serial: imx: implement handshaking using gpios with the mctrl_gpio helper
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>hifive-unleashed-5.1
Uwe Kleine-König
Greg Kroah-Hartman
parent
4f71a2e0a2
commit
58362d5be3
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@ -576,6 +576,7 @@ config SERIAL_IMX
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depends on ARCH_MXC || COMPILE_TEST
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select SERIAL_CORE
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select RATIONAL
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select SERIAL_MCTRL_GPIO if GPIOLIB
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help
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If you have a machine based on a Motorola IMX CPU you
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can enable its onboard serial port by enabling this option.
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@ -44,6 +44,8 @@
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#include <linux/platform_data/serial-imx.h>
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#include <linux/platform_data/dma-imx.h>
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#include "serial_mctrl_gpio.h"
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/* Register definitions */
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#define URXD0 0x0 /* Receiver Register */
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#define URTX0 0x40 /* Transmitter Register */
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@ -209,6 +211,8 @@ struct imx_port {
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struct clk *clk_per;
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const struct imx_uart_data *devdata;
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struct mctrl_gpios *gpios;
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/* DMA fields */
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unsigned int dma_is_inited:1;
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unsigned int dma_is_enabled:1;
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@ -311,6 +315,26 @@ static void imx_port_ucrs_restore(struct uart_port *port,
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}
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#endif
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static void imx_port_rts_active(struct imx_port *sport, unsigned long *ucr2)
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{
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*ucr2 &= ~UCR2_CTSC;
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*ucr2 |= UCR2_CTS;
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mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS);
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}
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static void imx_port_rts_inactive(struct imx_port *sport, unsigned long *ucr2)
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{
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*ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
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mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS);
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}
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static void imx_port_rts_auto(struct imx_port *sport, unsigned long *ucr2)
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{
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*ucr2 |= UCR2_CTSC;
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}
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/*
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* interrupts disabled on entry
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*/
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@ -334,9 +358,9 @@ static void imx_stop_tx(struct uart_port *port)
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readl(port->membase + USR2) & USR2_TXDC) {
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temp = readl(port->membase + UCR2);
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if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
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temp &= ~UCR2_CTS;
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imx_port_rts_inactive(sport, &temp);
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else
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temp |= UCR2_CTS;
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imx_port_rts_active(sport, &temp);
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writel(temp, port->membase + UCR2);
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temp = readl(port->membase + UCR4);
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@ -378,6 +402,8 @@ static void imx_enable_ms(struct uart_port *port)
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struct imx_port *sport = (struct imx_port *)port;
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mod_timer(&sport->timer, jiffies);
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mctrl_gpio_enable_ms(sport->gpios);
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}
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static void imx_dma_tx(struct imx_port *sport);
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@ -537,14 +563,14 @@ static void imx_start_tx(struct uart_port *port)
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unsigned long temp;
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if (port->rs485.flags & SER_RS485_ENABLED) {
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/* enable transmitter and shifter empty irq */
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temp = readl(port->membase + UCR2);
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if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
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temp &= ~UCR2_CTS;
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imx_port_rts_inactive(sport, &temp);
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else
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temp |= UCR2_CTS;
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imx_port_rts_active(sport, &temp);
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writel(temp, port->membase + UCR2);
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/* enable transmitter and shifter empty irq */
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temp = readl(port->membase + UCR4);
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temp |= UCR4_TCEN;
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writel(temp, port->membase + UCR4);
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@ -759,9 +785,8 @@ static unsigned int imx_tx_empty(struct uart_port *port)
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/*
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* We have a modem side uart, so the meanings of RTS and CTS are inverted.
