1 #include <linux/module.h>
2 #include <linux/i2c.h>
3 #include <linux/interrupt.h>
4 #include <linux/slab.h>
5 #include <linux/input.h>
6 #include <linux/input/mt.h>
7 #include <linux/input/touchscreen.h>
8 #include <linux/delay.h>
9 #include <linux/workqueue.h>
10 #include <linux/gpio/consumer.h>
11 #include <linux/of_device.h>
12 #include <asm/unaligned.h>
13 
14 #define ILI210X_TOUCHES		2
15 #define ILI251X_TOUCHES		10
16 #define DEFAULT_POLL_PERIOD	20
17 
18 /* Touchscreen commands */
19 #define REG_TOUCHDATA		0x10
20 #define REG_PANEL_INFO		0x20
21 #define REG_FIRMWARE_VERSION	0x40
22 #define REG_CALIBRATE		0xcc
23 
24 struct firmware_version {
25 	u8 id;
26 	u8 major;
27 	u8 minor;
28 } __packed;
29 
30 enum ili2xxx_model {
31 	MODEL_ILI210X,
32 	MODEL_ILI251X,
33 };
34 
35 struct ili210x {
36 	struct i2c_client *client;
37 	struct input_dev *input;
38 	unsigned int poll_period;
39 	struct delayed_work dwork;
40 	struct gpio_desc *reset_gpio;
41 	struct touchscreen_properties prop;
42 	enum ili2xxx_model model;
43 	unsigned int max_touches;
44 };
45 
46 static int ili210x_read_reg(struct i2c_client *client, u8 reg, void *buf,
47 			    size_t len)
48 {
49 	struct ili210x *priv = i2c_get_clientdata(client);
50 	struct i2c_msg msg[2] = {
51 		{
52 			.addr	= client->addr,
53 			.flags	= 0,
54 			.len	= 1,
55 			.buf	= &reg,
56 		},
57 		{
58 			.addr	= client->addr,
59 			.flags	= I2C_M_RD,
60 			.len	= len,
61 			.buf	= buf,
62 		}
63 	};
64 
65 	if (priv->model == MODEL_ILI251X) {
66 		if (i2c_transfer(client->adapter, msg, 1) != 1) {
67 			dev_err(&client->dev, "i2c transfer failed\n");
68 			return -EIO;
69 		}
70 
71 		usleep_range(5000, 5500);
72 
73 		if (i2c_transfer(client->adapter, msg + 1, 1) != 1) {
74 			dev_err(&client->dev, "i2c transfer failed\n");
75 			return -EIO;
76 		}
77 	} else {
78 		if (i2c_transfer(client->adapter, msg, 2) != 2) {
79 			dev_err(&client->dev, "i2c transfer failed\n");
80 			return -EIO;
81 		}
82 	}
83 
84 	return 0;
85 }
86 
87 static int ili210x_read(struct i2c_client *client, void *buf, size_t len)
88 {
89 	struct i2c_msg msg = {
90 		.addr	= client->addr,
91 		.flags	= I2C_M_RD,
92 		.len	= len,
93 		.buf	= buf,
94 	};
95 
96 	if (i2c_transfer(client->adapter, &msg, 1) != 1) {
97 		dev_err(&client->dev, "i2c transfer failed\n");
98 		return -EIO;
99 	}
100 
101 	return 0;
102 }
103 
104 static bool ili210x_touchdata_to_coords(struct ili210x *priv, u8 *touchdata,
105 					unsigned int finger,
106 					unsigned int *x, unsigned int *y)
107 {
108 	if (finger >= ILI210X_TOUCHES)
109 		return false;
110 
111 	if (touchdata[0] & BIT(finger))
112 		return false;
113 
114 	*x = get_unaligned_be16(touchdata + 1 + (finger * 4) + 0);
115 	*y = get_unaligned_be16(touchdata + 1 + (finger * 4) + 2);
116 
117 	return true;
118 }
119 
120 static bool ili251x_touchdata_to_coords(struct ili210x *priv, u8 *touchdata,
121 					unsigned int finger,
122 					unsigned int *x, unsigned int *y)
123 {
124 	if (finger >= ILI251X_TOUCHES)
125 		return false;
126 
127 	*x = get_unaligned_be16(touchdata + 1 + (finger * 5) + 0);
128 	if (!(*x & BIT(15)))	/* Touch indication */
129 		return false;
130 
131 	*x &= 0x3fff;
132 	*y = get_unaligned_be16(touchdata + 1 + (finger * 5) + 2);
133 
134 	return true;
135 }
136 
137 static bool ili210x_report_events(struct ili210x *priv, u8 *touchdata)
138 {
139 	struct input_dev *input = priv->input;
140 	int i;
141 	bool contact = false, touch = false;
142 	unsigned int x = 0, y = 0;
143 
144 	for (i = 0; i < priv->max_touches; i++) {
145 		if (priv->model == MODEL_ILI210X) {
146 			touch = ili210x_touchdata_to_coords(priv, touchdata,
147 							    i, &x, &y);
148 		} else if (priv->model == MODEL_ILI251X) {
149 			touch = ili251x_touchdata_to_coords(priv, touchdata,
