[PATCH 2/2] HID: Force feedback support for the Logitech G920

From: Edwin Velds
Date: Sat Nov 21 2015 - 07:38:00 EST

This patch implements force feedback support for the Logitech
G920 Driving Force Racing Wheel. It is a generic implementation
of feature 0x8123 of the Logitech HID++ protocol and should be
usable for any future devices that implement this feature.

The driving supports everything that is supported by the G920
firmware:
FF_CONSTANT
FF_PERIODIC
FF_SINE
FF_SQUARE
FF_SAW_UP
FF_SAW_DOWN
FF_TRIANGLE
FF_SPRING
FF_DAMPER
FF_AUTOCENTER
FF_GAIN

Both envelopes and replay values are supported as well.

Note that the G920 (like previous Logitech wheels) starts with
a heavy default spring enabled. Unlike previous wheels, there
is no command to disable this spring and it will only release
when other forces are downloaded into the device.

Signed-off-by: Edwin Velds <e.velds@xxxxxxxxx>
---
drivers/hid/Makefile | 2 +-
drivers/hid/hid-logitech-hidpp-base.c | 114 +------
drivers/hid/hid-logitech-hidpp-ff.c | 540 ++++++++++++++++++++++++++++++++++
drivers/hid/hid-logitech-hidpp-ff.h | 9 +
4 files changed, 554 insertions(+), 111 deletions(-)
create mode 100644 drivers/hid/hid-logitech-hidpp-ff.c
create mode 100644 drivers/hid/hid-logitech-hidpp-ff.h

diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index a01c448..fd49428 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -17,7 +17,7 @@ hid-logitech-$(CONFIG_LOGIRUMBLEPAD2_FF) += hid-lg2ff.o
hid-logitech-$(CONFIG_LOGIG940_FF) += hid-lg3ff.o
hid-logitech-$(CONFIG_LOGIWHEELS_FF) += hid-lg4ff.o

-hid-logitech-hidpp-y := hid-logitech-hidpp-base.o
+hid-logitech-hidpp-y := hid-logitech-hidpp-base.o hid-logitech-hidpp-ff.o

hid-wiimote-y := hid-wiimote-core.o hid-wiimote-modules.o
hid-wiimote-$(CONFIG_DEBUG_FS) += hid-wiimote-debug.o
diff --git a/drivers/hid/hid-logitech-hidpp-base.c b/drivers/hid/hid-logitech-hidpp-base.c
index 40ab079..9b6d82a 100644
--- a/drivers/hid/hid-logitech-hidpp-base.c
+++ b/drivers/hid/hid-logitech-hidpp-base.c
@@ -22,6 +22,7 @@
#include <asm/unaligned.h>
#include "hid-ids.h"
#include "hid-logitech-hidpp-base.h"
+#include "hid-logitech-hidpp-ff.h"

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@xxxxxxxxx>");
@@ -1232,123 +1233,21 @@ static int k400_connect(struct hid_device *hdev, bool connected)

