[PATCH 2/4] HID: hid-msi-claw: Add M-key mapping attributes

["Derek J. Clark" <derekjohn.clark@gmail.com>]

Adds attributes that allow for remapping the M-keys with up to 5 values
when in macro mode. There are 2 mappable buttons on the rear of the
device, M1 on the right and M2 on the left. When mapped, the events will
fire from one of three event devices: gamepad buttons will fire from the
device handled by xpad, while keyboard and mouse events will fire from
respectively typed evdevs provided by the input core. Names of each
mapping have been kept as close to the event that will fire from the evdev
as possible, with context added to the ABS_ events on the direction of the
movement.

Initial reverse-engineering and implementation of this feature was done
by Zhouwang Huang. I refactored the overall format to conform to kernel
driver best practices and style guides. Claude was used as an initial
reviewer of this patch.

Assisted-by: Claude:claude-sonnet-4-6
Co-developed-by: Zhouwang Huang <honjow311@gmail.com>
Signed-off-by: Zhouwang Huang <honjow311@gmail.com>
Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
---
 drivers/hid/hid-msi-claw.c | 390 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 389 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-msi-claw.c b/drivers/hid/hid-msi-claw.c
index 7a3cd940ec49..60694d075d56 100644
--- a/drivers/hid/hid-msi-claw.c
+++ b/drivers/hid/hid-msi-claw.c
@@ -40,6 +40,8 @@
 #define CLAW_DINPUT_CFG_INTF_IN	0x82
 #define CLAW_XINPUT_CFG_INTF_IN	0x83
 
+#define CLAW_KEYS_MAX		5
+
 enum claw_command_index {
 	CLAW_COMMAND_TYPE_READ_PROFILE =		0x04,
 	CLAW_COMMAND_TYPE_READ_PROFILE_ACK =		0x05,
@@ -64,6 +66,17 @@ static const char * const claw_gamepad_mode_text[] = {
 	[CLAW_GAMEPAD_MODE_DESKTOP] =	"desktop",
 };
 
+enum claw_profile_ack_pending {
+	CLAW_NO_PENDING,
+	CLAW_M1_PENDING,
+	CLAW_M2_PENDING,
+};
+
+enum claw_key_index {
+	CLAW_KEY_M1,
+	CLAW_KEY_M2,
+};
+
 enum claw_mkeys_function_index {
 	CLAW_MKEY_FUNCTION_MACRO,
 	CLAW_MKEY_FUNCTION_COMBO,
@@ -76,6 +89,154 @@ static const char * const claw_mkeys_function_text[] = {
 	[CLAW_MKEY_FUNCTION_DISABLED] =	"disabled",
 };
 
