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Linux/drivers/input/touchscreen/egalax_ts.c

  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/i2c.h>
 22 #include <linux/interrupt.h>
 23 #include <linux/input.h>
 24 #include <linux/irq.h>
 25 #include <linux/gpio.h>
 26 #include <linux/delay.h>
 27 #include <linux/slab.h>
 28 #include <linux/bitops.h>
 29 #include <linux/input/mt.h>
 30 #include <linux/of_gpio.h>
 31 
 32 /*
 33  * Mouse Mode: some panel may configure the controller to mouse mode,
 34  * which can only report one point at a given time.
 35  * This driver will ignore events in this mode.
 36  */
 37 #define REPORT_MODE_MOUSE               0x1
 38 /*
 39  * Vendor Mode: this mode is used to transfer some vendor specific
 40  * messages.
 41  * This driver will ignore events in this mode.
 42  */
 43 #define REPORT_MODE_VENDOR              0x3
 44 /* Multiple Touch Mode */
 45 #define REPORT_MODE_MTTOUCH             0x4
 46 
 47 #define MAX_SUPPORT_POINTS              5
 48 
 49 #define EVENT_VALID_OFFSET      7
 50 #define EVENT_VALID_MASK        (0x1 << EVENT_VALID_OFFSET)
 51 #define EVENT_ID_OFFSET         2
 52 #define EVENT_ID_MASK           (0xf << EVENT_ID_OFFSET)
 53 #define EVENT_IN_RANGE          (0x1 << 1)
 54 #define EVENT_DOWN_UP           (0X1 << 0)
 55 
 56 #define MAX_I2C_DATA_LEN        10
 57 
 58 #define EGALAX_MAX_X    32760
 59 #define EGALAX_MAX_Y    32760
 60 #define EGALAX_MAX_TRIES 100
 61 
 62 struct egalax_ts {
 63         struct i2c_client               *client;
 64         struct input_dev                *input_dev;
 65 };
 66 
 67 static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
 68 {
 69         struct egalax_ts *ts = dev_id;
 70         struct input_dev *input_dev = ts->input_dev;
 71         struct i2c_client *client = ts->client;
 72         u8 buf[MAX_I2C_DATA_LEN];
 73         int id, ret, x, y, z;
 74         int tries = 0;
 75         bool down, valid;
 76         u8 state;
 77 
 78         do {
 79                 ret = i2c_master_recv(client, buf, MAX_I2C_DATA_LEN);
 80         } while (ret == -EAGAIN && tries++ < EGALAX_MAX_TRIES);
 81 
 82         if (ret < 0)
 83                 return IRQ_HANDLED;
 84 
 85         if (buf[0] != REPORT_MODE_MTTOUCH) {
 86                 /* ignore mouse events and vendor events */
 87                 return IRQ_HANDLED;
 88         }
 89 
 90         state = buf[1];
 91         x = (buf[3] << 8) | buf[2];
 92         y = (buf[5] << 8) | buf[4];
 93         z = (buf[7] << 8) | buf[6];
 94 
 95         valid = state & EVENT_VALID_MASK;
 96         id = (state & EVENT_ID_MASK) >> EVENT_ID_OFFSET;
 97         down = state & EVENT_DOWN_UP;
 98 
 99         if (!valid || id > MAX_SUPPORT_POINTS) {
100                 dev_dbg(&client->dev, "point invalid\n");
101                 return IRQ_HANDLED;
102         }
103 
104         input_mt_slot(input_dev, id);
105         input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, down);
106 
107         dev_dbg(&client->dev, "%s id:%d x:%d y:%d z:%d",
108                 down ? "down" : "up", id, x, y, z);
109 
110         if (down) {
111                 input_report_abs(input_dev, ABS_MT_POSITION_X, x);
112                 input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
113                 input_report_abs(input_dev, ABS_MT_PRESSURE, z);
114         }
115 
116         input_mt_report_pointer_emulation(input_dev, true);
117         input_sync(input_dev);
118 
119         return IRQ_HANDLED;
120 }
121 
122 /* wake up controller by an falling edge of interrupt gpio.  */
123 static int egalax_wake_up_device(struct i2c_client *client)
124 {
125         struct device_node *np = client->dev.of_node;
126         int gpio;
127         int ret;
128 
129         if (!np)
130                 return -ENODEV;
131 
132         gpio = of_get_named_gpio(np, "wakeup-gpios", 0);
133         if (!gpio_is_valid(gpio))
134                 return -ENODEV;
135 
136         ret = gpio_request(gpio, "egalax_irq");
137         if (ret < 0) {
138                 dev_err(&client->dev,
139                         "request gpio failed, cannot wake up controller: %d\n",
140                         ret);
141                 return ret;
142         }
143 
144         /* wake up controller via an falling edge on IRQ gpio. */
145         gpio_direction_output(gpio, 0);
146         gpio_set_value(gpio, 1);
147 
148         /* controller should be waken up, return irq.  */
149         gpio_direction_input(gpio);
150         gpio_free(gpio);
151 
152         return 0;
153 }
154 
155 static int egalax_firmware_version(struct i2c_client *client)
