/* * 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/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> 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; }; 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; 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); 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; } 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, }, }; 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");