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/delay.h>
  8#include <linux/workqueue.h>
  9#include <linux/input/ili210x.h>
 10
 11#define MAX_TOUCHES		2
 12#define DEFAULT_POLL_PERIOD	20
 13
 14/* Touchscreen commands */
 15#define REG_TOUCHDATA		0x10
 16#define REG_PANEL_INFO		0x20
 17#define REG_FIRMWARE_VERSION	0x40
 18#define REG_CALIBRATE		0xcc
 19
 20struct finger {
 21	u8 x_low;
 22	u8 x_high;
 23	u8 y_low;
 24	u8 y_high;
 25} __packed;
 26
 27struct touchdata {
 28	u8 status;
 29	struct finger finger[MAX_TOUCHES];
 30} __packed;
 31
 32struct panel_info {
 33	struct finger finger_max;
 34	u8 xchannel_num;
 35	u8 ychannel_num;
 36} __packed;
 37
 38struct firmware_version {
 39	u8 id;
 40	u8 major;
 41	u8 minor;
 42} __packed;
 43
 44struct ili210x {
 45	struct i2c_client *client;
 46	struct input_dev *input;
 47	bool (*get_pendown_state)(void);
 48	unsigned int poll_period;
 49	struct delayed_work dwork;
 50};
 51
 52static int ili210x_read_reg(struct i2c_client *client, u8 reg, void *buf,
 53			    size_t len)
 54{
 55	struct i2c_msg msg[2] = {
 56		{
 57			.addr	= client->addr,
 58			.flags	= 0,
 59			.len	= 1,
 60			.buf	= &reg,
 61		},
 62		{
 63			.addr	= client->addr,
 64			.flags	= I2C_M_RD,
 65			.len	= len,
 66			.buf	= buf,
 67		}
 68	};
 69
 70	if (i2c_transfer(client->adapter, msg, 2) != 2) {
 71		dev_err(&client->dev, "i2c transfer failed\n");
 72		return -EIO;
 73	}
 74
 75	return 0;
 76}
 77
 78static void ili210x_report_events(struct input_dev *input,
 79				  const struct touchdata *touchdata)
 80{
 81	int i;
 82	bool touch;
 83	unsigned int x, y;
 84	const struct finger *finger;
 85
 86	for (i = 0; i < MAX_TOUCHES; i++) {
 87		input_mt_slot(input, i);
 88
 89		finger = &touchdata->finger[i];
 90
 91		touch = touchdata->status & (1 << i);
 92		input_mt_report_slot_state(input, MT_TOOL_FINGER, touch);
 93		if (touch) {
 94			x = finger->x_low | (finger->x_high << 8);
 95			y = finger->y_low | (finger->y_high << 8);
 96
 97			input_report_abs(input, ABS_MT_POSITION_X, x);
 98			input_report_abs(input, ABS_MT_POSITION_Y, y);
 99		}
100	}
101
102	input_mt_report_pointer_emulation(input, false);
103	input_sync(input);
104}
105
106static bool get_pendown_state(const struct ili210x *priv)
107{
108	bool state = false;
109
110	if (priv->get_pendown_state)
111		state = priv->get_pendown_state();
112
113	return state;
114}
115
116static void ili210x_work(struct work_struct *work)
117{
118	struct ili210x *priv = container_of(work, struct ili210x,
119					    dwork.work);
120	struct i2c_client *client = priv->client;
121	struct touchdata touchdata;
122	int error;
123
124	error = ili210x_read_reg(client, REG_TOUCHDATA,
125				 &touchdata, sizeof(touchdata));
126	if (error) {
127		dev_err(&client->dev,
128			"Unable to get touchdata, err = %d\n", error);
129		return;
130	}
131
132	ili210x_report_events(priv->input, &touchdata);
133
134	if ((touchdata.status & 0xf3) || get_pendown_state(priv))
135		schedule_delayed_work(&priv->dwork,
136				      msecs_to_jiffies(priv->poll_period));
137}
138
139static irqreturn_t ili210x_irq(int irq, void *irq_data)
140{
141	struct ili210x *priv = irq_data;
142
143	schedule_delayed_work(&priv->dwork, 0);
144
145	return IRQ_HANDLED;
146}
147
148static ssize_t ili210x_calibrate(struct device *dev,
149				 struct device_attribute *attr,
150				 const char *buf, size_t count)
151{
152	struct i2c_client *client = to_i2c_client(dev);
153	struct ili210x *priv = i2c_get_clientdata(client);
154	unsigned long calibrate;
155	int rc;
156	u8 cmd = REG_CALIBRATE;
157
158	if (kstrtoul(buf, 10, &calibrate))
159		return -EINVAL;
160
161	if (calibrate > 1)
162		return -EINVAL;
163
164	if (calibrate) {
165		rc = i2c_master_send(priv->client, &cmd, sizeof(cmd));
166		if (rc != sizeof(cmd))
167			return -EIO;
168	}
169
170	return count;
171}
172static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
173
174static struct attribute *ili210x_attributes[] = {
175	&dev_attr_calibrate.attr,
176	NULL,
177};
178
179static const struct attribute_group ili210x_attr_group = {
180	.attrs = ili210x_attributes,
181};
182
183static int ili210x_i2c_probe(struct i2c_client *client,
184				       const struct i2c_device_id *id)
185{
186	struct device *dev = &client->dev;
187	const struct ili210x_platform_data *pdata = dev_get_platdata(dev);
188	struct ili210x *priv;
189	struct input_dev *input;
190	struct panel_info panel;
191	struct firmware_version firmware;
192	int xmax, ymax;
