drivers/hid/hid-saitek.c

Source file repositories/reference/linux-study-clean/drivers/hid/hid-saitek.c

File Facts

System
Linux kernel
Corpus path
drivers/hid/hid-saitek.c
Extension
.c
Size
5472 bytes
Lines
209
Domain
Driver Families
Bucket
drivers/hid
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct saitek_sc {
	unsigned long quirks;
	int mode;
};

static int saitek_probe(struct hid_device *hdev,
		const struct hid_device_id *id)
{
	unsigned long quirks = id->driver_data;
	struct saitek_sc *ssc;
	int ret;

	ssc = devm_kzalloc(&hdev->dev, sizeof(*ssc), GFP_KERNEL);
	if (ssc == NULL) {
		hid_err(hdev, "can't alloc saitek descriptor\n");
		return -ENOMEM;
	}

	ssc->quirks = quirks;
	ssc->mode = -1;

	hid_set_drvdata(hdev, ssc);

	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 const __u8 *saitek_report_fixup(struct hid_device *hdev, __u8 *rdesc,
		unsigned int *rsize)
{
	struct saitek_sc *ssc = hid_get_drvdata(hdev);

	if ((ssc->quirks & SAITEK_FIX_PS1000) && *rsize == 137 &&
			rdesc[20] == 0x09 && rdesc[21] == 0x33 &&
			rdesc[94] == 0x81 && rdesc[95] == 0x03 &&
			rdesc[110] == 0x81 && rdesc[111] == 0x03) {

		hid_info(hdev, "Fixing up Saitek PS1000 report descriptor\n");

		/* convert spurious axis to a "noop" Logical Minimum (0) */
		rdesc[20] = 0x15;
		rdesc[21] = 0x00;

		/* clear constant bit on buttons and d-pad */
		rdesc[95] = 0x02;
		rdesc[111] = 0x02;

	}
	return rdesc;
}

static int saitek_raw_event(struct hid_device *hdev,
		struct hid_report *report, u8 *raw_data, int size)
{
	struct saitek_sc *ssc = hid_get_drvdata(hdev);

	if (ssc->quirks & SAITEK_RELEASE_MODE_RAT7 && size == 7) {
		/* R.A.T.7 uses bits 13, 14, 15 for the mode */
		int mode = -1;
		if (raw_data[1] & 0x01)
			mode = 0;
		else if (raw_data[1] & 0x02)
			mode = 1;
		else if (raw_data[1] & 0x04)
			mode = 2;

		/* clear mode bits */
		raw_data[1] &= ~0x07;

		if (mode != ssc->mode) {
			hid_dbg(hdev, "entered mode %d\n", mode);
			if (ssc->mode != -1) {
				/* use bit 13 as the mode button */
				raw_data[1] |= 0x04;
			}
			ssc->mode = mode;
		}
	} else if (ssc->quirks & SAITEK_RELEASE_MODE_MMO7 && size == 8) {

Annotation

Implementation Notes