+static const struct {
+	u8 code;
+	const char *name;
+} claw_button_mapping_key_map[] = {
+	/* Gamepad buttons */
+	{ 0x01, "ABS_HAT0Y_UP" },
+	{ 0x02, "ABS_HAT0Y_DOWN" },
+	{ 0x03, "ABS_HAT0X_LEFT" },
+	{ 0x04, "ABS_HAT0X_RIGHT" },
+	{ 0x05, "BTN_TL" },
+	{ 0x06, "BTN_TR" },
+	{ 0x07, "BTN_THUMBL" },
+	{ 0x08, "BTN_THUMBR" },
+	{ 0x09, "BTN_SOUTH" },
+	{ 0x0a, "BTN_EAST" },
+	{ 0x0b, "BTN_NORTH" },
+	{ 0x0c, "BTN_WEST" },
+	{ 0x0d, "BTN_MODE" },
+	{ 0x0e, "BTN_SELECT" },
+	{ 0x0f, "BTN_START" },
+	{ 0x13, "BTN_TL2"},
+	{ 0x14, "BTN_TR2"},
+	{ 0x15, "ABS_Y_UP"},
+	{ 0x16, "ABS_Y_DOWN"},
+	{ 0x17, "ABS_X_LEFT"},
+	{ 0x18, "ABS_X_LEFT_RIGHT"},
+	{ 0x19, "ABS_RY_UP"},
+	{ 0x1a, "ABS_RY_DOWN"},
+	{ 0x1b, "ABS_RX_LEFT"},
+	{ 0x1c, "ABS_RX_RIGHT"},
+	/* Keyboard keys */
+	{ 0x32, "KEY_ESC" },
+	{ 0x33, "KEY_F1" },
+	{ 0x34, "KEY_F2" },
+	{ 0x35, "KEY_F3" },
+	{ 0x36, "KEY_F4" },
+	{ 0x37, "KEY_F5" },
+	{ 0x38, "KEY_F6" },
+	{ 0x39, "KEY_F7" },
+	{ 0x3a, "KEY_F8" },
+	{ 0x3b, "KEY_F9" },
+	{ 0x3c, "KEY_F10" },
+	{ 0x3d, "KEY_F11" },
+	{ 0x3e, "KEY_F12" },
+	{ 0x3f, "KEY_GRAVE" },
+	{ 0x40, "KEY_1" },
+	{ 0x41, "KEY_2" },
+	{ 0x42, "KEY_3" },
+	{ 0x43, "KEY_4" },
+	{ 0x44, "KEY_5" },
+	{ 0x45, "KEY_6" },
+	{ 0x46, "KEY_7" },
+	{ 0x47, "KEY_8" },
+	{ 0x48, "KEY_9" },
+	{ 0x49, "KEY_0" },
+	{ 0x4a, "KEY_MINUS" },
+	{ 0x4b, "KEY_EQUAL" },
+	{ 0x4c, "KEY_BACKSPACE" },
+	{ 0x4d, "KEY_TAB" },
+	{ 0x4e, "KEY_Q" },
+	{ 0x4f, "KEY_W" },
+	{ 0x50, "KEY_E" },
+	{ 0x51, "KEY_R" },
+	{ 0x52, "KEY_T" },
+	{ 0x53, "KEY_Y" },
+	{ 0x54, "KEY_U" },
+	{ 0x55, "KEY_I" },
+	{ 0x56, "KEY_O" },
+	{ 0x57, "KEY_P" },
+	{ 0x58, "KEY_LEFTBRACE" },
+	{ 0x59, "KEY_RIGHTBRACE" },
+	{ 0x5a, "KEY_BACKSLASH" },
+	{ 0x5b, "KEY_CAPSLOCK" },
+	{ 0x5c, "KEY_A" },
+	{ 0x5d, "KEY_S" },
+	{ 0x5e, "KEY_D" },
+	{ 0x5f, "KEY_F" },
+	{ 0x60, "KEY_G" },
+	{ 0x61, "KEY_H" },
+	{ 0x62, "KEY_J" },
+	{ 0x63, "KEY_K" },
+	{ 0x64, "KEY_L" },
+	{ 0x65, "KEY_SEMICOLON" },
+	{ 0x66, "KEY_APOSTROPHE" },
+	{ 0x67, "KEY_ENTER" },
+	{ 0x68, "KEY_LEFTSHIFT" },
+	{ 0x69, "KEY_Z" },
+	{ 0x6a, "KEY_X" },
+	{ 0x6b, "KEY_C" },
+	{ 0x6c, "KEY_V" },
+	{ 0x6d, "KEY_B" },
+	{ 0x6e, "KEY_N" },
+	{ 0x6f, "KEY_M" },
+	{ 0x70, "KEY_COMMA" },
+	{ 0x71, "KEY_DOT" },
+	{ 0x72, "KEY_SLASH" },
+	{ 0x73, "KEY_RIGHTSHIFT" },
+	{ 0x74, "KEY_LEFTCTRL" },
+	{ 0x75, "KEY_LEFTMETA" },
+	{ 0x76, "KEY_LEFTALT" },
+	{ 0x77, "KEY_SPACE" },
+	{ 0x78, "KEY_RIGHTALT" },
+	{ 0x79, "KEY_RIGHTCTRL" },
+	{ 0x7a, "KEY_INSERT" },
+	{ 0x7b, "KEY_HOME" },
+	{ 0x7c, "KEY_PAGEUP" },
+	{ 0x7d, "KEY_DELETE" },
+	{ 0x7e, "KEY_END" },
+	{ 0x7f, "KEY_PAGEDOWN" },
+	{ 0x8a, "KEY_KPENTER" },
+	{ 0x8b, "KEY_KP0" },
+	{ 0x8c, "KEY_KP1" },
+	{ 0x8d, "KEY_KP2" },
+	{ 0x8e, "KEY_KP3" },
+	{ 0x8f, "KEY_KP4" },
+	{ 0x90, "KEY_KP5" },
+	{ 0x91, "KEY_KP6" },
+	{ 0x92, "KEY_KP7" },
+	{ 0x93, "KEY_KP8" },
+	{ 0x94, "KEY_KP9" },
+	{ 0x95, "MD_PLAY" },
+	{ 0x96, "MD_STOP" },
+	{ 0x97, "MD_NEXT" },
+	{ 0x98, "MD_PREV" },
+	{ 0x99, "MD_VOL_UP" },
+	{ 0x9a, "MD_VOL_DOWN" },
+	{ 0x9b, "MD_VOL_MUTE" },
+	{ 0x9c, "KEY_F23" },
+	/* Mouse events */
+	{ 0xc8, "BTN_LEFT" },
+	{ 0xc9, "BTN_MIDDLE" },
+	{ 0xca, "BTN_RIGHT" },
+	{ 0xcb, "BTN_SIDE" },
+	{ 0xcc, "BTN_EXTRA" },
+	{ 0xcd, "REL_WHEEL_UP" },
+	{ 0xce, "REL_WHEEL_DOWN" },
+};
+
+static const u16 button_mapping_addr_old[] = {
+	0x007a,  /* M1 */
+	0x011f,  /* M2 */
+};
+
+static const u16 button_mapping_addr_new[] = {
+	0x00bb,  /* M1 */
+	0x0164,  /* M2 */
+};
+
 struct claw_command_report {
 	u8 report_id;
 	u8 padding[2];
@@ -86,16 +247,22 @@ struct claw_command_report {
 
