/* * 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/gpio-regulator.h> #include <linux/gpio.h> #include <linux/slab.h> struct gpio_regulator_data { struct regulator_desc desc; struct regulator_dev *dev; int enable_gpio; bool enable_high; bool is_enabled; unsigned startup_delay; struct gpio *gpios; int nr_gpios; struct gpio_regulator_state *states; int nr_states; int state; }; static int gpio_regulator_is_enabled(struct regulator_dev *dev) { struct gpio_regulator_data *data = rdev_get_drvdata(dev); return data->is_enabled; } static int gpio_regulator_enable(struct regulator_dev *dev) { struct gpio_regulator_data *data = rdev_get_drvdata(dev); if (gpio_is_valid(data->enable_gpio)) { gpio_set_value_cansleep(data->enable_gpio, data->enable_high); data->is_enabled = true; } return 0; } static int gpio_regulator_disable(struct regulator_dev *dev) { struct gpio_regulator_data *data = rdev_get_drvdata(dev); if (gpio_is_valid(data->enable_gpio)) { gpio_set_value_cansleep(data->enable_gpio, !data->enable_high); data->is_enabled = false; } return 0; } static int gpio_regulator_enable_time(struct regulator_dev *dev) { struct gpio_regulator_data *data = rdev_get_drvdata(dev); return data->startup_delay; } 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_value(struct regulator_dev *dev, int min, int max, 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 && data->states[ptr].value <= max) { 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(data->gpios[ptr].gpio, state); } data->state = target; return 0; } static int gpio_regulator_set_voltage(struct regulator_dev *dev, int min_uV, int max_uV, unsigned *selector) { return gpio_regulator_set_value(dev, min_uV, max_uV, selector); } 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) { return gpio_regulator_set_value(dev, min_uA, max_uA, NULL); } static struct regulator_ops gpio_regulator_voltage_ops = { .is_enabled = gpio_regulator_is_enabled, .enable = gpio_regulator_enable, .disable = gpio_regulator_disable, .enable_time = gpio_regulator_enable_time, .get_voltage = gpio_regulator_get_value, .set_voltage = gpio_regulator_set_voltage, .list_voltage = gpio_regulator_list_voltage, }; static struct regulator_ops gpio_regulator_current_ops = { .is_enabled = gpio_regulator_is_enabled, .enable = gpio_regulator_enable, .disable = gpio_regulator_disable, .enable_time = gpio_regulator_enable_time, .get_current_limit = gpio_regulator_get_value, .set_current_limit = gpio_regulator_set_current_limit, }; static int __devinit gpio_regulator_probe(struct platform_device *pdev) { struct gpio_regulator_config *config = pdev->dev.platform_data; 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) { 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; /* 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->enable_gpio = config->enable_gpio; drvdata->startup_delay = config->startup_delay; if (gpio_is_valid(config->enable_gpio)) { drvdata->enable_high = config->enable_high; ret = gpio_request(config->enable_gpio, config->supply_name); if (ret) { dev_err(&pdev->dev, "Could not obtain regulator enable GPIO %d: %d\n", config->enable_gpio, ret); goto err_memstate; } /* set output direction without changing state * to prevent glitch */ if (config->enabled_at_boot) { drvdata->is_enabled = true; ret = gpio_direction_output(config->enable_gpio, config->enable_high); } else { drvdata->is_enabled = false; ret = gpio_direction_output(config->enable_gpio, !config->enable_high); } if (ret) { dev_err(&pdev->dev, "Could not configure regulator enable GPIO %d direction: %d\n", config->enable_gpio, ret); goto err_enablegpio; } } else { /* Regulator without GPIO control is considered * always enabled */ drvdata->is_enabled = true; } 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_enablegpio; } /* 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; 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_enablegpio: if (gpio_is_valid(config->enable_gpio)) gpio_free(config->enable_gpio); err_memstate: kfree(drvdata->states); err_memgpio: kfree(drvdata->gpios); err_name: kfree(drvdata->desc.name); err: return ret; } static int __devexit 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); if (gpio_is_valid(drvdata->enable_gpio)) gpio_free(drvdata->enable_gpio); kfree(drvdata->desc.name); return 0; } static struct platform_driver gpio_regulator_driver = { .probe = gpio_regulator_probe, .remove = __devexit_p(gpio_regulator_remove), .driver = { .name = "gpio-regulator", .owner = THIS_MODULE, }, }; 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");