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serial: imx: implement handshaking using gpios with the mctrl_gpio helper

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Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Uwe Kleine-König 2015-12-13 11:30:03 +01:00 committed by Greg Kroah-Hartman
parent 4f71a2e0a2
commit 58362d5be3
2 changed files with 70 additions and 20 deletions
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1
drivers/tty/serial/Kconfig
View file

@ -576,6 +576,7 @@ config SERIAL_IMX
depends on ARCH_MXC || COMPILE_TEST
select SERIAL_CORE
select RATIONAL
select SERIAL_MCTRL_GPIO if GPIOLIB
help
If you have a machine based on a Motorola IMX CPU you
can enable its onboard serial port by enabling this option.

89
drivers/tty/serial/imx.c
View file

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