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1// SPDX-License-Identifier: GPL-2.0-only
2
3#include <linux/bitfield.h>
4#include <linux/bits.h>
5#include <linux/delay.h>
6#include <linux/i2c.h>
7#include <linux/input.h>
8#include <linux/input/mt.h>
9#include <linux/input/touchscreen.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/property.h>
13#include <linux/regulator/consumer.h>
14
15#define IST30XX_REG_STATUS 0x20
16#define IST30XX_REG_CHIPID (0x40000000 | IST3038C_DIRECT_ACCESS)
17
18#define IST30XX_WHOAMI 0x30003000
19#define IST30XXA_WHOAMI 0x300a300a
20#define IST30XXB_WHOAMI 0x300b300b
21#define IST3038_WHOAMI 0x30383038
22
23#define IST3032C_WHOAMI 0x32c
24#define IST3038C_WHOAMI 0x38c
25#define IST3038H_WHOAMI 0x38d
26
27#define IST3038B_REG_CHIPID 0x30
28#define IST3038B_WHOAMI 0x30380b
29
30#define IST3038C_HIB_ACCESS (0x800B << 16)
31#define IST3038C_DIRECT_ACCESS BIT(31)
32#define IST3038C_REG_CHIPID (0x40001000 | IST3038C_DIRECT_ACCESS)
33#define IST3038C_REG_HIB_BASE 0x30000100
34#define IST3038C_REG_TOUCH_STATUS (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS)
35#define IST3038C_REG_TOUCH_COORD (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x8)
36#define IST3038C_REG_INTR_MESSAGE (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x4)
37#define IST3038C_CHIP_ON_DELAY_MS 60
38#define IST3038C_I2C_RETRY_COUNT 3
39#define IST3038C_MAX_FINGER_NUM 10
40#define IST3038C_X_MASK GENMASK(23, 12)
41#define IST3038C_Y_MASK GENMASK(11, 0)
42#define IST3038C_AREA_MASK GENMASK(27, 24)
43#define IST3038C_FINGER_COUNT_MASK GENMASK(15, 12)
44#define IST3038C_FINGER_STATUS_MASK GENMASK(9, 0)
45#define IST3032C_KEY_STATUS_MASK GENMASK(20, 16)
46
47struct imagis_properties {
48 unsigned int interrupt_msg_cmd;
49 unsigned int touch_coord_cmd;
50 unsigned int whoami_cmd;
51 unsigned int whoami_val;
52 bool protocol_b;
53 bool touch_keys_supported;
54};
55
56struct imagis_ts {
57 struct i2c_client *client;
58 const struct imagis_properties *tdata;
59 struct input_dev *input_dev;
60 struct touchscreen_properties prop;
61 struct regulator_bulk_data supplies[2];
62 u32 keycodes[5];
63 int num_keycodes;
64};
65
66static int imagis_i2c_read_reg(struct imagis_ts *ts,
67 unsigned int reg, u32 *data)
68{
69 __be32 ret_be;
70 __be32 reg_be = cpu_to_be32(reg);
71 struct i2c_msg msg[] = {
72 {
73 .addr = ts->client->addr,
74 .flags = 0,
75 .buf = (unsigned char *)&reg_be,
76 .len = sizeof(reg_be),
77 }, {
78 .addr = ts->client->addr,
79 .flags = I2C_M_RD,
80 .buf = (unsigned char *)&ret_be,
81 .len = sizeof(ret_be),
82 },
83 };
84 int ret, error;
85 int retry = IST3038C_I2C_RETRY_COUNT;
86
87 /* Retry in case the controller fails to respond */
88 do {
89 ret = i2c_transfer(ts->client->adapter, msg, ARRAY_SIZE(msg));
90 if (ret == ARRAY_SIZE(msg)) {
91 *data = be32_to_cpu(ret_be);
92 return 0;
93 }
94
95 error = ret < 0 ? ret : -EIO;
96 dev_err(&ts->client->dev,
97 "%s - i2c_transfer failed: %d (%d)\n",
98 __func__, error, ret);
99 } while (--retry);
100
101 return error;
102}
103
104static irqreturn_t imagis_interrupt(int irq, void *dev_id)
105{
106 struct imagis_ts *ts = dev_id;
107 u32 intr_message, finger_status;
108 unsigned int finger_count, finger_pressed, key_pressed;
