[PATCH 8/8] HID: logitech: Enable high-resolution scrolling on Logitech mice

From: Peter Hutterer
Date: Thu Nov 22 2018 - 01:35:20 EST


From: Harry Cutts <hcutts@xxxxxxxxxxxx>

There are three features used by various Logitech mice for
high-resolution scrolling: the scrolling acceleration bit in HID++ 1.0,
and the x2120 and x2121 features in HID++ 2.0 and above. This patch
supports all three, and uses the multiplier reported by the mouse for
the HID++ 2.0+ features.

The full list of product IDs of mice which support high-resolution
scrolling was provided by Logitech, but the patch was tested using the
following mice (using the Unifying receiver):

* HID++ 1.0: Anywhere MX, Performance MX
* x2120: M560
* x2121: MX Anywhere 2, MX Master 2S

This patch is a combinations of the now-reverted commits 1ff2e1a44e0,
d56ca9855bf9, 5fe2ccbef9d, 044ee89028 together with some extra bits for the
directional and timeout-based reset.
The previous patch series was in hid-input, it appears this remainder
handling is logitech-specific and was moved to hid-logitech-hidpp.c and
renamed accordingly.

Signed-off-by: Harry Cutts <hcutts@xxxxxxxxxxxx>
Signed-off-by: Peter Hutterer <peter.hutterer@xxxxxxxxx>
---
Changes to the previous version:
- this is a squash of the commits above, splitting it up after all the
changes was a tad difficult
- this looks to be a logitech-specific requirement because the firmware
can swallow events. I moved the lot to the hidpp implementation
- added directional reset together with the threshold-based REL_WHEEL
emulation trigger
- added a timeout to stop the emulation from sliding too much within the
window

This was tested on an MX Anywhere 2S, Harry, please re-test on the other
mice, thanks.

drivers/hid/hid-logitech-hidpp.c | 310 ++++++++++++++++++++++++++++++-
1 file changed, 306 insertions(+), 4 deletions(-)

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 67ca587aecfa..8d2a7000bf0c 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -21,6 +21,7 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sched.h>
+#include <linux/timer.h>
#include <linux/kfifo.h>
#include <linux/input/mt.h>
#include <linux/workqueue.h>
@@ -64,6 +65,14 @@ 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

@@ -128,6 +137,31 @@ struct hidpp_battery {
bool online;
};

+/**
+ * struct hidpp_scroll_counter - Utility class for processing high-resolution
+ * scroll events.
+ * @dev: the input device for which events should be reported.
+ * @wheel_multiplier: the scalar multiplier to be applied to wheel
+ * data as a fraction of 120. For example, if
+ * moving the wheel by one detent would result in a
+ * value of 1 in low-resolution mode but 8 in
+ * high-resolution, the multiplier is 120/8.
+ * @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.
+ * @direction: direction of last movement (1 or -1)
+ * @time: the timer to reset the remainder after a period of inactivity
+ */
+struct hidpp_scroll_counter {
+ struct input_dev *dev;
+ int wheel_multiplier;
+
+ int remainder;
+ int direction;
+
+ struct timer_list timer;
+};
+
struct hidpp_device {
struct hid_device *hid_dev;
struct mutex send_mutex;
@@ -149,6 +183,7 @@ struct hidpp_device {
unsigned long capabilities;

struct hidpp_battery battery;
+ struct hidpp_scroll_counter vertical_wheel_counter;
};

/* HID++ 1.0 error codes */
@@ -391,6 +426,65 @@ static void hidpp_prefix_name(char **name, int name_length)
*name = new_name;
}

