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 
20 struct finger {
21 	u8 x_low;
22 	u8 x_high;
23 	u8 y_low;
24 	u8 y_high;
25 } __packed;
26 
27 struct touchdata {
28 	u8 status;
29 	struct finger finger[MAX_TOUCHES];
30 } __packed;
31 
32 struct panel_info {
33 	struct finger finger_max;
34 	u8 xchannel_num;
35 	u8 ychannel_num;
36 } __packed;
37 
38 struct firmware_version {
39 	u8 id;
40 	u8 major;
41 	u8 minor;
42 } __packed;
43 
44 struct 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 
52 static 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 
78 static 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 
106 static 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 
116 static 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 
139 static 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 
148 static 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 }
172 static DEVICE_ATTR(calibrate, 0644, NULL, ili210x_calibrate);
173 
174 static struct attribute *ili210x_attributes[] = {
175 	&dev_attr_calibrate.attr,
176 	NULL,
177 };
178 
179 static const struct attribute_group ili210x_attr_group = {
180 	.attrs = ili210x_attributes,
181 };
182 
183 static 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 
291 err_remove_sysfs:
292 	sysfs_remove_group(&dev->kobj, &ili210x_attr_group);
293 err_free_irq:
294 	free_irq(client->irq, priv);
295 err_free_mem:
296 	input_free_device(input);
297 	kfree(priv);
298 	return error;
299 }
300 
301 static 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 
314 static 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 
324 static 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 
334 static SIMPLE_DEV_PM_OPS(ili210x_i2c_pm,
335 			 ili210x_i2c_suspend, ili210x_i2c_resume);
336 
337 static const struct i2c_device_id ili210x_i2c_id[] = {
338 	{ "ili210x", 0 },
339 	{ }
340 };
341 MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
342 
343 static 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 
354 module_i2c_driver(ili210x_ts_driver);
355 
356 MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
357 MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
358 MODULE_LICENSE("GPL");
359