Re: [PATCH v11 11/18] HID: asus: add support for btn remapping

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Sun, 25 Oct 2026, Denis Benato wrote:

> Add support for buttons remapping: the ability to assign different
> button events to each one of the physical button on the device.
> 
> Each button exposes a remap_index sysfs attribute listing the valid
> remap target names for the current gamepad mode: M1 and M2 can be
> remapped to anything at any time, while other buttons may only be
> remapped to gamepad codes in gamepad mode and keyboard/mouse/media
> codes in desktop mode.
> 
> When the gamepad mode is changed the firmware automatically restores
> its internal defaults, so the software cache is refreshed to reflect
> the hardware state.
> 
> Signed-off-by: Luke Jones <luke@ljones.dev>
> Signed-off-by: Denis Benato <denis.benato@linux.dev>
> Signed-off-by: Jonathan LoBue <jlobue10@gmail.com>
> ---
>  drivers/hid/hid-asus.c | 1059 +++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 1037 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> index ed95b2cdec81..ea27495c3df6 100644
> --- a/drivers/hid/hid-asus.c
> +++ b/drivers/hid/hid-asus.c
> @@ -275,9 +275,25 @@ struct ally_turbo_config {
>  	struct ally_btn_turbo_params btn_m1;
>  };
>  
> +/* Button remap attribute structure */
> +struct button_remap_attr {
> +	struct device_attribute dev_attr;
> +	enum ally_button_id button_id;
> +	bool is_macro;
> +	/*
> +	 * The attributes are created while hid_asus_ally_probe() is still
> +	 * running, before asus_probe() publishes drvdata->rog_ally: carry
> +	 * the pointer like the turbo entries do, so the callbacks work
> +	 * from the moment the files exist.
> +	 */
> +	struct ally_handheld *ally;
> +};
> +
> +#define to_button_remap_attr(x) container_of(x, struct button_remap_attr, dev_attr)
> +
>  struct ally_btn_sysfs_entry {
>  	struct attribute_group group;
> -	struct attribute *attrs[5]; /* turbo_period + toggle_period + ranges + NULL */
> +	struct attribute *attrs[8]; /* turbo + ranges + remap + macro + remap_index + NULL */
>  	/*
>  	 * The entries are created while hid_asus_ally_probe() is still running,
>  	 * before asus_probe() publishes drvdata->rog_ally: carrying the shared
> @@ -289,6 +305,9 @@ struct ally_btn_sysfs_entry {
>  	enum ally_button_id btn;
>  	struct device_attribute attr_turbo_period;
>  	struct device_attribute attr_toggle_period;
> +	struct button_remap_attr *remap_attr;
> +	struct button_remap_attr *macro_attr;
> +	struct device_attribute attr_remap_index;
>  };
>  
>  enum ally_gamepad_mode_index {
> @@ -296,6 +315,35 @@ enum ally_gamepad_mode_index {
>  	ALLY_GAMEPAD_MODE_KEYBOARD = 0x02,
>  };
>  
> +/* Button pair indexes for mapping commands */
> +enum btn_pair_index {
> +	BTN_PAIR_DPAD_UPDOWN    = 0x01,
> +	BTN_PAIR_DPAD_LEFTRIGHT = 0x02,
> +	BTN_PAIR_STICK_LR       = 0x03,
> +	BTN_PAIR_BUMPER_LR      = 0x04,
> +	BTN_PAIR_AB             = 0x05,
> +	BTN_PAIR_XY             = 0x06,
> +	BTN_PAIR_VIEW_MENU      = 0x07,
> +	BTN_PAIR_M1M2           = 0x08,
> +	BTN_PAIR_TRIGGER_LR     = 0x09,
> +};
> +
> +struct button_map {
> +	const struct btn_code_map *remap;
> +	const struct btn_code_map *macro;
> +};
> +
> +struct button_pair_map {
> +	enum btn_pair_index pair_index;
> +	struct button_map first;
> +	struct button_map second;
> +};
> +
> +/* Store button mapping per gamepad mode */
> +struct ally_button_mapping {
> +	struct button_pair_map button_pairs[9]; /* 9 button pairs */
> +};
> +
>  struct ally_config {
>  	/* Must be locked if the data is being changed */
>  	struct mutex config_mutex;
> @@ -331,6 +379,8 @@ struct ally_config {
>  
>  	struct ally_turbo_config turbo;
>  	struct ally_btn_sysfs_entry *button_entries;
> +	/* Button mappings of the current gamepad mode */
> +	struct ally_button_mapping button_mappings;
>  
>  	struct ally_joystick_resp_curve left_curve;
>  	struct ally_joystick_resp_curve right_curve;
> @@ -1072,6 +1122,295 @@ static int ally_set_gamepad_mode(struct ally_handheld *ally, struct hid_device *
>  	return 0;
>  }
>  
> +enum btn_map_type {
> +	BTN_TYPE_NONE = 0,
> +	BTN_TYPE_PAD = 0x01,
> +	BTN_TYPE_KB = 0x02,
> +	BTN_TYPE_MOUSE = 0x03,
> +	BTN_TYPE_MEDIA = 0x05,
> +};
> +
> +struct btn_code_map {
> +	unsigned char type;
> +	unsigned char value;
> +	const char *name;
> +};
> +
> +static const struct btn_code_map ally_btn_codes[] = {
> +	{ BTN_TYPE_NONE, 0x00, "NONE" },
> +	/* Gamepad button codes */
> +	{ BTN_TYPE_PAD, 0x01, "BTN_SOUTH" },
> +	{ BTN_TYPE_PAD, 0x02, "BTN_EAST" },
> +	{ BTN_TYPE_PAD, 0x03, "BTN_NORTH" },
> +	{ BTN_TYPE_PAD, 0x04, "BTN_WEST" },
> +	{ BTN_TYPE_PAD, 0x05, "BTN_TL" },
> +	{ BTN_TYPE_PAD, 0x06, "BTN_TR" },
> +	{ BTN_TYPE_PAD, 0x07, "BTN_THUMBL" },
> +	{ BTN_TYPE_PAD, 0x08, "BTN_THUMBR" },
> +	{ BTN_TYPE_PAD, 0x09, "ABS_HAT0Y_NEG" },
> +	{ BTN_TYPE_PAD, 0x0A, "ABS_HAT0Y_POS" },
> +	{ BTN_TYPE_PAD, 0x0B, "ABS_HAT0X_NEG" },
> +	{ BTN_TYPE_PAD, 0x0C, "ABS_HAT0X_POS" },
> +	{ BTN_TYPE_PAD, 0x0D, "ABS_Z" },
> +	{ BTN_TYPE_PAD, 0x0E, "ABS_RZ" },
