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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2016, Jelle van der Waa <[email protected]>
4 */
5
6#include <linux/delay.h>
7#include <linux/i2c.h>
8#include <linux/input.h>
9#include <linux/input/mt.h>
10#include <linux/input/touchscreen.h>
11#include <linux/interrupt.h>
12#include <linux/module.h>
13#include <linux/regulator/consumer.h>
14#include <linux/unaligned.h>
15
16#define ZET6223_MAX_FINGERS 16
17#define ZET6223_MAX_PKT_SIZE (3 + 4 * ZET6223_MAX_FINGERS)
18
19#define ZET6223_CMD_INFO 0xB2
20#define ZET6223_CMD_INFO_LENGTH 17
21#define ZET6223_VALID_PACKET 0x3c
22
23#define ZET6223_POWER_ON_DELAY_MSEC 30
24
25struct zet6223_ts {
26 struct i2c_client *client;
27 struct input_dev *input;
28 struct touchscreen_properties prop;
29 struct regulator_bulk_data supplies[2];
30 u16 max_x;
31 u16 max_y;
32 u8 fingernum;
33};
34
35static int zet6223_start(struct input_dev *dev)
36{
37 struct zet6223_ts *ts = input_get_drvdata(dev);
38
39 enable_irq(ts->client->irq);
40
41 return 0;
42}
43
44static void zet6223_stop(struct input_dev *dev)
45{
46 struct zet6223_ts *ts = input_get_drvdata(dev);
47
48 disable_irq(ts->client->irq);
49}
50
51static irqreturn_t zet6223_irq(int irq, void *dev_id)
52{
53 struct zet6223_ts *ts = dev_id;
54 u16 finger_bits;
55
56 /*
57 * First 3 bytes are an identifier, two bytes of finger data.
58 * X, Y data per finger is 4 bytes.
59 */
60 u8 bufsize = 3 + 4 * ts->fingernum;
61 u8 buf[ZET6223_MAX_PKT_SIZE];
62 int i;
63 int ret;
64 int error;
65
66 ret = i2c_master_recv(ts->client, buf, bufsize);
67 if (ret != bufsize) {
68 error = ret < 0 ? ret : -EIO;
69 dev_err_ratelimited(&ts->client->dev,
70 "Error reading input data: %d\n", error);
71 return IRQ_HANDLED;
72 }
73
74 if (buf[0] != ZET6223_VALID_PACKET)
75 return IRQ_HANDLED;
76
77 finger_bits = get_unaligned_be16(buf + 1);
78 for (i = 0; i < ts->fingernum; i++) {
79 if (!(finger_bits & BIT(15 - i)))
80 continue;
81
82 input_mt_slot(ts->input, i);
83 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
84 input_event(ts->input, EV_ABS, ABS_MT_POSITION_X,
85 ((buf[i + 3] >> 4) << 8) + buf[i + 4]);
86 input_event(ts->input, EV_ABS, ABS_MT_POSITION_Y,
87 ((buf[i + 3] & 0xF) << 8) + buf[i + 5]);
88 }
89
90 input_mt_sync_frame(ts->input);
91 input_sync(ts->input);
92
93 return IRQ_HANDLED;
94}
95
96static void zet6223_power_off(void *_ts)
97{
98 struct zet6223_ts *ts = _ts;
99
100 regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
101}
102
103static int zet6223_power_on(struct zet6223_ts *ts)
104{
105 struct device *dev = &ts->client->dev;
106 int error;
107
108 ts->supplies[0].supply = "vio";
109 ts->supplies[1].supply = "vcc";
110
111 error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->supplies),
112 ts->supplies);
113 if (error)
114 return error;
115
116 error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
117 if (error)
118 return error;
119
120 msleep(ZET6223_POWER_ON_DELAY_MSEC);
121
122 error = devm_add_action_or_reset(dev, zet6223_power_off, ts);
123 if (error) {
124 dev_err(dev, "failed to install poweroff action: %d\n", error);
125 return error;
126 }
127
128 return 0;
129}
130
