drivers/input/touchscreen/st1232.c

   1 /*
   2  * ST1232 Touchscreen Controller Driver
   3  *
   4  * Copyright (C) 2010 Renesas Solutions Corp.
   5  *      Tony SIM <chinyeow.sim.xt@renesas.com>
   6  *
   7  * Using code from:
   8  *  - android.git.kernel.org: projects/kernel/common.git: synaptics_i2c_rmi.c
   9  *      Copyright (C) 2007 Google, Inc.
  10  *
  11  * This software is licensed under the terms of the GNU General Public
  12  * License version 2, as published by the Free Software Foundation, and
  13  * may be copied, distributed, and modified under those terms.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  */
  20
  21 #include <linux/delay.h>
  22 #include <linux/i2c.h>
  23 #include <linux/input.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/module.h>
  26 #include <linux/pm_qos.h>
  27 #include <linux/slab.h>
  28 #include <linux/types.h>
  29
  30 #define ST1232_TS_NAME  "st1232-ts"
  31
  32 #define MIN_X           0x00
  33 #define MIN_Y           0x00
  34 #define MAX_X           0x31f   /* (800 - 1) */
  35 #define MAX_Y           0x1df   /* (480 - 1) */
  36 #define MAX_AREA        0xff
  37 #define MAX_FINGERS     2
  38
  39 struct st1232_ts_finger {
  40         u16 x;
  41         u16 y;
  42         u8 t;
  43         bool is_valid;
  44 };
  45
  46 struct st1232_ts_data {
  47         struct i2c_client *client;
  48         struct input_dev *input_dev;
  49         struct st1232_ts_finger finger[MAX_FINGERS];
  50         struct dev_pm_qos_request low_latency_req;
  51 };
  52
  53 static int st1232_ts_read_data(struct st1232_ts_data *ts)
  54 {
  55         struct st1232_ts_finger *finger = ts->finger;
  56         struct i2c_client *client = ts->client;
  57         struct i2c_msg msg[2];
  58         int error;
  59         u8 start_reg;
  60         u8 buf[10];
  61
  62         /* read touchscreen data from ST1232 */
  63         msg[0].addr = client->addr;
  64         msg[0].flags = 0;
  65         msg[0].len = 1;
  66         msg[0].buf = &start_reg;
  67         start_reg = 0x10;
  68
  69         msg[1].addr = ts->client->addr;
  70         msg[1].flags = I2C_M_RD;
  71         msg[1].len = sizeof(buf);
  72         msg[1].buf = buf;
  73
  74         error = i2c_transfer(client->adapter, msg, 2);
  75         if (error < 0)
  76                 return error;
  77
  78         /* get "valid" bits */
  79         finger[0].is_valid = buf[2] >> 7;
  80         finger[1].is_valid = buf[5] >> 7;
  81
  82         /* get xy coordinate */
  83         if (finger[0].is_valid) {
  84                 finger[0].x = ((buf[2] & 0x0070) << 4) | buf[3];
  85                 finger[0].y = ((buf[2] & 0x0007) << 8) | buf[4];
  86                 finger[0].t = buf[8];
  87         }
  88
  89         if (finger[1].is_valid) {
  90                 finger[1].x = ((buf[5] & 0x0070) << 4) | buf[6];
  91                 finger[1].y = ((buf[5] & 0x0007) << 8) | buf[7];
  92                 finger[1].t = buf[9];
  93         }
  94
  95         return 0;
  96 }
  97
  98 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
  99 {
 100         struct st1232_ts_data *ts = dev_id;
 101         struct st1232_ts_finger *finger = ts->finger;
 102         struct input_dev *input_dev = ts->input_dev;
 103         int count = 0;
 104         int i, ret;
 105
 106         ret = st1232_ts_read_data(ts);
 107         if (ret < 0)
 108                 goto end;
 109
 110         /* multi touch protocol */
 111         for (i = 0; i < MAX_FINGERS; i++) {
 112                 if (!finger[i].is_valid)
 113                         continue;
 114
 115                 input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, finger[i].t);
 116                 input_report_abs(input_dev, ABS_MT_POSITION_X, finger[i].x);
 117                 input_report_abs(input_dev, ABS_MT_POSITION_Y, finger[i].y);
 118                 input_mt_sync(input_dev);
 119                 count++;
 120         }
 121
 122         /* SYN_MT_REPORT only if no contact */
 123         if (!count) {
 124                 input_mt_sync(input_dev);
 125                 if (ts->low_latency_req.dev) {
 126                         dev_pm_qos_remove_request(&ts->low_latency_req);
 127                         ts->low_latency_req.dev = NULL;
 128                 }
 129         } else if (!ts->low_latency_req.dev) {
 130                 /* First contact, request 100 us latency. */
 131                 dev_pm_qos_add_ancestor_request(&ts->client->dev,
 132                                                 &ts->low_latency_req, 100);
 133         }
 134
 135         /* SYN_REPORT */
 136         input_sync(input_dev);
 137
 138 end:
 139         return IRQ_HANDLED;
