1 files changed, 423 insertions, 0 deletions

diff --git a/drivers/regulator/gpio-regulator.c b/drivers/regulator/gpio-regulator.c
new file mode 100644
index 000000000..464018de7
--- /dev/null
+++ b/drivers/regulator/gpio-regulator.c
@@ -0,0 +1,423 @@
+/*
+ * gpio-regulator.c
+ *
+ * Copyright 2011 Heiko Stuebner <heiko@sntech.de>
+ *
+ * based on fixed.c
+ *
+ * Copyright 2008 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ * Copyright (c) 2009 Nokia Corporation
+ * Roger Quadros <ext-roger.quadros@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This is useful for systems with mixed controllable and
+ * non-controllable regulators, as well as for allowing testing on
+ * systems with no controllable regulators.
+ */
+
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/regulator/gpio-regulator.h>
+#include <linux/gpio.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;
+	int nr_gpios;
+
+	struct gpio_regulator_state *states;
+	int nr_states;
+
+	int state;
+};
+
+static int gpio_regulator_get_value(struct regulator_dev *dev)
+{
+	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
+	int ptr;
+
+	for (ptr = 0; ptr < data->nr_states; ptr++)
+		if (data->states[ptr].gpios == data->state)
+			return data->states[ptr].value;
+
+	return -EINVAL;
+}
+
+static int gpio_regulator_set_voltage(struct regulator_dev *dev,
+					int min_uV, int max_uV,
+					unsigned *selector)
+{
+	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
+	int ptr, target = 0, state, best_val = INT_MAX;
+
+	for (ptr = 0; ptr < data->nr_states; ptr++)
+		if (data->states[ptr].value < best_val &&
+		    data->states[ptr].value >= min_uV &&
+		    data->states[ptr].value <= max_uV) {
+			target = data->states[ptr].gpios;
+			best_val = data->states[ptr].value;
+			if (selector)
+				*selector = ptr;
+		}
+
+	if (best_val == INT_MAX)
+		return -EINVAL;
+
+	for (ptr = 0; ptr < data->nr_gpios; ptr++) {
+		state = (target & (1 << ptr)) >> ptr;
+		gpio_set_value_cansleep(data->gpios[ptr].gpio, state);
+	}
+	data->state = target;
+
+	return 0;
+}
+
+static int gpio_regulator_list_voltage(struct regulator_dev *dev,
+				      unsigned selector)
+{
+	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
+
+	if (selector >= data->nr_states)
+		return -EINVAL;
+
+	return data->states[selector].value;
+}
+
+static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
+					int min_uA, int max_uA)
+{
+	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
+	int ptr, target = 0, state, best_val = 0;
+
+	for (ptr = 0; ptr < data->nr_states; ptr++)
+		if (data->states[ptr].value > best_val &&
+		    data->states[ptr].value >= min_uA &&
+		    data->states[ptr].value <= max_uA) {
+			target = data->states[ptr].gpios;
+			best_val = data->states[ptr].value;
+		}
+
+	if (best_val == 0)
+		return -EINVAL;
+
+	for (ptr = 0; ptr < data->nr_gpios; ptr++) {
+		state = (target & (1 << ptr)) >> ptr;
+		gpio_set_value_cansleep(data->gpios[ptr].gpio, state);
+	}
+	data->state = target;
+
+	return 0;
+}
+
+static struct regulator_ops gpio_regulator_voltage_ops = {
+	.get_voltage = gpio_regulator_get_value,
+	.set_voltage = gpio_regulator_set_voltage,
+	.list_voltage = gpio_regulator_list_voltage,
+};
+
+static struct gpio_regulator_config *
+of_get_gpio_regulator_config(struct device *dev, struct device_node *np,
+			     const struct regulator_desc *desc)
+{
+	struct gpio_regulator_config *config;
+	const char *regtype;
+	int proplen, gpio, i;
+	int ret;
+
+	config = devm_kzalloc(dev,
+			sizeof(struct gpio_regulator_config),
+			GFP_KERNEL);
+	if (!config)
+		return ERR_PTR(-ENOMEM);
+
+	config->init_data = of_get_regulator_init_data(dev, np, desc);
+	if (!config->init_data)
+		return ERR_PTR(-EINVAL);
+
+	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);
+
+	/* 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_kzalloc(dev,
+					sizeof(struct gpio) * config->nr_gpios,
+					GFP_KERNEL);
+		if (!config->gpios)
+			return ERR_PTR(-ENOMEM);
+
+		proplen = of_property_count_u32_elems(np, "gpios-states");
+		/* optional property */
+		if (proplen < 0)
+			proplen = 0;
+
+		if (proplen > 0 && proplen != config->nr_gpios) {
+			dev_warn(dev, "gpios <-> gpios-states mismatch\n");
+			proplen = 0;
+		}
+
+		for (i = 0; i < config->nr_gpios; i++) {
+			gpio = of_get_named_gpio(np, "gpios", i);
+			if (gpio < 0)
+				break;
+			config->gpios[i].gpio = gpio;
+			if (proplen > 0) {
+				of_property_read_u32_index(np, "gpios-states",
+							   i, &ret);
+				if (ret)
+					config->gpios[i].flags =
+							   GPIOF_OUT_INIT_HIGH;
+			}
+		}
+	}
+
+	/* Fetch states. */
+	proplen = of_property_count_u32_elems(np, "states");
+	if (proplen < 0) {