> +	{ BTN_TYPE_PAD, 0x11, "BTN_SELECT" },
> +	{ BTN_TYPE_PAD, 0x12, "BTN_START" },
> +	{ BTN_TYPE_PAD, 0x13, "BTN_MODE" },
> +
> +	/* Keyboard button codes */
> +	{ BTN_TYPE_KB, 0x8E, "FN_M2" },
> +	{ BTN_TYPE_KB, 0x8F, "FN_M1" },
> +	{ BTN_TYPE_KB, 0x76, "KEY_ESC" },
> +	{ BTN_TYPE_KB, 0x05, "KEY_F1" },
> +	{ BTN_TYPE_KB, 0x06, "KEY_F2" },
> +	{ BTN_TYPE_KB, 0x04, "KEY_F3" },
> +	{ BTN_TYPE_KB, 0x0C, "KEY_F4" },
> +	{ BTN_TYPE_KB, 0x03, "KEY_F5" },
> +	{ BTN_TYPE_KB, 0x0B, "KEY_F6" },
> +	{ BTN_TYPE_KB, 0x80, "KEY_F7" },
> +	{ BTN_TYPE_KB, 0x0A, "KEY_F8" },
> +	{ BTN_TYPE_KB, 0x01, "KEY_F9" },
> +	{ BTN_TYPE_KB, 0x09, "KEY_F10" },
> +	{ BTN_TYPE_KB, 0x78, "KEY_F11" },
> +	{ BTN_TYPE_KB, 0x07, "KEY_F12" },
> +	{ BTN_TYPE_KB, 0x08, "KEY_F13" },
> +	{ BTN_TYPE_KB, 0x10, "KEY_F14" },
> +	{ BTN_TYPE_KB, 0x18, "KEY_F15" },
> +	{ BTN_TYPE_KB, 0x0E, "KEY_GRAVE" }, // backtick
> +	{ BTN_TYPE_KB, 0x16, "KEY_1" },
> +	{ BTN_TYPE_KB, 0x1E, "KEY_2" },
> +	{ BTN_TYPE_KB, 0x26, "KEY_3" },
> +	{ BTN_TYPE_KB, 0x25, "KEY_4" },
> +	{ BTN_TYPE_KB, 0x2E, "KEY_5" },
> +	{ BTN_TYPE_KB, 0x36, "KEY_6" },
> +	{ BTN_TYPE_KB, 0x3D, "KEY_7" },
> +	{ BTN_TYPE_KB, 0x3E, "KEY_8" },
> +	{ BTN_TYPE_KB, 0x46, "KEY_9" },
> +	{ BTN_TYPE_KB, 0x45, "KEY_0" },
> +	{ BTN_TYPE_KB, 0x4E, "KEY_MINUS" }, // hyphen
> +	{ BTN_TYPE_KB, 0x55, "KEY_EQUAL" },
> +	{ BTN_TYPE_KB, 0x66, "KEY_BACKSPACE" },
> +	{ BTN_TYPE_KB, 0x0D, "KEY_TAB" },
> +	{ BTN_TYPE_KB, 0x15, "KEY_Q" },
> +	{ BTN_TYPE_KB, 0x1D, "KEY_W" },
> +	{ BTN_TYPE_KB, 0x24, "KEY_E" },
> +	{ BTN_TYPE_KB, 0x2D, "KEY_R" },
> +	{ BTN_TYPE_KB, 0x2C, "KEY_T" },
> +	{ BTN_TYPE_KB, 0x35, "KEY_Y" },
> +	{ BTN_TYPE_KB, 0x3C, "KEY_U" },
> +	{ BTN_TYPE_KB, 0x43, "KEY_I" },
> +	{ BTN_TYPE_KB, 0x44, "KEY_O" },
> +	{ BTN_TYPE_KB, 0x4D, "KEY_P" },
> +	{ BTN_TYPE_KB, 0x54, "KEY_LEFTBRACE" },
> +	{ BTN_TYPE_KB, 0x5B, "KEY_RIGHTBRACE" },
> +	{ BTN_TYPE_KB, 0x5D, "KEY_BACKSLASH" },
> +	{ BTN_TYPE_KB, 0x58, "KEY_CAPSLOCK" },
> +	{ BTN_TYPE_KB, 0x1C, "KEY_A" },
> +	{ BTN_TYPE_KB, 0x1B, "KEY_S" },
> +	{ BTN_TYPE_KB, 0x23, "KEY_D" },
> +	{ BTN_TYPE_KB, 0x2B, "KEY_F" },
> +	{ BTN_TYPE_KB, 0x34, "KEY_G" },
> +	{ BTN_TYPE_KB, 0x33, "KEY_H" },
> +	{ BTN_TYPE_KB, 0x3B, "KEY_J" },
> +	{ BTN_TYPE_KB, 0x42, "KEY_K" },
> +	{ BTN_TYPE_KB, 0x4B, "KEY_L" },
> +	{ BTN_TYPE_KB, 0x4C, "KEY_SEMICOLON" },
> +	{ BTN_TYPE_KB, 0x52, "KEY_APOSTROPHE" },
> +	{ BTN_TYPE_KB, 0x5A, "KEY_ENTER" },
> +	{ BTN_TYPE_KB, 0x88, "KEY_LEFTSHIFT" },
> +	{ BTN_TYPE_KB, 0x1A, "KEY_Z" },
> +	{ BTN_TYPE_KB, 0x22, "KEY_X" },
> +	{ BTN_TYPE_KB, 0x21, "KEY_C" },
> +	{ BTN_TYPE_KB, 0x2A, "KEY_V" },
> +	{ BTN_TYPE_KB, 0x32, "KEY_B" },
> +	{ BTN_TYPE_KB, 0x31, "KEY_N" },
> +	{ BTN_TYPE_KB, 0x3A, "KEY_M" },
> +	{ BTN_TYPE_KB, 0x41, "KEY_COMMA" },
> +	{ BTN_TYPE_KB, 0x49, "KEY_DOT" },
> +	{ BTN_TYPE_KB, 0x4A, "KEY_SLASH" },
> +	{ BTN_TYPE_KB, 0x89, "KEY_RIGHTSHIFT" },
> +	{ BTN_TYPE_KB, 0x82, "KEY_LEFTMETA" },
> +	{ BTN_TYPE_KB, 0x8A, "KEY_LEFTALT" },
> +	{ BTN_TYPE_KB, 0x29, "KEY_SPACE" },
> +	{ BTN_TYPE_KB, 0x8B, "KEY_RIGHTALT" },
> +	{ BTN_TYPE_KB, 0x84, "KEY_COMPOSE" },
> +	{ BTN_TYPE_KB, 0x8D, "KEY_RIGHTCTRL" },
> +	{ BTN_TYPE_KB, 0xC3, "KEY_SYSRQ" },
> +	{ BTN_TYPE_KB, 0x7E, "KEY_SCROLLLOCK" },
> +	{ BTN_TYPE_KB, 0x91, "KEY_PAUSE" },
> +	{ BTN_TYPE_KB, 0xC2, "KEY_INSERT" },
> +	{ BTN_TYPE_KB, 0x94, "KEY_HOME" },
> +	{ BTN_TYPE_KB, 0x96, "KEY_PAGEUP" },
> +	{ BTN_TYPE_KB, 0xC0, "KEY_DELETE" },
> +	{ BTN_TYPE_KB, 0x95, "KEY_END" },
> +	{ BTN_TYPE_KB, 0x97, "KEY_PAGEDOWN" },
> +	{ BTN_TYPE_KB, 0x98, "KEY_UP" },
> +	{ BTN_TYPE_KB, 0x99, "KEY_DOWN" },
> +	{ BTN_TYPE_KB, 0x9A, "KEY_LEFT" },
> +	{ BTN_TYPE_KB, 0x9B, "KEY_RIGHT" },
> +
> +	/* Numpad button codes */
> +	{ BTN_TYPE_KB, 0x77, "KEY_NUMLOCK" },
> +	{ BTN_TYPE_KB, 0x90, "KEY_KPSLASH" },
> +	{ BTN_TYPE_KB, 0x7C, "KEY_KPASTERISK" },
> +	{ BTN_TYPE_KB, 0x7B, "KEY_KPMINUS" },
> +	{ BTN_TYPE_KB, 0x70, "KEY_KP0" },
> +	{ BTN_TYPE_KB, 0x69, "KEY_KP1" },
> +	{ BTN_TYPE_KB, 0x72, "KEY_KP2" },
> +	{ BTN_TYPE_KB, 0x7A, "KEY_KP3" },
> +	{ BTN_TYPE_KB, 0x6B, "KEY_KP4" },
> +	{ BTN_TYPE_KB, 0x73, "KEY_KP5" },
> +	{ BTN_TYPE_KB, 0x74, "KEY_KP6" },
> +	{ BTN_TYPE_KB, 0x6C, "KEY_KP7" },
> +	{ BTN_TYPE_KB, 0x75, "KEY_KP8" },
> +	{ BTN_TYPE_KB, 0x7D, "KEY_KP9" },
> +	{ BTN_TYPE_KB, 0x79, "KEY_KPPLUS" },
> +	{ BTN_TYPE_KB, 0x81, "KEY_KPENTER" },
> +	{ BTN_TYPE_KB, 0x71, "KEY_KPDOT" },
> +
> +	/* Mouse button codes */
> +	{ BTN_TYPE_MOUSE, 0x01, "BTN_LEFT" },
> +	{ BTN_TYPE_MOUSE, 0x02, "BTN_RIGHT" },
> +	{ BTN_TYPE_MOUSE, 0x03, "BTN_MIDDLE" },
> +	{ BTN_TYPE_MOUSE, 0x04, "REL_WHEEL_HI_RES_UP" },
> +	{ BTN_TYPE_MOUSE, 0x05, "REL_WHEEL_HI_RES_DOWN" },
> +
> +	/* Media button codes */
> +	{ BTN_TYPE_MEDIA, 0x16, "MEDIA_SCREENSHOT" },
> +	{ BTN_TYPE_MEDIA, 0x19, "MEDIA_SHOW_KEYBOARD" },
> +	{ BTN_TYPE_MEDIA, 0x1C, "MEDIA_SHOW_DESKTOP" },
> +	{ BTN_TYPE_MEDIA, 0x1E, "MEDIA_START_RECORDING" },
> +	{ BTN_TYPE_MEDIA, 0x01, "MEDIA_MIC_OFF" },
> +	{ BTN_TYPE_MEDIA, 0x02, "MEDIA_VOL_DOWN" },
> +	{ BTN_TYPE_MEDIA, 0x03, "MEDIA_VOL_UP" },
> +};
> +
> +static const size_t keymap_len = ARRAY_SIZE(ally_btn_codes);

