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egalax_ts.c
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1 /*
2  * Driver for EETI eGalax Multiple Touch Controller
3  *
4  * Copyright (C) 2011 Freescale Semiconductor, Inc.
5  *
6  * based on max11801_ts.c
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 /* EETI eGalax serial touch screen controller is a I2C based multiple
14  * touch screen controller, it supports 5 point multiple touch. */
15 
16 /* TODO:
17  - auto idle mode support
18 */
19 
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/i2c.h>
23 #include <linux/interrupt.h>
24 #include <linux/input.h>
25 #include <linux/irq.h>
26 #include <linux/gpio.h>
27 #include <linux/delay.h>
28 #include <linux/slab.h>
29 #include <linux/bitops.h>
30 #include <linux/input/mt.h>
31 #include <linux/of_gpio.h>
32 
33 /*
34  * Mouse Mode: some panel may configure the controller to mouse mode,
35  * which can only report one point at a given time.
36  * This driver will ignore events in this mode.
37  */
38 #define REPORT_MODE_MOUSE 0x1
39 /*
40  * Vendor Mode: this mode is used to transfer some vendor specific
41  * messages.
42  * This driver will ignore events in this mode.
43  */
44 #define REPORT_MODE_VENDOR 0x3
45 /* Multiple Touch Mode */
46 #define REPORT_MODE_MTTOUCH 0x4
47 
48 #define MAX_SUPPORT_POINTS 5
49 
50 #define EVENT_VALID_OFFSET 7
51 #define EVENT_VALID_MASK (0x1 << EVENT_VALID_OFFSET)
52 #define EVENT_ID_OFFSET 2
53 #define EVENT_ID_MASK (0xf << EVENT_ID_OFFSET)
54 #define EVENT_IN_RANGE (0x1 << 1)
55 #define EVENT_DOWN_UP (0X1 << 0)
56 
57 #define MAX_I2C_DATA_LEN 10
58 
59 #define EGALAX_MAX_X 32760
60 #define EGALAX_MAX_Y 32760
61 #define EGALAX_MAX_TRIES 100
62 
63 struct egalax_ts {
64  struct i2c_client *client;
66 };
67 
68 static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
69 {
70  struct egalax_ts *ts = dev_id;
71  struct input_dev *input_dev = ts->input_dev;
72  struct i2c_client *client = ts->client;
74  int id, ret, x, y, z;
75  int tries = 0;
76  bool down, valid;
77  u8 state;
78 
79  do {
80  ret = i2c_master_recv(client, buf, MAX_I2C_DATA_LEN);
81  } while (ret == -EAGAIN && tries++ < EGALAX_MAX_TRIES);
82 
83  if (ret < 0)
84  return IRQ_HANDLED;
85 
86  if (buf[0] != REPORT_MODE_MTTOUCH) {
87  /* ignore mouse events and vendor events */
88  return IRQ_HANDLED;
89  }
90 
91  state = buf[1];
92  x = (buf[3] << 8) | buf[2];
93  y = (buf[5] << 8) | buf[4];
94  z = (buf[7] << 8) | buf[6];
95 
96  valid = state & EVENT_VALID_MASK;
97  id = (state & EVENT_ID_MASK) >> EVENT_ID_OFFSET;
98  down = state & EVENT_DOWN_UP;
99 
100  if (!valid || id > MAX_SUPPORT_POINTS) {
101  dev_dbg(&client->dev, "point invalid\n");
102  return IRQ_HANDLED;
103  }
104 
105  input_mt_slot(input_dev, id);
106  input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, down);
107 
108  dev_dbg(&client->dev, "%s id:%d x:%d y:%d z:%d",
109  down ? "down" : "up", id, x, y, z);
110 
111  if (down) {
112  input_report_abs(input_dev, ABS_MT_POSITION_X, x);
113  input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
114  input_report_abs(input_dev, ABS_MT_PRESSURE, z);
115  }
116 
117  input_mt_report_pointer_emulation(input_dev, true);
118  input_sync(input_dev);
119 
120  return IRQ_HANDLED;
121 }
122 
123 /* wake up controller by an falling edge of interrupt gpio. */
124 static int egalax_wake_up_device(struct i2c_client *client)
125 {
126  struct device_node *np = client->dev.of_node;
127  int gpio;
128  int ret;
129 
130  if (!np)
131  return -ENODEV;
132 
133  gpio = of_get_named_gpio(np, "wakeup-gpios", 0);
134  if (!gpio_is_valid(gpio))
135  return -ENODEV;
136 
137  ret = gpio_request(gpio, "egalax_irq");
138  if (ret < 0) {
139  dev_err(&client->dev,
140  "request gpio failed, cannot wake up controller: %d\n",
141  ret);
142  return ret;
143  }
144 
145  /* wake up controller via an falling edge on IRQ gpio. */
146  gpio_direction_output(gpio, 0);
147  gpio_set_value(gpio, 1);
148 
149  /* controller should be waken up, return irq. */
150  gpio_direction_input(gpio);
151  gpio_free(gpio);
152 
153  return 0;
154 }
155 
156 static int __devinit egalax_firmware_version(struct i2c_client *client)
