sy7636a-regulator.c
// SPDX-License-Identifier: GPL-2.0+
//
// Functions to access SY3686A power management chip voltages
//
// Copyright (C) 2019 reMarkable AS - http://www.remarkable.com/
//
// Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>
// Alistair Francis <alistair@alistair23.me>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/gpio/consumer.h>
#include <linux/mfd/sy7636a.h>
struct sy7636a_data {
struct regmap *regmap;
struct gpio_desc *pgood_gpio;
};
static int sy7636a_get_vcom_voltage_op(struct regulator_dev *rdev)
{
int ret;
unsigned int val, val_h;
ret = regmap_read(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, &val);
if (ret)
return ret;
ret = regmap_read(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, &val_h);
if (ret)
return ret;
val |= (val_h << VCOM_ADJUST_CTRL_SHIFT);
return (val & VCOM_ADJUST_CTRL_MASK) * VCOM_ADJUST_CTRL_SCAL;
}
static int sy7636a_get_status(struct regulator_dev *rdev)
{
struct sy7636a_data *data = dev_get_drvdata(rdev->dev.parent);
int ret = 0;
ret = gpiod_get_value_cansleep(data->pgood_gpio);
if (ret < 0)
dev_err(&rdev->dev, "Failed to read pgood gpio: %d\n", ret);
return ret;
}
static const struct regulator_ops sy7636a_vcom_volt_ops = {
.get_voltage = sy7636a_get_vcom_voltage_op,
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.is_enabled = regulator_is_enabled_regmap,
.get_status = sy7636a_get_status,
};
static const struct regulator_desc desc = {
.name = "vcom",
.id = 0,
.ops = &sy7636a_vcom_volt_ops,
.type = REGULATOR_VOLTAGE,
.owner = THIS_MODULE,
.enable_reg = SY7636A_REG_OPERATION_MODE_CRL,
.enable_mask = SY7636A_OPERATION_MODE_CRL_ONOFF,
.regulators_node = of_match_ptr("regulators"),
.of_match = of_match_ptr("vcom"),
};
static int sy7636a_regulator_probe(struct platform_device *pdev)
{
struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL);
struct regulator_config config = { };
struct regulator_dev *rdev;
struct gpio_desc *gdp;
struct sy7636a_data *data;
int ret;
if (!regmap)
return -EPROBE_DEFER;
gdp = devm_gpiod_get(pdev->dev.parent, "epd-pwr-good", GPIOD_IN);
if (IS_ERR(gdp)) {
dev_err(pdev->dev.parent, "Power good GPIO fault %ld\n", PTR_ERR(gdp));
return PTR_ERR(gdp);
}
data = devm_kzalloc(&pdev->dev, sizeof(struct sy7636a_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->regmap = regmap;
data->pgood_gpio = gdp;
platform_set_drvdata(pdev, data);
ret = regmap_write(regmap, SY7636A_REG_POWER_ON_DELAY_TIME, 0x0);
if (ret) {
dev_err(pdev->dev.parent, "Failed to initialize regulator: %d\n", ret);
return ret;
}
config.dev = &pdev->dev;
config.dev->of_node = pdev->dev.parent->of_node;
config.regmap = regmap;
rdev = devm_regulator_register(&pdev->dev, &desc, &config);
if (IS_ERR(rdev)) {
dev_err(pdev->dev.parent, "Failed to register %s regulator\n",
pdev->name);
return PTR_ERR(rdev);
}
return 0;
}
static const struct platform_device_id sy7636a_regulator_id_table[] = {
{ "sy7636a-regulator", },
{ }
};
MODULE_DEVICE_TABLE(platform, sy7636a_regulator_id_table);
static struct platform_driver sy7636a_regulator_driver = {
.driver = {
.name = "sy7636a-regulator",
},
.probe = sy7636a_regulator_probe,
.id_table = sy7636a_regulator_id_table,
};
module_platform_driver(sy7636a_regulator_driver);
MODULE_AUTHOR("Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>");
MODULE_DESCRIPTION("SY7636A voltage regulator driver");
MODULE_LICENSE("GPL v2");