109 int i;
110 int error;
111
112 error = imagis_i2c_read_reg(ts, ts->tdata->interrupt_msg_cmd, &intr_message);
113 if (error) {
114 dev_err(&ts->client->dev,
115 "failed to read the interrupt message: %d\n", error);
116 goto out;
117 }
118
119 finger_count = FIELD_GET(IST3038C_FINGER_COUNT_MASK, intr_message);
120 if (finger_count > IST3038C_MAX_FINGER_NUM) {
121 dev_err(&ts->client->dev,
122 "finger count %d is more than maximum supported\n",
123 finger_count);
124 goto out;
125 }
126
127 finger_pressed = FIELD_GET(IST3038C_FINGER_STATUS_MASK, intr_message);
128
129 for (i = 0; i < finger_count; i++) {
130 if (ts->tdata->protocol_b)
131 error = imagis_i2c_read_reg(ts,
132 ts->tdata->touch_coord_cmd + (i * 4),
133 &finger_status);
134 else
135 error = imagis_i2c_read_reg(ts,
136 ts->tdata->touch_coord_cmd, &finger_status);
137 if (error) {
138 dev_err(&ts->client->dev,
139 "failed to read coordinates for finger %d: %d\n",
140 i, error);
141 goto out;
142 }
143
144 input_mt_slot(ts->input_dev, i);
145 input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER,
146 finger_pressed & BIT(i));
147 touchscreen_report_pos(ts->input_dev, &ts->prop,
148 FIELD_GET(IST3038C_X_MASK, finger_status),
149 FIELD_GET(IST3038C_Y_MASK, finger_status),
150 true);
151 input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR,
152 FIELD_GET(IST3038C_AREA_MASK, finger_status));
153 }
154
155 key_pressed = FIELD_GET(IST3032C_KEY_STATUS_MASK, intr_message);
156
157 for (int i = 0; i < ts->num_keycodes; i++)
158 input_report_key(ts->input_dev, ts->keycodes[i],
159 key_pressed & BIT(i));
160
161 input_mt_sync_frame(ts->input_dev);
162 input_sync(ts->input_dev);
163
164out:
165 return IRQ_HANDLED;
166}
167
168static void imagis_power_off(void *_ts)
169{
170 struct imagis_ts *ts = _ts;
171
172 regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
173}
174
175static int imagis_power_on(struct imagis_ts *ts)
176{
177 int error;
178
179 error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
180 if (error)
181 return error;
182
183 msleep(IST3038C_CHIP_ON_DELAY_MS);
184
185 return 0;
186}
187
188static int imagis_start(struct imagis_ts *ts)
189{
190 int error;
191
192 error = imagis_power_on(ts);
193 if (error)
194 return error;
195
196 enable_irq(ts->client->irq);
197
198 return 0;
199}
200
201static int imagis_stop(struct imagis_ts *ts)
202{
203 disable_irq(ts->client->irq);
204
205 imagis_power_off(ts);
206
207 return 0;
208}
209
210static int imagis_input_open(struct input_dev *dev)
211{
212 struct imagis_ts *ts = input_get_drvdata(dev);
213
214 return imagis_start(ts);
215}
216
217static void imagis_input_close(struct input_dev *dev)
218{
219 struct imagis_ts *ts = input_get_drvdata(dev);
220
221 imagis_stop(ts);
222}
223
224static int imagis_init_input_dev(struct imagis_ts *ts)
225{
226 struct input_dev *input_dev;
227 int error;
228
229 input_dev = devm_input_allocate_device(&ts->client->dev);
230 if (!input_dev)
231 return -ENOMEM;
232
233 ts->input_dev = input_dev;
234
235 input_dev->name = "Imagis capacitive touchscreen";
236 input_dev->phys = "input/ts";
237 input_dev->id.bustype = BUS_I2C;
238 input_dev->open = imagis_input_open;
239 input_dev->close = imagis_input_close;
240
