mfd: wcd934x: Replace legacy gpio interface for gpiod

Considering the current transition of the GPIO subsystem, remove all
dependencies of the legacy GPIO interface (linux/gpio.h and linux
/of_gpio.h) and replace it with the descriptor-based GPIO approach.

Signed-off-by: Maíra Canal <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Link: https://lore.kernel.org/r/YXDEBCiSnXYRQPXt@fedora

Author: mairacanal

drivers/mfd/wcd934x.c

@@ -2,14 +2,13 @@
 // Copyright (c) 2019, Linaro Limited
 
 #include <linux/clk.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/wcd934x/registers.h>
 #include <linux/mfd/wcd934x/wcd934x.h>
 #include <linux/module.h>
-#include <linux/of_gpio.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/platform_device.h>
@@ -210,7 +209,8 @@ static int wcd934x_slim_probe(struct slim_device *sdev)
 	struct device *dev = &sdev->dev;
 	struct device_node *np = dev->of_node;
 	struct wcd934x_ddata *ddata;
-	int reset_gpio, ret;
+	struct gpio_desc *reset_gpio;
+	int ret;
 
 	ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
 	if (!ddata)
@@ -221,13 +221,6 @@ static int wcd934x_slim_probe(struct slim_device *sdev)
 		return dev_err_probe(ddata->dev, ddata->irq,
 				     "Failed to get IRQ\n");
 
-	reset_gpio = of_get_named_gpio(np, "reset-gpios", 0);
-	if (reset_gpio < 0) {
-		dev_err(dev, "Failed to get reset gpio: err = %d\n",
-			reset_gpio);
-		return reset_gpio;
-	}
-
 	ddata->extclk = devm_clk_get(dev, "extclk");
 	if (IS_ERR(ddata->extclk)) {
 		dev_err(dev, "Failed to get extclk");
@@ -258,9 +251,13 @@ static int wcd934x_slim_probe(struct slim_device *sdev)
 	 * SYS_RST_N shouldn't be pulled high during this time
 	 */
 	usleep_range(600, 650);
-	gpio_direction_output(reset_gpio, 0);
+	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(reset_gpio)) {
+		return dev_err_probe(dev, PTR_ERR(reset_gpio),
+				"Failed to get reset gpio: err = %ld\n", PTR_ERR(reset_gpio));
+	}
 	msleep(20);
-	gpio_set_value(reset_gpio, 1);
+	gpiod_set_value(reset_gpio, 1);
 	msleep(20);
 
 	ddata->dev = dev;