vexpress.c
3.74 KB
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/*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Copyright (C) 2012 ARM Limited
*/
#define DRVNAME "vexpress-regulator"
#define pr_fmt(fmt) DRVNAME ": " fmt
#include <linux/device.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
#include <linux/vexpress.h>
struct vexpress_regulator {
struct regulator_desc desc;
struct regulator_dev *regdev;
struct vexpress_config_func *func;
};
static int vexpress_regulator_get_voltage(struct regulator_dev *regdev)
{
struct vexpress_regulator *reg = rdev_get_drvdata(regdev);
u32 uV;
int err = vexpress_config_read(reg->func, 0, &uV);
return err ? err : uV;
}
static int vexpress_regulator_set_voltage(struct regulator_dev *regdev,
int min_uV, int max_uV, unsigned *selector)
{
struct vexpress_regulator *reg = rdev_get_drvdata(regdev);
return vexpress_config_write(reg->func, 0, min_uV);
}
static struct regulator_ops vexpress_regulator_ops_ro = {
.get_voltage = vexpress_regulator_get_voltage,
};
static struct regulator_ops vexpress_regulator_ops = {
.get_voltage = vexpress_regulator_get_voltage,
.set_voltage = vexpress_regulator_set_voltage,
};
static int vexpress_regulator_probe(struct platform_device *pdev)
{
int err;
struct vexpress_regulator *reg;
struct regulator_init_data *init_data;
struct regulator_config config = { };
reg = devm_kzalloc(&pdev->dev, sizeof(*reg), GFP_KERNEL);
if (!reg) {
err = -ENOMEM;
goto error_kzalloc;
}
reg->func = vexpress_config_func_get_by_dev(&pdev->dev);
if (!reg->func) {
err = -ENXIO;
goto error_get_func;
}
reg->desc.name = dev_name(&pdev->dev);
reg->desc.type = REGULATOR_VOLTAGE;
reg->desc.owner = THIS_MODULE;
reg->desc.continuous_voltage_range = true;
init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node);
if (!init_data) {
err = -EINVAL;
goto error_get_regulator_init_data;
}
init_data->constraints.apply_uV = 0;
if (init_data->constraints.min_uV && init_data->constraints.max_uV)
reg->desc.ops = &vexpress_regulator_ops;
else
reg->desc.ops = &vexpress_regulator_ops_ro;
config.dev = &pdev->dev;
config.init_data = init_data;
config.driver_data = reg;
config.of_node = pdev->dev.of_node;
reg->regdev = devm_regulator_register(&pdev->dev, ®->desc, &config);
if (IS_ERR(reg->regdev)) {
err = PTR_ERR(reg->regdev);
goto error_regulator_register;
}
platform_set_drvdata(pdev, reg);
return 0;
error_regulator_register:
error_get_regulator_init_data:
vexpress_config_func_put(reg->func);
error_get_func:
error_kzalloc:
return err;
}
static int vexpress_regulator_remove(struct platform_device *pdev)
{
struct vexpress_regulator *reg = platform_get_drvdata(pdev);
vexpress_config_func_put(reg->func);
return 0;
}
static struct of_device_id vexpress_regulator_of_match[] = {
{ .compatible = "arm,vexpress-volt", },
{ }
};
static struct platform_driver vexpress_regulator_driver = {
.probe = vexpress_regulator_probe,
.remove = vexpress_regulator_remove,
.driver = {
.name = DRVNAME,
.owner = THIS_MODULE,
.of_match_table = vexpress_regulator_of_match,
},
};
module_platform_driver(vexpress_regulator_driver);
MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
MODULE_DESCRIPTION("Versatile Express regulator");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:vexpress-regulator");