241 input_set_drvdata(input_dev, ts);
242
243 input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
244 input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
245 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 16, 0, 0);
246 if (ts->tdata->touch_keys_supported) {
247 ts->num_keycodes = of_property_read_variable_u32_array(
248 ts->client->dev.of_node, "linux,keycodes",
249 ts->keycodes, 0, ARRAY_SIZE(ts->keycodes));
250 if (ts->num_keycodes <= 0) {
251 ts->keycodes[0] = KEY_APPSELECT;
252 ts->keycodes[1] = KEY_BACK;
253 ts->num_keycodes = 2;
254 }
255
256 input_dev->keycodemax = ts->num_keycodes;
257 input_dev->keycodesize = sizeof(ts->keycodes[0]);
258 input_dev->keycode = ts->keycodes;
259 }
260
261 for (int i = 0; i < ts->num_keycodes; i++)
262 input_set_capability(input_dev, EV_KEY, ts->keycodes[i]);
263
264 touchscreen_parse_properties(input_dev, true, &ts->prop);
265 if (!ts->prop.max_x || !ts->prop.max_y) {
266 dev_err(&ts->client->dev,
267 "Touchscreen-size-x and/or touchscreen-size-y not set in dts\n");
268 return -EINVAL;
269 }
270
271 error = input_mt_init_slots(input_dev,
272 IST3038C_MAX_FINGER_NUM,
273 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
274 if (error) {
275 dev_err(&ts->client->dev,
276 "Failed to initialize MT slots: %d", error);
277 return error;
278 }
279
280 error = input_register_device(input_dev);
281 if (error) {
282 dev_err(&ts->client->dev,
283 "Failed to register input device: %d", error);
284 return error;
285 }
286
287 return 0;
288}
289
290static int imagis_init_regulators(struct imagis_ts *ts)
291{
292 struct i2c_client *client = ts->client;
293
294 ts->supplies[0].supply = "vdd";
295 ts->supplies[1].supply = "vddio";
296 return devm_regulator_bulk_get(&client->dev,
297 ARRAY_SIZE(ts->supplies),
298 ts->supplies);
299}
300
301static int imagis_probe(struct i2c_client *i2c)
302{
303 struct device *dev = &i2c->dev;
304 struct imagis_ts *ts;
305 int chip_id, error;
306
307 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
308 if (!ts)
309 return -ENOMEM;
310
311 ts->client = i2c;
312
313 ts->tdata = device_get_match_data(dev);
314 if (!ts->tdata) {
315 dev_err(dev, "missing chip data\n");
316 return -EINVAL;
317 }
318
319 error = imagis_init_regulators(ts);
320 if (error) {
321 dev_err(dev, "regulator init error: %d\n", error);
322 return error;
323 }
324
325 error = imagis_power_on(ts);
326 if (error) {
327 dev_err(dev, "failed to enable regulators: %d\n", error);
328 return error;
329 }
330
331 error = devm_add_action_or_reset(dev, imagis_power_off, ts);
332 if (error) {
333 dev_err(dev, "failed to install poweroff action: %d\n", error);
334 return error;
335 }
336
337 error = imagis_i2c_read_reg(ts, ts->tdata->whoami_cmd, &chip_id);
338 if (error) {
339 dev_err(dev, "chip ID read failure: %d\n", error);
340 return error;
341 }
342
343 if (chip_id != ts->tdata->whoami_val) {
344 dev_err(dev, "unknown chip ID: 0x%x\n", chip_id);
345 return -EINVAL;
346 }
347
348 error = devm_request_threaded_irq(dev, i2c->irq,
349 NULL, imagis_interrupt,
350 IRQF_ONESHOT | IRQF_NO_AUTOEN,
351 "imagis-touchscreen", ts);
352 if (error) {
353 dev_err(dev, "IRQ %d allocation failure: %d\n",
354 i2c->irq, error);
355 return error;
356 }
357
