diff --git a/Documentation/input/event-codes.rst b/Documentation/input/event-codes.rst index a8c0873beb95..cef220c176a4 100644 --- a/Documentation/input/event-codes.rst +++ b/Documentation/input/event-codes.rst @@ -190,7 +190,16 @@ A few EV_REL codes have special meanings: * REL_WHEEL, REL_HWHEEL: - These codes are used for vertical and horizontal scroll wheels, - respectively. + respectively. The value is the number of "notches" moved on the wheel, the + physical size of which varies by device. For high-resolution wheels (which + report multiple events for each notch of movement, or do not have notches) + this may be an approximation based on the high-resolution scroll events. + +* REL_WHEEL_HI_RES: + + - If a vertical scroll wheel supports high-resolution scrolling, this code + will be emitted in addition to REL_WHEEL. The value is the (approximate) + distance travelled by the user's finger, in microns. EV_ABS ------ diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index ad823a01bd65..567c3bf64515 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -1838,3 +1838,48 @@ void hidinput_disconnect(struct hid_device *hid) } EXPORT_SYMBOL_GPL(hidinput_disconnect); +/** + * hid_scroll_counter_handle_scroll() - Send high- and low-resolution scroll + * events given a high-resolution wheel + * movement. + * @counter: a hid_scroll_counter struct describing the wheel. + * @hi_res_value: the movement of the wheel, in the mouse's high-resolution + * units. + * + * Given a high-resolution movement, this function converts the movement into + * microns and emits high-resolution scroll events for the input device. It also + * uses the multiplier from &struct hid_scroll_counter to emit low-resolution + * scroll events when appropriate for backwards-compatibility with userspace + * input libraries. + */ +void hid_scroll_counter_handle_scroll(struct hid_scroll_counter *counter, + int hi_res_value) +{ + int low_res_scroll_amount; + /* Some wheels will rest 7/8ths of a notch from the previous notch + * after slow movement, so we want the threshold for low-res events to + * be in the middle of the notches (e.g. after 4/8ths) as opposed to on + * the notches themselves (8/8ths). + */ + int threshold = counter->resolution_multiplier / 2; + + input_report_rel(counter->dev, REL_WHEEL_HI_RES, + hi_res_value * counter->microns_per_hi_res_unit); + + counter->remainder += hi_res_value; + if (abs(counter->remainder) >= threshold) { + /* Add (or subtract) 1 because we want to trigger when the wheel + * is half-way to the next notch (i.e. scroll 1 notch after a + * 1/2 notch movement, 2 notches after a 1 1/2 notch movement, + * etc.). + */ + low_res_scroll_amount = + counter->remainder / counter->resolution_multiplier + + (hi_res_value > 0 ? 1 : -1); + input_report_rel(counter->dev, REL_WHEEL, + low_res_scroll_amount); + counter->remainder -= + low_res_scroll_amount * counter->resolution_multiplier; + } +} +EXPORT_SYMBOL_GPL(hid_scroll_counter_handle_scroll); diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c index 19cc980eebce..f01280898b24 100644 --- a/drivers/hid/hid-logitech-hidpp.c +++ b/drivers/hid/hid-logitech-hidpp.c @@ -64,6 +64,14 @@ MODULE_PARM_DESC(disable_tap_to_click, #define HIDPP_QUIRK_NO_HIDINPUT BIT(23) #define HIDPP_QUIRK_FORCE_OUTPUT_REPORTS BIT(24) #define HIDPP_QUIRK_UNIFYING BIT(25) +#define HIDPP_QUIRK_HI_RES_SCROLL_1P0 BIT(26) +#define