HID: google: add google hammer HID driver

Add Google hammer HID driver. This driver allow us to control hammer
keyboard backlight and support future features.

Signed-off-by: Wei-Ning Huang <wnhuang@google.com>
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 19c499f5623d776576a51a8da4ea13395f76d69a..a18e06b81165963c0ab2b4b2d4c27327e8c089e0 100644 (file)
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -331,6 +331,12 @@ config HOLTEK_FF
          Say Y here if you have a Holtek On Line Grip based game controller
          and want to have force feedback support for it.
 
+config HID_GOOGLE_HAMMER
+       tristate "Google Hammer Keyboard"
+       depends on USB_HID && LEDS_CLASS
+       ---help---
+       Say Y here if you have a Google Hammer device.
+
 config HID_GT683R
        tristate "MSI GT68xR LED support"
        depends on LEDS_CLASS && USB_HID

diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index eb13b9e92d8528d01f9e8581b6d92eaa76a5b5d5..4e9b57a44e968b5f8a0f3e780d9ada934d1b4a43 100644 (file)
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_HID_ELO)         += hid-elo.o
 obj-$(CONFIG_HID_EZKEY)                += hid-ezkey.o
 obj-$(CONFIG_HID_GEMBIRD)      += hid-gembird.o
 obj-$(CONFIG_HID_GFRM)         += hid-gfrm.o
+obj-$(CONFIG_HID_GOOGLE_HAMMER)        += hid-google-hammer.o
 obj-$(CONFIG_HID_GT683R)       += hid-gt683r.o
 obj-$(CONFIG_HID_GYRATION)     += hid-gyration.o
 obj-$(CONFIG_HID_HOLTEK)       += hid-holtek-kbd.o

diff --git a/drivers/hid/hid-google-hammer.c b/drivers/hid/hid-google-hammer.c
new file mode 100644 (file)
index 0000000..6486469
--- /dev/null
+++ b/drivers/hid/hid-google-hammer.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  HID driver for Google Hammer device.
+ *
+ *  Copyright (c) 2017 Google Inc.
+ *  Author: Wei-Ning Huang <wnhuang@google.com>
+ */
+
+/*
+ * 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/hid.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define MAX_BRIGHTNESS 100
+
+/* HID usage for keyboard backlight (Alphanumeric display brightness) */
+#define HID_AD_BRIGHTNESS 0x00140046
+
+struct hammer_kbd_leds {
+       struct led_classdev cdev;
+       struct hid_device *hdev;
+       u8 buf[2] ____cacheline_aligned;
+};
+
+static int hammer_kbd_brightness_set_blocking(struct led_classdev *cdev,
+               enum led_brightness br)
+{
+       struct hammer_kbd_leds *led = container_of(cdev,
+                                                  struct hammer_kbd_leds,
+                                                  cdev);
+       int ret;
+
+       led->buf[0] = 0;
+       led->buf[1] = br;
+
+       ret = hid_hw_output_report(led->hdev, led->buf, sizeof(led->buf));
+       if (ret == -ENOSYS)
+               ret = hid_hw_raw_request(led->hdev, 0, led->buf,
+                                        sizeof(led->buf),
+                                        HID_OUTPUT_REPORT,
+                                        HID_REQ_SET_REPORT);
+       if (ret < 0)
+               hid_err(led->hdev, "failed to set keyboard backlight: %d\n",
+                       ret);
+       return ret;
+}
+
+static int hammer_register_leds(struct hid_device *hdev)
+{
+       struct hammer_kbd_leds *kbd_backlight;
+
+       kbd_backlight = devm_kzalloc(&hdev->dev,
+                                    sizeof(*kbd_backlight),
+                                    GFP_KERNEL);
+       if (!kbd_backlight)
+               return -ENOMEM;
+
+       kbd_backlight->hdev = hdev;
+       kbd_backlight->cdev.name = "hammer::kbd_backlight";
+       kbd_backlight->cdev.max_brightness = MAX_BRIGHTNESS;
+       kbd_backlight->cdev.brightness_set_blocking =
+               hammer_kbd_brightness_set_blocking;
+       kbd_backlight->cdev.flags = LED_HW_PLUGGABLE;
+
+       /* Set backlight to 0% initially. */
+       hammer_kbd_brightness_set_blocking(&kbd_backlight->cdev, 0);
+
+       return devm_led_classdev_register(&hdev->dev, &kbd_backlight->cdev);
+}
+
+static int hammer_input_configured(struct hid_device *hdev,
+                                  struct hid_input *hi)
+{
+       struct list_head *report_list =
+               &hdev->report_enum[HID_OUTPUT_REPORT].report_list;
+       struct hid_report *report;
+
+       if (list_empty(report_list))
+               return 0;
+
+       report = list_first_entry(report_list, struct hid_report, list);
+
+       if (report->maxfield == 1 &&
+           report->field[0]->application == HID_GD_KEYBOARD &&
+           report->field[0]->maxusage == 1 &&
+           report->field[0]->usage[0].hid == HID_AD_BRIGHTNESS) {
+               int err = hammer_register_leds(hdev);
+
+               if (err)
+                       hid_warn(hdev,
+                               "Failed to register keyboard backlight: %d\n",
+                               err);
+       }
+
+       return 0;
+}
+
+static const struct hid_device_id hammer_devices[] = {
+       { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
+                    USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_HAMMER) },
+       { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
+                    USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STAFF) },
+       { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
+                    USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_WAND) },
+       { }
+};
+MODULE_DEVICE_TABLE(hid, hammer_devices);
+
+static struct hid_driver hammer_driver = {
+       .name = "hammer",
+       .id_table = hammer_devices,
+       .input_configured = hammer_input_configured,
+};
+module_hid_driver(hammer_driver);
+
+MODULE_LICENSE("GPL");

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 43ddcdfbd0da415b4fc397a89582290f3f37c786..360c2893bb2d0e0b6a42f23213510654dd600e91 100644 (file)
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -445,7 +445,10 @@
 #define USB_DEVICE_ID_GOODTOUCH_000f   0x000f
 
 #define USB_VENDOR_ID_GOOGLE           0x18d1
+#define USB_DEVICE_ID_GOOGLE_HAMMER    0x5022
 #define USB_DEVICE_ID_GOOGLE_TOUCH_ROSE        0x5028
+#define USB_DEVICE_ID_GOOGLE_STAFF     0x502b
+#define USB_DEVICE_ID_GOOGLE_WAND      0x502d
 
 #define USB_VENDOR_ID_GOTOP            0x08f2
 #define USB_DEVICE_ID_SUPER_Q2         0x007f