Why is this a variable???? Can't the users just directly use ARRAY_SIZE on 
the array????

At v11 it's odd to find this much garbage still remaining... :-(

> +static const struct btn_code_map *find_button_by_name(const char *name);

Could you reorder the code such that this is not necessary. Having the 
code here would be more logical as well because that relates to the array.

> +
> +static void ally_set_default_gamepad_mapping(struct ally_button_mapping *map)
> +{
> +	int i;
> +
> +	/* Set all pair indexes and initialize to NONE */
> +	for (i = 0; i < 9; i++) {

ARRAY_SIZE()

> +		map->button_pairs[i].pair_index = i + 1;
> +		map->button_pairs[i].first.remap =
> +			find_button_by_name("NONE");
> +		map->button_pairs[i].first.macro =
> +			find_button_by_name("NONE");
> +		map->button_pairs[i].second.remap =
> +			find_button_by_name("NONE");
> +		map->button_pairs[i].second.macro =
> +			find_button_by_name("NONE");

Why does this have to search for the NONE button multiple times?

> +	}
> +
> +	map->button_pairs[BTN_PAIR_AB - 1].first.remap =
> +		find_button_by_name("BTN_SOUTH");
> +	map->button_pairs[BTN_PAIR_AB - 1].second.remap =
> +		find_button_by_name("BTN_EAST");
> +
> +	map->button_pairs[BTN_PAIR_XY - 1].first.remap =
> +		find_button_by_name("BTN_NORTH");
> +	map->button_pairs[BTN_PAIR_XY - 1].second.remap =
> +		find_button_by_name("BTN_WEST");
> +
> +	map->button_pairs[BTN_PAIR_BUMPER_LR - 1].first.remap =
> +		find_button_by_name("BTN_TL");
> +	map->button_pairs[BTN_PAIR_BUMPER_LR - 1].second.remap =
> +		find_button_by_name("BTN_TR");
> +
> +	map->button_pairs[BTN_PAIR_STICK_LR - 1].first.remap =
> +		find_button_by_name("BTN_THUMBL");
> +	map->button_pairs[BTN_PAIR_STICK_LR - 1].second.remap =
> +		find_button_by_name("BTN_THUMBR");
> +
> +	map->button_pairs[BTN_PAIR_DPAD_UPDOWN - 1].first.remap =
> +		find_button_by_name("ABS_HAT0Y_NEG");
> +	map->button_pairs[BTN_PAIR_DPAD_UPDOWN - 1].second.remap =
> +		find_button_by_name("ABS_HAT0Y_POS");
> +
> +	map->button_pairs[BTN_PAIR_DPAD_LEFTRIGHT - 1].first.remap =
> +		find_button_by_name("ABS_HAT0X_NEG");
> +	map->button_pairs[BTN_PAIR_DPAD_LEFTRIGHT - 1].second.remap =
> +		find_button_by_name("ABS_HAT0X_POS");
> +
> +	map->button_pairs[BTN_PAIR_TRIGGER_LR - 1].first.remap =
> +		find_button_by_name("ABS_Z");
> +	map->button_pairs[BTN_PAIR_TRIGGER_LR - 1].second.remap =
> +		find_button_by_name("ABS_RZ");
> +
> +	map->button_pairs[BTN_PAIR_VIEW_MENU - 1].first.remap =
> +		find_button_by_name("BTN_SELECT");
> +	map->button_pairs[BTN_PAIR_VIEW_MENU - 1].second.remap =
> +		find_button_by_name("BTN_START");
> +
> +	map->button_pairs[BTN_PAIR_M1M2 - 1].first.remap =
> +		find_button_by_name("FN_M2");
> +	map->button_pairs[BTN_PAIR_M1M2 - 1].second.remap =
> +		find_button_by_name("FN_M1");
> +}
> +
> +static void ally_set_default_keyboard_mapping(struct ally_button_mapping *map)
> +{
> +	int i;
> +
> +	/* Set all pair indexes and initialize to NONE */
> +	for (i = 0; i < 9; i++) {
> +		map->button_pairs[i].pair_index = i + 1;
> +		map->button_pairs[i].first.remap =
> +			find_button_by_name("NONE");
> +		map->button_pairs[i].first.macro =
> +			find_button_by_name("NONE");
> +		map->button_pairs[i].second.remap =
> +			find_button_by_name("NONE");
> +		map->button_pairs[i].second.macro =
> +			find_button_by_name("NONE");
> +	}

Duplicated code with the very same problems!

