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Commit 4feacbc2 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Dmitry Torokhov
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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: default avatarBastien Nocera <hadess@hadess.net>
Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent b55eb298

drivers/input/touchscreen/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -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

drivers/input/touchscreen/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/input/touchscreen/surface3_spi.c

0 → 100644
+304 −0
Original line number Diff line number Diff line 
/*

 *  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");