regulator: gpio: Convert to use descriptors

This converts the GPIO regulator driver to use decriptors only.

We have to let go of the array gpio handling: the fetched descriptors
are handled individually anyway, and the array retrieveal function
does not make it possible to retrieve each GPIO descriptor with
unique flags. Instead get them one by one.

We request the "enable" GPIO separately as before, and make sure
that this line is requested as nonexclusive since enable lines can
be shared and the regulator core expects this.

Most users of the GPIO regulator are using device tree.

There are two boards in the kernel using the gpio regulator from a
non-devicetree path: PXA hx4700 and magician. Make sure to switch
these over to use descriptors as well.

Cc: Philipp Zabel <p.zabel@pengutronix.de> # Magician
Cc: Petr Cvek <petr.cvek@tul.cz> # Magician
Cc: Robert Jarzmik <robert.jarzmik@free.fr> # PXA
Cc: Paul Parsons <lost.distance@yahoo.com> # hx4700
Cc: Kevin Hilman <khilman@baylibre.com> # Meson
Cc: Neil Armstrong <narmstrong@baylibre.com> # Meson
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

arch/arm/mach-pxa/hx4700.c

@@ -19,6 +19,7 @@
 #include <linux/platform_device.h>
 #include <linux/delay.h>
 #include <linux/fb.h>
+#include <linux/gpio/machine.h>
 #include <linux/gpio.h>
 #include <linux/gpio_keys.h>
 #include <linux/input.h>
@@ -702,9 +703,7 @@ static struct regulator_init_data bq24022_init_data = {
 	.consumer_supplies      = bq24022_consumers,
 };
 
-static struct gpio bq24022_gpios[] = {
-	{ GPIO96_HX4700_BQ24022_ISET2, GPIOF_OUT_INIT_LOW, "bq24022_iset2" },
-};
+static enum gpiod_flags bq24022_gpiod_gflags[] = { GPIOD_OUT_LOW };
 
 static struct gpio_regulator_state bq24022_states[] = {
 	{ .value = 100000, .gpios = (0 << 0) },
@@ -714,12 +713,10 @@ static struct gpio_regulator_state bq24022_states[] = {
 static struct gpio_regulator_config bq24022_info = {
 	.supply_name = "bq24022",
 
-	.enable_gpio = GPIO72_HX4700_BQ24022_nCHARGE_EN,
-	.enable_high = 0,
 	.enabled_at_boot = 0,
 
-	.gpios = bq24022_gpios,
-	.nr_gpios = ARRAY_SIZE(bq24022_gpios),
+	.gflags = bq24022_gpiod_gflags,
+	.ngpios = ARRAY_SIZE(bq24022_gpiod_gflags),
 
 	.states = bq24022_states,
 	.nr_states = ARRAY_SIZE(bq24022_states),
@@ -736,6 +733,17 @@ static struct platform_device bq24022 = {
 	},
 };
 
+static struct gpiod_lookup_table bq24022_gpiod_table = {
+	.dev_id = "gpio-regulator",
+	.table = {
+		GPIO_LOOKUP("gpio-pxa", GPIO96_HX4700_BQ24022_ISET2,
+			    NULL, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP("gpio-pxa", GPIO72_HX4700_BQ24022_nCHARGE_EN,
+			    "enable", GPIO_ACTIVE_LOW),
+		{ },
+	},
+};
+
 /*
  * StrataFlash
  */
@@ -878,6 +886,7 @@ static void __init hx4700_init(void)
 	pxa_set_btuart_info(NULL);
 	pxa_set_stuart_info(NULL);
 
+	gpiod_add_lookup_table(&bq24022_gpiod_table);
 	platform_add_devices(devices, ARRAY_SIZE(devices));
 	pwm_add_table(hx4700_pwm_lookup, ARRAY_SIZE(hx4700_pwm_lookup));
 

arch/arm/mach-pxa/magician.c

@@ -645,9 +645,8 @@ static struct regulator_init_data bq24022_init_data = {
 	.consumer_supplies	= bq24022_consumers,
 };
 