HIDPP_QUIRK_HI_RES_SCROLL_X2120 BIT(27) +#define HIDPP_QUIRK_HI_RES_SCROLL_X2121 BIT(28) + +/* Convenience constant to check for any high-res support. */ +#define HIDPP_QUIRK_HI_RES_SCROLL (HIDPP_QUIRK_HI_RES_SCROLL_1P0 | \ + HIDPP_QUIRK_HI_RES_SCROLL_X2120 | \ + HIDPP_QUIRK_HI_RES_SCROLL_X2121) #define HIDPP_QUIRK_DELAYED_INIT HIDPP_QUIRK_NO_HIDINPUT @@ -149,6 +157,7 @@ struct hidpp_device { unsigned long capabilities; struct hidpp_battery battery; + struct hid_scroll_counter vertical_wheel_counter; }; /* HID++ 1.0 error codes */ @@ -400,32 +409,53 @@ static void hidpp_prefix_name(char **name, int name_length) #define HIDPP_SET_LONG_REGISTER 0x82 #define HIDPP_GET_LONG_REGISTER 0x83 -#define HIDPP_REG_GENERAL 0x00 - -static int hidpp10_enable_battery_reporting(struct hidpp_device *hidpp_dev) +/** + * hidpp10_set_register_bit() - Sets a single bit in a HID++ 1.0 register. + * @hidpp_dev: the device to set the register on. + * @register_address: the address of the register to modify. + * @byte: the byte of the register to modify. Should be less than 3. + * Return: 0 if successful, otherwise a negative error code. + */ +static int hidpp10_set_register_bit(struct hidpp_device *hidpp_dev, + u8 register_address, u8 byte, u8 bit) { struct hidpp_report response; int ret; u8 params[3] = { 0 }; ret = hidpp_send_rap_command_sync(hidpp_dev, - REPORT_ID_HIDPP_SHORT, - HIDPP_GET_REGISTER, - HIDPP_REG_GENERAL, - NULL, 0, &response); + REPORT_ID_HIDPP_SHORT, + HIDPP_GET_REGISTER, + register_address, + NULL, 0, &response); if (ret) return ret; memcpy(params, response.rap.params, 3); - /* Set the battery bit */ - params[0] |= BIT(4); + params[byte] |= BIT(bit); return hidpp_send_rap_command_sync(hidpp_dev, - REPORT_ID_HIDPP_SHORT, - HIDPP_SET_REGISTER, - HIDPP_REG_GENERAL, - params, 3, &response); + REPORT_ID_HIDPP_SHORT, + HIDPP_SET_REGISTER, + register_address, + params, 3, &response); +} + + +#define HIDPP_REG_GENERAL 0x00 + +static int hidpp10_enable_battery_reporting(struct hidpp_device *hidpp_dev) +{ + return hidpp10_set_register_bit(hidpp_dev, HIDPP_REG_GENERAL, 0, 4); +} + +#define HIDPP_REG_FEATURES 0x01 + +/* On HID++ 1.0 devices, high-res scroll was called "scrolling acceleration". */ +static int hidpp10_enable_scrolling_acceleration(struct hidpp_device *hidpp_dev) +{ + return hidpp10_set_register_bit(hidpp_dev, HIDPP_REG_FEATURES, 0, 6); } #define HIDPP_REG_BATTERY_STATUS 0x07 @@ -1136,6 +1166,100 @@ static int hidpp_battery_get_property(struct power_supply *psy, return ret; } +/* -------------------------------------------------------------------------- */ +/* 0x2120: Hi-resolution scrolling */ +/* -------------------------------------------------------------------------- */ + +#define HIDPP_PAGE_HI_RESOLUTION_SCROLLING 0x2120 + +#define CMD_HI_RESOLUTION_SCROLLING_SET_HIGHRES_SCROLLING_MODE 0x10 + +static int hidpp_hrs_set_highres_scrolling_mode(struct hidpp_device *hidpp, + bool enabled, u8 *multiplier) +{ + u8 feature_index; + u8 feature_type; + int ret; + u8 params[1]; + struct hidpp_report response; + + ret = hidpp_root_get_feature(hidpp, + HIDPP_PAGE_HI_RESOLUTION_SCROLLING, + &feature_index, + &feature_type); + if (ret) + return ret; + + params[0] = enabled ? BIT(0) : 0; + ret = hidpp_send_fap_command_sync(hidpp, feature_index, + CMD_HI_RESOLUTION_SCROLLING_SET_HIGHRES_SCROLLING_MODE, + params, sizeof(params), &response); + if (ret) + return