On 4/20/24 5:34 AM, Max Maisel wrote:
> The Deck's controller features an accelerometer and gyroscope which
> send their measurement values by default in the main HID input report.
> Expose both sensors to userspace through a separate evdev node as it
> is done by the hid-nintendo and hid-playstation drivers.
>
> Signed-off-by: Max Maisel <mmm-1@xxxxxxxxxx>
> ---
>
> Changes in v2:
> * Increased gyroscope range to 32768.
> * Removed comment about factory calibration of sensor values.
> * Removed STEAM_QUIRK_DECK check in steam_raw_event function.
> * Silenced the IMU when gamepad mode is disabled.
> * Added improved fuzz values for the input device.
> The new values are based on the average deviation from the average
> sensor values at rest.
> * Rebased onto kernel v6.9-rc4.
> * Improved the test procedure below.
>
> Test procedure:
>
> This patch was tested on a Steam Deck running Arch Linux. With it,
> applications using latest SDL2/3 git libraries will pick up the sensors
> without hidraw access. This was tested against the antimicrox gamepad
> mapper.
>
> Measurement value scaling was tested by logging and comparing sensors
> values between the deck and a dualsense controller.
> For the accelerometer, both controllers were aligned to gravity on all axes
> and the reported values were compared.
> For the gyroscope, both controllers were placed on a makeshift
> rotational plate and the reported absolute angular velocity was compared.
> Furthermore, it was tested that the axes have the same orientation
> between the two controller types.
> Finally, it was tested that the full scale values for both sensor types
> can be reached by doing jerky movements with the deck.
> All observed values matched within a few percent error range.
>
> drivers/hid/hid-steam.c | 155 +++++++++++++++++++++++++++++++++++++---
> 1 file changed, 147 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/hid/hid-steam.c b/drivers/hid/hid-steam.c
> index b08a5ab58528..f166188c21ec 100644
> --- a/drivers/hid/hid-steam.c
> +++ b/drivers/hid/hid-steam.c
> @@ -66,6 +66,14 @@ static LIST_HEAD(steam_devices);
> #define STEAM_DECK_TRIGGER_RESOLUTION 5461
> /* Joystick runs are about 5 mm and 32768 units */
> #define STEAM_DECK_JOYSTICK_RESOLUTION 6553
> +/* Accelerometer has 16 bit resolution and a range of +/- 2g */
> +#define STEAM_DECK_ACCEL_RES_PER_G 16384
> +#define STEAM_DECK_ACCEL_RANGE 32768
> +#define STEAM_DECK_ACCEL_FUZZ 32
> +/* Gyroscope has 16 bit resolution and a range of +/- 2000 dps */
> +#define STEAM_DECK_GYRO_RES_PER_DPS 16
> +#define STEAM_DECK_GYRO_RANGE 32768
> +#define STEAM_DECK_GYRO_FUZZ 1
>
> #define STEAM_PAD_FUZZ 256
>
> @@ -288,6 +296,7 @@ struct steam_device {
> struct mutex report_mutex;
> unsigned long client_opened;
> struct input_dev __rcu *input;
> + struct input_dev __rcu *sensors;
> unsigned long quirks;
> struct work_struct work_connect;
> bool connected;
> @@ -302,6 +311,7 @@ struct steam_device {
> struct work_struct rumble_work;
> u16 rumble_left;
> u16 rumble_right;
> + unsigned int sensor_timestamp_us;
> };
>
> static int steam_recv_report(struct steam_device *steam,
> @@ -825,6 +835,74 @@ static int steam_input_register(struct steam_device *steam)
> return ret;
> }
>
> +static int steam_sensors_register(struct steam_device *steam)
> +{
> + struct hid_device *hdev = steam->hdev;
> + struct input_dev *sensors;
> + int ret;
> +
> + if (!(steam->quirks & STEAM_QUIRK_DECK))
> + return 0;
> +
> + rcu_read_lock();
> + sensors = rcu_dereference(steam->sensors);
> + rcu_read_unlock();
> + if (sensors) {
> + dbg_hid("%s: already connected\n", __func__);
> + return 0;
> + }
> +
> + sensors = input_allocate_device();
> + if (!sensors)
> + return -ENOMEM;
> +
> + input_set_drvdata(sensors, steam);
> + sensors->dev.parent = &hdev->dev;
> +
> + sensors->name = "Steam Deck Motion Sensors";
> + sensors->phys = hdev->phys;
> + sensors->uniq = steam->serial_no;
> + sensors->id.bustype = hdev->bus;
> + sensors->id.vendor = hdev->vendor;
