drivers/input/touchscreen/surface3_spi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Driver for Ntrig/Microsoft Touchscreens over SPI
   4  *
   5  *  Copyright (c) 2016 Red Hat Inc.
   6  */
   7
   8
   9 #include <linux/kernel.h>
  10
  11 #include <linux/delay.h>
  12 #include <linux/gpio/consumer.h>
  13 #include <linux/input.h>
  14 #include <linux/input/mt.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/spi/spi.h>
  19 #include <linux/acpi.h>
  20
  21 #include <asm/unaligned.h>
  22
  23 #define SURFACE3_PACKET_SIZE    264
  24
  25 #define SURFACE3_REPORT_TOUCH   0xd2
  26 #define SURFACE3_REPORT_PEN     0x16
  27
  28 struct surface3_ts_data {
  29         struct spi_device *spi;
  30         struct gpio_desc *gpiod_rst[2];
  31         struct input_dev *input_dev;
  32         struct input_dev *pen_input_dev;
  33         int pen_tool;
  34
  35         u8 rd_buf[SURFACE3_PACKET_SIZE]         ____cacheline_aligned;
  36 };
  37
  38 struct surface3_ts_data_finger {
  39         u8 status;
  40         __le16 tracking_id;
  41         __le16 x;
  42         __le16 cx;
  43         __le16 y;
  44         __le16 cy;
  45         __le16 width;
  46         __le16 height;
  47         u32 padding;
  48 } __packed;
  49
  50 struct surface3_ts_data_pen {
  51         u8 status;
  52         __le16 x;
  53         __le16 y;
  54         __le16 pressure;
  55         u8 padding;
  56 } __packed;
  57
  58 static int surface3_spi_read(struct surface3_ts_data *ts_data)
  59 {
  60         struct spi_device *spi = ts_data->spi;
  61
  62         memset(ts_data->rd_buf, 0, sizeof(ts_data->rd_buf));
  63         return spi_read(spi, ts_data->rd_buf, sizeof(ts_data->rd_buf));
  64 }
  65
  66 static void surface3_spi_report_touch(struct surface3_ts_data *ts_data,
  67                                    struct surface3_ts_data_finger *finger)
  68 {
  69         int st = finger->status & 0x01;
  70         int slot;
  71
  72         slot = input_mt_get_slot_by_key(ts_data->input_dev,
  73                                 get_unaligned_le16(&finger->tracking_id));
  74         if (slot < 0)
  75                 return;
  76
  77         input_mt_slot(ts_data->input_dev, slot);
  78         input_mt_report_slot_state(ts_data->input_dev, MT_TOOL_FINGER, st);
  79         if (st) {
  80                 input_report_abs(ts_data->input_dev,
  81                                  ABS_MT_POSITION_X,
  82                                  get_unaligned_le16(&finger->x));
  83                 input_report_abs(ts_data->input_dev,
  84                                  ABS_MT_POSITION_Y,
  85                                  get_unaligned_le16(&finger->y));
  86                 input_report_abs(ts_data->input_dev,
  87                                  ABS_MT_WIDTH_MAJOR,
  88                                  get_unaligned_le16(&finger->width));
  89                 input_report_abs(ts_data->input_dev,
  90                                  ABS_MT_WIDTH_MINOR,
  91                                  get_unaligned_le16(&finger->height));
  92         }
  93 }
  94
  95 static void surface3_spi_process_touch(struct surface3_ts_data *ts_data, u8 *data)
  96 {
  97         u16 timestamp;
  98         unsigned int i;
  99         timestamp = get_unaligned_le16(&data[15]);
 100
 101         for (i = 0; i < 13; i++) {
 102                 struct surface3_ts_data_finger *finger;
 103
 104                 finger = (struct surface3_ts_data_finger *)&data[17 +
 105                                 i * sizeof(struct surface3_ts_data_finger)];
 106
 107                 /*
 108                  * When bit 5 of status is 1, it marks the end of the report:
 109                  * - touch present: 0xe7