 struct claw_drvdata {
 	/* MCU General Variables */
+	enum claw_profile_ack_pending profile_pending;
 	struct completion send_cmd_complete;
 	struct delayed_work cfg_resume;
 	struct delayed_work cfg_setup;
 	struct hid_device *hdev;
 	struct mutex cfg_mutex; /* mutex for synchronous data */
+	u16 bcd_device;
 	int endpoint;
 
 	/* Gamepad Variables */
 	enum claw_mkeys_function_index mkeys_function;
 	enum claw_gamepad_mode_index gamepad_mode;
+	u8 m1_codes[CLAW_KEYS_MAX];
+	u8 m2_codes[CLAW_KEYS_MAX];
+	const u16 *bmap_addr;
+	bool bmap_support;
 };
 
 static int get_endpoint_address(struct hid_device *hdev)
@@ -123,6 +290,31 @@ static int claw_gamepad_mode_event(struct claw_drvdata *drvdata,
 	return 0;
 }
 
+static int claw_profile_event(struct claw_drvdata *drvdata, struct claw_command_report *cmd_rep)
+{
+	u8 *codes;
+	int i;
+
+	switch (drvdata->profile_pending) {
+	case CLAW_M1_PENDING:
+	case CLAW_M2_PENDING:
+		codes = (drvdata->profile_pending == CLAW_M1_PENDING) ?
+			drvdata->m1_codes : drvdata->m2_codes;
+		/* Extract key codes; replace disabled (0xff) with 0x00, which is (null) in _show */
+		for (i = 0; i < CLAW_KEYS_MAX; i++)
+			codes[i] = (cmd_rep->data[6 + i] != 0xff) ? cmd_rep->data[6 + i] : 0x00;
+		break;
+	default:
+		dev_warn(&drvdata->hdev->dev,
+			 "Got profile event without changes pending from command:%x\n",
+			 cmd_rep->cmd);
+		return -EINVAL;
+	}
+	drvdata->profile_pending = CLAW_NO_PENDING;
+
+	return 0;
+}
+
 static int claw_raw_event(struct hid_device *hdev, struct hid_report *report,
 			  u8 *data, int size)
 {
@@ -149,6 +341,9 @@ static int claw_raw_event(struct hid_device *hdev, struct hid_report *report,
 	case CLAW_COMMAND_TYPE_GAMEPAD_MODE_ACK:
 		ret = claw_gamepad_mode_event(drvdata, cmd_rep);
 		break;
+	case CLAW_COMMAND_TYPE_READ_PROFILE_ACK:
+		ret = claw_profile_event(drvdata, cmd_rep);
+		break;
 	case CLAW_COMMAND_TYPE_ACK:
 		break;
 	default:
@@ -356,6 +551,157 @@ static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_WO(reset);
 
