This patch adds TIA/EIA-485 standard support to OMAP-UART controller driver by adding handlers for TIOCSRS485 and TIOCGRS485 ioctl commands.
This patch is based on Ilya Yanok <[email protected]> patch [1] but it changes the function serial_omap_update_rts() that raises and lows the Ready-to-Send control signal. Also, it forces to update the RTS signal when the serial-core calls serial_omap_set_mctrl(). [1]: http://www.spinics.net/lists/linux-omap/msg58546.html Signed-off-by: Javier Martinez Canillas <[email protected]> --- arch/arm/plat-omap/include/plat/omap-serial.h | 2 + drivers/tty/serial/Makefile | 2 +- drivers/tty/serial/omap-serial.c | 139 ++++++++++++++++++++++-- include/linux/serial_reg.h | 2 + 4 files changed, 132 insertions(+), 13 deletions(-) diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h index 2682043..b7c2c29 100644 --- a/arch/arm/plat-omap/include/plat/omap-serial.h +++ b/arch/arm/plat-omap/include/plat/omap-serial.h @@ -111,6 +111,8 @@ struct uart_omap_port { unsigned char msr_saved_flags; char name[20]; unsigned long port_activity; + struct serial_rs485 rs485; + unsigned int tx_in_progress:1, tx_wait_end:1; }; #endif /* __OMAP_SERIAL_H__ */ diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index 83b4da6..865f238 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -71,7 +71,7 @@ obj-$(CONFIG_SERIAL_VR41XX) += vr41xx_siu.o obj-$(CONFIG_SERIAL_SGI_IOC4) += ioc4_serial.o obj-$(CONFIG_SERIAL_SGI_IOC3) += ioc3_serial.o obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o -obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o +#obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o obj-$(CONFIG_SERIAL_MSM) += msm_serial.o obj-$(CONFIG_SERIAL_MSM_HS) += msm_serial_hs.o obj-$(CONFIG_SERIAL_NETX) += netx-serial.o diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 5e713d3..d1789f4 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -37,6 +37,7 @@ #include <linux/clk.h> #include <linux/serial_core.h> #include <linux/irq.h> +#include <linux/uaccess.h> #include <plat/dma.h> #include <plat/dmtimer.h> @@ -114,6 +115,56 @@ static void serial_omap_enable_ms(struct uart_port *port) serial_out(up, UART_IER, up->ier); } +static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up) +{ + if (!(up->ier & UART_IER_THRI)) { + up->ier |= UART_IER_THRI; + serial_out(up, UART_IER, up->ier); + } +} + +static inline void serial_omap_disable_ier_thri(struct uart_omap_port *up) +{ + if (up->ier & UART_IER_THRI) { + up->ier &= ~UART_IER_THRI; + serial_out(up, UART_IER, up->ier); + } +} + +static inline void serial_omap_thri_mode(struct uart_omap_port *up) +{ + unsigned char scr = serial_in(up, UART_OMAP_SCR); + + if (up->tx_wait_end) + scr |= UART_OMAP_SCR_TX_EMPTY_CTL_IT; + else + scr &= ~UART_OMAP_SCR_TX_EMPTY_CTL_IT; + serial_out(up, UART_OMAP_SCR, scr); +} + + +static inline void serial_omap_update_rts(struct uart_omap_port *up) +{ + unsigned char mcr = up->mcr; + int rts_on_send = up->rs485.flags & SER_RS485_RTS_ON_SEND; + + if (up->rs485.flags & SER_RS485_ENABLED) { + if (up->tx_in_progress) { + if (rts_on_send) + mcr |= UART_MCR_RTS; + else + mcr &= ~UART_MCR_RTS; + } else { + if (rts_on_send) + mcr &= ~UART_MCR_RTS; + else + mcr |= ~UART_MCR_RTS; + } + } + + serial_out(up, UART_MCR, mcr); +} + static void serial_omap_stop_tx(struct uart_port *port) { struct uart_omap_port *up = (struct uart_omap_port *)port; @@ -131,9 +182,14 @@ static void serial_omap_stop_tx(struct uart_port *port) up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE; } - if (up->ier & UART_IER_THRI) { - up->ier &= ~UART_IER_THRI; - serial_out(up, UART_IER, up->ier); + if (!(up->rs485.flags & SER_RS485_ENABLED)) + serial_omap_disable_ier_thri(up); + else { + up->tx_in_progress = 0; + serial_omap_update_rts(up); + up->tx_wait_end = 1; + serial_omap_thri_mode(up); + serial_omap_enable_ier_thri(up); } } @@ -246,14 +302,6 @@ static void transmit_chars(struct uart_omap_port *up) serial_omap_stop_tx(&up->port); } -static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up) -{ - if (!