Release 4.11 drivers/input/touchscreen/sur40.c

/*
 * Surface2.0/SUR40/PixelSense input driver
 *
 * Copyright (c) 2014 by Florian 'floe' Echtler <floe@butterbrot.org>
 *
 * Derived from the USB Skeleton driver 1.1,
 * Copyright (c) 2003 Greg Kroah-Hartman (greg@kroah.com)
 *
 * and from the Apple USB BCM5974 multitouch driver,
 * Copyright (c) 2008 Henrik Rydberg (rydberg@euromail.se)
 *
 * and from the generic hid-multitouch driver,
 * Copyright (c) 2010-2012 Stephane Chatty <chatty@enac.fr>
 *
 * and from the v4l2-pci-skeleton driver,
 * Copyright (c) Copyright 2014 Cisco Systems, 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; either version 2 of
 * the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/completion.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/printk.h>
#include <linux/input-polldev.h>
#include <linux/input/mt.h>
#include <linux/usb/input.h>
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-ioctl.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-dma-sg.h>

/* read 512 bytes from endpoint 0x86 -> get header + blobs */

struct sur40_header {

	
__le16 type;       /* always 0x0001 */
	
__le16 count;      /* count of blobs (if 0: continue prev. packet) */

	
__le32 packet_id;  /* unique ID for all packets in one frame */

	
__le32 timestamp;  /* milliseconds (inc. by 16 or 17 each frame) */
	
__le32 unknown;    /* "epoch?" always 02/03 00 00 00 */

} 
__packed;


struct sur40_blob {

	
__le16 blob_id;

	
u8 action;         /* 0x02 = enter/exit, 0x03 = update (?) */
	
u8 unknown;        /* always 0x01 or 0x02 (no idea what this is?) */

	
__le16 bb_pos_x;   /* upper left corner of bounding box */
	
__le16 bb_pos_y;

	
__le16 bb_size_x;  /* size of bounding box */
	
__le16 bb_size_y;

	
__le16 pos_x;      /* finger tip position */
	
__le16 pos_y;

	
__le16 ctr_x;      /* centroid position */
	
__le16 ctr_y;

	
__le16 axis_x;     /* somehow related to major/minor axis, mostly: */
	
__le16 axis_y;     /* axis_x == bb_size_y && axis_y == bb_size_x */

	
__le32 angle;      /* orientation in radians relative to x axis -
                              actually an IEEE754 float, don't use in kernel */

	
__le32 area;       /* size in pixels/pressure (?) */

	
u8 padding[32];

} 
__packed;

/* combined header/blob data */

struct sur40_data {
	
struct sur40_header header;
	
struct sur40_blob   blobs[];
} 
__packed;

/* read 512 bytes from endpoint 0x82 -> get header below
 * continue reading 16k blocks until header.size bytes read */

struct sur40_image_header {
	
__le32 magic;     /* "SUBF" */
	
__le32 packet_id;
	
__le32 size;      /* always 0x0007e900 = 960x540 */
	
__le32 timestamp; /* milliseconds (increases by 16 or 17 each frame) */
	
__le32 unknown;   /* "epoch?" always 02/03 00 00 00 */
} 
__packed;

/* version information */

#define DRIVER_SHORT   "sur40"

#define DRIVER_LONG    "Samsung SUR40"

#define DRIVER_AUTHOR  "Florian 'floe' Echtler <floe@butterbrot.org>"

#define DRIVER_DESC    "Surface2.0/SUR40/PixelSense input driver"