131static int zet6223_query_device(struct zet6223_ts *ts)
132{
133 u8 buf[ZET6223_CMD_INFO_LENGTH];
134 u8 cmd = ZET6223_CMD_INFO;
135 int ret;
136 int error;
137
138 ret = i2c_master_send(ts->client, &cmd, sizeof(cmd));
139 if (ret != sizeof(cmd)) {
140 error = ret < 0 ? ret : -EIO;
141 dev_err(&ts->client->dev,
142 "touchpanel info cmd failed: %d\n", error);
143 return error;
144 }
145
146 ret = i2c_master_recv(ts->client, buf, sizeof(buf));
147 if (ret != sizeof(buf)) {
148 error = ret < 0 ? ret : -EIO;
149 dev_err(&ts->client->dev,
150 "failed to retrieve touchpanel info: %d\n", error);
151 return error;
152 }
153
154 ts->fingernum = buf[15] & 0x7F;
155 if (ts->fingernum > ZET6223_MAX_FINGERS) {
156 dev_warn(&ts->client->dev,
157 "touchpanel reports %d fingers, limiting to %d\n",
158 ts->fingernum, ZET6223_MAX_FINGERS);
159 ts->fingernum = ZET6223_MAX_FINGERS;
160 }
161
162 ts->max_x = get_unaligned_le16(&buf[8]);
163 ts->max_y = get_unaligned_le16(&buf[10]);
164
165 return 0;
166}
167
168static int zet6223_probe(struct i2c_client *client)
169{
170 struct device *dev = &client->dev;
171 struct zet6223_ts *ts;
172 struct input_dev *input;
173 int error;
174
175 if (!client->irq) {
176 dev_err(dev, "no irq specified\n");
177 return -EINVAL;
178 }
179
180 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
181 if (!ts)
182 return -ENOMEM;
183
184 ts->client = client;
185
186 error = zet6223_power_on(ts);
187 if (error)
188 return error;
189
190 error = zet6223_query_device(ts);
191 if (error)
192 return error;
193
194 ts->input = input = devm_input_allocate_device(dev);
195 if (!input)
196 return -ENOMEM;
197
198 input_set_drvdata(input, ts);
199
200 input->name = client->name;
201 input->id.bustype = BUS_I2C;
202 input->open = zet6223_start;
203 input->close = zet6223_stop;
204
205 input_set_abs_params(input, ABS_MT_POSITION_X, 0, ts->max_x, 0, 0);
206 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ts->max_y, 0, 0);
207
208 touchscreen_parse_properties(input, true, &ts->prop);
209
210 error = input_mt_init_slots(input, ts->fingernum,
211 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
212 if (error)
213 return error;
214
215 error = devm_request_threaded_irq(dev, client->irq, NULL, zet6223_irq,
216 IRQF_ONESHOT, client->name, ts);
217 if (error) {
218 dev_err(dev, "failed to request irq %d: %d\n",
219 client->irq, error);
220 return error;
221 }
222
223 zet6223_stop(input);
224
225 error = input_register_device(input);
226 if (error)
227 return error;
228
229 return 0;
230}
231
232static const struct of_device_id zet6223_of_match[] = {
233 { .compatible = "zeitec,zet6223" },
234 { }
235};
236MODULE_DEVICE_TABLE(of, zet6223_of_match);
237
238static const struct i2c_device_id zet6223_id[] = {
239 { .name = "zet6223" },
240 { }
241};
242MODULE_DEVICE_TABLE(i2c, zet6223_id);
243
244static struct i2c_driver zet6223_driver = {
245 .driver = {
246 .name = "zet6223",
247 .of_match_table = zet6223_of_match,
248 },
249 .probe = zet6223_probe,
250 .id_table = zet6223_id
251};
252module_i2c_driver(zet6223_driver);
253
254MODULE_AUTHOR("Jelle van der Waa <[email protected]>");
255MODULE_DESCRIPTION("ZEITEC zet622x I2C touchscreen driver");
256MODULE_LICENSE("GPL");