regulator: pwm-regulator: get voltage and duty table from dts
rename st-pwm to pwm-regulator. And support getting voltage & duty table from
device tree, other platforms can also use this driver without any modify.
Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
new file mode 100644
index 0000000..d3f55ea
--- /dev/null
+++ b/drivers/regulator/pwm-regulator.c
@@ -0,0 +1,197 @@
+/*
+ * Regulator driver for PWM Regulators
+ *
+ * Copyright (C) 2014 - STMicroelectronics Inc.
+ *
+ * Author: Lee Jones <lee.jones@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pwm.h>
+
+struct pwm_regulator_data {
+ struct regulator_desc desc;
+ struct pwm_voltages *duty_cycle_table;
+ struct pwm_device *pwm;
+ bool enabled;
+ int state;
+};
+
+struct pwm_voltages {
+ unsigned int uV;
+ unsigned int dutycycle;
+};
+
+static int pwm_regulator_get_voltage_sel(struct regulator_dev *dev)
+{
+ struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
+
+ return drvdata->state;
+}
+
+static int pwm_regulator_set_voltage_sel(struct regulator_dev *dev,
+ unsigned selector)
+{
+ struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
+ unsigned int pwm_reg_period;
+ int dutycycle;
+ int ret;
+
+ pwm_reg_period = pwm_get_period(drvdata->pwm);
+
+ dutycycle = (pwm_reg_period *
+ drvdata->duty_cycle_table[selector].dutycycle) / 100;
+
+ ret = pwm_config(drvdata->pwm, dutycycle, pwm_reg_period);
+ if (ret) {
+ dev_err(&dev->dev, "Failed to configure PWM\n");
+ return ret;
+ }
+
+ drvdata->state = selector;
+
+ if (!drvdata->enabled) {
+ ret = pwm_enable(drvdata->pwm);
+ if (ret) {
+ dev_err(&dev->dev, "Failed to enable PWM\n");
+ return ret;
+ }
+ drvdata->enabled = true;
+ }
+
+ return 0;
+}
+
+static int pwm_regulator_list_voltage(struct regulator_dev *dev,
+ unsigned selector)
+{
+ struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
+
+ if (selector >= drvdata->desc.n_voltages)
+ return -EINVAL;
+
+ return drvdata->duty_cycle_table[selector].uV;
+}
+
+static struct regulator_ops pwm_regulator_voltage_ops = {
+ .set_voltage_sel = pwm_regulator_set_voltage_sel,
+ .get_voltage_sel = pwm_regulator_get_voltage_sel,
+ .list_voltage = pwm_regulator_list_voltage,
+ .map_voltage = regulator_map_voltage_iterate,
+};
+
+static const struct regulator_desc pwm_regulator_desc = {
+ .name = "pwm-regulator",
+ .ops = &pwm_regulator_voltage_ops,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+ .supply_name = "pwm",
+};
+
+static int pwm_regulator_probe(struct platform_device *pdev)
+{
+ struct pwm_regulator_data *drvdata;
+ struct property *prop;
+ struct regulator_dev *regulator;
+ struct regulator_config config = { };
+ struct device_node *np = pdev->dev.of_node;
+ int length, ret;
+
+ if (!np) {
+ dev_err(&pdev->dev, "Device Tree node missing\n");
+ return -EINVAL;
+ }
+
+ drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
+
+ memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(pwm_regulator_desc));
+
+ /* determine the number of voltage-table */
+ prop = of_find_property(np, "voltage-table", &length);
+ if (!prop) {
+ dev_err(&pdev->dev, "No voltage-table\n");
+ return -EINVAL;
+ }
+
+ if ((length < sizeof(*drvdata->duty_cycle_table)) ||
+ (length % sizeof(*drvdata->duty_cycle_table))) {
+ dev_err(&pdev->dev, "voltage-table length(%d) is invalid\n",
+ length);
+ return -EINVAL;
+ }
+
+ drvdata->desc.n_voltages = length / sizeof(*drvdata->duty_cycle_table);
+
+ drvdata->duty_cycle_table = devm_kzalloc(&pdev->dev,
+ length, GFP_KERNEL);
+ if (!drvdata->duty_cycle_table)
+ return -ENOMEM;
+
+ /* read voltage table from DT property */
+ ret = of_property_read_u32_array(np, "voltage-table",
+ (u32 *)drvdata->duty_cycle_table,
+ length / sizeof(u32));
+ if (ret < 0) {
+ dev_err(&pdev->dev, "read voltage-table failed\n");
+ return ret;
+ }
+
+ config.init_data = of_get_regulator_init_data(&pdev->dev, np);
+ if (!config.init_data)
+ return -ENOMEM;
+
+ config.of_node = np;
+ config.dev = &pdev->dev;
+ config.driver_data = drvdata;
+
+ drvdata->pwm = devm_pwm_get(&pdev->dev, NULL);
+ if (IS_ERR(drvdata->pwm)) {
+ dev_err(&pdev->dev, "Failed to get PWM\n");
+ return PTR_ERR(drvdata->pwm);
+ }
+
+ regulator = devm_regulator_register(&pdev->dev,
+ &drvdata->desc, &config);
+ if (IS_ERR(regulator)) {
+ dev_err(&pdev->dev, "Failed to register regulator %s\n",
+ drvdata->desc.name);
+ return PTR_ERR(regulator);
+ }
+
+ return 0;
+}
+
+static const struct of_device_id pwm_of_match[] = {
+ { .compatible = "pwm-regulator" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, pwm_of_match);
+
+static struct platform_driver pwm_regulator_driver = {
+ .driver = {
+ .name = "pwm-regulator",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(pwm_of_match),
+ },
+ .probe = pwm_regulator_probe,
+};
+
+module_platform_driver(pwm_regulator_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>");
+MODULE_DESCRIPTION("PWM Regulator Driver");
+MODULE_ALIAS("platform:pwm-regulator");