150 							    i, &x, &y);
151 			if (touch)
152 				contact = true;
153 		}
154 
155 		input_mt_slot(input, i);
156 		input_mt_report_slot_state(input, MT_TOOL_FINGER, touch);
157 		if (!touch)
158 			continue;
159 		touchscreen_report_pos(input, &priv->prop, x, y,
160 				       true);
161 	}
162 
163 	input_mt_report_pointer_emulation(input, false);
164 	input_sync(input);
165 
166 	if (priv->model == MODEL_ILI210X)
167 		contact = touchdata[0] & 0xf3;
168 
169 	return contact;
170 }
171 
172 static void ili210x_work(struct work_struct *work)
173 {
174 	struct ili210x *priv = container_of(work, struct ili210x,
175 					    dwork.work);
176 	struct i2c_client *client = priv->client;
177 	u8 touchdata[64] = { 0 };
178 	bool touch;
179 	int error = -EINVAL;
180 
181 	if (priv->model == MODEL_ILI210X) {
182 		error = ili210x_read_reg(client, REG_TOUCHDATA,
183 					 touchdata, sizeof(touchdata));
184 	} else if (priv->model == MODEL_ILI251X) {
185 		error = ili210x_read_reg(client, REG_TOUCHDATA,
186 					 touchdata, 31);
187 		if (!error && touchdata[0] == 2)
188 			error = ili210x_read(client, &touchdata[31], 20);
189 	}
190 
191 	if (error) {
192 		dev_err(&client->dev,
193 			"Unable to get touchdata, err = %d\n", error);
194 		return;
195 	}
196 
197 	touch = ili210x_report_events(priv, touchdata);
198 
199 	if (touch)
200 		schedule_delayed_work(&priv->dwork,
201 				      msecs_to_jiffies(priv->poll_period));
202 }
203 
204 static irqreturn_t ili210x_irq(int irq, void *irq_data)
205 {
206 	struct ili210x *priv = irq_data;
207 
208 	schedule_delayed_work(&priv->dwork, 0);
209 
210 	return IRQ_HANDLED;
211 }
212 
213 static ssize_t ili210x_calibrate(struct device *dev,
214 				 struct device_attribute *attr,
215 				 const char *buf, size_t count)
216 {
217 	struct i2c_client *client = to_i2c_client(dev);
218 	struct ili210x *priv = i2c_get_clientdata(client);
219 	unsigned long calibrate;
220 	int rc;
221 	u8 cmd = REG_CALIBRATE;
222 
223 	if (kstrtoul(buf, 10, &calibrate))
224 		return -EINVAL;
225 
226 	if (calibrate > 1)
227 		return -EINVAL;
228 
229 	if (calibrate) {
230 		rc = i2c_master_send(priv->client, &cmd, sizeof(cmd));
231 		if (rc != sizeof(cmd))
232 			return -EIO;
233 	}
234 
235 	return count;
236 }
237 static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
238 
239 static struct attribute *ili210x_attributes[] = {
240 	&dev_attr_calibrate.attr,
241 	NULL,
242 };
243 
244 static const struct attribute_group ili210x_attr_group = {
245 	.attrs = ili210x_attributes,
246 };
247 
248 static void ili210x_power_down(void *data)
249 {
250 	struct gpio_desc *reset_gpio = data;
251 
252 	gpiod_set_value_cansleep(reset_gpio, 1);
253 }
254 
255 static void ili210x_cancel_work(void *data)
256 {
257 	struct ili210x *priv = data;
258 
259 	cancel_delayed_work_sync(&priv->dwork);
260 }
261 
262 static int ili210x_i2c_probe(struct i2c_client *client,
263 				       const struct i2c_device_id *id)
264 {
265 	struct device *dev = &client->dev;
266 	struct ili210x *priv;
267 	struct gpio_desc *reset_gpio;
268 	struct input_dev *input;
269 	struct firmware_version firmware;
270 	enum ili2xxx_model model;
271 	int error;
272 
273 	model = (enum ili2xxx_model)id->driver_data;
274 
275 	dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
276 
277 	if (client->irq <= 0) {
278 		dev_err(dev, "No IRQ!\n");
279 		return -EINVAL;
280 	}
281 
282 	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
283 	if (IS_ERR(reset_gpio))
284 		return PTR_ERR(reset_gpio);
285 
286 	if (reset_gpio) {
287 		error = devm_add_action_or_reset(dev, ili210x_power_down,
288 						 reset_gpio);
289 		if (error)
290 			return error;
291 
292 		usleep_range(50, 100);
293 		gpiod_set_value_cansleep(reset_gpio, 0);
