1// SPDX-License-Identifier: GPL-2.0-only
  2#include <linux/module.h>
  3#include <linux/i2c.h>
  4#include <linux/interrupt.h>
  5#include <linux/slab.h>
  6#include <linux/input.h>
  7#include <linux/input/mt.h>
  8#include <linux/input/touchscreen.h>
  9#include <linux/delay.h>
 10#include <linux/workqueue.h>
 11#include <linux/gpio/consumer.h>
 12#include <linux/of_device.h>
 13#include <asm/unaligned.h>
 14
 15#define ILI210X_TOUCHES		2
 16#define ILI251X_TOUCHES		10
 17#define DEFAULT_POLL_PERIOD	20
 18
 19/* Touchscreen commands */
 20#define REG_TOUCHDATA		0x10
 21#define REG_PANEL_INFO		0x20
 22#define REG_FIRMWARE_VERSION	0x40
 23#define REG_CALIBRATE		0xcc
 24
 25struct firmware_version {
 26	u8 id;
 27	u8 major;
 28	u8 minor;
 29} __packed;
 30
 31enum ili2xxx_model {
 32	MODEL_ILI210X,
 33	MODEL_ILI251X,
 34};
 35
 36struct ili210x {
 37	struct i2c_client *client;
 38	struct input_dev *input;
 39	unsigned int poll_period;
 40	struct delayed_work dwork;
 41	struct gpio_desc *reset_gpio;
 42	struct touchscreen_properties prop;
 43	enum ili2xxx_model model;
 44	unsigned int max_touches;
 45};
 46
 47static int ili210x_read_reg(struct i2c_client *client, u8 reg, void *buf,
 48			    size_t len)
 49{
 50	struct ili210x *priv = i2c_get_clientdata(client);
 51	struct i2c_msg msg[2] = {
 52		{
 53			.addr	= client->addr,
 54			.flags	= 0,
 55			.len	= 1,
 56			.buf	= &reg,
 57		},
 58		{
 59			.addr	= client->addr,
 60			.flags	= I2C_M_RD,
 61			.len	= len,
 62			.buf	= buf,
 63		}
 64	};
 65
 66	if (priv->model == MODEL_ILI251X) {
 67		if (i2c_transfer(client->adapter, msg, 1) != 1) {
 68			dev_err(&client->dev, "i2c transfer failed\n");
 69			return -EIO;
 70		}
 71
 72		usleep_range(5000, 5500);
 73
 74		if (i2c_transfer(client->adapter, msg + 1, 1) != 1) {
 75			dev_err(&client->dev, "i2c transfer failed\n");
 76			return -EIO;
 77		}
 78	} else {
 79		if (i2c_transfer(client->adapter, msg, 2) != 2) {
 80			dev_err(&client->dev, "i2c transfer failed\n");
 81			return -EIO;
 82		}
 83	}
 84
 85	return 0;
 86}
 87
 88static int ili210x_read(struct i2c_client *client, void *buf, size_t len)
 89{
 90	struct i2c_msg msg = {
 91		.addr	= client->addr,
 92		.flags	= I2C_M_RD,
 93		.len	= len,
 94		.buf	= buf,
 95	};
 96
 97	if (i2c_transfer(client->adapter, &msg, 1) != 1) {
 98		dev_err(&client->dev, "i2c transfer failed\n");
 99		return -EIO;
100	}
101
102	return 0;
103}
104
105static bool ili210x_touchdata_to_coords(struct ili210x *priv, u8 *touchdata,
106					unsigned int finger,
107					unsigned int *x, unsigned int *y)
108{
109	if (finger >= ILI210X_TOUCHES)
110		return false;
111
112	if (touchdata[0] & BIT(finger))
113		return false;
114
115	*x = get_unaligned_be16(touchdata + 1 + (finger * 4) + 0);
116	*y = get_unaligned_be16(touchdata + 1 + (finger * 4) + 2);
117
118	return true;
119}
120
121static bool ili251x_touchdata_to_coords(struct ili210x *priv, u8 *touchdata,
122					unsigned int finger,
123					unsigned int *x, unsigned int *y)
124{
125	if (finger >= ILI251X_TOUCHES)
126		return false;
127
128	*x = get_unaligned_be16(touchdata + 1 + (finger * 5) + 0);
129	if (!(*x & BIT(15)))	/* Touch indication */
130		return false;
131
132	*x &= 0x3fff;
133	*y = get_unaligned_be16(touchdata + 1 + (finger * 5) + 2);
134
135	return true;
136}
137
138static bool ili210x_report_events(struct ili210x *priv, u8 *touchdata)
139{
140	struct input_dev *input = priv->input;
141	int i;
142	bool contact = false, touch = false;
143	unsigned int x = 0, y = 0;
144
145	for (i = 0; i < priv->max_touches; i++) {
146		if (priv->model == MODEL_ILI210X) {
147			touch = ili210x_touchdata_to_coords(priv, touchdata,
148							    i, &x, &y);
