Input: add new driver for the Surface 3

This is a basic driver for the Surface 3. I am not so sure it will work
with any firmwares as most values are encoded, but given that I only have
access to my current device with its firmware and I don't have the
datasheet, it should be OK for now.

The Surface Pen is not supported (if it is supposed to be). I'll work on
this when I get one.

Tested-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 75443bb568a6d8068fe3926b3e4404d552848f62..c3880b9e4b61cbbefd2f2ccd5501ca3dbfb37f26 100644 (file)
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -1085,6 +1085,19 @@ config TOUCHSCREEN_SUR40
          To compile this driver as a module, choose M here: the
          module will be called sur40.
 
+config TOUCHSCREEN_SURFACE3_SPI
+       tristate "Ntrig/Microsoft Surface 3 SPI touchscreen"
+       depends on SPI
+       depends on GPIOLIB || COMPILE_TEST
+       help
+         Say Y here if you have the Ntrig/Microsoft SPI touchscreen
+         controller chip as found on the Surface 3 in your system.
+
+         If unsure, say N.
+
+         To compile this driver as a module, choose M here: the
+         module will be called surface3_spi.
+
 config TOUCHSCREEN_SX8654
        tristate "Semtech SX8654 touchscreen"
        depends on I2C

diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 4b518c76e0d75a05bf379c3743e49c526b373139..75af04d7db83252cfe11cd429dbe0b489d1232bd 100644 (file)
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -66,6 +66,7 @@ obj-$(CONFIG_TOUCHSCREEN_ST1232)      += st1232.o
 obj-$(CONFIG_TOUCHSCREEN_STMPE)                += stmpe-ts.o
 obj-$(CONFIG_TOUCHSCREEN_SUN4I)                += sun4i-ts.o
 obj-$(CONFIG_TOUCHSCREEN_SUR40)                += sur40.o
+obj-$(CONFIG_TOUCHSCREEN_SURFACE3_SPI) += surface3_spi.o
 obj-$(CONFIG_TOUCHSCREEN_TI_AM335X_TSC)        += ti_am335x_tsc.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213)   += touchit213.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)   += touchright.o

