input/touchscreen/surface3_spi.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  *  Driver for Ntrig/Microsoft Touchscreens over SPI
0004  *
0005  *  Copyright (c) 2016 Red Hat Inc.
0006  */
0007
0008
0009 #include <linux/kernel.h>
0010
0011 #include <linux/delay.h>
0012 #include <linux/gpio/consumer.h>
0013 #include <linux/input.h>
0014 #include <linux/input/mt.h>
0015 #include <linux/interrupt.h>
0016 #include <linux/module.h>
0017 #include <linux/slab.h>
0018 #include <linux/spi/spi.h>
0019 #include <linux/acpi.h>
0020
0021 #include <asm/unaligned.h>
0022
0023 #define SURFACE3_PACKET_SIZE    264
0024
0025 #define SURFACE3_REPORT_TOUCH   0xd2
0026 #define SURFACE3_REPORT_PEN 0x16
0027
0028 struct surface3_ts_data {
0029     struct spi_device *spi;
0030     struct gpio_desc *gpiod_rst[2];
0031     struct input_dev *input_dev;
0032     struct input_dev *pen_input_dev;
0033     int pen_tool;
0034
0035     u8 rd_buf[SURFACE3_PACKET_SIZE]     ____cacheline_aligned;
0036 };
0037
0038 struct surface3_ts_data_finger {
0039     u8 status;
0040     __le16 tracking_id;
0041     __le16 x;
0042     __le16 cx;
0043     __le16 y;
0044     __le16 cy;
0045     __le16 width;
0046     __le16 height;
0047     u32 padding;
0048 } __packed;
0049
0050 struct surface3_ts_data_pen {
0051     u8 status;
0052     __le16 x;
0053     __le16 y;
0054     __le16 pressure;
0055     u8 padding;
0056 } __packed;
0057
0058 static int surface3_spi_read(struct surface3_ts_data *ts_data)
0059 {
0060     struct spi_device *spi = ts_data->spi;
0061
0062     memset(ts_data->rd_buf, 0, sizeof(ts_data->rd_buf));
0063     return spi_read(spi, ts_data->rd_buf, sizeof(ts_data->rd_buf));
0064 }
0065
0066 static void surface3_spi_report_touch(struct surface3_ts_data *ts_data,
0067                    struct surface3_ts_data_finger *finger)
0068 {
0069     int st = finger->status & 0x01;
0070     int slot;
0071
0072     slot = input_mt_get_slot_by_key(ts_data->input_dev,
0073                 get_unaligned_le16(&finger->tracking_id));
0074     if (slot < 0)
0075         return;
0076
0077     input_mt_slot(ts_data->input_dev, slot);
0078     input_mt_report_slot_state(ts_data->input_dev, MT_TOOL_FINGER, st);
0079     if (st) {
0080         input_report_abs(ts_data->input_dev,
0081                  ABS_MT_POSITION_X,
0082                  get_unaligned_le16(&finger->x));
0083         input_report_abs(ts_data->input_dev,
0084                  ABS_MT_POSITION_Y,
0085                  get_unaligned_le16(&finger->y));
0086         input_report_abs(ts_data->input_dev,
0087                  ABS_MT_WIDTH_MAJOR,
0088                  get_unaligned_le16(&finger->width));
0089         input_report_abs(ts_data->input_dev,
0090                  ABS_MT_WIDTH_MINOR,
0091                  get_unaligned_le16(&finger->height));
0092     }
0093 }
0094
0095 static void surface3_spi_process_touch(struct surface3_ts_data *ts_data, u8 *data)
0096 {
0097     unsigned int i;
0098
0099     for (i = 0; i < 13; i++) {
0100         struct surface3_ts_data_finger *finger;
0101
0102         finger = (struct surface3_ts_data_finger *)&data[17 +
0103                 i * sizeof(struct surface3_ts_data_finger)];
0104
0105         /*
0106          * When bit 5 of status is 1, it marks the end of the report:
0107          * - touch present: 0xe7
0108          * - touch released: 0xe4
0109          * - nothing valuable: 0xff
0110          */
0111         if (finger->status & 0x10)
0112             break;
0113
0114         surface3_spi_report_touch(ts_data, finger);
0115     }
0116
0117     input_mt_sync_frame(ts_data->input_dev);
0118     input_sync(ts_data->input_dev);
0119 }
0120
0121 static void surface3_spi_report_pen(struct surface3_ts_data *ts_data,
0122                     struct surface3_ts_data_pen *pen)
0123 {
0124     struct input_dev *dev = ts_data->pen_input_dev;
0125     int st = pen->status;
0126     int prox = st & 0x01;
0127     int rubber = st & 0x18;
0128     int tool = (prox && rubber) ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
0129
0130     /* fake proximity out to switch tools */
0131     if (ts_data->pen_tool != tool) {
0132         input_report_key(dev, ts_data->pen_tool, 0);
0133         input_sync(dev);
0134         ts_data->pen_tool = tool;
0135     }
0136
0137     input_report_key(dev, BTN_TOUCH, st & 0x12);
0138
0139     input_report_key(dev, ts_data->pen_tool, prox);
0140