193	int error;
194
195	dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
196
197	if (!pdata) {
198		dev_err(dev, "No platform data!\n");
199		return -EINVAL;
200	}
201
202	if (client->irq <= 0) {
203		dev_err(dev, "No IRQ!\n");
204		return -EINVAL;
205	}
206
207	/* Get firmware version */
208	error = ili210x_read_reg(client, REG_FIRMWARE_VERSION,
209				 &firmware, sizeof(firmware));
210	if (error) {
211		dev_err(dev, "Failed to get firmware version, err: %d\n",
212			error);
213		return error;
214	}
215
216	/* get panel info */
217	error = ili210x_read_reg(client, REG_PANEL_INFO, &panel, sizeof(panel));
218	if (error) {
219		dev_err(dev, "Failed to get panel information, err: %d\n",
220			error);
221		return error;
222	}
223
224	xmax = panel.finger_max.x_low | (panel.finger_max.x_high << 8);
225	ymax = panel.finger_max.y_low | (panel.finger_max.y_high << 8);
226
227	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
228	input = input_allocate_device();
229	if (!priv || !input) {
230		error = -ENOMEM;
231		goto err_free_mem;
232	}
233
234	priv->client = client;
235	priv->input = input;
236	priv->get_pendown_state = pdata->get_pendown_state;
237	priv->poll_period = pdata->poll_period ? : DEFAULT_POLL_PERIOD;
238	INIT_DELAYED_WORK(&priv->dwork, ili210x_work);
239
240	/* Setup input device */
241	input->name = "ILI210x Touchscreen";
242	input->id.bustype = BUS_I2C;
243	input->dev.parent = dev;
244
245	__set_bit(EV_SYN, input->evbit);
246	__set_bit(EV_KEY, input->evbit);
247	__set_bit(EV_ABS, input->evbit);
248	__set_bit(BTN_TOUCH, input->keybit);
249
250	/* Single touch */
251	input_set_abs_params(input, ABS_X, 0, xmax, 0, 0);
252	input_set_abs_params(input, ABS_Y, 0, ymax, 0, 0);
253
254	/* Multi touch */
255	input_mt_init_slots(input, MAX_TOUCHES, 0);
256	input_set_abs_params(input, ABS_MT_POSITION_X, 0, xmax, 0, 0);
257	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ymax, 0, 0);
258
259	i2c_set_clientdata(client, priv);
260
261	error = request_irq(client->irq, ili210x_irq, pdata->irq_flags,
262			    client->name, priv);
263	if (error) {
264		dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
265			error);
266		goto err_free_mem;
267	}
268
269	error = sysfs_create_group(&dev->kobj, &ili210x_attr_group);
270	if (error) {
271		dev_err(dev, "Unable to create sysfs attributes, err: %d\n",
272			error);
273		goto err_free_irq;
274	}
275
276	error = input_register_device(priv->input);
277	if (error) {
278		dev_err(dev, "Cannot register input device, err: %d\n", error);
279		goto err_remove_sysfs;
280	}
281
282	device_init_wakeup(dev, 1);
283
284	dev_dbg(dev,
285		"ILI210x initialized (IRQ: %d), firmware version %d.%d.%d",
286		client->irq, firmware.id, firmware.major, firmware.minor);
287
288	return 0;
289
290err_remove_sysfs:
291	sysfs_remove_group(&dev->kobj, &ili210x_attr_group);
292err_free_irq:
293	free_irq(client->irq, priv);
294err_free_mem:
295	input_free_device(input);
296	kfree(priv);
297	return error;
298}
299
300static int ili210x_i2c_remove(struct i2c_client *client)
301{
302	struct ili210x *priv = i2c_get_clientdata(client);
303
304	sysfs_remove_group(&client->dev.kobj, &ili210x_attr_group);
305	free_irq(priv->client->irq, priv);
306	cancel_delayed_work_sync(&priv->dwork);
307	input_unregister_device(priv->input);
308	kfree(priv);
309
310	return 0;
311}
312
313static int __maybe_unused ili210x_i2c_suspend(struct device *dev)
314{
315	struct i2c_client *client = to_i2c_client(dev);
316
317	if (device_may_wakeup(&client->dev))
318		enable_irq_wake(client->irq);
319
320	return 0;
321}
322
323static int __maybe_unused ili210x_i2c_resume(struct device *dev)
324{
325	struct i2c_client *client = to_i2c_client(dev);
326
327	if (device_may_wakeup(&client->dev))
328		disable_irq_wake(client->irq);
329
330	return 0;
331}
332
333static SIMPLE_DEV_PM_OPS(ili210x_i2c_pm,
334			 ili210x_i2c_suspend, ili210x_i2c_resume);
335
336static const struct i2c_device_id ili210x_i2c_id[] = {
337	{ "ili210x", 0 },
338	{ }
339};
340MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
341
342static struct i2c_driver ili210x_ts_driver = {
343	.driver = {
344		.name = "ili210x_i2c",
345		.pm = &ili210x_i2c_pm,
346	},
347	.id_table = ili210x_i2c_id,
348	.probe = ili210x_i2c_probe,
349	.remove = ili210x_i2c_remove,
350};
351
352module_i2c_driver(ili210x_ts_driver);
353
354MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
355MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
356MODULE_LICENSE("GPL");