drivers/input/touchscreen/imagis.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 #include <linux/bitfield.h>
   4 #include <linux/bits.h>
   5 #include <linux/delay.h>
   6 #include <linux/i2c.h>
   7 #include <linux/input.h>
   8 #include <linux/input/mt.h>
   9 #include <linux/input/touchscreen.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/property.h>
  13 #include <linux/regulator/consumer.h>
  14
  15 #define IST3032C_WHOAMI                 0x32c
  16
  17 #define IST3038B_REG_STATUS             0x20
  18 #define IST3038B_REG_CHIPID             0x30
  19 #define IST3038B_WHOAMI                 0x30380b
  20
  21 #define IST3038C_HIB_ACCESS             (0x800B << 16)
  22 #define IST3038C_DIRECT_ACCESS          BIT(31)
  23 #define IST3038C_REG_CHIPID             (0x40001000 | IST3038C_DIRECT_ACCESS)
  24 #define IST3038C_REG_HIB_BASE           0x30000100
  25 #define IST3038C_REG_TOUCH_STATUS       (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS)
  26 #define IST3038C_REG_TOUCH_COORD        (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x8)
  27 #define IST3038C_REG_INTR_MESSAGE       (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x4)
  28 #define IST3038C_WHOAMI                 0x38c
  29 #define IST3038C_CHIP_ON_DELAY_MS       60
  30 #define IST3038C_I2C_RETRY_COUNT        3
  31 #define IST3038C_MAX_FINGER_NUM         10
  32 #define IST3038C_X_MASK                 GENMASK(23, 12)
  33 #define IST3038C_Y_MASK                 GENMASK(11, 0)
  34 #define IST3038C_AREA_MASK              GENMASK(27, 24)
  35 #define IST3038C_FINGER_COUNT_MASK      GENMASK(15, 12)
  36 #define IST3038C_FINGER_STATUS_MASK     GENMASK(9, 0)
  37 #define IST3032C_KEY_STATUS_MASK        GENMASK(20, 16)
  38
  39 struct imagis_properties {
  40         unsigned int interrupt_msg_cmd;
  41         unsigned int touch_coord_cmd;
  42         unsigned int whoami_cmd;
  43         unsigned int whoami_val;
  44         bool protocol_b;
  45         bool touch_keys_supported;
  46 };
  47
  48 struct imagis_ts {
  49         struct i2c_client *client;
  50         const struct imagis_properties *tdata;
  51         struct input_dev *input_dev;
  52         struct touchscreen_properties prop;
  53         struct regulator_bulk_data supplies[2];
  54         u32 keycodes[5];
  55         int num_keycodes;
  56 };
  57
  58 static int imagis_i2c_read_reg(struct imagis_ts *ts,
  59                                unsigned int reg, u32 *data)
  60 {
  61         __be32 ret_be;
  62         __be32 reg_be = cpu_to_be32(reg);
  63         struct i2c_msg msg[] = {
  64                 {
  65                         .addr = ts->client->addr,
  66                         .flags = 0,
  67                         .buf = (unsigned char *)&reg_be,
  68                         .len = sizeof(reg_be),
  69                 }, {
  70                         .addr = ts->client->addr,
  71                         .flags = I2C_M_RD,
  72                         .buf = (unsigned char *)&ret_be,
  73                         .len = sizeof(ret_be),
  74                 },
  75         };
  76         int ret, error;
  77         int retry = IST3038C_I2C_RETRY_COUNT;
  78
  79         /* Retry in case the controller fails to respond */
  80         do {
  81                 ret = i2c_transfer(ts->client->adapter, msg, ARRAY_SIZE(msg));
  82                 if (ret == ARRAY_SIZE(msg)) {
  83                         *data = be32_to_cpu(ret_be);
  84                         return 0;
  85                 }
  86
  87                 error = ret < 0 ? ret : -EIO;
  88                 dev_err(&ts->client->dev,
  89                         "%s - i2c_transfer failed: %d (%d)\n",
  90                         __func__, error, ret);
  91         } while (--retry);
  92
  93         return error;
  94 }
  95
  96 static irqreturn_t imagis_interrupt(int irq, void *dev_id)
  97 {
  98         struct imagis_ts *ts = dev_id;
  99         u32 intr_message, finger_status;
 100         unsigned int finger_count, finger_pressed, key_pressed;
 101         int i;
 102         int error;
