2023-07-09 23:00:27

by Fabio Baltieri

[permalink] [raw]
Subject: [PATCH v3] HID: hid-google-stadiaff: add support for Stadia force feedback

Add a hid-stadiaff module to support rumble based force feedback on the
Google Stadia controller. This works using the HID output endpoint
exposed on both the USB and BLE interface.

Signed-off-by: Fabio Baltieri <[email protected]>
---

Hi, this adds rumble support to the stadia controller using the input
interface. Up to now this has only been implemented at application level
using hidraw:

https://source.chromium.org/chromium/chromium/src/+/main:device/gamepad/hid_haptic_gamepad.cc

Tested with fftest, works both over USB and BLE.

Changes from v2:
- check stadiaff_init value at probe time and fail the probe if init
fails

Changes from v1:
- renamed the module to hid-google-stadiaff.c
- added locking for passing the state to the worker code
- added a module removed check to prevent the work from rescheduling

drivers/hid/Kconfig | 7 ++
drivers/hid/Makefile | 1 +
drivers/hid/hid-google-stadiaff.c | 158 ++++++++++++++++++++++++++++++
drivers/hid/hid-ids.h | 1 +
4 files changed, 167 insertions(+)
create mode 100644 drivers/hid/hid-google-stadiaff.c

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 4ce012f83253..ea1646384b20 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -412,6 +412,13 @@ config HID_GOOGLE_HAMMER
help
Say Y here if you have a Google Hammer device.