> +	/*
> +	 * Desktop mode defaults: keyboard and mouse mappings.
> +	 * Buttons not listed here (dpad, view, menu) remain NONE.
> +	 */
> +
> +	/* btn_a => KEY_SPACE, btn_b => KEY_E */
> +	map->button_pairs[BTN_PAIR_AB - 1].first.remap =
> +		find_button_by_name("KEY_SPACE");
> +	map->button_pairs[BTN_PAIR_AB - 1].second.remap =
> +		find_button_by_name("KEY_E");
> +
> +	/* btn_x => KEY_R, btn_y => KEY_F */
> +	map->button_pairs[BTN_PAIR_XY - 1].first.remap =
> +		find_button_by_name("KEY_R");
> +	map->button_pairs[BTN_PAIR_XY - 1].second.remap =
> +		find_button_by_name("KEY_F");
> +
> +	/* LB => wheel up, RB => wheel down */
> +	map->button_pairs[BTN_PAIR_BUMPER_LR - 1].first.remap =
> +		find_button_by_name("REL_WHEEL_HI_RES_UP");
> +	map->button_pairs[BTN_PAIR_BUMPER_LR - 1].second.remap =
> +		find_button_by_name("REL_WHEEL_HI_RES_DOWN");
> +
> +	/* left stick click => left click, right stick click => left shift */
> +	map->button_pairs[BTN_PAIR_STICK_LR - 1].first.remap =
> +		find_button_by_name("BTN_LEFT");
> +	map->button_pairs[BTN_PAIR_STICK_LR - 1].second.remap =
> +		find_button_by_name("KEY_LEFTSHIFT");
> +
> +	/* LT => left click, RT => right click */
> +	map->button_pairs[BTN_PAIR_TRIGGER_LR - 1].first.remap =
> +		find_button_by_name("BTN_LEFT");
> +	map->button_pairs[BTN_PAIR_TRIGGER_LR - 1].second.remap =
> +		find_button_by_name("BTN_RIGHT");
> +
> +	/* M2 => FN_M2, M1 => FN_M1 */
> +	map->button_pairs[BTN_PAIR_M1M2 - 1].first.remap =
> +		find_button_by_name("FN_M2");
> +	map->button_pairs[BTN_PAIR_M1M2 - 1].second.remap =
> +		find_button_by_name("FN_M1");
> +}
> +
>  static ssize_t gamepad_mode_show(struct device *dev, struct device_attribute *attr, char *buf)
>  {
>  	struct hid_device *hdev = to_hid_device(dev);
> @@ -1113,7 +1452,7 @@ static ssize_t gamepad_mode_store(struct device *dev, struct device_attribute *a
>  	struct ally_config *cfg;
>  	u8 mode_byte;
>  	int mode;
> -	int ret;
> +	int ret, i;
>  
>  	if (!ally)
>  		return -ENODEV;
> @@ -1141,6 +1480,33 @@ static ssize_t gamepad_mode_store(struct device *dev, struct device_attribute *a
>  
>  	cfg->gamepad_mode = mode_byte;
>  
> +	/*
> +	 * When the gamepad mode changes, the hardware automatically
> +	 * resets all button mappings to its internal defaults for the
> +	 * new mode.
> +	 *
> +	 * Refresh the software cache so that subsequent
> +	 * reads from sysfs reflect what the firmware is actually
> +	 * using.
> +	 */
> +	if (mode_byte == ALLY_GAMEPAD_MODE_GAMEPAD)
> +		ally_set_default_gamepad_mapping(&cfg->button_mappings);
> +	else if (mode_byte == ALLY_GAMEPAD_MODE_KEYBOARD)
> +		ally_set_default_keyboard_mapping(&cfg->button_mappings);
> +
> +	/*
> +	 * The re-defaulted mappings are what the remap and macro files
> +	 * report: wake anyone polling them about the new values.
> +	 */
> +	if (cfg->button_entries) {
> +		for (i = 0; i < ALLY_BTN_MAX; i++) {
> +			sysfs_notify(&dev->kobj, cfg->button_entries[i].group.name,
> +				     "remap");
> +			sysfs_notify(&dev->kobj, cfg->button_entries[i].group.name,
> +				     "macro");
> +		}
> +	}
> +
>  	hid_dbg(hdev, "Set gamepad mode to %s\n", ally_gamepad_mode_text[mode]);
>  
>  	sysfs_notify(&dev->kobj, NULL, "gamepad_mode");
> @@ -2815,6 +3181,575 @@ static void ally_btn_turbo_init_attrs(struct ally_btn_sysfs_entry *entry)
>  	entry->attrs[4] = NULL;
>  }
>  
> +/**
> + * find_button_by_name() - Find a button code map by its name
> + * @name: name of the button code to look up
> + *
> + * Return: the matching button code map, or NULL if not found
> + */
> +static const struct btn_code_map *find_button_by_name(const char *name)
> +{
> +	int i;
> +
> +	for (i = 0; i < keymap_len; i++) {
> +		if (strcmp(ally_btn_codes[i].name, name) == 0)

!strcmp()

You probably should check if you've the include for strcmp(), could be 
necessary for some other patch too, I've lost track what includes have 
been added so far.

> +			return &ally_btn_codes[i];
> +	}
> +
> +	return NULL;
> +}
> +
> +/**
> + * ally_remap_code_valid() - Check if a remap target is valid for a button
> + * @btn: button to remap
> + * @gamepad_mode: gamepad mode to validate the remap against
> + * @code: remap target to check
> + * @is_macro: whether the target is assigned to the macro mapping
> + *
> + * M1 and M2 can be remapped to anything at any time.
> + * All other buttons may only be remapped to gamepad buttons (BTN_TYPE_PAD)
> + * when in gamepad mode, and to keyboard/mouse/media codes when in desktop
> + * (keyboard) mode.  BTN_TYPE_NONE (unmapped) is always allowed.
> + * Macro mappings are executed by the MCU as input sequences on the virtual
> + * keyboard and are accepted regardless of the current gamepad mode.
> + *
> + * Return: true if the remap is valid, false otherwise
> + */
> +static bool ally_remap_code_valid(enum ally_button_id btn, u8 gamepad_mode,
> +				  const struct btn_code_map *code, bool is_macro)
> +{
> +	if (!code)
> +		return false;
> +
> +	/* M1 and M2 can be remapped to everything */
> +	if (btn == ALLY_BTN_M1 || btn == ALLY_BTN_M2)
> +		return true;
> +
> +	/* NONE is always valid */
> +	if (code->type == BTN_TYPE_NONE)
> +		return true;
> +
> +	/* Macros are not restricted by the controller emulation mode */
> +	if (is_macro)
> +		return true;
> +
> +	if (gamepad_mode == ALLY_GAMEPAD_MODE_GAMEPAD)
> +		return code->type == BTN_TYPE_PAD;
> +
> +	/* Desktop / keyboard mode: allow keyboard, mouse and media */
> +	return code->type == BTN_TYPE_KB ||
> +	       code->type == BTN_TYPE_MOUSE ||
> +	       code->type == BTN_TYPE_MEDIA;
> +}
> +
> +/**
> + * ally_set_button_mapping() - Set the button mapping for a button pair
> + * @hdev: HID device
> + * @ally: ally handheld structure
> + * @mapping: button pair mapping to send to the device
> + *
> + * Return: count of data transferred, negative if error
> + */
> +static int ally_set_button_mapping(struct hid_device *hdev, struct ally_handheld *ally,
> +				   struct button_pair_map *mapping)
> +{
> +	/* The MCU mapping block is four consecutive 11-byte entries starting at

Inconsistent multi-line comment style.

