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, 0644, 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 informations, 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	input_set_drvdata(input, priv);
260	i2c_set_clientdata(client, priv);
261
262	error = request_irq(client->irq, ili210x_irq, pdata->irq_flags,
263			    client->name, priv);
264	if (error) {
265		dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
266			error);
267		goto err_free_mem;
268	}
269
270	error = sysfs_create_group(&dev->kobj, &ili210x_attr_group);
271	if (error) {
272		dev_err(dev, "Unable to create sysfs attributes, err: %d\n",
273			error);
274		goto err_free_irq;
275	}
276
277	error = input_register_device(priv->input);
278	if (error) {
279		dev_err(dev, "Cannot regiser input device, err: %d\n", error);
280		goto err_remove_sysfs;
281	}
282
283	device_init_wakeup(&client->dev, 1);
284
285	dev_dbg(dev,
286		"ILI210x initialized (IRQ: %d), firmware version %d.%d.%d",
287		client->irq, firmware.id, firmware.major, firmware.minor);
288
289	return 0;
290
291err_remove_sysfs:
292	sysfs_remove_group(&dev->kobj, &ili210x_attr_group);
293err_free_irq:
294	free_irq(client->irq, priv);
295err_free_mem:
296	input_free_device(input);
297	kfree(priv);
298	return error;
299}
300
301static int ili210x_i2c_remove(struct i2c_client *client)
302{
303	struct ili210x *priv = i2c_get_clientdata(client);
304
305	sysfs_remove_group(&client->dev.kobj, &ili210x_attr_group);
306	free_irq(priv->client->irq, priv);
307	cancel_delayed_work_sync(&priv->dwork);
308	input_unregister_device(priv->input);
309	kfree(priv);
310
311	return 0;
312}
313
314static int __maybe_unused ili210x_i2c_suspend(struct device *dev)
315{
316	struct i2c_client *client = to_i2c_client(dev);
317
318	if (device_may_wakeup(&client->dev))
319		enable_irq_wake(client->irq);
320
321	return 0;
322}
323
324static int __maybe_unused ili210x_i2c_resume(struct device *dev)
325{
326	struct i2c_client *client = to_i2c_client(dev);
327
328	if (device_may_wakeup(&client->dev))
329		disable_irq_wake(client->irq);
330
331	return 0;
332}
333
334static SIMPLE_DEV_PM_OPS(ili210x_i2c_pm,
335			 ili210x_i2c_suspend, ili210x_i2c_resume);
336
337static const struct i2c_device_id ili210x_i2c_id[] = {
338	{ "ili210x", 0 },
339	{ }
340};
341MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
342
343static struct i2c_driver ili210x_ts_driver = {
344	.driver = {
345		.name = "ili210x_i2c",
346		.owner = THIS_MODULE,
347		.pm = &ili210x_i2c_pm,
348	},
349	.id_table = ili210x_i2c_id,
350	.probe = ili210x_i2c_probe,
351	.remove = ili210x_i2c_remove,
352};
353
354module_i2c_driver(ili210x_ts_driver);
355
356MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
357MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
358MODULE_LICENSE("GPL");
359