156 {
157         static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 };
158         int ret;
159 
160         ret = i2c_master_send(client, cmd, MAX_I2C_DATA_LEN);
161         if (ret < 0)
162                 return ret;
163 
164         return 0;
165 }
166 
167 static int egalax_ts_probe(struct i2c_client *client,
168                            const struct i2c_device_id *id)
169 {
170         struct egalax_ts *ts;
171         struct input_dev *input_dev;
172         int error;
173 
174         ts = devm_kzalloc(&client->dev, sizeof(struct egalax_ts), GFP_KERNEL);
175         if (!ts) {
176                 dev_err(&client->dev, "Failed to allocate memory\n");
177                 return -ENOMEM;
178         }
179 
180         input_dev = devm_input_allocate_device(&client->dev);
181         if (!input_dev) {
182                 dev_err(&client->dev, "Failed to allocate memory\n");
183                 return -ENOMEM;
184         }
185 
186         ts->client = client;
187         ts->input_dev = input_dev;
188 
189         /* controller may be in sleep, wake it up. */
190         error = egalax_wake_up_device(client);
191         if (error) {
192                 dev_err(&client->dev, "Failed to wake up the controller\n");
193                 return error;
194         }
195 
196         error = egalax_firmware_version(client);
197         if (error < 0) {
198                 dev_err(&client->dev, "Failed to read firmware version\n");
199                 return error;
200         }
201 
202         input_dev->name = "EETI eGalax Touch Screen";
203         input_dev->id.bustype = BUS_I2C;
204 
205         __set_bit(EV_ABS, input_dev->evbit);
206         __set_bit(EV_KEY, input_dev->evbit);
207         __set_bit(BTN_TOUCH, input_dev->keybit);
208 
209         input_set_abs_params(input_dev, ABS_X, 0, EGALAX_MAX_X, 0, 0);
210         input_set_abs_params(input_dev, ABS_Y, 0, EGALAX_MAX_Y, 0, 0);
211         input_set_abs_params(input_dev,
212                              ABS_MT_POSITION_X, 0, EGALAX_MAX_X, 0, 0);
213         input_set_abs_params(input_dev,
214                              ABS_MT_POSITION_Y, 0, EGALAX_MAX_Y, 0, 0);
215         input_mt_init_slots(input_dev, MAX_SUPPORT_POINTS, 0);
216 
217         input_set_drvdata(input_dev, ts);
218 
219         error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
220                                           egalax_ts_interrupt,
221                                           IRQF_TRIGGER_LOW | IRQF_ONESHOT,
222                                           "egalax_ts", ts);
223         if (error < 0) {
224                 dev_err(&client->dev, "Failed to register interrupt\n");
225                 return error;
226         }
227 
228         error = input_register_device(ts->input_dev);
229         if (error)
230                 return error;
231 
232         i2c_set_clientdata(client, ts);
233         return 0;
234 }
235 
236 static const struct i2c_device_id egalax_ts_id[] = {
237         { "egalax_ts", 0 },
238         { }
239 };
240 MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
241 
242 #ifdef CONFIG_PM_SLEEP
243 static int egalax_ts_suspend(struct device *dev)
244 {
245         static const u8 suspend_cmd[MAX_I2C_DATA_LEN] = {
246                 0x3, 0x6, 0xa, 0x3, 0x36, 0x3f, 0x2, 0, 0, 0
247         };
248         struct i2c_client *client = to_i2c_client(dev);
249         int ret;
250 
251         ret = i2c_master_send(client, suspend_cmd, MAX_I2C_DATA_LEN);
252         return ret > 0 ? 0 : ret;
253 }
254 
255 static int egalax_ts_resume(struct device *dev)
256 {
257         struct i2c_client *client = to_i2c_client(dev);
258 
259         return egalax_wake_up_device(client);
260 }
261 #endif
262 
263 static SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops, egalax_ts_suspend, egalax_ts_resume);
264 
265 static const struct of_device_id egalax_ts_dt_ids[] = {
266         { .compatible = "eeti,egalax_ts" },
267         { /* sentinel */ }
268 };
269 
270 static struct i2c_driver egalax_ts_driver = {
271         .driver = {
272                 .name   = "egalax_ts",
273                 .owner  = THIS_MODULE,
274                 .pm     = &egalax_ts_pm_ops,
275                 .of_match_table = egalax_ts_dt_ids,
276         },
277         .id_table       = egalax_ts_id,
278         .probe          = egalax_ts_probe,
279 };
280 
281 module_i2c_driver(egalax_ts_driver);
282 
283 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
284 MODULE_DESCRIPTION("Touchscreen driver for EETI eGalax touch controller");
285 MODULE_LICENSE("GPL");
286 

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