/* vendor and device IDs */

#define ID_MICROSOFT 0x045e

#define ID_SUR40     0x0775

/* sensor resolution */

#define SENSOR_RES_X 1920

#define SENSOR_RES_Y 1080

/* touch data endpoint */

#define TOUCH_ENDPOINT 0x86

/* video data endpoint */

#define VIDEO_ENDPOINT 0x82

/* video header fields */

#define VIDEO_HEADER_MAGIC 0x46425553

#define VIDEO_PACKET_SIZE  16384

/* polling interval (ms) */

#define POLL_INTERVAL 1

/* maximum number of contacts FIXME: this is a guess? */

#define MAX_CONTACTS 64

/* control commands */

#define SUR40_GET_VERSION 0xb0 
/* 12 bytes string    */

#define SUR40_UNKNOWN1    0xb3 
/*  5 bytes           */

#define SUR40_UNKNOWN2    0xc1 
/* 24 bytes           */


#define SUR40_GET_STATE   0xc5 
/*  4 bytes state (?) */

#define SUR40_GET_SENSORS 0xb1 
/*  8 bytes sensors   */


static const struct v4l2_pix_format sur40_pix_format[] = {
	{
		.pixelformat = V4L2_TCH_FMT_TU08,
		.width  = SENSOR_RES_X / 2,
		.height = SENSOR_RES_Y / 2,
		.field = V4L2_FIELD_NONE,
		.colorspace = V4L2_COLORSPACE_SRGB,
		.bytesperline = SENSOR_RES_X / 2,
		.sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
        },
	{
		.pixelformat = V4L2_PIX_FMT_GREY,
		.width  = SENSOR_RES_X / 2,
		.height = SENSOR_RES_Y / 2,
		.field = V4L2_FIELD_NONE,
		.colorspace = V4L2_COLORSPACE_SRGB,
		.bytesperline = SENSOR_RES_X / 2,
		.sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
        }
};

/* master device state */

struct sur40_state {

	
struct usb_device *usbdev;
	
struct device *dev;
	
struct input_polled_dev *input;

	
struct v4l2_device v4l2;
	
struct video_device vdev;
	
struct mutex lock;
	
struct v4l2_pix_format pix_fmt;

	
struct vb2_queue queue;
	
struct list_head buf_list;
	
spinlock_t qlock;
	
int sequence;

	
struct sur40_data *bulk_in_buffer;
	
size_t bulk_in_size;
	
u8 bulk_in_epaddr;

	
char phys[64];
};


struct sur40_buffer {
	
struct vb2_v4l2_buffer vb;
	
struct list_head list;
};

/* forward declarations */

static const struct video_device sur40_video_device;

static const struct vb2_queue sur40_queue;
static void sur40_process_video(struct sur40_state *sur40);

/*
 * Note: an earlier, non-public version of this driver used USB_RECIP_ENDPOINT
 * here by mistake which is very likely to have corrupted the firmware EEPROM
 * on two separate SUR40 devices. Thanks to Alan Stern who spotted this bug.
 * Should you ever run into a similar problem, the background story to this
 * incident and instructions on how to fix the corrupted EEPROM are available
 * at https://floe.butterbrot.org/matrix/hacking/surface/brick.html
*/

/* command wrapper */


static int sur40_command(struct sur40_state *dev,
			 u8 command, u16 index, void *buffer, u16 size)
{
	return usb_control_msg(dev->usbdev, usb_rcvctrlpipe(dev->usbdev, 0),
			       command,
			       USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
			       0x00, index, buffer, size, 1000);
}

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/* Initialization routine, called from sur40_open */


static int sur40_init(struct sur40_state *dev)
{
	int result;
	u8 *buffer;

	buffer = kmalloc(24, GFP_KERNEL);
	if (!buffer) {
		result = -ENOMEM;
		goto error;
	}

	/* stupidly replay the original MS driver init sequence */
	result = sur40_command(dev, SUR40_GET_VERSION, 0x00, buffer, 12);
	if (result < 0)
		goto error;

	result = sur40_command(dev, SUR40_GET_VERSION, 0x01, buffer, 12);
	if (result < 0)
		goto error;

	result = sur40_command(dev, SUR40_GET_VERSION, 0x02, buffer, 12);
	if (result < 0)
		goto error;

	result = sur40_command(dev, SUR40_UNKNOWN2,    0x00, buffer, 24);
	if (result < 0)
		goto error;

	result = sur40_command(dev, SUR40_UNKNOWN1,    0x00, buffer,  5);
	if (result < 0)
		goto error;

	result = sur40_command(dev, SUR40_GET_VERSION, 0x03, buffer, 12);

