/* * 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/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. */static 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, dev->of_node);	if (!config->init_data)		return NULL; 	init_data = config->init_data;	init_data->constraints.apply_uV = 0; 	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; 	if (of_find_property(np, "gpio-open-drain", NULL))		config->gpio_is_open_drain = 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); 	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); 	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); 	if (data->microvolts)		return data->microvolts;	else		return -EINVAL;} 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_gpio_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 struct regulator_ops fixed_voltage_ops = {	.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;	struct fixed_voltage_data *drvdata;	struct regulator_config cfg = { };	int ret; 	if (pdev->dev.of_node)		config = of_get_fixed_voltage_config(&pdev->dev);	else		config = pdev->dev.platform_data; 	if (!config)		return -ENOMEM; 	drvdata = devm_kzalloc(&pdev->dev, 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; 	if (config->microvolts)		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)) {		int gpio_flag;		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"); 		/*		 * 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;		gpio_flag = ret ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; 		if (config->gpio_is_open_drain)			gpio_flag |= GPIOF_OPEN_DRAIN; 		ret = gpio_request_one(config->gpio, gpio_flag,						config->supply_name);		if (ret) {			dev_err(&pdev->dev,			   "Could not obtain regulator enable GPIO %d: %d\n",							config->gpio, ret);			goto err_name;		} 		drvdata->desc.ops = &fixed_voltage_gpio_ops; 	} else {		drvdata->desc.ops = &fixed_voltage_ops;	} 	cfg.dev = &pdev->dev;	cfg.init_data = config->init_data;	cfg.driver_data = drvdata;	cfg.of_node = pdev->dev.of_node; 	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_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:	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); 	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(&regulator_fixed_voltage_driver);}subsys_initcall(regulator_fixed_voltage_init); static void __exit regulator_fixed_voltage_exit(void){	platform_driver_unregister(&regulator_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");