Hi


2020. december 19., szombat 7:23 keltezéssel, Roderick Colenbrander írta:

I believe it would be preferable to keep the list of includes lexicographically
sorted.

+#include "hid-ids.h"
+
+/* Base class for playstation devices. */
+struct ps_device {
+	struct hid_device *hdev;
+
+	int (*parse_report)(struct ps_device *dev, struct hid_report *report, u8 *data, int size);
+};
+
+#define DS_INPUT_REPORT_USB			0x01
+
+/* Button masks for DualSense input report. */
+#define DS_BUTTONS0_HAT_SWITCH	GENMASK(3, 0)
+#define DS_BUTTONS0_SQUARE	BIT(4)
+#define DS_BUTTONS0_CROSS	BIT(5)
+#define DS_BUTTONS0_CIRCLE	BIT(6)
+#define DS_BUTTONS0_TRIANGLE	BIT(7)
+#define DS_BUTTONS1_L1		BIT(0)
+#define DS_BUTTONS1_R1		BIT(1)
+#define DS_BUTTONS1_L2		BIT(2)
+#define DS_BUTTONS1_R2		BIT(3)
+#define DS_BUTTONS1_CREATE	BIT(4)
+#define DS_BUTTONS1_OPTIONS	BIT(5)
+#define DS_BUTTONS1_L3		BIT(6)
+#define DS_BUTTONS1_R3		BIT(7)
+#define DS_BUTTONS2_PS_HOME	BIT(0)
+#define DS_BUTTONS2_TOUCHPAD	BIT(1)

I believe it would be preferable to explicitly include everything you need
and not to count on other headers indirectly including it for you. In this
case `linux/bits.h` is not included.

[...]
+/* Common gamepad buttons across DualShock 3 / 4 and DualSense.
+ * Note: for device with a touchpad, touchpad button is not included
+ *        as it will be part of the touchpad device.
+ */
+static int ps_gamepad_buttons[] = {

Any reason why it's not `const`?

+	BTN_WEST, /* Square */
+	BTN_NORTH, /* Triangle */
+	BTN_EAST, /* Circle */
+	BTN_SOUTH, /* Cross */
+	BTN_TL, /* L1 */
+	BTN_TR, /* R1 */
+	BTN_TL2, /* L2 */
+	BTN_TR2, /* R2 */
+	BTN_SELECT, /* Create (PS5) / Share (PS4) */
+	BTN_START, /* Option */
+	BTN_THUMBL, /* L3 */
+	BTN_THUMBR, /* R3 */
+	BTN_MODE, /* PS Home */
+};
[...]
+static struct input_dev *ps_allocate_input_dev(struct hid_device *hdev, const char *name_suffix)
+{
+	struct input_dev *input_dev;
+
+	input_dev = devm_input_allocate_device(&hdev->dev);
+	if (!input_dev)
+		return ERR_PTR(-ENOMEM);
+
+	input_dev->id.bustype = hdev->bus;
+	input_dev->id.vendor = hdev->vendor;
+	input_dev->id.product = hdev->product;
+	input_dev->id.version = hdev->version;
+	input_dev->uniq = hdev->uniq;
+
+	if (name_suffix) {
+		input_dev->name = devm_kasprintf(&hdev->dev, GFP_KERNEL, "%s %s", hdev->name,
+				name_suffix);
+		if (!input_dev->name)
+			return ERR_PTR(-ENOMEM);
+	} else
+		input_dev->name = hdev->name;
+

As per [1], please use braces around the body of the `else`.

+	input_set_drvdata(input_dev, hdev);
+
+	return input_dev;
+}
[...]
+static int dualsense_parse_report(struct ps_device *ps_dev, struct hid_report *report,
+		u8 *data, int size)
+{
+	struct hid_device *hdev = ps_dev->hdev;
+	struct dualsense *ds = (struct dualsense *)ps_dev;

I believe `container_of(ps_dev, struct dualsense, base)` would be preferable here
(and everywhere this pattern emerges).

