linux/drivers/hid/hid-huion.c
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   1/*
   2 *  HID driver for Huion devices not fully compliant with HID standard
   3 *
   4 *  Copyright (c) 2013 Martin Rusko
   5 *  Copyright (c) 2014 Nikolai Kondrashov
   6 */
   7
   8/*
   9 * This program is free software; you can redistribute it and/or modify it
  10 * under the terms of the GNU General Public License as published by the Free
  11 * Software Foundation; either version 2 of the License, or (at your option)
  12 * any later version.
  13 */
  14
  15#include <linux/device.h>
  16#include <linux/hid.h>
  17#include <linux/module.h>
  18#include <linux/usb.h>
  19#include <asm/unaligned.h>
  20#include "usbhid/usbhid.h"
  21
  22#include "hid-ids.h"
  23
  24/* Report descriptor template placeholder head */
  25#define HUION_PH_HEAD   0xFE, 0xED, 0x1D
  26
  27/* Report descriptor template placeholder IDs */
  28enum huion_ph_id {
  29        HUION_PH_ID_X_LM,
  30        HUION_PH_ID_X_PM,
  31        HUION_PH_ID_Y_LM,
  32        HUION_PH_ID_Y_PM,
  33        HUION_PH_ID_PRESSURE_LM,
  34        HUION_PH_ID_NUM
  35};
  36
  37/* Report descriptor template placeholder */
  38#define HUION_PH(_ID) HUION_PH_HEAD, HUION_PH_ID_##_ID
  39
  40/* Fixed report descriptor template */
  41static const __u8 huion_tablet_rdesc_template[] = {
  42        0x05, 0x0D,             /*  Usage Page (Digitizer),                 */
  43        0x09, 0x02,             /*  Usage (Pen),                            */
  44        0xA1, 0x01,             /*  Collection (Application),               */
  45        0x85, 0x07,             /*      Report ID (7),                      */
  46        0x09, 0x20,             /*      Usage (Stylus),                     */
  47        0xA0,                   /*      Collection (Physical),              */
  48        0x14,                   /*          Logical Minimum (0),            */
  49        0x25, 0x01,             /*          Logical Maximum (1),            */
  50        0x75, 0x01,             /*          Report Size (1),                */
  51        0x09, 0x42,             /*          Usage (Tip Switch),             */
  52        0x09, 0x44,             /*          Usage (Barrel Switch),          */
  53        0x09, 0x46,             /*          Usage (Tablet Pick),            */
  54        0x95, 0x03,             /*          Report Count (3),               */
  55        0x81, 0x02,             /*          Input (Variable),               */
  56        0x95, 0x03,             /*          Report Count (3),               */
  57        0x81, 0x03,             /*          Input (Constant, Variable),     */
  58        0x09, 0x32,             /*          Usage (In Range),               */
  59        0x95, 0x01,             /*          Report Count (1),               */
  60        0x81, 0x02,             /*          Input (Variable),               */
  61        0x95, 0x01,             /*          Report Count (1),               */
  62        0x81, 0x03,             /*          Input (Constant, Variable),     */
  63        0x75, 0x10,             /*          Report Size (16),               */
  64        0x95, 0x01,             /*          Report Count (1),               */
  65        0xA4,                   /*          Push,                           */
  66        0x05, 0x01,             /*          Usage Page (Desktop),           */
  67        0x65, 0x13,             /*          Unit (Inch),                    */
  68        0x55, 0xFD,             /*          Unit Exponent (-3),             */
  69        0x34,                   /*          Physical Minimum (0),           */
  70        0x09, 0x30,             /*          Usage (X),                      */
  71        0x27, HUION_PH(X_LM),   /*          Logical Maximum (PLACEHOLDER),  */
  72        0x47, HUION_PH(X_PM),   /*          Physical Maximum (PLACEHOLDER), */
  73        0x81, 0x02,             /*          Input (Variable),               */
  74        0x09, 0x31,             /*          Usage (Y),                      */
  75        0x27, HUION_PH(Y_LM),   /*          Logical Maximum (PLACEHOLDER),  */
