/* * 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");