+config HID_GOOGLE_STADIA_FF
+ tristate "Google Stadia force feedback"
+ select INPUT_FF_MEMLESS
+ help
+ Say Y here if you want to enable force feedback support for the Google
+ Stadia controller.
+
config HID_VIVALDI
tristate "Vivaldi Keyboard"
select HID_VIVALDI_COMMON
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 5d37cacbde33..18e9a3afecab 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -55,6 +55,7 @@ obj-$(CONFIG_HID_GFRM) += hid-gfrm.o
obj-$(CONFIG_HID_GLORIOUS) += hid-glorious.o
obj-$(CONFIG_HID_VIVALDI_COMMON) += hid-vivaldi-common.o
obj-$(CONFIG_HID_GOOGLE_HAMMER) += hid-google-hammer.o
+obj-$(CONFIG_HID_GOOGLE_STADIA_FF) += hid-google-stadiaff.o
obj-$(CONFIG_HID_VIVALDI) += hid-vivaldi.o
obj-$(CONFIG_HID_GT683R) += hid-gt683r.o
obj-$(CONFIG_HID_GYRATION) += hid-gyration.o
diff --git a/drivers/hid/hid-google-stadiaff.c b/drivers/hid/hid-google-stadiaff.c
new file mode 100644
index 000000000000..f8ca7209917d
--- /dev/null
+++ b/drivers/hid/hid-google-stadiaff.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Stadia controller rumble support.
+ *
+ * Copyright 2023 Google LLC
+ */
+
+#include <linux/hid.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define STADIA_FF_REPORT_ID 5
+
+struct stadiaff_device {
+ struct hid_device *hid;
+ struct hid_report *report;
+ spinlock_t lock;
+ bool removed;
+ uint16_t strong_magnitude;
+ uint16_t weak_magnitude;
+ struct work_struct work;
+};
+
+static void stadiaff_work(struct work_struct *work)
+{
+ struct stadiaff_device *stadiaff =
+ container_of(work, struct stadiaff_device, work);
+ struct hid_field *rumble_field = stadiaff->report->field[0];
+ unsigned long flags;
+
+ spin_lock_irqsave(&stadiaff->lock, flags);
+ rumble_field->value[0] = stadiaff->strong_magnitude;
+ rumble_field->value[1] = stadiaff->weak_magnitude;
+ spin_unlock_irqrestore(&stadiaff->lock, flags);
+
+ hid_hw_request(stadiaff->hid, stadiaff->report, HID_REQ_SET_REPORT);
+}
+
+static int stadiaff_play(struct input_dev *dev, void *data,
+ struct ff_effect *effect)
+{
+ struct hid_device *hid = input_get_drvdata(dev);
+ struct stadiaff_device *stadiaff = hid_get_drvdata(hid);
+ unsigned long flags;
+
+ spin_lock_irqsave(&stadiaff->lock, flags);
+ if (!stadiaff->removed) {
+ stadiaff->strong_magnitude = effect->u.rumble.strong_magnitude;
+ stadiaff->weak_magnitude = effect->u.rumble.weak_magnitude;
+ schedule_work(&stadiaff->work);
+ }
+ spin_unlock_irqrestore(&stadiaff->lock, flags);
+
+ return 0;
+}
+
+static int stadiaff_init(struct hid_device *hid)
+{
+ struct stadiaff_device *stadiaff;
+ struct hid_report *report;
+ struct hid_input *hidinput;
+ struct input_dev *dev;
+ int error;
+
+ if (list_empty(&hid->inputs)) {
+ hid_err(hid, "no inputs found\n");
+ return -ENODEV;
+ }
+ hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+ dev = hidinput->input;
+
+ report = hid_validate_values(hid, HID_OUTPUT_REPORT,
+ STADIA_FF_REPORT_ID, 0, 2);
+ if (!report)
+ return -ENODEV;
+
+ stadiaff = devm_kzalloc(&hid->dev, sizeof(struct stadiaff_device),
+ GFP_KERNEL);
+ if (!stadiaff)
+ return -ENOMEM;
+
+ hid_set_drvdata(hid, stadiaff);
+
+ input_set_capability(dev, EV_FF, FF_RUMBLE);
+
+ error = input_ff_create_memless(dev, NULL, stadiaff_play);
+ if (error)
+ return error;
+
+ stadiaff->removed = false;
+ stadiaff->hid = hid;
+ stadiaff->report = report;
+ INIT_WORK(&stadiaff->work, stadiaff_work);
+ spin_lock_init(&stadiaff->lock);
+
+ hid_info(hid, "Force Feedback for Google Stadia controller\n");
+
+ return 0;
+}
+
+static int stadia_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+ int ret;
+
+ ret = hid_parse(hdev);
+ if (ret) {
+ hid_err(hdev, "parse failed\n");
+ return ret;
+ }
+
+ ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
+ if (ret) {
+ hid_err(hdev, "hw start failed\n");
+ return ret;
+ }
+
+ ret = stadiaff_init(hdev);
+ if (ret) {
+ dev_err(&hdev->dev, "force feedback init failed\n");
+ hid_hw_stop(hdev);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void stadia_remove(struct hid_device *hid)
+{
+ struct stadiaff_device *stadiaff = hid_get_drvdata(hid);
+ unsigned long flags;
+
+ spin_lock_irqsave(&stadiaff->lock, flags);
+ stadiaff->removed = true;
+ spin_unlock_irqrestore(&stadiaff->lock, flags);
+
+ cancel_work_sync(&stadiaff->work);
+ hid_hw_stop(hid);
+}
+
+static const struct hid_device_id stadia_devices[] = {
+ { HID_USB_DEVICE(USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STADIA) },
+ { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STADIA) },
+ { }
+};
+MODULE_DEVICE_TABLE(hid, stadia_devices);
+
+static struct hid_driver stadia_driver = {
+ .name = "stadia",
+ .id_table = stadia_devices,
+ .probe = stadia_probe,
+ .remove = stadia_remove,
+};
+module_hid_driver(stadia_driver);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index d79e946acdcb..366c95904e4f 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -529,6 +529,7 @@
#define USB_DEVICE_ID_GOOGLE_MOONBALL 0x5044
#define USB_DEVICE_ID_GOOGLE_DON 0x5050
#define USB_DEVICE_ID_GOOGLE_EEL 0x5057
+#define USB_DEVICE_ID_GOOGLE_STADIA 0x9400

#define USB_VENDOR_ID_GOTOP 0x08f2
#define USB_DEVICE_ID_SUPER_Q2 0x007f
--
2.41.0.255.g8b1d071c50-goog



2023-07-14 22:04:08

by Rahul Rameshbabu

[permalink] [raw]
Subject: Re: [PATCH v3] HID: hid-google-stadiaff: add support for Stadia force feedback

