| // 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/reboot.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/regulator/of_regulator.h> |
| #include <linux/regulator/machine.h> |
| #include <linux/clk.h> |
| |
| /* Default time in millisecond to wait for emergency shutdown */ |
| #define FV_DEF_EMERG_SHUTDWN_TMO 10 |
| |
| 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; |
| } |
| |
| static irqreturn_t reg_fixed_under_voltage_irq_handler(int irq, void *data) |
| { |
| struct fixed_voltage_data *priv = data; |
| struct regulator_dev *rdev = priv->dev; |
| |
| regulator_notifier_call_chain(rdev, REGULATOR_EVENT_UNDER_VOLTAGE, |
| NULL); |
| |
| return IRQ_HANDLED; |
| } |
| |
| /** |
| * reg_fixed_get_irqs - Get and register the optional IRQ for fixed voltage |
| * regulator. |
| * @dev: Pointer to the device structure. |
| * @priv: Pointer to fixed_voltage_data structure containing private data. |
| * |
| * This function tries to get the IRQ from the device firmware node. |
| * If it's an optional IRQ and not found, it returns 0. |
| * Otherwise, it attempts to request the threaded IRQ. |
| * |
| * Return: 0 on success, or a negative error number on failure. |
| */ |
| static int reg_fixed_get_irqs(struct device *dev, |
| struct fixed_voltage_data *priv) |
| { |
| int ret; |
| |
| ret = fwnode_irq_get(dev_fwnode(dev), 0); |
| /* This is optional IRQ. If not found we will get -EINVAL */ |
| if (ret == -EINVAL) |
| return 0; |
| if (ret < 0) |
| return dev_err_probe(dev, ret, "Failed to get IRQ\n"); |
| |
| ret = devm_request_threaded_irq(dev, ret, NULL, |
| reg_fixed_under_voltage_irq_handler, |
| IRQF_ONESHOT, "under-voltage", priv); |
| if (ret) |
| return dev_err_probe(dev, ret, "Failed to request IRQ\n"); |
| |
| return 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. |
| * |
| * Return: Pointer to a populated &struct fixed_voltage_config or %NULL if |
| * memory allocation 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_property_present(np, "vin-supply")) |
| 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); |
| |
| ret = reg_fixed_get_irqs(dev, drvdata); |
| if (ret) |
| return ret; |
| |
| 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", |
| .probe_type = PROBE_PREFER_ASYNCHRONOUS, |
| .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"); |