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 IST3032C_WHOAMI			0x32c
16
17#define IST3038B_REG_STATUS		0x20
18#define IST3038B_REG_CHIPID		0x30
19#define IST3038B_WHOAMI			0x30380b
20
21#define IST3038C_HIB_ACCESS		(0x800B << 16)
22#define IST3038C_DIRECT_ACCESS		BIT(31)
23#define IST3038C_REG_CHIPID		(0x40001000 | IST3038C_DIRECT_ACCESS)
24#define IST3038C_REG_HIB_BASE		0x30000100
25#define IST3038C_REG_TOUCH_STATUS	(IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS)
26#define IST3038C_REG_TOUCH_COORD	(IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x8)
27#define IST3038C_REG_INTR_MESSAGE	(IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x4)
28#define IST3038C_WHOAMI			0x38c
29#define IST3038C_CHIP_ON_DELAY_MS	60
30#define IST3038C_I2C_RETRY_COUNT	3
31#define IST3038C_MAX_FINGER_NUM		10
32#define IST3038C_X_MASK			GENMASK(23, 12)
33#define IST3038C_Y_MASK			GENMASK(11, 0)
34#define IST3038C_AREA_MASK		GENMASK(27, 24)
35#define IST3038C_FINGER_COUNT_MASK	GENMASK(15, 12)
36#define IST3038C_FINGER_STATUS_MASK	GENMASK(9, 0)
37#define IST3032C_KEY_STATUS_MASK	GENMASK(20, 16)
38
39struct imagis_properties {
40	unsigned int interrupt_msg_cmd;
41	unsigned int touch_coord_cmd;
42	unsigned int whoami_cmd;
43	unsigned int whoami_val;
44	bool protocol_b;
45	bool touch_keys_supported;
46};
47
48struct imagis_ts {
49	struct i2c_client *client;
50	const struct imagis_properties *tdata;
51	struct input_dev *input_dev;
52	struct touchscreen_properties prop;
53	struct regulator_bulk_data supplies[2];
54	u32 keycodes[5];
55	int num_keycodes;
56};
57
58static int imagis_i2c_read_reg(struct imagis_ts *ts,
59			       unsigned int reg, u32 *data)
60{
61	__be32 ret_be;
62	__be32 reg_be = cpu_to_be32(reg);
63	struct i2c_msg msg[] = {
64		{
65			.addr = ts->client->addr,
66			.flags = 0,
67			.buf = (unsigned char *)&reg_be,
68			.len = sizeof(reg_be),
69		}, {
70			.addr = ts->client->addr,
71			.flags = I2C_M_RD,
72			.buf = (unsigned char *)&ret_be,
73			.len = sizeof(ret_be),
74		},
75	};
76	int ret, error;
77	int retry = IST3038C_I2C_RETRY_COUNT;
78
79	/* Retry in case the controller fails to respond */
80	do {
81		ret = i2c_transfer(ts->client->adapter, msg, ARRAY_SIZE(msg));
82		if (ret == ARRAY_SIZE(msg)) {
83			*data = be32_to_cpu(ret_be);
84			return 0;
85		}
86
87		error = ret < 0 ? ret : -EIO;
88		dev_err(&ts->client->dev,
89			"%s - i2c_transfer failed: %d (%d)\n",
90			__func__, error, ret);
91	} while (--retry);
92
93	return error;
94}
95
96static irqreturn_t imagis_interrupt(int irq, void *dev_id)
97{
98	struct imagis_ts *ts = dev_id;
99	u32 intr_message, finger_status;
100	unsigned int finger_count, finger_pressed, key_pressed;
101	int i;
102	int error;
103
104	error = imagis_i2c_read_reg(ts, ts->tdata->interrupt_msg_cmd, &intr_message);
105	if (error) {
106		dev_err(&ts->client->dev,
107			"failed to read the interrupt message: %d\n", error);
108		goto out;
109	}
110
111	finger_count = FIELD_GET(IST3038C_FINGER_COUNT_MASK, intr_message);
112	if (finger_count > IST3038C_MAX_FINGER_NUM) {
113		dev_err(&ts->client->dev,
114			"finger count %d is more than maximum supported\n",
115			finger_count);
116		goto out;
117	}
118
119	finger_pressed = FIELD_GET(IST3038C_FINGER_STATUS_MASK, intr_message);
120
121	for (i = 0; i < finger_count; i++) {
122		if (ts->tdata->protocol_b)
123			error = imagis_i2c_read_reg(ts,
124						    ts->tdata->touch_coord_cmd, &finger_status);
125		else
126			error = imagis_i2c_read_reg(ts,
127						    ts->tdata->touch_coord_cmd + (i * 4),
128						    &finger_status);
129		if (error) {
130			dev_err(&ts->client->dev,
131				"failed to read coordinates for finger %d: %d\n",
132				i, error);
133			goto out;
134		}
135
136		input_mt_slot(ts->input_dev, i);
137		input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER,
138					   finger_pressed & BIT(i));
139		touchscreen_report_pos(ts->input_dev, &ts->prop,
140				       FIELD_GET(IST3038C_X_MASK, finger_status),