	/*
         * Discard the result buffer - no known data inside except
         * some version strings, maybe extract these sometime...
         */
error:
	kfree(buffer);
	return result;
}

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/*
 * Callback routines from input_polled_dev
 */

/* Enable the device, polling will now start. */


static void sur40_open(struct input_polled_dev *polldev)
{
	struct sur40_state *sur40 = polldev->private;

	dev_dbg(sur40->dev, "open\n");
	sur40_init(sur40);
}

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/* Disable device, polling has stopped. */


static void sur40_close(struct input_polled_dev *polldev)
{
	struct sur40_state *sur40 = polldev->private;

	dev_dbg(sur40->dev, "close\n");
	/*
         * There is no known way to stop the device, so we simply
         * stop polling.
         */
}

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/*
 * This function is called when a whole contact has been processed,
 * so that it can assign it to a slot and store the data there.
 */


static void sur40_report_blob(struct sur40_blob *blob, struct input_dev *input)
{
	int wide, major, minor;

	int bb_size_x = le16_to_cpu(blob->bb_size_x);
	int bb_size_y = le16_to_cpu(blob->bb_size_y);

	int pos_x = le16_to_cpu(blob->pos_x);
	int pos_y = le16_to_cpu(blob->pos_y);

	int ctr_x = le16_to_cpu(blob->ctr_x);
	int ctr_y = le16_to_cpu(blob->ctr_y);

	int slotnum = input_mt_get_slot_by_key(input, blob->blob_id);
	if (slotnum < 0 || slotnum >= MAX_CONTACTS)
		return;

	input_mt_slot(input, slotnum);
	input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
	wide = (bb_size_x > bb_size_y);
	major = max(bb_size_x, bb_size_y);
	minor = min(bb_size_x, bb_size_y);

	input_report_abs(input, ABS_MT_POSITION_X, pos_x);
	input_report_abs(input, ABS_MT_POSITION_Y, pos_y);
	input_report_abs(input, ABS_MT_TOOL_X, ctr_x);
	input_report_abs(input, ABS_MT_TOOL_Y, ctr_y);

	/* TODO: use a better orientation measure */
	input_report_abs(input, ABS_MT_ORIENTATION, wide);
	input_report_abs(input, ABS_MT_TOUCH_MAJOR, major);
	input_report_abs(input, ABS_MT_TOUCH_MINOR, minor);
}

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/* core function: poll for new input data */


static void sur40_poll(struct input_polled_dev *polldev)
{
	struct sur40_state *sur40 = polldev->private;
	struct input_dev *input = polldev->input;
	int result, bulk_read, need_blobs, packet_blobs, i;
	u32 uninitialized_var(packet_id);

	struct sur40_header *header = &sur40->bulk_in_buffer->header;
	struct sur40_blob *inblob = &sur40->bulk_in_buffer->blobs[0];

	dev_dbg(sur40->dev, "poll\n");

	need_blobs = -1;

	do {

		/* perform a blocking bulk read to get data from the device */
		result = usb_bulk_msg(sur40->usbdev,
			usb_rcvbulkpipe(sur40->usbdev, sur40->bulk_in_epaddr),
			sur40->bulk_in_buffer, sur40->bulk_in_size,
			&bulk_read, 1000);

		dev_dbg(sur40->dev, "received %d bytes\n", bulk_read);

		if (result < 0) {
			dev_err(sur40->dev, "error in usb_bulk_read\n");
			return;
		}

		result = bulk_read - sizeof(struct sur40_header);

		if (result % sizeof(struct sur40_blob) != 0) {
			dev_err(sur40->dev, "transfer size mismatch\n");
			return;
		}

