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(desc: ihid_goodix->reset_gpio, value: 1); |
48 | |
49 | ret = regulator_enable(regulator: ihid_goodix->vdd); |
50 | if (ret) |
51 | return ret; |
52 | |
53 | ret = regulator_enable(regulator: ihid_goodix->vddio); |
54 | if (ret) |
55 | return ret; |
56 | |
57 | if (ihid_goodix->timings->post_power_delay_ms) |
58 | msleep(msecs: ihid_goodix->timings->post_power_delay_ms); |
59 | |
60 | gpiod_set_value_cansleep(desc: ihid_goodix->reset_gpio, value: 0); |
61 | if (ihid_goodix->timings->post_gpio_reset_delay_ms) |
62 | msleep(msecs: 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(desc: ihid_goodix->reset_gpio, value: 1); |
74 | |
75 | regulator_disable(regulator: ihid_goodix->vddio); |
76 | regulator_disable(regulator: 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(dev: &client->dev, size: 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(dev: &client->dev, con_id: "reset" , flags: GPIOD_OUT_HIGH); |
94 | if (IS_ERR(ptr: ihid_goodix->reset_gpio)) |
95 | return PTR_ERR(ptr: ihid_goodix->reset_gpio); |
96 | |
97 | ihid_goodix->vdd = devm_regulator_get(dev: &client->dev, id: "vdd" ); |
98 | if (IS_ERR(ptr: ihid_goodix->vdd)) |
99 | return PTR_ERR(ptr: ihid_goodix->vdd); |
100 | |
101 | ihid_goodix->vddio = devm_regulator_get(dev: &client->dev, id: "mainboard-vddio" ); |
102 | if (IS_ERR(ptr: ihid_goodix->vddio)) |
103 | return PTR_ERR(ptr: ihid_goodix->vddio); |
104 | |
105 | ihid_goodix->no_reset_during_suspend = |
106 | of_property_read_bool(np: client->dev.of_node, propname: "goodix,no-reset-during-suspend" ); |
107 | |
108 | ihid_goodix->timings = device_get_match_data(dev: &client->dev); |
109 | |
110 | return i2c_hid_core_probe(client, ops: &ihid_goodix->ops, hid_descriptor_address: 0x0001, quirks: 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 | |