ret; + *multiplier = response.fap.params[1]; + return 0; +} + +/* -------------------------------------------------------------------------- */ +/* 0x2121: HiRes Wheel */ +/* -------------------------------------------------------------------------- */ + +#define HIDPP_PAGE_HIRES_WHEEL 0x2121 + +#define CMD_HIRES_WHEEL_GET_WHEEL_CAPABILITY 0x00 +#define CMD_HIRES_WHEEL_SET_WHEEL_MODE 0x20 + +static int hidpp_hrw_get_wheel_capability(struct hidpp_device *hidpp, + u8 *multiplier) +{ + u8 feature_index; + u8 feature_type; + int ret; + struct hidpp_report response; + + ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_HIRES_WHEEL, + &feature_index, &feature_type); + if (ret) + goto return_default; + + ret = hidpp_send_fap_command_sync(hidpp, feature_index, + CMD_HIRES_WHEEL_GET_WHEEL_CAPABILITY, + NULL, 0, &response); + if (ret) + goto return_default; + + *multiplier = response.fap.params[0]; + return 0; +return_default: + hid_warn(hidpp->hid_dev, + "Couldn't get wheel multiplier (error %d), assuming %d.\n", + ret, *multiplier); + return ret; +} + +static int hidpp_hrw_set_wheel_mode(struct hidpp_device *hidpp, bool invert, + bool high_resolution, bool use_hidpp) +{ + u8 feature_index; + u8 feature_type; + int ret; + u8 params[1]; + struct hidpp_report response; + + ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_HIRES_WHEEL, + &feature_index, &feature_type); + if (ret) + return ret; + + params[0] = (invert ? BIT(2) : 0) | + (high_resolution ? BIT(1) : 0) | + (use_hidpp ? BIT(0) : 0); + + return hidpp_send_fap_command_sync(hidpp, feature_index, + CMD_HIRES_WHEEL_SET_WHEEL_MODE, + params, sizeof(params), &response); +} + /* -------------------------------------------------------------------------- */ /* 0x4301: Solar Keyboard */ /* -------------------------------------------------------------------------- */ @@ -2399,7 +2523,8 @@ static int m560_raw_event(struct hid_device *hdev, u8 *data, int size) input_report_rel(mydata->input, REL_Y, v); v = hid_snto32(data[6], 8); - input_report_rel(mydata->input, REL_WHEEL, v); + hid_scroll_counter_handle_scroll( + &hidpp->vertical_wheel_counter, v); input_sync(mydata->input); } @@ -2527,6 +2652,72 @@ static int g920_get_config(struct hidpp_device *hidpp) return 0; } +/* -------------------------------------------------------------------------- */ +/* High-resolution scroll wheels */ +/* -------------------------------------------------------------------------- */ + +/** + * struct hi_res_scroll_info - Stores info on a device's high-res scroll wheel. + * @product_id: the HID product ID of the device being described. + * @microns_per_hi_res_unit: the distance moved by the user's finger for each + * high-resolution unit reported by the device, in + * 256ths of a millimetre. + */ +struct hi_res_scroll_info { + __u32 product_id; + int microns_per_hi_res_unit; +}; + +static struct hi_res_scroll_info hi_res_scroll_devices[] = { + { /* Anywhere MX */ + .product_id = 0x1017, .microns_per_hi_res_unit = 445 }, + { /* Performance MX */ + .product_id = 0x101a, .microns_per_hi_res_unit = 406 }, + { /* M560 */ + .product_id = 0x402d, .microns_per_hi_res_unit = 435 }, + { /* MX Master 2S */ + .product_id = 0x4069, .microns_per_hi_res_unit = 406 }, +}; + +static int hi_res_scroll_look_up_microns(__u32 product_id) +{ + int i; + int num_devices = sizeof(hi_res_scroll_devices) + / sizeof(hi_res_scroll_devices[0]); + for (i = 0; i < num_devices; i++) { + if (hi_res_scroll_devices[i].product_id == product_id) + return hi_res_scroll_devices[i].microns_per_hi_res_unit; + } + /* We don't have a value for this device, so use a sensible default. */ + return 406; +} + +static int hi_res_scroll_enable(struct hidpp_device *hidpp) +{ + int ret; + u8 multiplier = 8; + + if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_X2121) { + ret = hidpp_hrw_set_wheel_mode(hidpp, false, true, false); + hidpp_hrw_get_wheel_capability(hidpp, &multiplier); + } else if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_X2120) { + ret = hidpp_hrs_set_highres_scrolling_mode(hidpp, true, + &multiplier); + } else /* if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_1P0) */ + ret = hidpp10_enable_scrolling_acceleration(hidpp); + + if (ret) + return ret; + + hidpp->vertical_wheel_counter.resolution_multiplier = multiplier; + hidpp->vertical_wheel_counter.microns_per_hi_res_unit = + hi_res_scroll_look_up_microns(hidpp->hid_dev->product); + hid_info(hidpp->hid_dev, "multiplier = %d, microns = %d\n", + multiplier, + hidpp->vertical_wheel_counter.microns_per_hi_res_unit); + return 0; +} + /* -------------------------------------------------------------------------- */ /* Generic HID++ devices */ /* -------------------------------------------------------------------------- */ @@ -2572,6 +2763,11 @@ static void hidpp_populate_input(struct hidpp_device *hidpp, wtp_populate_input(hidpp, input, origin_is_hid_core); else if (hidpp->quirks & HIDPP_QUIRK_CLASS_M560) m560_populate_input(hidpp, input, origin_is_hid_core); + + if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL) { + input_set_capability(input, EV_REL, REL_WHEEL_HI_RES); + hidpp->vertical_wheel_counter.dev = input; + } } static int hidpp_input_configured(struct hid_device *hdev, @@ -2690,6 +2886,27 @@ static int hidpp_raw_event(struct hid_device *hdev, struct hid_report *report, return 0; } +static int hidpp_event(struct hid_device *hdev, struct hid_field *field, + struct hid_usage *usage, __s32 value) +{ + /* This function will only be called for scroll events, due to the + * restriction imposed in hidpp_usages. + */ + struct hidpp_device *hidpp = hid_get_drvdata(hdev); + struct hid_scroll_counter *counter = &hidpp->vertical_wheel_counter; + /* A scroll event may occur before the multiplier has been retrieved or + * the input device set, or high-res scroll enabling may fail. In such + * cases we must return early (falling back to default behaviour) to + * avoid a crash in hid_scroll_counter_handle_scroll. + */ + if (!(hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL) || value == 0 + || counter->dev == NULL || counter->resolution_multiplier == 0) + return 0; + + hid_scroll_counter_handle_scroll(counter, value); + return 1; +} + static int hidpp_initialize_battery(struct hidpp_device *hidpp) { static atomic_t battery_no = ATOMIC_INIT(0); @@ -2901,6 +3118,9 @@ static void hidpp_connect_event(struct hidpp_device *hidpp) if (hidpp->battery.ps) power_supply_changed(hidpp->battery.ps); + if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL) + hi_res_scroll_enable(hidpp); + if (!