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