#define HIDPP_PAGE_G920_FORCE_FEEDBACK 0x8123

-/* Using session ID = 1 */
-#define CMD_G920_FORCE_GET_APERTURE 0x51
-#define CMD_G920_FORCE_SET_APERTURE 0x61
-
-struct g920_private_data {
- u8 force_feature;
- u16 range;
-};
-
-#define to_hid_device(pdev) container_of(pdev, struct hid_device, dev)
-
-static ssize_t g920_range_show(struct device *dev, struct device_attribute *attr,
- char *buf)
-{
- struct hid_device *hid = to_hid_device(dev);
- struct hidpp_device *hidpp = hid_get_drvdata(hid);
- struct g920_private_data *pdata;
-
- pdata = hidpp->private_data;
- if (!pdata) {
- hid_err(hid, "Private driver data not found!\n");
- return -EINVAL;
- }
-
- return scnprintf(buf, PAGE_SIZE, "%u\n", pdata->range);
-}
-
-static ssize_t g920_range_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct hid_device *hid = to_hid_device(dev);
- struct hidpp_device *hidpp = hid_get_drvdata(hid);
- struct g920_private_data *pdata;
- struct hidpp_report response;
- u8 params[2];
- int ret;
- u16 range = simple_strtoul(buf, NULL, 10);
-
- pdata = hidpp->private_data;
- if (!pdata) {
- hid_err(hid, "Private driver data not found!\n");
- return -EINVAL;
- }
-
- if (range < 180)
- range = 180;
- else if (range > 900)
- range = 900;
-
- params[0] = range >> 8;
- params[1] = range & 0x00FF;
-
- ret = hidpp_send_fap_command_sync(hidpp, pdata->force_feature,
- CMD_G920_FORCE_SET_APERTURE, params, 2, &response);
- if (ret)
- return ret;
-
- pdata->range = range;
- return count;
-}
-
-static DEVICE_ATTR(range, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, g920_range_show, g920_range_store);
-
-static int g920_allocate(struct hid_device *hdev)
-{
- struct hidpp_device *hidpp = hid_get_drvdata(hdev);
- struct g920_private_data *pdata;
-
- pdata = devm_kzalloc(&hdev->dev, sizeof(struct g920_private_data),
- GFP_KERNEL);
- if (!pdata)
- return -ENOMEM;
-
- hidpp->private_data = pdata;
-
- return 0;
-}
-
static int g920_get_config(struct hidpp_device *hidpp)
{
- struct g920_private_data *pdata = hidpp->private_data;
- struct hidpp_report response;
u8 feature_type;
u8 feature_index;
int ret;

- pdata = hidpp->private_data;
- if (!pdata) {
- hid_err(hidpp->hid_dev, "Private driver data not found!\n");
- return -EINVAL;
- }
-
/* Find feature and store for later use */
ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_G920_FORCE_FEEDBACK,
&feature_index, &feature_type);
if (ret)
return ret;

- pdata->force_feature = feature_index;
-
- /* Read current Range */
- ret = hidpp_send_fap_command_sync(hidpp, feature_index,
- CMD_G920_FORCE_GET_APERTURE, NULL, 0, &response);
- if (ret > 0) {
- hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
- __func__, ret);
- return -EPROTO;
- }
+ ret = hidpp_ff_init(hidpp, feature_index);
if (ret)
- return ret;
-
- pdata->range = get_unaligned_be16(&response.fap.params[0]);
-
- /* Create sysfs interface */
- ret = device_create_file(&(hidpp->hid_dev->dev), &dev_attr_range);
- if (ret)
- hid_warn(hidpp->hid_dev, "Unable to create sysfs interface for \"range\", errno %d\n", ret);
+ hid_warn(hidpp->hid_dev, "Unable to initialize force feedback support, errno %d\n", ret);

return 0;
}
@@ -1672,10 +1571,6 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
ret = k400_allocate(hdev);
if (ret)
goto allocate_fail;
- } else if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) {
- ret = g920_allocate(hdev);
- if (ret)
- goto allocate_fail;
}

INIT_WORK(&hidpp->work, delayed_work_cb);
@@ -1758,7 +1653,6 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
hid_hw_open_failed:
hid_device_io_stop(hdev);
if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) {
- device_remove_file(&hdev->dev, &dev_attr_range);
hid_hw_close(hdev);
hid_hw_stop(hdev);
}
@@ -1776,7 +1670,7 @@ static void hidpp_remove(struct hid_device *hdev)
struct hidpp_device *hidpp = hid_get_drvdata(hdev);

