| /* |
| * 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/fixed.h> |
| #include <linux/gpio.h> |
| #include <linux/delay.h> |
| #include <linux/slab.h> |
| #include <linux/of.h> |
| #include <linux/of_gpio.h> |
| #include <linux/regulator/of_regulator.h> |
| #include <linux/regulator/machine.h> |
| |
| struct fixed_voltage_data { |
| struct regulator_desc desc; |
| struct regulator_dev *dev; |
| int microvolts; |
| int gpio; |
| unsigned startup_delay; |
| bool enable_high; |
| bool is_enabled; |
| }; |
| |
| |
| /** |
| * of_get_fixed_voltage_config - extract fixed_voltage_config structure info |
| * @dev: device requesting for fixed_voltage_config |
| * |
| * Populates fixed_voltage_config structure by extracting data from device |
| * tree node, returns a pointer to the populated structure of NULL if memory |
| * alloc fails. |
| */ |
| struct fixed_voltage_config *of_get_fixed_voltage_config(struct device *dev) |
| { |
| struct fixed_voltage_config *config; |
| struct device_node *np = dev->of_node; |
| const __be32 *delay; |
| struct regulator_init_data *init_data; |
| |
| config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config), |
| GFP_KERNEL); |
| if (!config) |
| return NULL; |
| |
| config->init_data = of_get_regulator_init_data(dev); |
| init_data = config->init_data; |
| |
| config->supply_name = init_data->constraints.name; |
| if (init_data->constraints.min_uV == init_data->constraints.max_uV) { |
| config->microvolts = init_data->constraints.min_uV; |
| } else { |
| dev_err(dev, |
| "Fixed regulator specified with variable voltages\n"); |
| return NULL; |
| } |
| |
| if (init_data->constraints.boot_on) |
| config->enabled_at_boot = true; |
| |
| config->gpio = of_get_named_gpio(np, "gpio", 0); |
| delay = of_get_property(np, "startup-delay-us", NULL); |
| if (delay) |
| config->startup_delay = be32_to_cpu(*delay); |
| |
| if (of_find_property(np, "enable-active-high", NULL)) |
| config->enable_high = true; |
| |
| return config; |
| } |
| |
| static int fixed_voltage_is_enabled(struct regulator_dev *dev) |
| { |
| struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
| |
| return data->is_enabled; |
| } |
| |
| static int fixed_voltage_enable(struct regulator_dev *dev) |
| { |
| struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
| |
| if (gpio_is_valid(data->gpio)) { |
| gpio_set_value_cansleep(data->gpio, data->enable_high); |
| data->is_enabled = true; |
| } |
| |
| return 0; |
| } |
| |
| static int fixed_voltage_disable(struct regulator_dev *dev) |
| { |
| struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
| |
| if (gpio_is_valid(data->gpio)) { |
| gpio_set_value_cansleep(data->gpio, !data->enable_high); |
| data->is_enabled = false; |
| } |
| |
| return 0; |
| } |
| |
| static int fixed_voltage_enable_time(struct regulator_dev *dev) |
| { |
| struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
| |
| return data->startup_delay; |
| } |
| |
| static int fixed_voltage_get_voltage(struct regulator_dev *dev) |
| { |
| struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
| |
| return data->microvolts; |
| } |
| |
| static int fixed_voltage_list_voltage(struct regulator_dev *dev, |
| unsigned selector) |
| { |
| struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
| |
| if (selector != 0) |
| return -EINVAL; |
| |
| return data->microvolts; |
| } |
| |
| static struct regulator_ops fixed_voltage_ops = { |
| .is_enabled = fixed_voltage_is_enabled, |
| .enable = fixed_voltage_enable, |
| .disable = fixed_voltage_disable, |
| .enable_time = fixed_voltage_enable_time, |
| .get_voltage = fixed_voltage_get_voltage, |
| .list_voltage = fixed_voltage_list_voltage, |
| }; |
| |
| static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev) |
| { |
| struct fixed_voltage_config *config = pdev->dev.platform_data; |
| struct fixed_voltage_data *drvdata; |
| int ret; |
| |
| if (pdev->dev.of_node) |
| config = of_get_fixed_voltage_config(&pdev->dev); |