 103
 104         error = imagis_i2c_read_reg(ts, ts->tdata->interrupt_msg_cmd, &intr_message);
 105         if (error) {
 106                 dev_err(&ts->client->dev,
 107                         "failed to read the interrupt message: %d\n", error);
 108                 goto out;
 109         }
 110
 111         finger_count = FIELD_GET(IST3038C_FINGER_COUNT_MASK, intr_message);
 112         if (finger_count > IST3038C_MAX_FINGER_NUM) {
 113                 dev_err(&ts->client->dev,
 114                         "finger count %d is more than maximum supported\n",
 115                         finger_count);
 116                 goto out;
 117         }
 118
 119         finger_pressed = FIELD_GET(IST3038C_FINGER_STATUS_MASK, intr_message);
 120
 121         for (i = 0; i < finger_count; i++) {
 122                 if (ts->tdata->protocol_b)
 123                         error = imagis_i2c_read_reg(ts,
 124                                                     ts->tdata->touch_coord_cmd, &finger_status);
 125                 else
 126                         error = imagis_i2c_read_reg(ts,
 127                                                     ts->tdata->touch_coord_cmd + (i * 4),
 128                                                     &finger_status);
 129                 if (error) {
 130                         dev_err(&ts->client->dev,
 131                                 "failed to read coordinates for finger %d: %d\n",
 132                                 i, error);
 133                         goto out;
 134                 }
 135
 136                 input_mt_slot(ts->input_dev, i);
 137                 input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER,
 138                                            finger_pressed & BIT(i));
 139                 touchscreen_report_pos(ts->input_dev, &ts->prop,
 140                                        FIELD_GET(IST3038C_X_MASK, finger_status),
 141                                        FIELD_GET(IST3038C_Y_MASK, finger_status),
 142                                        true);
 143                 input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR,
 144                                  FIELD_GET(IST3038C_AREA_MASK, finger_status));
 145         }
 146
 147         key_pressed = FIELD_GET(IST3032C_KEY_STATUS_MASK, intr_message);
 148
 149         for (int i = 0; i < ts->num_keycodes; i++)
 150                 input_report_key(ts->input_dev, ts->keycodes[i],
 151                                  key_pressed & BIT(i));
 152
 153         input_mt_sync_frame(ts->input_dev);
 154         input_sync(ts->input_dev);
 155
 156 out:
 157         return IRQ_HANDLED;
 158 }
 159
 160 static void imagis_power_off(void *_ts)
 161 {
 162         struct imagis_ts *ts = _ts;
 163
 164         regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
 165 }
 166
 167 static int imagis_power_on(struct imagis_ts *ts)
 168 {
 169         int error;
 170
 171         error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
 172         if (error)
 173                 return error;
 174
 175         msleep(IST3038C_CHIP_ON_DELAY_MS);
 176
 177         return 0;
 178 }
 179
 180 static int imagis_start(struct imagis_ts *ts)
 181 {
 182         int error;
 183
 184         error = imagis_power_on(ts);
 185         if (error)
 186                 return error;
 187
 188         enable_irq(ts->client->irq);
 189
 190         return 0;
 191 }
 192
 193 static int imagis_stop(struct imagis_ts *ts)
 194 {
 195         disable_irq(ts->client->irq);
 196
 197         imagis_power_off(ts);
 198
 199         return 0;
 200 }
 201
 202 static int imagis_input_open(struct input_dev *dev)
 203 {
 204         struct imagis_ts *ts = input_get_drvdata(dev);
 205
 206         return imagis_start(ts);
 207 }
 208
 209 static void imagis_input_close(struct input_dev *dev)
 210 {
 211         struct imagis_ts *ts = input_get_drvdata(dev);
 212
 213         imagis_stop(ts);
 214 }
 215
 216 static int imagis_init_input_dev(struct imagis_ts *ts)
 217 {
 218         struct input_dev *input_dev;
 219         int error;