-static struct gpio bq24022_gpios[] = {
-	{ EGPIO_MAGICIAN_BQ24022_ISET2, GPIOF_OUT_INIT_LOW, "bq24022_iset2" },
-};
+
+static enum gpiod_flags bq24022_gpiod_gflags[] = { GPIOD_OUT_LOW };
 
 static struct gpio_regulator_state bq24022_states[] = {
 	{ .value = 100000, .gpios = (0 << 0) },
@@ -657,12 +656,10 @@ static struct gpio_regulator_state bq24022_states[] = {
 static struct gpio_regulator_config bq24022_info = {
 	.supply_name		= "bq24022",
 
-	.enable_gpio		= GPIO30_MAGICIAN_BQ24022_nCHARGE_EN,
-	.enable_high		= 0,
 	.enabled_at_boot	= 1,
 
-	.gpios			= bq24022_gpios,
-	.nr_gpios		= ARRAY_SIZE(bq24022_gpios),
+	.gflags = bq24022_gpiod_gflags,
+	.ngpios = ARRAY_SIZE(bq24022_gpiod_gflags),
 
 	.states			= bq24022_states,
 	.nr_states		= ARRAY_SIZE(bq24022_states),
@@ -679,6 +676,17 @@ static struct platform_device bq24022 = {
 	},
 };
 
+static struct gpiod_lookup_table bq24022_gpiod_table = {
+	.dev_id = "gpio-regulator",
+	.table = {
+		GPIO_LOOKUP("gpio-pxa", EGPIO_MAGICIAN_BQ24022_ISET2,
+			    NULL, GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP("gpio-pxa", GPIO30_MAGICIAN_BQ24022_nCHARGE_EN,
+			    "enable", GPIO_ACTIVE_LOW),
+		{ },
+	},
+};
+
 /*
  * fixed regulator for ads7846
  */
@@ -1027,6 +1035,7 @@ static void __init magician_init(void)
 	regulator_register_always_on(0, "power", pwm_backlight_supply,
 		ARRAY_SIZE(pwm_backlight_supply), 5000000);
 
+	gpiod_add_lookup_table(&bq24022_gpiod_table);
 	platform_add_devices(ARRAY_AND_SIZE(devices));
 }
 

drivers/regulator/gpio-regulator.c

@@ -30,16 +30,15 @@
 #include <linux/regulator/machine.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/regulator/gpio-regulator.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/slab.h>
 #include <linux/of.h>
-#include <linux/of_gpio.h>
 
 struct gpio_regulator_data {
 	struct regulator_desc desc;
 	struct regulator_dev *dev;
 
-	struct gpio *gpios;
+	struct gpio_desc **gpiods;
 	int nr_gpios;
 
 	struct gpio_regulator_state *states;
@@ -82,7 +81,7 @@ static int gpio_regulator_set_voltage(struct regulator_dev *dev,
 
 	for (ptr = 0; ptr < data->nr_gpios; ptr++) {
 		state = (target & (1 << ptr)) >> ptr;
-		gpio_set_value_cansleep(data->gpios[ptr].gpio, state);
+		gpiod_set_value_cansleep(data->gpiods[ptr], state);
 	}
 	data->state = target;
 
@@ -119,7 +118,7 @@ static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
 
 	for (ptr = 0; ptr < data->nr_gpios; ptr++) {
 		state = (target & (1 << ptr)) >> ptr;
-		gpio_set_value_cansleep(data->gpios[ptr].gpio, state);
+		gpiod_set_value_cansleep(data->gpiods[ptr], state);
 	}
 	data->state = target;
 
@@ -138,7 +137,8 @@ of_get_gpio_regulator_config(struct device *dev, struct device_node *np,
 {
 	struct gpio_regulator_config *config;
 	const char *regtype;
-	int proplen, gpio, i;
+	int proplen, i;
+	int ngpios;
 	int ret;
 
 	config = devm_kzalloc(dev,
@@ -153,59 +153,36 @@ of_get_gpio_regulator_config(struct device *dev, struct device_node *np,
 
 	config->supply_name = config->init_data->constraints.name;
 