0141     if (st) {
0142         input_report_key(dev,
0143                  BTN_STYLUS,
0144                  st & 0x04);
0145
0146         input_report_abs(dev,
0147                  ABS_X,
0148                  get_unaligned_le16(&pen->x));
0149         input_report_abs(dev,
0150                  ABS_Y,
0151                  get_unaligned_le16(&pen->y));
0152         input_report_abs(dev,
0153                  ABS_PRESSURE,
0154                  get_unaligned_le16(&pen->pressure));
0155     }
0156 }
0157
0158 static void surface3_spi_process_pen(struct surface3_ts_data *ts_data, u8 *data)
0159 {
0160     struct surface3_ts_data_pen *pen;
0161
0162     pen = (struct surface3_ts_data_pen *)&data[15];
0163
0164     surface3_spi_report_pen(ts_data, pen);
0165     input_sync(ts_data->pen_input_dev);
0166 }
0167
0168 static void surface3_spi_process(struct surface3_ts_data *ts_data)
0169 {
0170     static const char header[] = {
0171         0xff, 0xff, 0xff, 0xff, 0xa5, 0x5a, 0xe7, 0x7e, 0x01
0172     };
0173     u8 *data = ts_data->rd_buf;
0174
0175     if (memcmp(header, data, sizeof(header)))
0176         dev_err(&ts_data->spi->dev,
0177             "%s header error: %*ph, ignoring...\n",
0178             __func__, (int)sizeof(header), data);
0179
0180     switch (data[9]) {
0181     case SURFACE3_REPORT_TOUCH:
0182         surface3_spi_process_touch(ts_data, data);
0183         break;
0184     case SURFACE3_REPORT_PEN:
0185         surface3_spi_process_pen(ts_data, data);
0186         break;
0187     default:
0188         dev_err(&ts_data->spi->dev,
0189             "%s unknown packet type: %x, ignoring...\n",
0190             __func__, data[9]);
0191         break;
0192     }
0193 }
0194
0195 static irqreturn_t surface3_spi_irq_handler(int irq, void *dev_id)
0196 {
0197     struct surface3_ts_data *data = dev_id;
0198
0199     if (surface3_spi_read(data))
0200         return IRQ_HANDLED;
0201
0202     dev_dbg(&data->spi->dev, "%s received -> %*ph\n",
0203         __func__, SURFACE3_PACKET_SIZE, data->rd_buf);
0204     surface3_spi_process(data);
0205
0206     return IRQ_HANDLED;
0207 }
0208
0209 static void surface3_spi_power(struct surface3_ts_data *data, bool on)
0210 {
0211     gpiod_set_value(data->gpiod_rst[0], on);
0212     gpiod_set_value(data->gpiod_rst[1], on);
0213     /* let the device settle a little */
0214     msleep(20);
0215 }
0216
0217 /**
0218  * surface3_spi_get_gpio_config - Get GPIO config from ACPI/DT
0219  *
0220  * @data: surface3_spi_ts_data pointer
0221  */
0222 static int surface3_spi_get_gpio_config(struct surface3_ts_data *data)
0223 {
0224     int error;
0225     struct device *dev;
0226     struct gpio_desc *gpiod;
0227     int i;
0228
0229     dev = &data->spi->dev;
0230
0231     /* Get the reset lines GPIO pin number */
0232     for (i = 0; i < 2; i++) {
0233         gpiod = devm_gpiod_get_index(dev, NULL, i, GPIOD_OUT_LOW);
0234         if (IS_ERR(gpiod)) {
0235             error = PTR_ERR(gpiod);
0236             if (error != -EPROBE_DEFER)
0237                 dev_err(dev,
0238                     "Failed to get power GPIO %d: %d\n",
0239                     i,
0240                     error);
0241             return error;
0242         }
0243
0244         data->gpiod_rst[i] = gpiod;
0245     }
0246
0247     return 0;
0248 }
0249
0250 static int surface3_spi_create_touch_input(struct surface3_ts_data *data)
0251 {
0252     struct input_dev *input;
0253     int error;
0254
0255     input = devm_input_allocate_device(&data->spi->dev);
0256     if (!input)
0257         return -ENOMEM;
0258
0259     data->input_dev = input;
0260
0261     input_set_abs_params(input, ABS_MT_POSITION_X, 0, 9600, 0, 0);
0262     input_abs_set_res(input, ABS_MT_POSITION_X, 40);
0263     input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 7200, 0, 0);
0264     input_abs_set_res(input, ABS_MT_POSITION_Y, 48);
0265     input_set_abs_params(input, ABS_MT_WIDTH_MAJOR, 0, 1024, 0, 0);
0266     input_set_abs_params(input, ABS_MT_WIDTH_MINOR, 0, 1024, 0, 0);
0267     input_mt_init_slots(input, 10, INPUT_MT_DIRECT);
0268
0269     input->name = "Surface3 SPI Capacitive TouchScreen";
0270     input->phys = "input/ts";
0271     input->id.bustype = BUS_SPI;
0272     input->id.vendor = 0x045e;  /* Microsoft */
0273     input->id.product = 0x0001;
0274     input->id.version = 0x0000;
0275
0276     error = input_register_device(input);