		/* first packet? */
		if (need_blobs == -1) {
			need_blobs = le16_to_cpu(header->count);
			dev_dbg(sur40->dev, "need %d blobs\n", need_blobs);
			packet_id = le32_to_cpu(header->packet_id);
		}

		/*
                 * Sanity check. when video data is also being retrieved, the
                 * packet ID will usually increase in the middle of a series
                 * instead of at the end.
                 */
		if (packet_id != header->packet_id)
			dev_dbg(sur40->dev, "packet ID mismatch\n");

		packet_blobs = result / sizeof(struct sur40_blob);
		dev_dbg(sur40->dev, "received %d blobs\n", packet_blobs);

		/* packets always contain at least 4 blobs, even if empty */
		if (packet_blobs > need_blobs)
			packet_blobs = need_blobs;

		for (i = 0; i < packet_blobs; i++) {
			need_blobs--;
			dev_dbg(sur40->dev, "processing blob\n");
			sur40_report_blob(&(inblob[i]), input);
		}

	} while (need_blobs > 0);

	input_mt_sync_frame(input);
	input_sync(input);

	sur40_process_video(sur40);
}

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/* deal with video data */


static void sur40_process_video(struct sur40_state *sur40)
{

	struct sur40_image_header *img = (void *)(sur40->bulk_in_buffer);
	struct sur40_buffer *new_buf;
	struct usb_sg_request sgr;
	struct sg_table *sgt;
	int result, bulk_read;

	if (!vb2_start_streaming_called(&sur40->queue))
		return;

	/* get a new buffer from the list */
	spin_lock(&sur40->qlock);
	if (list_empty(&sur40->buf_list)) {
		dev_dbg(sur40->dev, "buffer queue empty\n");
		spin_unlock(&sur40->qlock);
		return;
	}
	new_buf = list_entry(sur40->buf_list.next, struct sur40_buffer, list);
	list_del(&new_buf->list);
	spin_unlock(&sur40->qlock);

	dev_dbg(sur40->dev, "buffer acquired\n");

	/* retrieve data via bulk read */
	result = usb_bulk_msg(sur40->usbdev,
			usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT),
			sur40->bulk_in_buffer, sur40->bulk_in_size,
			&bulk_read, 1000);

	if (result < 0) {
		dev_err(sur40->dev, "error in usb_bulk_read\n");
		goto err_poll;
	}

	if (bulk_read != sizeof(struct sur40_image_header)) {
		dev_err(sur40->dev, "received %d bytes (%zd expected)\n",
			bulk_read, sizeof(struct sur40_image_header));
		goto err_poll;
	}

	if (le32_to_cpu(img->magic) != VIDEO_HEADER_MAGIC) {
		dev_err(sur40->dev, "image magic mismatch\n");
		goto err_poll;
	}

	if (le32_to_cpu(img->size) != sur40->pix_fmt.sizeimage) {
		dev_err(sur40->dev, "image size mismatch\n");
		goto err_poll;
	}

	dev_dbg(sur40->dev, "header acquired\n");

	sgt = vb2_dma_sg_plane_desc(&new_buf->vb.vb2_buf, 0);

	result = usb_sg_init(&sgr, sur40->usbdev,
		usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT), 0,
		sgt->sgl, sgt->nents, sur40->pix_fmt.sizeimage, 0);
	if (result < 0) {
		dev_err(sur40->dev, "error %d in usb_sg_init\n", result);
		goto err_poll;
	}

	usb_sg_wait(&sgr);
	if (sgr.status < 0) {
		dev_err(sur40->dev, "error %d in usb_sg_wait\n", sgr.status);
		goto err_poll;
	}

	dev_dbg(sur40->dev, "image acquired\n");