149		} else if (priv->model == MODEL_ILI251X) {
150			touch = ili251x_touchdata_to_coords(priv, touchdata,
151							    i, &x, &y);
152			if (touch)
153				contact = true;
154		}
155
156		input_mt_slot(input, i);
157		input_mt_report_slot_state(input, MT_TOOL_FINGER, touch);
158		if (!touch)
159			continue;
160		touchscreen_report_pos(input, &priv->prop, x, y,
161				       true);
162	}
163
164	input_mt_report_pointer_emulation(input, false);
165	input_sync(input);
166
167	if (priv->model == MODEL_ILI210X)
168		contact = touchdata[0] & 0xf3;
169
170	return contact;
171}
172
173static void ili210x_work(struct work_struct *work)
174{
175	struct ili210x *priv = container_of(work, struct ili210x,
176					    dwork.work);
177	struct i2c_client *client = priv->client;
178	u8 touchdata[64] = { 0 };
179	bool touch;
180	int error = -EINVAL;
181
182	if (priv->model == MODEL_ILI210X) {
183		error = ili210x_read_reg(client, REG_TOUCHDATA,
184					 touchdata, sizeof(touchdata));
185	} else if (priv->model == MODEL_ILI251X) {
186		error = ili210x_read_reg(client, REG_TOUCHDATA,
187					 touchdata, 31);
188		if (!error && touchdata[0] == 2)
189			error = ili210x_read(client, &touchdata[31], 20);
190	}
191
192	if (error) {
193		dev_err(&client->dev,
194			"Unable to get touchdata, err = %d\n", error);
195		return;
196	}
197
198	touch = ili210x_report_events(priv, touchdata);
199
200	if (touch)
201		schedule_delayed_work(&priv->dwork,
202				      msecs_to_jiffies(priv->poll_period));
203}
204
205static irqreturn_t ili210x_irq(int irq, void *irq_data)
206{
207	struct ili210x *priv = irq_data;
208
209	schedule_delayed_work(&priv->dwork, 0);
210
211	return IRQ_HANDLED;
212}
213
214static ssize_t ili210x_calibrate(struct device *dev,
215				 struct device_attribute *attr,
216				 const char *buf, size_t count)
217{
218	struct i2c_client *client = to_i2c_client(dev);
219	struct ili210x *priv = i2c_get_clientdata(client);
220	unsigned long calibrate;
221	int rc;
222	u8 cmd = REG_CALIBRATE;
223
224	if (kstrtoul(buf, 10, &calibrate))
225		return -EINVAL;
226
227	if (calibrate > 1)
228		return -EINVAL;
229
230	if (calibrate) {
231		rc = i2c_master_send(priv->client, &cmd, sizeof(cmd));
232		if (rc != sizeof(cmd))
233			return -EIO;
234	}
235
236	return count;
237}
238static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
239
240static struct attribute *ili210x_attributes[] = {
241	&dev_attr_calibrate.attr,
242	NULL,
243};
244
245static const struct attribute_group ili210x_attr_group = {
246	.attrs = ili210x_attributes,
247};
248
249static void ili210x_power_down(void *data)
250{
251	struct gpio_desc *reset_gpio = data;
252
253	gpiod_set_value_cansleep(reset_gpio, 1);
254}
255
256static void ili210x_cancel_work(void *data)
257{
258	struct ili210x *priv = data;
259
260	cancel_delayed_work_sync(&priv->dwork);
261}
262
263static int ili210x_i2c_probe(struct i2c_client *client,
264				       const struct i2c_device_id *id)
265{
266	struct device *dev = &client->dev;
267	struct ili210x *priv;
268	struct gpio_desc *reset_gpio;
269	struct input_dev *input;
270	struct firmware_version firmware;
271	enum ili2xxx_model model;
272	int error;
273
274	model = (enum ili2xxx_model)id->driver_data;
275
276	dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
277
278	if (client->irq <= 0) {
279		dev_err(dev, "No IRQ!\n");
280		return -EINVAL;
281	}
282
283	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
284	if (IS_ERR(reset_gpio))
285		return PTR_ERR(reset_gpio);
286
287	if (reset_gpio) {
288		error = devm_add_action_or_reset(dev, ili210x_power_down,
289						 reset_gpio);
290		if (error)
291			return error;
292
293		usleep_range(50, 100);