diff --git a/drivers/input/touchscreen/surface3_spi.c b/drivers/input/touchscreen/surface3_spi.c
new file mode 100644 (file)
index 0000000..e18e742
--- /dev/null
+++ b/drivers/input/touchscreen/surface3_spi.c
@@ -0,0 +1,304 @@
+/*
+ *  Driver for Ntrig/Microsoft Touchscreens over SPI
+ *
+ *  Copyright (c) 2016 Red Hat Inc.
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; version 2 of the License.
+ */
+
+#include <linux/kernel.h>
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/acpi.h>
+
+#include <asm/unaligned.h>
+
+#define SURFACE3_PACKET_SIZE   264
+
+struct surface3_ts_data {
+       struct spi_device *spi;
+       struct gpio_desc *gpiod_rst[2];
+       struct input_dev *input_dev;
+
+       u8 rd_buf[SURFACE3_PACKET_SIZE]         ____cacheline_aligned;
+};
+
+struct surface3_ts_data_finger {
+       u8 status;
+       __le16 tracking_id;
+       __le16 x;
+       __le16 cx;
+       __le16 y;
+       __le16 cy;
+       __le16 width;
+       __le16 height;
+       u32 padding;
+} __packed;
+
+static int surface3_spi_read(struct surface3_ts_data *ts_data)
+{
+       struct spi_device *spi = ts_data->spi;
+
+       memset(ts_data->rd_buf, 0, sizeof(ts_data->rd_buf));
+       return spi_read(spi, ts_data->rd_buf, sizeof(ts_data->rd_buf));
+}
+
+static void surface3_spi_report_touch(struct surface3_ts_data *ts_data,
+                                  struct surface3_ts_data_finger *finger)
+{
+       int st = finger->status & 0x01;
+       int slot;
+
+       slot = input_mt_get_slot_by_key(ts_data->input_dev,
+                               get_unaligned_le16(&finger->tracking_id));
+       if (slot < 0)
+               return;
+
+       input_mt_slot(ts_data->input_dev, slot);
+       input_mt_report_slot_state(ts_data->input_dev, MT_TOOL_FINGER, st);
+       if (st) {
+               input_report_abs(ts_data->input_dev,
+                                ABS_MT_POSITION_X,
+                                get_unaligned_le16(&finger->x));
+               input_report_abs(ts_data->input_dev,
+                                ABS_MT_POSITION_Y,
+                                get_unaligned_le16(&finger->y));
+               input_report_abs(ts_data->input_dev,
+                                ABS_MT_WIDTH_MAJOR,
+                                get_unaligned_le16(&finger->width));
+               input_report_abs(ts_data->input_dev,
+                                ABS_MT_WIDTH_MINOR,
+                                get_unaligned_le16(&finger->height));
+       }
+}
+
+static void surface3_spi_process(struct surface3_ts_data *ts_data)
+{
+       const char header[] = {0xff, 0xff, 0xff, 0xff, 0xa5, 0x5a, 0xe7, 0x7e,
+                              0x01, 0xd2, 0x00, 0x80, 0x01, 0x03, 0x03};
+       u8 *data = ts_data->rd_buf;
+       u16 timestamp;
+       unsigned int i;
+
+       if (memcmp(header, data, sizeof(header)))
+               dev_err(&ts_data->spi->dev,
+                       "%s header error: %*ph, ignoring...\n",
+                       __func__, (int)sizeof(header), data);
+
+       timestamp = get_unaligned_le16(&data[15]);
+
+       for (i = 0; i < 13; i++) {
+               struct surface3_ts_data_finger *finger;
+
+               finger = (struct surface3_ts_data_finger *)&data[17 +
+                               i * sizeof(struct surface3_ts_data_finger)];
+
+               /*
+                * When bit 5 of status is 1, it marks the end of the report:
+                * - touch present: 0xe7
+                * - touch released: 0xe4
+                * - nothing valuable: 0xff
+                */
+               if (finger->status & 0x10)
+                       break;
+
+               surface3_spi_report_touch(ts_data, finger);
+       }
+
+       input_mt_sync_frame(ts_data->input_dev);
+       input_sync(ts_data->input_dev);
+}
+
+static irqreturn_t surface3_spi_irq_handler(int irq, void *dev_id)
+{
+       struct surface3_ts_data *data = dev_id;
+
+       if (surface3_spi_read(data))
+               return IRQ_HANDLED;
+
+       dev_dbg(&data->spi->dev, "%s received -> %*ph\n",
+               __func__, SURFACE3_PACKET_SIZE, data->rd_buf);
+       surface3_spi_process(data);
+
+       return IRQ_HANDLED;
+}
+
+static void surface3_spi_power(struct surface3_ts_data *data, bool on)
+{
+       gpiod_set_value(data->gpiod_rst[0], on);
+       gpiod_set_value(data->gpiod_rst[1], on);
+       /* let the device settle a little */
+       msleep(20);
+}
+
+/**
+ * surface3_spi_get_gpio_config - Get GPIO config from ACPI/DT
+ *
+ * @ts: surface3_spi_ts_data pointer
+ */
