drivers/input/joystick/warrior.c

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

File Facts

System
Linux kernel
Corpus path
drivers/input/joystick/warrior.c
Extension
.c
Size
5217 bytes
Lines
201
Domain
Driver Families
Bucket
drivers/input
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 warrior {
	struct input_dev *dev;
	int idx, len;
	unsigned char data[WARRIOR_MAX_LENGTH];
	char phys[32];
};

/*
 * warrior_process_packet() decodes packets the driver receives from the
 * Warrior. It updates the data accordingly.
 */

static void warrior_process_packet(struct warrior *warrior)
{
	struct input_dev *dev = warrior->dev;
	unsigned char *data = warrior->data;

	if (!warrior->idx) return;

	switch ((data[0] >> 4) & 7) {
		case 1:					/* Button data */
			input_report_key(dev, BTN_TRIGGER,  data[3]       & 1);
			input_report_key(dev, BTN_THUMB,   (data[3] >> 1) & 1);
			input_report_key(dev, BTN_TOP,     (data[3] >> 2) & 1);
			input_report_key(dev, BTN_TOP2,    (data[3] >> 3) & 1);
			break;
		case 3:					/* XY-axis info->data */
			input_report_abs(dev, ABS_X, ((data[0] & 8) << 5) - (data[2] | ((data[0] & 4) << 5)));
			input_report_abs(dev, ABS_Y, (data[1] | ((data[0] & 1) << 7)) - ((data[0] & 2) << 7));
			break;
		case 5:					/* Throttle, spinner, hat info->data */
			input_report_abs(dev, ABS_THROTTLE, (data[1] | ((data[0] & 1) << 7)) - ((data[0] & 2) << 7));
			input_report_abs(dev, ABS_HAT0X, (data[3] & 2 ? 1 : 0) - (data[3] & 1 ? 1 : 0));
			input_report_abs(dev, ABS_HAT0Y, (data[3] & 8 ? 1 : 0) - (data[3] & 4 ? 1 : 0));
			input_report_rel(dev, REL_DIAL,  (data[2] | ((data[0] & 4) << 5)) - ((data[0] & 8) << 5));
			break;
	}
	input_sync(dev);
}

/*
 * warrior_interrupt() is called by the low level driver when characters
 * are ready for us. We then buffer them for further processing, or call the
 * packet processing routine.
 */

static irqreturn_t warrior_interrupt(struct serio *serio,
		unsigned char data, unsigned int flags)
{
	struct warrior *warrior = serio_get_drvdata(serio);

	if (data & 0x80) {
		if (warrior->idx) warrior_process_packet(warrior);
		warrior->idx = 0;
		warrior->len = warrior_lengths[(data >> 4) & 7];
	}

	if (warrior->idx < warrior->len)
		warrior->data[warrior->idx++] = data;

	if (warrior->idx == warrior->len) {
		if (warrior->idx) warrior_process_packet(warrior);
		warrior->idx = 0;
		warrior->len = 0;
	}
	return IRQ_HANDLED;
}

/*
 * warrior_disconnect() is the opposite of warrior_connect()
 */

static void warrior_disconnect(struct serio *serio)
{
	struct warrior *warrior = serio_get_drvdata(serio);

	serio_close(serio);
	serio_set_drvdata(serio, NULL);
	input_unregister_device(warrior->dev);
	kfree(warrior);
}

/*
 * warrior_connect() is the routine that is called when someone adds a
 * new serio device. It looks for the Warrior, and if found, registers
 * it as an input device.
 */

static int warrior_connect(struct serio *serio, struct serio_driver *drv)
{

Annotation

Implementation Notes