 110                  * - touch released: 0xe4
 111                  * - nothing valuable: 0xff
 112                  */
 113                 if (finger->status & 0x10)
 114                         break;
 115
 116                 surface3_spi_report_touch(ts_data, finger);
 117         }
 118
 119         input_mt_sync_frame(ts_data->input_dev);
 120         input_sync(ts_data->input_dev);
 121 }
 122
 123 static void surface3_spi_report_pen(struct surface3_ts_data *ts_data,
 124                                     struct surface3_ts_data_pen *pen)
 125 {
 126         struct input_dev *dev = ts_data->pen_input_dev;
 127         int st = pen->status;
 128         int prox = st & 0x01;
 129         int rubber = st & 0x18;
 130         int tool = (prox && rubber) ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
 131
 132         /* fake proximity out to switch tools */
 133         if (ts_data->pen_tool != tool) {
 134                 input_report_key(dev, ts_data->pen_tool, 0);
 135                 input_sync(dev);
 136                 ts_data->pen_tool = tool;
 137         }
 138
 139         input_report_key(dev, BTN_TOUCH, st & 0x12);
 140
 141         input_report_key(dev, ts_data->pen_tool, prox);
 142
 143         if (st) {
 144                 input_report_key(dev,
 145                                  BTN_STYLUS,
 146                                  st & 0x04);
 147
 148                 input_report_abs(dev,
 149                                  ABS_X,
 150                                  get_unaligned_le16(&pen->x));
 151                 input_report_abs(dev,
 152                                  ABS_Y,
 153                                  get_unaligned_le16(&pen->y));
 154                 input_report_abs(dev,
 155                                  ABS_PRESSURE,
 156                                  get_unaligned_le16(&pen->pressure));
 157         }
 158 }
 159
 160 static void surface3_spi_process_pen(struct surface3_ts_data *ts_data, u8 *data)
 161 {
 162         struct surface3_ts_data_pen *pen;
 163
 164         pen = (struct surface3_ts_data_pen *)&data[15];
 165
 166         surface3_spi_report_pen(ts_data, pen);
 167         input_sync(ts_data->pen_input_dev);
 168 }
 169
 170 static void surface3_spi_process(struct surface3_ts_data *ts_data)
 171 {
 172         static const char header[] = {
 173                 0xff, 0xff, 0xff, 0xff, 0xa5, 0x5a, 0xe7, 0x7e, 0x01
 174         };
 175         u8 *data = ts_data->rd_buf;
 176
 177         if (memcmp(header, data, sizeof(header)))
 178                 dev_err(&ts_data->spi->dev,
 179                         "%s header error: %*ph, ignoring...\n",
 180                         __func__, (int)sizeof(header), data);
 181
 182         switch (data[9]) {
 183         case SURFACE3_REPORT_TOUCH:
 184                 surface3_spi_process_touch(ts_data, data);
 185                 break;
 186         case SURFACE3_REPORT_PEN:
 187                 surface3_spi_process_pen(ts_data, data);
 188                 break;
 189         default:
 190                 dev_err(&ts_data->spi->dev,
 191                         "%s unknown packet type: %x, ignoring...\n",
 192                         __func__, data[9]);
 193                 break;
 194         }
 195 }
 196
 197 static irqreturn_t surface3_spi_irq_handler(int irq, void *dev_id)
 198 {
 199         struct surface3_ts_data *data = dev_id;
 200
 201         if (surface3_spi_read(data))
 202                 return IRQ_HANDLED;
 203
 204         dev_dbg(&data->spi->dev, "%s received -> %*ph\n",
 205                 __func__, SURFACE3_PACKET_SIZE, data->rd_buf);
 206         surface3_spi_process(data);
 207
 208         return IRQ_HANDLED;
 209 }
