On Tue, Aug 30, 2022 at 9:46 PM Marcus Folkesson
<marcus.folkesson@xxxxxxxxx> wrote:
>
> VRC-2 is 2-axis controller often used in car simulators.
>
> Signed-off-by: Marcus Folkesson <marcus.folkesson@xxxxxxxxx>
> ---
> MAINTAINERS | 6 +++
> drivers/hid/Kconfig | 9 ++++
> drivers/hid/Makefile | 1 +
> drivers/hid/hid-vrc2.c | 100 +++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 116 insertions(+)
> create mode 100644 drivers/hid/hid-vrc2.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 216b9f021f72..33010f93c993 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8919,6 +8919,12 @@ F: drivers/hid/hid-sensor-*
> F: drivers/iio/*/hid-*
> F: include/linux/hid-sensor-*
>
> +HID VRC-2 CAR CONTROLLER DRIVER
> +M: Marcus Folkesson <marcus.folkesson@xxxxxxxxx>
> +L: linux-input@xxxxxxxxxxxxxxx
> +S: Maintained
> +F: drivers/hid/hid-vrc2.c
> +
> HID WACOM DRIVER
> M: Ping Cheng <ping.cheng@xxxxxxxxx>
> M: Jason Gerecke <jason.gerecke@xxxxxxxxx>
> diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
> index d8313d36086c..518e0a5a7852 100644
> --- a/drivers/hid/Kconfig
> +++ b/drivers/hid/Kconfig
> @@ -481,6 +481,15 @@ config HID_VIEWSONIC
> help
> Support for ViewSonic/Signotec PD1011 signature pad.
>
> +config HID_VRC2
> + tristate "VRC-2 Car Controller"
> + depends on HID
> + help
> + Support for VRC-2 2-axis Car Controller
maybe "Support for VRC-2 which is a 2-axis controller often used in
car simulators." to be a little bit more explicit.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called hid-vrc2.
> +
> config HID_XIAOMI
> tristate "Xiaomi"
> depends on HID
> diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
> index 85d50ab352ee..32ab85b1a776 100644
> --- a/drivers/hid/Makefile
> +++ b/drivers/hid/Makefile
> @@ -137,6 +137,7 @@ obj-$(CONFIG_HID_XINMO) += hid-xinmo.o
> obj-$(CONFIG_HID_ZEROPLUS) += hid-zpff.o
> obj-$(CONFIG_HID_ZYDACRON) += hid-zydacron.o
> obj-$(CONFIG_HID_VIEWSONIC) += hid-viewsonic.o
> +obj-$(CONFIG_HID_VRC2) += hid-vrc2.o
>
> wacom-objs := wacom_wac.o wacom_sys.o
> obj-$(CONFIG_HID_WACOM) += wacom.o
> diff --git a/drivers/hid/hid-vrc2.c b/drivers/hid/hid-vrc2.c
> new file mode 100644
> index 000000000000..43c98607b837
> --- /dev/null
> +++ b/drivers/hid/hid-vrc2.c
> @@ -0,0 +1,100 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * HID driver for VRC-2 2-axis Car controller
> + *
> + * Copyright (C) 2022 Marcus Folkesson <marcus.folkesson@xxxxxxxxx>
> + */
> +
> +#include <linux/device.h>
> +#include <linux/hid.h>
> +#include <linux/module.h>
> +
> +/*
> + * VID/PID are probably "borrowed", so keep them locally and
> + * do not populate hid-ids.h with those.
> + */
> +#define USB_VENDOR_ID_VRC2 (0x07c0)
> +#define USB_DEVICE_ID_VRC2 (0x1125)
> +
> +static __u8 vrc2_rdesc_fixed[] = {
> + 0x05, 0x01, // Usage Page (Generic Desktop Ctrls)
> + 0x09, 0x04, // Usage (Joystick)
> + 0xA1, 0x01, // Collection (Application)
> + 0x09, 0x01, // Usage (Pointer)
> + 0xA1, 0x00, // Collection (Physical)
> + 0x09, 0x30, // Usage (X)
> + 0x09, 0x31, // Usage (Y)
> + 0x15, 0x00, // Logical Minimum (0)
> + 0x26, 0xFF, 0x07, // Logical Maximum (2047)
> + 0x35, 0x00, // Physical Minimum (0)
> + 0x46, 0xFF, 0x00, // Physical Maximum (255)
> + 0x75, 0x10, // Report Size (16)
> + 0x95, 0x02, // Report Count (2)
> + 0x81, 0x02, // Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
> + 0xC0, // End Collection
> + 0x75, 0x08, // Report Size (8)
> + 0x95, 0x03, // Report Count (3)
> + 0x81, 0x03, // Input (Cnst,Var,Abs)
> + 0xC0, // End Collection
> +};
> +
> +static __u8 *vrc2_report_fixup(struct hid_device *hdev, __u8 *rdesc,
> + unsigned int *rsize)
> +{
> + if (*rsize == 23)
> + return rdesc;
This test is not required. probe() returned -ENODEV for this
interface, so we are sure we have the correct one when we are there.
> +
> + hid_info(hdev, "fixing up VRC-2 report descriptor\n");
> + *rsize = sizeof(vrc2_rdesc_fixed);
> + return vrc2_rdesc_fixed;
> +}
> +
> +static int vrc2_probe(struct hid_device *hdev, const struct hid_device_id *id)
> +{
> + int ret;
> +
> + /*
> + * The device gives us 2 separate USB endpoints.
> + * One of those (the one with report descriptor size of 23) is just bogus so ignore it
> + */
> + if (hdev->dev_rsize == 23)
> + return -ENODEV;
> +
> + ret = hid_parse(hdev);
> + if (ret) {
> + hid_err(hdev, "parse failed\n");
> + return ret;
> + }
> +
> + ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
> + if (ret) {
> + hid_err(hdev, "hw start failed\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void vrc2_remove(struct hid_device *hdev)
> +{
> + hid_hw_stop(hdev);
> +}
I am pretty sure you can remove that vrc2_remove(), hid-core should be
able to call hid_hw_stop() for you.
> +
> +static const struct hid_device_id vrc2_devices[] = {
> + { HID_USB_DEVICE(USB_VENDOR_ID_VRC2, USB_DEVICE_ID_VRC2) },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(hid, vrc2_devices);
> +
> +static struct hid_driver vrc2_driver = {
> + .name = "vrc2",
> + .id_table = vrc2_devices,
> + .report_fixup = vrc2_report_fixup,
> + .probe = vrc2_probe,
> + .remove = vrc2_remove,
> +};
> +module_hid_driver(vrc2_driver);
> +
> +MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@xxxxxxxxx>");
> +MODULE_DESCRIPTION("HID driver for VRC-2 2-axis Car controller");
> +MODULE_LICENSE("GPL");
> --
> 2.37.1
>
Cheers,
Benjamin