 140 }
 141
 142 static int __devinit st1232_ts_probe(struct i2c_client *client,
 143                                         const struct i2c_device_id *id)
 144 {
 145         struct st1232_ts_data *ts;
 146         struct input_dev *input_dev;
 147         int error;
 148
 149         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 150                 dev_err(&client->dev, "need I2C_FUNC_I2C\n");
 151                 return -EIO;
 152         }
 153
 154         if (!client->irq) {
 155                 dev_err(&client->dev, "no IRQ?\n");
 156                 return -EINVAL;
 157         }
 158
 159
 160         ts = kzalloc(sizeof(struct st1232_ts_data), GFP_KERNEL);
 161         input_dev = input_allocate_device();
 162         if (!ts || !input_dev) {
 163                 error = -ENOMEM;
 164                 goto err_free_mem;
 165         }
 166
 167         ts->client = client;
 168         ts->input_dev = input_dev;
 169
 170         input_dev->name = "st1232-touchscreen";
 171         input_dev->id.bustype = BUS_I2C;
 172         input_dev->dev.parent = &client->dev;
 173
 174         __set_bit(EV_SYN, input_dev->evbit);
 175         __set_bit(EV_KEY, input_dev->evbit);
 176         __set_bit(EV_ABS, input_dev->evbit);
 177
 178         input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, MAX_AREA, 0, 0);
 179         input_set_abs_params(input_dev, ABS_MT_POSITION_X, MIN_X, MAX_X, 0, 0);
 180         input_set_abs_params(input_dev, ABS_MT_POSITION_Y, MIN_Y, MAX_Y, 0, 0);
 181
 182         error = request_threaded_irq(client->irq, NULL, st1232_ts_irq_handler,
 183                                      IRQF_ONESHOT, client->name, ts);
 184         if (error) {
 185                 dev_err(&client->dev, "Failed to register interrupt\n");
 186                 goto err_free_mem;
 187         }
 188
 189         error = input_register_device(ts->input_dev);
 190         if (error) {
 191                 dev_err(&client->dev, "Unable to register %s input device\n",
 192                         input_dev->name);
 193                 goto err_free_irq;
 194         }
 195
 196         i2c_set_clientdata(client, ts);
 197         device_init_wakeup(&client->dev, 1);
 198
 199         return 0;
 200
 201 err_free_irq:
 202         free_irq(client->irq, ts);
 203 err_free_mem:
 204         input_free_device(input_dev);
 205         kfree(ts);
 206         return error;
 207 }
 208
 209 static int __devexit st1232_ts_remove(struct i2c_client *client)
 210 {
 211         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 212
 213         device_init_wakeup(&client->dev, 0);
 214         free_irq(client->irq, ts);
 215         input_unregister_device(ts->input_dev);
 216         kfree(ts);
 217
 218         return 0;
 219 }
 220
 221 #ifdef CONFIG_PM
 222 static int st1232_ts_suspend(struct device *dev)
 223 {
 224         struct i2c_client *client = to_i2c_client(dev);
 225
 226         if (device_may_wakeup(&client->dev))
 227                 enable_irq_wake(client->irq);
 228         else
 229                 disable_irq(client->irq);
 230
 231         return 0;
 232 }
 233
 234 static int st1232_ts_resume(struct device *dev)
 235 {
 236         struct i2c_client *client = to_i2c_client(dev);
 237
 238         if (device_may_wakeup(&client->dev))
 239                 disable_irq_wake(client->irq);
 240         else
 241                 enable_irq(client->irq);
 242
 243         return 0;
 244 }
 245
 246 static const struct dev_pm_ops st1232_ts_pm_ops = {
 247         .suspend        = st1232_ts_suspend,
 248         .resume         = st1232_ts_resume,
 249 };
 250 #endif
 251
 252 static const struct i2c_device_id st1232_ts_id[] = {
 253         { ST1232_TS_NAME, 0 },
 254         { }
 255 };
 256 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
 257
 258 static struct i2c_driver st1232_ts_driver = {
 259         .probe          = st1232_ts_probe,
 260         .remove         = __devexit_p(st1232_ts_remove),
 261         .id_table       = st1232_ts_id,
 262         .driver = {
 263                 .name   = ST1232_TS_NAME,
 264                 .owner  = THIS_MODULE,
 265 #ifdef CONFIG_PM
 266                 .pm     = &st1232_ts_pm_ops,
 267 #endif
 268         },
 269 };
 270
 271 static int __init st1232_ts_init(void)
 272 {
 273         return i2c_add_driver(&st1232_ts_driver);
 274 }
 275 module_init(st1232_ts_init);
 276
 277 static void __exit st1232_ts_exit(void)
 278 {
 279         i2c_del_driver(&st1232_ts_driver);
 280 }
 281 module_exit(st1232_ts_exit);
 282
 283 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
 284 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
 285 MODULE_LICENSE("GPL");