 220
 221         input_dev = devm_input_allocate_device(&ts->client->dev);
 222         if (!input_dev)
 223                 return -ENOMEM;
 224
 225         ts->input_dev = input_dev;
 226
 227         input_dev->name = "Imagis capacitive touchscreen";
 228         input_dev->phys = "input/ts";
 229         input_dev->id.bustype = BUS_I2C;
 230         input_dev->open = imagis_input_open;
 231         input_dev->close = imagis_input_close;
 232
 233         input_set_drvdata(input_dev, ts);
 234
 235         input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
 236         input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
 237         input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 16, 0, 0);
 238         if (ts->tdata->touch_keys_supported) {
 239                 ts->num_keycodes = of_property_read_variable_u32_array(
 240                                 ts->client->dev.of_node, "linux,keycodes",
 241                                 ts->keycodes, 0, ARRAY_SIZE(ts->keycodes));
 242                 if (ts->num_keycodes <= 0) {
 243                         ts->keycodes[0] = KEY_APPSELECT;
 244                         ts->keycodes[1] = KEY_BACK;
 245                         ts->num_keycodes = 2;
 246                 }
 247
 248                 input_dev->keycodemax = ts->num_keycodes;
 249                 input_dev->keycodesize = sizeof(ts->keycodes[0]);
 250                 input_dev->keycode = ts->keycodes;
 251         }
 252
 253         for (int i = 0; i < ts->num_keycodes; i++)
 254                 input_set_capability(input_dev, EV_KEY, ts->keycodes[i]);
 255
 256         touchscreen_parse_properties(input_dev, true, &ts->prop);
 257         if (!ts->prop.max_x || !ts->prop.max_y) {
 258                 dev_err(&ts->client->dev,
 259                         "Touchscreen-size-x and/or touchscreen-size-y not set in dts\n");
 260                 return -EINVAL;
 261         }
 262
 263         error = input_mt_init_slots(input_dev,
 264                                     IST3038C_MAX_FINGER_NUM,
 265                                     INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 266         if (error) {
 267                 dev_err(&ts->client->dev,
 268                         "Failed to initialize MT slots: %d", error);
 269                 return error;
 270         }
 271
 272         error = input_register_device(input_dev);
 273         if (error) {
 274                 dev_err(&ts->client->dev,
 275                         "Failed to register input device: %d", error);
 276                 return error;
 277         }
 278
 279         return 0;
 280 }
 281
 282 static int imagis_init_regulators(struct imagis_ts *ts)
 283 {
 284         struct i2c_client *client = ts->client;
 285
 286         ts->supplies[0].supply = "vdd";
 287         ts->supplies[1].supply = "vddio";
 288         return devm_regulator_bulk_get(&client->dev,
 289                                        ARRAY_SIZE(ts->supplies),
 290                                        ts->supplies);
 291 }
 292
 293 static int imagis_probe(struct i2c_client *i2c)
 294 {
 295         struct device *dev = &i2c->dev;
 296         struct imagis_ts *ts;
 297         int chip_id, error;
 298
 299         ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
 300         if (!ts)
 301                 return -ENOMEM;
 302
 303         ts->client = i2c;
 304
 305         ts->tdata = device_get_match_data(dev);
 306         if (!ts->tdata) {
 307                 dev_err(dev, "missing chip data\n");
 308                 return -EINVAL;
 309         }
 310
 311         error = imagis_init_regulators(ts);
 312         if (error) {
 313                 dev_err(dev, "regulator init error: %d\n", error);
 314                 return error;
 315         }
 316
 317         error = imagis_power_on(ts);
 318         if (error) {
 319                 dev_err(dev, "failed to enable regulators: %d\n", error);
 320                 return error;
 321         }
 322
 323         error = devm_add_action_or_reset(dev, imagis_power_off, ts);
 324         if (error) {
