From fea34b144e98c7808918197330522afb5d6944b4 Mon Sep 17 00:00:00 2001 From: michael musset Date: Mon, 27 Jul 2015 16:57:29 +0200 Subject: [PATCH] modified: drivers/tty/serial/omap-serial.c the change detect better the end of transmission. ( it happens for long frame to change the RTS before the end of the frame ) --- drivers/tty/serial/omap-serial.c | 82 ++++++++++++++++++++++++++------------ 1 file changed, 56 insertions(+), 26 deletions(-) diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index c57e5bd..f715d21 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -20,6 +20,8 @@ * this driver as required for the omap-platform. */ +#define RS485_VERSION "rs485 v1.2" + #if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) #define SUPPORT_SYSRQ #endif @@ -270,31 +272,57 @@ static void serial_omap_enable_ms(struct uart_port *port) pm_runtime_mark_last_busy(up->dev); pm_runtime_put_autosuspend(up->dev); } -static inline void wait_for_xmitr(struct uart_omap_port *up); static void serial_omap_stop_tx(struct uart_port *port) { struct uart_omap_port *up = to_uart_omap_port(port); int val; pm_runtime_get_sync(up->dev); - if (up->ier & UART_IER_THRI) { - up->ier &= ~UART_IER_THRI; - serial_out(up, UART_IER, up->ier); - } - serial_omap_set_forceidle(up); - - pm_runtime_mark_last_busy(up->dev); - pm_runtime_put_autosuspend(up->dev); - wait_for_xmitr(up); + //wait_for_xmitr(up); if (up->rs485.flags & SER_RS485_ENABLED) { - if(up->rs485.delay_rts_after_send>0) { - udelay(up->rs485.delay_rts_after_send); + if (up->scr & OMAP_UART_SCR_TX_EMPTY) { + /* THR interrupt is fired when both TX FIFO and TX + * shift register are empty. This means there's nothing + * left to transmit now, so make sure the THR interrupt + * is fired when TX FIFO is below the trigger level, + * disable THR interrupts and toggle the RS-485 GPIO + * data direction pin if needed. + */ + up->scr &= ~OMAP_UART_SCR_TX_EMPTY; + serial_out(up, UART_OMAP_SCR, up->scr); + + val = (up->rs485.flags & SER_RS485_RTS_AFTER_SEND) ? 1 : 0; + if (gpio_get_value(up->rs485.gpio_pin) != val) { + if(up->rs485.delay_rts_after_send>0) { + udelay(up->rs485.delay_rts_after_send); + } + /* Disable RS485 TX EN */ + gpio_set_value(up->rs485.gpio_pin, val); + } + }else{ + /* We're asked to stop, but there's still stuff in the + * UART FIFO, so make sure the THR interrupt is fired + * when both TX FIFO and TX shift register are empty. + * The next THR interrupt (if no transmission is started + * in the meantime) will indicate the end of a + * transmission. Therefore we _don't_ disable THR + * interrupts in this situation. + */ + up->scr |= OMAP_UART_SCR_TX_EMPTY; + serial_out(up, UART_OMAP_SCR, up->scr); + return; } - /* Disable RS485 TX EN */ - val = (up->rs485.flags & SER_RS485_RTS_AFTER_SEND) ? 1 : 0; - gpio_set_value(up->rs485.gpio_pin, val); } + + if (up->ier & UART_IER_THRI) { + up->ier &= ~UART_IER_THRI; + serial_out(up, UART_IER, up->ier); + } + + serial_omap_set_forceidle(up); + pm_runtime_mark_last_busy(up->dev); + pm_runtime_put_autosuspend(up->dev); } static void serial_omap_stop_rx(struct uart_port *port) @@ -354,21 +382,23 @@ static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up) } } -static void serial_omap_start_tx(struct uart_port *port) -{ +static void serial_omap_start_tx(struct uart_port *port){ struct uart_omap_port *up = to_uart_omap_port(port); int val; - + pm_runtime_get_sync(up->dev); if (up->rs485.flags & SER_RS485_ENABLED) { + /* Fire THR interrupts when FIFO is below trigger level */ + up->scr &= ~OMAP_UART_SCR_TX_EMPTY; + serial_out(up, UART_OMAP_SCR, up->scr); + /* if rts not already enabled */ /* Enable RS485 TX EN */ val = (up->rs485.flags & SER_RS485_RTS_ON_SEND) ? 0 : 1; - gpio_set_value(up->rs485.gpio_pin, val); - - if(up->rs485.delay_rts_before_send>0) - udelay(up->rs485.delay_rts_before_send); + if (gpio_get_value(up->rs485.gpio_pin) != val) { + gpio_set_value(up->rs485.gpio_pin, val); + if(up->rs485.delay_rts_before_send>0) + udelay(up->rs485.delay_rts_before_send); + } } - - pm_runtime_get_sync(up->dev); serial_omap_enable_ier_thri(up); serial_omap_set_noidle(up); pm_runtime_mark_last_busy(up->dev); @@ -1342,7 +1372,7 @@ serial_omap_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg) struct serial_rs485 rs485conf; switch (cmd) { case TIOCSRS485: - printk("rs485 v1.1\n"); + printk(RS485_VERSION); if (copy_from_user(&rs485conf, (struct serial_rs485 *)arg, sizeof(rs485conf))) return -EFAULT; @@ -1350,7 +1380,7 @@ serial_omap_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg) break; case TIOCGRS485: - printk("rs485 v1.1\n"); + printk(RS485_VERSION); if (copy_to_user((struct serial_rs485 *)arg, &((struct uart_omap_port *)port)->rs485, sizeof(rs485conf))) -- 1.7.9.5