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1// SPDX-License-Identifier: GPL-2.02/*3 * Driver for Goodix touchscreens that use the i2c-hid protocol.4 *5 * Copyright 2020 Google LLC6 */7 8#include <linux/delay.h>9#include <linux/device.h>10#include <linux/gpio/consumer.h>11#include <linux/i2c.h>12#include <linux/kernel.h>13#include <linux/module.h>14#include <linux/of.h>15#include <linux/pm.h>16#include <linux/regulator/consumer.h>17 18#include "i2c-hid.h"19 20struct goodix_i2c_hid_timing_data {21 unsigned int post_gpio_reset_delay_ms;22 unsigned int post_power_delay_ms;23};24 25struct i2c_hid_of_goodix {26 struct i2chid_ops ops;27 28 struct regulator *vdd;29 struct regulator *vddio;30 struct gpio_desc *reset_gpio;31 bool no_reset_during_suspend;32 const struct goodix_i2c_hid_timing_data *timings;33};34 35static int goodix_i2c_hid_power_up(struct i2chid_ops *ops)36{37 struct i2c_hid_of_goodix *ihid_goodix =38 container_of(ops, struct i2c_hid_of_goodix, ops);39 int ret;40 41 /*42 * We assert reset GPIO here (instead of during power-down) to ensure43 * the device will have a clean state after powering up, just like the44 * normal scenarios will have.45 */46 if (ihid_goodix->no_reset_during_suspend)47 gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1);48 49 ret = regulator_enable(ihid_goodix->vdd);50 if (ret)51 return ret;52 53 ret = regulator_enable(ihid_goodix->vddio);54 if (ret)55 return ret;56 57 if (ihid_goodix->timings->post_power_delay_ms)58 msleep(ihid_goodix->timings->post_power_delay_ms);59 60 gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 0);61 if (ihid_goodix->timings->post_gpio_reset_delay_ms)62 msleep(ihid_goodix->timings->post_gpio_reset_delay_ms);63 64 return 0;65}66 67static void goodix_i2c_hid_power_down(struct i2chid_ops *ops)68{69 struct i2c_hid_of_goodix *ihid_goodix =70 container_of(ops, struct i2c_hid_of_goodix, ops);71 72 if (!ihid_goodix->no_reset_during_suspend)73 gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1);74 75 regulator_disable(ihid_goodix->vddio);76 regulator_disable(ihid_goodix->vdd);77}78 79static int i2c_hid_of_goodix_probe(struct i2c_client *client)80{81 struct i2c_hid_of_goodix *ihid_goodix;82 83 ihid_goodix = devm_kzalloc(&client->dev, sizeof(*ihid_goodix),84 GFP_KERNEL);85 if (!ihid_goodix)86 return -ENOMEM;87 88 ihid_goodix->ops.power_up = goodix_i2c_hid_power_up;89 ihid_goodix->ops.power_down = goodix_i2c_hid_power_down;90 91 /* Start out with reset asserted */92 ihid_goodix->reset_gpio =93 devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);94 if (IS_ERR(ihid_goodix->reset_gpio))95 return PTR_ERR(ihid_goodix->reset_gpio);96 97 ihid_goodix->vdd = devm_regulator_get(&client->dev, "vdd");98 if (IS_ERR(ihid_goodix->vdd))99 return PTR_ERR(ihid_goodix->vdd);100 101 ihid_goodix->vddio = devm_regulator_get(&client->dev, "mainboard-vddio");102 if (IS_ERR(ihid_goodix->vddio))103 return PTR_ERR(ihid_goodix->vddio);104 105 ihid_goodix->no_reset_during_suspend =106 of_property_read_bool(client->dev.of_node, "goodix,no-reset-during-suspend");107 108 ihid_goodix->timings = device_get_match_data(&client->dev);109 110 return i2c_hid_core_probe(client, &ihid_goodix->ops, 0x0001, 0);111}112 113static const struct goodix_i2c_hid_timing_data goodix_gt7375p_timing_data = {114 .post_power_delay_ms = 10,115 .post_gpio_reset_delay_ms = 180,116};117 118static const struct of_device_id goodix_i2c_hid_of_match[] = {119 { .compatible = "goodix,gt7375p", .data = &goodix_gt7375p_timing_data },120 { }121};122MODULE_DEVICE_TABLE(of, goodix_i2c_hid_of_match);123 124static struct i2c_driver goodix_i2c_hid_ts_driver = {125 .driver = {126 .name = "i2c_hid_of_goodix",127 .pm = &i2c_hid_core_pm,128 .probe_type = PROBE_PREFER_ASYNCHRONOUS,129 .of_match_table = of_match_ptr(goodix_i2c_hid_of_match),130 },131 .probe = i2c_hid_of_goodix_probe,132 .remove = i2c_hid_core_remove,133 .shutdown = i2c_hid_core_shutdown,134};135module_i2c_driver(goodix_i2c_hid_ts_driver);136 137MODULE_AUTHOR("Douglas Anderson <dianders@chromium.org>");138MODULE_DESCRIPTION("Goodix i2c-hid touchscreen driver");139MODULE_LICENSE("GPL v2");140