294		gpiod_set_value_cansleep(reset_gpio, 0);
295		msleep(100);
296	}
297
298	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
299	if (!priv)
300		return -ENOMEM;
301
302	input = devm_input_allocate_device(dev);
303	if (!input)
304		return -ENOMEM;
305
306	priv->client = client;
307	priv->input = input;
308	priv->poll_period = DEFAULT_POLL_PERIOD;
309	INIT_DELAYED_WORK(&priv->dwork, ili210x_work);
310	priv->reset_gpio = reset_gpio;
311	priv->model = model;
312	if (model == MODEL_ILI210X)
313		priv->max_touches = ILI210X_TOUCHES;
314	if (model == MODEL_ILI251X)
315		priv->max_touches = ILI251X_TOUCHES;
316
317	i2c_set_clientdata(client, priv);
318
319	/* Get firmware version */
320	error = ili210x_read_reg(client, REG_FIRMWARE_VERSION,
321				 &firmware, sizeof(firmware));
322	if (error) {
323		dev_err(dev, "Failed to get firmware version, err: %d\n",
324			error);
325		return error;
326	}
327
328	/* Setup input device */
329	input->name = "ILI210x Touchscreen";
330	input->id.bustype = BUS_I2C;
331	input->dev.parent = dev;
332
333	/* Multi touch */
334	input_set_abs_params(input, ABS_MT_POSITION_X, 0, 0xffff, 0, 0);
335	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 0xffff, 0, 0);
336	touchscreen_parse_properties(input, true, &priv->prop);
337	input_mt_init_slots(input, priv->max_touches, INPUT_MT_DIRECT);
338
339	error = devm_add_action(dev, ili210x_cancel_work, priv);
340	if (error)
341		return error;
342
343	error = devm_request_irq(dev, client->irq, ili210x_irq, 0,
344				 client->name, priv);
345	if (error) {
346		dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
347			error);
348		return error;
349	}
350
351	error = devm_device_add_group(dev, &ili210x_attr_group);
352	if (error) {
353		dev_err(dev, "Unable to create sysfs attributes, err: %d\n",
354			error);
355		return error;
356	}
357
358	error = input_register_device(priv->input);
359	if (error) {
360		dev_err(dev, "Cannot register input device, err: %d\n", error);
361		return error;
362	}
363
364	device_init_wakeup(dev, 1);
365
366	dev_dbg(dev,
367		"ILI210x initialized (IRQ: %d), firmware version %d.%d.%d",
368		client->irq, firmware.id, firmware.major, firmware.minor);
369
370	return 0;
371}
372
373static int __maybe_unused ili210x_i2c_suspend(struct device *dev)
374{
375	struct i2c_client *client = to_i2c_client(dev);
376
377	if (device_may_wakeup(&client->dev))
378		enable_irq_wake(client->irq);
379
380	return 0;
381}
382
383static int __maybe_unused ili210x_i2c_resume(struct device *dev)
384{
385	struct i2c_client *client = to_i2c_client(dev);
386
387	if (device_may_wakeup(&client->dev))
388		disable_irq_wake(client->irq);
389
390	return 0;
391}
392
393static SIMPLE_DEV_PM_OPS(ili210x_i2c_pm,
394			 ili210x_i2c_suspend, ili210x_i2c_resume);
395
396static const struct i2c_device_id ili210x_i2c_id[] = {
397	{ "ili210x", MODEL_ILI210X },
398	{ "ili251x", MODEL_ILI251X },
399	{ }
400};
401MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
402
403static const struct of_device_id ili210x_dt_ids[] = {
404	{ .compatible = "ilitek,ili210x", .data = (void *)MODEL_ILI210X },
405	{ .compatible = "ilitek,ili251x", .data = (void *)MODEL_ILI251X },
406	{ },
407};
408MODULE_DEVICE_TABLE(of, ili210x_dt_ids);
409
410static struct i2c_driver ili210x_ts_driver = {
411	.driver = {
412		.name = "ili210x_i2c",
413		.pm = &ili210x_i2c_pm,
414		.of_match_table = ili210x_dt_ids,
415	},
416	.id_table = ili210x_i2c_id,
417	.probe = ili210x_i2c_probe,
418};
419
420module_i2c_driver(ili210x_ts_driver);
421
422MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
423MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
424MODULE_LICENSE("GPL");