if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) {
- device_remove_file(&hdev->dev, &dev_attr_range);
+ hidpp_ff_deinit(hdev);
hid_hw_close(hdev);
}
hid_hw_stop(hdev);
diff --git a/drivers/hid/hid-logitech-hidpp-ff.c b/drivers/hid/hid-logitech-hidpp-ff.c
new file mode 100644
index 0000000..31ae359
--- /dev/null
+++ b/drivers/hid/hid-logitech-hidpp-ff.c
@@ -0,0 +1,540 @@
+/*
+ * Force feedback support for Logitech HID++ devices [feature 0x8123]
+ *
+ * Currently only used for the G920 Driving Force Racing Wheel
+ *
+ * Copyright (c) 2015 Edwin Velds <e.velds@xxxxxxxxx>
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; version 2 of the License.
+ */
+
+#include <linux/device.h>
+#include <linux/input.h>
+#include <linux/workqueue.h>
+#include <asm/unaligned.h>
+#include <linux/atomic.h>
+#include <linux/fixp-arith.h>
+#include "hid-logitech-hidpp-ff.h"
+
+
+#define HIDPP_FF_GET_INFO 0x01
+#define HIDPP_FF_RESET_ALL 0x11
+#define HIDPP_FF_DOWNLOAD_EFFECT 0x21
+#define HIDPP_FF_SET_EFFECT_STATE 0x31
+#define HIDPP_FF_DESTROY_EFFECT 0x41
+#define HIDPP_FF_GET_APERTURE 0x51
+#define HIDPP_FF_SET_APERTURE 0x61
+#define HIDPP_FF_GET_GLOBAL_GAINS 0x71
+#define HIDPP_FF_SET_GLOBAL_GAINS 0x81
+
+#define HIDPP_FF_EFFECT_STATE_GET 0x00
+#define HIDPP_FF_EFFECT_STATE_STOP 0x01
+#define HIDPP_FF_EFFECT_STATE_PLAY 0x02
+#define HIDPP_FF_EFFECT_STATE_PAUSE 0x03
+
+#define HIDPP_FF_EFFECT_CONSTANT 0x00
+#define HIDPP_FF_EFFECT_PERIODIC_SINE 0x01
+#define HIDPP_FF_EFFECT_PERIODIC_SQUARE 0x02
+#define HIDPP_FF_EFFECT_PERIODIC_TRIANGLE 0x03
+#define HIDPP_FF_EFFECT_PERIODIC_SAWTOOTHUP 0x04
+#define HIDPP_FF_EFFECT_PERIODIC_SAWTOOTHDOWN 0x05
+#define HIDPP_FF_EFFECT_SPRING 0x06
+#define HIDPP_FF_EFFECT_DAMPER 0x07
+
+#define HIDPP_FF_EFFECT_AUTOSTART 0x80
+
+#define HIDPP_FF_EFFECTID_NONE -1
+#define HIDPP_FF_EFFECTID_AUTOCENTER -2
+
+#define HIDPP_FF_MAX_PARAMS 20
+
+#define to_hid_device(pdev) container_of(pdev, struct hid_device, dev)
+
+
+struct hidpp_ff_private_data {
+ struct hidpp_device *hidpp;
+ u8 feature_index;
+ u16 gain;
+ s16 range;
+ u8 slot_autocenter;
+ u8 num_effects;
+ int *effect_ids;
+ struct workqueue_struct *wq;
+ atomic_t workqueue_size;
+};
+
+struct hidpp_ff_work_data {
+ struct work_struct work;
+ struct hidpp_ff_private_data *data;
+ int effect_id;
+ u8 command;
+ u8 params[HIDPP_FF_MAX_PARAMS];
+ u8 size;
+};
+
+static const signed short hiddpp_ff_effects[] = {
+ FF_CONSTANT,
+ FF_PERIODIC,
+ FF_SINE,
+ FF_SQUARE,
+ FF_SAW_UP,
+ FF_SAW_DOWN,
+ FF_TRIANGLE,
+ FF_SPRING,
+ FF_DAMPER,
+ FF_AUTOCENTER,
+ FF_GAIN,
+ -1
+};
+
+
+static u8 hidpp_ff_find_effect(struct hidpp_ff_private_data *data, int effect_id)
+{
+ int i;
+
+ for (i = 0; i < data->num_effects; i++)
+ if (data->effect_ids[i] == effect_id)
+ return i+1;
+
+ return 0;
+}
+
+static void hidpp_ff_work_handler(struct work_struct *w)
+{