> +	 * buf[5]: first remap 5-15, first macro 16-26, second remap 27-37,
> +	 * second macro 38-48 (see hid-asus-ally __btn_pair_to_pkt, BTN_CODE_LEN).

I didn't find __btn_pair_to_pkt from anywhere?? Nor BTN_CODE_LEN??

> +	 */
> +	u8 macro_bytes[11] = {0};
> +	u8 btn_bytes[11] = {0};

= {} initializes to default values which is 0 for u8.

> +
> +	if (!mapping || !mapping->first.remap || !mapping->first.macro ||
> +	    !mapping->second.remap || !mapping->second.macro)
> +		return -EINVAL;
> +
> +	u8 *buf __free(kfree) = ally_alloc_cmd(CMD_SET_MAPPING, NULL, 0);
> +	if (!buf)
> +		return -ENOMEM;
> +
> +	/* This packet is slightly different from the other

Comment style.

> +	 * as before the packet length there is an extra byte
> +	 * which is the pair index.
> +	 */
> +	buf[3] = mapping->pair_index;
> +	buf[4] = 0x2C; /* Length */

Use named define or sizeof() (if viable).

> +
> +	/* First button mapping */
> +	buf[5] = mapping->first.remap->type;
> +	/* Fill in bytes 6-14 with button code */
> +	if (mapping->first.remap->type) {
> +		memset(btn_bytes, 0, sizeof(btn_bytes));
> +		btn_bytes[0] = mapping->first.remap->type;
> +
> +		/* Value byte position depends on type: pad=1, kb=2, media=3,

Comment style.

> +		 * mouse=4 (see hid-asus-ally BTN_CODE definitions).
> +		 */
> +		switch (mapping->first.remap->type) {
> +		case BTN_TYPE_NONE:
> +			break;
> +		case BTN_TYPE_PAD:
> +			btn_bytes[1] = mapping->first.remap->value;
> +			break;
> +		case BTN_TYPE_KB:
> +			btn_bytes[2] = mapping->first.remap->value;
> +			break;
> +		case BTN_TYPE_MEDIA:
> +			btn_bytes[3] = mapping->first.remap->value;
> +			break;
> +		case BTN_TYPE_MOUSE:
> +			btn_bytes[4] = mapping->first.remap->value;
> +			break;
> +		}
> +		memcpy(&buf[5], btn_bytes, 11);

Magic 11. Please name properly.

I wonder though if there should be helpers for these with a few parameters 
as these seem mostly just duplicated multiple times.

> +	}
> +
> +	/* Macro mapping for first button if any */
> +	buf[16] = mapping->first.macro->type;
> +	if (mapping->first.macro->type) {
> +		memset(macro_bytes, 0, sizeof(macro_bytes));
> +		macro_bytes[0] = mapping->first.macro->type;
> +
> +		switch (mapping->first.macro->type) {
> +		case BTN_TYPE_NONE:
> +			break;
> +		case BTN_TYPE_PAD:
> +			macro_bytes[1] = mapping->first.macro->value;
> +			break;
> +		case BTN_TYPE_KB:
> +			macro_bytes[2] = mapping->first.macro->value;
> +			break;
> +		case BTN_TYPE_MEDIA:
> +			macro_bytes[3] = mapping->first.macro->value;
> +			break;
> +		case BTN_TYPE_MOUSE:
> +			macro_bytes[4] = mapping->first.macro->value;
> +			break;
> +		}
> +		memcpy(&buf[16], macro_bytes, 11);

Magic 11.

> +	}
> +
> +	/* Second button mapping */
> +	buf[27] = mapping->second.remap->type;
> +	/* Fill in bytes 28-36 with button code */
> +	if (mapping->second.remap->type) {
> +		memset(btn_bytes, 0, sizeof(btn_bytes));
> +		btn_bytes[0] = mapping->second.remap->type;
> +
> +		switch (mapping->second.remap->type) {
> +		case BTN_TYPE_NONE:
> +			break;
> +		case BTN_TYPE_PAD:
> +			btn_bytes[1] = mapping->second.remap->value;
> +			break;
> +		case BTN_TYPE_KB:
> +			btn_bytes[2] = mapping->second.remap->value;
> +			break;
> +		case BTN_TYPE_MEDIA:
> +			btn_bytes[3] = mapping->second.remap->value;
> +			break;
> +		case BTN_TYPE_MOUSE:
> +			btn_bytes[4] = mapping->second.remap->value;
> +			break;
> +		}
> +		memcpy(&buf[27], btn_bytes, 11);

Ditto.

> +	}
> +
> +	/* Macro mapping for second button if any */
> +	buf[38] = mapping->second.macro->type;
> +	if (mapping->second.macro->type) {
> +		memset(macro_bytes, 0, sizeof(macro_bytes));
> +		macro_bytes[0] = mapping->second.macro->type;
> +
> +		switch (mapping->second.macro->type) {
> +		case BTN_TYPE_NONE:
> +			break;
> +		case BTN_TYPE_PAD:
> +			macro_bytes[1] = mapping->second.macro->value;
> +			break;
> +		case BTN_TYPE_KB:
> +			macro_bytes[2] = mapping->second.macro->value;
> +			break;
> +		case BTN_TYPE_MEDIA:
> +			macro_bytes[3] = mapping->second.macro->value;
> +			break;
> +		case BTN_TYPE_MOUSE:
> +			macro_bytes[4] = mapping->second.macro->value;
> +			break;
> +		}
> +		memcpy(&buf[38], macro_bytes, 11);

Ditto.