On Sun, 09 Jul, 2023 21:44:10 +0000 Fabio Baltieri <[email protected]> wrote:
> Add a hid-stadiaff module to support rumble based force feedback on the
> Google Stadia controller. This works using the HID output endpoint
> exposed on both the USB and BLE interface.
>
> Signed-off-by: Fabio Baltieri <[email protected]>
> ---
> +static int stadia_probe(struct hid_device *hdev, const struct hid_device_id *id)
> +{
> + int ret;
> +
> + ret = hid_parse(hdev);
> + if (ret) {
> + hid_err(hdev, "parse failed\n");
> + return ret;
> + }
> +
> + ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
> + if (ret) {
> + hid_err(hdev, "hw start failed\n");
> + return ret;
> + }
> +
> + ret = stadiaff_init(hdev);
> + if (ret) {
> + dev_err(&hdev->dev, "force feedback init failed\n");

Error handling looks good to me now. Is there any particular reason you
use dev_err here instead of hid_err here?

-- Rahul Rameshbabu

2023-07-16 18:50:25

by Fabio Baltieri

[permalink] [raw]
Subject: Re: [PATCH v3] HID: hid-google-stadiaff: add support for Stadia force feedback

Hi Rahul,

On Fri, Jul 14, 2023 at 02:13:34PM -0700, Rahul Rameshbabu wrote:
> On Sun, 09 Jul, 2023 21:44:10 +0000 Fabio Baltieri <[email protected]> wrote:
> > Add a hid-stadiaff module to support rumble based force feedback on the
> > Google Stadia controller. This works using the HID output endpoint
> > exposed on both the USB and BLE interface.
> >
> > Signed-off-by: Fabio Baltieri <[email protected]>
> > ---
> > +static int stadia_probe(struct hid_device *hdev, const struct hid_device_id *id)
> > +{
> > + int ret;
> > +
> > + ret = hid_parse(hdev);
> > + if (ret) {
> > + hid_err(hdev, "parse failed\n");
> > + return ret;
> > + }
> > +
> > + ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
> > + if (ret) {
> > + hid_err(hdev, "hw start failed\n");
> > + return ret;
> > + }
> > +
> > + ret = stadiaff_init(hdev);
> > + if (ret) {
> > + dev_err(&hdev->dev, "force feedback init failed\n");
>
> Error handling looks good to me now. Is there any particular reason you
> use dev_err here instead of hid_err here?

Not really, copied from another hid driver and did not realize the
inconsistency. I'll fix that up and send a v4.

Thanks again for spotting this!

Fabio

2023-07-16 19:12:54

by Rahul Rameshbabu

[permalink] [raw]
Subject: Re: [PATCH v3] HID: hid-google-stadiaff: add support for Stadia force feedback

On Sun, 16 Jul, 2023 18:39:24 +0000 Fabio Baltieri <[email protected]> wrote:
> Hi Rahul,
>
> On Fri, Jul 14, 2023 at 02:13:34PM -0700, Rahul Rameshbabu wrote:
>> On Sun, 09 Jul, 2023 21:44:10 +0000 Fabio Baltieri <[email protected]> wrote:
>> > Add a hid-stadiaff module to support rumble based force feedback on the
>> > Google Stadia controller. This works using the HID output endpoint
>> > exposed on both the USB and BLE interface.
>> >
>> > Signed-off-by: Fabio Baltieri <[email protected]>
>> > ---
>> > +static int stadia_probe(struct hid_device *hdev, const struct hid_device_id *id)
>> > +{
>> > + int ret;
>> > +
>> > + ret = hid_parse(hdev);
>> > + if (ret) {
>> > + hid_err(hdev, "parse failed\n");
>> > + return ret;
>> > + }
>> > +
>> > + ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
>> > + if (ret) {
>> > + hid_err(hdev, "hw start failed\n");
>> > + return ret;
>> > + }
>> > +
>> > + ret = stadiaff_init(hdev);
>> > + if (ret) {
>> > + dev_err(&hdev->dev, "force feedback init failed\n");
>>
>> Error handling looks good to me now. Is there any particular reason you
>> use dev_err here instead of hid_err here?
>
> Not really, copied from another hid driver and did not realize the
> inconsistency. I'll fix that up and send a v4.
>
> Thanks again for spotting this!

No worries. Btw, in your commit message body, you might want to change
hid-stadiaff to hid-google-stadiaff as well for your v4 submission.

Thanks,

-- Rahul Rameshbabu