	/* return error if streaming was stopped in the meantime */
	if (sur40->sequence == -1)
		return;

	/* mark as finished */
	new_buf->vb.vb2_buf.timestamp = ktime_get_ns();
	new_buf->vb.sequence = sur40->sequence++;
	new_buf->vb.field = V4L2_FIELD_NONE;
	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
	dev_dbg(sur40->dev, "buffer marked done\n");
	return;

err_poll:
	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
}

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/* Initialize input device parameters. */


static void sur40_input_setup(struct input_dev *input_dev)
{
	__set_bit(EV_KEY, input_dev->evbit);
	__set_bit(EV_ABS, input_dev->evbit);

	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
			     0, SENSOR_RES_X, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
			     0, SENSOR_RES_Y, 0, 0);

	input_set_abs_params(input_dev, ABS_MT_TOOL_X,
			     0, SENSOR_RES_X, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_TOOL_Y,
			     0, SENSOR_RES_Y, 0, 0);

	/* max value unknown, but major/minor axis
         * can never be larger than screen */
	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
			     0, SENSOR_RES_X, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
			     0, SENSOR_RES_Y, 0, 0);

	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);

	input_mt_init_slots(input_dev, MAX_CONTACTS,
			    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
}

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/* Check candidate USB interface. */


static int sur40_probe(struct usb_interface *interface,
		       const struct usb_device_id *id)
{
	struct usb_device *usbdev = interface_to_usbdev(interface);
	struct sur40_state *sur40;
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor *endpoint;
	struct input_polled_dev *poll_dev;
	int error;

	/* Check if we really have the right interface. */
	iface_desc = &interface->altsetting[0];
	if (iface_desc->desc.bInterfaceClass != 0xFF)
		return -ENODEV;

	if (iface_desc->desc.bNumEndpoints < 5)
		return -ENODEV;

	/* Use endpoint #4 (0x86). */
	endpoint = &iface_desc->endpoint[4].desc;
	if (endpoint->bEndpointAddress != TOUCH_ENDPOINT)
		return -ENODEV;

	/* Allocate memory for our device state and initialize it. */
	sur40 = kzalloc(sizeof(struct sur40_state), GFP_KERNEL);
	if (!sur40)
		return -ENOMEM;

	poll_dev = input_allocate_polled_device();
	if (!poll_dev) {
		error = -ENOMEM;
		goto err_free_dev;
	}

	/* initialize locks/lists */
	INIT_LIST_HEAD(&sur40->buf_list);
	spin_lock_init(&sur40->qlock);
	mutex_init(&sur40->lock);

	/* Set up polled input device control structure */
	poll_dev->private = sur40;
	poll_dev->poll_interval = POLL_INTERVAL;
	poll_dev->open = sur40_open;
	poll_dev->poll = sur40_poll;
	poll_dev->close = sur40_close;

	/* Set up regular input device structure */
	sur40_input_setup(poll_dev->input);

	poll_dev->input->name = DRIVER_LONG;
	usb_to_input_id(usbdev, &poll_dev->input->id);
	usb_make_path(usbdev, sur40->phys, sizeof(sur40->phys));
	strlcat(sur40->phys, "/input0", sizeof(sur40->phys));
	poll_dev->input->phys = sur40->phys;
	poll_dev->input->dev.parent = &interface->dev;

	sur40->usbdev = usbdev;
	sur40->dev = &interface->dev;
	sur40->input = poll_dev;

	/* use the bulk-in endpoint tested above */
	sur40->bulk_in_size = usb_endpoint_maxp(endpoint);
	sur40->bulk_in_epaddr = endpoint->bEndpointAddress;
	sur40->bulk_in_buffer = kmalloc(sur40->bulk_in_size, GFP_KERNEL);
	if (!sur40->bulk_in_buffer) {
		dev_err(&interface->dev, "Unable to allocate input buffer.");
		error = -ENOMEM;
		goto err_free_polldev;
	}

