diff options
Diffstat (limited to 'drivers/regulator/gpio-regulator.c')
| -rw-r--r-- | drivers/regulator/gpio-regulator.c | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/drivers/regulator/gpio-regulator.c b/drivers/regulator/gpio-regulator.c new file mode 100644 index 0000000..9d39eb4 --- /dev/null +++ b/drivers/regulator/gpio-regulator.c @@ -0,0 +1,396 @@ +/* + * 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) +{ + struct gpio_regulator_config *config; + struct property *prop; + const char *regtype; + int proplen, gpio, i; + + 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); + 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. */ + config->nr_gpios = of_gpio_count(np); + + config->gpios = devm_kzalloc(dev, + sizeof(struct gpio) * config->nr_gpios, + GFP_KERNEL); + if (!config->gpios) + return ERR_PTR(-ENOMEM); + + 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; + } + + /* Fetch states. */ + prop = of_find_property(np, "states", NULL); + if (!prop) { + dev_err(dev, "No 'states' property found\n"); + return ERR_PTR(-EINVAL); + } + + proplen = prop->length / sizeof(int); + + 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++) { + config->states[i].value = + be32_to_cpup((int *)prop->value + (i * 2)); + config->states[i].gpios = + be32_to_cpup((int *)prop->value + (i * 2 + 1)); + } + config->nr_states = i; + + of_property_read_string(np, "regulator-type", ®type); + + if (!strncmp("voltage", regtype, 7)) + config->type = REGULATOR_VOLTAGE; + else if (!strncmp("current", regtype, 7)) + config->type = REGULATOR_CURRENT; + + 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 = pdev->dev.platform_data; + struct device_node *np = pdev->dev.of_node; + struct gpio_regulator_data *drvdata; + struct regulator_config cfg = { }; + int ptr, ret, state; + + if (np) { + config = of_get_gpio_regulator_config(&pdev->dev, np); + if (IS_ERR(config)) + return PTR_ERR(config); + } + + drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data), + GFP_KERNEL); + if (drvdata == NULL) { + dev_err(&pdev->dev, "Failed to allocate device data\n"); + return -ENOMEM; + } + + 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; + } + + 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->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; + break; + } + + 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; + } + + /* 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 (config->enable_gpio >= 0) + cfg.ena_gpio = config->enable_gpio; + 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", + .owner = THIS_MODULE, + .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"); |