+static int button_mapping_name_to_code(const char *name)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(claw_button_mapping_key_map); i++) {
+		if (!strcmp(name, claw_button_mapping_key_map[i].name))
+			return claw_button_mapping_key_map[i].code;
+	}
+
+	return -EINVAL;
+}
+
+static const char *button_mapping_code_to_name(u8 code)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(claw_button_mapping_key_map); i++) {
+		if (claw_button_mapping_key_map[i].code == code)
+			return claw_button_mapping_key_map[i].name;
+	}
+
+	return NULL;
+}
+
+static int claw_buttons_store(struct device *dev, const char *buf, u8 mkey_idx)
+{
+	struct hid_device *hdev = to_hid_device(dev);
+	struct claw_drvdata *drvdata = hid_get_drvdata(hdev);
+	u8 data[] = { 0x01, (drvdata->bmap_addr[mkey_idx] >> 8) & 0xff,
+		      drvdata->bmap_addr[mkey_idx] & 0xff, 0x07,
+		      0x04, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff };
+	size_t len = ARRAY_SIZE(data);
+	int ret, key_count, i;
+	char **raw_keys;
+
+	raw_keys = argv_split(GFP_KERNEL, buf, &key_count);
+	if (!raw_keys)
+		return -ENOMEM;
+
+	if (key_count > CLAW_KEYS_MAX) {
+		ret = -EINVAL;
+		goto err_free;
+	}
+
+	if (key_count == 0)
+		goto set_buttons;
+
+	for (i = 0; i < key_count; i++) {
+		ret = button_mapping_name_to_code(raw_keys[i]);
+		if (ret < 0)
+			goto err_free;
+
+		data[6 + i] = ret;
+	}
+
+set_buttons:
+	ret = mcu_property_out(hdev, CLAW_COMMAND_TYPE_WRITE_PROFILE_DATA, data, len, 8);
+	if (ret < 0)
+		goto err_free;
+
+	ret = mcu_property_out(hdev, CLAW_COMMAND_TYPE_SYNC_TO_ROM, NULL, 0, 0);
+
+err_free:
+	argv_free(raw_keys);
+	return ret;
+}
+
+static int claw_buttons_show(struct device *dev, char *buf, enum claw_key_index m_key)
+{
+	struct hid_device *hdev = to_hid_device(dev);
+	struct claw_drvdata *drvdata = hid_get_drvdata(hdev);
+	u8 data[] = { 0x01, (drvdata->bmap_addr[m_key] >> 8) & 0xff,
+		      drvdata->bmap_addr[m_key] & 0xff, 0x07 };
+	size_t len = ARRAY_SIZE(data);
+	int i, ret, count = 0;
+	const char *name;
+	u8 *codes;
+
+	codes = (m_key == CLAW_KEY_M1) ? drvdata->m1_codes : drvdata->m2_codes;
+	drvdata->profile_pending = (m_key == CLAW_KEY_M1) ? CLAW_M1_PENDING : CLAW_M2_PENDING;
+
+	ret = mcu_property_out(hdev, CLAW_COMMAND_TYPE_READ_PROFILE, data, len, 8);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < CLAW_KEYS_MAX; i++) {
+		name = button_mapping_code_to_name(codes[i]);
+		if (name)
+			count += sysfs_emit_at(buf, count, "%s ", name);
+	}
+
+	if (!count)
+		return sysfs_emit(buf, "(not set)\n");
+
+	buf[count - 1] = '\n';
+
+	return count;
+}
+
+static ssize_t button_m1_store(struct device *dev, struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	int ret;
+
+	ret = claw_buttons_store(dev, buf, CLAW_KEY_M1);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t button_m1_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	return claw_buttons_show(dev, buf, CLAW_KEY_M1);
+}
+static DEVICE_ATTR_RW(button_m1);
+
+static ssize_t button_m2_store(struct device *dev, struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	int ret;
+
+	ret = claw_buttons_store(dev, buf, CLAW_KEY_M2);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t button_m2_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	return claw_buttons_show(dev, buf, CLAW_KEY_M2);
+}
+static DEVICE_ATTR_RW(button_m2);
+
+static ssize_t button_mapping_options_show(struct device *dev,
+					   struct device_attribute *attr, char *buf)
+{
+	int i, count = 0;
+
+	for (i = 0; i < ARRAY_SIZE(claw_button_mapping_key_map); i++)
+		count += sysfs_emit_at(buf, count, "%s ", claw_button_mapping_key_map[i].name);
+
+	buf[count - 1] = '\n';
+
+	return count;
+}
+static DEVICE_ATTR_RO(button_mapping_options);
+
 static umode_t claw_gamepad_attr_is_visible(struct kobject *kobj, struct attribute *attr,
 					    int n)
 {
@@ -368,10 +714,22 @@ static umode_t claw_gamepad_attr_is_visible(struct kobject *kobj, struct attribu
 		return 0;
 	}
 
