From: Javier Martinez Canillas <martinez.javier@gmail.com>
To: Tony Lindgren <tony@atomide.com>
Cc: Alan Cox <alan@linux.intel.com>,
Govindraj Raja <govindraj.raja@ti.com>,
linux-omap@vger.kernel.org, linux-serial@vger.kernel.org,
Javier Martinez Canillas <martinez.javier@gmail.com>
Subject: Re: [PATCH 1/1] omap: serial: Add RS-485 standard support
Date: Thu, 3 Nov 2011 20:06:58 +0100 [thread overview]
Message-ID: <CAAwP0s3upt6W5Z6f=N_6ZdZnK9YtdD6SdUUvEhZgB=P8=z7Yuw@mail.gmail.com> (raw)
In-Reply-To: <1319843084-16948-1-git-send-email-martinez.javier@gmail.com>
On Sat, Oct 29, 2011 at 1:04 AM, Javier Martinez Canillas
<martinez.javier@gmail.com> wrote:
> 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 <yanok@emcraft.com> 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 <martinez.javier@gmail.com>
> ---
> 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
>
>
Hello,
Any comments for this patch?
Best regards,
--
Javier Martínez Canillas
(+34) 682 39 81 69
Barcelona, Spain
--
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prev parent reply other threads:[~2011-11-03 19:06 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-28 23:04 [PATCH 1/1] omap: serial: Add RS-485 standard support Javier Martinez Canillas
2011-11-03 19:06 ` Javier Martinez Canillas [this message]
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