(up->ier & UART_IER_THRI)) { - up->ier |= UART_IER_THRI; - serial_out(up, UART_IER, up->ier); - } -} - static void serial_omap_start_tx(struct uart_port *port) { struct uart_omap_port *up = (struct uart_omap_port *)port; @@ -261,6 +309,18 @@ static void serial_omap_start_tx(struct uart_port *port) unsigned int start; int ret = 0; + if (up->rs485.flags & SER_RS485_ENABLED) { + if (!up->tx_in_progress) { + up->tx_in_progress = 1; + serial_omap_update_rts(up); + } + if (up->tx_wait_end) { + up->tx_wait_end = 0; + serial_omap_thri_mode(up); + serial_omap_disable_ier_thri(up); + } + } + if (!up->use_dma) { serial_omap_enable_ier_thri(up); return; @@ -343,6 +403,11 @@ static unsigned int check_modem_status(struct uart_omap_port *up) return status; } +static inline unsigned int __serial_omap_tx_empty(struct uart_omap_port *up) +{ + return serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0; +} + /** * serial_omap_irq() - This handles the interrupt from one port * @irq: uart port irq number @@ -359,6 +424,16 @@ static inline irqreturn_t serial_omap_irq(int irq, void *dev_id) return IRQ_NONE; spin_lock_irqsave(&up->port.lock, flags); + if (up->tx_wait_end && (iir & UART_IIR_THRI) && + __serial_omap_tx_empty(up)) { + up->tx_wait_end = 0; + up->tx_in_progress = 0; + serial_omap_thri_mode(up); + serial_omap_update_rts(up); + serial_omap_disable_ier_thri(up); + spin_unlock_irqrestore(&up->port.lock, flags); + return IRQ_HANDLED; + } lsr = serial_in(up, UART_LSR); if (iir & UART_IIR_RLSI) { if (!up->use_dma) { @@ -390,7 +465,7 @@ static unsigned int serial_omap_tx_empty(struct uart_port *port) dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->pdev->id); spin_lock_irqsave(&up->port.lock, flags); - ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0; + ret = __serial_omap_tx_empty(up); spin_unlock_irqrestore(&up->port.lock, flags); return ret; @@ -434,6 +509,10 @@ static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl) mcr |= UART_MCR_LOOP; mcr |= up->mcr; + + if (up->rs485.flags & SER_RS485_ENABLED) + serial_omap_update_rts(up); + serial_out(up, UART_MCR, mcr); } @@ -1028,6 +1107,41 @@ static inline void serial_omap_add_console_port(struct uart_omap_port *up) #endif +static int +serial_omap_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg) +{ + struct serial_rs485 rs485conf; + struct uart_omap_port *up = (struct uart_omap_port *)port; + unsigned long flags; + + switch (cmd) { + case TIOCSRS485: + if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg, + sizeof(rs485conf))) + return -EFAULT; + + spin_lock_irqsave(&up->port.lock, flags); + if (!(rs485conf.flags & SER_RS485_ENABLED)) { + up->tx_in_progress = 0; + up->tx_wait_end = 0; + } + up->rs485 = rs485conf; + serial_omap_update_rts(up); + serial_omap_thri_mode(up); + spin_unlock_irqrestore(&up->port.lock, flags); + + case TIOCGRS485: + if (copy_to_user((struct serial_rs485 *) arg, + &(up->rs485), sizeof(rs485conf))) + return -EFAULT; + break; + + default: + return -ENOIOCTLCMD; + } + return 0; +} + static struct uart_ops serial_omap_pops = { .tx_empty = serial_omap_tx_empty, .set_mctrl = serial_omap_set_mctrl, @@ -1041,6 +1155,7 @@ static struct uart_ops serial_omap_pops = { .shutdown = serial_omap_shutdown, .set_termios = serial_omap_set_termios, .pm = serial_omap_pm, + .ioctl = serial_omap_ioctl, .type = serial_omap_type, .release_port = serial_omap_release_port, .request_port = serial_omap_request_port, diff --git a/include/linux/serial_reg.h b/include/linux/serial_reg.h index c75bda3..dc6a3f7 100644 --- a/include/linux/serial_reg.h +++ b/include/linux/serial_reg.h @@ -362,5 +362,7 @@ #define UART_OMAP_MDR1_CIR_MODE 0x06 /* CIR mode */ #define UART_OMAP_MDR1_DISABLE 0x07 /* Disable (default state) */ +#define UART_OMAP_SCR_TX_EMPTY_CTL_IT 0x04 /* TX Empty IRQ mode */ + #endif /* _LINUX_SERIAL_REG_H */ -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