-	return attr->mode;
+	/* Always show attrs available on all firmware */
+	if (attr == &dev_attr_gamepad_mode.attr ||
+	    attr == &dev_attr_gamepad_mode_index.attr ||
+	    attr == &dev_attr_mkeys_function.attr ||
+	    attr == &dev_attr_mkeys_function_index.attr ||
+	    attr == &dev_attr_reset.attr)
+		return attr->mode;
+
+	/* Hide button mapping attrs if it isn't supported */
+	return drvdata->bmap_support ? attr->mode : 0;
 }
 
 static struct attribute *claw_gamepad_attrs[] = {
+	&dev_attr_button_m1.attr,
+	&dev_attr_button_m2.attr,
+	&dev_attr_button_mapping_options.attr,
 	&dev_attr_gamepad_mode.attr,
 	&dev_attr_gamepad_mode_index.attr,
 	&dev_attr_mkeys_function.attr,
@@ -424,6 +782,29 @@ static void cfg_resume_fn(struct work_struct *work)
 		dev_err(&drvdata->hdev->dev, "Failed to set gamepad mode settings: %d\n", ret);
 }
 
+static void claw_features_supported(struct claw_drvdata *drvdata)
+{
+	u8 major = (drvdata->bcd_device >> 8) & 0xff;
+	u8 minor = drvdata->bcd_device & 0xff;
+
+	if (major == 0x01) {
+		drvdata->bmap_support = true;
+		if (minor >= 0x66)
+			drvdata->bmap_addr = button_mapping_addr_new;
+		else
+			drvdata->bmap_addr = button_mapping_addr_old;
+		return;
+	}
+
+	if ((major == 0x02 && minor >= 0x17) || major >= 0x03) {
+		drvdata->bmap_support = true;
+		drvdata->bmap_addr = button_mapping_addr_new;
+		return;
+	}
+
+	drvdata->bmap_support = false;
+}
+
 static int claw_probe(struct hid_device *hdev, const struct hid_device_id *id)
 {
 	struct claw_drvdata *drvdata;
@@ -470,6 +851,13 @@ static int claw_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	if (ret)
 		goto err_stop_hw;
 
+	/* Determine feature level from firmware version */
+	drvdata->bcd_device = le16_to_cpu(udev->descriptor.bcdDevice);
+	claw_features_supported(drvdata);
+
+	if (!drvdata->bmap_support)
+		dev_warn(&hdev->dev, "M-Key mapping is not supported. Update firmware to enable.\n");
+
 	init_completion(&drvdata->send_cmd_complete);
 
 	INIT_DELAYED_WORK(&drvdata->cfg_resume, &cfg_resume_fn);
-- 
2.53.0