1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ST1232 Touchscreen Controller Driver
4  *
5  * Copyright (C) 2010 Renesas Solutions Corp.
6  *	Tony SIM <chinyeow.sim.xt@renesas.com>
7  *
8  * Using code from:
9  *  - android.git.kernel.org: projects/kernel/common.git: synaptics_i2c_rmi.c
10  *	Copyright (C) 2007 Google, Inc.
11  */
12 
13 #include <linux/delay.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/i2c.h>
16 #include <linux/input.h>
17 #include <linux/interrupt.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/pm_qos.h>
21 #include <linux/slab.h>
22 #include <linux/types.h>
23 #include <linux/input/touchscreen.h>
24 
25 #define ST1232_TS_NAME	"st1232-ts"
26 #define ST1633_TS_NAME	"st1633-ts"
27 
28 struct st1232_ts_finger {
29 	u16 x;
30 	u16 y;
31 	u8 t;
32 	bool is_valid;
33 };
34 
35 struct st_chip_info {
36 	bool	have_z;
37 	u16	max_x;
38 	u16	max_y;
39 	u16	max_area;
40 	u16	max_fingers;
41 	u8	start_reg;
42 };
43 
44 struct st1232_ts_data {
45 	struct i2c_client *client;
46 	struct input_dev *input_dev;
47 	struct touchscreen_properties prop;
48 	struct dev_pm_qos_request low_latency_req;
49 	struct gpio_desc *reset_gpio;
50 	const struct st_chip_info *chip_info;
51 	int read_buf_len;
52 	u8 *read_buf;
53 	struct st1232_ts_finger *finger;
54 };
55 
56 static int st1232_ts_read_data(struct st1232_ts_data *ts)
57 {
58 	struct st1232_ts_finger *finger = ts->finger;
59 	struct i2c_client *client = ts->client;
60 	struct i2c_msg msg[2];
61 	int error;
62 	int i, y;
63 	u8 start_reg = ts->chip_info->start_reg;
64 	u8 *buf = ts->read_buf;
65 
66 	/* read touchscreen data */
67 	msg[0].addr = client->addr;
68 	msg[0].flags = 0;
69 	msg[0].len = 1;
70 	msg[0].buf = &start_reg;
71 
72 	msg[1].addr = ts->client->addr;
73 	msg[1].flags = I2C_M_RD;
74 	msg[1].len = ts->read_buf_len;
75 	msg[1].buf = buf;
76 
77 	error = i2c_transfer(client->adapter, msg, 2);
78 	if (error < 0)
79 		return error;
80 
81 	for (i = 0, y = 0; i < ts->chip_info->max_fingers; i++, y += 3) {
82 		finger[i].is_valid = buf[i + y] >> 7;
83 		if (finger[i].is_valid) {
84 			finger[i].x = ((buf[i + y] & 0x0070) << 4) |
85 					buf[i + y + 1];
86 			finger[i].y = ((buf[i + y] & 0x0007) << 8) |
87 					buf[i + y + 2];
88 
89 			/* st1232 includes a z-axis / touch strength */
90 			if (ts->chip_info->have_z)
91 				finger[i].t = buf[i + 6];
92 		}
93 	}
94 
95 	return 0;
96 }
97 
98 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
99 {
100 	struct st1232_ts_data *ts = dev_id;
101 	struct st1232_ts_finger *finger = ts->finger;
102 	struct input_dev *input_dev = ts->input_dev;
103 	int count = 0;
104 	int i, ret;
105 
106 	ret = st1232_ts_read_data(ts);
107 	if (ret < 0)
108 		goto end;
109 
110 	/* multi touch protocol */
111 	for (i = 0; i < ts->chip_info->max_fingers; i++) {
112 		if (!finger[i].is_valid)
113 			continue;
114 
115 		if (ts->chip_info->have_z)
116 			input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR,
117 					 finger[i].t);
118 
119 		touchscreen_report_pos(input_dev, &ts->prop,
120 					finger[i].x, finger[i].y, true);
121 		input_mt_sync(input_dev);
122 		count++;
123 	}
124 
125 	/* SYN_MT_REPORT only if no contact */
126 	if (!count) {
127 		input_mt_sync(input_dev);
128 		if (ts->low_latency_req.dev) {
129 			dev_pm_qos_remove_request(&ts->low_latency_req);
130 			ts->low_latency_req.dev = NULL;
131 		}
132 	} else if (!ts->low_latency_req.dev) {
133 		/* First contact, request 100 us latency. */
134 		dev_pm_qos_add_ancestor_request(&ts->client->dev,
135 						&ts->low_latency_req,
136 						DEV_PM_QOS_RESUME_LATENCY, 100);
137 	}
138 
139 	/* SYN_REPORT */
140 	input_sync(input_dev);
141 
142 end:
143 	return IRQ_HANDLED;
144 }
145 
146 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
147 {
148 	if (ts->reset_gpio)
149 		gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
150 }
151 
152 static const struct st_chip_info st1232_chip_info = {
153 	.have_z		= true,
154 	.max_x		= 0x31f, /* 800 - 1 */
155 	.max_y		= 0x1df, /* 480 -1 */
156 	.max_area	= 0xff,
157 	.max_fingers	= 2,
158 	.start_reg	= 0x12,
159 };
160 
161 static const struct st_chip_info st1633_chip_info = {
162 	.have_z		= false,
163 	.max_x		= 0x13f, /* 320 - 1 */
164 	.max_y		= 0x1df, /* 480 -1 */
165 	.max_area	= 0x00,
166 	.max_fingers	= 5,
167 	.start_reg	= 0x12,
168 };
169 
170 static int st1232_ts_probe(struct i2c_client *client,
171 			   const struct i2c_device_id *id)
172 {
173 	const struct st_chip_info *match;
174 	struct st1232_ts_data *ts;
175 	struct st1232_ts_finger *finger;
176 	struct input_dev *input_dev;
177 	int error;
178 
179 	match = device_get_match_data(&client->dev);
180 	if (!match && id)
181 		match = (const void *)id->driver_data;
182 	if (!match) {
183 		dev_err(&client->dev, "unknown device model\n");
