Re: [RESEND PATCH 1/2] HID: Add driver for RC Simulator Controllers

Benjamin Tissoires
2022-08-23T12:41:30Z

Hi Marcus,

[and sorry for the delay in the review of your patches]

On Mon, Aug 22, 2022 at 8:04 AM Marcus Folkesson
<marcus.folkesson@gmail.com> wrote:
>
> Several RC Simulator Controllers are HID compliant with similar
> interface.
>
> Add support for these controllers:
> - Phoenix RC (HID variant)
> - Car VRC2.0
> - Real Flight G5/G6/G7
> - Aero Fly, FMS
> - OrangeRX FrSky
>
> Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
> ---
> Documentation/hid/index.rst | 1 +
> Documentation/hid/rcsim.rst | 142 ++++++++++++++++
> drivers/hid/Kconfig | 11 ++
> drivers/hid/Makefile | 1 +
> drivers/hid/hid-ids.h | 5 +
> drivers/hid/hid-rcsim.c | 315 ++++++++++++++++++++++++++++++++++++
> 6 files changed, 475 insertions(+)
> create mode 100644 Documentation/hid/rcsim.rst
> create mode 100644 drivers/hid/hid-rcsim.c
>
> diff --git a/Documentation/hid/index.rst b/Documentation/hid/index.rst
> index e50f513c579c..e5813d264f37 100644
> --- a/Documentation/hid/index.rst
> +++ b/Documentation/hid/index.rst
> @@ -17,3 +17,4 @@ Human Interface Devices (HID)
> hid-alps
> intel-ish-hid
> amd-sfh-hid
> + rcsim
> diff --git a/Documentation/hid/rcsim.rst b/Documentation/hid/rcsim.rst
> new file mode 100644
> index 000000000000..1a031f7189cb
> --- /dev/null
> +++ b/Documentation/hid/rcsim.rst
> @@ -0,0 +1,142 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +=================================
> +rcsim - RC Simulator Controllers
> +=================================
> +
> +:Author: Marcus Folkesson <marcus.folkesson@gmail.com>
> +
> +This driver let you use your own RC controller plugged
> +into your computer using an HID compatible USB dongle.
> +
> +There are several HID compatible USB dongles from different
> +vendors. The driver currently supports:
> +
> +- Phoenix RC (HID variant) (8ch)
> +- Car VRC2.0 (2ch)
> +- Real Flight G5/G6/G7 (6ch)
> +- Aero Fly, FMS (8ch)
> +- OrangeRX FrSky (6ch)
> +
> +Many RC controllers is able to configure which stick goes to which channel.
> +This is also configurable in most simulators, so a matching is not necessary.
> +
> +Supported dongles
> +==================
> +
> +PhoenixRC
> +----------
> +
> +The PhoenixRC has one HID compatible variant which is supported by this driver.
> +The controller has support for 8 analog channels.
> +
> +The driver is generating the following input event for on channels:
> +
> ++---------+----------------+
> +| Channel | Event |
> ++=========+================+
> +| 1 | ABS_Y |
> ++---------+----------------+
> +| 2 | ABS_X |
> ++---------+----------------+
> +| 3 | ABS_RY |
> ++---------+----------------+
> +| 4 | ABS_RX |
> ++---------+----------------+
> +| 5 | ABS_RUDDER |
> ++---------+----------------+
> +| 6 | ABS_THROTTLE |
> ++---------+----------------+
> +| 7 | ABS_Z |
> ++---------+----------------+
> +| 8 | ABS_RZ |
> ++---------+----------------+
> +
> +VRC2.0
> +----------
> +VRC2.0 is a controller for RC Cars.
> +The controller has support for 2 analog channels.
> +
> +The driver is generating the following input event for on channels:
> +
> ++---------+----------------+
> +| Channel | Event |
> ++=========+================+
> +| 1 | ABS_GAS |
> ++---------+----------------+
> +| 2 | ABS_WHEEL |
> ++---------+----------------+
> +
> +RealFlight
> +----------
> +
> +This driver supports Realflight G4-G7 and above
> +The controller has support for 4 analog channels and two buttons.
> +
> +The driver is generating the following input event for on channels:
> +
> ++---------+----------------+
> +| Channel | Event |
> ++=========+================+
> +| 1 | ABS_Y |
> ++---------+----------------+
> +| 2 | ABS_X |
> ++---------+----------------+
> +| 3 | ABS_RY |
> ++---------+----------------+
> +| 4 | ABS_RX |
> ++---------+----------------+
> +| 5 | BTN_A |
> ++---------+----------------+
> +| 6 | BTN_B |
> ++---------+----------------+
> +
> +XTR+G2+FMS Controllers
> +--------------------------------
> +
> +The controllers has support for 8 analog channels.
> +
> +The driver is generating the following input event for on channels:
> +
> ++---------+----------------+
> +| Channel | Event |
> ++=========+================+
> +| 1 | ABS_Y |
> ++---------+----------------+
> +| 2 | ABS_X |
> ++---------+----------------+
> +| 3 | ABS_RY |
> ++---------+----------------+
> +| 4 | ABS_RX |
> ++---------+----------------+
> +| 5 | ABS_RUDDER |
> ++---------+----------------+
> +| 6 | ABS_THROTTLE |
> ++---------+----------------+
> +| 7 | ABS_Z |
> ++---------+----------------+
> +| 8 | ABS_RZ |
> ++---------+----------------+
> +
> +OrangeRX
> +----------
> +
> +The controllers has support for 6 analog channels.
> +
> +The driver is generating the following input event for on channels:
> +
> ++---------+----------------+
> +| Channel | Event |
> ++=========+================+
> +| 1 | ABS_Y |
> ++---------+----------------+
> +| 2 | ABS_X |
> ++---------+----------------+
> +| 3 | ABS_RY |
> ++---------+----------------+
> +| 4 | ABS_RX |
> ++---------+----------------+
> +| 5 | ABS_RUDDER |
> ++---------+----------------+
> +| 6 | ABS_THROTTLE |
> ++---------+----------------+
> diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
> index 70da5931082f..d8313d36086c 100644
> --- a/drivers/hid/Kconfig
> +++ b/drivers/hid/Kconfig
> @@ -957,6 +957,17 @@ config HID_RAZER
> Support for Razer devices that are not fully compliant with the
> HID standard.
>
> +config HID_RCSIM
> + tristate "RC Simulator Controllers"
> + depends on HID
> + help
> + Support for several HID compatible RC Simulator Controllers including
> + - Phoenix RC
> + - Car VRC2.0
> + - Real Flight
> + - Aero Fly, FMS
> + - OrangeRX FrSky
> +
> config HID_PRIMAX
> tristate "Primax non-fully HID-compliant devices"
> depends on HID
> diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
> index cac2cbe26d11..85d50ab352ee 100644
> --- a/drivers/hid/Makefile
> +++ b/drivers/hid/Makefile
> @@ -102,6 +102,7 @@ obj-$(CONFIG_HID_PLANTRONICS) += hid-plantronics.o
> obj-$(CONFIG_HID_PLAYSTATION) += hid-playstation.o
> obj-$(CONFIG_HID_PRIMAX) += hid-primax.o
> obj-$(CONFIG_HID_RAZER) += hid-razer.o
> +obj-$(CONFIG_HID_RCSIM) += hid-rcsim.o

