drivers/hid/hid-huion.c

   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 */
  28 enum 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 */
  41 static 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 */
  88 enum 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 */
  97 struct huion_drvdata {
  98         __u8 *rdesc;
  99         unsigned int rsize;
 100 };
 101
 102 static __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  */
 122 static 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
 210 cleanup:
 211         kfree(buf);
 212         return rc;
 213 }
 214
 215 static 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
 257 static 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
 272 static 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 };
 277 MODULE_DEVICE_TABLE(hid, huion_devices);
 278
 279 static 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 };
 286 module_hid_driver(huion_driver);
 287
 288 MODULE_AUTHOR("Martin Rusko");
 289 MODULE_DESCRIPTION("Huion HID driver");
 290 MODULE_LICENSE("GPL");