[PATCH v4] HID: cmedia: add support for HS-100B mute button

From: Thomas Weißschuh
Date: Tue Jul 20 2021 - 16:45:57 EST


These chips report mute button events in bit 4 of their report without it
being part of the report descriptor.
Use a custom descriptor that maps this bit.

Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---

v1: https://lore.kernel.org/linux-input/a769ae40-6d0c-47c4-803f-2c8dbc362f24@xxxxxxxx/

v1 -> v2:
* Merged into the existing cmedia driver instead of creating a dedicated
driver.

v2: https://lore.kernel.org/linux-input/20210716160659.154779-1-linux@xxxxxxxxxxxxxx/

v2 -> v3:
* Fixed cosmetic checkpatch warnings
* CC-ed Ben Chen who is the original author of hid-cmedia.c

v3: https://lore.kernel.org/linux-input/20210719110911.310701-1-linux@xxxxxxxxxxxxxx/

v3 -> v4:
* Create a dedicated struct hid_driver, leaving the existing intact
* Drop entry in hid-quirks.c

drivers/hid/Kconfig | 5 ++-
drivers/hid/hid-cmedia.c | 90 +++++++++++++++++++++++++++++++++++++++-
drivers/hid/hid-ids.h | 1 +
3 files changed, 92 insertions(+), 4 deletions(-)

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 160554903ef9..6f72ecd79db0 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -259,10 +259,11 @@ config HID_PRODIKEYS
and some additional multimedia keys.

config HID_CMEDIA
- tristate "CMedia CM6533 HID audio jack controls"
+ tristate "CMedia audio chips"
depends on HID
help
- Support for CMedia CM6533 HID audio jack controls.
+ Support for CMedia CM6533 HID audio jack controls
+ and HS100B mute buttons.

config HID_CP2112
tristate "Silicon Labs CP2112 HID USB-to-SMBus Bridge support"
diff --git a/drivers/hid/hid-cmedia.c b/drivers/hid/hid-cmedia.c
index 3296c5050264..cab42047bc99 100644
--- a/drivers/hid/hid-cmedia.c
+++ b/drivers/hid/hid-cmedia.c
@@ -1,8 +1,10 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* HID driver for CMedia CM6533 audio jack controls
+ * and HS100B mute buttons
*
* Copyright (C) 2015 Ben Chen <ben_chen@xxxxxxxxxxxxxxx>
+ * Copyright (C) 2021 Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
*/

#include <linux/device.h>
@@ -11,13 +13,53 @@
#include "hid-ids.h"

MODULE_AUTHOR("Ben Chen");
-MODULE_DESCRIPTION("CM6533 HID jack controls");
+MODULE_AUTHOR("Thomas Weißschuh");
+MODULE_DESCRIPTION("CM6533 HID jack controls and HS100B mute button");
MODULE_LICENSE("GPL");

#define CM6533_JD_TYPE_COUNT 1
#define CM6533_JD_RAWEV_LEN 16
#define CM6533_JD_SFX_OFFSET 8

+#define HS100B_RDESC_ORIG_SIZE 60
+
+/* Fixed report descriptor of HS-100B audio chip
+ * Bit 4 is an abolute Microphone mute usage instead of being unassigned.
+ */
+static __u8 hs100b_rdesc_fixed[] = {
+ 0x05, 0x0C, /* Usage Page (Consumer), */
+ 0x09, 0x01, /* Usage (Consumer Control), */
+ 0xA1, 0x01, /* Collection (Application), */
+ 0x15, 0x00, /* Logical Minimum (0), */
+ 0x25, 0x01, /* Logical Maximum (1), */
+ 0x09, 0xE9, /* Usage (Volume Inc), */
+ 0x09, 0xEA, /* Usage (Volume Dec), */
+ 0x75, 0x01, /* Report Size (1), */
+ 0x95, 0x02, /* Report Count (2), */
+ 0x81, 0x02, /* Input (Variable), */
+ 0x09, 0xE2, /* Usage (Mute), */
+ 0x95, 0x01, /* Report Count (1), */
+ 0x81, 0x06, /* Input (Variable, Relative), */
+ 0x05, 0x0B, /* Usage Page (Telephony), */
+ 0x09, 0x2F, /* Usage (2Fh), */
+ 0x81, 0x02, /* Input (Variable), */
+ 0x09, 0x20, /* Usage (20h), */
+ 0x81, 0x06, /* Input (Variable, Relative), */
+ 0x05, 0x0C, /* Usage Page (Consumer), */
+ 0x09, 0x00, /* Usage (00h), */
+ 0x95, 0x03, /* Report Count (3), */
+ 0x81, 0x02, /* Input (Variable), */
+ 0x26, 0xFF, 0x00, /* Logical Maximum (255), */
+ 0x09, 0x00, /* Usage (00h), */
+ 0x75, 0x08, /* Report Size (8), */
+ 0x95, 0x03, /* Report Count (3), */
+ 0x81, 0x02, /* Input (Variable), */
+ 0x09, 0x00, /* Usage (00h), */
+ 0x95, 0x04, /* Report Count (4), */
+ 0x91, 0x02, /* Output (Variable), */
+ 0xC0 /* End Collection */
+};
+
/*
*
*CM6533 audio jack HID raw events:
@@ -156,5 +198,49 @@ static struct hid_driver cmhid_driver = {
.remove = cmhid_remove,
.input_mapping = cmhid_input_mapping,
};
-module_hid_driver(cmhid_driver);

+static __u8 *cmhid_hs100b_report_fixup(struct hid_device *hid, __u8 *rdesc,
+ unsigned int *rsize)
+{
+ if (*rsize == HS100B_RDESC_ORIG_SIZE) {
+ hid_info(hid, "Fixing CMedia HS-100B report descriptor\n");
+ rdesc = hs100b_rdesc_fixed;
+ *rsize = sizeof(hs100b_rdesc_fixed);
+ }
+ return rdesc;
+}
+
+static const struct hid_device_id cmhid_hs100b_devices[] = {
+ { HID_USB_DEVICE(USB_VENDOR_ID_CMEDIA, USB_DEVICE_ID_CMEDIA_HS100B) },
+ { }
+};
+MODULE_DEVICE_TABLE(hid, cmhid_hs100b_devices);
+
+static struct hid_driver cmhid_hs100b_driver = {
+ .name = "cmedia_hs100b",
+ .id_table = cmhid_hs100b_devices,
+ .report_fixup = cmhid_hs100b_report_fixup,
+};
+
+static int cmedia_init(void)
+{
+ int ret;
+
+ ret = hid_register_driver(&cmhid_driver);
+ if (ret)
+ return ret;
+
+ ret = hid_register_driver(&cmhid_hs100b_driver);
+ if (ret)
+ hid_unregister_driver(&cmhid_driver);
+
+ return ret;
+}
+module_init(cmedia_init);
+
+static void cmedia_exit(void)
+{
+ hid_unregister_driver(&cmhid_driver);
+ hid_unregister_driver(&cmhid_hs100b_driver);
+}
+module_exit(cmedia_exit);
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 8f1893e68112..6864e4e6ac8b 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -292,6 +292,7 @@

#define USB_VENDOR_ID_CMEDIA 0x0d8c
#define USB_DEVICE_ID_CM109 0x000e
+#define USB_DEVICE_ID_CMEDIA_HS100B 0x0014
#define USB_DEVICE_ID_CM6533 0x0022

#define USB_VENDOR_ID_CODEMERCS 0x07c0

base-commit: 1b97ec646386cea5b4be139f7685b4a4b4d3799a
--
2.32.0