serial: omap: Convert to use GPIO descriptors

This converts the OMAP serial driver to use a GPIO descriptor
for the optional RTS signal.

Cc: Shubhrajyoti D <shubhrajyoti@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200415183927.269445-1-linus.walleij@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index f7d6b3c9ea45902dab8af5f636d985d5420df546..c71c1a2266dc64202a7237d6fb8ce6f0322bedf7 100644 (file)
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -33,8 +33,7 @@
 #include <linux/pm_wakeirq.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
-#include <linux/gpio.h>
-#include <linux/of_gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/platform_data/serial-omap.h>
 
 #define OMAP_MAX_HSUART_PORTS  10
@@ -153,7 +152,7 @@ struct uart_omap_port {
        u32                     errata;
        u32                     features;
 
-       int                     rts_gpio;
+       struct gpio_desc        *rts_gpiod;
 
        struct pm_qos_request   pm_qos_request;
        u32                     latency;
@@ -303,11 +302,11 @@ static void serial_omap_stop_tx(struct uart_port *port)
                        serial_out(up, UART_OMAP_SCR, up->scr);
                        res = (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) ?
                                1 : 0;
-                       if (gpio_get_value(up->rts_gpio) != res) {
+                       if (gpiod_get_value(up->rts_gpiod) != res) {
                                if (port->rs485.delay_rts_after_send > 0)
                                        mdelay(
                                        port->rs485.delay_rts_after_send);
-                               gpio_set_value(up->rts_gpio, res);
+                               gpiod_set_value(up->rts_gpiod, res);
                        }
                } else {
                        /* We're asked to stop, but there's still stuff in the
@@ -412,8 +411,8 @@ static void serial_omap_start_tx(struct uart_port *port)
 
                /* if rts not already enabled */
                res = (port->rs485.flags & SER_RS485_RTS_ON_SEND) ? 1 : 0;
-               if (gpio_get_value(up->rts_gpio) != res) {
-                       gpio_set_value(up->rts_gpio, res);
+               if (gpiod_get_value(up->rts_gpiod) != res) {
+                       gpiod_set_value(up->rts_gpiod, res);
                        if (port->rs485.delay_rts_before_send > 0)
                                mdelay(port->rs485.delay_rts_before_send);
                }
@@ -1414,12 +1413,12 @@ serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
         * Just as a precaution, only allow rs485
         * to be enabled if the gpio pin is valid
         */
-       if (gpio_is_valid(up->rts_gpio)) {
+       if (up->rts_gpiod) {
                /* enable / disable rts */
                val = (port->rs485.flags & SER_RS485_ENABLED) ?
                        SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND;
                val = (port->rs485.flags & val) ? 1 : 0;
-               gpio_set_value(up->rts_gpio, val);
+               gpiod_set_value(up->rts_gpiod, val);
        } else
                port->rs485.flags &= ~SER_RS485_ENABLED;
 
@@ -1596,13 +1595,15 @@ static struct omap_uart_port_info *of_get_uart_port_info(struct device *dev)
 }
 
 static int serial_omap_probe_rs485(struct uart_omap_port *up,
-                                  struct device_node *np)
+                                  struct device *dev)
 {
        struct serial_rs485 *rs485conf = &up->port.rs485;
+       struct device_node *np = dev->of_node;
+       enum gpiod_flags gflags;
        int ret;
 
        rs485conf->flags = 0;
-       up->rts_gpio = -EINVAL;
+       up->rts_gpiod = NULL;
 
        if (!np)
                return 0;
@@ -1618,19 +1619,20 @@ static int serial_omap_probe_rs485(struct uart_omap_port *up,
        }
 
        /* check for tx enable gpio */
-       up->rts_gpio = of_get_named_gpio(np, "rts-gpio", 0);
-       if (gpio_is_valid(up->rts_gpio)) {
-               ret = devm_gpio_request(up->dev, up->rts_gpio, "omap-serial");
-               if (ret < 0)
+       gflags = rs485conf->flags & SER_RS485_RTS_AFTER_SEND ?
+               GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
+       up->rts_gpiod = devm_gpiod_get_optional(dev, "rts", gflags);
+       if (IS_ERR(up->rts_gpiod)) {
+               ret = PTR_ERR(up->rts_gpiod);
+               if (ret == -EPROBE_DEFER)
                        return ret;
-               ret = rs485conf->flags & SER_RS485_RTS_AFTER_SEND ? 1 : 0;
-               ret = gpio_direction_output(up->rts_gpio, ret);
-               if (ret < 0)
-                       return ret;
-       } else if (up->rts_gpio == -EPROBE_DEFER) {
-               return -EPROBE_DEFER;
+               /*
+                * FIXME: the code historically ignored any other error than
+                * -EPROBE_DEFER and just went on without GPIO.
+                */
+               up->rts_gpiod = NULL;
        } else {
-               up->rts_gpio = -EINVAL;
+               gpiod_set_consumer_name(up->rts_gpiod, "omap-serial");
        }
 
        return 0;
@@ -1703,7 +1705,7 @@ static int serial_omap_probe(struct platform_device *pdev)
                dev_info(up->port.dev, "no wakeirq for uart%d\n",
                         up->port.line);
 
-       ret = serial_omap_probe_rs485(up, pdev->dev.of_node);
+       ret = serial_omap_probe_rs485(up, &pdev->dev);
        if (ret < 0)
                goto err_rs485;