+ struct hidpp_ff_work_data *wd = container_of(w, struct hidpp_ff_work_data, work);
+ struct hidpp_ff_private_data *data = wd->data;
+ struct hidpp_report response;
+ u8 slot;
+ int ret;
+
+ /* add slot number if needed */
+ switch (wd->effect_id) {
+ case HIDPP_FF_EFFECTID_AUTOCENTER:
+ wd->params[0] = data->slot_autocenter;
+ break;
+ case HIDPP_FF_EFFECTID_NONE:
+ /* leave slot as zero */
+ break;
+ default:
+ /* find current slot for effect */
+ wd->params[0] = hidpp_ff_find_effect(data, wd->effect_id);
+ break;
+ }
+
+ /* send command and wait for reply */
+ ret = hidpp_send_fap_command_sync(data->hidpp, data->feature_index,
+ wd->command, wd->params, wd->size, &response);
+
+ if (ret) {
+ hid_err(data->hidpp->hid_dev, "Failed to send command to device!\n");
+ goto out;
+ }
+
+ /* parse return data */
+ switch (wd->command) {
+ case HIDPP_FF_DOWNLOAD_EFFECT:
+ slot = response.fap.params[0];
+ if (slot > 0 && slot <= data->num_effects) {
+ if (wd->effect_id >= 0)
+ /* regular effect uploaded */
+ data->effect_ids[slot-1] = wd->effect_id;
+ else if (wd->effect_id >= HIDPP_FF_EFFECTID_AUTOCENTER)
+ /* autocenter spring uploaded */
+ data->slot_autocenter = slot;
+ }
+ break;
+ case HIDPP_FF_DESTROY_EFFECT:
+ if (wd->effect_id >= 0)
+ /* regular effect destroyed */
+ data->effect_ids[wd->params[0]-1] = -1;
+ else if (wd->effect_id >= HIDPP_FF_EFFECTID_AUTOCENTER)
+ /* autocenter spring destoyed */
+ data->slot_autocenter = 0;
+ break;
+ case HIDPP_FF_SET_GLOBAL_GAINS:
+ data->gain = (wd->params[0] << 8) + wd->params[1];
+ break;
+ case HIDPP_FF_SET_APERTURE:
+ data->range = (wd->params[0] << 8) + wd->params[1];
+ break;
+ default:
+ /* no action needed */
+ break;
+ }
+
+out:
+ atomic_dec(&data->workqueue_size);
+ kfree(wd);
+}
+
+static int hidpp_ff_queue_work(struct hidpp_ff_private_data *data, int effect_id, u8 command, u8 *params, u8 size)
+{
+ struct hidpp_ff_work_data *wd = kzalloc(sizeof(struct hidpp_ff_work_data), GFP_KERNEL);
+ int s;
+
+ if (!wd)
+ return -ENOMEM;
+
+ INIT_WORK(&wd->work, hidpp_ff_work_handler);
+
+ wd->data = data;
+ wd->effect_id = effect_id;
+ wd->command = command;
+ wd->size = size;
+ memcpy(wd->params, params, size);
+
+ atomic_inc(&data->workqueue_size);
+ queue_work(data->wq, &wd->work);
+
+ /* warn about excessive queue size */
+ s = atomic_read(&data->workqueue_size);
+ if (s >= 20 && s % 20 == 0)
+ hid_warn(data->hidpp->hid_dev, "Force feedback command queue contains %d commands, causing substantial delays.", s);
+
+ return 0;
+}
+
+static int hidpp_ff_upload_effect(struct input_dev *dev, struct ff_effect *effect, struct ff_effect *old)
+{
+ struct hidpp_ff_private_data *data = dev->ff->private;
+ u8 params[20];
+ u8 size;
+ int force;
+
+ /* set common parameters */
+ params[2] = effect->replay.length >> 8;
+ params[3] = effect->replay.length & 255;
+ params[4] = effect->replay.delay >> 8;