+		dev_err(dev, "No 'states' property found\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	config->states = devm_kzalloc(dev,
+				sizeof(struct gpio_regulator_state)
+				* (proplen / 2),
+				GFP_KERNEL);
+	if (!config->states)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < proplen / 2; i++) {
+		of_property_read_u32_index(np, "states", i * 2,
+					   &config->states[i].value);
+		of_property_read_u32_index(np, "states", i * 2 + 1,
+					   &config->states[i].gpios);
+	}
+	config->nr_states = i;
+
+	config->type = REGULATOR_VOLTAGE;
+	ret = of_property_read_string(np, "regulator-type", &regtype);
+	if (ret >= 0) {
+		if (!strncmp("voltage", regtype, 7))
+			config->type = REGULATOR_VOLTAGE;
+		else if (!strncmp("current", regtype, 7))
+			config->type = REGULATOR_CURRENT;
+		else
+			dev_warn(dev, "Unknown regulator-type '%s'\n",
+				 regtype);
+	}
+
+	return config;
+}
+
+static struct regulator_ops gpio_regulator_current_ops = {
+	.get_current_limit = gpio_regulator_get_value,
+	.set_current_limit = gpio_regulator_set_current_limit,
+};
+
+static int gpio_regulator_probe(struct platform_device *pdev)
+{
+	struct gpio_regulator_config *config = dev_get_platdata(&pdev->dev);
+	struct device_node *np = pdev->dev.of_node;
+	struct gpio_regulator_data *drvdata;
+	struct regulator_config cfg = { };
+	int ptr, ret, state;
+
+	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
+			       GFP_KERNEL);
+	if (drvdata == NULL)
+		return -ENOMEM;
+
+	if (np) {
+		config = of_get_gpio_regulator_config(&pdev->dev, np,
+						      &drvdata->desc);
+		if (IS_ERR(config))
+			return PTR_ERR(config);
+	}
+
+	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
+	if (drvdata->desc.name == NULL) {
+		dev_err(&pdev->dev, "Failed to allocate supply name\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	if (config->nr_gpios != 0) {
+		drvdata->gpios = kmemdup(config->gpios,
+					 config->nr_gpios * sizeof(struct gpio),
+					 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) {
+			dev_err(&pdev->dev,
+			"Could not obtain regulator setting GPIOs: %d\n", ret);
+			goto err_memstate;
+		}
+	}
+
+	drvdata->states = kmemdup(config->states,
+				  config->nr_states *
+					 sizeof(struct gpio_regulator_state),
+				  GFP_KERNEL);
+	if (drvdata->states == NULL) {
+		dev_err(&pdev->dev, "Failed to allocate state data\n");
+		ret = -ENOMEM;
+		goto err_memgpio;
+	}
+	drvdata->nr_states = config->nr_states;
+
+	drvdata->desc.owner = THIS_MODULE;
+	drvdata->desc.enable_time = config->startup_delay;
+
+	/* handle regulator type*/
+	switch (config->type) {
+	case REGULATOR_VOLTAGE:
+		drvdata->desc.type = REGULATOR_VOLTAGE;
+		drvdata->desc.ops = &gpio_regulator_voltage_ops;
+		drvdata->desc.n_voltages = config->nr_states;
+		break;
+	case REGULATOR_CURRENT:
+		drvdata->desc.type = REGULATOR_CURRENT;
+		drvdata->desc.ops = &gpio_regulator_current_ops;
+		break;
+	default:
+		dev_err(&pdev->dev, "No regulator type set\n");
+		ret = -EINVAL;
+		goto err_memgpio;
+	}
+
+	/* 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)
+			state |= (1 << ptr);
+	}
+	drvdata->state = state;
+
+	cfg.dev = &pdev->dev;
+	cfg.init_data = config->init_data;
+	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;
+		else
+			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
+	}
+
+	drvdata->dev = regulator_register(&drvdata->desc, &cfg);
+	if (IS_ERR(drvdata->dev)) {
+		ret = PTR_ERR(drvdata->dev);
+		dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
+		goto err_stategpio;
+	}
+
+	platform_set_drvdata(pdev, drvdata);
+
+	return 0;
+
+err_stategpio:
+	gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
+err_memstate:
+	kfree(drvdata->states);
+err_memgpio:
+	kfree(drvdata->gpios);
+err_name:
+	kfree(drvdata->desc.name);
+err:
+	return ret;
+}
+
+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;
+}
+
+#if defined(CONFIG_OF)
+static const struct of_device_id regulator_gpio_of_match[] = {
+	{ .compatible = "regulator-gpio", },
+	{},
+};
+#endif
+
+static struct platform_driver gpio_regulator_driver = {
+	.probe		= gpio_regulator_probe,
+	.remove		= gpio_regulator_remove,
+	.driver		= {
+		.name		= "gpio-regulator",
+		.of_match_table = of_match_ptr(regulator_gpio_of_match),
+	},
+};
+
+static int __init gpio_regulator_init(void)
+{
+	return platform_driver_register(&gpio_regulator_driver);
+}
+subsys_initcall(gpio_regulator_init);
+
+static void __exit gpio_regulator_exit(void)
+{
+	platform_driver_unregister(&gpio_regulator_driver);
+}
+module_exit(gpio_regulator_exit);
+
+MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
+MODULE_DESCRIPTION("gpio voltage regulator");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:gpio-regulator");