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