+ params[5] = effect->replay.delay & 255;
+
+ switch (effect->type) {
+ case FF_CONSTANT:
+ force = (effect->u.constant.level * fixp_sin16((effect->direction * 360) >> 16)) >> 15;
+ params[1] = HIDPP_FF_EFFECT_CONSTANT;
+ params[6] = force >> 8;
+ params[7] = force & 255;
+ params[8] = effect->u.constant.envelope.attack_level >> 8;
+ params[9] = effect->u.constant.envelope.attack_length >> 8;
+ params[10] = effect->u.constant.envelope.attack_length & 255;
+ params[11] = effect->u.constant.envelope.fade_level >> 8;
+ params[12] = effect->u.constant.envelope.fade_length >> 8;
+ params[13] = effect->u.constant.envelope.fade_length & 255;
+ size = 14;
+ dbg_hid("Uploading constant force level=%d in dir %d = %d\n",
+ effect->u.constant.level,
+ effect->direction, force);
+ dbg_hid(" envelope attack=(%d, %d ms) fade=(%d, %d ms)\n",
+ effect->u.constant.envelope.attack_level,
+ effect->u.constant.envelope.attack_length,
+ effect->u.constant.envelope.fade_level,
+ effect->u.constant.envelope.fade_length);
+ break;
+ case FF_PERIODIC:
+ {
+ switch (effect->u.periodic.waveform) {
+ case FF_SINE:
+ params[1] = HIDPP_FF_EFFECT_PERIODIC_SINE;
+ break;
+ case FF_SQUARE:
+ params[1] = HIDPP_FF_EFFECT_PERIODIC_SQUARE;
+ break;
+ case FF_SAW_UP:
+ params[1] = HIDPP_FF_EFFECT_PERIODIC_SAWTOOTHUP;
+ break;
+ case FF_SAW_DOWN:
+ params[1] = HIDPP_FF_EFFECT_PERIODIC_SAWTOOTHDOWN;
+ break;
+ case FF_TRIANGLE:
+ params[1] = HIDPP_FF_EFFECT_PERIODIC_TRIANGLE;
+ break;
+ default:
+ hid_err(data->hidpp->hid_dev, "Unexpected periodic waveform type %i!\n", effect->u.periodic.waveform);
+ return -EINVAL;
+ }
+ force = (effect->u.periodic.magnitude * fixp_sin16((effect->direction * 360) >> 16)) >> 15;
+ params[6] = effect->u.periodic.magnitude >> 8;
+ params[7] = effect->u.periodic.magnitude & 255;
+ params[8] = effect->u.periodic.offset >> 8;
+ params[9] = effect->u.periodic.offset & 255;
+ params[10] = effect->u.periodic.period >> 8;
+ params[11] = effect->u.periodic.period & 255;
+ params[12] = effect->u.periodic.phase >> 8;
+ params[13] = effect->u.periodic.phase & 255;
+ params[14] = effect->u.periodic.envelope.attack_level >> 7;
+ params[15] = effect->u.periodic.envelope.attack_length >> 8;
+ params[16] = effect->u.periodic.envelope.attack_length & 255;
+ params[17] = effect->u.periodic.envelope.fade_level >> 7;
+ params[18] = effect->u.periodic.envelope.fade_length >> 8;
+ params[19] = effect->u.periodic.envelope.fade_length & 255;
+ size = 20;
+ dbg_hid("Uploading periodic force mag=%d/dir=%d, offset=%d, period=%d ms, phase=%d\n",
+ effect->u.periodic.magnitude, effect->direction,
+ effect->u.periodic.offset,
+ effect->u.periodic.period,
+ effect->u.periodic.phase);
+ dbg_hid(" envelope attack=(%d, %d ms) fade=(%d, %d ms)\n",
+ effect->u.periodic.envelope.attack_level,
+ effect->u.periodic.envelope.attack_length,
+ effect->u.periodic.envelope.fade_level,
