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