	/* register the polled input device */
	error = input_register_polled_device(poll_dev);
	if (error) {
		dev_err(&interface->dev,
			"Unable to register polled input device.");
		goto err_free_buffer;
	}

	/* register the video master device */
	snprintf(sur40->v4l2.name, sizeof(sur40->v4l2.name), "%s", DRIVER_LONG);
	error = v4l2_device_register(sur40->dev, &sur40->v4l2);
	if (error) {
		dev_err(&interface->dev,
			"Unable to register video master device.");
		goto err_unreg_v4l2;
	}

	/* initialize the lock and subdevice */
	sur40->queue = sur40_queue;
	sur40->queue.drv_priv = sur40;
	sur40->queue.lock = &sur40->lock;
	sur40->queue.dev = sur40->dev;

	/* initialize the queue */
	error = vb2_queue_init(&sur40->queue);
	if (error)
		goto err_unreg_v4l2;

	sur40->pix_fmt = sur40_pix_format[0];
	sur40->vdev = sur40_video_device;
	sur40->vdev.v4l2_dev = &sur40->v4l2;
	sur40->vdev.lock = &sur40->lock;
	sur40->vdev.queue = &sur40->queue;
	video_set_drvdata(&sur40->vdev, sur40);

	error = video_register_device(&sur40->vdev, VFL_TYPE_TOUCH, -1);
	if (error) {
		dev_err(&interface->dev,
			"Unable to register video subdevice.");
		goto err_unreg_video;
	}

	/* we can register the device now, as it is ready */
	usb_set_intfdata(interface, sur40);
	dev_dbg(&interface->dev, "%s is now attached\n", DRIVER_DESC);

	return 0;

err_unreg_video:
	video_unregister_device(&sur40->vdev);
err_unreg_v4l2:
	v4l2_device_unregister(&sur40->v4l2);
err_free_buffer:
	kfree(sur40->bulk_in_buffer);
err_free_polldev:
	input_free_polled_device(sur40->input);
err_free_dev:
	kfree(sur40);

	return error;
}

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Hans Verkuil
10
1.48%
1
20.00%
Nick Dyer
10
1.48%
1
20.00%
Julia Lawall
7
1.04%
1
20.00%
Total
675
100.00%
5
100.00%

/* Unregister device & clean up. */


static void sur40_disconnect(struct usb_interface *interface)
{
	struct sur40_state *sur40 = usb_get_intfdata(interface);

	video_unregister_device(&sur40->vdev);
	v4l2_device_unregister(&sur40->v4l2);

	input_unregister_polled_device(sur40->input);
	input_free_polled_device(sur40->input);
	kfree(sur40->bulk_in_buffer);
	kfree(sur40);

	usb_set_intfdata(interface, NULL);
	dev_dbg(&interface->dev, "%s is now disconnected\n", DRIVER_DESC);
}

Contributors
Person
Tokens
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CommitProp
Florian Echtler
82
100.00%
2
100.00%
Total
82
100.00%
2
100.00%

/*
 * Setup the constraints of the queue: besides setting the number of planes
 * per buffer and the size and allocation context of each plane, it also
 * checks if sufficient buffers have been allocated. Usually 3 is a good
 * minimum number: many DMA engines need a minimum of 2 buffers in the
 * queue and you need to have another available for userspace processing.
 */


static int sur40_queue_setup(struct vb2_queue *q,
		       unsigned int *nbuffers, unsigned int *nplanes,
		       unsigned int sizes[], struct device *alloc_devs[])
{
	struct sur40_state *sur40 = vb2_get_drv_priv(q);

	if (q->num_buffers + *nbuffers < 3)
		*nbuffers = 3 - q->num_buffers;

	if (*nplanes)
		return sizes[0] < sur40->pix_fmt.sizeimage ? -EINVAL : 0;

	*nplanes = 1