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/gpio.h>
  23 #include <linux/i2c.h>
  24 #include <linux/input.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/module.h>
  27 #include <linux/of.h>
  28 #include <linux/of_gpio.h>
  29 #include <linux/pm_qos.h>
  30 #include <linux/slab.h>
  31 #include <linux/types.h>
  32 #include <linux/platform_data/st1232_pdata.h>
  33
  34 #define ST1232_TS_NAME  "st1232-ts"
  35
  36 #define MIN_X           0x00
  37 #define MIN_Y           0x00
  38 #define MAX_X           0x31f   /* (800 - 1) */
  39 #define MAX_Y           0x1df   /* (480 - 1) */
  40 #define MAX_AREA        0xff
  41 #define MAX_FINGERS     2
  42
  43 struct st1232_ts_finger {
  44         u16 x;
  45         u16 y;
  46         u8 t;
  47         bool is_valid;
  48 };
  49
  50 struct st1232_ts_data {
  51         struct i2c_client *client;
  52         struct input_dev *input_dev;
  53         struct st1232_ts_finger finger[MAX_FINGERS];
  54         struct dev_pm_qos_request low_latency_req;
  55         int reset_gpio;
  56 };
  57
  58 static int st1232_ts_read_data(struct st1232_ts_data *ts)
  59 {
  60         struct st1232_ts_finger *finger = ts->finger;
  61         struct i2c_client *client = ts->client;
  62         struct i2c_msg msg[2];
  63         int error;
  64         u8 start_reg;
  65         u8 buf[10];
  66
  67         /* read touchscreen data from ST1232 */
  68         msg[0].addr = client->addr;
  69         msg[0].flags = 0;
  70         msg[0].len = 1;
  71         msg[0].buf = &start_reg;
  72         start_reg = 0x10;
  73
  74         msg[1].addr = ts->client->addr;
  75         msg[1].flags = I2C_M_RD;
  76         msg[1].len = sizeof(buf);
  77         msg[1].buf = buf;
  78
  79         error = i2c_transfer(client->adapter, msg, 2);
  80         if (error < 0)
  81                 return error;
  82
  83         /* get "valid" bits */
  84         finger[0].is_valid = buf[2] >> 7;
  85         finger[1].is_valid = buf[5] >> 7;
  86
  87         /* get xy coordinate */
  88         if (finger[0].is_valid) {
  89                 finger[0].x = ((buf[2] & 0x0070) << 4) | buf[3];
  90                 finger[0].y = ((buf[2] & 0x0007) << 8) | buf[4];
  91                 finger[0].t = buf[8];
  92         }
  93
  94         if (finger[1].is_valid) {
  95                 finger[1].x = ((buf[5] & 0x0070) << 4) | buf[6];
  96                 finger[1].y = ((buf[5] & 0x0007) << 8) | buf[7];
  97                 finger[1].t = buf[9];
  98         }
  99
 100         return 0;
 101 }
 102
 103 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
 104 {
 105         struct st1232_ts_data *ts = dev_id;
 106         struct st1232_ts_finger *finger = ts->finger;
 107         struct input_dev *input_dev = ts->input_dev;
 108         int count = 0;
 109         int i, ret;
 110
 111         ret = st1232_ts_read_data(ts);
 112         if (ret < 0)
 113                 goto end;
 114
 115         /* multi touch protocol */
 116         for (i = 0; i < MAX_FINGERS; i++) {
 117                 if (!finger[i].is_valid)
 118                         continue;
 119
 120                 input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, finger[i].t);
 121                 input_report_abs(input_dev, ABS_MT_POSITION_X, finger[i].x);
 122                 input_report_abs(input_dev, ABS_MT_POSITION_Y, finger[i].y);
 123                 input_mt_sync(input_dev);
 124                 count++;
 125         }
 126
 127         /* SYN_MT_REPORT only if no contact */
 128         if (!count) {
 129                 input_mt_sync(input_dev);
 130                 if (ts->low_latency_req.dev) {
 131                         dev_pm_qos_remove_request(&ts->low_latency_req);
 132                         ts->low_latency_req.dev = NULL;
 133                 }
 134         } else if (!ts->low_latency_req.dev) {
 135                 /* First contact, request 100 us latency. */
 136                 dev_pm_qos_add_ancestor_request(&ts->client->dev,
 137                                                 &ts->low_latency_req,
 138                                                 DEV_PM_QOS_RESUME_LATENCY, 100);
 139         }
 140
 141         /* SYN_REPORT */
 142         input_sync(input_dev);
 143
 144 end:
 145         return IRQ_HANDLED;
 146 }
 147
 148 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
 149 {
 150         if (gpio_is_valid(ts->reset_gpio))
 151                 gpio_direction_output(ts->reset_gpio, poweron);
 152 }
 153
 154 static int st1232_ts_probe(struct i2c_client *client,
 155                                         const struct i2c_device_id *id)
 156 {
 157         struct st1232_ts_data *ts;
 158         struct st1232_pdata *pdata = dev_get_platdata(&client->dev);
 159         struct input_dev *input_dev;
 160         int error;
 161
 162         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 163                 dev_err(&client->dev, "need I2C_FUNC_I2C\n");
 164                 return -EIO;
 165         }
 166
 167         if (!client->irq) {
