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13#include <linux/delay.h>
14#include <linux/gpio/consumer.h>
15#include <linux/i2c.h>
16#include <linux/input.h>
17#include <linux/input/mt.h>
18#include <linux/input/touchscreen.h>
19#include <linux/interrupt.h>
20#include <linux/module.h>
21#include <linux/of.h>
22#include <linux/pm_qos.h>
23#include <linux/slab.h>
24#include <linux/types.h>
25
26#define ST1232_TS_NAME "st1232-ts"
27#define ST1633_TS_NAME "st1633-ts"
28
29#define REG_STATUS 0x01
30
31#define STATUS_NORMAL 0x00
32#define STATUS_INIT 0x01
33#define STATUS_ERROR 0x02
34#define STATUS_AUTO_TUNING 0x03
35#define STATUS_IDLE 0x04
36#define STATUS_POWER_DOWN 0x05
37
38#define ERROR_NONE 0x00
39#define ERROR_INVALID_ADDRESS 0x10
40#define ERROR_INVALID_VALUE 0x20
41#define ERROR_INVALID_PLATFORM 0x30
42
43#define REG_XY_RESOLUTION 0x04
44#define REG_XY_COORDINATES 0x12
45#define ST_TS_MAX_FINGERS 10
46
47struct st_chip_info {
48 bool have_z;
49 u16 max_area;
50 u16 max_fingers;
51};
52
53struct st1232_ts_data {
54 struct i2c_client *client;
55 struct input_dev *input_dev;
56 struct touchscreen_properties prop;
57 struct dev_pm_qos_request low_latency_req;
58 struct gpio_desc *reset_gpio;
59 const struct st_chip_info *chip_info;
60 int read_buf_len;
61 u8 *read_buf;
62};
63
64static int st1232_ts_read_data(struct st1232_ts_data *ts, u8 reg,
65 unsigned int n)
66{
67 struct i2c_client *client = ts->client;
68 struct i2c_msg msg[] = {
69 {
70 .addr = client->addr,
71 .len = sizeof(reg),
72 .buf = ®,
73 },
74 {
75 .addr = client->addr,
76 .flags = I2C_M_RD | I2C_M_DMA_SAFE,
77 .len = n,
78 .buf = ts->read_buf,
79 }
80 };
81 int ret;
82
83 ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
84 if (ret != ARRAY_SIZE(msg))
85 return ret < 0 ? ret : -EIO;
86
87 return 0;
88}
89
90static int st1232_ts_wait_ready(struct st1232_ts_data *ts)
91{
92 unsigned int retries;
93 int error;
94
95 for (retries = 10; retries; retries--) {
96 error = st1232_ts_read_data(ts, REG_STATUS, 1);
97 if (!error) {
98 switch (ts->read_buf[0]) {
99 case STATUS_NORMAL | ERROR_NONE:
100 case STATUS_IDLE | ERROR_NONE:
101 return 0;
102 }
103 }
104
105 usleep_range(1000, 2000);
106 }
107
108 return -ENXIO;
109}
110
111static int st1232_ts_read_resolution(struct st1232_ts_data *ts, u16 *max_x,
112 u16 *max_y)
113{
114 u8 *buf;
115 int error;
116
117
118 error = st1232_ts_read_data(ts, REG_XY_RESOLUTION, 3);
119 if (error)
120 return error;
121
122 buf = ts->read_buf;
123
124 *max_x = (((buf[0] & 0x0070) << 4) | buf[1]) - 1;
125 *max_y = (((buf[0] & 0x0007) << 8) | buf[2]) - 1;
126
127 return 0;
128}
129
130static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
131{
132 struct input_dev *input = ts->input_dev;
133 struct input_mt_pos pos[ST_TS_MAX_FINGERS];
134 u8 z[ST_TS_MAX_FINGERS];
135 int slots[ST_TS_MAX_FINGERS];
136 int n_contacts = 0;
137 int i;
138
139 for (i = 0; i < ts->chip_info->max_fingers; i++) {
140 u8 *buf = &ts->read_buf[i * 4];
141
142 if (buf[0] & BIT(7)) {
143 unsigned int x = ((buf[0] & 0x70) << 4) | buf[1];
144 unsigned int y = ((buf[0] & 0x07) << 8) | buf[2];
145
146 touchscreen_set_mt_pos(&pos[n_contacts],
147 &ts->prop, x, y);
148
149
150 if (ts->chip_info->have_z)
151 z[n_contacts] = ts->read_buf[i + 6];
152
153 n_contacts++;
154 }
155 }
156
157 input_mt_assign_slots(input, slots, pos, n_contacts, 0);
158 for (i = 0; i < n_contacts; i++) {
159 input_mt_slot(input, slots[i]);
160 input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
161 input_report_abs(input, ABS_MT_POSITION_X, pos[i].x);
162 input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y);
163 if (ts->chip_info->have_z)
164 input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]);
165 }
166
167 input_mt_sync_frame(input);
168 input_sync(input);
169
170 return n_contacts;
171}
172
173static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
174{
175 struct st1232_ts_data *ts = dev_id;
176 int count;
177 int error;
178
179 error = st1232_ts_read_data(ts, REG_XY_COORDINATES, ts->read_buf_len);
180 if (error)
181 goto out;
182
183 count = st1232_ts_parse_and_report(ts);
184 if (!count) {
185 if (ts->low_latency_req.dev) {
186 dev_pm_qos_remove_request(&ts->low_latency_req);
187 ts->low_latency_req.dev = NULL;
188 }
189 } else if (!ts->low_latency_req.dev) {
190
191 dev_pm_qos_add_ancestor_request(&ts->client->dev,
192 &ts->low_latency_req,
193 DEV_PM_QOS_RESUME_LATENCY, 100);
194 }
195
196out:
197 return IRQ_HANDLED;
198}
199
200static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
201{
202 if (ts->reset_gpio)
203 gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
204}
205
206static void st1232_ts_power_off(void *data)
207{
208 st1232_ts_power(data, false);
209}
210
211static const struct st_chip_info st1232_chip_info = {
212 .have_z = true,
213 .max_area = 0xff,
214 .max_fingers = 2,
215};
216
217static const struct st_chip_info st1633_chip_info = {