184 		return -ENODEV;
185 	}
186 
187 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
188 		dev_err(&client->dev, "need I2C_FUNC_I2C\n");
189 		return -EIO;
190 	}
191 
192 	if (!client->irq) {
193 		dev_err(&client->dev, "no IRQ?\n");
194 		return -EINVAL;
195 	}
196 
197 	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
198 	if (!ts)
199 		return -ENOMEM;
200 
201 	ts->chip_info = match;
202 	ts->finger = devm_kcalloc(&client->dev,
203 				  ts->chip_info->max_fingers, sizeof(*finger),
204 				  GFP_KERNEL);
205 	if (!ts->finger)
206 		return -ENOMEM;
207 
208 	/* allocate a buffer according to the number of registers to read */
209 	ts->read_buf_len = ts->chip_info->max_fingers * 4;
210 	ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
211 	if (!ts->read_buf)
212 		return -ENOMEM;
213 
214 	input_dev = devm_input_allocate_device(&client->dev);
215 	if (!input_dev)
216 		return -ENOMEM;
217 
218 	ts->client = client;
219 	ts->input_dev = input_dev;
220 
221 	ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
222 						 GPIOD_OUT_HIGH);
223 	if (IS_ERR(ts->reset_gpio)) {
224 		error = PTR_ERR(ts->reset_gpio);
225 		dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
226 			error);
227 		return error;
228 	}
229 
230 	st1232_ts_power(ts, true);
231 
232 	input_dev->name = "st1232-touchscreen";
233 	input_dev->id.bustype = BUS_I2C;
234 	input_dev->dev.parent = &client->dev;
235 
236 	__set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
237 	__set_bit(EV_SYN, input_dev->evbit);
238 	__set_bit(EV_KEY, input_dev->evbit);
239 	__set_bit(EV_ABS, input_dev->evbit);
240 
241 	if (ts->chip_info->have_z)
242 		input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
243 				     ts->chip_info->max_area, 0, 0);
244 
245 	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
246 			     0, ts->chip_info->max_x, 0, 0);
247 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
248 			     0, ts->chip_info->max_y, 0, 0);
249 
250 	touchscreen_parse_properties(input_dev, true, &ts->prop);
251 
252 	error = devm_request_threaded_irq(&client->dev, client->irq,
253 					  NULL, st1232_ts_irq_handler,
254 					  IRQF_ONESHOT,
255 					  client->name, ts);
256 	if (error) {
257 		dev_err(&client->dev, "Failed to register interrupt\n");
258 		return error;
259 	}
260 
261 	error = input_register_device(ts->input_dev);
262 	if (error) {
263 		dev_err(&client->dev, "Unable to register %s input device\n",
264 			input_dev->name);
265 		return error;
266 	}
267 
268 	i2c_set_clientdata(client, ts);
269 	device_init_wakeup(&client->dev, 1);
270 
271 	return 0;
272 }
273 
274 static int st1232_ts_remove(struct i2c_client *client)
275 {
276 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
277 
278 	st1232_ts_power(ts, false);
279 
280 	return 0;
281 }
282 
283 static int __maybe_unused st1232_ts_suspend(struct device *dev)
284 {
285 	struct i2c_client *client = to_i2c_client(dev);
286 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
287 
288 	if (device_may_wakeup(&client->dev)) {
289 		enable_irq_wake(client->irq);
290 	} else {
291 		disable_irq(client->irq);
292 		st1232_ts_power(ts, false);
293 	}
294 
295 	return 0;
296 }
297 
298 static int __maybe_unused st1232_ts_resume(struct device *dev)
299 {
300 	struct i2c_client *client = to_i2c_client(dev);
301 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
302 
303 	if (device_may_wakeup(&client->dev)) {
304 		disable_irq_wake(client->irq);
305 	} else {
306 		st1232_ts_power(ts, true);
307 		enable_irq(client->irq);
308 	}
309 
310 	return 0;
311 }
312 
313 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
314 			 st1232_ts_suspend, st1232_ts_resume);
315 
316 static const struct i2c_device_id st1232_ts_id[] = {
317 	{ ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
318 	{ ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
319 	{ }
320 };
321 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
322 
323 static const struct of_device_id st1232_ts_dt_ids[] = {
324 	{ .compatible = "sitronix,st1232", .data = &st1232_chip_info },
325 	{ .compatible = "sitronix,st1633", .data = &st1633_chip_info },
326 	{ }
327 };
328 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
329 
330 static struct i2c_driver st1232_ts_driver = {
331 	.probe		= st1232_ts_probe,
332 	.remove		= st1232_ts_remove,
333 	.id_table	= st1232_ts_id,
334 	.driver = {
335 		.name	= ST1232_TS_NAME,
336 		.of_match_table = st1232_ts_dt_ids,
337 		.pm	= &st1232_ts_pm_ops,
338 	},
339 };
340 
341 module_i2c_driver(st1232_ts_driver);
342 
343 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
344 MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>");
345 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
346 MODULE_LICENSE("GPL v2");
347