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*/
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static unsigned int imx_get_mctrl(struct uart_port *port)
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static unsigned int imx_get_hwmctrl(struct imx_port *sport)
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{
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struct imx_port *sport = (struct imx_port *)port;
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unsigned int tmp = TIOCM_DSR;
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unsigned usr1 = readl(sport->port.membase + USR1);
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@ -779,6 +804,16 @@ static unsigned int imx_get_mctrl(struct uart_port *port)
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return tmp;
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}
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static unsigned int imx_get_mctrl(struct uart_port *port)
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{
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struct imx_port *sport = (struct imx_port *)port;
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unsigned int ret = imx_get_hwmctrl(sport);
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mctrl_gpio_get(sport->gpios, &ret);
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return ret;
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}
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static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
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{
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struct imx_port *sport = (struct imx_port *)port;
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@ -801,6 +836,8 @@ static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
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if (mctrl & TIOCM_LOOP)
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temp |= UTS_LOOP;
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writel(temp, sport->port.membase + uts_reg(sport));
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mctrl_gpio_set(sport->gpios, mctrl);
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}
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/*
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@ -830,7 +867,7 @@ static void imx_mctrl_check(struct imx_port *sport)
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{
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unsigned int status, changed;
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status = imx_get_mctrl(&sport->port);
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status = imx_get_hwmctrl(sport);
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changed = status ^ sport->old_status;
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if (changed == 0)
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@ -1218,6 +1255,8 @@ static void imx_shutdown(struct uart_port *port)
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imx_uart_dma_exit(sport);
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}
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mctrl_gpio_disable_ms(sport->gpios);
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spin_lock_irqsave(&sport->port.lock, flags);
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temp = readl(sport->port.membase + UCR2);
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temp &= ~(UCR2_TXEN);
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@ -1295,9 +1334,10 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios,
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{
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struct imx_port *sport = (struct imx_port *)port;
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unsigned long flags;
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unsigned int ucr2, old_ucr1, old_ucr2, baud, quot;
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unsigned long ucr2, old_ucr1, old_ucr2;
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unsigned int baud, quot;
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unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
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unsigned int div, ufcr;
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unsigned long div, ufcr;
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unsigned long num, denom;
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uint64_t tdiv64;
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@ -1326,19 +1366,25 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios,
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* it under manual control and keep transmitter
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* disabled.
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*/
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if (!(port->rs485.flags &
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SER_RS485_RTS_AFTER_SEND))
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ucr2 |= UCR2_CTS;
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if (port->rs485.flags &
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SER_RS485_RTS_AFTER_SEND)
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imx_port_rts_inactive(sport, &ucr2);
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else
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imx_port_rts_active(sport, &ucr2);
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} else {
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ucr2 |= UCR2_CTSC;
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imx_port_rts_auto(sport, &ucr2);
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}
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} else {
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termios->c_cflag &= ~CRTSCTS;
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}
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} else if (port->rs485.flags & SER_RS485_ENABLED)
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} else if (port->rs485.flags & SER_RS485_ENABLED) {
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/* disable transmitter */
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if (!(port->rs485.flags & SER_RS485_RTS_AFTER_SEND))
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ucr2 |= UCR2_CTS;
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if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
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imx_port_rts_inactive(sport, &ucr2);
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else
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imx_port_rts_active(sport, &ucr2);
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}
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if (termios->c_cflag & CSTOPB)
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ucr2 |= UCR2_STPB;
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@ -1579,11 +1625,10 @@ static int imx_rs485_config(struct uart_port *port,
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/* disable transmitter */
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temp = readl(sport->port.membase + UCR2);
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temp &= ~UCR2_CTSC;
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if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
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temp &= ~UCR2_CTS;
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imx_port_rts_inactive(sport, &temp);
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else
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temp |= UCR2_CTS;
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imx_port_rts_active(sport, &temp);
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writel(temp, sport->port.membase + UCR2);
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}
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@ -1956,6 +2001,10 @@ static int serial_imx_probe(struct platform_device *pdev)
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sport->timer.function = imx_timeout;
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sport->timer.data = (unsigned long)sport;
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sport->gpios = mctrl_gpio_init(&sport->port, 0);
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if (IS_ERR(sport->gpios))
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return PTR_ERR(sport->gpios);
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sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
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if (IS_ERR(sport->clk_ipg)) {
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ret = PTR_ERR(sport->clk_ipg);
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