| |
| drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL); |
| if (drvdata == NULL) { |
| dev_err(&pdev->dev, "Failed to allocate device data\n"); |
| ret = -ENOMEM; |
| goto err; |
| } |
| |
| 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->desc.type = REGULATOR_VOLTAGE; |
| drvdata->desc.owner = THIS_MODULE; |
| drvdata->desc.ops = &fixed_voltage_ops; |
| drvdata->desc.n_voltages = 1; |
| |
| drvdata->microvolts = config->microvolts; |
| drvdata->gpio = config->gpio; |
| drvdata->startup_delay = config->startup_delay; |
| |
| if (gpio_is_valid(config->gpio)) { |
| drvdata->enable_high = config->enable_high; |
| |
| /* FIXME: Remove below print warning |
| * |
| * config->gpio must be set to -EINVAL by platform code if |
| * GPIO control is not required. However, early adopters |
| * not requiring GPIO control may forget to initialize |
| * config->gpio to -EINVAL. This will cause GPIO 0 to be used |
| * for GPIO control. |
| * |
| * This warning will be removed once there are a couple of users |
| * for this driver. |
| */ |
| if (!config->gpio) |
| dev_warn(&pdev->dev, |
| "using GPIO 0 for regulator enable control\n"); |
| |
| ret = gpio_request(config->gpio, config->supply_name); |
| if (ret) { |
| dev_err(&pdev->dev, |
| "Could not obtain regulator enable GPIO %d: %d\n", |
| config->gpio, ret); |
| goto err_name; |
| } |
| |
| /* set output direction without changing state |
| * to prevent glitch |
| */ |
| drvdata->is_enabled = config->enabled_at_boot; |
| ret = drvdata->is_enabled ? |
| config->enable_high : !config->enable_high; |
| |
| ret = gpio_direction_output(config->gpio, ret); |
| if (ret) { |
| dev_err(&pdev->dev, |
| "Could not configure regulator enable GPIO %d direction: %d\n", |
| config->gpio, ret); |
| goto err_gpio; |
| } |
| |
| } else { |
| /* Regulator without GPIO control is considered |
| * always enabled |
| */ |
| drvdata->is_enabled = true; |
| } |
| |
| drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev, |
| config->init_data, drvdata, NULL); |
| if (IS_ERR(drvdata->dev)) { |
| ret = PTR_ERR(drvdata->dev); |
| dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret); |
| goto err_gpio; |
| } |
| |
| platform_set_drvdata(pdev, drvdata); |
| |
| dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name, |
| drvdata->microvolts); |
| |
| return 0; |
| |
| err_gpio: |
| if (gpio_is_valid(config->gpio)) |
| gpio_free(config->gpio); |
| err_name: |
| kfree(drvdata->desc.name); |
| err: |
| kfree(drvdata); |
| return ret; |
| } |
| |
| static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev) |
| { |
| struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev); |
| |
| regulator_unregister(drvdata->dev); |
| if (gpio_is_valid(drvdata->gpio)) |
| gpio_free(drvdata->gpio); |
| kfree(drvdata->desc.name); |
| kfree(drvdata); |
| |
| return 0; |
| } |
| |
| #if defined(CONFIG_OF) |
| static const struct of_device_id fixed_of_match[] __devinitconst = { |
| { .compatible = "regulator-fixed", }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, fixed_of_match); |
| #else |
| #define fixed_of_match NULL |
| #endif |
| |
| static struct platform_driver regulator_fixed_voltage_driver = { |
| .probe = reg_fixed_voltage_probe, |
| .remove = __devexit_p(reg_fixed_voltage_remove), |
| .driver = { |
| .name = "reg-fixed-voltage", |
| .owner = THIS_MODULE, |
| .of_match_table = fixed_of_match, |
| }, |
| }; |
| |
| static int __init regulator_fixed_voltage_init(void) |
| { |
| return platform_driver_register(®ulator_fixed_voltage_driver); |
| } |
| subsys_initcall(regulator_fixed_voltage_init); |
| |
| static void __exit regulator_fixed_voltage_exit(void) |
| { |
| platform_driver_unregister(®ulator_fixed_voltage_driver); |
| } |
| module_exit(regulator_fixed_voltage_exit); |
| |
| MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); |
| MODULE_DESCRIPTION("Fixed voltage regulator"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:reg-fixed-voltage"); |