+ effect->u.periodic.envelope.fade_length);
+ break;
+ }
+ case FF_SPRING:
+ case FF_DAMPER:
+ params[1] = effect->type == FF_SPRING ? HIDPP_FF_EFFECT_SPRING : HIDPP_FF_EFFECT_DAMPER;
+ params[6] = effect->u.condition[0].left_saturation >> 9;
+ params[7] = (effect->u.condition[0].left_saturation >> 1) & 255;
+ params[8] = effect->u.condition[0].left_coeff >> 8;
+ params[9] = effect->u.condition[0].left_coeff & 255;
+ params[10] = effect->u.condition[0].deadband >> 9;
+ params[11] = (effect->u.condition[0].deadband >> 1) & 255;
+ params[12] = effect->u.condition[0].center >> 8;
+ params[13] = effect->u.condition[0].center & 255;
+ params[14] = effect->u.condition[0].right_coeff >> 8;
+ params[15] = effect->u.condition[0].right_coeff & 255;
+ params[16] = effect->u.condition[0].right_saturation >> 9;
+ params[17] = (effect->u.condition[0].right_saturation >> 1) & 255;
+ size = 18;
+ dbg_hid("Uploading %s force left coeff=%d, left sat=%d, right coeff=%d, right sat=%d\n",
+ effect->type == FF_SPRING ? "spring" : "damper",
+ effect->u.condition[0].left_coeff,
+ effect->u.condition[0].left_saturation,
+ effect->u.condition[0].right_coeff,
+ effect->u.condition[0].right_saturation);
+ dbg_hid(" deadband=%d, center=%d\n",
+ effect->u.condition[0].deadband,
+ effect->u.condition[0].center);
+ break;
+ default:
+ hid_err(data->hidpp->hid_dev, "Unexpected force type %i!\n", effect->type);
+ return -EINVAL;
+ }
+
+ return hidpp_ff_queue_work(data, effect->id, HIDPP_FF_DOWNLOAD_EFFECT, params, size);
+}
+
+static int hidpp_ff_playback(struct input_dev *dev, int effect_id, int value)
+{
+ struct hidpp_ff_private_data *data = dev->ff->private;
+ u8 params[2];
+
+ params[1] = value ? HIDPP_FF_EFFECT_STATE_PLAY : HIDPP_FF_EFFECT_STATE_STOP;
+
+ dbg_hid("St%sing playback of effect %d!\n", value?"art":"opp", effect_id);
+
+ return hidpp_ff_queue_work(data, effect_id, HIDPP_FF_SET_EFFECT_STATE, params, 2);
+}
+
+static int hidpp_ff_erase_effect(struct input_dev *dev, int effect_id)
+{
+ struct hidpp_ff_private_data *data = dev->ff->private;
+ u8 slot = 0;
+
+ dbg_hid("Erasing effect %d!\n", effect_id);
+
+ return hidpp_ff_queue_work(data, effect_id, HIDPP_FF_DESTROY_EFFECT, &slot, 1);
+}
+
+static void hidpp_ff_set_autocenter(struct input_dev *dev, u16 magnitude)
+{
+ struct hidpp_ff_private_data *data = dev->ff->private;
+ u8 params[18];
+
+ dbg_hid("Setting autocenter to %d!\n", magnitude);
+
+ if (magnitude) {
+ /* start a standard spring effect */
+ params[1] = HIDPP_FF_EFFECT_SPRING | HIDPP_FF_EFFECT_AUTOSTART;
+ /* zero delay and duration */
+ params[2] = params[3] = params[4] = params[5] = 0;
+ /* saturation and coeff to equal value */
+ params[6] = params[8] = params[14] = params[16] = magnitude >> 9;
+ params[7] = params[9] = params[15] = params[17] = (magnitude & 255) >> 1;
+ /* zero deadband and center */