141				       FIELD_GET(IST3038C_Y_MASK, finger_status),
142				       true);
143		input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR,
144				 FIELD_GET(IST3038C_AREA_MASK, finger_status));
145	}
146
147	key_pressed = FIELD_GET(IST3032C_KEY_STATUS_MASK, intr_message);
148
149	for (int i = 0; i < ts->num_keycodes; i++)
150		input_report_key(ts->input_dev, ts->keycodes[i],
151				 key_pressed & BIT(i));
152
153	input_mt_sync_frame(ts->input_dev);
154	input_sync(ts->input_dev);
155
156out:
157	return IRQ_HANDLED;
158}
159
160static void imagis_power_off(void *_ts)
161{
162	struct imagis_ts *ts = _ts;
163
164	regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
165}
166
167static int imagis_power_on(struct imagis_ts *ts)
168{
169	int error;
170
171	error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
172	if (error)
173		return error;
174
175	msleep(IST3038C_CHIP_ON_DELAY_MS);
176
177	return 0;
178}
179
180static int imagis_start(struct imagis_ts *ts)
181{
182	int error;
183
184	error = imagis_power_on(ts);
185	if (error)
186		return error;
187
188	enable_irq(ts->client->irq);
189
190	return 0;
191}
192
193static int imagis_stop(struct imagis_ts *ts)
194{
195	disable_irq(ts->client->irq);
196
197	imagis_power_off(ts);
198
199	return 0;
200}
201
202static int imagis_input_open(struct input_dev *dev)
203{
204	struct imagis_ts *ts = input_get_drvdata(dev);
205
206	return imagis_start(ts);
207}
208
209static void imagis_input_close(struct input_dev *dev)
210{
211	struct imagis_ts *ts = input_get_drvdata(dev);
212
213	imagis_stop(ts);
214}
215
216static int imagis_init_input_dev(struct imagis_ts *ts)
217{
218	struct input_dev *input_dev;
219	int error;
220
221	input_dev = devm_input_allocate_device(&ts->client->dev);
222	if (!input_dev)
223		return -ENOMEM;
224
225	ts->input_dev = input_dev;
226
227	input_dev->name = "Imagis capacitive touchscreen";
228	input_dev->phys = "input/ts";
229	input_dev->id.bustype = BUS_I2C;
230	input_dev->open = imagis_input_open;
231	input_dev->close = imagis_input_close;
232
233	input_set_drvdata(input_dev, ts);
234
235	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
236	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
237	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 16, 0, 0);
238	if (ts->tdata->touch_keys_supported) {
239		ts->num_keycodes = of_property_read_variable_u32_array(
240				ts->client->dev.of_node, "linux,keycodes",
241				ts->keycodes, 0, ARRAY_SIZE(ts->keycodes));
242		if (ts->num_keycodes <= 0) {
243			ts->keycodes[0] = KEY_APPSELECT;
244			ts->keycodes[1] = KEY_BACK;
245			ts->num_keycodes = 2;
246		}
247
248		input_dev->keycodemax = ts->num_keycodes;
249		input_dev->keycodesize = sizeof(ts->keycodes[0]);
250		input_dev->keycode = ts->keycodes;
251	}
252
253	for (int i = 0; i < ts->num_keycodes; i++)
254		input_set_capability(input_dev, EV_KEY, ts->keycodes[i]);
255
256	touchscreen_parse_properties(input_dev, true, &ts->prop);
257	if (!ts->prop.max_x || !ts->prop.max_y) {
258		dev_err(&ts->client->dev,
259			"Touchscreen-size-x and/or touchscreen-size-y not set in dts\n");
260		return -EINVAL;
261	}
262
263	error = input_mt_init_slots(input_dev,
264				    IST3038C_MAX_FINGER_NUM,
265				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
266	if (error) {
267		dev_err(&ts->client->dev,
268			"Failed to initialize MT slots: %d", error);
269		return error;
270	}
271
272	error = input_register_device(input_dev);
273	if (error) {
274		dev_err(&ts->client->dev,
275			"Failed to register input device: %d", error);
276		return error;
277	}
278
279	return 0;
280}
281
282static int imagis_init_regulators(struct imagis_ts *ts)
283{
284	struct i2c_client *client = ts->client;
285
286	ts->supplies[0].supply = "vdd";
287	ts->supplies[1].supply = "vddio";
288	return devm_regulator_bulk_get(&client->dev,
289				       ARRAY_SIZE(ts->supplies),
290				       ts->supplies);
291}
292
293static int imagis_probe(struct i2c_client *i2c)
294{
