HID: Add driver for Holtek based keyboards with broken HID

Corrects two HID descriptor issues, which prevent some Holtek based
(USB ID 04d9:a055) keyboards from working. The error when not using
the driver is: generic-usb: probe ... failed with error -22 .

Signed-off-by: Tom Harwood <tomharwood@fastmail.fm>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

5 files changed, 192 insertions, 2 deletions

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index cbf0e0344e3e..8e439e290fc4 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -200,10 +200,12 @@ config HID_EZKEY
         Support for Ezkey BTC 8193 keyboard.
 
 config HID_HOLTEK
-        tristate "Holtek On Line Grip based game controller support"
+        tristate "Holtek HID devices"
         depends on USB_HID
         ---help---
-          Say Y here if you have a Holtek On Line Grip based game controller.
+        Support for Holtek based devices:
+          - Holtek On Line Grip based game controller
+          - Trust GXT 18 Gaming Keyboard
 
 config HOLTEK_FF
         bool "Holtek On Line Grip force feedback support"
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 05913c533ec5..2429ae7c58c0 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_HID_EMS_FF)	+= hid-emsff.o
 obj-$(CONFIG_HID_ELECOM)        += hid-elecom.o
 obj-$(CONFIG_HID_EZKEY)         += hid-ezkey.o
 obj-$(CONFIG_HID_GYRATION)      += hid-gyration.o
+obj-$(CONFIG_HID_HOLTEK)        += hid-holtek-kbd.o
 obj-$(CONFIG_HID_HOLTEK)        += hid-holtekff.o
 obj-$(CONFIG_HID_HYPERV_MOUSE)  += hid-hyperv.o
 obj-$(CONFIG_HID_KENSINGTON)    += hid-kensington.o
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index f69568032c04..ba1c3644e6ac 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1536,6 +1536,7 @@ static const struct hid_device_id hid_have_special_driver[] = {
         { HID_USB_DEVICE(USB_VENDOR_ID_GYRATION, USB_DEVICE_ID_GYRATION_REMOTE_2) },
         { HID_USB_DEVICE(USB_VENDOR_ID_GYRATION, USB_DEVICE_ID_GYRATION_REMOTE_3) },
         { HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK, USB_DEVICE_ID_HOLTEK_ON_LINE_GRIP) },
+        { HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK_ALT, USB_DEVICE_ID_HOLTEK_ALT_KEYBOARD) },
         { HID_USB_DEVICE(USB_VENDOR_ID_KENSINGTON, USB_DEVICE_ID_KS_SLIMBLADE) },
         { HID_USB_DEVICE(USB_VENDOR_ID_KEYTOUCH, USB_DEVICE_ID_KEYTOUCH_IEC) },
         { HID_USB_DEVICE(USB_VENDOR_ID_KYE, USB_DEVICE_ID_KYE_ERGO_525V) },
diff --git a/drivers/hid/hid-holtek-kbd.c b/drivers/hid/hid-holtek-kbd.c
new file mode 100644
index 000000000000..e0a5d1739fc3
--- /dev/null
+++ b/drivers/hid/hid-holtek-kbd.c
@@ -0,0 +1,183 @@
+/*
+ * HID driver for Holtek keyboard
+ * Copyright (c) 2012 Tom Harwood
+*/
+
+/*
+ * 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/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+
+#include "hid-ids.h"
+#include "usbhid/usbhid.h"
+
+/* Holtek based keyboards (USB ID 04d9:a055) have the following issues:
+ * - The report descriptor specifies an excessively large number of consumer
+ *   usages (2^15), which is more than HID_MAX_USAGES. This prevents proper
+ *   parsing of the report descriptor.
+ * - The report descriptor reports on caps/scroll/num lock key presses, but
+ *   doesn't have an LED output usage block.
+ *
+ * The replacement descriptor below fixes the number of consumer usages,
+ * and provides an LED output usage block. LED output events are redirected
+ * to the boot interface.
+ */
+
+static __u8 holtek_kbd_rdesc_fixed[] = {
+        /* Original report descriptor, with reduced number of consumer usages */
+        0x05, 0x01,         /*  Usage Page (Desktop),                         */
+        0x09, 0x80,         /*  Usage (Sys Control),                          */
+        0xA1, 0x01,         /*  Collection (Application),                     */
+        0x85, 0x01,         /*      Report ID (1),                            */
+        0x19, 0x81,         /*      Usage Minimum (Sys Power Down),           */
+        0x29, 0x83,         /*      Usage Maximum (Sys Wake Up),              */
