drivers/input/touchscreen/touchright.c

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

File Facts

System
Linux kernel
Corpus path
drivers/input/touchscreen/touchright.c
Extension
.c
Size
3794 bytes
Lines
175
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 tr {
	struct input_dev *dev;
	struct serio *serio;
	int idx;
	unsigned char data[TR_LENGTH];
	char phys[32];
};

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

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

	if ((tr->data[0] & TR_FORMAT_STATUS_MASK) == TR_FORMAT_STATUS_BYTE) {
		if (++tr->idx == TR_LENGTH) {
			input_report_abs(dev, ABS_X,
				(tr->data[1] << 5) | (tr->data[2] >> 1));
			input_report_abs(dev, ABS_Y,
				(tr->data[3] << 5) | (tr->data[4] >> 1));
			input_report_key(dev, BTN_TOUCH,
				tr->data[0] & TR_FORMAT_TOUCH_BIT);
			input_sync(dev);
			tr->idx = 0;
		}
	}

	return IRQ_HANDLED;
}

/*
 * tr_disconnect() is the opposite of tr_connect()
 */

static void tr_disconnect(struct serio *serio)
{
	struct tr *tr = serio_get_drvdata(serio);

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

/*
 * tr_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 tr_connect(struct serio *serio, struct serio_driver *drv)
{
	struct tr *tr;
	struct input_dev *input_dev;
	int err;

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

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

	input_dev->name = "Touchright Serial TouchScreen";
	input_dev->phys = tr->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->id.vendor = SERIO_TOUCHRIGHT;
	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);
	input_set_abs_params(tr->dev, ABS_X, TR_MIN_XC, TR_MAX_XC, 0, 0);
	input_set_abs_params(tr->dev, ABS_Y, TR_MIN_YC, TR_MAX_YC, 0, 0);

	serio_set_drvdata(serio, tr);

	err = serio_open(serio, drv);
	if (err)
		goto fail2;

	err = input_register_device(tr->dev);

Annotation

Implementation Notes