  76        0x47, HUION_PH(Y_PM),   /*          Physical Maximum (PLACEHOLDER), */
  77        0x81, 0x02,             /*          Input (Variable),               */
  78        0xB4,                   /*          Pop,                            */
  79        0x09, 0x30,             /*          Usage (Tip Pressure),           */
  80        0x27,
  81        HUION_PH(PRESSURE_LM),  /*          Logical Maximum (PLACEHOLDER),  */
  82        0x81, 0x02,             /*          Input (Variable),               */
  83        0xC0,                   /*      End Collection,                     */
  84        0xC0                    /*  End Collection                          */
  85};
  86
  87/* Parameter indices */
  88enum huion_prm {
  89        HUION_PRM_X_LM          = 1,
  90        HUION_PRM_Y_LM          = 2,
  91        HUION_PRM_PRESSURE_LM   = 4,
  92        HUION_PRM_RESOLUTION    = 5,
  93        HUION_PRM_NUM
  94};
  95
  96/* Driver data */
  97struct huion_drvdata {
  98        __u8 *rdesc;
  99        unsigned int rsize;
 100};
 101
 102static __u8 *huion_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 103                unsigned int *rsize)
 104{
 105        struct huion_drvdata *drvdata = hid_get_drvdata(hdev);
 106        switch (hdev->product) {
 107        case USB_DEVICE_ID_HUION_TABLET:
 108                if (drvdata->rdesc != NULL) {
 109                        rdesc = drvdata->rdesc;
 110                        *rsize = drvdata->rsize;
 111                }
 112                break;
 113        }
 114        return rdesc;
 115}
 116
 117/**
 118 * Enable fully-functional tablet mode and determine device parameters.
 119 *
 120 * @hdev:       HID device
 121 */
 122static int huion_tablet_enable(struct hid_device *hdev)
 123{
 124        int rc;
 125        struct usb_device *usb_dev = hid_to_usb_dev(hdev);
 126        struct huion_drvdata *drvdata = hid_get_drvdata(hdev);
 127        __le16 *buf = NULL;
 128        size_t len;
 129        s32 params[HUION_PH_ID_NUM];
 130        s32 resolution;
 131        __u8 *p;
 132        s32 v;
 133
 134        /*
 135         * Read string descriptor containing tablet parameters. The specific
 136         * string descriptor and data were discovered by sniffing the Windows
 137         * driver traffic.
 138         * NOTE: This enables fully-functional tablet mode.
 139         */
 140        len = HUION_PRM_NUM * sizeof(*buf);
 141        buf = kmalloc(len, GFP_KERNEL);
 142        if (buf == NULL) {
 143                hid_err(hdev, "failed to allocate parameter buffer\n");
 144                rc = -ENOMEM;
 145                goto cleanup;
 146        }
 147        rc = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
 148                                USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
 149                                (USB_DT_STRING << 8) + 0x64,
 150                                0x0409, buf, len,
 151                                USB_CTRL_GET_TIMEOUT);
 152        if (rc == -EPIPE) {
 153                hid_err(hdev, "device parameters not found\n");
 154                rc = -ENODEV;
 155                goto cleanup;
 156        } else if (rc < 0) {
 157                hid_err(hdev, "failed to get device parameters: %d\n", rc);
 158                rc = -ENODEV;
 159                goto cleanup;
 160        } else if (rc != len) {
 161                hid_err(hdev, "invalid device parameters\n");
 162                rc = -ENODEV;
 163                goto cleanup;
 164        }
 165
 166        /* Extract device parameters */
 167        params[HUION_PH_ID_X_LM] = le16_to_cpu(buf[HUION_PRM_X_LM]);
 168        params[HUION_PH_ID_Y_LM] = le16_to_cpu(buf[HUION_PRM_Y_LM]);
 169        params[HUION_PH_ID_PRESSURE_LM] =
 170                le16_to_cpu(buf[HUION_PRM_PRESSURE_LM]);
 171        resolution = le16_to_cpu(buf[HUION_PRM_RESOLUTION]);
 172        if (resolution == 0) {
 173                params[HUION_PH_ID_X_PM] = 0;
 174                params[HUION_PH_ID_Y_PM] = 0;
 175        } else {
 176                params[HUION_PH_ID_X_PM] = params[HUION_PH_ID_X_LM] *
 177                                                1000 / resolution;