> + sensors->id.product = hdev->product;
> + sensors->id.version = hdev->version;
> +
> + __set_bit(INPUT_PROP_ACCELEROMETER, sensors->propbit);
> + __set_bit(EV_MSC, sensors->evbit);
> + __set_bit(MSC_TIMESTAMP, sensors->mscbit);
> +
> + input_set_abs_params(sensors, ABS_X, -STEAM_DECK_ACCEL_RANGE,
> + STEAM_DECK_ACCEL_RANGE, STEAM_DECK_ACCEL_FUZZ, 0);
> + input_set_abs_params(sensors, ABS_Y, -STEAM_DECK_ACCEL_RANGE,
> + STEAM_DECK_ACCEL_RANGE, STEAM_DECK_ACCEL_FUZZ, 0);
> + input_set_abs_params(sensors, ABS_Z, -STEAM_DECK_ACCEL_RANGE,
> + STEAM_DECK_ACCEL_RANGE, STEAM_DECK_ACCEL_FUZZ, 0);
> + input_abs_set_res(sensors, ABS_X, STEAM_DECK_ACCEL_RES_PER_G);
> + input_abs_set_res(sensors, ABS_Y, STEAM_DECK_ACCEL_RES_PER_G);
> + input_abs_set_res(sensors, ABS_Z, STEAM_DECK_ACCEL_RES_PER_G);
> +
> + input_set_abs_params(sensors, ABS_RX, -STEAM_DECK_GYRO_RANGE,
> + STEAM_DECK_GYRO_RANGE, STEAM_DECK_GYRO_FUZZ, 0);
> + input_set_abs_params(sensors, ABS_RY, -STEAM_DECK_GYRO_RANGE,
> + STEAM_DECK_GYRO_RANGE, STEAM_DECK_GYRO_FUZZ, 0);
> + input_set_abs_params(sensors, ABS_RZ, -STEAM_DECK_GYRO_RANGE,
> + STEAM_DECK_GYRO_RANGE, STEAM_DECK_GYRO_FUZZ, 0);
> + input_abs_set_res(sensors, ABS_RX, STEAM_DECK_GYRO_RES_PER_DPS);
> + input_abs_set_res(sensors, ABS_RY, STEAM_DECK_GYRO_RES_PER_DPS);
> + input_abs_set_res(sensors, ABS_RZ, STEAM_DECK_GYRO_RES_PER_DPS);
> +
> + ret = input_register_device(sensors);
> + if (ret)
> + goto sensors_register_fail;
> +
> + rcu_assign_pointer(steam->sensors, sensors);
> + return 0;
> +
> +sensors_register_fail:
> + input_free_device(sensors);
> + return ret;
> +}
> +
> static void steam_input_unregister(struct steam_device *steam)
> {
> struct input_dev *input;
> @@ -838,6 +916,24 @@ static void steam_input_unregister(struct steam_device *steam)
> input_unregister_device(input);
> }
>
> +static void steam_sensors_unregister(struct steam_device *steam)
> +{
> + struct input_dev *sensors;
> +
> + if (!(steam->quirks & STEAM_QUIRK_DECK))
> + return;
> +
> + rcu_read_lock();
> + sensors = rcu_dereference(steam->sensors);
> + rcu_read_unlock();
> +
> + if (!sensors)
> + return;
> + RCU_INIT_POINTER(steam->sensors, NULL);
> + synchronize_rcu();
> + input_unregister_device(sensors);
> +}
> +
> static void steam_battery_unregister(struct steam_device *steam)
> {
> struct power_supply *battery;
> @@ -890,18 +986,28 @@ static int steam_register(struct steam_device *steam)
> spin_lock_irqsave(&steam->lock, flags);
> client_opened = steam->client_opened;
> spin_unlock_irqrestore(&steam->lock, flags);
> +
> if (!client_opened) {
> steam_set_lizard_mode(steam, lizard_mode);
> ret = steam_input_register(steam);
> - } else
> - ret = 0;
> + if (ret != 0)
> + goto steam_register_input_fail;
> + ret = steam_sensors_register(steam);
> + if (ret != 0)
> + goto steam_register_sensors_fail;
> + }
> + return 0;
>
> +steam_register_sensors_fail:
> + steam_input_unregister(steam);
> +steam_register_input_fail:
> return ret;
> }
>
> static void steam_unregister(struct steam_device *steam)
> {
> steam_battery_unregister(steam);
> + steam_sensors_unregister(steam);
> steam_input_unregister(steam);
> if (steam->serial_no[0]) {
> hid_info(steam->hdev, "Steam Controller '%s' disconnected",
> @@ -1010,6 +1116,7 @@ static int steam_client_ll_open(struct hid_device *hdev)
> steam->client_opened++;
> spin_unlock_irqrestore(&steam->lock, flags);
>
> + steam_sensors_unregister(steam);
> steam_input_unregister(steam);
>
> return 0;
> @@ -1030,6 +1137,7 @@ static void steam_client_ll_close(struct hid_device *hdev)
> if (connected) {
> steam_set_lizard_mode(steam, lizard_mode);
> steam_input_register(steam);
> + steam_sensors_register(steam);
> }
> }
>
> @@ -1121,6 +1229,7 @@ static int steam_probe(struct hid_device *hdev,
> INIT_DELAYED_WORK(&steam->mode_switch, steam_mode_switch_cb);
> INIT_LIST_HEAD(&steam->list);
> INIT_WORK(&steam->rumble_work, steam_haptic_rumble_cb);
> + steam->sensor_timestamp_us = 0;
>
> /*
> * With the real steam controller interface, do not connect hidraw.
