1 files changed, 301 insertions, 0 deletions
diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
new file mode 100644
index 000000000..4acfff190
--- /dev/null
+++ b/drivers/regulator/fixed.c
@@ -0,0 +1,301 @@
+// 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/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 clk_enable_counter;
+};
+
+struct fixed_dev_type {
+	bool has_enable_clock;
+};
+
+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->clk_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->clk_enable_counter--;
+
+	return 0;
+}
+
+static int reg_clock_is_enabled(struct regulator_dev *rdev)
+{
+	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
+
+	return priv->clk_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_clock_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 {
+		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) {
+			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;
+
+	/*
+	 * 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 PTR_ERR(cfg.ena_gpiod);
+
+	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 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 of_device_id fixed_of_match[] = {
+	{
+		.compatible = "regulator-fixed",
+		.data = &fixed_voltage_data,
+	},
+	{
+		.compatible = "regulator-fixed-clock",
+		.data = &fixed_clkenable_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(&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");