 168                 dev_err(&client->dev, "no IRQ?\n");
 169                 return -EINVAL;
 170         }
 171
 172         ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
 173         if (!ts)
 174                 return -ENOMEM;
 175
 176         input_dev = devm_input_allocate_device(&client->dev);
 177         if (!input_dev)
 178                 return -ENOMEM;
 179
 180         ts->client = client;
 181         ts->input_dev = input_dev;
 182
 183         if (pdata)
 184                 ts->reset_gpio = pdata->reset_gpio;
 185         else if (client->dev.of_node)
 186                 ts->reset_gpio = of_get_gpio(client->dev.of_node, 0);
 187         else
 188                 ts->reset_gpio = -ENODEV;
 189
 190         if (gpio_is_valid(ts->reset_gpio)) {
 191                 error = devm_gpio_request(&client->dev, ts->reset_gpio, NULL);
 192                 if (error) {
 193                         dev_err(&client->dev,
 194                                 "Unable to request GPIO pin %d.\n",
 195                                 ts->reset_gpio);
 196                                 return error;
 197                 }
 198         }
 199
 200         st1232_ts_power(ts, true);
 201
 202         input_dev->name = "st1232-touchscreen";
 203         input_dev->id.bustype = BUS_I2C;
 204         input_dev->dev.parent = &client->dev;
 205
 206         __set_bit(EV_SYN, input_dev->evbit);
 207         __set_bit(EV_KEY, input_dev->evbit);
 208         __set_bit(EV_ABS, input_dev->evbit);
 209
 210         input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, MAX_AREA, 0, 0);
 211         input_set_abs_params(input_dev, ABS_MT_POSITION_X, MIN_X, MAX_X, 0, 0);
 212         input_set_abs_params(input_dev, ABS_MT_POSITION_Y, MIN_Y, MAX_Y, 0, 0);
 213
 214         error = devm_request_threaded_irq(&client->dev, client->irq,
 215                                           NULL, st1232_ts_irq_handler,
 216                                           IRQF_ONESHOT,
 217                                           client->name, ts);
 218         if (error) {
 219                 dev_err(&client->dev, "Failed to register interrupt\n");
 220                 return error;
 221         }
 222
 223         error = input_register_device(ts->input_dev);
 224         if (error) {
 225                 dev_err(&client->dev, "Unable to register %s input device\n",
 226                         input_dev->name);
 227                 return error;
 228         }
 229
 230         i2c_set_clientdata(client, ts);
 231         device_init_wakeup(&client->dev, 1);
 232
 233         return 0;
 234 }
 235
 236 static int st1232_ts_remove(struct i2c_client *client)
 237 {
 238         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 239
 240         device_init_wakeup(&client->dev, 0);
 241         st1232_ts_power(ts, false);
 242
 243         return 0;
 244 }
 245
 246 static int __maybe_unused st1232_ts_suspend(struct device *dev)
 247 {
 248         struct i2c_client *client = to_i2c_client(dev);
 249         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 250
 251         if (device_may_wakeup(&client->dev)) {
 252                 enable_irq_wake(client->irq);
 253         } else {
 254                 disable_irq(client->irq);
 255                 st1232_ts_power(ts, false);
 256         }
 257
 258         return 0;
 259 }
 260
 261 static int __maybe_unused st1232_ts_resume(struct device *dev)
 262 {
 263         struct i2c_client *client = to_i2c_client(dev);
 264         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 265
 266         if (device_may_wakeup(&client->dev)) {
 267                 disable_irq_wake(client->irq);
 268         } else {
 269                 st1232_ts_power(ts, true);
 270                 enable_irq(client->irq);
 271         }
 272
 273         return 0;
 274 }
 275
 276 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
 277                          st1232_ts_suspend, st1232_ts_resume);
 278
 279 static const struct i2c_device_id st1232_ts_id[] = {
 280         { ST1232_TS_NAME, 0 },
 281         { }
 282 };
 283 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
 284
 285 #ifdef CONFIG_OF
 286 static const struct of_device_id st1232_ts_dt_ids[] = {
 287         { .compatible = "sitronix,st1232", },
 288         { }
 289 };
 290 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
 291 #endif
 292
 293 static struct i2c_driver st1232_ts_driver = {
 294         .probe          = st1232_ts_probe,
 295         .remove         = st1232_ts_remove,
 296         .id_table       = st1232_ts_id,
 297         .driver = {
 298                 .name   = ST1232_TS_NAME,
 299                 .owner  = THIS_MODULE,
 300                 .of_match_table = of_match_ptr(st1232_ts_dt_ids),
 301                 .pm     = &st1232_ts_pm_ops,
 302         },
 303 };
 304
 305 module_i2c_driver(st1232_ts_driver);
 306
 307 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
 308 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
 309 MODULE_LICENSE("GPL");