drivers/input/touchscreen/ektf2127.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Driver for ELAN eKTF2127 i2c touchscreen controller
   4  *
   5  * For this driver the layout of the Chipone icn8318 i2c
   6  * touchscreencontroller is used.
   7  *
   8  * Author:
   9  * Michel Verlaan <michel.verl@gmail.com>
  10  * Siebren Vroegindeweij <siebren.vroegindeweij@hotmail.com>
  11  *
  12  * Original chipone_icn8318 driver:
  13  * Hans de Goede <hdegoede@redhat.com>
  14  */
  15
  16 #include <linux/bits.h>
  17 #include <linux/gpio/consumer.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/i2c.h>
  20 #include <linux/input.h>
  21 #include <linux/input/mt.h>
  22 #include <linux/input/touchscreen.h>
  23 #include <linux/module.h>
  24 #include <linux/of.h>
  25 #include <linux/delay.h>
  26
  27 /* Packet header defines (first byte of data send / received) */
  28 #define EKTF2127_NOISE                  0x40
  29 #define EKTF2127_RESPONSE               0x52
  30 #define EKTF2127_REQUEST                0x53
  31 #define EKTF2127_HELLO                  0x55
  32 #define EKTF2127_REPORT2                0x5a
  33 #define EKTF2127_REPORT                 0x5d
  34 #define EKTF2127_CALIB_DONE             0x66
  35
  36 /* Register defines (second byte of data send / received) */
  37 #define EKTF2127_ENV_NOISY              0x41
  38 #define EKTF2127_HEIGHT                 0x60
  39 #define EKTF2127_WIDTH                  0x63
  40
  41 /* 2 bytes header + 5 * 3 bytes coordinates + 3 bytes pressure info + footer */
  42 #define EKTF2127_TOUCH_REPORT_SIZE      21
  43 #define EKTF2127_MAX_TOUCHES            5
  44
  45 struct ektf2127_ts {
  46         struct i2c_client *client;
  47         struct input_dev *input;
  48         struct gpio_desc *power_gpios;
  49         struct touchscreen_properties prop;
  50         int status_shift;
  51 };
  52
  53 struct ektf2127_i2c_chip_data {
  54         int status_shift;
  55 };
  56
  57 static void ektf2127_parse_coordinates(const u8 *buf, unsigned int touch_count,
  58                                        struct input_mt_pos *touches)
  59 {
  60         int index = 0;
  61         int i;
  62
  63         for (i = 0; i < touch_count; i++) {
  64                 index = 2 + i * 3;
  65
  66                 touches[i].x = (buf[index] & 0x0f);
  67                 touches[i].x <<= 8;
  68                 touches[i].x |= buf[index + 2];
  69
  70                 touches[i].y = (buf[index] & 0xf0);
  71                 touches[i].y <<= 4;
  72                 touches[i].y |= buf[index + 1];
  73         }
  74 }
  75
  76 static void ektf2127_report_event(struct ektf2127_ts *ts, const u8 *buf)
  77 {
  78         struct input_mt_pos touches[EKTF2127_MAX_TOUCHES];
  79         int slots[EKTF2127_MAX_TOUCHES];
  80         unsigned int touch_count, i;
  81
  82         touch_count = buf[1] & 0x07;
  83         if (touch_count > EKTF2127_MAX_TOUCHES) {
  84                 dev_err(&ts->client->dev,
  85                         "Too many touches %d > %d\n",
  86                         touch_count, EKTF2127_MAX_TOUCHES);
  87                 touch_count = EKTF2127_MAX_TOUCHES;
  88         }
  89
  90         ektf2127_parse_coordinates(buf, touch_count, touches);
  91         input_mt_assign_slots(ts->input, slots, touches,
  92                               touch_count, 0);
  93
  94         for (i = 0; i < touch_count; i++) {
  95                 input_mt_slot(ts->input, slots[i]);
  96                 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
  97                 touchscreen_report_pos(ts->input, &ts->prop,
  98                                        touches[i].x, touches[i].y, true);
  99         }
 100
 101         input_mt_sync_frame(ts->input);
 102         input_sync(ts->input);
 103 }
 104
 105 static void ektf2127_report2_contact(struct ektf2127_ts *ts, int slot,
 106                                      const u8 *buf, bool active)
 107 {
 108         input_mt_slot(ts->input, slot);
 109         input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, active);
 110
 111         if (active) {
 112                 int x = (buf[0] & 0xf0) << 4 | buf[1];
 113                 int y = (buf[0] & 0x0f) << 8 | buf[2];
 114
 115                 touchscreen_report_pos(ts->input, &ts->prop, x, y, true);
 116         }
 117 }
 118
 119 static void ektf2127_report2_event(struct ektf2127_ts *ts, const u8 *buf)
 120 {
 121         ektf2127_report2_contact(ts, 0, &buf[1], !!(buf[7] & BIT(ts->status_shift)));