+	struct dualsense_input_report *ds_report;
+	uint8_t value;
+
+	/* DualSense in USB uses the full HID report for reportID 1, but
+	 * Bluetooth uses a minimal HID report for reportID 1 and reports
+	 * the full report using reportID 49.
+	 */
+	if (report->id == DS_INPUT_REPORT_USB && hdev->bus == BUS_USB) {
+		ds_report = (struct dualsense_input_report *)&data[1];
+	} else {
+		hid_err(hdev, "Unhandled reportID=%d\n", report->id);
+		return -1;
+	}
+
+	input_report_abs(ds->gamepad, ABS_X, ds_report->x);
+	input_report_abs(ds->gamepad, ABS_Y, ds_report->y);
+	input_report_abs(ds->gamepad, ABS_RX, ds_report->rx);
+	input_report_abs(ds->gamepad, ABS_RY, ds_report->ry);
+	input_report_abs(ds->gamepad, ABS_Z, ds_report->z);
+	input_report_abs(ds->gamepad, ABS_RZ, ds_report->rz);
+
+	value = ds_report->buttons[0] & DS_BUTTONS0_HAT_SWITCH;
+	if (value > 7)
+		value = 8; /* center */
+	input_report_abs(ds->gamepad, ABS_HAT0X, ps_gamepad_hat_mapping[value].x);
+	input_report_abs(ds->gamepad, ABS_HAT0Y, ps_gamepad_hat_mapping[value].y);
+
+	input_report_key(ds->gamepad, BTN_WEST, ds_report->buttons[0] & DS_BUTTONS0_SQUARE);
+	input_report_key(ds->gamepad, BTN_SOUTH, ds_report->buttons[0] & DS_BUTTONS0_CROSS);
+	input_report_key(ds->gamepad, BTN_EAST, ds_report->buttons[0] & DS_BUTTONS0_CIRCLE);
+	input_report_key(ds->gamepad, BTN_NORTH, ds_report->buttons[0] & DS_BUTTONS0_TRIANGLE);
+	input_report_key(ds->gamepad, BTN_TL, ds_report->buttons[1] & DS_BUTTONS1_L1);
+	input_report_key(ds->gamepad, BTN_TR, ds_report->buttons[1] & DS_BUTTONS1_R1);
+	input_report_key(ds->gamepad, BTN_TL2, ds_report->buttons[1] & DS_BUTTONS1_L2);
+	input_report_key(ds->gamepad, BTN_TR2, ds_report->buttons[1] & DS_BUTTONS1_R2);
+	input_report_key(ds->gamepad, BTN_SELECT, ds_report->buttons[1] & DS_BUTTONS1_CREATE);
+	input_report_key(ds->gamepad, BTN_START, ds_report->buttons[1] & DS_BUTTONS1_OPTIONS);
+	input_report_key(ds->gamepad, BTN_THUMBL, ds_report->buttons[1] & DS_BUTTONS1_L3);
+	input_report_key(ds->gamepad, BTN_THUMBR, ds_report->buttons[1] & DS_BUTTONS1_R3);
+	input_report_key(ds->gamepad, BTN_MODE, ds_report->buttons[2] & DS_BUTTONS2_PS_HOME);

Possibly this could be replaced with a loop? I have something like this in mind:

struct ps_gamepad_button {
  unsigned int code;
  uint8_t button_idx;
  uint8_t mask;
} ps_gamepad_buttons[] = {...};

for (...) {
  struct ps_gamepad_button *b = ...;
  input_report_key(...);
}

Or is there any reason why the unrolled version is preffered that I'm missing?

+	input_sync(ds->gamepad);
+
+	return 0;
+}
+
+static struct ps_device *dualsense_create(struct hid_device *hdev)
+{
+	struct dualsense *ds;
+	int ret;
+
+	ds = devm_kzalloc(&hdev->dev, sizeof(*ds), GFP_KERNEL);
+	if (!ds)
+		return ERR_PTR(-ENOMEM);
+
+	/* Patch version to allow userspace to distinguish between
+	 * hid-generic vs hid-playstation axis and button mapping.
+	 */
+	hdev->version |= 0x8000;

Maybe that '0x8000' could be given a name?

+
+	ds->base.hdev = hdev;
+	ds->base.parse_report = dualsense_parse_report;
+	hid_set_drvdata(hdev, ds);
+
+	ds->gamepad = ps_gamepad_create(hdev);
+	if (IS_ERR(ds->gamepad)) {
+		ret = PTR_ERR(ds->gamepad);
+		goto err;
+	}
+
+	return (struct ps_device *)ds;

I believe using `&ds->base` instead of `(struct ps_device *)ds` would be somewhat
better as it does not subvert the type system as much.

+
+err:
+	return ERR_PTR(ret);
+}
+
+static int ps_raw_event(struct hid_device *hdev, struct hid_report *report,
+		u8 *data, int size)
+{
+	struct ps_device *dev = hid_get_drvdata(hdev);
+
+	if (dev && dev->parse_report)
+		return dev->parse_report(dev, report, data, size);
+
+	return 0;
+}
+
+static int ps_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	struct ps_device *dev;
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "parse failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
+	if (ret) {
+		hid_err(hdev, "hw start failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_open(hdev);
+	if (ret) {
+		hid_err(hdev, "hw open failed\n");
+		goto err_stop;
+	}
+
+	if (hdev->product == USB_DEVICE_ID_SONY_PS5_CONTROLLER) {
+		dev = dualsense_create(hdev);
+		if (IS_ERR(dev)) {
+			hid_err(hdev, "Failed to create dualsense.\n");
+			ret = PTR_ERR(dev);
+			goto err_close;
+		}
+	} else {

When would this be possible?

+		hid_err(hdev, "Unhandled device\n");
+		ret = -EINVAL;

Assuming it's possible, I believe `-ENODEV` is a better error code here.

+		goto err_close;
+	}
+
+	return ret;
+
+err_close:
+	hid_hw_close(hdev);
+err_stop:
+	hid_hw_stop(hdev);
+	return ret;
+}
[...]
+static const struct hid_device_id ps_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS5_CONTROLLER),
+		.driver_data = 0 },
[...]

`.driver_data` would be initialized to zero anyways, why is it necessary to do
so explicitly?


[1]: https://www.kernel.org/doc/html/latest/process/coding-style.html


Regards,
Barnabás Pőcze