From 1f7d1c85df5b63359e7f7e3fbd1509c1cdd6414f Mon Sep 17 00:00:00 2001 From: Sonic Zhang Date: Tue, 9 Mar 2010 12:25:33 -0500 Subject: [PATCH] serial: bfin_sport_uart: add support for CTS/RTS via GPIOs Some people need flow control on their ports, so now boards can support that via any GPIOs. Signed-off-by: Sonic Zhang Signed-off-by: Mike Frysinger Signed-off-by: Greg Kroah-Hartman --- drivers/serial/Kconfig | 24 +++++++ drivers/serial/bfin_sport_uart.c | 111 ++++++++++++++++++++++++++++--- drivers/serial/bfin_sport_uart.h | 11 +++ 3 files changed, 135 insertions(+), 11 deletions(-) diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 302836a80693..63258305c057 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -1443,24 +1443,48 @@ config SERIAL_BFIN_SPORT0_UART help Enable UART over SPORT0 +config SERIAL_BFIN_SPORT0_UART_CTSRTS + bool "Enable UART over SPORT0 hardware flow control" + depends on SERIAL_BFIN_SPORT0_UART + help + Enable hardware flow control in the driver. + config SERIAL_BFIN_SPORT1_UART bool "Enable UART over SPORT1" depends on SERIAL_BFIN_SPORT help Enable UART over SPORT1 +config SERIAL_BFIN_SPORT1_UART_CTSRTS + bool "Enable UART over SPORT1 hardware flow control" + depends on SERIAL_BFIN_SPORT1_UART + help + Enable hardware flow control in the driver. + config SERIAL_BFIN_SPORT2_UART bool "Enable UART over SPORT2" depends on SERIAL_BFIN_SPORT && (BF54x || BF538 || BF539) help Enable UART over SPORT2 +config SERIAL_BFIN_SPORT2_UART_CTSRTS + bool "Enable UART over SPORT2 hardware flow control" + depends on SERIAL_BFIN_SPORT2_UART + help + Enable hardware flow control in the driver. + config SERIAL_BFIN_SPORT3_UART bool "Enable UART over SPORT3" depends on SERIAL_BFIN_SPORT && (BF54x || BF538 || BF539) help Enable UART over SPORT3 +config SERIAL_BFIN_SPORT3_UART_CTSRTS + bool "Enable UART over SPORT3 hardware flow control" + depends on SERIAL_BFIN_SPORT3_UART + help + Enable hardware flow control in the driver. + config SERIAL_TIMBERDALE tristate "Support for timberdale UART" select SERIAL_CORE diff --git a/drivers/serial/bfin_sport_uart.c b/drivers/serial/bfin_sport_uart.c index 79252664f706..8cb0a40c2baa 100644 --- a/drivers/serial/bfin_sport_uart.c +++ b/drivers/serial/bfin_sport_uart.c @@ -48,6 +48,10 @@ struct sport_uart_port { unsigned short txmask2; unsigned char stopb; /* unsigned char parib; */ +#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS + int cts_pin; + int rts_pin; +#endif }; static void sport_uart_tx_chars(struct sport_uart_port *up); @@ -198,6 +202,59 @@ static irqreturn_t sport_uart_err_irq(int irq, void *dev_id) return IRQ_HANDLED; } +#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS +static unsigned int sport_get_mctrl(struct uart_port *port) +{ + struct sport_uart_port *up = (struct sport_uart_port *)port; + if (up->cts_pin < 0) + return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR; + + /* CTS PIN is negative assertive. */ + if (SPORT_UART_GET_CTS(up)) + return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR; + else + return TIOCM_DSR | TIOCM_CAR; +} + +static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + struct sport_uart_port *up = (struct sport_uart_port *)port; + if (up->rts_pin < 0) + return; + + /* RTS PIN is negative assertive. */ + if (mctrl & TIOCM_RTS) + SPORT_UART_ENABLE_RTS(up); + else + SPORT_UART_DISABLE_RTS(up); +} + +/* + * Handle any change of modem status signal. + */ +static irqreturn_t sport_mctrl_cts_int(int irq, void *dev_id) +{ + struct sport_uart_port *up = (struct sport_uart_port *)dev_id; + unsigned int status; + + status = sport_get_mctrl(&up->port); + uart_handle_cts_change(&up->port, status & TIOCM_CTS); + + return IRQ_HANDLED; +} +#else +static unsigned int sport_get_mctrl(struct