 210
 211 static void surface3_spi_power(struct surface3_ts_data *data, bool on)
 212 {
 213         gpiod_set_value(data->gpiod_rst[0], on);
 214         gpiod_set_value(data->gpiod_rst[1], on);
 215         /* let the device settle a little */
 216         msleep(20);
 217 }
 218
 219 /**
 220  * surface3_spi_get_gpio_config - Get GPIO config from ACPI/DT
 221  *
 222  * @ts: surface3_spi_ts_data pointer
 223  */
 224 static int surface3_spi_get_gpio_config(struct surface3_ts_data *data)
 225 {
 226         int error;
 227         struct device *dev;
 228         struct gpio_desc *gpiod;
 229         int i;
 230
 231         dev = &data->spi->dev;
 232
 233         /* Get the reset lines GPIO pin number */
 234         for (i = 0; i < 2; i++) {
 235                 gpiod = devm_gpiod_get_index(dev, NULL, i, GPIOD_OUT_LOW);
 236                 if (IS_ERR(gpiod)) {
 237                         error = PTR_ERR(gpiod);
 238                         if (error != -EPROBE_DEFER)
 239                                 dev_err(dev,
 240                                         "Failed to get power GPIO %d: %d\n",
 241                                         i,
 242                                         error);
 243                         return error;
 244                 }
 245
 246                 data->gpiod_rst[i] = gpiod;
 247         }
 248
 249         return 0;
 250 }
 251
 252 static int surface3_spi_create_touch_input(struct surface3_ts_data *data)
 253 {
 254         struct input_dev *input;
 255         int error;
 256
 257         input = devm_input_allocate_device(&data->spi->dev);
 258         if (!input)
 259                 return -ENOMEM;
 260
 261         data->input_dev = input;
 262
 263         input_set_abs_params(input, ABS_MT_POSITION_X, 0, 9600, 0, 0);
 264         input_abs_set_res(input, ABS_MT_POSITION_X, 40);
 265         input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 7200, 0, 0);
 266         input_abs_set_res(input, ABS_MT_POSITION_Y, 48);
 267         input_set_abs_params(input, ABS_MT_WIDTH_MAJOR, 0, 1024, 0, 0);
 268         input_set_abs_params(input, ABS_MT_WIDTH_MINOR, 0, 1024, 0, 0);
 269         input_mt_init_slots(input, 10, INPUT_MT_DIRECT);
 270
 271         input->name = "Surface3 SPI Capacitive TouchScreen";
 272         input->phys = "input/ts";
 273         input->id.bustype = BUS_SPI;
 274         input->id.vendor = 0x045e;      /* Microsoft */
 275         input->id.product = 0x0001;
 276         input->id.version = 0x0000;
 277
 278         error = input_register_device(input);
 279         if (error) {
 280                 dev_err(&data->spi->dev,
 281                         "Failed to register input device: %d", error);
 282                 return error;
 283         }
 284
 285         return 0;
 286 }
 287
 288 static int surface3_spi_create_pen_input(struct surface3_ts_data *data)
 289 {
 290         struct input_dev *input;
 291         int error;
 292
 293         input = devm_input_allocate_device(&data->spi->dev);
 294         if (!input)
 295                 return -ENOMEM;
 296
 297         data->pen_input_dev = input;
 298         data->pen_tool = BTN_TOOL_PEN;
 299
 300         __set_bit(INPUT_PROP_DIRECT, input->propbit);
 301         __set_bit(INPUT_PROP_POINTER, input->propbit);
 302         input_set_abs_params(input, ABS_X, 0, 9600, 0, 0);
 303         input_abs_set_res(input, ABS_X, 40);
 304         input_set_abs_params(input, ABS_Y, 0, 7200, 0, 0);
 305         input_abs_set_res(input, ABS_Y, 48);
 306         input_set_abs_params(input, ABS_PRESSURE, 0, 1024, 0, 0);
 307         input_set_capability(input, EV_KEY, BTN_TOUCH);
 308         input_set_capability(input, EV_KEY, BTN_STYLUS);