+/**
+ * hidpp_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
+ * fractions of 120 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.
+ */
+static void hidpp_scroll_counter_handle_scroll(struct hidpp_scroll_counter *counter,
+ int hi_res_value)
+{
+ int low_res_value, remainder, direction;
+
+ hi_res_value *= counter->wheel_multiplier;
+ input_report_rel(counter->dev, REL_WHEEL_HI_RES, hi_res_value);
+
+ /*
+ * Update the low-res remainder with the high-res value,
+ * but reset if the direction has changed.
+ */
+ remainder = counter->remainder;
+ direction = hi_res_value > 0 ? 1 : -1;
+ if (direction != counter->direction)
+ remainder = 0;
+ counter->direction = direction;
+ remainder += hi_res_value;
+
+ /* Some wheels will rest 7/8ths of a detent from the previous detent
+ * after slow movement, so we want the threshold for low-res events to
+ * be in the middle between two detents (e.g. after 4/8ths) as
+ * opposed to on the detents themselves (8/8ths).
+ */
+ if (abs(remainder) >= 60) {
+ /* Add (or subtract) 1 because we want to trigger when the wheel
+ * is half-way to the next detent (i.e. scroll 1 detent after a
+ * 1/2 detent movement, 2 detents after a 1 1/2 detent movement,
+ * etc.).
+ */
+ low_res_value = remainder / 120;
+ if (low_res_value == 0)
+ low_res_value = (hi_res_value > 0 ? 1 : -1);
+ input_report_rel(counter->dev, REL_WHEEL, low_res_value);
+ remainder -= low_res_value * 120;
+ }
+ counter->remainder = remainder;
+
+ /*
+ * Even with the above, our emulation point still slides around with
+ * some movements. Reset it after a second of no activity.
+ */
+ mod_timer(&counter->timer, jiffies + msecs_to_jiffies(1000));
+}
+
/* -------------------------------------------------------------------------- */
/* HIDP++ 1.0 commands */
/* -------------------------------------------------------------------------- */
@@ -1157,6 +1251,99 @@ 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)\n", ret);
+ 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 */
/* -------------------------------------------------------------------------- */
@@ -2420,7 +2607,8 @@ 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);
+ hidpp_scroll_counter_handle_scroll(
+ &hidpp->vertical_wheel_counter, v);

input_sync(mydata->input);
}
@@ -2548,6 +2736,37 @@ static int g920_get_config(struct hidpp_device *hidpp)
return 0;
}

+/* -------------------------------------------------------------------------- */
+/* High-resolution scroll wheels */
+/* -------------------------------------------------------------------------- */
+
+static int hi_res_scroll_enable(struct hidpp_device *hidpp)
+{
+ int ret;
+ u8 multiplier = 1;
+
+ if (hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL_X2121) {
+ ret = hidpp_hrw_set_wheel_mode(hidpp, false, true, false);
+ if (ret == 0)
+ ret = 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);
+ multiplier = 8;
+ }
+ if (ret)
+ return ret;
+
+ if (multiplier == 0)
+ multiplier = 120;
+
+ hidpp->vertical_wheel_counter.wheel_multiplier = 120/multiplier;
+ hid_info(hidpp->hid_dev, "multiplier = %d\n", multiplier);
+ return 0;
+}
+
/* -------------------------------------------------------------------------- */
/* Generic HID++ devices */
/* -------------------------------------------------------------------------- */
@@ -2593,6 +2812,11 @@ 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,
@@ -2711,6 +2935,27 @@ 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 hidpp_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 hidpp_scroll_counter_handle_scroll.
+ */
+ if (!(hidpp->quirks & HIDPP_QUIRK_HI_RES_SCROLL) || value == 0
+ || counter->dev == NULL || counter->wheel_multiplier == 0)
+ return 0;
+
+ hidpp_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);
@@ -2922,6 +3167,9 @@ 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;
@@ -2952,6 +3200,15 @@ static const struct attribute_group ps_attribute_group = {
.attrs = sysfs_attrs
};

+
+
+static void hidpp_scroll_timeout(struct timer_list *t)
+{
+ struct hidpp_scroll_counter *counter = from_timer(counter, t,
+ timer);
+ counter->remainder = 0;
+}
+
static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
struct hidpp_device *hidpp;
@@ -2992,6 +3249,9 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
goto allocate_fail;
}

+ timer_setup(&hidpp->vertical_wheel_counter.timer,
+ hidpp_scroll_timeout, 0);
+
INIT_WORK(&hidpp->work, delayed_work_cb);
mutex_init(&hidpp->send_mutex);
init_waitqueue_head(&hidpp->wait);
@@ -3096,6 +3356,8 @@ static void hidpp_remove(struct hid_device *hdev)
{
struct hidpp_device *hidpp = hid_get_drvdata(hdev);

+ del_timer_sync(&hidpp->vertical_wheel_counter.timer);
+
sysfs_remove_group(&hdev->dev.kobj, &ps_attribute_group);

if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) {
@@ -3107,6 +3369,10 @@ 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 */
LDJ_DEVICE(0x4011),
@@ -3119,10 +3385,39 @@ static const struct hid_device_id hidpp_devices[] = {
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 */
LDJ_DEVICE(0x4024),
.driver_data = HIDPP_QUIRK_CLASS_K400 },
@@ -3139,12 +3434,19 @@ 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_HI_RES },
+ { 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,
--
2.19.1