 178                params[HUION_PH_ID_Y_PM] = params[HUION_PH_ID_Y_LM] *
 179                                                1000 / resolution;
 180        }
 181
 182        /* Allocate fixed report descriptor */
 183        drvdata->rdesc = devm_kmalloc(&hdev->dev,
 184                                sizeof(huion_tablet_rdesc_template),
 185                                GFP_KERNEL);
 186        if (drvdata->rdesc == NULL) {
 187                hid_err(hdev, "failed to allocate fixed rdesc\n");
 188                rc = -ENOMEM;
 189                goto cleanup;
 190        }
 191        drvdata->rsize = sizeof(huion_tablet_rdesc_template);
 192
 193        /* Format fixed report descriptor */
 194        memcpy(drvdata->rdesc, huion_tablet_rdesc_template,
 195                drvdata->rsize);
 196        for (p = drvdata->rdesc;
 197             p <= drvdata->rdesc + drvdata->rsize - 4;) {
 198                if (p[0] == 0xFE && p[1] == 0xED && p[2] == 0x1D &&
 199                    p[3] < sizeof(params)) {
 200                        v = params[p[3]];
 201                        put_unaligned(cpu_to_le32(v), (s32 *)p);
 202                        p += 4;
 203                } else {
 204                        p++;
 205                }
 206        }
 207
 208        rc = 0;
 209
 210cleanup:
 211        kfree(buf);
 212        return rc;
 213}
 214
 215static int huion_probe(struct hid_device *hdev, const struct hid_device_id *id)
 216{
 217        int rc;
 218        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
 219        struct huion_drvdata *drvdata;
 220
 221        /* Allocate and assign driver data */
 222        drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
 223        if (drvdata == NULL) {
 224                hid_err(hdev, "failed to allocate driver data\n");
 225                return -ENOMEM;
 226        }
 227        hid_set_drvdata(hdev, drvdata);
 228
 229        switch (id->product) {
 230        case USB_DEVICE_ID_HUION_TABLET:
 231                /* If this is the pen interface */
 232                if (intf->cur_altsetting->desc.bInterfaceNumber == 0) {
 233                        rc = huion_tablet_enable(hdev);
 234                        if (rc) {
 235                                hid_err(hdev, "tablet enabling failed\n");
 236                                return rc;
 237                        }
 238                }
 239                break;
 240        }
 241
 242        rc = hid_parse(hdev);
 243        if (rc) {
 244                hid_err(hdev, "parse failed\n");
 245                return rc;
 246        }
 247
 248        rc = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 249        if (rc) {
 250                hid_err(hdev, "hw start failed\n");
 251                return rc;
 252        }
 253
 254        return 0;
 255}
 256
 257static int huion_raw_event(struct hid_device *hdev, struct hid_report *report,
 258                        u8 *data, int size)
 259{
 260        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
 261
 262        /* If this is a pen input report */
 263        if (intf->cur_altsetting->desc.bInterfaceNumber == 0 &&
 264            report->type == HID_INPUT_REPORT &&
 265            report->id == 0x07 && size >= 2)
 266                /* Invert the in-range bit */
 267                data[1] ^= 0x40;
 268
 269        return 0;
 270}
 271
 272static const struct hid_device_id huion_devices[] = {
 273        { HID_USB_DEVICE(USB_VENDOR_ID_HUION, USB_DEVICE_ID_HUION_TABLET) },
 274        { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC, USB_DEVICE_ID_HUION_TABLET) },
 275        { }
 276};
 277MODULE_DEVICE_TABLE(hid, huion_devices);
 278
 279static struct hid_driver huion_driver = {
 280        .name = "huion",
 281        .id_table = huion_devices,
 282        .probe = huion_probe,
 283        .report_fixup = huion_report_fixup,
 284        .raw_event = huion_raw_event,
 285};
 286module_hid_driver(huion_driver);
 287
 288MODULE_AUTHOR("Martin Rusko");
 289MODULE_DESCRIPTION("Huion HID driver");
 290MODULE_LICENSE("GPL");
 291
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