drivers/input/touchscreen/touchit213.c

Source file repositories/reference/linux-study-clean/drivers/input/touchscreen/touchit213.c

File Facts

System
Linux kernel
Corpus path
drivers/input/touchscreen/touchit213.c
Extension
.c
Size
5600 bytes
Lines
215
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 touchit213 {
	struct input_dev *dev;
	struct serio *serio;
	int idx;
	unsigned char csum;
	unsigned char data[5];
	char phys[32];
};

static irqreturn_t touchit213_interrupt(struct serio *serio,
		unsigned char data, unsigned int flags)
{
	struct touchit213 *touchit213 = serio_get_drvdata(serio);
	struct input_dev *dev = touchit213->dev;

	touchit213->data[touchit213->idx] = data;

	switch (touchit213->idx++) {
	case 0:
		if ((touchit213->data[0] & T213_FORMAT_STATUS_MASK) !=
				T213_FORMAT_STATUS_BYTE) {
			pr_debug("unsynchronized data: 0x%02x\n", data);
			touchit213->idx = 0;
		}
		break;

	case 4:
		touchit213->idx = 0;
		input_report_abs(dev, ABS_X,
			(touchit213->data[1] << 7) | touchit213->data[2]);
		input_report_abs(dev, ABS_Y,
			(touchit213->data[3] << 7) | touchit213->data[4]);
		input_report_key(dev, BTN_TOUCH,
			touchit213->data[0] & T213_FORMAT_TOUCH_BIT);
		input_sync(dev);
		break;
	}

	return IRQ_HANDLED;
}

/*
 * touchit213_disconnect() is the opposite of touchit213_connect()
 */

static void touchit213_disconnect(struct serio *serio)
{
	struct touchit213 *touchit213 = serio_get_drvdata(serio);

	input_get_device(touchit213->dev);
	input_unregister_device(touchit213->dev);
	serio_close(serio);
	serio_set_drvdata(serio, NULL);
	input_put_device(touchit213->dev);
	kfree(touchit213);
}

/*
 * touchit213_connect() is the routine that is called when someone adds a
 * new serio device that supports the Touchright protocol and registers it as
 * an input device.
 */

static int touchit213_connect(struct serio *serio, struct serio_driver *drv)
{
	struct touchit213 *touchit213;
	struct input_dev *input_dev;
	int err;

	touchit213 = kzalloc_obj(*touchit213);
	input_dev = input_allocate_device();
	if (!touchit213 || !input_dev) {
		err = -ENOMEM;
		goto fail1;
	}

	touchit213->serio = serio;
	touchit213->dev = input_dev;
	scnprintf(touchit213->phys, sizeof(touchit213->phys),
		  "%s/input0", serio->phys);

	input_dev->name = "Sahara Touch-iT213 Serial TouchScreen";
	input_dev->phys = touchit213->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->id.vendor = SERIO_TOUCHIT213;
	input_dev->id.product = 0;
	input_dev->id.version = 0x0100;
	input_dev->dev.parent = &serio->dev;
	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

Annotation

Implementation Notes