General rule of thumbs, we try to name the drivers after their
vendors, unless we know we have a generic driver.

Here, this driver seems to be really tied to a small set of devices,
and thus I don't think we can call it "generic".

> obj-$(CONFIG_HID_REDRAGON) += hid-redragon.o
> obj-$(CONFIG_HID_RETRODE) += hid-retrode.o
> obj-$(CONFIG_HID_ROCCAT) += hid-roccat.o hid-roccat-common.o \
> diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
> index d9eb676abe96..baf5f74d5bed 100644
> --- a/drivers/hid/hid-ids.h
> +++ b/drivers/hid/hid-ids.h
> @@ -1381,6 +1381,11 @@
>
> #define USB_VENDOR_ID_MULTIPLE_1781 0x1781
> #define USB_DEVICE_ID_RAPHNET_4NES4SNES_OLD 0x0a9d
> +#define USB_DEVICE_ID_PHOENIXRC 0x0898
> +#define USB_DEVICE_ID_REALFLIGHT 0x0e56
> +
> +#define USB_VENDOR_ID_DIPLING 0x0B9B
> +#define USB_DEVICE_ID_DIPLING_RCCONTROLLER 0x4012
>
> #define USB_VENDOR_ID_DRACAL_RAPHNET 0x289b
> #define USB_DEVICE_ID_RAPHNET_2NES2SNES 0x0002
> diff --git a/drivers/hid/hid-rcsim.c b/drivers/hid/hid-rcsim.c
> new file mode 100644
> index 000000000000..0f214cb5816a
> --- /dev/null
> +++ b/drivers/hid/hid-rcsim.c
> @@ -0,0 +1,315 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Driver for several HID compatible RC Simulator Controllers.
> + * Currently supported controllers are:
> + *
> + * - Phoenix RC (HID variant) (8ch)
> + * - Car VRC2.0 (2ch)
> + * - Real Flight G5/G6/G7 (6ch)
> + * - Aero Fly, FMS (8ch)
> + * - OrangeRX FrSky (6ch)
> + *
> + * Copyright (C) 2022 Marcus Folkesson <marcus.folkesson@gmail.com>
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/device.h>
> +#include <linux/input.h>
> +#include <linux/hid.h>
> +#include <linux/module.h>
> +#include <linux/usb.h>
> +
> +#include "hid-ids.h"
> +
> +/*
> + * Some of these VID/PID are probably "borrowed", so keep them locally and
> + * do not populate hid-ids.h with those.
> + */
> +
> +/* PHOENIXRC Controlloer (HID variant) */
> +#define PHOENIXRC_VID (USB_VENDOR_ID_MULTIPLE_1781)
> +#define PHOENIXRC_PID (USB_DEVICE_ID_PHOENIXRC)
> +#define PHOENIXRC_DSIZE (8)
> +
> +/* VRC2 Controlloer */
> +#define VRC2_VID (0x07c0)
> +#define VRC2_PID (0x1125)
> +#define VRC2_DSIZE (7)
> +
> +/* Realflight G4-&7 and Above Controller */
> +#define REALFLIGHT_VID (USB_VENDOR_ID_MULTIPLE_1781)
> +#define REALFLIGHT_PID (USB_DEVICE_ID_REALFLIGHT)
> +#define REALFLIGHT_DSIZE (8)
> +
> +#define REALFLIGHT_BTN_A BIT(0)
> +#define REALFLIGHT_BTN_B BIT(1)
> +
> +/* XTR+G2+FMS Controller */
> +#define XTRG2FMS_VID (USB_VENDOR_ID_DIPLING)
> +#define XTRG2FMS_PID (USB_DEVICE_ID_DIPLING_RCCONTROLLER)
> +#define XTRG2FMS_DSIZE (8)
> +
> +#define XTRG2FMS_X_HI GENMASK(3, 2)
> +#define XTRG2FMS_Y_HI GENMASK(1, 0)
> +#define XTRG2FMS_RX_HI GENMASK(7, 6)
> +#define XTRG2FMS_RY_HI GENMASK(5, 4)
> +#define XTRG2FMS_ALT1_HI GENMASK(3, 2)
> +#define XTRG2FMS_ALT2_HI GENMASK(1, 0)
> +
> +/* OrangeRX FrSky */
> +#define ORANGERX_VID (0x0451)
> +#define ORANGERX_PID (0x16a5)
> +#define ORANGERX_DSIZE (8)
> +
> +enum rcsim_controller {
> + PHOENIXRC,
> + VRC2,
> + REALFLIGHT,
> + XTRG2FMS,
> + ORANGERX
> +};
> +
> +struct rcsim_priv {
> + struct hid_device *hdev;
> + struct input_dev *input;