295	struct device *dev = &i2c->dev;
296	struct imagis_ts *ts;
297	int chip_id, error;
298
299	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
300	if (!ts)
301		return -ENOMEM;
302
303	ts->client = i2c;
304
305	ts->tdata = device_get_match_data(dev);
306	if (!ts->tdata) {
307		dev_err(dev, "missing chip data\n");
308		return -EINVAL;
309	}
310
311	error = imagis_init_regulators(ts);
312	if (error) {
313		dev_err(dev, "regulator init error: %d\n", error);
314		return error;
315	}
316
317	error = imagis_power_on(ts);
318	if (error) {
319		dev_err(dev, "failed to enable regulators: %d\n", error);
320		return error;
321	}
322
323	error = devm_add_action_or_reset(dev, imagis_power_off, ts);
324	if (error) {
325		dev_err(dev, "failed to install poweroff action: %d\n", error);
326		return error;
327	}
328
329	error = imagis_i2c_read_reg(ts, ts->tdata->whoami_cmd, &chip_id);
330	if (error) {
331		dev_err(dev, "chip ID read failure: %d\n", error);
332		return error;
333	}
334
335	if (chip_id != ts->tdata->whoami_val) {
336		dev_err(dev, "unknown chip ID: 0x%x\n", chip_id);
337		return -EINVAL;
338	}
339
340	error = devm_request_threaded_irq(dev, i2c->irq,
341					  NULL, imagis_interrupt,
342					  IRQF_ONESHOT | IRQF_NO_AUTOEN,
343					  "imagis-touchscreen", ts);
344	if (error) {
345		dev_err(dev, "IRQ %d allocation failure: %d\n",
346			i2c->irq, error);
347		return error;
348	}
349
350	error = imagis_init_input_dev(ts);
351	if (error)
352		return error;
353
354	return 0;
355}
356
357static int imagis_suspend(struct device *dev)
358{
359	struct i2c_client *client = to_i2c_client(dev);
360	struct imagis_ts *ts = i2c_get_clientdata(client);
361	int retval = 0;
362
363	mutex_lock(&ts->input_dev->mutex);
364
365	if (input_device_enabled(ts->input_dev))
366		retval = imagis_stop(ts);
367
368	mutex_unlock(&ts->input_dev->mutex);
369
370	return retval;
371}
372
373static int imagis_resume(struct device *dev)
374{
375	struct i2c_client *client = to_i2c_client(dev);
376	struct imagis_ts *ts = i2c_get_clientdata(client);
377	int retval = 0;
378
379	mutex_lock(&ts->input_dev->mutex);
380
381	if (input_device_enabled(ts->input_dev))
382		retval = imagis_start(ts);
383
384	mutex_unlock(&ts->input_dev->mutex);
385
386	return retval;
387}
388
389static DEFINE_SIMPLE_DEV_PM_OPS(imagis_pm_ops, imagis_suspend, imagis_resume);
390
391static const struct imagis_properties imagis_3032c_data = {
392	.interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
393	.touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
394	.whoami_cmd = IST3038C_REG_CHIPID,
395	.whoami_val = IST3032C_WHOAMI,
396	.touch_keys_supported = true,
397};
398
399static const struct imagis_properties imagis_3038b_data = {
400	.interrupt_msg_cmd = IST3038B_REG_STATUS,
401	.touch_coord_cmd = IST3038B_REG_STATUS,
402	.whoami_cmd = IST3038B_REG_CHIPID,
403	.whoami_val = IST3038B_WHOAMI,
404	.protocol_b = true,
405};
406
407static const struct imagis_properties imagis_3038c_data = {
408	.interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
409	.touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
410	.whoami_cmd = IST3038C_REG_CHIPID,
411	.whoami_val = IST3038C_WHOAMI,
412};
413
414#ifdef CONFIG_OF
415static const struct of_device_id imagis_of_match[] = {
416	{ .compatible = "imagis,ist3032c", .data = &imagis_3032c_data },
417	{ .compatible = "imagis,ist3038b", .data = &imagis_3038b_data },
418	{ .compatible = "imagis,ist3038c", .data = &imagis_3038c_data },
419	{ },
420};
421MODULE_DEVICE_TABLE(of, imagis_of_match);
422#endif
423
424static struct i2c_driver imagis_ts_driver = {
425	.driver = {
426		.name = "imagis-touchscreen",
427		.pm = pm_sleep_ptr(&imagis_pm_ops),
428		.of_match_table = of_match_ptr(imagis_of_match),
429	},
430	.probe = imagis_probe,
431};
432
433module_i2c_driver(imagis_ts_driver);
434
435MODULE_DESCRIPTION("Imagis IST3038C Touchscreen Driver");
436MODULE_AUTHOR("Markuss Broks <markuss.broks@gmail.com>");
437MODULE_LICENSE("GPL");
438