diff options
Diffstat (limited to 'kernel/drivers/regulator/fixed.c')
| -rw-r--r-- | kernel/drivers/regulator/fixed.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/kernel/drivers/regulator/fixed.c b/kernel/drivers/regulator/fixed.c new file mode 100644 index 000000000..ff62d69ba --- /dev/null +++ b/kernel/drivers/regulator/fixed.c @@ -0,0 +1,235 @@ +/* + * 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 + * @desc: regulator description + * + * 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, + const struct regulator_desc *desc) +{ + 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, desc); + 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; + + drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data), + GFP_KERNEL); + if (!drvdata) + return -ENOMEM; + + if (pdev->dev.of_node) { + config = of_get_fixed_voltage_config(&pdev->dev, + &drvdata->desc); + if (IS_ERR(config)) + return PTR_ERR(config); + } else { + config = dev_get_platdata(&pdev->dev); + } + + if (!config) + 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 (gpio_is_valid(config->gpio)) { + cfg.ena_gpio = config->gpio; + if (pdev->dev.of_node) + 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; + } + 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", + .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"); |