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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 <asm/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 regulator *vcc;
29 struct regulator *vio;
30 struct touchscreen_properties prop;
31 struct regulator_bulk_data supplies[2];
32 u16 max_x;
33 u16 max_y;
34 u8 fingernum;
35};
36
37static int zet6223_start(struct input_dev *dev)
38{
39 struct zet6223_ts *ts = input_get_drvdata(dev);
40
41 enable_irq(ts->client->irq);
42
43 return 0;
44}
45
46static void zet6223_stop(struct input_dev *dev)
47{
48 struct zet6223_ts *ts = input_get_drvdata(dev);
49
50 disable_irq(ts->client->irq);
51}
52
53static irqreturn_t zet6223_irq(int irq, void *dev_id)
54{
55 struct zet6223_ts *ts = dev_id;
56 u16 finger_bits;
57
58
59
60
61
62 u8 bufsize = 3 + 4 * ts->fingernum;
63 u8 buf[ZET6223_MAX_PKT_SIZE];
64 int i;
65 int ret;
66 int error;
67
68 ret = i2c_master_recv(ts->client, buf, bufsize);
69 if (ret != bufsize) {
70 error = ret < 0 ? ret : -EIO;
71 dev_err_ratelimited(&ts->client->dev,
72 "Error reading input data: %d\n", error);
73 return IRQ_HANDLED;
74 }
75
76 if (buf[0] != ZET6223_VALID_PACKET)
77 return IRQ_HANDLED;
78
79 finger_bits = get_unaligned_be16(buf + 1);
80 for (i = 0; i < ts->fingernum; i++) {
81 if (!(finger_bits & BIT(15 - i)))
82 continue;
83
84 input_mt_slot(ts->input, i);
85 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
86 input_event(ts->input, EV_ABS, ABS_MT_POSITION_X,
87 ((buf[i + 3] >> 4) << 8) + buf[i + 4]);
88 input_event(ts->input, EV_ABS, ABS_MT_POSITION_Y,
89 ((buf[i + 3] & 0xF) << 8) + buf[i + 5]);
90 }
91
92 input_mt_sync_frame(ts->input);
93 input_sync(ts->input);
94
95 return IRQ_HANDLED;
96}
97
98static void zet6223_power_off(void *_ts)
99{
100 struct zet6223_ts *ts = _ts;
101
102 regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
103}
104
105static int zet6223_power_on(struct zet6223_ts *ts)
106{
107 struct device *dev = &ts->client->dev;
108 int error;
109
110 ts->supplies[0].supply = "vio";
111 ts->supplies[1].supply = "vcc";
112
113 error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->supplies),
114 ts->supplies);
115 if (error)
116 return error;
117
118 error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
119 if (error)
120 return error;
121
122 msleep(ZET6223_POWER_ON_DELAY_MSEC);
123
124 error = devm_add_action_or_reset(dev, zet6223_power_off, ts);
125 if (error) {
126 dev_err(dev, "failed to install poweroff action: %d\n", error);
127 return error;
128 }
129
130 return 0;
131}
132
133static int zet6223_query_device(struct zet6223_ts *ts)
134{
135 u8 buf[ZET6223_CMD_INFO_LENGTH];
136 u8 cmd = ZET6223_CMD_INFO;
137 int ret;
138 int error;
139
140 ret = i2c_master_send(ts->client, &cmd, sizeof(cmd));
141 if (ret != sizeof(cmd)) {
142 error = ret < 0 ? ret : -EIO;
143 dev_err(&ts->client->dev,
144 "touchpanel info cmd failed: %d\n", error);
145 return error;
146 }
147
148 ret = i2c_master_recv(ts->client, buf, sizeof(buf));
149 if (ret != sizeof(buf)) {
150 error = ret < 0 ? ret : -EIO;
151 dev_err(&ts->client->dev,
152 "failed to retrieve touchpanel info: %d\n", error);
153 return error;
154 }
155
156 ts->fingernum = buf[15] & 0x7F;
157 if (ts->fingernum > ZET6223_MAX_FINGERS) {
158 dev_warn(&ts->client->dev,
159 "touchpanel reports %d fingers, limiting to %d\n",
160 ts->fingernum, ZET6223_MAX_FINGERS);
161 ts->fingernum = ZET6223_MAX_FINGERS;
162 }
163
164 ts->max_x = get_unaligned_le16(&buf[8]);
165 ts->max_y = get_unaligned_le16(&buf[10]);
166
167 return 0;
168}
169
170static int zet6223_probe(struct i2c_client *client,
171 const struct i2c_device_id *id)
172{
173 struct device *dev = &client->dev;
174 struct zet6223_ts *ts;
175 struct input_dev *input;
176 int error;
177
178 if (!client->irq) {
179 dev_err(dev, "no irq specified\n");
180 return -EINVAL;
181 }
182
183 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
184 if (!ts)
185 return -ENOMEM;
186
187 ts->client = client;
188
189 error = zet6223_power_on(ts);
190 if (error)
191 return error;
192
193 error = zet6223_query_device(ts);
194 if (error)
195 return error;
196
197 ts->input = input = devm_input_allocate_device(dev);
198 if (!input)
199 return -ENOMEM;
200
201 input_set_drvdata(input, ts);
202
203 input->name = client->name;
204 input->id.bustype = BUS_I2C;
205 input->open = zet6223_start;
206 input->close = zet6223_stop;
207
208 input_set_abs_params(input, ABS_MT_POSITION_X, 0, ts->max_x, 0, 0);
209 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ts->max_y, 0, 0);
210
211 touchscreen_parse_properties(input, true, &ts->prop);
212
213 error = input_mt_init_slots(input, ts->fingernum,
214 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
215 if (error)
216 return error;
217
218 error = devm_request_threaded_irq(dev, client->irq, NULL, zet6223_irq,
219 IRQF_ONESHOT, client->name, ts);
220 if (error) {
221 dev_err(dev, "failed to request irq %d: %d\n",
222 client->irq, error);
223 return error;
224 }
225
226 zet6223_stop(input);
227
228 error = input_register_device(input);
229 if (error)
230 return error;
231
232 return 0;
233}
234
235static const struct of_device_id zet6223_of_match[] = {
236 { .compatible = "zeitec,zet6223" },
237 { }
238};
239MODULE_DEVICE_TABLE(of, zet6223_of_match);
240
241static const struct i2c_device_id zet6223_id[] = {
242 { "zet6223", 0},
243 { }
244};
245MODULE_DEVICE_TABLE(i2c, zet6223_id);
246
247static struct i2c_driver zet6223_driver = {
248 .driver = {
249 .name = "zet6223",
250 .of_match_table = zet6223_of_match,
251 },
252 .probe = zet6223_probe,
253 .id_table = zet6223_id
254};
255module_i2c_driver(zet6223_driver);
256
257MODULE_AUTHOR("Jelle van der Waa <jelle@vdwaa.nl>");
258MODULE_DESCRIPTION("ZEITEC zet622x I2C touchscreen driver");
259MODULE_LICENSE("GPL");
260