 325                 dev_err(dev, "failed to install poweroff action: %d\n", error);
 326                 return error;
 327         }
 328
 329         error = imagis_i2c_read_reg(ts, ts->tdata->whoami_cmd, &chip_id);
 330         if (error) {
 331                 dev_err(dev, "chip ID read failure: %d\n", error);
 332                 return error;
 333         }
 334
 335         if (chip_id != ts->tdata->whoami_val) {
 336                 dev_err(dev, "unknown chip ID: 0x%x\n", chip_id);
 337                 return -EINVAL;
 338         }
 339
 340         error = devm_request_threaded_irq(dev, i2c->irq,
 341                                           NULL, imagis_interrupt,
 342                                           IRQF_ONESHOT | IRQF_NO_AUTOEN,
 343                                           "imagis-touchscreen", ts);
 344         if (error) {
 345                 dev_err(dev, "IRQ %d allocation failure: %d\n",
 346                         i2c->irq, error);
 347                 return error;
 348         }
 349
 350         error = imagis_init_input_dev(ts);
 351         if (error)
 352                 return error;
 353
 354         return 0;
 355 }
 356
 357 static int imagis_suspend(struct device *dev)
 358 {
 359         struct i2c_client *client = to_i2c_client(dev);
 360         struct imagis_ts *ts = i2c_get_clientdata(client);
 361         int retval = 0;
 362
 363         mutex_lock(&ts->input_dev->mutex);
 364
 365         if (input_device_enabled(ts->input_dev))
 366                 retval = imagis_stop(ts);
 367
 368         mutex_unlock(&ts->input_dev->mutex);
 369
 370         return retval;
 371 }
 372
 373 static int imagis_resume(struct device *dev)
 374 {
 375         struct i2c_client *client = to_i2c_client(dev);
 376         struct imagis_ts *ts = i2c_get_clientdata(client);
 377         int retval = 0;
 378
 379         mutex_lock(&ts->input_dev->mutex);
 380
 381         if (input_device_enabled(ts->input_dev))
 382                 retval = imagis_start(ts);
 383
 384         mutex_unlock(&ts->input_dev->mutex);
 385
 386         return retval;
 387 }
 388
 389 static DEFINE_SIMPLE_DEV_PM_OPS(imagis_pm_ops, imagis_suspend, imagis_resume);
 390
 391 static const struct imagis_properties imagis_3032c_data = {
 392         .interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
 393         .touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
 394         .whoami_cmd = IST3038C_REG_CHIPID,
 395         .whoami_val = IST3032C_WHOAMI,
 396         .touch_keys_supported = true,
 397 };
 398
 399 static const struct imagis_properties imagis_3038b_data = {
 400         .interrupt_msg_cmd = IST3038B_REG_STATUS,
 401         .touch_coord_cmd = IST3038B_REG_STATUS,
 402         .whoami_cmd = IST3038B_REG_CHIPID,
 403         .whoami_val = IST3038B_WHOAMI,
 404         .protocol_b = true,
 405 };
 406
 407 static const struct imagis_properties imagis_3038c_data = {
 408         .interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
 409         .touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
 410         .whoami_cmd = IST3038C_REG_CHIPID,
 411         .whoami_val = IST3038C_WHOAMI,
 412 };
 413
 414 #ifdef CONFIG_OF
 415 static const struct of_device_id imagis_of_match[] = {
 416         { .compatible = "imagis,ist3032c", .data = &imagis_3032c_data },
 417         { .compatible = "imagis,ist3038b", .data = &imagis_3038b_data },
 418         { .compatible = "imagis,ist3038c", .data = &imagis_3038c_data },
 419         { },
 420 };
 421 MODULE_DEVICE_TABLE(of, imagis_of_match);
 422 #endif
 423
 424 static struct i2c_driver imagis_ts_driver = {
 425         .driver = {
 426                 .name = "imagis-touchscreen",
 427                 .pm = pm_sleep_ptr(&imagis_pm_ops),
 428                 .of_match_table = of_match_ptr(imagis_of_match),
 429         },
 430         .probe = imagis_probe,
 431 };
 432
 433 module_i2c_driver(imagis_ts_driver);
 434
 435 MODULE_DESCRIPTION("Imagis IST3038C Touchscreen Driver");
 436 MODULE_AUTHOR("Markuss Broks <markuss.broks@gmail.com>");
 437 MODULE_LICENSE("GPL");