> @@ -1380,12 +1489,12 @@ static void steam_do_input_event(struct steam_device *steam,
> * 18-19 | s16 | ABS_HAT0Y | left-pad Y value
> * 20-21 | s16 | ABS_HAT1X | right-pad X value
> * 22-23 | s16 | ABS_HAT1Y | right-pad Y value
> - * 24-25 | s16 | -- | accelerometer X value
> - * 26-27 | s16 | -- | accelerometer Y value
> - * 28-29 | s16 | -- | accelerometer Z value
> - * 30-31 | s16 | -- | gyro X value
> - * 32-33 | s16 | -- | gyro Y value
> - * 34-35 | s16 | -- | gyro Z value
> + * 24-25 | s16 | IMU ABS_X | accelerometer X value
> + * 26-27 | s16 | IMU ABS_Z | accelerometer Y value
> + * 28-29 | s16 | IMU ABS_Y | accelerometer Z value
> + * 30-31 | s16 | IMU ABS_RX | gyro X value
> + * 32-33 | s16 | IMU ABS_RZ | gyro Y value
> + * 34-35 | s16 | IMU ABS_RY | gyro Z value
> * 36-37 | s16 | -- | quaternion W value
> * 38-39 | s16 | -- | quaternion X value
> * 40-41 | s16 | -- | quaternion Y value
> @@ -1546,6 +1655,32 @@ static void steam_do_deck_input_event(struct steam_device *steam,
> input_sync(input);
> }
>
> +static void steam_do_deck_sensors_event(struct steam_device *steam,
> + struct input_dev *sensors, u8 *data)
> +{
> + /*
> + * The deck input report is received every 4 ms on average,
> + * with a jitter of +/- 4 ms even though the USB descriptor claims
> + * that it uses 1 kHz.
> + * Since the HID report does not include a sensor timestamp,
> + * use a fixed increment here.
> + */
> + steam->sensor_timestamp_us += 4000;
> +
> + if (!steam->gamepad_mode)
> + return;
> +
> + input_event(sensors, EV_MSC, MSC_TIMESTAMP, steam->sensor_timestamp_us);
> + input_report_abs(sensors, ABS_X, steam_le16(data + 24));
> + input_report_abs(sensors, ABS_Z, -steam_le16(data + 26));
> + input_report_abs(sensors, ABS_Y, steam_le16(data + 28));
> + input_report_abs(sensors, ABS_RX, steam_le16(data + 30));
> + input_report_abs(sensors, ABS_RZ, -steam_le16(data + 32));
> + input_report_abs(sensors, ABS_RY, steam_le16(data + 34));
> +
> + input_sync(sensors);
> +}
> +
> /*
> * The size for this message payload is 11.
> * The known values are:
> @@ -1583,6 +1718,7 @@ static int steam_raw_event(struct hid_device *hdev,
> {
> struct steam_device *steam = hid_get_drvdata(hdev);
> struct input_dev *input;
> + struct input_dev *sensors;
> struct power_supply *battery;
>
> if (!steam)
> @@ -1628,6 +1764,9 @@ static int steam_raw_event(struct hid_device *hdev,
> input = rcu_dereference(steam->input);
> if (likely(input))
> steam_do_deck_input_event(steam, input, data);
> + sensors = rcu_dereference(steam->sensors);
> + if (likely(sensors))
> + steam_do_deck_sensors_event(steam, sensors, data);
> rcu_read_unlock();
> break;
> case ID_CONTROLLER_WIRELESS:
>
> base-commit: 0bbac3facb5d6cc0171c45c9873a2dc96bea9680
Looks good.
Reviewed-by: Vicki Pfau <vi@xxxxxxxxxxx>