+ params[10] = params[11] = params[12] = params[13] = 0;
+
+ hidpp_ff_queue_work(data, HIDPP_FF_EFFECTID_AUTOCENTER, HIDPP_FF_DOWNLOAD_EFFECT, params, ARRAY_SIZE(params));
+ } else {
+ if (data->slot_autocenter) {
+ /* remove spring effect */
+ hidpp_ff_queue_work(data, HIDPP_FF_EFFECTID_AUTOCENTER, HIDPP_FF_DESTROY_EFFECT, params, 1);
+ }
+ }
+}
+
+static void hidpp_ff_set_gain(struct input_dev *dev, u16 gain)
+{
+ struct hidpp_ff_private_data *data = dev->ff->private;
+ u8 params[4];
+
+ dbg_hid("Setting gain to %d!\n", gain);
+
+ params[0] = gain >> 8;
+ params[1] = gain & 255;
+ params[2] = 0; /* no boost */
+ params[3] = 0;
+
+ hidpp_ff_queue_work(data, HIDPP_FF_EFFECTID_NONE, HIDPP_FF_SET_GLOBAL_GAINS, params, 4);
+}
+
+static ssize_t hidpp_ff_range_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct hid_device *hid = to_hid_device(dev);
+ struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+ struct input_dev *idev = hidinput->input;
+ struct hidpp_ff_private_data *data = idev->ff->private;
+
+ return scnprintf(buf, PAGE_SIZE, "%u\n", data->range);
+}
+
+static ssize_t hidpp_ff_range_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct hid_device *hid = to_hid_device(dev);
+ struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+ struct input_dev *idev = hidinput->input;
+ struct hidpp_ff_private_data *data = idev->ff->private;
+ u8 params[2];
+ int range = simple_strtoul(buf, NULL, 10);
+
+ range = clamp(range, 180, 900);
+
+ params[0] = range >> 8;
+ params[1] = range & 0x00FF;
+
+ hidpp_ff_queue_work(data, -1, HIDPP_FF_SET_APERTURE, params, 2);
+
+ return count;
+}
+
+static DEVICE_ATTR(range, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, hidpp_ff_range_show, hidpp_ff_range_store);
+
+static void hidpp_ff_destroy(struct ff_device *ff)
+{
+ struct hidpp_ff_private_data *data = ff->private;
+
+ kfree(data->effect_ids);
+}
+
+int hidpp_ff_init(struct hidpp_device *hidpp, u8 feature_index)
+{
+ struct hid_device *hid = hidpp->hid_dev;
+ struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+ struct input_dev *dev = hidinput->input;
+ struct ff_device *ff;
+ struct hidpp_report response;
+ struct hidpp_ff_private_data *data;
+ int error, j, num_slots;
+
+ if (!dev) {
+ hid_err(hid, "Struct input_dev not set!\n");
+ return -EINVAL;
+ }
+
+ /* Set supported force feedback capabilities */
+ for (j = 0; hiddpp_ff_effects[j] >= 0; j++)
+ set_bit(hiddpp_ff_effects[j], dev->ffbit);
+
+ /* Read number of slots available in device */
+ error = hidpp_send_fap_command_sync(hidpp, feature_index,
+ HIDPP_FF_GET_INFO, NULL, 0, &response);
+ if (error) {
+ if (error < 0)
+ return error;
+ hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
+ __func__, error);
+ return -EPROTO;
+ }
+
+ num_slots = response.fap.params[0];
+
+ error = input_ff_create(dev, num_slots);
+
+ if (error) {
+ hid_err(dev, "Failed to create FF device\n");