uart_port *port) +{ + pr_debug("%s enter\n", __func__); + return TIOCM_CTS | TIOCM_CD | TIOCM_DSR; +} + +static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + pr_debug("%s enter\n", __func__); +} +#endif + /* Reqeust IRQ, Setup clock */ static int sport_startup(struct uart_port *port) { @@ -226,6 +283,21 @@ static int sport_startup(struct uart_port *port) goto fail2; } +#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS + if (up->cts_pin >= 0) { + if (request_irq(gpio_to_irq(up->cts_pin), + sport_mctrl_cts_int, + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | + IRQF_DISABLED, "BFIN_SPORT_UART_CTS", up)) { + up->cts_pin = -1; + dev_info(port->dev, "Unable to attach BlackFin UART \ + over SPORT CTS interrupt. So, disable it.\n"); + } + } + if (up->rts_pin >= 0) + gpio_direction_output(up->rts_pin, 0); +#endif + return 0; fail2: free_irq(up->port.irq+1, up); @@ -283,17 +355,6 @@ static unsigned int sport_tx_empty(struct uart_port *port) return 0; } -static unsigned int sport_get_mctrl(struct uart_port *port) -{ - pr_debug("%s enter\n", __func__); - return (TIOCM_CTS | TIOCM_CD | TIOCM_DSR); -} - -static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl) -{ - pr_debug("%s enter\n", __func__); -} - static void sport_stop_tx(struct uart_port *port) { struct sport_uart_port *up = (struct sport_uart_port *)port; @@ -364,6 +425,10 @@ static void sport_shutdown(struct uart_port *port) free_irq(up->port.irq, up); free_irq(up->port.irq+1, up); free_irq(up->err_irq, up); +#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS + if (up->cts_pin >= 0) + free_irq(gpio_to_irq(up->cts_pin), up); +#endif } static const char *sport_type(struct uart_port *port) @@ -536,7 +601,11 @@ sport_uart_console_setup(struct console *co, char *options) int baud = 57600; int bits = 8; int parity = 'n'; +# ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS + int flow = 'r'; +# else int flow = 'n'; +# endif /* Check whether an invalid uart number has been specified */ if (co->index < 0 || co->index >= BFIN_SPORT_UART_MAX_PORTS) @@ -729,6 +798,22 @@ static int __devinit sport_uart_probe(struct platform_device *pdev) ret = -ENOENT; goto out_error_unmap; } +#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS + res = platform_get_resource(pdev, IORESOURCE_IO, 0); + if (res == NULL) + sport->cts_pin = -1; + else + sport->cts_pin = res->start; + + res = platform_get_resource(pdev, IORESOURCE_IO, 1); + if (res == NULL) + sport->rts_pin = -1; + else + sport->rts_pin = res->start; + + if (sport->rts_pin >= 0) + gpio_request(sport->rts_pin, DRV_NAME); +#endif } #ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE @@ -767,6 +852,10 @@ static int __devexit sport_uart_remove(struct platform_device *pdev) if (sport) { uart_remove_one_port(&sport_uart_reg, &sport->port); +#ifdef CONFIG_SERIAL_BFIN_CTSRTS + if (sport->rts_pin >= 0) + gpio_free(sport->rts_pin); +#endif iounmap(sport->port.membase); peripheral_free_list( (unsigned short *)pdev->dev.platform_data); diff --git a/drivers/serial/bfin_sport_uart.h b/drivers/serial/bfin_sport_uart.h index 9791fcc80a74..9ce253e381d2 100644 --- a/drivers/serial/bfin_sport_uart.h +++ b/drivers/serial/bfin_sport_uart.h @@ -72,4 +72,15 @@ #define SPORT_TX_FIFO_SIZE 8 +#define SPORT_UART_GET_CTS(x) gpio_get_value(x->cts_pin) +#define SPORT_UART_DISABLE_RTS(x) gpio_set_value(x->rts_pin, 1) +#define SPORT_UART_ENABLE_RTS(x) gpio_set_value(x->rts_pin, 0) + +#if defined(CONFIG_SERIAL_BFIN_SPORT0_UART_CTSRTS) \ + || defined(CONFIG_SERIAL_BFIN_SPORT1_UART_CTSRTS) \ + || defined(CONFIG_SERIAL_BFIN_SPORT2_UART_CTSRTS) \ + || defined(CONFIG_SERIAL_BFIN_SPORT3_UART_CTSRTS) +# define CONFIG_SERIAL_BFIN_SPORT_CTSRTS +#endif + #endif /* _BFIN_SPORT_UART_H */ -- 2.30.2