
bfin_serial_ports[i].port.dev = NULL;
-#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+#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