> +	}
> +
> +	return ally_gamepad_send_packet(ally, hdev, buf, ROG_ALLY_REPORT_SIZE);
> +}
> +
> +/**
> + * ally_apply_button_mappings() - Push the recorded mappings of the current
> + * gamepad mode to the controller
> + * @hdev: HID device
> + * @ally: ally handheld structure
> + * @cfg: ally config structure
> + *
> + * An MCU reset restores the firmware default mappings: push the recorded
> + * ones again so that the hardware keeps matching what userspace
> + * configured. The caller must hold cfg->config_mutex, exactly like the
> + * sysfs store callbacks that update single pairs.
> + */
> +static void ally_apply_button_mappings(struct hid_device *hdev,
> +				       struct ally_handheld *ally,
> +				       struct ally_config *cfg)
> +{
> +	struct ally_button_mapping *mode_map;
> +	int i, ret;
> +
> +	mode_map = &cfg->button_mappings;
> +
> +	for (i = 0; i < ARRAY_SIZE(mode_map->button_pairs); i++) {
> +		mode_map->button_pairs[i].pair_index = i + 1;
> +
> +		ret = ally_set_button_mapping(hdev, ally,
> +					      &mode_map->button_pairs[i]);
> +		if (ret < 0) {
> +			hid_warn(hdev,
> +				 "Failed to restore button mappings: %d\n",
> +				 ret);
> +			return;
> +		}
> +	}
> +}
> +
> +/**
> + * get_button_pair_info() - Get the pair index and position of a button
> + * @button_id: button to look up
> + * @pair_idx: output pointer for the pair index of the button
> + * @is_first: output pointer for the position of the button within the pair
> + *
> + * Return: 0 on success, negative errno on failure
> + */
> +static int get_button_pair_info(enum ally_button_id button_id,
> +				enum btn_pair_index *pair_idx,
> +				bool *is_first)
> +{
> +	switch (button_id) {
> +	case ALLY_BTN_DU:
> +		*pair_idx = BTN_PAIR_DPAD_UPDOWN;
> +		*is_first = true;
> +		break;
> +	case ALLY_BTN_DD:
> +		*pair_idx = BTN_PAIR_DPAD_UPDOWN;
> +		*is_first = false;
> +		break;
> +	case ALLY_BTN_DL:
> +		*pair_idx = BTN_PAIR_DPAD_LEFTRIGHT;
> +		*is_first = true;
> +		break;
> +	case ALLY_BTN_DR:
> +		*pair_idx = BTN_PAIR_DPAD_LEFTRIGHT;
> +		*is_first = false;
> +		break;
> +	case ALLY_BTN_J0B:
> +		*pair_idx = BTN_PAIR_STICK_LR;
> +		*is_first = true;
> +		break;
> +	case ALLY_BTN_J1B:
> +		*pair_idx = BTN_PAIR_STICK_LR;
> +		*is_first = false;
> +		break;
> +	case ALLY_BTN_LB:
> +		*pair_idx = BTN_PAIR_BUMPER_LR;
> +		*is_first = true;
> +		break;
> +	case ALLY_BTN_RB:
> +		*pair_idx = BTN_PAIR_BUMPER_LR;
> +		*is_first = false;
> +		break;
> +	case ALLY_BTN_A:
> +		*pair_idx = BTN_PAIR_AB;
> +		*is_first = true;
> +		break;
> +	case ALLY_BTN_B:
> +		*pair_idx = BTN_PAIR_AB;
> +		*is_first = false;
> +		break;
> +	case ALLY_BTN_X:
> +		*pair_idx = BTN_PAIR_XY;
> +		*is_first = true;
> +		break;
> +	case ALLY_BTN_Y:
> +		*pair_idx = BTN_PAIR_XY;
> +		*is_first = false;
> +		break;
> +	case ALLY_BTN_VIEW:
> +		*pair_idx = BTN_PAIR_VIEW_MENU;
> +		*is_first = true;
> +		break;
> +	case ALLY_BTN_MENU:
> +		*pair_idx = BTN_PAIR_VIEW_MENU;
> +		*is_first = false;
> +		break;
> +	case ALLY_BTN_M1:
> +		*pair_idx = BTN_PAIR_M1M2;
> +		*is_first = false;
> +		break;
> +	case ALLY_BTN_M2:
> +		*pair_idx = BTN_PAIR_M1M2;
> +		*is_first = true;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static ssize_t button_remap_show(struct device *dev,
> +				 struct device_attribute *attr, char *buf)
> +{
> +	struct button_remap_attr *btn_attr = to_button_remap_attr(attr);
> +	struct ally_handheld *ally = btn_attr->ally;
> +	const struct btn_code_map *code;
> +	struct ally_config *cfg;
> +	enum ally_button_id button_id = btn_attr->button_id;
> +	enum btn_pair_index pair_idx;
> +	struct button_pair_map *pair;
> +	struct button_map *btn_map;
> +	bool is_first;
> +	int ret;
> +
> +	if (!ally)
> +		return -ENODEV;
> +
> +	cfg = ally_get_config(ally);
> +	if (!cfg)
> +		return -ENODEV;
> +
> +	ret = get_button_pair_info(button_id, &pair_idx, &is_first);
> +	if (ret < 0)
> +		return ret;
> +
> +	guard(mutex)(&cfg->config_mutex);
> +
> +	pair = &cfg->button_mappings.button_pairs[pair_idx - 1];
> +	btn_map = is_first ? &pair->first : &pair->second;
> +	code = btn_attr->is_macro ? btn_map->macro : btn_map->remap;
> +
> +	/*
> +	 * The mappings are never NULL: the defaults, the mode-switch
> +	 * re-defaults and the store rollback all guarantee it. A miss
> +	 * means a broken default table, so fail loudly instead of
> +	 * dereferencing.
> +	 */
> +	if (!code)
> +		return -EIO;
> +
> +	if (code->type == BTN_TYPE_NONE)
> +		return sysfs_emit(buf, "NONE\n");

Wouldn't it emit "NONE" anyway with the normal return so why you need 
special print for this separately?

> +
> +	return sysfs_emit(buf, "%s\n", code->name);
> +}
> +
> +static ssize_t button_remap_store(struct device *dev,
> +				  struct device_attribute *attr,
> +				  const char *buf, size_t count)
> +{
> +	struct hid_device *hdev = to_hid_device(dev);
> +	struct button_remap_attr *btn_attr = to_button_remap_attr(attr);
> +	struct ally_handheld *ally = btn_attr->ally;
> +	enum ally_button_id button_id = btn_attr->button_id;
> +	struct ally_button_mapping *mode_map;
> +	const struct btn_code_map *code;
> +	const struct btn_code_map *old_code;
> +	enum btn_pair_index pair_idx;
> +	struct button_pair_map *pair;
> +	struct button_map *btn_map;
> +	struct ally_config *cfg;
> +	char btn_name[32];
> +	bool is_first;
> +	bool undo_hw;
> +	int ret, i;
> +
> +	if (!ally)
> +		return -ENODEV;
> +
> +	cfg = ally_get_config(ally);
> +	if (!cfg)
> +		return -ENODEV;
> +
> +	if (sscanf(buf, "%31s", btn_name) != 1)
> +		return -EINVAL;
> +
> +	/* Handle "NONE" specially */

Yeah yeah, and now you better must explain me why???? This is totally 
useless comment and helps zero to explain why the code is making things 
in a stupid way.

Won't find_button_by_name() return the very same entry???

(You can see probably I'm starting to get tired of reading this kind of 
things at this point... ...I've read quite many lines by now.)

> +	if (strcmp(btn_name, "NONE") == 0) {

!strcmp(), but it looks totally useless check (see above).

