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// SPDX-License-Identifier: GPL-2.0
/*
* Driver for Goodix touchscreens that use the i2c-hid protocol.
*
* Copyright 2020 Google LLC
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pm.h>
#include <linux/regulator/consumer.h>
#include "i2c-hid.h"
struct goodix_i2c_hid_timing_data {
unsigned int post_gpio_reset_delay_ms;
unsigned int post_power_delay_ms;
};
struct i2c_hid_of_goodix {
struct i2chid_ops ops;
struct regulator *vdd;
struct regulator *vddio;
struct gpio_desc *reset_gpio;
bool no_reset_during_suspend;
const struct goodix_i2c_hid_timing_data *timings;
};
static int goodix_i2c_hid_power_up(struct i2chid_ops *ops)
{
struct i2c_hid_of_goodix *ihid_goodix =
container_of(ops, struct i2c_hid_of_goodix, ops);
int ret;
/*
* We assert reset GPIO here (instead of during power-down) to ensure
* the device will have a clean state after powering up, just like the
* normal scenarios will have.
*/
if (ihid_goodix->no_reset_during_suspend)
gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1);
ret = regulator_enable(ihid_goodix->vdd);
if (ret)
return ret;
ret = regulator_enable(ihid_goodix->vddio);
if (ret)
return ret;
if (ihid_goodix->timings->post_power_delay_ms)
msleep(ihid_goodix->timings->post_power_delay_ms);
gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 0);
if (ihid_goodix->timings->post_gpio_reset_delay_ms)
msleep(ihid_goodix->timings->post_gpio_reset_delay_ms);
return 0;
}
static void goodix_i2c_hid_power_down(struct i2chid_ops *ops)
{
struct i2c_hid_of_goodix *ihid_goodix =
container_of(ops, struct i2c_hid_of_goodix, ops);
if (!ihid_goodix->no_reset_during_suspend)
gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1);
regulator_disable(ihid_goodix->vddio);
regulator_disable(ihid_goodix->vdd);
}
static int i2c_hid_of_goodix_probe(struct i2c_client *client)
{
struct i2c_hid_of_goodix *ihid_goodix;
ihid_goodix = devm_kzalloc(&client->dev, sizeof(*ihid_goodix),
GFP_KERNEL);
if (!ihid_goodix)
return -ENOMEM;
ihid_goodix->ops.power_up = goodix_i2c_hid_power_up;
ihid_goodix->ops.power_down = goodix_i2c_hid_power_down;
/* Start out with reset asserted */
ihid_goodix->reset_gpio =
devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);
if (IS_ERR(ihid_goodix->reset_gpio))
return PTR_ERR(ihid_goodix->reset_gpio);
ihid_goodix->vdd = devm_regulator_get(&client->dev, "vdd");
if (IS_ERR(ihid_goodix->vdd))
return PTR_ERR(ihid_goodix->vdd);
ihid_goodix->vddio = devm_regulator_get(&client->dev, "mainboard-vddio");
if (IS_ERR(ihid_goodix->vddio))
return PTR_ERR(ihid_goodix->vddio);
ihid_goodix->no_reset_during_suspend =
of_property_read_bool(client->dev.of_node, "goodix,no-reset-during-suspend");
ihid_goodix->timings = device_get_match_data(&client->dev);
return i2c_hid_core_probe(client, &ihid_goodix->ops, 0x0001, 0);
}
static const struct goodix_i2c_hid_timing_data goodix_gt7375p_timing_data = {
.post_power_delay_ms = 10,
.post_gpio_reset_delay_ms = 180,
};
static const struct of_device_id goodix_i2c_hid_of_match[] = {
{ .compatible = "goodix,gt7375p", .data = &goodix_gt7375p_timing_data },
{ }
};
MODULE_DEVICE_TABLE(of, goodix_i2c_hid_of_match);
static struct i2c_driver goodix_i2c_hid_ts_driver = {
.driver = {
.name = "i2c_hid_of_goodix",
.pm = &i2c_hid_core_pm,
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
.of_match_table = of_match_ptr(goodix_i2c_hid_of_match),
},
.probe = i2c_hid_of_goodix_probe,
.remove = i2c_hid_core_remove,
.shutdown = i2c_hid_core_shutdown,
};
module_i2c_driver(goodix_i2c_hid_ts_driver);
MODULE_AUTHOR("Douglas Anderson <dianders@chromium.org>");
MODULE_DESCRIPTION("Goodix i2c-hid touchscreen driver");
MODULE_LICENSE("GPL v2");
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