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Message-ID: <CAHp75VfPK=yAx9TLEX-W0SrK8xXQzrP4wAuFWS3zEjHGoPJRsw@mail.gmail.com>
Date: Wed, 28 Feb 2018 21:21:15 +0200
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Rodrigo Rivas Costa <rodrigorivascosta@...il.com>
Cc: Jiri Kosina <jikos@...nel.org>,
Benjamin Tissoires <benjamin.tissoires@...hat.com>,
"Pierre-Loup A. Griffais" <pgriffais@...vesoftware.com>,
Cameron Gutman <aicommander@...il.com>,
Clément VUCHENER <clement.vuchener@...il.com>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
linux-input <linux-input@...r.kernel.org>
Subject: Re: [PATCH v4 1/4] HID: add driver for Valve Steam Controller
On Wed, Feb 28, 2018 at 8:43 PM, Rodrigo Rivas Costa
<rodrigorivascosta@...il.com> wrote:
> There are two ways to connect the Steam Controller: directly to the USB
> or with the USB wireless adapter. Both methods are similar, but the
> wireless adapter can connect up to 4 devices at the same time.
>
> The wired device will appear as 3 interfaces: a virtual mouse, a virtual
> keyboard and a custom HID device.
>
> The wireless device will appear as 5 interfaces: a virtual keyboard and
> 4 custom HID devices, that will remain silent until a device is actually
> connected.
>
> The custom HID device has a report descriptor with all vendor specific
> usages, so the hid-generic is not very useful. In a PC/SteamBox Valve
> Steam Client provices a software translation by using direct USB access
> and a creates a uinput virtual gamepad.
>
> This driver was reverse engineered to provide direct kernel support in
> case you cannot, or do not want to, use Valve Steam Client. It disables
> the virtual keyboard and mouse, as they are not so useful when you have
> a working gamepad.
> +// SPDX-License-Identifier: GPL-2.0
> +MODULE_LICENSE("GPL");
Not the same.
> +static void steam_unregister(struct steam_device *steam)
> +{
> + struct input_dev *input;
> +
> + rcu_read_lock();
> + input = rcu_dereference(steam->input);
> + rcu_read_unlock();
> +
> + if (input) {
if (!input)
return;
?
> + RCU_INIT_POINTER(steam->input, NULL);
> + synchronize_rcu();
> + hid_info(steam->hdev, "Steam Controller disconnected");
> + input_unregister_device(input);
> + }
> +}
> +static bool steam_is_valve_interface(struct hid_device *hdev)
> +{
> + struct hid_report_enum *rep_enum;
> + struct hid_report *hreport;
> +
> + /*
> + * The wired device creates 3 interfaces:
> + * 0: emulated mouse.
> + * 1: emulated keyboard.
> + * 2: the real game pad.
> + * The wireless device creates 5 interfaces:
> + * 0: emulated keyboard.
> + * 1-4: slots where up to 4 real game pads will be connected to.
> + * We know which one is the real gamepad interface because they are the
> + * only ones with a feature report.
> + */
> + rep_enum = &hdev->report_enum[HID_FEATURE_REPORT];
> + list_for_each_entry(hreport, &rep_enum->report_list, list) {
> + /* should we check hreport->id == 0? */
> + return true;
> + }
> + return false;
So, for now it's just an equivalent of
return !list_empty();
?
> +}
> + /*
> + * From this point on, if anything fails return 0 and ignores
> + * the error, so that the default HID devices are still bound.
> + */
> + steam = devm_kzalloc(&hdev->dev,
> + sizeof(struct steam_device), GFP_KERNEL);
sizeof(*steam) saves a line.
> + if (!steam) {
> + ret = -ENOMEM;
> + goto mem_fail;
> + }
> +static void steam_remove(struct hid_device *hdev)
> +{
> + struct steam_device *steam = hid_get_drvdata(hdev);
> +
> + if (steam && (steam->quirks & STEAM_QUIRK_WIRELESS)) {
> + hid_info(hdev, "Steam wireless receiver disconnected");
> + hid_hw_close(hdev);
> + }
> +
> + hid_hw_stop(hdev);
> +
> + if (steam) {
> + cancel_work_sync(&steam->work_connect);
> + steam_unregister(steam);
> + hid_set_drvdata(hdev, NULL);
Hmm.. Doesn't HID do this?
> + }
if (steam) {
...
hid_hw_stop(hdev);
...
} else {
hid_hw_stop(hdev);
}
?
> +}
> +static void steam_do_input_event(struct steam_device *steam,
> + struct input_dev *input, u8 *data)
> +{
> + /* 24 bits of buttons */
> + u8 b8, b9, b10;
> + bool lpad_touched, lpad_and_joy;
> +
> + b8 = data[8];
> + b9 = data[9];
> + b10 = data[10];
> +
> + input_report_abs(input, ABS_Z, data[11]);
> + input_report_abs(input, ABS_RZ, data[12]);
> +
> + /*
> + * These two bits tells how to interpret the values X and Y.
> + * lpad_and_joy tells that the joystick and the lpad are used at the
> + * same time.
> + * lpad_touched tells whether X/Y are to be read as lpad coord or
> + * joystick values.
> + * (lpad_touched || lpad_and_joy) tells if the lpad is really touched.
> + */
> + lpad_touched = b10 & 0x08;
BIT(3) ?
> + lpad_and_joy = b10 & 0x80;
BIT(7) ?
> + input_event(input, EV_KEY, BTN_TR2, !!(b8 & 0x01));
> + input_event(input, EV_KEY, BTN_TL2, !!(b8 & 0x02));
> + input_event(input, EV_KEY, BTN_TR, !!(b8 & 0x04));
> + input_event(input, EV_KEY, BTN_TL, !!(b8 & 0x08));
> + input_event(input, EV_KEY, BTN_Y, !!(b8 & 0x10));
> + input_event(input, EV_KEY, BTN_B, !!(b8 & 0x20));
> + input_event(input, EV_KEY, BTN_X, !!(b8 & 0x40));
> + input_event(input, EV_KEY, BTN_A, !!(b8 & 0x80));
> + input_event(input, EV_KEY, BTN_SELECT, !!(b9 & 0x10));
> + input_event(input, EV_KEY, BTN_MODE, !!(b9 & 0x20));
> + input_event(input, EV_KEY, BTN_START, !!(b9 & 0x40));
> + input_event(input, EV_KEY, BTN_GEAR_DOWN, !!(b9 & 0x80));
> + input_event(input, EV_KEY, BTN_GEAR_UP, !!(b10 & 0x01));
> + input_event(input, EV_KEY, BTN_THUMBR, !!(b10 & 0x04));
> + input_event(input, EV_KEY, BTN_THUMBL, !!(b10 & 0x40));
> + input_event(input, EV_KEY, BTN_THUMB, lpad_touched || lpad_and_joy);
> + input_event(input, EV_KEY, BTN_THUMB2, !!(b10 & 0x10));
BIT(x) ?
> +
> + input_report_abs(input, ABS_HAT0X,
> + !!(b9 & 0x02) - !!(b9 & 0x04));
> + input_report_abs(input, ABS_HAT0Y,
> + !!(b9 & 0x08) - !!(b9 & 0x01));
BIT(x) ?
> +}
> +static int steam_raw_event(struct hid_device *hdev,
> + struct hid_report *report, u8 *data,
> + int size)
> +{
> + struct steam_device *steam = hid_get_drvdata(hdev);
> + struct input_dev *input;
> +
> + if (!steam)
> + return 0;
When it's possible?
> + return 0;
> +}
--
With Best Regards,
Andy Shevchenko
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