> +		code = &ally_btn_codes[0]; /* NONE entry */
> +	} else {
> +		code = find_button_by_name(btn_name);
> +		if (!code)
> +			return -EINVAL;
> +	}
> +
> +	ret = get_button_pair_info(button_id, &pair_idx, &is_first);
> +	if (ret < 0)
> +		return ret;
> +
> +	guard(mutex)(&cfg->config_mutex);
> +
> +	/*
> +	 * Validate the remap target while holding the lock: the
> +	 * gamepad mode can change concurrently, and the check must
> +	 * be done against the very mode the mapping is written to.
> +	 */
> +	if (!ally_remap_code_valid(button_id, cfg->gamepad_mode, code,
> +				   btn_attr->is_macro))
> +		return -EINVAL;
> +
> +	/* Access the mapping for current gamepad mode */
> +	pair = &cfg->button_mappings.button_pairs[pair_idx - 1];
> +	btn_map = is_first ? &pair->first : &pair->second;
> +
> +	if (btn_attr->is_macro) {
> +		old_code = btn_map->macro;
> +		btn_map->macro = code;
> +	} else {
> +		old_code = btn_map->remap;
> +		btn_map->remap = code;
> +	}
> +
> +	/* Update pair index */
> +	pair->pair_index = pair_idx;
> +
> +	/*
> +	 * Send mapping to device with the caveat that first
> +	 * generation devices require individual button pair updates.
> +	 */
> +	if (cfg->is_ally_x) {
> +		ret = ally_set_button_mapping(hdev, ally, pair);
> +		undo_hw = false;
> +	} else {
> +		mode_map = &cfg->button_mappings;
> +		ret = 0;

Is this required?

> +		for (i = 0; i < 9; i++) {

ARRAY_SIZE()

> +			mode_map->button_pairs[i].pair_index = i + 1;
> +			ret = ally_set_button_mapping(hdev, ally,
> +						      &mode_map->button_pairs[i]);
> +			if (ret < 0)
> +				break;

IMO, it would be better to use goto to deal with these errors (here and 
above in the if blcok).

> +		}
> +
> +		/*
> +		 * Pairs are pushed one at a time: remember whether
> +		 * the target pair reached the hardware before a
> +		 * later pair failed, so the rollback below can undo
> +		 * it on the device too.
> +		 */
> +		undo_hw = ret < 0 && i > pair_idx - 1;

Do this above before goto.

> +	}
> +
> +	/*
> +	 * The hardware rejected the update: restore the previous
> +	 * mapping so that the software cache keeps describing the
> +	 * state the device is actually in.
> +	 */
> +	if (ret < 0) {
> +		if (btn_attr->is_macro)
> +			btn_map->macro = old_code;
> +		else
> +			btn_map->remap = old_code;
> +
> +		/*
> +		 * The target pair was already committed before a
> +		 * later pair failed: push the restored mapping once
> +		 * more so the hardware matches the cache again. Best
> +		 * effort only: the device is misbehaving already.
> +		 */
> +		if (undo_hw)
> +			ally_set_button_mapping(hdev, ally, pair);
> +
> +		hid_err(hdev, "Failed to set button mapping: %d\n", ret);
> +		return ret;
> +	}
> +
> +	sysfs_notify(&dev->kobj, ally_button_names[btn_attr->button_id],
> +		     btn_attr->is_macro ? "macro" : "remap");

I suggest adding a local string_choices.h style str_macro_remap() for this 
as it seems to occur a few time.

> +
> +	return count;
> +}
> +
> +/**
> + * button_remap_attr_create() - Create a button remap attribute
> + * @ally: ally handheld structure
> + * @button_id: button the attribute is for
> + * @is_macro: whether the attribute controls the macro mapping
> + *
> + * Return: the newly created attribute, or NULL on allocation failure
> + */
> +static struct button_remap_attr *button_remap_attr_create(struct ally_handheld *ally,
> +							  enum ally_button_id button_id,
> +							  bool is_macro)
> +{
> +	struct button_remap_attr *attr __free(kfree) = kzalloc_obj(*attr);
> +	if (!attr)
> +		return NULL;
> +
> +	attr->ally = ally;
> +	attr->button_id = button_id;
> +	attr->is_macro = is_macro;
> +	sysfs_attr_init(&attr->dev_attr.attr);
> +	attr->dev_attr.attr.name = is_macro ? "macro" : "remap";
> +	attr->dev_attr.attr.mode = 0644;
> +	attr->dev_attr.show = button_remap_show;
> +	attr->dev_attr.store = button_remap_store;
> +
> +	return no_free_ptr(attr);

You don't need to use __free()/no_free_ptr() in this function because 
only return is due to alloc fail check (attr is NULL at that point and 
kfree(NULL) is no-op).

> +}
> +
> +/**
> + * btn_remap_index_show() - Show the list of valid remap targets for a button
> + * @dev: device the attribute belongs to
> + * @attr: attribute being read
> + * @buf: buffer to write the list into
> + *
> + * M1/M2 list everything; other buttons list only the codes valid for the
> + * active mode (gamepad buttons in gamepad mode, keyboard / mouse / media
> + * in desktop mode).
> + *
> + * Return: number of characters written
> + */
> +static ssize_t btn_remap_index_show(struct device *dev,
> +				    struct device_attribute *attr, char *buf)
> +{
> +	struct hid_device *hdev = to_hid_device(dev);
> +	struct asus_drvdata *drvdata = hid_get_drvdata(hdev);
> +	struct ally_handheld *ally = drvdata->rog_ally;
> +	struct ally_btn_sysfs_entry *entry = container_of(attr,
> +		struct ally_btn_sysfs_entry, attr_remap_index);
> +	struct ally_config *cfg;
> +	enum ally_button_id btn = entry->btn;
> +	u8 mode;
> +	ssize_t len = 0;
> +	int i;
> +
> +	if (!ally)
> +		return -ENODEV;
> +
> +	cfg = ally_get_config(ally);
> +	if (!cfg)
> +		return -ENODEV;
> +
> +	scoped_guard(mutex, &cfg->config_mutex)
> +		mode = cfg->gamepad_mode;
> +
> +	for (i = 0; i < keymap_len; i++) {
> +		if (!ally_remap_code_valid(btn, mode, &ally_btn_codes[i], false))
> +			continue;
> +		len += sysfs_emit_at(buf, len, "%s ", ally_btn_codes[i].name);
> +	}
> +
> +	if (len > 0)
> +		buf[len - 1] = '\n';
> +
> +	return len;
> +}
> +
>  /**
>   * ally_create_button_attributes() - Create turbo button attributes
>   * @hdev: HID device
> @@ -2824,15 +3759,12 @@ static void ally_btn_turbo_init_attrs(struct ally_btn_sysfs_entry *entry)
>   * Return: 0 on success, negative errno on failure
>   */
>  static int ally_create_button_attributes(struct hid_device *hdev,
> -					 struct ally_handheld *ally,
> -					 struct ally_config *cfg)
> +					  struct ally_handheld *ally,
> +					  struct ally_config *cfg)
>  {
>  	struct ally_btn_sysfs_entry *entries;
>  	int i, ret;
>  
> -	if (!cfg->turbo_support)
> -		return 0;
> -
>  	entries = kcalloc(ALLY_BTN_MAX, sizeof(*entries), GFP_KERNEL);
>  	if (!entries)
>  		return -ENOMEM;
> @@ -2845,13 +3777,53 @@ static int ally_create_button_attributes(struct hid_device *hdev,
>  		entries[i].hdev = hdev;
>  		entries[i].btn = i;
>  
> -		if (!ally_btn_get_turbo_params(cfg, i)) {
> -			hid_err(hdev, "Invalid button id %d for turbo attributes\n", i);
> -			ret = -EINVAL;
> +		if (cfg->turbo_support) {
> +			if (!ally_btn_get_turbo_params(cfg, i)) {
> +				hid_err(hdev, "Invalid button id %d for turbo attributes\n", i);
> +				ret = -EINVAL;
> +				goto err_cleanup;
> +			}
> +
> +			ally_btn_turbo_init_attrs(&entries[i]);
> +		}
> +
> +		entries[i].remap_attr = button_remap_attr_create(ally, i, false);
> +		if (!entries[i].remap_attr) {
> +			ret = -ENOMEM;
>  			goto err_cleanup;
>  		}
>  
> -		ally_btn_turbo_init_attrs(&entries[i]);
> +		entries[i].macro_attr = button_remap_attr_create(ally, i, true);
> +		if (!entries[i].macro_attr) {
> +			ret = -ENOMEM;
> +			goto err_cleanup;
> +		}
> +
> +		/* Initialize the remap_index attribute */
> +		sysfs_attr_init(&entries[i].attr_remap_index.attr);
> +		entries[i].attr_remap_index.attr.name = "remap_index";
> +		entries[i].attr_remap_index.attr.mode = 0444;
> +		entries[i].attr_remap_index.show = btn_remap_index_show;
> +		entries[i].attr_remap_index.store = NULL;
> +
> +		/* Set up attributes array based on what's supported */
> +		if (cfg->turbo_support) {
> +			entries[i].attrs[4] =
> +				&entries[i].remap_attr->dev_attr.attr;
> +			entries[i].attrs[5] =
> +				&entries[i].macro_attr->dev_attr.attr;
> +			entries[i].attrs[6] =
> +				&entries[i].attr_remap_index.attr;
> +			entries[i].attrs[7] = NULL;
> +		} else {
> +			entries[i].attrs[0] =
> +				&entries[i].remap_attr->dev_attr.attr;
> +			entries[i].attrs[1] =
> +				&entries[i].macro_attr->dev_attr.attr;
> +			entries[i].attrs[2] =
> +				&entries[i].attr_remap_index.attr;
> +			entries[i].attrs[3] = NULL;

