/*
* Surface2.0/SUR40/PixelSense input driver
*
* Copyright (c) 2013 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>
*
* 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>
/* 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;
/* version information */
#define DRIVER_SHORT "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
/* polling interval (ms) */
#define POLL_INTERVAL 10
/* 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 */
/*
* 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
*/
struct sur40_state {
struct usb_device *usbdev;
struct device *dev;
struct input_polled_dev *input;
struct sur40_data *bulk_in_buffer;
size_t bulk_in_size;
u8 bulk_in_epaddr;
char phys[64];
};
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);
}
/* Initialization routine, called from sur40_open */
static int sur40_init(struct sur40_state *dev)
{
int result;
u8 buffer[24];
/* stupidly replay the original MS driver init sequence */
result = sur40_command(dev, SUR40_GET_VERSION, 0x00, buffer, 12);
if (result < 0)
return result;
result = sur40_command(dev, SUR40_GET_VERSION, 0x01, buffer, 12);
if (result < 0)
return result;
result = sur40_command(dev, SUR40_GET_VERSION, 0x02, buffer, 12);
if (result < 0)
return result;
result = sur40_command(dev, SUR40_UNKNOWN2, 0x00, buffer, 24);
if (result < 0)
return result;
result = sur40_command(dev, SUR40_UNKNOWN1, 0x00, buffer, 5);
if (result < 0)
return result;
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...
*/
return result;
}
/*
* 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);
}
/* 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.
*/
}
/*
* 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);
}
/* 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_warn(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);
}
/* 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);
}
/* 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;
/* 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;
}
/* 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 = "Samsung SUR40";
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;
}
error = input_register_polled_device(poll_dev);
if (error) {
dev_err(&interface->dev,
"Unable to register polled input device.");
goto err_free_buffer;
}
/* 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_free_buffer:
kfree(sur40->bulk_in_buffer);
err_free_polldev:
input_free_polled_device(sur40->input);
err_free_dev:
kfree(sur40);
return error;
}
/* Unregister device & clean up. */
static void sur40_disconnect(struct usb_interface *interface)
{
struct sur40_state *sur40 = usb_get_intfdata(interface);
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);
}
static const struct usb_device_id sur40_table[] = {
{ USB_DEVICE(ID_MICROSOFT, ID_SUR40) }, /* Samsung SUR40 */
{ } /* terminating null entry */
};
MODULE_DEVICE_TABLE(usb, sur40_table);
/* USB-specific object needed to register this driver with the USB subsystem. */
static struct usb_driver sur40_driver = {
.name = DRIVER_SHORT,
.probe = sur40_probe,
.disconnect = sur40_disconnect,
.id_table = sur40_table,
};
module_usb_driver(sur40_driver);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
