1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Driver for Elan 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 elan_i2c_hid_chip_data { |
21 | unsigned int post_gpio_reset_on_delay_ms; |
22 | unsigned int post_gpio_reset_off_delay_ms; |
23 | unsigned int post_power_delay_ms; |
24 | u16 hid_descriptor_address; |
25 | const char *main_supply_name; |
26 | }; |
27 | |
28 | struct i2c_hid_of_elan { |
29 | struct i2chid_ops ops; |
30 | |
31 | struct regulator *vcc33; |
32 | struct regulator *vccio; |
33 | struct gpio_desc *reset_gpio; |
34 | const struct elan_i2c_hid_chip_data *chip_data; |
35 | }; |
36 | |
37 | static int elan_i2c_hid_power_up(struct i2chid_ops *ops) |
38 | { |
39 | struct i2c_hid_of_elan *ihid_elan = |
40 | container_of(ops, struct i2c_hid_of_elan, ops); |
41 | int ret; |
42 | |
43 | if (ihid_elan->vcc33) { |
44 | ret = regulator_enable(regulator: ihid_elan->vcc33); |
45 | if (ret) |
46 | return ret; |
47 | } |
48 | |
49 | ret = regulator_enable(regulator: ihid_elan->vccio); |
50 | if (ret) { |
51 | regulator_disable(regulator: ihid_elan->vcc33); |
52 | return ret; |
53 | } |
54 | |
55 | if (ihid_elan->chip_data->post_power_delay_ms) |
56 | msleep(msecs: ihid_elan->chip_data->post_power_delay_ms); |
57 | |
58 | gpiod_set_value_cansleep(desc: ihid_elan->reset_gpio, value: 0); |
59 | if (ihid_elan->chip_data->post_gpio_reset_on_delay_ms) |
60 | msleep(msecs: ihid_elan->chip_data->post_gpio_reset_on_delay_ms); |
61 | |
62 | return 0; |
63 | } |
64 | |
65 | static void elan_i2c_hid_power_down(struct i2chid_ops *ops) |
66 | { |
67 | struct i2c_hid_of_elan *ihid_elan = |
68 | container_of(ops, struct i2c_hid_of_elan, ops); |
69 | |
70 | gpiod_set_value_cansleep(desc: ihid_elan->reset_gpio, value: 1); |
71 | if (ihid_elan->chip_data->post_gpio_reset_off_delay_ms) |
72 | msleep(msecs: ihid_elan->chip_data->post_gpio_reset_off_delay_ms); |
73 | |
74 | regulator_disable(regulator: ihid_elan->vccio); |
75 | if (ihid_elan->vcc33) |
76 | regulator_disable(regulator: ihid_elan->vcc33); |
77 | } |
78 | |
79 | static int i2c_hid_of_elan_probe(struct i2c_client *client) |
80 | { |
81 | struct i2c_hid_of_elan *ihid_elan; |
82 | |
83 | ihid_elan = devm_kzalloc(dev: &client->dev, size: sizeof(*ihid_elan), GFP_KERNEL); |
84 | if (!ihid_elan) |
85 | return -ENOMEM; |
86 | |
87 | ihid_elan->ops.power_up = elan_i2c_hid_power_up; |
88 | ihid_elan->ops.power_down = elan_i2c_hid_power_down; |
89 | |
90 | /* Start out with reset asserted */ |
91 | ihid_elan->reset_gpio = |
92 | devm_gpiod_get_optional(dev: &client->dev, con_id: "reset" , flags: GPIOD_OUT_HIGH); |
93 | if (IS_ERR(ptr: ihid_elan->reset_gpio)) |
94 | return PTR_ERR(ptr: ihid_elan->reset_gpio); |
95 | |
96 | ihid_elan->vccio = devm_regulator_get(dev: &client->dev, id: "vccio" ); |
97 | if (IS_ERR(ptr: ihid_elan->vccio)) |
98 | return PTR_ERR(ptr: ihid_elan->vccio); |
99 | |
100 | ihid_elan->chip_data = device_get_match_data(dev: &client->dev); |
101 | |
102 | if (ihid_elan->chip_data->main_supply_name) { |
103 | ihid_elan->vcc33 = devm_regulator_get(dev: &client->dev, |
104 | id: ihid_elan->chip_data->main_supply_name); |
105 | if (IS_ERR(ptr: ihid_elan->vcc33)) |
106 | return PTR_ERR(ptr: ihid_elan->vcc33); |
107 | } |
108 | |
109 | return i2c_hid_core_probe(client, ops: &ihid_elan->ops, |
110 | hid_descriptor_address: ihid_elan->chip_data->hid_descriptor_address, quirks: 0); |
111 | } |
112 | |
113 | static const struct elan_i2c_hid_chip_data elan_ekth6915_chip_data = { |
114 | .post_power_delay_ms = 1, |
115 | .post_gpio_reset_on_delay_ms = 300, |
116 | .hid_descriptor_address = 0x0001, |
117 | .main_supply_name = "vcc33" , |
118 | }; |
119 | |
120 | static const struct elan_i2c_hid_chip_data ilitek_ili9882t_chip_data = { |
121 | .post_power_delay_ms = 1, |
122 | .post_gpio_reset_on_delay_ms = 200, |
123 | .post_gpio_reset_off_delay_ms = 65, |
124 | .hid_descriptor_address = 0x0001, |
125 | /* |
126 | * this touchscreen is tightly integrated with the panel and assumes |
127 | * that the relevant power rails (other than the IO rail) have already |
128 | * been turned on by the panel driver because we're a panel follower. |
129 | */ |
130 | .main_supply_name = NULL, |
131 | }; |
132 | |
133 | static const struct elan_i2c_hid_chip_data ilitek_ili2901_chip_data = { |
134 | .post_power_delay_ms = 10, |
135 | .post_gpio_reset_on_delay_ms = 100, |
136 | .hid_descriptor_address = 0x0001, |
137 | .main_supply_name = "vcc33" , |
138 | }; |
139 | |
140 | static const struct of_device_id elan_i2c_hid_of_match[] = { |
141 | { .compatible = "elan,ekth6915" , .data = &elan_ekth6915_chip_data }, |
142 | { .compatible = "ilitek,ili9882t" , .data = &ilitek_ili9882t_chip_data }, |
143 | { .compatible = "ilitek,ili2901" , .data = &ilitek_ili2901_chip_data }, |
144 | { } |
145 | }; |
146 | MODULE_DEVICE_TABLE(of, elan_i2c_hid_of_match); |
147 | |
148 | static struct i2c_driver elan_i2c_hid_ts_driver = { |
149 | .driver = { |
150 | .name = "i2c_hid_of_elan" , |
151 | .pm = &i2c_hid_core_pm, |
152 | .probe_type = PROBE_PREFER_ASYNCHRONOUS, |
153 | .of_match_table = of_match_ptr(elan_i2c_hid_of_match), |
154 | }, |
155 | .probe = i2c_hid_of_elan_probe, |
156 | .remove = i2c_hid_core_remove, |
157 | .shutdown = i2c_hid_core_shutdown, |
158 | }; |
159 | module_i2c_driver(elan_i2c_hid_ts_driver); |
160 | |
161 | MODULE_AUTHOR("Douglas Anderson <dianders@chromium.org>" ); |
162 | MODULE_DESCRIPTION("Elan i2c-hid touchscreen driver" ); |
163 | MODULE_LICENSE("GPL" ); |
164 | |