157 {
158  static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 };
159  int ret;
160 
161  ret = i2c_master_send(client, cmd, MAX_I2C_DATA_LEN);
162  if (ret < 0)
163  return ret;
164 
165  return 0;
166 }
167 
168 static int __devinit egalax_ts_probe(struct i2c_client *client,
169  const struct i2c_device_id *id)
170 {
171  struct egalax_ts *ts;
172  struct input_dev *input_dev;
173  int ret;
174  int error;
175 
176  ts = kzalloc(sizeof(struct egalax_ts), GFP_KERNEL);
177  if (!ts) {
178  dev_err(&client->dev, "Failed to allocate memory\n");
179  return -ENOMEM;
180  }
181 
182  input_dev = input_allocate_device();
183  if (!input_dev) {
184  dev_err(&client->dev, "Failed to allocate memory\n");
185  error = -ENOMEM;
186  goto err_free_ts;
187  }
188 
189  ts->client = client;
190  ts->input_dev = input_dev;
191 
192  /* controller may be in sleep, wake it up. */
193  error = egalax_wake_up_device(client);
194  if (error) {
195  dev_err(&client->dev, "Failed to wake up the controller\n");
196  goto err_free_dev;
197  }
198 
199  ret = egalax_firmware_version(client);
200  if (ret < 0) {
201  dev_err(&client->dev, "Failed to read firmware version\n");
202  error = -EIO;
203  goto err_free_dev;
204  }
205 
206  input_dev->name = "EETI eGalax Touch Screen";
207  input_dev->id.bustype = BUS_I2C;
208  input_dev->dev.parent = &client->dev;
209 
210  __set_bit(EV_ABS, input_dev->evbit);
211  __set_bit(EV_KEY, input_dev->evbit);
212  __set_bit(BTN_TOUCH, input_dev->keybit);
213 
214  input_set_abs_params(input_dev, ABS_X, 0, EGALAX_MAX_X, 0, 0);
215  input_set_abs_params(input_dev, ABS_Y, 0, EGALAX_MAX_Y, 0, 0);
216  input_set_abs_params(input_dev,
217  ABS_MT_POSITION_X, 0, EGALAX_MAX_X, 0, 0);
218  input_set_abs_params(input_dev,
219  ABS_MT_POSITION_X, 0, EGALAX_MAX_Y, 0, 0);
221 
222  input_set_drvdata(input_dev, ts);
223 
224  error = request_threaded_irq(client->irq, NULL, egalax_ts_interrupt,
226  "egalax_ts", ts);
227  if (error < 0) {
228  dev_err(&client->dev, "Failed to register interrupt\n");
229  goto err_free_dev;
230  }
231 
232  error = input_register_device(ts->input_dev);
233  if (error)
234  goto err_free_irq;
235 
236  i2c_set_clientdata(client, ts);
237  return 0;
238 
239 err_free_irq:
240  free_irq(client->irq, ts);
241 err_free_dev:
242  input_free_device(input_dev);
243 err_free_ts:
244  kfree(ts);
245 
246  return error;
247 }
248 
249 static __devexit int egalax_ts_remove(struct i2c_client *client)
250 {
251  struct egalax_ts *ts = i2c_get_clientdata(client);
252 
253  free_irq(client->irq, ts);
254 
255  input_unregister_device(ts->input_dev);
256  kfree(ts);
257 
258  return 0;
259 }
260 
261 static const struct i2c_device_id egalax_ts_id[] = {
262  { "egalax_ts", 0 },
263  { }
264 };
265 MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
266 
267 #ifdef CONFIG_PM_SLEEP
268 static int egalax_ts_suspend(struct device *dev)
269 {
270  static const u8 suspend_cmd[MAX_I2C_DATA_LEN] = {
271  0x3, 0x6, 0xa, 0x3, 0x36, 0x3f, 0x2, 0, 0, 0
272  };
273  struct i2c_client *client = to_i2c_client(dev);
274  int ret;
275 
276  ret = i2c_master_send(client, suspend_cmd, MAX_I2C_DATA_LEN);
277  return ret > 0 ? 0 : ret;
278 }
279 
280 static int egalax_ts_resume(struct device *dev)
281 {
282  struct i2c_client *client = to_i2c_client(dev);
283 
284  return egalax_wake_up_device(client);
285 }
286 #endif
287 
288 static SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops, egalax_ts_suspend, egalax_ts_resume);
289 
290 static struct of_device_id egalax_ts_dt_ids[] = {
291  { .compatible = "eeti,egalax_ts" },
292  { /* sentinel */ }
293 };
294 
295 static struct i2c_driver egalax_ts_driver = {
296  .driver = {
297  .name = "egalax_ts",
298  .owner = THIS_MODULE,
299  .pm = &egalax_ts_pm_ops,
300  .of_match_table = of_match_ptr(egalax_ts_dt_ids),
301  },
302  .id_table = egalax_ts_id,
303  .probe = egalax_ts_probe,
304  .remove = __devexit_p(egalax_ts_remove),
305 };
306 
307 module_i2c_driver(egalax_ts_driver);
308 
309 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
310 MODULE_DESCRIPTION("Touchscreen driver for EETI eGalax touch controller");
311 MODULE_LICENSE("GPL");