 122         ektf2127_report2_contact(ts, 1, &buf[4], !!(buf[7] & BIT(ts->status_shift + 1)));
 123
 124         input_mt_sync_frame(ts->input);
 125         input_sync(ts->input);
 126 }
 127
 128 static irqreturn_t ektf2127_irq(int irq, void *dev_id)
 129 {
 130         struct ektf2127_ts *ts = dev_id;
 131         struct device *dev = &ts->client->dev;
 132         char buf[EKTF2127_TOUCH_REPORT_SIZE];
 133         int ret;
 134
 135         ret = i2c_master_recv(ts->client, buf, EKTF2127_TOUCH_REPORT_SIZE);
 136         if (ret != EKTF2127_TOUCH_REPORT_SIZE) {
 137                 dev_err(dev, "Error reading touch data: %d\n", ret);
 138                 goto out;
 139         }
 140
 141         switch (buf[0]) {
 142         case EKTF2127_REPORT:
 143                 ektf2127_report_event(ts, buf);
 144                 break;
 145
 146         case EKTF2127_REPORT2:
 147                 ektf2127_report2_event(ts, buf);
 148                 break;
 149
 150         case EKTF2127_NOISE:
 151                 if (buf[1] == EKTF2127_ENV_NOISY)
 152                         dev_dbg(dev, "Environment is electrically noisy\n");
 153                 break;
 154
 155         case EKTF2127_HELLO:
 156         case EKTF2127_CALIB_DONE:
 157                 break;
 158
 159         default:
 160                 dev_err(dev, "Unexpected packet header byte %#02x\n", buf[0]);
 161                 break;
 162         }
 163
 164 out:
 165         return IRQ_HANDLED;
 166 }
 167
 168 static int ektf2127_start(struct input_dev *dev)
 169 {
 170         struct ektf2127_ts *ts = input_get_drvdata(dev);
 171
 172         enable_irq(ts->client->irq);
 173         gpiod_set_value_cansleep(ts->power_gpios, 1);
 174
 175         return 0;
 176 }
 177
 178 static void ektf2127_stop(struct input_dev *dev)
 179 {
 180         struct ektf2127_ts *ts = input_get_drvdata(dev);
 181
 182         disable_irq(ts->client->irq);
 183         gpiod_set_value_cansleep(ts->power_gpios, 0);
 184 }
 185
 186 static int ektf2127_suspend(struct device *dev)
 187 {
 188         struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev));
 189
 190         mutex_lock(&ts->input->mutex);
 191         if (input_device_enabled(ts->input))
 192                 ektf2127_stop(ts->input);
 193         mutex_unlock(&ts->input->mutex);
 194
 195         return 0;
 196 }
 197
 198 static int ektf2127_resume(struct device *dev)
 199 {
 200         struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev));
 201
 202         mutex_lock(&ts->input->mutex);
 203         if (input_device_enabled(ts->input))
 204                 ektf2127_start(ts->input);
 205         mutex_unlock(&ts->input->mutex);
 206
 207         return 0;
 208 }
 209
 210 static DEFINE_SIMPLE_DEV_PM_OPS(ektf2127_pm_ops, ektf2127_suspend,
 211                                 ektf2127_resume);
 212
 213 static int ektf2127_query_dimension(struct i2c_client *client, bool width)
 214 {
 215         struct device *dev = &client->dev;
 216         const char *what = width ? "width" : "height";
 217         u8 what_code = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT;
 218         u8 buf[4];
 219         int ret;
 220         int error;
 221
 222         /* Request dimension */
 223         buf[0] = EKTF2127_REQUEST;
 224         buf[1] = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT;
 225         buf[2] = 0x00;
 226         buf[3] = 0x00;
 227         ret = i2c_master_send(client, buf, sizeof(buf));
 228         if (ret != sizeof(buf)) {
 229                 error = ret < 0 ? ret : -EIO;
 230                 dev_err(dev, "Failed to request %s: %d\n", what, error);
 231                 return error;
 232         }
 233
 234         msleep(20);
 235
 236         /* Read response */
 237         ret = i2c_master_recv(client, buf, sizeof(buf));
 238         if (ret != sizeof(buf)) {
 239                 error = ret < 0 ? ret : -EIO;
 240                 dev_err(dev, "Failed to receive %s data: %d\n", what, error);
 241                 return error;
 242         }
 243
 244         if (buf[0] != EKTF2127_RESPONSE || buf[1] != what_code) {
 245                 dev_err(dev, "Unexpected %s data: %#02x %#02x\n",
 246                         what, buf[0], buf[1]);
 247                 return -EIO;
 248         }
 249
 250         return (((buf[3] & 0xf0) << 4) | buf[2]) - 1;
 251 }
 252
 253 static int ektf2127_probe(struct i2c_client *client)
 254 {
 255         struct device *dev = &client->dev;
 256         const struct ektf2127_i2c_chip_data *chip_data;
 257         struct ektf2127_ts *ts;