(hidpp->quirks & HIDPP_QUIRK_NO_HIDINPUT) || hidpp->delayed_input) /* if the input nodes are already created, we can stop now */ return; @@ -3086,35 +3306,63 @@ static void hidpp_remove(struct hid_device *hdev) mutex_destroy(&hidpp->send_mutex); } +#define LDJ_DEVICE(product) \ + HID_DEVICE(BUS_USB, HID_GROUP_LOGITECH_DJ_DEVICE, \ + USB_VENDOR_ID_LOGITECH, (product)) + static const struct hid_device_id hidpp_devices[] = { { /* wireless touchpad */ - HID_DEVICE(BUS_USB, HID_GROUP_LOGITECH_DJ_DEVICE, - USB_VENDOR_ID_LOGITECH, 0x4011), + LDJ_DEVICE(0x4011), .driver_data = HIDPP_QUIRK_CLASS_WTP | HIDPP_QUIRK_DELAYED_INIT | HIDPP_QUIRK_WTP_PHYSICAL_BUTTONS }, { /* wireless touchpad T650 */ - HID_DEVICE(BUS_USB, HID_GROUP_LOGITECH_DJ_DEVICE, - USB_VENDOR_ID_LOGITECH, 0x4101), + LDJ_DEVICE(0x4101), .driver_data = HIDPP_QUIRK_CLASS_WTP | HIDPP_QUIRK_DELAYED_INIT }, { /* wireless touchpad T651 */ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_LOGITECH_T651), .driver_data = HIDPP_QUIRK_CLASS_WTP }, + { /* Mouse Logitech Anywhere MX */ + LDJ_DEVICE(0x1017), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_1P0 }, + { /* Mouse Logitech Cube */ + LDJ_DEVICE(0x4010), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2120 }, + { /* Mouse Logitech M335 */ + LDJ_DEVICE(0x4050), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { /* Mouse Logitech M515 */ + LDJ_DEVICE(0x4007), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2120 }, { /* Mouse logitech M560 */ - HID_DEVICE(BUS_USB, HID_GROUP_LOGITECH_DJ_DEVICE, - USB_VENDOR_ID_LOGITECH, 0x402d), - .driver_data = HIDPP_QUIRK_DELAYED_INIT | HIDPP_QUIRK_CLASS_M560 }, + LDJ_DEVICE(0x402d), + .driver_data = HIDPP_QUIRK_DELAYED_INIT | HIDPP_QUIRK_CLASS_M560 + | HIDPP_QUIRK_HI_RES_SCROLL_X2120 }, + { /* Mouse Logitech M705 (firmware RQM17) */ + LDJ_DEVICE(0x101b), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_1P0 }, + { /* Mouse Logitech M705 (firmware RQM67) */ + LDJ_DEVICE(0x406d), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { /* Mouse Logitech M720 */ + LDJ_DEVICE(0x405e), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { /* Mouse Logitech MX Anywhere 2 */ + LDJ_DEVICE(0x404a), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { LDJ_DEVICE(0xb013), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { LDJ_DEVICE(0xb018), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { LDJ_DEVICE(0xb01f), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { /* Mouse Logitech MX Anywhere 2S */ + LDJ_DEVICE(0x406a), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { /* Mouse Logitech MX Master */ + LDJ_DEVICE(0x4041), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { LDJ_DEVICE(0x4060), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { LDJ_DEVICE(0x4071), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { /* Mouse Logitech MX Master 2S */ + LDJ_DEVICE(0x4069), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_X2121 }, + { /* Mouse Logitech Performance MX */ + LDJ_DEVICE(0x101a), .driver_data = HIDPP_QUIRK_HI_RES_SCROLL_1P0 }, { /* Keyboard logitech K400 */ - HID_DEVICE(BUS_USB, HID_GROUP_LOGITECH_DJ_DEVICE, - USB_VENDOR_ID_LOGITECH, 0x4024), + LDJ_DEVICE(0x4024), .driver_data = HIDPP_QUIRK_CLASS_K400 }, { /* Solar Keyboard Logitech K750 */ - HID_DEVICE(BUS_USB, HID_GROUP_LOGITECH_DJ_DEVICE, - USB_VENDOR_ID_LOGITECH, 0x4002), + LDJ_DEVICE(0x4002), .driver_data = HIDPP_QUIRK_CLASS_K750 }, - { HID_DEVICE(BUS_USB, HID_GROUP_LOGITECH_DJ_DEVICE, - USB_VENDOR_ID_LOGITECH, HID_ANY_ID)}, + { LDJ_DEVICE(HID_ANY_ID) }, { HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_LOGITECH_G920_WHEEL), .driver_data = HIDPP_QUIRK_CLASS_G920 | HIDPP_QUIRK_FORCE_OUTPUT_REPORTS}, @@ -3123,12 +3371,19 @@ static const struct hid_device_id hidpp_devices[] = { MODULE_DEVICE_TABLE(hid, hidpp_devices); +static const struct hid_usage_id hidpp_usages[] = { + { HID_GD_WHEEL, EV_REL, REL_WHEEL }, + { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1} +}; + static struct hid_driver hidpp_driver = { .name = "logitech-hidpp-device", .id_table = hidpp_devices, .probe = hidpp_probe, .remove = hidpp_remove, .raw_event = hidpp_raw_event, + .usage_table = hidpp_usages, + .event = hidpp_event, .input_configured = hidpp_input_configured, .input_mapping = hidpp_input_mapping, .input_mapped = hidpp_input_mapped, diff --git a/include/linux/hid.h b/include/linux/hid.h index d44a78362942..2827b87590d8 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -1139,6 +1139,34 @@ static inline u32 hid_report_len(struct hid_report *report) int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size, int interrupt); + +/** + * struct hid_scroll_counter - Utility class for processing high-resolution + * scroll events. + * @dev: the input device for which events should be reported. + * @microns_per_hi_res_unit: the amount moved by the user's finger for each + * high-resolution unit reported by the mouse, in + * microns. + * @resolution_multiplier: the wheel's resolution in high-resolution mode as a + * multiple of its lower resolution. For example, if + * moving the wheel by one "notch" would result in a + * value of 1 in low-resolution mode but 8 in + * high-resolution, the multiplier is 8. + * @remainder: counts the number of high-resolution units moved since the last + * low-resolution event (REL_WHEEL or REL_HWHEEL) was sent. Should + * only be used by class methods. + */ +struct hid_scroll_counter { + struct input_dev *dev; + int microns_per_hi_res_unit; + int resolution_multiplier; + + int remainder; +}; + +void hid_scroll_counter_handle_scroll(struct hid_scroll_counter *counter, + int hi_res_value); + /* HID quirks API */ unsigned long hid_lookup_quirk(const struct hid_device *hdev); int hid_quirks_init(char **quirks_param, __u16 bus, int count); diff --git a/include/uapi/linux/input-event-codes.h b/include/uapi/linux/input-event-codes.h index 53fbae27b280..6d180cc60a5d 100644 --- a/include/uapi/linux/input-event-codes.h +++ b/include/uapi/linux/input-event-codes.h @@ -708,6 +708,15 @@ #define REL_DIAL 0x07 #define REL_WHEEL 0x08 #define REL_MISC 0x09 +/* + * 0x0a is reserved and should not be used in input drivers. + * It was used by HID as REL_MISC+1 and userspace needs to detect if + * the next REL_* event is correct or is just REL_MISC + n. + * We define here REL_RESERVED so userspace can rely on it and detect + * the situation described above. + */ +#define REL_RESERVED 0x0a +#define REL_WHEEL_HI_RES 0x0b #define REL_MAX 0x0f #define REL_CNT (REL_MAX+1) @@ -744,6 +753,15 @@ #define ABS_MISC 0x28 +/* + * 0x2e is reserved and should not be used in input drivers. + * It was used by HID as ABS_MISC+6 and userspace needs to detect if + * the next ABS_* event is correct or is just ABS_MISC + n. + * We define here ABS_RESERVED so userspace can rely on it and detect + * the situation described above. + */ +#define ABS_RESERVED 0x2e + #define ABS_MT_SLOT 0x2f /* MT slot being modified */ #define ABS_MT_TOUCH_MAJOR 0x30 /* Major axis of touching ellipse */ #define ABS_MT_TOUCH_MINOR 0x31 /* Minor axis (omit if circular) */