+        0x15, 0x00,         /*      Logical Minimum (0),                      */
+        0x25, 0x01,         /*      Logical Maximum (1),                      */
+        0x95, 0x03,         /*      Report Count (3),                         */
+        0x75, 0x01,         /*      Report Size (1),                          */
+        0x81, 0x02,         /*      Input (Variable),                         */
+        0x95, 0x01,         /*      Report Count (1),                         */
+        0x75, 0x05,         /*      Report Size (5),                          */
+        0x81, 0x01,         /*      Input (Constant),                         */
+        0xC0,               /*  End Collection,                               */
+        0x05, 0x0C,         /*  Usage Page (Consumer),                        */
+        0x09, 0x01,         /*  Usage (Consumer Control),                     */
+        0xA1, 0x01,         /*  Collection (Application),                     */
+        0x85, 0x02,         /*      Report ID (2),                            */
+        0x19, 0x00,         /*      Usage Minimum (00h),                      */
+        0x2A, 0xFF, 0x2F,   /*      Usage Maximum (0x2FFF), previously 0x7FFF */
+        0x15, 0x00,         /*      Logical Minimum (0),                      */
+        0x26, 0xFF, 0x2F,   /*      Logical Maximum (0x2FFF),previously 0x7FFF*/
+        0x95, 0x01,         /*      Report Count (1),                         */
+        0x75, 0x10,         /*      Report Size (16),                         */
+        0x81, 0x00,         /*      Input,                                    */
+        0xC0,               /*  End Collection,                               */
+        0x05, 0x01,         /*  Usage Page (Desktop),                         */
+        0x09, 0x06,         /*  Usage (Keyboard),                             */
+        0xA1, 0x01,         /*  Collection (Application),                     */
+        0x85, 0x03,         /*      Report ID (3),                            */
+        0x95, 0x38,         /*      Report Count (56),                        */
+        0x75, 0x01,         /*      Report Size (1),                          */
+        0x15, 0x00,         /*      Logical Minimum (0),                      */
+        0x25, 0x01,         /*      Logical Maximum (1),                      */
+        0x05, 0x07,         /*      Usage Page (Keyboard),                    */
+        0x19, 0xE0,         /*      Usage Minimum (KB Leftcontrol),           */
+        0x29, 0xE7,         /*      Usage Maximum (KB Right GUI),             */
+        0x19, 0x00,         /*      Usage Minimum (None),                     */
+        0x29, 0x2F,         /*      Usage Maximum (KB Lboxbracket And Lbrace),*/
+        0x81, 0x02,         /*      Input (Variable),                         */
+        0xC0,               /*  End Collection,                               */
+        0x05, 0x01,         /*  Usage Page (Desktop),                         */
+        0x09, 0x06,         /*  Usage (Keyboard),                             */
+        0xA1, 0x01,         /*  Collection (Application),                     */
+        0x85, 0x04,         /*      Report ID (4),                            */
+        0x95, 0x38,         /*      Report Count (56),                        */
+        0x75, 0x01,         /*      Report Size (1),                          */
+        0x15, 0x00,         /*      Logical Minimum (0),                      */
+        0x25, 0x01,         /*      Logical Maximum (1),                      */
+        0x05, 0x07,         /*      Usage Page (Keyboard),                    */
+        0x19, 0x30,         /*      Usage Minimum (KB Rboxbracket And Rbrace),*/
+        0x29, 0x67,         /*      Usage Maximum (KP Equals),                */
+        0x81, 0x02,         /*      Input (Variable),                         */
+        0xC0,               /*  End Collection                                */
+
+        /* LED usage for the boot protocol interface */
