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