-	if (of_property_read_bool(np, "enable-active-high"))
-		config->enable_high = true;
-
 	if (of_property_read_bool(np, "enable-at-boot"))
 		config->enabled_at_boot = true;
 
 	of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
 
-	config->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
-	if (config->enable_gpio < 0 && config->enable_gpio != -ENOENT)
-		return ERR_PTR(config->enable_gpio);
-
-	/* Fetch GPIOs. - optional property*/
-	ret = of_gpio_count(np);
-	if ((ret < 0) && (ret != -ENOENT))
-		return ERR_PTR(ret);
-
-	if (ret > 0) {
-		config->nr_gpios = ret;
-		config->gpios = devm_kcalloc(dev,
-					config->nr_gpios, sizeof(struct gpio),
+	/* Fetch GPIO init levels */
+	ngpios = gpiod_count(dev, NULL);
+	if (ngpios > 0) {
+		config->gflags = devm_kzalloc(dev,
+					      sizeof(enum gpiod_flags)
+					      * ngpios,
 					      GFP_KERNEL);
-		if (!config->gpios)
+		if (!config->gflags)
 			return ERR_PTR(-ENOMEM);
 
-		proplen = of_property_count_u32_elems(np, "gpios-states");
-		/* optional property */
-		if (proplen < 0)
-			proplen = 0;
+		for (i = 0; i < ngpios; i++) {
+			u32 val;
 
-		if (proplen > 0 && proplen != config->nr_gpios) {
-			dev_warn(dev, "gpios <-> gpios-states mismatch\n");
-			proplen = 0;
-		}
+			ret = of_property_read_u32_index(np, "gpios-states", i,
+							 &val);
 
-		for (i = 0; i < config->nr_gpios; i++) {
-			gpio = of_get_named_gpio(np, "gpios", i);
-			if (gpio < 0) {
-				if (gpio != -ENOENT)
-					return ERR_PTR(gpio);
-				break;
-			}
-			config->gpios[i].gpio = gpio;
-			config->gpios[i].label = config->supply_name;
-			if (proplen > 0) {
-				of_property_read_u32_index(np, "gpios-states",
-							   i, &ret);
+			/* Default to high per specification */
 			if (ret)
-					config->gpios[i].flags =
-							   GPIOF_OUT_INIT_HIGH;
-			}
+				config->gflags[i] = GPIOD_OUT_HIGH;
+			else
+				config->gflags[i] =
+					val ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
 		}
 	}
+	config->ngpios = ngpios;
 
 	/* Fetch states. */
 	proplen = of_property_count_u32_elems(np, "states");
@@ -255,7 +232,8 @@ static int gpio_regulator_probe(struct platform_device *pdev)
 	struct device_node *np = pdev->dev.of_node;
 	struct gpio_regulator_data *drvdata;
 	struct regulator_config cfg = { };
-	int ptr, ret, state;
+	enum gpiod_flags gflags;
+	int ptr, ret, state, i;
 
 	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
 			       GFP_KERNEL);
@@ -275,26 +253,21 @@ static int gpio_regulator_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
-	if (config->nr_gpios != 0) {
-		drvdata->gpios = kmemdup(config->gpios,
-					 config->nr_gpios * sizeof(struct gpio),
+	drvdata->gpiods = devm_kzalloc(&pdev->dev, sizeof(struct gpio_desc *),
 				       GFP_KERNEL);
-		if (drvdata->gpios == NULL) {
-			dev_err(&pdev->dev, "Failed to allocate gpio data\n");
-			ret = -ENOMEM;
-			goto err_name;
-		}
-
-		drvdata->nr_gpios = config->nr_gpios;
-		ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
-		if (ret) {
-			if (ret != -EPROBE_DEFER)
-				dev_err(&pdev->dev,
-					"Could not obtain regulator setting GPIOs: %d\n",
-					ret);
-			goto err_memgpio;
-		}
+	if (!drvdata->gpiods)
+		return -ENOMEM;
+	for (i = 0; i < config->ngpios; i++) {
+		drvdata->gpiods[i] = devm_gpiod_get_index(&pdev->dev,
+							  NULL,
+							  i,
+							  config->gflags[i]);
+		if (IS_ERR(drvdata->gpiods[i]))
+			return PTR_ERR(drvdata->gpiods[i]);
+		/* This is good to know */
+		gpiod_set_consumer_name(drvdata->gpiods[i], drvdata->desc.name);
 	}
+	drvdata->nr_gpios = config->ngpios;
 