> + enum rcsim_controller controller;
> + u8 alt;
> +};
> +
> +static int rcsim_open(struct input_dev *dev)
> +{
> + struct rcsim_priv *priv = input_get_drvdata(dev);
> +
> + return hid_hw_open(priv->hdev);
> +}
> +
> +static void rcsim_close(struct input_dev *dev)
> +{
> + struct rcsim_priv *priv = input_get_drvdata(dev);
> +
> + hid_hw_close(priv->hdev);
> +}
> +
> +static int rcsim_setup_input(struct rcsim_priv *priv)
> +{
> + struct input_dev *input;
> +
> + input = devm_input_allocate_device(&priv->hdev->dev);
> + if (!input)
> + return -ENOMEM;
> +
> + input->id.bustype = priv->hdev->bus;
> + input->id.vendor = priv->hdev->vendor;
> + input->id.product = priv->hdev->product;
> + input->id.version = priv->hdev->bus;
> + input->phys = priv->hdev->phys;
> + input->uniq = priv->hdev->uniq;
> + input->open = rcsim_open;
> + input->close = rcsim_close;
> +
> + input_set_drvdata(input, priv);
> +
> + switch (priv->controller) {
> + case PHOENIXRC:
> + input_set_abs_params(input, ABS_X, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_Y, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_RX, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_RY, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_Z, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_RZ, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_RUDDER, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_THROTTLE, 0, 255, 0, 0);
> + input->name = "RC Simuator Controller PhoenixRC";
> + break;
> + case VRC2:
> + input_set_abs_params(input, ABS_GAS, 0, 2048, 0, 0);
> + input_set_abs_params(input, ABS_WHEEL, 0, 2048, 0, 0);
> + input->name = "RC Simuator Controller VRC2.0";
> + break;
> + case REALFLIGHT:
> + input_set_abs_params(input, ABS_X, 0, 1024, 0, 0);
> + input_set_abs_params(input, ABS_Y, 0, 1024, 0, 0);
> + input_set_abs_params(input, ABS_RX, 0, 1024, 0, 0);
> + input_set_abs_params(input, ABS_RY, 0, 1024, 0, 0);
> + input_set_capability(input, EV_KEY, BTN_A);
> + input_set_capability(input, EV_KEY, BTN_B);
> + input->name = "RC Simuator Controller Realflight";
> + break;
> + case XTRG2FMS:
> + input_set_abs_params(input, ABS_X, 0, 1024, 0, 0);
> + input_set_abs_params(input, ABS_Y, 0, 1024, 0, 0);
> + input_set_abs_params(input, ABS_RX, 0, 1024, 0, 0);
> + input_set_abs_params(input, ABS_RY, 0, 1024, 0, 0);
> + input_set_abs_params(input, ABS_Z, 0, 1024, 0, 0);
> + input_set_abs_params(input, ABS_RZ, 0, 1024, 0, 0);
> + input_set_abs_params(input, ABS_RUDDER, 0, 1024, 0, 0);
> + input_set_abs_params(input, ABS_THROTTLE, 0, 1024, 0, 0);
> + input->name = "RC Simuator Controller AeroFly, FMS";
> + priv->alt = 0;
> + break;
> + case ORANGERX:
> + input_set_abs_params(input, ABS_X, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_Y, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_RX, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_RY, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_RUDDER, 0, 255, 0, 0);
> + input_set_abs_params(input, ABS_THROTTLE, 0, 255, 0, 0);
> + input->name = "RC Simuator Controller OrangeRX FrSky";
> + break;
> + };
> +
> + priv->input = input;
> + return input_register_device(priv->input);
> +}

