/* * 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; }; /** * 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; struct regulator_init_data *init_data; config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config), GFP_KERNEL); if (!config) return ERR_PTR(-ENOMEM); config->init_data = of_get_regulator_init_data(dev, dev->of_node); if (!config->init_data) return ERR_PTR(-EINVAL); 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 ERR_PTR(-EINVAL); } if (init_data->constraints.boot_on) config->enabled_at_boot = true; config->gpio = of_get_named_gpio(np, "gpio", 0); /* * of_get_named_gpio() currently returns ENODEV rather than * EPROBE_DEFER. This code attempts to be compatible with both * for now; the ENODEV check can be removed once the API is fixed. * of_get_named_gpio() doesn't differentiate between a missing * property (which would be fine here, since the GPIO is optional) * and some other error. Patches have been posted for both issues. * Once they are check in, we should replace this with: * if (config->gpio < 0 && config->gpio != -ENOENT) */ if ((config->gpio == -ENODEV) || (config->gpio == -EPROBE_DEFER)) return ERR_PTR(-EPROBE_DEFER); of_property_read_u32(np, "startup-delay-us", &config->startup_delay); config->enable_high = of_property_read_bool(np, "enable-active-high"); config->gpio_is_open_drain = of_property_read_bool(np, "gpio-open-drain"); if (of_find_property(np, "vin-supply", NULL)) config->input_supply = "vin"; return config; } static struct regulator_ops fixed_voltage_ops = { }; static int 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); if (IS_ERR(config)) return PTR_ERR(config); } else { config = dev_get_platdata(&pdev->dev); } if (!config) return -ENOMEM; drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data), GFP_KERNEL); if (!drvdata) return -ENOMEM; drvdata->desc.name = devm_kstrdup(&pdev->dev, config->supply_name, GFP_KERNEL); if (drvdata->desc.name == NULL) { dev_err(&pdev->dev, "Failed to allocate supply name\n"); return -ENOMEM; } drvdata->desc.type = REGULATOR_VOLTAGE; drvdata->desc.owner = THIS_MODULE; drvdata->desc.ops = &fixed_voltage_ops; drvdata->desc.enable_time = config->startup_delay; if (config->input_supply) { drvdata->desc.supply_name = devm_kstrdup(&pdev->dev, config->input_supply, GFP_KERNEL); if (!drvdata->desc.supply_name) { dev_err(&pdev->dev, "Failed to allocate input supply\n"); return -ENOMEM; } } if (config->microvolts) drvdata->desc.n_voltages = 1; drvdata->desc.fixed_uV = config->microvolts; if (config->gpio >= 0) cfg.ena_gpio = config->gpio; 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; } if (config->gpio_is_open_drain) cfg.ena_gpio_flags |= GPIOF_OPEN_DRAIN; cfg.dev = &pdev->dev; cfg.init_data = config->init_data; cfg.driver_data = drvdata; cfg.of_node = pdev->dev.of_node; drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc, &cfg); if (IS_ERR(drvdata->dev)) { ret = PTR_ERR(drvdata->dev); dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret); return ret; } platform_set_drvdata(pdev, drvdata); dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name, drvdata->desc.fixed_uV); return 0; } #if defined(CONFIG_OF) static const struct of_device_id fixed_of_match[] = { { .compatible = "regulator-fixed", }, {}, }; MODULE_DEVICE_TABLE(of, fixed_of_match); #endif static struct platform_driver regulator_fixed_voltage_driver = { .probe = reg_fixed_voltage_probe, .driver = { .name = "reg-fixed-voltage", .owner = THIS_MODULE, .of_match_table = of_match_ptr(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");