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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* TI TPS380x Supply Voltage Supervisor and Reset Controller Driver
*
* Copyright (C) 2022 Pengutronix, Marco Felsch <kernel@pengutronix.de>
*
* Based on Simple Reset Controller Driver
*
* Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
*/
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/reset-controller.h>
struct tps380x_reset {
struct reset_controller_dev rcdev;
struct gpio_desc *reset_gpio;
unsigned int reset_ms;
};
struct tps380x_reset_devdata {
unsigned int min_reset_ms;
unsigned int typ_reset_ms;
unsigned int max_reset_ms;
};
static inline
struct tps380x_reset *to_tps380x_reset(struct reset_controller_dev *rcdev)
{
return container_of(rcdev, struct tps380x_reset, rcdev);
}
static int
tps380x_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
{
struct tps380x_reset *tps380x = to_tps380x_reset(rcdev);
gpiod_set_value_cansleep(tps380x->reset_gpio, 1);
return 0;
}
static int
tps380x_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
{
struct tps380x_reset *tps380x = to_tps380x_reset(rcdev);
gpiod_set_value_cansleep(tps380x->reset_gpio, 0);
msleep(tps380x->reset_ms);
return 0;
}
static const struct reset_control_ops reset_tps380x_ops = {
.assert = tps380x_reset_assert,
.deassert = tps380x_reset_deassert,
};
static int tps380x_reset_of_xlate(struct reset_controller_dev *rcdev,
const struct of_phandle_args *reset_spec)
{
/* No special handling needed, we have only one reset line per device */
return 0;
}
static int tps380x_reset_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct tps380x_reset_devdata *devdata;
struct tps380x_reset *tps380x;
devdata = device_get_match_data(dev);
if (!devdata)
return -EINVAL;
tps380x = devm_kzalloc(dev, sizeof(*tps380x), GFP_KERNEL);
if (!tps380x)
return -ENOMEM;
tps380x->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
if (IS_ERR(tps380x->reset_gpio))
return dev_err_probe(dev, PTR_ERR(tps380x->reset_gpio),
"Failed to get GPIO\n");
tps380x->reset_ms = devdata->max_reset_ms;
tps380x->rcdev.ops = &reset_tps380x_ops;
tps380x->rcdev.owner = THIS_MODULE;
tps380x->rcdev.dev = dev;
tps380x->rcdev.of_node = dev->of_node;
tps380x->rcdev.of_reset_n_cells = 0;
tps380x->rcdev.of_xlate = tps380x_reset_of_xlate;
tps380x->rcdev.nr_resets = 1;
return devm_reset_controller_register(dev, &tps380x->rcdev);
}
static const struct tps380x_reset_devdata tps3801_reset_data = {
.min_reset_ms = 120,
.typ_reset_ms = 200,
.max_reset_ms = 280,
};
static const struct of_device_id tps380x_reset_dt_ids[] = {
{ .compatible = "ti,tps3801", .data = &tps3801_reset_data },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, tps380x_reset_dt_ids);
static struct platform_driver tps380x_reset_driver = {
.probe = tps380x_reset_probe,
.driver = {
.name = "tps380x-reset",
.of_match_table = tps380x_reset_dt_ids,
},
};
module_platform_driver(tps380x_reset_driver);
MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>");
MODULE_DESCRIPTION("TI TPS380x Supply Voltage Supervisor and Reset Driver");
MODULE_LICENSE("GPL v2");
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