 258         struct input_dev *input;
 259         u8 buf[4];
 260         int max_x, max_y;
 261         int error;
 262
 263         if (!client->irq) {
 264                 dev_err(dev, "Error no irq specified\n");
 265                 return -EINVAL;
 266         }
 267
 268         ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
 269         if (!ts)
 270                 return -ENOMEM;
 271
 272         /* This requests the gpio *and* turns on the touchscreen controller */
 273         ts->power_gpios = devm_gpiod_get(dev, "power", GPIOD_OUT_HIGH);
 274         if (IS_ERR(ts->power_gpios))
 275                 return dev_err_probe(dev, PTR_ERR(ts->power_gpios), "Error getting power gpio\n");
 276
 277         input = devm_input_allocate_device(dev);
 278         if (!input)
 279                 return -ENOMEM;
 280
 281         input->name = client->name;
 282         input->id.bustype = BUS_I2C;
 283         input->open = ektf2127_start;
 284         input->close = ektf2127_stop;
 285
 286         ts->client = client;
 287
 288         /* Read hello (ignore result, depends on initial power state) */
 289         msleep(20);
 290         i2c_master_recv(ts->client, buf, sizeof(buf));
 291
 292         /* Read resolution from chip */
 293         max_x = ektf2127_query_dimension(client, true);
 294         if (max_x < 0)
 295                 return max_x;
 296
 297         max_y = ektf2127_query_dimension(client, false);
 298         if (max_y < 0)
 299                 return max_y;
 300
 301         input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
 302         input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
 303         touchscreen_parse_properties(input, true, &ts->prop);
 304
 305         error = input_mt_init_slots(input, EKTF2127_MAX_TOUCHES,
 306                                     INPUT_MT_DIRECT |
 307                                         INPUT_MT_DROP_UNUSED |
 308                                         INPUT_MT_TRACK);
 309         if (error)
 310                 return error;
 311
 312         ts->input = input;
 313
 314         chip_data = i2c_get_match_data(client);
 315         if (!chip_data)
 316                 return dev_err_probe(&client->dev, -EINVAL, "missing chip data\n");
 317
 318         ts->status_shift = chip_data->status_shift;
 319
 320         input_set_drvdata(input, ts);
 321
 322         error = devm_request_threaded_irq(dev, client->irq,
 323                                           NULL, ektf2127_irq,
 324                                           IRQF_ONESHOT, client->name, ts);
 325         if (error) {
 326                 dev_err(dev, "Error requesting irq: %d\n", error);
 327                 return error;
 328         }
 329
 330         /* Stop device till opened */
 331         ektf2127_stop(ts->input);
 332
 333         error = input_register_device(input);
 334         if (error)
 335                 return error;
 336
 337         i2c_set_clientdata(client, ts);
 338
 339         return 0;
 340 }
 341
 342 static const struct ektf2127_i2c_chip_data ektf2127_data = {
 343         .status_shift = 1,
 344 };
 345
 346 static const struct ektf2127_i2c_chip_data ektf2232_data = {
 347         .status_shift = 0,
 348 };
 349
 350 #ifdef CONFIG_OF
 351 static const struct of_device_id ektf2127_of_match[] = {
 352         { .compatible = "elan,ektf2127", .data = &ektf2127_data},
 353         { .compatible = "elan,ektf2132", .data = &ektf2127_data},
 354         { .compatible = "elan,ektf2232", .data = &ektf2232_data},
 355         {}
 356 };
 357 MODULE_DEVICE_TABLE(of, ektf2127_of_match);
 358 #endif
 359
 360 static const struct i2c_device_id ektf2127_i2c_id[] = {
 361         { .name = "ektf2127", .driver_data = (long)&ektf2127_data },
 362         { .name = "ektf2132", .driver_data = (long)&ektf2127_data },
 363         { .name = "ektf2232", .driver_data = (long)&ektf2232_data },
 364         {}
 365 };
 366 MODULE_DEVICE_TABLE(i2c, ektf2127_i2c_id);
 367
 368 static struct i2c_driver ektf2127_driver = {
 369         .driver = {
 370                 .name   = "elan_ektf2127",
 371                 .pm     = pm_sleep_ptr(&ektf2127_pm_ops),
 372                 .of_match_table = of_match_ptr(ektf2127_of_match),
 373         },
 374         .probe = ektf2127_probe,
 375         .id_table = ektf2127_i2c_id,
 376 };
 377 module_i2c_driver(ektf2127_driver);
 378
 379 MODULE_DESCRIPTION("ELAN eKTF2127/eKTF2132 I2C Touchscreen Driver");
 380 MODULE_AUTHOR("Michel Verlaan, Siebren Vroegindeweij");
 381 MODULE_LICENSE("GPL");