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 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 35 static 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 ensure 43 * the device will have a clean state after powering up, just like the 44 * 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 67 static 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 79 static 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 } 112 113 static 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 }; 117 118 static const struct of_device_id goodix_i2c_hid_of_match[] = { 119 { .compatible = "goodix,gt7375p", .data = &goodix_gt7375p_timing_data }, 120 { } 121 }; 122 MODULE_DEVICE_TABLE(of, goodix_i2c_hid_of_match); 123 124 static 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 }; 135 module_i2c_driver(goodix_i2c_hid_ts_driver); 136 137 MODULE_AUTHOR("Douglas Anderson <dianders@chromium.org>"); 138 MODULE_DESCRIPTION("Goodix i2c-hid touchscreen driver"); 139 MODULE_LICENSE("GPL v2"); 140