You are basically rewriting hid-input.c, which is suboptimal.

I guess the report descriptor provided by these devices are basically
useless, and so you have to parse the reports yourself in the
raw_event callback.

But instead of manually doing that, why not overwrite the report
descriptor (with .rdesc_fixup) and declare here all of the data that
needs to be exported. You could remove basically everything in this
driver by just providing a fixed report descriptor.

> +
> +static int rcsim_raw_event(struct hid_device *hdev,
> + struct hid_report *report,
> + u8 *raw_data, int size)
> +{
> + struct rcsim_priv *priv = hid_get_drvdata(hdev);
> + u16 value;
> +
> + switch (priv->controller) {
> + case PHOENIXRC:
> + if (size != PHOENIXRC_DSIZE)
> + break;
> +
> + /* X, RX, Y and RY, RUDDER and THROTTLE are sent every time */
> + input_report_abs(priv->input, ABS_X, raw_data[2]);
> + input_report_abs(priv->input, ABS_Y, raw_data[0]);
> + input_report_abs(priv->input, ABS_RX, raw_data[4]);
> + input_report_abs(priv->input, ABS_RY, raw_data[3]);
> + input_report_abs(priv->input, ABS_RUDDER, raw_data[5]);
> + input_report_abs(priv->input, ABS_THROTTLE, raw_data[6]);
> +
> + /* Z and RZ are sent every other time */
> + if (priv->alt)
> + input_report_abs(priv->input, ABS_Z, raw_data[7]);
> + else
> + input_report_abs(priv->input, ABS_RZ, raw_data[7]);
> +
> + priv->alt ^= 1;
> + break;
> + case VRC2:
> + if (size != VRC2_DSIZE)
> + break;
> + value = (raw_data[1] << 8 | raw_data[0]) & GENMASK(10, 0);
> + input_report_abs(priv->input, ABS_GAS, value);
> + value = (raw_data[3] << 8 | raw_data[2]) & GENMASK(10, 0);
> + input_report_abs(priv->input, ABS_WHEEL, value);
> + break;
> + case REALFLIGHT:
> + if (size != REALFLIGHT_DSIZE)
> + break;
> + input_report_abs(priv->input, ABS_X, raw_data[2]);
> + input_report_abs(priv->input, ABS_Y, raw_data[1]);
> + input_report_abs(priv->input, ABS_RX, raw_data[5]);
> + input_report_abs(priv->input, ABS_RY, raw_data[3]);
> + input_report_abs(priv->input, ABS_MISC, raw_data[4]);
> + input_report_key(priv->input, BTN_A,
> + raw_data[7] & REALFLIGHT_BTN_A);
> + input_report_key(priv->input, BTN_B,
> + raw_data[7] & REALFLIGHT_BTN_B);
> + break;
> + case XTRG2FMS:
> + if (size != XTRG2FMS_DSIZE)
> + break;
> +
> + /* X, RX, Y and RY are sent every time */
> + value = FIELD_GET(XTRG2FMS_X_HI, raw_data[3]);
> + value = (value << 8) | raw_data[1];
> + input_report_abs(priv->input, ABS_X, value);
> +
> + value = FIELD_GET(XTRG2FMS_Y_HI, raw_data[3]);
> + value = (value << 8) | raw_data[2];
> + input_report_abs(priv->input, ABS_Y, value);
> +
> + value = FIELD_GET(XTRG2FMS_RX_HI, raw_data[3]);
> + value = (value << 8) | raw_data[0];
> + input_report_abs(priv->input, ABS_RX, value);
> +
> + value = FIELD_GET(XTRG2FMS_RY_HI, raw_data[3]);
> + value = (value << 8) | raw_data[4];
> + input_report_abs(priv->input, ABS_RY, value);
> +
> + /* Z, RZ, RUDDER and THROTTLE are sent every other time */
> + value = FIELD_GET(XTRG2FMS_ALT1_HI, raw_data[7]);
> + value = (value << 8) | raw_data[6];
> + if (priv->alt)
> + input_report_abs(priv->input, ABS_Z, value);
> + else
> + input_report_abs(priv->input, ABS_RUDDER, value);
> +
> + value = FIELD_GET(XTRG2FMS_ALT2_HI, raw_data[7]);
> + value = (value << 8) | raw_data[5];
> + if (priv->alt)
> + input_report_abs(priv->input, ABS_RZ, value);
> + else
> + input_report_abs(priv->input, ABS_THROTTLE, value);
> +
> + priv->alt ^= 1;
> + break;
> + case ORANGERX:
> + if (size != ORANGERX_DSIZE)
> + break;
> + input_report_abs(priv->input, ABS_X, raw_data[0]);
> + input_report_abs(priv->input, ABS_Y, raw_data[2]);
> + input_report_abs(priv->input, ABS_RX, raw_data[3]);
> + input_report_abs(priv->input, ABS_RY, raw_data[1]);
> + input_report_abs(priv->input, ABS_RUDDER, raw_data[5]);
> + input_report_abs(priv->input, ABS_THROTTLE, raw_data[6]);
> + break;
> + };
> +
> + input_sync(priv->input);
> + return 0;
> +}
> +
> +static int rcsim_probe(struct hid_device *hdev, const struct hid_device_id *id)
> +{
> + struct device *dev = &hdev->dev;
> + struct rcsim_priv *priv;
> + int ret;
> +
> + if (!hid_is_using_ll_driver(hdev, &usb_hid_driver))
> + return -ENODEV;

You are not accessing anything in the USB stack, so there is no need
to prevent regression tests that could inject uhid devices to your
drivers.

Cheers,
Benjamin

> +
> + ret = hid_parse(hdev);
> + if (ret)
> + return ret;
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->hdev = hdev;
> + priv->controller = id->driver_data;
> + hid_set_drvdata(hdev, priv);
> +
> + ret = rcsim_setup_input(priv);
> + if (ret)
> + return ret;
> +
> + return hid_hw_start(hdev, HID_CONNECT_HIDRAW);
> +}
> +
> +static const struct hid_device_id rcsim_devices[] = {
> + { HID_USB_DEVICE(PHOENIXRC_VID, PHOENIXRC_PID), .driver_data = PHOENIXRC },
> + { HID_USB_DEVICE(VRC2_VID, VRC2_PID), .driver_data = VRC2 },
> + { HID_USB_DEVICE(REALFLIGHT_VID, REALFLIGHT_PID), .driver_data = REALFLIGHT },
> + { HID_USB_DEVICE(XTRG2FMS_VID, XTRG2FMS_PID), .driver_data = XTRG2FMS },
> + { HID_USB_DEVICE(ORANGERX_VID, ORANGERX_PID), .driver_data = ORANGERX },
> + { /* Sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(hid, rcsim_devices);
> +
> +static struct hid_driver rcsim_driver = {
> + .name = "rcsim",
> + .id_table = rcsim_devices,
> + .probe = rcsim_probe,
> + .raw_event = rcsim_raw_event,
> +};
> +module_hid_driver(rcsim_driver);
> +
> +MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
> +MODULE_LICENSE("GPL");
> --
> 2.37.1
>