+static int surface3_spi_get_gpio_config(struct surface3_ts_data *data)
+{
+       int error;
+       struct device *dev;
+       struct gpio_desc *gpiod;
+       int i;
+
+       dev = &data->spi->dev;
+
+       /* Get the reset lines GPIO pin number */
+       for (i = 0; i < 2; i++) {
+               gpiod = devm_gpiod_get_index(dev, NULL, i, GPIOD_OUT_LOW);
+               if (IS_ERR(gpiod)) {
+                       error = PTR_ERR(gpiod);
+                       if (error != -EPROBE_DEFER)
+                               dev_err(dev,
+                                       "Failed to get power GPIO %d: %d\n",
+                                       i,
+                                       error);
+                       return error;
+               }
+
+               data->gpiod_rst[i] = gpiod;
+       }
+
+       return 0;
+}
+
+static int surface3_spi_create_input(struct surface3_ts_data *data)
+{
+       struct input_dev *input;
+       int error;
+
+       input = devm_input_allocate_device(&data->spi->dev);
+       if (!input)
+               return -ENOMEM;
+
+       data->input_dev = input;
+
+       input_set_abs_params(input, ABS_MT_POSITION_X, 0, 9600, 0, 0);
+       input_abs_set_res(input, ABS_MT_POSITION_X, 40);
+       input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 7200, 0, 0);
+       input_abs_set_res(input, ABS_MT_POSITION_Y, 48);
+       input_set_abs_params(input, ABS_MT_WIDTH_MAJOR, 0, 1024, 0, 0);
+       input_set_abs_params(input, ABS_MT_WIDTH_MINOR, 0, 1024, 0, 0);
+       input_mt_init_slots(input, 10, INPUT_MT_DIRECT);
+
+       input->name = "Surface3 SPI Capacitive TouchScreen";
+       input->phys = "input/ts";
+       input->id.bustype = BUS_SPI;
+       input->id.vendor = 0x045e;      /* Microsoft */
+       input->id.product = 0x0000;
+       input->id.version = 0x0000;
+
+       error = input_register_device(input);
+       if (error) {
+               dev_err(&data->spi->dev,
+                       "Failed to register input device: %d", error);
+               return error;
+       }
+
+       return 0;
+}
+
+static int surface3_spi_probe(struct spi_device *spi)
+{
+       struct surface3_ts_data *data;
+       int error;
+
+       /* Set up SPI*/
+       spi->bits_per_word = 8;
+       spi->mode = SPI_MODE_0;
+       error = spi_setup(spi);
+       if (error)
+               return error;
+
+       data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       data->spi = spi;
+       spi_set_drvdata(spi, data);
+
+       error = surface3_spi_get_gpio_config(data);
+       if (error)
+               return error;
+
+       surface3_spi_power(data, true);
+       surface3_spi_power(data, false);
+       surface3_spi_power(data, true);
+
+       error = surface3_spi_create_input(data);
+       if (error)
+               return error;
+
+       error = devm_request_threaded_irq(&spi->dev, spi->irq,
+                                         NULL, surface3_spi_irq_handler,
+                                         IRQF_ONESHOT,
+                                         "Surface3-irq", data);
+       if (error)
+               return error;
+
+       return 0;
+}
+
+static int __maybe_unused surface3_spi_suspend(struct device *dev)
+{
+       struct spi_device *spi = to_spi_device(dev);
+       struct surface3_ts_data *data = spi_get_drvdata(spi);
+
+       disable_irq(data->spi->irq);
+
+       surface3_spi_power(data, false);
+
+       return 0;
+}
+
+static int __maybe_unused surface3_spi_resume(struct device *dev)
+{
+       struct spi_device *spi = to_spi_device(dev);
+       struct surface3_ts_data *data = spi_get_drvdata(spi);
+
+       surface3_spi_power(data, true);
+
+       enable_irq(data->spi->irq);
+
+       return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(surface3_spi_pm_ops,
+                        surface3_spi_suspend,
+                        surface3_spi_resume);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id surface3_spi_acpi_match[] = {
+       { "MSHW0037", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(acpi, surface3_spi_acpi_match);
+#endif
+
+static struct spi_driver surface3_spi_driver = {
+       .driver = {
+               .name   = "Surface3-spi",
+               .acpi_match_table = ACPI_PTR(surface3_spi_acpi_match),
+               .pm = &surface3_spi_pm_ops,
+       },
+       .probe = surface3_spi_probe,
+};
+
+module_spi_driver(surface3_spi_driver);
+
+MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
+MODULE_DESCRIPTION("Surface 3 SPI touchscreen driver");
+MODULE_LICENSE("GPL v2");