diff mbox series

[v3] HID: hid-google-stadiaff: add support for Stadia force feedback

Message ID 20230709214410.3676224-1-fabiobaltieri@chromium.org
State Superseded
Headers show
Series [v3] HID: hid-google-stadiaff: add support for Stadia force feedback | expand

Commit Message

Fabio Baltieri July 9, 2023, 9:44 p.m. UTC
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 <fabiobaltieri@chromium.org>
---

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

Comments

Rahul Rameshbabu July 14, 2023, 9:13 p.m. UTC | #1
On Sun, 09 Jul, 2023 21:44:10 +0000 Fabio Baltieri <fabiobaltieri@chromium.org> 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 <fabiobaltieri@chromium.org>
> ---
> +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
Fabio Baltieri July 16, 2023, 6:39 p.m. UTC | #2
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 <fabiobaltieri@chromium.org> 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 <fabiobaltieri@chromium.org>
> > ---
> > +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
Rahul Rameshbabu July 16, 2023, 6:47 p.m. UTC | #3
On Sun, 16 Jul, 2023 18:39:24 +0000 Fabio Baltieri <fabiobaltieri@chromium.org> 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 <fabiobaltieri@chromium.org> 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 <fabiobaltieri@chromium.org>
>> > ---
>> > +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
diff mbox series

Patch

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