drivers/input/joystick/iforce/iforce-packets.c

Source file repositories/reference/linux-study-clean/drivers/input/joystick/iforce/iforce-packets.c

File Facts

System
Linux kernel
Corpus path
drivers/input/joystick/iforce/iforce-packets.c
Extension
.c
Size
5193 bytes
Lines
206
Domain
Driver Families
Bucket
drivers/input
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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

if (CIRC_SPACE(head, tail, XMIT_SIZE) < n + 2) {
			dev_warn(&iforce->dev->dev,
				 "not enough space in xmit buffer to send new packet\n");
			return -1;
		}

		empty = head == tail;
		XMIT_INC(iforce->xmit.head, n + 2);

/*
 * Store packet in xmit buffer
 */
		iforce->xmit.buf[head] = HI(cmd);
		XMIT_INC(head, 1);
		iforce->xmit.buf[head] = LO(cmd);
		XMIT_INC(head, 1);

		c = CIRC_SPACE_TO_END(head, tail, XMIT_SIZE);
		if (n < c)
			c = n;

		memcpy(&iforce->xmit.buf[head], data, c);
		if (n != c)
			memcpy(&iforce->xmit.buf[0], data + c, n - c);

		XMIT_INC(head, n);
	}

/*
 * If necessary, start the transmission
 */
	if (empty)
		iforce->xport_ops->xmit(iforce);

	return 0;
}
EXPORT_SYMBOL(iforce_send_packet);

/* Start or stop an effect */
int iforce_control_playback(struct iforce* iforce, u16 id, unsigned int value)
{
	unsigned char data[3];

	data[0] = LO(id);
	data[1] = (value > 0) ? ((value > 1) ? 0x41 : 0x01) : 0;
	data[2] = LO(value);
	return iforce_send_packet(iforce, FF_CMD_PLAY, data);
}

/* Mark an effect that was being updated as ready. That means it can be updated
 * again */
static int mark_core_as_ready(struct iforce *iforce, unsigned short addr)
{
	int i;

	if (!iforce->dev->ff)
		return 0;

	for (i = 0; i < iforce->dev->ff->max_effects; ++i) {
		if (test_bit(FF_CORE_IS_USED, iforce->core_effects[i].flags) &&
		    (iforce->core_effects[i].mod1_chunk.start == addr ||
		     iforce->core_effects[i].mod2_chunk.start == addr)) {
			clear_bit(FF_CORE_UPDATE, iforce->core_effects[i].flags);
			return 0;
		}
	}
	dev_warn(&iforce->dev->dev, "unused effect %04x updated !!!\n", addr);
	return -1;
}

static void iforce_report_hats_buttons(struct iforce *iforce, u8 *data)
{
	struct input_dev *dev = iforce->dev;
	int i;

	input_report_abs(dev, ABS_HAT0X, iforce_hat_to_axis[data[6] >> 4].x);
	input_report_abs(dev, ABS_HAT0Y, iforce_hat_to_axis[data[6] >> 4].y);

	for (i = 0; iforce->type->btn[i] >= 0; i++)
		input_report_key(dev, iforce->type->btn[i],
				 data[(i >> 3) + 5] & (1 << (i & 7)));

	/* If there are untouched bits left, interpret them as the second hat */
	if (i <= 8) {
		u8 btns = data[6];

		if (test_bit(ABS_HAT1X, dev->absbit)) {
			if (btns & BIT(3))
				input_report_abs(dev, ABS_HAT1X, -1);
			else if (btns & BIT(1))

Annotation

Implementation Notes