regulator: max8952: Convert to use GPIO descriptors

This finalizes the descriptor conversion of the MAX8952 driver
by letting the VID0 and VID1 GPIOs be fetched from descriptors.

Both VID0 and VID1 must be supplied for the VID selection to work,
I add some code to preserve the semantics that if only one of
the two VID gpios is supplied, it will be initialized to low.
This might be a bit overzealous, but I want to preserve any
implicit semantics.

This is currently only used by device tree in-kernel but it is
still also possible to supply the same GPIOs using a machine
descriptor table if a board file is used.

Ideally this should be phased over to using gpio-regulator.c
that does the same thing, but it might require some refactoring
and needs testing on real hardware.

Cc: Tomasz Figa <tfiga@chromium.org>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/max8952.c

@@ -26,11 +26,9 @@
 #include <linux/platform_device.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/max8952.h>
-#include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/io.h>
 #include <linux/of.h>
-#include <linux/of_gpio.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/slab.h>
 
@@ -50,7 +48,8 @@ enum {
 struct max8952_data {
 	struct i2c_client	*client;
 	struct max8952_platform_data *pdata;
-
+	struct gpio_desc *vid0_gpiod;
+	struct gpio_desc *vid1_gpiod;
 	bool vid0;
 	bool vid1;
 };
@@ -100,16 +99,15 @@ static int max8952_set_voltage_sel(struct regulator_dev *rdev,
 {
 	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
 
-	if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
-			!gpio_is_valid(max8952->pdata->gpio_vid1)) {
+	if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) {
 		/* DVS not supported */
 		return -EPERM;
 	}
 
 	max8952->vid0 = selector & 0x1;
 	max8952->vid1 = (selector >> 1) & 0x1;
-	gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
-	gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);
+	gpiod_set_value(max8952->vid0_gpiod, max8952->vid0);
+	gpiod_set_value(max8952->vid1_gpiod, max8952->vid1);
 
 	return 0;
 }
@@ -147,9 +145,6 @@ static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
 	if (!pd)
 		return NULL;
 
-	pd->gpio_vid0 = of_get_named_gpio(np, "max8952,vid-gpios", 0);
-	pd->gpio_vid1 = of_get_named_gpio(np, "max8952,vid-gpios", 1);
-
 	if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
 		dev_warn(dev, "Default mode not specified, assuming 0\n");
 
@@ -200,7 +195,7 @@ static int max8952_pmic_probe(struct i2c_client *client,
 	struct gpio_desc *gpiod;
 	enum gpiod_flags gflags;
 
-	int ret = 0, err = 0;
+	int ret = 0;
 
 	if (client->dev.of_node)
 		pdata = max8952_parse_dt(&client->dev);
@@ -253,32 +248,31 @@ static int max8952_pmic_probe(struct i2c_client *client,
 	max8952->vid0 = pdata->default_mode & 0x1;
 	max8952->vid1 = (pdata->default_mode >> 1) & 0x1;
 
-	if (gpio_is_valid(pdata->gpio_vid0) &&
-			gpio_is_valid(pdata->gpio_vid1)) {
-		unsigned long gpio_flags;
-
-		gpio_flags = max8952->vid0 ?
-			     GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
-		if (devm_gpio_request_one(&client->dev, pdata->gpio_vid0,
-					  gpio_flags, "MAX8952 VID0"))
-			err = 1;
-
-		gpio_flags = max8952->vid1 ?
-			     GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
-		if (devm_gpio_request_one(&client->dev, pdata->gpio_vid1,
-					  gpio_flags, "MAX8952 VID1"))
-			err = 2;
-	} else
-		err = 3;
-
-	if (err) {
+	/* Fetch vid0 and vid1 GPIOs if available */
+	gflags = max8952->vid0 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
+	max8952->vid0_gpiod = devm_gpiod_get_index_optional(&client->dev,
+							    "max8952,vid",
+							    0, gflags);
+	if (IS_ERR(max8952->vid0_gpiod))
+		return PTR_ERR(max8952->vid0_gpiod);
+	gflags = max8952->vid1 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
+	max8952->vid1_gpiod = devm_gpiod_get_index_optional(&client->dev,
+							    "max8952,vid",
+							    1, gflags);
+	if (IS_ERR(max8952->vid1_gpiod))
+		return PTR_ERR(max8952->vid1_gpiod);
+
+	/* If either VID GPIO is missing just disable this */
+	if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) {
 		dev_warn(&client->dev, "VID0/1 gpio invalid: "
 			 "DVS not available.\n");
 		max8952->vid0 = 0;
 		max8952->vid1 = 0;
-		/* Mark invalid */
-		pdata->gpio_vid0 = -1;
-		pdata->gpio_vid1 = -1;
+		/* Make sure if we have any descriptors they get set to low */
+		if (max8952->vid0_gpiod)
+			gpiod_set_value(max8952->vid0_gpiod, 0);
+		if (max8952->vid1_gpiod)
+			gpiod_set_value(max8952->vid1_gpiod, 0);
 
 		/* Disable Pulldown of EN only */
 		max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);

include/linux/regulator/max8952.h

@@ -118,9 +118,6 @@ enum {
 #define MAX8952_NUM_DVS_MODE	4
 
 struct max8952_platform_data {
-	int gpio_vid0;
-	int gpio_vid1;
-
 	u32 default_mode;
 	u32 dvs_mode[MAX8952_NUM_DVS_MODE]; /* MAX8952_DVS_MODEx_XXXXmV */