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 /* Driver data */
  88 struct huion_drvdata {
  89         __u8 *rdesc;
  90         unsigned int rsize;
  91 };
  92
  93 static __u8 *huion_report_fixup(struct hid_device *hdev, __u8 *rdesc,
  94                 unsigned int *rsize)
  95 {
  96         struct huion_drvdata *drvdata = hid_get_drvdata(hdev);
  97         switch (hdev->product) {
  98         case USB_DEVICE_ID_HUION_TABLET:
  99                 if (drvdata->rdesc != NULL) {
 100                         rdesc = drvdata->rdesc;
 101                         *rsize = drvdata->rsize;
 102                 }
 103                 break;
 104         }
 105         return rdesc;
 106 }
 107
 108 /**
 109  * Enable fully-functional tablet mode and determine device parameters.
 110  *
 111  * @hdev:       HID device
 112  */
 113 static int huion_tablet_enable(struct hid_device *hdev)
 114 {
 115         int rc;
 116         struct usb_device *usb_dev = hid_to_usb_dev(hdev);
 117         struct huion_drvdata *drvdata = hid_get_drvdata(hdev);
 118         __le16 buf[6];
 119
 120         /*
 121          * Read string descriptor containing tablet parameters. The specific
 122          * string descriptor and data were discovered by sniffing the Windows
 123          * driver traffic.
 124          * NOTE: This enables fully-functional tablet mode.
 125          */
 126         rc = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
 127                                 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
 128                                 (USB_DT_STRING << 8) + 0x64,
 129                                 0x0409, buf, sizeof(buf),
 130                                 USB_CTRL_GET_TIMEOUT);
 131         if (rc == -EPIPE)
 132                 hid_warn(hdev, "device parameters not found\n");
 133         else if (rc < 0)
 134                 hid_warn(hdev, "failed to get device parameters: %d\n", rc);
 135         else if (rc != sizeof(buf))
 136                 hid_warn(hdev, "invalid device parameters\n");
 137         else {
 138                 s32 params[HUION_PH_ID_NUM];
 139                 s32 resolution;
 140                 __u8 *p;
 141                 s32 v;
 142
 143                 /* Extract device parameters */
 144                 params[HUION_PH_ID_X_LM] = le16_to_cpu(buf[1]);
 145                 params[HUION_PH_ID_Y_LM] = le16_to_cpu(buf[2]);
 146                 params[HUION_PH_ID_PRESSURE_LM] = le16_to_cpu(buf[4]);
 147                 resolution = le16_to_cpu(buf[5]);
 148                 if (resolution == 0) {
 149                         params[HUION_PH_ID_X_PM] = 0;
 150                         params[HUION_PH_ID_Y_PM] = 0;
 151                 } else {
 152                         params[HUION_PH_ID_X_PM] = params[HUION_PH_ID_X_LM] *
 153                                                         1000 / resolution;
 154                         params[HUION_PH_ID_Y_PM] = params[HUION_PH_ID_Y_LM] *
 155                                                         1000 / resolution;
 156                 }
 157
 158                 /* Allocate fixed report descriptor */
 159                 drvdata->rdesc = devm_kmalloc(&hdev->dev,
 160                                         sizeof(huion_tablet_rdesc_template),
 161                                         GFP_KERNEL);
 162                 if (drvdata->rdesc == NULL) {
 163                         hid_err(hdev, "failed to allocate fixed rdesc\n");
 164                         return -ENOMEM;
 165                 }
 166                 drvdata->rsize = sizeof(huion_tablet_rdesc_template);
 167
 168                 /* Format fixed report descriptor */
 169                 memcpy(drvdata->rdesc, huion_tablet_rdesc_template,
 170                         drvdata->rsize);
 171                 for (p = drvdata->rdesc;
 172                      p <= drvdata->rdesc + drvdata->rsize - 4;) {
 173                         if (p[0] == 0xFE && p[1] == 0xED && p[2] == 0x1D &&
 174                             p[3] < sizeof(params)) {
 175                                 v = params[p[3]];
 176                                 put_unaligned(cpu_to_le32(v), (s32 *)p);
 177                                 p += 4;
 178                         } else {
 179                                 p++;
 180                         }
 181                 }
 182         }
 183
 184         return 0;
 185 }
 186
 187 static int huion_probe(struct hid_device *hdev, const struct hid_device_id *id)
 188 {
 189         int rc;
 190         struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
 191         struct huion_drvdata *drvdata;
 192
 193         /* Allocate and assign driver data */
 194         drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
 195         if (drvdata == NULL) {
 196                 hid_err(hdev, "failed to allocate driver data\n");
 197                 return -ENOMEM;
 198         }
 199         hid_set_drvdata(hdev, drvdata);
 200
 201         switch (id->product) {
 202         case USB_DEVICE_ID_HUION_TABLET:
 203                 /* If this is the pen interface */
 204                 if (intf->cur_altsetting->desc.bInterfaceNumber == 0) {
 205                         rc = huion_tablet_enable(hdev);
 206                         if (rc) {
 207                                 hid_err(hdev, "tablet enabling failed\n");
 208                                 return rc;
 209                         }
 210                 }
 211                 break;
 212         }
 213
 214         rc = hid_parse(hdev);
 215         if (rc) {
 216                 hid_err(hdev, "parse failed\n");
 217                 return rc;
 218         }
 219
 220         rc = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 221         if (rc) {
 222                 hid_err(hdev, "hw start failed\n");
 223                 return rc;
 224         }
 225
 226         return 0;
 227 }
 228
 229 static int huion_raw_event(struct hid_device *hdev, struct hid_report *report,
 230                         u8 *data, int size)
 231 {
 232         struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
 233
 234         /* If this is a pen input report */
 235         if (intf->cur_altsetting->desc.bInterfaceNumber == 0 &&
 236             report->type == HID_INPUT_REPORT &&
 237             report->id == 0x07 && size >= 2)
 238                 /* Invert the in-range bit */
 239                 data[1] ^= 0x40;
 240
 241         return 0;
 242 }
 243
 244 static const struct hid_device_id huion_devices[] = {
 245         { HID_USB_DEVICE(USB_VENDOR_ID_HUION, USB_DEVICE_ID_HUION_TABLET) },
 246         { HID_USB_DEVICE(USB_VENDOR_ID_UCLOGIC, USB_DEVICE_ID_HUION_TABLET) },
 247         { }
 248 };
 249 MODULE_DEVICE_TABLE(hid, huion_devices);
 250
 251 static struct hid_driver huion_driver = {
 252         .name = "huion",
 253         .id_table = huion_devices,
 254         .probe = huion_probe,
 255         .report_fixup = huion_report_fixup,
 256         .raw_event = huion_raw_event,
 257 };
 258 module_hid_driver(huion_driver);
 259
 260 MODULE_AUTHOR("Martin Rusko");
 261 MODULE_DESCRIPTION("Huion HID driver");
 262 MODULE_LICENSE("GPL");