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Diffstat (limited to '')
-rw-r--r-- | drivers/regulator/fixed.c | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c new file mode 100644 index 000000000..e6724a229 --- /dev/null +++ b/drivers/regulator/fixed.c @@ -0,0 +1,356 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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 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/pm_domain.h> +#include <linux/pm_opp.h> +#include <linux/regulator/driver.h> +#include <linux/regulator/fixed.h> +#include <linux/gpio/consumer.h> +#include <linux/slab.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/regulator/of_regulator.h> +#include <linux/regulator/machine.h> +#include <linux/clk.h> + + +struct fixed_voltage_data { + struct regulator_desc desc; + struct regulator_dev *dev; + + struct clk *enable_clock; + unsigned int enable_counter; + int performance_state; +}; + +struct fixed_dev_type { + bool has_enable_clock; + bool has_performance_state; +}; + +static int reg_clock_enable(struct regulator_dev *rdev) +{ + struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); + int ret = 0; + + ret = clk_prepare_enable(priv->enable_clock); + if (ret) + return ret; + + priv->enable_counter++; + + return ret; +} + +static int reg_clock_disable(struct regulator_dev *rdev) +{ + struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); + + clk_disable_unprepare(priv->enable_clock); + priv->enable_counter--; + + return 0; +} + +static int reg_domain_enable(struct regulator_dev *rdev) +{ + struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); + struct device *dev = rdev->dev.parent; + int ret; + + ret = dev_pm_genpd_set_performance_state(dev, priv->performance_state); + if (ret) + return ret; + + priv->enable_counter++; + + return ret; +} + +static int reg_domain_disable(struct regulator_dev *rdev) +{ + struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); + struct device *dev = rdev->dev.parent; + int ret; + + ret = dev_pm_genpd_set_performance_state(dev, 0); + if (ret) + return ret; + + priv->enable_counter--; + + return 0; +} + +static int reg_is_enabled(struct regulator_dev *rdev) +{ + struct fixed_voltage_data *priv = rdev_get_drvdata(rdev); + + return priv->enable_counter > 0; +} + + +/** + * 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; + + of_property_read_u32(np, "startup-delay-us", &config->startup_delay); + of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay); + + if (of_find_property(np, "vin-supply", NULL)) + config->input_supply = "vin"; + + return config; +} + +static const struct regulator_ops fixed_voltage_ops = { +}; + +static const struct regulator_ops fixed_voltage_clkenabled_ops = { + .enable = reg_clock_enable, + .disable = reg_clock_disable, + .is_enabled = reg_is_enabled, +}; + +static const struct regulator_ops fixed_voltage_domain_ops = { + .enable = reg_domain_enable, + .disable = reg_domain_disable, + .is_enabled = reg_is_enabled, +}; + +static int reg_fixed_voltage_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct fixed_voltage_config *config; + struct fixed_voltage_data *drvdata; + const struct fixed_dev_type *drvtype = of_device_get_match_data(dev); + struct regulator_config cfg = { }; + enum gpiod_flags gflags; + 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; + + if (drvtype && drvtype->has_enable_clock) { + drvdata->desc.ops = &fixed_voltage_clkenabled_ops; + + drvdata->enable_clock = devm_clk_get(dev, NULL); + if (IS_ERR(drvdata->enable_clock)) { + dev_err(dev, "Can't get enable-clock from devicetree\n"); + return PTR_ERR(drvdata->enable_clock); + } + } else if (drvtype && drvtype->has_performance_state) { + drvdata->desc.ops = &fixed_voltage_domain_ops; + + drvdata->performance_state = of_get_required_opp_performance_state(dev->of_node, 0); + if (drvdata->performance_state < 0) { + dev_err(dev, "Can't get performance state from devicetree\n"); + return drvdata->performance_state; + } + } else { + drvdata->desc.ops = &fixed_voltage_ops; + } + + drvdata->desc.enable_time = config->startup_delay; + drvdata->desc.off_on_delay = config->off_on_delay; + + if (config->input_supply) { + drvdata->desc.supply_name = devm_kstrdup(&pdev->dev, + config->input_supply, + GFP_KERNEL); + if (!drvdata->desc.supply_name) + return -ENOMEM; + } + + if (config->microvolts) + drvdata->desc.n_voltages = 1; + + drvdata->desc.fixed_uV = config->microvolts; + + /* + * The signal will be inverted by the GPIO core if flagged so in the + * descriptor. + */ + if (config->enabled_at_boot) + gflags = GPIOD_OUT_HIGH; + else + gflags = GPIOD_OUT_LOW; + + /* + * Some fixed regulators share the enable line between two + * regulators which makes it necessary to get a handle on the + * same descriptor for two different consumers. This will get + * the GPIO descriptor, but only the first call will initialize + * it so any flags such as inversion or open drain will only + * be set up by the first caller and assumed identical on the + * next caller. + * + * FIXME: find a better way to deal with this. + */ + gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE; + + /* + * Do not use devm* here: the regulator core takes over the + * lifecycle management of the GPIO descriptor. + */ + cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags); + if (IS_ERR(cfg.ena_gpiod)) + return dev_err_probe(&pdev->dev, PTR_ERR(cfg.ena_gpiod), + "can't get GPIO\n"); + + 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 = dev_err_probe(&pdev->dev, PTR_ERR(drvdata->dev), + "Failed to register regulator: %ld\n", + PTR_ERR(drvdata->dev)); + 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 fixed_dev_type fixed_voltage_data = { + .has_enable_clock = false, +}; + +static const struct fixed_dev_type fixed_clkenable_data = { + .has_enable_clock = true, +}; + +static const struct fixed_dev_type fixed_domain_data = { + .has_performance_state = true, +}; + +static const struct of_device_id fixed_of_match[] = { + { + .compatible = "regulator-fixed", + .data = &fixed_voltage_data, + }, + { + .compatible = "regulator-fixed-clock", + .data = &fixed_clkenable_data, + }, + { + .compatible = "regulator-fixed-domain", + .data = &fixed_domain_data, + }, + { + }, +}; +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"); |