 	drvdata->states = kmemdup(config->states,
 				  config->nr_states *
@@ -303,7 +276,7 @@ static int gpio_regulator_probe(struct platform_device *pdev)
 	if (drvdata->states == NULL) {
 		dev_err(&pdev->dev, "Failed to allocate state data\n");
 		ret = -ENOMEM;
-		goto err_stategpio;
+		goto err_name;
 	}
 	drvdata->nr_states = config->nr_states;
 
@@ -330,7 +303,7 @@ static int gpio_regulator_probe(struct platform_device *pdev)
 	/* build initial state from gpio init data. */
 	state = 0;
 	for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
-		if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
+		if (config->gflags[ptr] == GPIOD_OUT_HIGH)
 			state |= (1 << ptr);
 	}
 	drvdata->state = state;
@@ -340,21 +313,19 @@ static int gpio_regulator_probe(struct platform_device *pdev)
 	cfg.driver_data = drvdata;
 	cfg.of_node = np;
 
-	if (gpio_is_valid(config->enable_gpio)) {
-		cfg.ena_gpio = config->enable_gpio;
-		cfg.ena_gpio_initialized = true;
-	}
-	cfg.ena_gpio_invert = !config->enable_high;
-	if (config->enabled_at_boot) {
-		if (config->enable_high)
-			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
-		else
-			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
-	} else {
-		if (config->enable_high)
-			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
+	/*
+	 * The signal will be inverted by the GPIO core if flagged so in the
+	 * decriptor.
+	 */
+	if (config->enabled_at_boot)
+		gflags = GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE;
 	else
-			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
+		gflags = GPIOD_OUT_LOW | GPIOD_FLAGS_BIT_NONEXCLUSIVE;
+
+	cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, "enable", gflags);
+	if (IS_ERR(cfg.ena_gpiod)) {
+		ret = PTR_ERR(cfg.ena_gpiod);
+		goto err_memstate;
 	}
 
 	drvdata->dev = regulator_register(&drvdata->desc, &cfg);
@@ -370,10 +341,6 @@ static int gpio_regulator_probe(struct platform_device *pdev)
 
 err_memstate:
 	kfree(drvdata->states);
-err_stategpio:
-	gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
-err_memgpio:
-	kfree(drvdata->gpios);
 err_name:
 	kfree(drvdata->desc.name);
 	return ret;
@@ -384,12 +351,7 @@ static int gpio_regulator_remove(struct platform_device *pdev)
 	struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
 
 	regulator_unregister(drvdata->dev);
-
-	gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
-
 	kfree(drvdata->states);
-	kfree(drvdata->gpios);
-
 	kfree(drvdata->desc.name);
 
 	return 0;

include/linux/regulator/gpio-regulator.h

@@ -21,6 +21,8 @@
 #ifndef __REGULATOR_GPIO_H
 #define __REGULATOR_GPIO_H
 
+#include <linux/gpio/consumer.h>
+
 struct regulator_init_data;
 
 enum regulator_type;
@@ -53,9 +55,9 @@ struct gpio_regulator_state {
  *			This is used to keep the regulator at
  *			the default state
  * @startup_delay:	Start-up time in microseconds
- * @gpios:		Array containing the gpios needed to control
- *			the setting of the regulator
- * @nr_gpios:		Number of gpios
+ * @gflags:		Array of GPIO configuration flags for initial
+ *			states
+ * @ngpios:		Number of GPIOs and configurations available
  * @states:		Array of gpio_regulator_state entries describing
  *			the gpio state for specific voltages
  * @nr_states:		Number of states available
@@ -74,8 +76,8 @@ struct gpio_regulator_config {
 	unsigned enabled_at_boot:1;
 	unsigned startup_delay;
 
-	struct gpio *gpios;
-	int nr_gpios;
+	enum gpiod_flags *gflags;
+	int ngpios;
 
 	struct gpio_regulator_state *states;
 	int nr_states;