So only the attrs index changed?? Why all the duplication?

> +		}
>  
>  		entries[i].group.name = ally_button_names[i];
>  		entries[i].group.attrs = entries[i].attrs;
> @@ -2867,12 +3839,27 @@ static int ally_create_button_attributes(struct hid_device *hdev,
>  	return 0;
>  
>  err_cleanup:
> +	/*
> +	 * Unpublish first: the readers of button_entries (like the
> +	 * gamepad_mode_store() cross-notification) hold config_mutex and
> +	 * must observe either the live array or NULL, never a freed one.
> +	 * The lock is released again before the removals, so a straggler
> +	 * callback waiting on it can drain against the not yet freed
> +	 * entries.
> +	 */
> +	scoped_guard(mutex, &cfg->config_mutex) {
> +		cfg->button_entries = NULL;
> +	}
> +
>  	while (--i >= 0)
>  		sysfs_remove_group(&hdev->dev.kobj, &entries[i].group);
>  
> -	kfree(entries);
> +	for (i = 0; i < ALLY_BTN_MAX; i++) {
> +		kfree(entries[i].remap_attr);
> +		kfree(entries[i].macro_attr);
> +	}
>  
> -	cfg->button_entries = NULL;
> +	kfree(entries);
>  
>  	return ret;
>  }
> @@ -2892,12 +3879,26 @@ static void ally_remove_button_attributes(struct hid_device *hdev, struct ally_c
>  
>  	entries = cfg->button_entries;
>  
> -	for (i = 0; i < ALLY_BTN_MAX; i++)
> +	/*
> +	 * Unpublish first: the readers of button_entries (like the
> +	 * gamepad_mode_store() cross-notification) hold config_mutex and
> +	 * must observe either the live array or NULL, never a freed one.
> +	 * The lock is released again before the removals, so a straggler
> +	 * callback waiting on it can drain against the not yet freed
> +	 * entries, and sysfs_remove_group() waits for the last ones to
> +	 * finish before the memory goes away.
> +	 */
> +	scoped_guard(mutex, &cfg->config_mutex) {
> +		cfg->button_entries = NULL;
> +	}
> +
> +	for (i = 0; i < ALLY_BTN_MAX; i++) {
>  		sysfs_remove_group(&hdev->dev.kobj, &entries[i].group);
> +		kfree(entries[i].remap_attr);
> +		kfree(entries[i].macro_attr);
> +	}
>  
>  	kfree(entries);
> -
> -	cfg->button_entries = NULL;
>  }
>  
>  /**
> @@ -2938,6 +3939,13 @@ static struct ally_config *ally_config_create(struct hid_device *hdev, struct al
>  
>  	if (!cfg->initialized) {
>  		cfg->gamepad_mode = ALLY_GAMEPAD_MODE_GAMEPAD;
> +		/*
> +		 * Populate the button mappings for the default mode: a mode
> +		 * switch re-defaults them, while on a later probe they hold
> +		 * the values the user configured, which are what the restore
> +		 * path re-applies to the controller.
> +		 */
> +		ally_set_default_gamepad_mapping(&cfg->button_mappings);
>  		cfg->xbox_controller_enabled = true;
>  		cfg->left_deadzone = 10;
>  		cfg->left_outer_threshold = 90;
> @@ -3010,12 +4018,15 @@ static struct ally_config *ally_config_create(struct hid_device *hdev, struct al
>  		cal_created = ARRAY_SIZE(ally_cal_attr_groups);
>  	}
>  
> -	if (cfg->turbo_support) {
> -		ret = ally_create_button_attributes(hdev, ally, cfg);
> -		if (ret < 0) {
> -			hid_err(hdev, "Failed to create button attributes: %d\n", ret);
> -			goto ally_config_create_sysfs_err;
> -		}
> +	/*
> +	 * The button attributes carry the remap/macro attributes too, so
> +	 * they are created for every device with button directories, not
> +	 * only the ones with turbo support.
> +	 */
> +	ret = ally_create_button_attributes(hdev, ally, cfg);
> +	if (ret < 0) {
> +		hid_err(hdev, "Failed to create button attributes: %d\n", ret);
> +		goto ally_config_create_sysfs_err;
>  	}
>  
>  	cfg->initialized = true;
> @@ -3610,6 +4621,10 @@ static int hid_asus_ally_init(struct hid_device *hdev, struct ally_handheld *all
>  				 ret);
>  	}
>  
> +	/* The mappings exist only if the button attributes were created. */
> +	if (cfg->button_entries)
> +		ally_apply_button_mappings(hdev, ally, cfg);
> +
>  	return 0;
>  }
>  
> 

-- 
 i.