1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Driver for Goodix touchscreens that use the i2c-hid protocol. 4 * 5 * Copyright 2020 Google LLC 6 */ 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 20 struct goodix_i2c_hid_timing_data { 21 unsigned int post_gpio_reset_delay_ms; 22 unsigned int post_power_delay_ms; 23 }; 24 25 struct i2c_hid_of_goodix { 26 struct i2chid_ops ops; 27 28 struct regulator *vdd; 29 struct gpio_desc *reset_gpio; 30 const struct goodix_i2c_hid_timing_data *timings; 31 }; 32 33 static int goodix_i2c_hid_power_up(struct i2chid_ops *ops) 34 { 35 struct i2c_hid_of_goodix *ihid_goodix = 36 container_of(ops, struct i2c_hid_of_goodix, ops); 37 int ret; 38 39 ret = regulator_enable(ihid_goodix->vdd); 40 if (ret) 41 return ret; 42 43 if (ihid_goodix->timings->post_power_delay_ms) 44 msleep(ihid_goodix->timings->post_power_delay_ms); 45 46 gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 0); 47 if (ihid_goodix->timings->post_gpio_reset_delay_ms) 48 msleep(ihid_goodix->timings->post_gpio_reset_delay_ms); 49 50 return 0; 51 } 52 53 static void goodix_i2c_hid_power_down(struct i2chid_ops *ops) 54 { 55 struct i2c_hid_of_goodix *ihid_goodix = 56 container_of(ops, struct i2c_hid_of_goodix, ops); 57 58 gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); 59 regulator_disable(ihid_goodix->vdd); 60 } 61 62 static int i2c_hid_of_goodix_probe(struct i2c_client *client, 63 const struct i2c_device_id *id) 64 { 65 struct i2c_hid_of_goodix *ihid_goodix; 66 67 ihid_goodix = devm_kzalloc(&client->dev, sizeof(*ihid_goodix), 68 GFP_KERNEL); 69 if (!ihid_goodix) 70 return -ENOMEM; 71 72 ihid_goodix->ops.power_up = goodix_i2c_hid_power_up; 73 ihid_goodix->ops.power_down = goodix_i2c_hid_power_down; 74 75 /* Start out with reset asserted */ 76 ihid_goodix->reset_gpio = 77 devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH); 78 if (IS_ERR(ihid_goodix->reset_gpio)) 79 return PTR_ERR(ihid_goodix->reset_gpio); 80 81 ihid_goodix->vdd = devm_regulator_get(&client->dev, "vdd"); 82 if (IS_ERR(ihid_goodix->vdd)) 83 return PTR_ERR(ihid_goodix->vdd); 84 85 ihid_goodix->timings = device_get_match_data(&client->dev); 86 87 return i2c_hid_core_probe(client, &ihid_goodix->ops, 0x0001); 88 } 89 90 static const struct goodix_i2c_hid_timing_data goodix_gt7375p_timing_data = { 91 .post_power_delay_ms = 10, 92 .post_gpio_reset_delay_ms = 180, 93 }; 94 95 static const struct of_device_id goodix_i2c_hid_of_match[] = { 96 { .compatible = "goodix,gt7375p", .data = &goodix_gt7375p_timing_data }, 97 { } 98 }; 99 MODULE_DEVICE_TABLE(of, goodix_i2c_hid_of_match); 100 101 static struct i2c_driver goodix_i2c_hid_ts_driver = { 102 .driver = { 103 .name = "i2c_hid_of_goodix", 104 .pm = &i2c_hid_core_pm, 105 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 106 .of_match_table = of_match_ptr(goodix_i2c_hid_of_match), 107 }, 108 .probe = i2c_hid_of_goodix_probe, 109 .remove = i2c_hid_core_remove, 110 .shutdown = i2c_hid_core_shutdown, 111 }; 112 module_i2c_driver(goodix_i2c_hid_ts_driver); 113 114 MODULE_AUTHOR("Douglas Anderson <dianders@chromium.org>"); 115 MODULE_DESCRIPTION("Goodix i2c-hid touchscreen driver"); 116 MODULE_LICENSE("GPL v2"); 117