+        0x05, 0x01,         /*  Usage Page (Desktop),                         */
+        0x09, 0x06,         /*  Usage (Keyboard),                             */
+        0xA1, 0x01,         /*  Collection (Application),                     */
+        0x05, 0x08,         /*      Usage Page (LED),                         */
+        0x19, 0x01,         /*      Usage Minimum (01h),                      */
+        0x29, 0x03,         /*      Usage Maximum (03h),                      */
+        0x15, 0x00,         /*      Logical Minimum (0),                      */
+        0x25, 0x01,         /*      Logical Maximum (1),                      */
+        0x75, 0x01,         /*      Report Size (1),                          */
+        0x95, 0x03,         /*      Report Count (3),                         */
+        0x91, 0x02,         /*      Output (Variable),                        */
+        0x95, 0x05,         /*      Report Count (5),                         */
+        0x91, 0x01,         /*      Output (Constant),                        */
+        0xC0,               /*  End Collection                                */
+};
+
+static __u8 *holtek_kbd_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+                unsigned int *rsize)
+{
+        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
+
+        if (intf->cur_altsetting->desc.bInterfaceNumber == 1) {
+                rdesc = holtek_kbd_rdesc_fixed;
+                *rsize = sizeof(holtek_kbd_rdesc_fixed);
+        }
+        return rdesc;
+}
+
+static int holtek_kbd_input_event(struct input_dev *dev, unsigned int type,
+                unsigned int code,
+                int value)
+{
+        struct hid_device *hid = input_get_drvdata(dev);
+        struct usb_device *usb_dev = hid_to_usb_dev(hid);
+
+        /* Locate the boot interface, to receive the LED change events */
+        struct usb_interface *boot_interface = usb_ifnum_to_if(usb_dev, 0);
+
+        struct hid_device *boot_hid = usb_get_intfdata(boot_interface);
+        struct hid_input *boot_hid_input = list_first_entry(&boot_hid->inputs,
+                struct hid_input, list);
+
+        return boot_hid_input->input->event(boot_hid_input->input, type, code,
+                        value);
+}
+
+static int holtek_kbd_probe(struct hid_device *hdev,
+                const struct hid_device_id *id)
+{
+        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
+        int ret = hid_parse(hdev);
+
+        if (!ret)
+                ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+
+        if (!ret && intf->cur_altsetting->desc.bInterfaceNumber == 1) {
+                struct hid_input *hidinput;
+                list_for_each_entry(hidinput, &hdev->inputs, list) {
+                        hidinput->input->event = holtek_kbd_input_event;
+                }
+        }
+
+        return ret;
+}
+
+static const struct hid_device_id holtek_kbd_devices[] = {
+        { HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK_ALT,
+                        USB_DEVICE_ID_HOLTEK_ALT_KEYBOARD) },
+        { }
+};
+MODULE_DEVICE_TABLE(hid, holtek_kbd_devices);
+
+static struct hid_driver holtek_kbd_driver = {
+        .name = "holtek_kbd",
+        .id_table = holtek_kbd_devices,
+        .report_fixup = holtek_kbd_report_fixup,
+        .probe = holtek_kbd_probe
+};
+
+static int __init holtek_kbd_init(void)
+{
+        return hid_register_driver(&holtek_kbd_driver);
+}
+
+static void __exit holtek_kbd_exit(void)
+{
+        hid_unregister_driver(&holtek_kbd_driver);
+}
+
+module_exit(holtek_kbd_exit);
+module_init(holtek_kbd_init);
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index c607e6f33953..a139d9619ad1 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -404,6 +404,9 @@
 #define USB_VENDOR_ID_HOLTEK            0x1241
 #define USB_DEVICE_ID_HOLTEK_ON_LINE_GRIP       0x5015
 
+#define USB_VENDOR_ID_HOLTEK_ALT                0x04d9
+#define USB_DEVICE_ID_HOLTEK_ALT_KEYBOARD       0xa055
+
 #define USB_VENDOR_ID_IMATION           0x0718
 #define USB_DEVICE_ID_DISC_STAKKA       0xd000