 309         input_set_capability(input, EV_KEY, BTN_TOOL_PEN);
 310         input_set_capability(input, EV_KEY, BTN_TOOL_RUBBER);
 311
 312         input->name = "Surface3 SPI Pen Input";
 313         input->phys = "input/ts";
 314         input->id.bustype = BUS_SPI;
 315         input->id.vendor = 0x045e;     /* Microsoft */
 316         input->id.product = 0x0002;
 317         input->id.version = 0x0000;
 318
 319         error = input_register_device(input);
 320         if (error) {
 321                 dev_err(&data->spi->dev,
 322                         "Failed to register input device: %d", error);
 323                 return error;
 324         }
 325
 326         return 0;
 327 }
 328
 329 static int surface3_spi_probe(struct spi_device *spi)
 330 {
 331         struct surface3_ts_data *data;
 332         int error;
 333
 334         /* Set up SPI*/
 335         spi->bits_per_word = 8;
 336         spi->mode = SPI_MODE_0;
 337         error = spi_setup(spi);
 338         if (error)
 339                 return error;
 340
 341         data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
 342         if (!data)
 343                 return -ENOMEM;
 344
 345         data->spi = spi;
 346         spi_set_drvdata(spi, data);
 347
 348         error = surface3_spi_get_gpio_config(data);
 349         if (error)
 350                 return error;
 351
 352         surface3_spi_power(data, true);
 353         surface3_spi_power(data, false);
 354         surface3_spi_power(data, true);
 355
 356         error = surface3_spi_create_touch_input(data);
 357         if (error)
 358                 return error;
 359
 360         error = surface3_spi_create_pen_input(data);
 361         if (error)
 362                 return error;
 363
 364         error = devm_request_threaded_irq(&spi->dev, spi->irq,
 365                                           NULL, surface3_spi_irq_handler,
 366                                           IRQF_ONESHOT,
 367                                           "Surface3-irq", data);
 368         if (error)
 369                 return error;
 370
 371         return 0;
 372 }
 373
 374 static int __maybe_unused surface3_spi_suspend(struct device *dev)
 375 {
 376         struct spi_device *spi = to_spi_device(dev);
 377         struct surface3_ts_data *data = spi_get_drvdata(spi);
 378
 379         disable_irq(data->spi->irq);
 380
 381         surface3_spi_power(data, false);
 382
 383         return 0;
 384 }
 385
 386 static int __maybe_unused surface3_spi_resume(struct device *dev)
 387 {
 388         struct spi_device *spi = to_spi_device(dev);
 389         struct surface3_ts_data *data = spi_get_drvdata(spi);
 390
 391         surface3_spi_power(data, true);
 392
 393         enable_irq(data->spi->irq);
 394
 395         return 0;
 396 }
 397
 398 static SIMPLE_DEV_PM_OPS(surface3_spi_pm_ops,
 399                          surface3_spi_suspend,
 400                          surface3_spi_resume);
 401
 402 #ifdef CONFIG_ACPI
 403 static const struct acpi_device_id surface3_spi_acpi_match[] = {
 404         { "MSHW0037", 0 },
 405         { }
 406 };
 407 MODULE_DEVICE_TABLE(acpi, surface3_spi_acpi_match);
 408 #endif
 409
 410 static struct spi_driver surface3_spi_driver = {
 411         .driver = {
 412                 .name   = "Surface3-spi",
 413                 .acpi_match_table = ACPI_PTR(surface3_spi_acpi_match),
 414                 .pm = &surface3_spi_pm_ops,
 415         },
 416         .probe = surface3_spi_probe,
 417 };
 418
 419 module_spi_driver(surface3_spi_driver);
 420
 421 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
 422 MODULE_DESCRIPTION("Surface 3 SPI touchscreen driver");
 423 MODULE_LICENSE("GPL v2");