From d307d36adeaa70074773b3e5eab8d7e1beb008a4 Mon Sep 17 00:00:00 2001 From: Sonic Zhang Date: Tue, 7 Apr 2009 16:52:26 +0100 Subject: 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 Signed-off-by: Bryan Wu Signed-off-by: Andrew Morton Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- drivers/serial/bfin_5xx.c | 169 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 117 insertions(+), 52 deletions(-) (limited to 'drivers/serial/bfin_5xx.c') 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_tx_chars(struct bfin_serial_port *uart); 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 @@ 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. @@ -303,6 +367,12 @@ 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); @@ -433,6 +503,13 @@ 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); @@ -481,53 +558,6 @@ static unsigned int bfin_serial_tx_empty(struct uart_port *port) 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 @@ static int bfin_serial_startup(struct uart_port *port) 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 @@ static void bfin_serial_shutdown(struct uart_port *port) 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 @@ static void __init bfin_serial_init_ports(void) 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 @@ static void __init bfin_serial_init_ports(void) 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 @@ bfin_serial_console_setup(struct console *co, char *options) 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 @@ static int bfin_serial_remove(struct platform_device *dev) 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 -- cgit v1.1