--- /dev/null
+/*
+ * 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", ®type);
+ 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");
Code Review / kvmfornfv.git / blobdiff