From bc179b1030ccf9dd02818f77ecd9b5b9f14e85b7 Mon Sep 17 00:00:00 2001
From: Peter Johanson <peter@peterjohanson.com>
Date: Tue, 5 Oct 2021 02:41:56 +0000
Subject: [PATCH] feat(hid): Kconfig for basic/full consumer usages.

* Add ZMK_HID_CONSUMER_REPORT_USAGES choice to allow choosing
  between full consumer usage range, with poor OS compat,
  or basic consumer usage range, with broader compat.
---
 app/Kconfig           | 19 ++++++++++++++++++-
 app/include/zmk/hid.h | 25 +++++++++++++++++++++++++
 app/src/hid.c         |  2 ++
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/app/Kconfig b/app/Kconfig
index 629dfa70..35bf77da 100644
--- a/app/Kconfig
+++ b/app/Kconfig
@@ -51,13 +51,30 @@ config ZMK_HID_KEYBOARD_REPORT_SIZE
 	int "# Keyboard Keys Reportable"
 	default 6
 
-
 endif
 
 config ZMK_HID_CONSUMER_REPORT_SIZE
 	int "# Consumer Keys Reportable"
 	default 6
 
+
+choice ZMK_HID_CONSUMER_REPORT_USAGES
+	prompt "HID Report Type"
+
+config ZMK_HID_CONSUMER_REPORT_USAGES_FULL
+	bool "Full Consumer HID Usage Support"
+	help
+	  Enable full Consumer usage ID values to be sent to hosts. Allows for less
+	  frequently used usages, but has compatibability issues with some host OSes.
+
+config ZMK_HID_CONSUMER_REPORT_USAGES_BASIC
+	bool "Basic Consumer HID Usage Support"
+	help
+	  Enable Consumer usage ID values up to "Playback Speed - Slow" to be sent to
+	  hosts. Allows for broader compatibability with more host OSes.
+
+endchoice
+
 menu "Output Types"
 
 config ZMK_USB
diff --git a/app/include/zmk/hid.h b/app/include/zmk/hid.h
index be88c175..95b82d46 100644
--- a/app/include/zmk/hid.h
+++ b/app/include/zmk/hid.h
@@ -138,6 +138,24 @@ static const uint8_t zmk_hid_report_desc[] = {
     /* USAGE_PAGE (Consumer) */
     HID_GI_USAGE_PAGE,
     HID_USAGE_CONSUMER,
+
+#if IS_ENABLED(CONFIG_ZMK_HID_CONSUMER_REPORT_USAGES_BASIC)
+    /* LOGICAL_MINIMUM (0) */
+    HID_GI_LOGICAL_MIN(1),
+    0x00,
+    /* LOGICAL_MAXIMUM (0xFFFF) */
+    HID_GI_LOGICAL_MAX(1),
+    0xFF,
+    HID_LI_USAGE_MIN(1),
+    0x00,
+    /* USAGE_MAXIMUM (0xFFFF) */
+    HID_LI_USAGE_MAX(1),
+    0xFF,
+    /* INPUT (Data,Ary,Abs) */
+    /* REPORT_SIZE (8) */
+    HID_GI_REPORT_SIZE,
+    0x08,
+#elif IS_ENABLED(CONFIG_ZMK_HID_CONSUMER_REPORT_USAGES_FULL)
     /* LOGICAL_MINIMUM (0) */
     HID_GI_LOGICAL_MIN(1),
     0x00,
@@ -155,6 +173,9 @@ static const uint8_t zmk_hid_report_desc[] = {
     /* REPORT_SIZE (16) */
     HID_GI_REPORT_SIZE,
     0x10,
+#else
+#error "A proper consumer HID report usage range must be selected"
+#endif
     /* REPORT_COUNT (CONFIG_ZMK_HID_CONSUMER_REPORT_SIZE) */
     HID_GI_REPORT_COUNT,
     CONFIG_ZMK_HID_CONSUMER_REPORT_SIZE,
@@ -187,7 +208,11 @@ struct zmk_hid_keyboard_report {
 } __packed;
 
 struct zmk_hid_consumer_report_body {
+#if IS_ENABLED(CONFIG_ZMK_HID_CONSUMER_REPORT_USAGES_BASIC)
+    uint8_t keys[CONFIG_ZMK_HID_CONSUMER_REPORT_SIZE];
+#elif IS_ENABLED(CONFIG_ZMK_HID_CONSUMER_REPORT_USAGES_FULL)
     uint16_t keys[CONFIG_ZMK_HID_CONSUMER_REPORT_SIZE];
+#endif
 } __packed;
 
 struct zmk_hid_consumer_report {
diff --git a/app/src/hid.c b/app/src/hid.c
index 756ed900..b524b09f 100644
--- a/app/src/hid.c
+++ b/app/src/hid.c
@@ -117,6 +117,8 @@ static inline int deselect_keyboard_usage(zmk_key_t usage) {
 #endif
 
 #define TOGGLE_CONSUMER(match, val)                                                                \
+    COND_CODE_1(IS_ENABLED(CONFIG_ZMK_HID_CONSUMER_REPORT_USAGES_BASIC),                           \
+                (if (val > 0xFF) { return -ENOTSUP; }), ())                                        \
     for (int idx = 0; idx < CONFIG_ZMK_HID_CONSUMER_REPORT_SIZE; idx++) {                          \
         if (consumer_report.body.keys[idx] != match) {                                             \
             continue;                                                                              \