218 .have_z = false,
219 .max_area = 0x00,
220 .max_fingers = 5,
221};
222
223static int st1232_ts_probe(struct i2c_client *client,
224 const struct i2c_device_id *id)
225{
226 const struct st_chip_info *match;
227 struct st1232_ts_data *ts;
228 struct input_dev *input_dev;
229 u16 max_x, max_y;
230 int error;
231
232 match = device_get_match_data(&client->dev);
233 if (!match && id)
234 match = (const void *)id->driver_data;
235 if (!match) {
236 dev_err(&client->dev, "unknown device model\n");
237 return -ENODEV;
238 }
239
240 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
241 dev_err(&client->dev, "need I2C_FUNC_I2C\n");
242 return -EIO;
243 }
244
245 if (!client->irq) {
246 dev_err(&client->dev, "no IRQ?\n");
247 return -EINVAL;
248 }
249
250 ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
251 if (!ts)
252 return -ENOMEM;
253
254 ts->chip_info = match;
255
256
257 ts->read_buf_len = ts->chip_info->max_fingers * 4;
258 ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
259 if (!ts->read_buf)
260 return -ENOMEM;
261
262 input_dev = devm_input_allocate_device(&client->dev);
263 if (!input_dev)
264 return -ENOMEM;
265
266 ts->client = client;
267 ts->input_dev = input_dev;
268
269 ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
270 GPIOD_OUT_HIGH);
271 if (IS_ERR(ts->reset_gpio)) {
272 error = PTR_ERR(ts->reset_gpio);
273 dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
274 error);
275 return error;
276 }
277
278 st1232_ts_power(ts, true);
279
280 error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts);
281 if (error) {
282 dev_err(&client->dev,
283 "Failed to install power off action: %d\n", error);
284 return error;
285 }
286
287 input_dev->name = "st1232-touchscreen";
288 input_dev->id.bustype = BUS_I2C;
289
290
291 error = st1232_ts_wait_ready(ts);
292 if (error)
293 return error;
294
295
296 error = st1232_ts_read_resolution(ts, &max_x, &max_y);
297 if (error) {
298 dev_err(&client->dev,
299 "Failed to read resolution: %d\n", error);
300 return error;
301 }
302
303 if (ts->chip_info->have_z)
304 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
305 ts->chip_info->max_area, 0, 0);
306
307 input_set_abs_params(input_dev, ABS_MT_POSITION_X,
308 0, max_x, 0, 0);
309 input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
310 0, max_y, 0, 0);
311
312 touchscreen_parse_properties(input_dev, true, &ts->prop);
313
314 error = input_mt_init_slots(input_dev, ts->chip_info->max_fingers,
315 INPUT_MT_DIRECT | INPUT_MT_TRACK |
316 INPUT_MT_DROP_UNUSED);
317 if (error) {
318 dev_err(&client->dev, "failed to initialize MT slots\n");
319 return error;
320 }
321
322 error = devm_request_threaded_irq(&client->dev, client->irq,
323 NULL, st1232_ts_irq_handler,
324 IRQF_ONESHOT,
325 client->name, ts);
326 if (error) {
327 dev_err(&client->dev, "Failed to register interrupt\n");
328 return error;
329 }
330
331 error = input_register_device(ts->input_dev);
332 if (error) {
333 dev_err(&client->dev, "Unable to register %s input device\n",
334 input_dev->name);
335 return error;
336 }
337
338 i2c_set_clientdata(client, ts);
339
340 return 0;
341}
342
343static int __maybe_unused st1232_ts_suspend(struct device *dev)
344{
345 struct i2c_client *client = to_i2c_client(dev);
346 struct st1232_ts_data *ts = i2c_get_clientdata(client);
347
348 disable_irq(client->irq);
349
350 if (!device_may_wakeup(&client->dev))
351 st1232_ts_power(ts, false);
352
353 return 0;
354}
355
356static int __maybe_unused st1232_ts_resume(struct device *dev)
357{
358 struct i2c_client *client = to_i2c_client(dev);
359 struct st1232_ts_data *ts = i2c_get_clientdata(client);
360
361 if (!device_may_wakeup(&client->dev))
362 st1232_ts_power(ts, true);
363
364 enable_irq(client->irq);
365
366 return 0;
367}
368
369static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
370 st1232_ts_suspend, st1232_ts_resume);
371
372static const struct i2c_device_id st1232_ts_id[] = {
373 { ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
374 { ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
375 { }
376};
377MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
378
379static const struct of_device_id st1232_ts_dt_ids[] = {
380 { .compatible = "sitronix,st1232", .data = &st1232_chip_info },
381 { .compatible = "sitronix,st1633", .data = &st1633_chip_info },
382 { }
383};
384MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
385
386static struct i2c_driver st1232_ts_driver = {
387 .probe = st1232_ts_probe,
388 .id_table = st1232_ts_id,
389 .driver = {
390 .name = ST1232_TS_NAME,
391 .of_match_table = st1232_ts_dt_ids,
392 .pm = &st1232_ts_pm_ops,
393 },
394};
395
396module_i2c_driver(st1232_ts_driver);
397
398MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
399MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>");
400MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
401MODULE_LICENSE("GPL v2");
402