0277     if (error) {
0278         dev_err(&data->spi->dev,
0279             "Failed to register input device: %d", error);
0280         return error;
0281     }
0282
0283     return 0;
0284 }
0285
0286 static int surface3_spi_create_pen_input(struct surface3_ts_data *data)
0287 {
0288     struct input_dev *input;
0289     int error;
0290
0291     input = devm_input_allocate_device(&data->spi->dev);
0292     if (!input)
0293         return -ENOMEM;
0294
0295     data->pen_input_dev = input;
0296     data->pen_tool = BTN_TOOL_PEN;
0297
0298     __set_bit(INPUT_PROP_DIRECT, input->propbit);
0299     __set_bit(INPUT_PROP_POINTER, input->propbit);
0300     input_set_abs_params(input, ABS_X, 0, 9600, 0, 0);
0301     input_abs_set_res(input, ABS_X, 40);
0302     input_set_abs_params(input, ABS_Y, 0, 7200, 0, 0);
0303     input_abs_set_res(input, ABS_Y, 48);
0304     input_set_abs_params(input, ABS_PRESSURE, 0, 1024, 0, 0);
0305     input_set_capability(input, EV_KEY, BTN_TOUCH);
0306     input_set_capability(input, EV_KEY, BTN_STYLUS);
0307     input_set_capability(input, EV_KEY, BTN_TOOL_PEN);
0308     input_set_capability(input, EV_KEY, BTN_TOOL_RUBBER);
0309
0310     input->name = "Surface3 SPI Pen Input";
0311     input->phys = "input/ts";
0312     input->id.bustype = BUS_SPI;
0313     input->id.vendor = 0x045e;     /* Microsoft */
0314     input->id.product = 0x0002;
0315     input->id.version = 0x0000;
0316
0317     error = input_register_device(input);
0318     if (error) {
0319         dev_err(&data->spi->dev,
0320             "Failed to register input device: %d", error);
0321         return error;
0322     }
0323
0324     return 0;
0325 }
0326
0327 static int surface3_spi_probe(struct spi_device *spi)
0328 {
0329     struct surface3_ts_data *data;
0330     int error;
0331
0332     /* Set up SPI*/
0333     spi->bits_per_word = 8;
0334     spi->mode = SPI_MODE_0;
0335     error = spi_setup(spi);
0336     if (error)
0337         return error;
0338
0339     data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
0340     if (!data)
0341         return -ENOMEM;
0342
0343     data->spi = spi;
0344     spi_set_drvdata(spi, data);
0345
0346     error = surface3_spi_get_gpio_config(data);
0347     if (error)
0348         return error;
0349
0350     surface3_spi_power(data, true);
0351     surface3_spi_power(data, false);
0352     surface3_spi_power(data, true);
0353
0354     error = surface3_spi_create_touch_input(data);
0355     if (error)
0356         return error;
0357
0358     error = surface3_spi_create_pen_input(data);
0359     if (error)
0360         return error;
0361
0362     error = devm_request_threaded_irq(&spi->dev, spi->irq,
0363                       NULL, surface3_spi_irq_handler,
0364                       IRQF_ONESHOT,
0365                       "Surface3-irq", data);
0366     if (error)
0367         return error;
0368
0369     return 0;
0370 }
0371
0372 static int __maybe_unused surface3_spi_suspend(struct device *dev)
0373 {
0374     struct spi_device *spi = to_spi_device(dev);
0375     struct surface3_ts_data *data = spi_get_drvdata(spi);
0376
0377     disable_irq(data->spi->irq);
0378
0379     surface3_spi_power(data, false);
0380
0381     return 0;
0382 }
0383
0384 static int __maybe_unused surface3_spi_resume(struct device *dev)
0385 {
0386     struct spi_device *spi = to_spi_device(dev);
0387     struct surface3_ts_data *data = spi_get_drvdata(spi);
0388
0389     surface3_spi_power(data, true);
0390
0391     enable_irq(data->spi->irq);
0392
0393     return 0;
0394 }
0395
0396 static SIMPLE_DEV_PM_OPS(surface3_spi_pm_ops,
0397              surface3_spi_suspend,
0398              surface3_spi_resume);
0399
0400 #ifdef CONFIG_ACPI
0401 static const struct acpi_device_id surface3_spi_acpi_match[] = {
0402     { "MSHW0037", 0 },
0403     { }
0404 };
0405 MODULE_DEVICE_TABLE(acpi, surface3_spi_acpi_match);
0406 #endif
0407
0408 static struct spi_driver surface3_spi_driver = {
0409     .driver = {
0410         .name   = "Surface3-spi",
0411         .acpi_match_table = ACPI_PTR(surface3_spi_acpi_match),
0412         .pm = &surface3_spi_pm_ops,
0413     },
0414     .probe = surface3_spi_probe,
0415 };
0416
0417 module_spi_driver(surface3_spi_driver);
0418
0419 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
0420 MODULE_DESCRIPTION("Surface 3 SPI touchscreen driver");
0421 MODULE_LICENSE("GPL v2");