294 		msleep(100);
295 	}
296 
297 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
298 	if (!priv)
299 		return -ENOMEM;
300 
301 	input = devm_input_allocate_device(dev);
302 	if (!input)
303 		return -ENOMEM;
304 
305 	priv->client = client;
306 	priv->input = input;
307 	priv->poll_period = DEFAULT_POLL_PERIOD;
308 	INIT_DELAYED_WORK(&priv->dwork, ili210x_work);
309 	priv->reset_gpio = reset_gpio;
310 	priv->model = model;
311 	if (model == MODEL_ILI210X)
312 		priv->max_touches = ILI210X_TOUCHES;
313 	if (model == MODEL_ILI251X)
314 		priv->max_touches = ILI251X_TOUCHES;
315 
316 	i2c_set_clientdata(client, priv);
317 
318 	/* Get firmware version */
319 	error = ili210x_read_reg(client, REG_FIRMWARE_VERSION,
320 				 &firmware, sizeof(firmware));
321 	if (error) {
322 		dev_err(dev, "Failed to get firmware version, err: %d\n",
323 			error);
324 		return error;
325 	}
326 
327 	/* Setup input device */
328 	input->name = "ILI210x Touchscreen";
329 	input->id.bustype = BUS_I2C;
330 	input->dev.parent = dev;
331 
332 	/* Multi touch */
333 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, 0xffff, 0, 0);
334 	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 0xffff, 0, 0);
335 	touchscreen_parse_properties(input, true, &priv->prop);
336 	input_mt_init_slots(input, priv->max_touches, INPUT_MT_DIRECT);
337 
338 	error = devm_add_action(dev, ili210x_cancel_work, priv);
339 	if (error)
340 		return error;
341 
342 	error = devm_request_irq(dev, client->irq, ili210x_irq, 0,
343 				 client->name, priv);
344 	if (error) {
345 		dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
346 			error);
347 		return error;
348 	}
349 
350 	error = devm_device_add_group(dev, &ili210x_attr_group);
351 	if (error) {
352 		dev_err(dev, "Unable to create sysfs attributes, err: %d\n",
353 			error);
354 		return error;
355 	}
356 
357 	error = input_register_device(priv->input);
358 	if (error) {
359 		dev_err(dev, "Cannot register input device, err: %d\n", error);
360 		return error;
361 	}
362 
363 	device_init_wakeup(dev, 1);
364 
365 	dev_dbg(dev,
366 		"ILI210x initialized (IRQ: %d), firmware version %d.%d.%d",
367 		client->irq, firmware.id, firmware.major, firmware.minor);
368 
369 	return 0;
370 }
371 
372 static int __maybe_unused ili210x_i2c_suspend(struct device *dev)
373 {
374 	struct i2c_client *client = to_i2c_client(dev);
375 
376 	if (device_may_wakeup(&client->dev))
377 		enable_irq_wake(client->irq);
378 
379 	return 0;
380 }
381 
382 static int __maybe_unused ili210x_i2c_resume(struct device *dev)
383 {
384 	struct i2c_client *client = to_i2c_client(dev);
385 
386 	if (device_may_wakeup(&client->dev))
387 		disable_irq_wake(client->irq);
388 
389 	return 0;
390 }
391 
392 static SIMPLE_DEV_PM_OPS(ili210x_i2c_pm,
393 			 ili210x_i2c_suspend, ili210x_i2c_resume);
394 
395 static const struct i2c_device_id ili210x_i2c_id[] = {
396 	{ "ili210x", MODEL_ILI210X },
397 	{ "ili251x", MODEL_ILI251X },
398 	{ }
399 };
400 MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
401 
402 static const struct of_device_id ili210x_dt_ids[] = {
403 	{ .compatible = "ilitek,ili210x", .data = (void *)MODEL_ILI210X },
404 	{ .compatible = "ilitek,ili251x", .data = (void *)MODEL_ILI251X },
405 	{ },
406 };
407 MODULE_DEVICE_TABLE(of, ili210x_dt_ids);
408 
409 static struct i2c_driver ili210x_ts_driver = {
410 	.driver = {
411 		.name = "ili210x_i2c",
412 		.pm = &ili210x_i2c_pm,
413 		.of_match_table = ili210x_dt_ids,
414 	},
415 	.id_table = ili210x_i2c_id,
416 	.probe = ili210x_i2c_probe,
417 };
418 
419 module_i2c_driver(ili210x_ts_driver);
420 
421 MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
422 MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
423 MODULE_LICENSE("GPL");
424