+ return error;
+ }
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ data->effect_ids = kzalloc(num_slots*sizeof(int), GFP_KERNEL);
+ if (!data->effect_ids) {
+ kfree(data);
+ return -ENOMEM;
+ }
+ data->hidpp = hidpp;
+ data->feature_index = feature_index;
+ data->slot_autocenter = 0;
+ data->num_effects = num_slots;
+ for (j = 0; j < num_slots; j++)
+ data->effect_ids[j] = -1;
+
+ ff = dev->ff;
+ ff->private = data;
+
+ ff->upload = hidpp_ff_upload_effect;
+ ff->erase = hidpp_ff_erase_effect;
+ ff->playback = hidpp_ff_playback;
+ ff->set_gain = hidpp_ff_set_gain;
+ ff->set_autocenter = hidpp_ff_set_autocenter;
+ ff->destroy = hidpp_ff_destroy;
+
+
+ /* reset all forces */
+ error = hidpp_send_fap_command_sync(hidpp, feature_index,
+ HIDPP_FF_RESET_ALL, NULL, 0, &response);
+
+ /* Read current Range */
+ error = hidpp_send_fap_command_sync(hidpp, feature_index,
+ HIDPP_FF_GET_APERTURE, NULL, 0, &response);
+ if (error)
+ hid_warn(hidpp->hid_dev, "Failed to read range from device.\n");
+ data->range = error ? 900 : get_unaligned_be16(&response.fap.params[0]);
+
+ /* Create sysfs interface */
+ error = device_create_file(&(hidpp->hid_dev->dev), &dev_attr_range);
+ if (error)
+ hid_warn(hidpp->hid_dev, "Unable to create sysfs interface for \"range\", errno %d\n", error);
+
+ /* Read the current gain values */
+ error = hidpp_send_fap_command_sync(hidpp, feature_index,
+ HIDPP_FF_GET_GLOBAL_GAINS, NULL, 0, &response);
+ if (error)
+ hid_warn(hidpp->hid_dev, "Failed to read gain values from device.\n");
+ data->gain = error ? 0xffff : get_unaligned_be16(&response.fap.params[0]);
+ /* ignore boost value at response.fap.params[2] */
+
+ /* init the hardware command queue */
+ data->wq = create_singlethread_workqueue("hidpp-ff-sendqueue");
+ atomic_set(&data->workqueue_size, 0);
+
+ return 0;
+}
+
+int hidpp_ff_deinit(struct hid_device *hid)
+{
+ struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+ struct input_dev *dev = hidinput->input;
+ struct hidpp_ff_private_data *data;
+
+ if (!dev) {
+ hid_err(hid, "Struct input_dev not found!\n");
+ return -EINVAL;
+ }
+
+ hid_info(hid, "Unloading HID++ force feedback.\n");
+ data = dev->ff->private;
+ if (!data) {
+ hid_err(hid, "Private data not found!\n");
+ return -EINVAL;
+ }
+
+ destroy_workqueue(data->wq);
+ device_remove_file(&hid->dev, &dev_attr_range);
+
+ return 0;
+}
diff --git a/drivers/hid/hid-logitech-hidpp-ff.h b/drivers/hid/hid-logitech-hidpp-ff.h
new file mode 100644
index 0000000..e153019
--- /dev/null
+++ b/drivers/hid/hid-logitech-hidpp-ff.h
@@ -0,0 +1,9 @@
+#ifndef __HID_LOGITECH_HIDPP_FF_H
+#define __HID_LOGITECH_HIDPP_FF_H
+
+#include "hid-logitech-hidpp-base.h"
+
+int hidpp_ff_init(struct hidpp_device *hidpp, u8 feature_index);
+int hidpp_ff_deinit(struct hid_device *hid);
+
+#endif
--
2.5.0

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