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authorLinus Walleij <linus.walleij@linaro.org>2013-11-07 10:25:55 +0100
committerUwe Kleine-König <u.kleine-koenig@pengutronix.de>2013-12-20 11:41:30 +0100
commit354e57f3a0a26120af3bcd6c92c355ad00a057c1 (patch)
tree6935c516167f34df47ebce43c579bbc8ce53f8d4 /drivers/tty
parent6a79799d5654bb7800614e8b7a009252be7ff90e (diff)
downloadop-kernel-dev-354e57f3a0a26120af3bcd6c92c355ad00a057c1.zip
op-kernel-dev-354e57f3a0a26120af3bcd6c92c355ad00a057c1.tar.gz
ARM/serial: at91: switch atmel serial to use gpiolib
This passes the errata fix using a GPIO to control the RTS pin on one of the AT91 chips to use gpiolib instead of the AT91-specific interfaces. Also remove the reliance on compile-time #defines and the cpu_* check and rely on the platform passing down the proper GPIO pin through platform data. This is a prerequisite for getting rid of the local GPIO implementation in the AT91 platform and move toward multiplatform. The patch also adds device tree support for getting the RTS GPIO pin from the device tree on DT boot paths. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/atmel_serial.c49
1 files changed, 31 insertions, 18 deletions
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index c7d99af..40d6c9b 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -35,21 +35,18 @@
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/of_gpio.h>
#include <linux/dma-mapping.h>
#include <linux/atmel_pdc.h>
#include <linux/atmel_serial.h>
#include <linux/uaccess.h>
#include <linux/platform_data/atmel.h>
#include <linux/timer.h>
+#include <linux/gpio.h>
#include <asm/io.h>
#include <asm/ioctls.h>
-#ifdef CONFIG_ARM
-#include <mach/cpu.h>
-#include <asm/gpio.h>
-#endif
-
#define PDC_BUFFER_SIZE 512
/* Revisit: We should calculate this based on the actual port settings */
#define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */
@@ -168,6 +165,7 @@ struct atmel_uart_port {
struct circ_buf rx_ring;
struct serial_rs485 rs485; /* rs485 settings */
+ int rts_gpio; /* optional RTS GPIO */
unsigned int tx_done_mask;
bool is_usart; /* usart or uart */
struct timer_list uart_timer; /* uart timer */
@@ -301,20 +299,16 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
unsigned int mode;
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
-#ifdef CONFIG_ARCH_AT91RM9200
- if (cpu_is_at91rm9200()) {
- /*
- * AT91RM9200 Errata #39: RTS0 is not internally connected
- * to PA21. We need to drive the pin manually.
- */
- if (port->mapbase == AT91RM9200_BASE_US0) {
- if (mctrl & TIOCM_RTS)
- at91_set_gpio_value(AT91_PIN_PA21, 0);
- else
- at91_set_gpio_value(AT91_PIN_PA21, 1);
- }
+ /*
+ * AT91RM9200 Errata #39: RTS0 is not internally connected
+ * to PA21. We need to drive the pin as a GPIO.
+ */
+ if (gpio_is_valid(atmel_port->rts_gpio)) {
+ if (mctrl & TIOCM_RTS)
+ gpio_set_value(atmel_port->rts_gpio, 0);
+ else
+ gpio_set_value(atmel_port->rts_gpio, 1);
}
-#endif
if (mctrl & TIOCM_RTS)
control |= ATMEL_US_RTSEN;
@@ -2379,6 +2373,25 @@ static int atmel_serial_probe(struct platform_device *pdev)
port = &atmel_ports[ret];
port->backup_imr = 0;
port->uart.line = ret;
+ port->rts_gpio = -EINVAL; /* Invalid, zero could be valid */
+ if (pdata)
+ port->rts_gpio = pdata->rts_gpio;
+ else if (np)
+ port->rts_gpio = of_get_named_gpio(np, "rts-gpios", 0);
+
+ if (gpio_is_valid(port->rts_gpio)) {
+ ret = devm_gpio_request(&pdev->dev, port->rts_gpio, "RTS");
+ if (ret) {
+ dev_err(&pdev->dev, "error requesting RTS GPIO\n");
+ goto err;
+ }
+ /* Default to 1 as RTS is active low */
+ ret = gpio_direction_output(port->rts_gpio, 1);
+ if (ret) {
+ dev_err(&pdev->dev, "error setting up RTS GPIO\n");
+ goto err;
+ }
+ }
ret = atmel_init_port(port, pdev);
if (ret)
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