358 error = imagis_init_input_dev(ts);
359 if (error)
360 return error;
361
362 return 0;
363}
364
365static int imagis_suspend(struct device *dev)
366{
367 struct i2c_client *client = to_i2c_client(dev);
368 struct imagis_ts *ts = i2c_get_clientdata(client);
369 int error;
370
371 guard(mutex)(&ts->input_dev->mutex);
372
373 if (input_device_enabled(ts->input_dev)) {
374 error = imagis_stop(ts);
375 if (error)
376 return error;
377 }
378
379 return 0;
380}
381
382static int imagis_resume(struct device *dev)
383{
384 struct i2c_client *client = to_i2c_client(dev);
385 struct imagis_ts *ts = i2c_get_clientdata(client);
386 int error;
387
388 guard(mutex)(&ts->input_dev->mutex);
389
390 if (input_device_enabled(ts->input_dev)) {
391 error = imagis_start(ts);
392 if (error)
393 return error;
394 }
395
396 return 0;
397}
398
399static DEFINE_SIMPLE_DEV_PM_OPS(imagis_pm_ops, imagis_suspend, imagis_resume);
400
401#ifdef CONFIG_OF
402static const struct imagis_properties imagis_3032c_data = {
403 .interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
404 .touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
405 .whoami_cmd = IST3038C_REG_CHIPID,
406 .whoami_val = IST3032C_WHOAMI,
407 .touch_keys_supported = true,
408 .protocol_b = true,
409};
410
411static const struct imagis_properties imagis_3038_data = {
412 .interrupt_msg_cmd = IST30XX_REG_STATUS,
413 .touch_coord_cmd = IST30XX_REG_STATUS,
414 .whoami_cmd = IST30XX_REG_CHIPID,
415 .whoami_val = IST3038_WHOAMI,
416 .touch_keys_supported = true,
417};
418
419static const struct imagis_properties imagis_3038b_data = {
420 .interrupt_msg_cmd = IST30XX_REG_STATUS,
421 .touch_coord_cmd = IST30XX_REG_STATUS,
422 .whoami_cmd = IST3038B_REG_CHIPID,
423 .whoami_val = IST3038B_WHOAMI,
424};
425
426static const struct imagis_properties imagis_3038c_data = {
427 .interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
428 .touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
429 .whoami_cmd = IST3038C_REG_CHIPID,
430 .whoami_val = IST3038C_WHOAMI,
431 .protocol_b = true,
432};
433
434static const struct imagis_properties imagis_3038h_data = {
435 .interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
436 .touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
437 .whoami_cmd = IST3038C_REG_CHIPID,
438 .whoami_val = IST3038H_WHOAMI,
439};
440
441static const struct of_device_id imagis_of_match[] = {
442 { .compatible = "imagis,ist3032c", .data = &imagis_3032c_data },
443 { .compatible = "imagis,ist3038", .data = &imagis_3038_data },
444 { .compatible = "imagis,ist3038b", .data = &imagis_3038b_data },
445 { .compatible = "imagis,ist3038c", .data = &imagis_3038c_data },
446 { .compatible = "imagis,ist3038h", .data = &imagis_3038h_data },
447 { },
448};
449MODULE_DEVICE_TABLE(of, imagis_of_match);
450#endif
451
452static struct i2c_driver imagis_ts_driver = {
453 .driver = {
454 .name = "imagis-touchscreen",
455 .pm = pm_sleep_ptr(&imagis_pm_ops),
456 .of_match_table = of_match_ptr(imagis_of_match),
457 },
458 .probe = imagis_probe,
459};
460
461module_i2c_driver(imagis_ts_driver);
462
463MODULE_DESCRIPTION("Imagis IST3038C Touchscreen Driver");
464MODULE_AUTHOR("Markuss Broks <[email protected]>");
465MODULE_LICENSE("GPL");