drivers/input/touchscreen/hampshire.c

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

File Facts

System
Linux kernel
Corpus path
drivers/input/touchscreen/hampshire.c
Extension
.c
Size
4612 bytes
Lines
185
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 hampshire {
	struct input_dev *dev;
	struct serio *serio;
	int idx;
	unsigned char data[HAMPSHIRE_FORMAT_LENGTH];
	char phys[32];
};

static void hampshire_process_data(struct hampshire *phampshire)
{
	struct input_dev *dev = phampshire->dev;

	if (HAMPSHIRE_FORMAT_LENGTH == ++phampshire->idx) {
		input_report_abs(dev, ABS_X, HAMPSHIRE_GET_XC(phampshire->data));
		input_report_abs(dev, ABS_Y, HAMPSHIRE_GET_YC(phampshire->data));
		input_report_key(dev, BTN_TOUCH,
				 HAMPSHIRE_GET_TOUCHED(phampshire->data));
		input_sync(dev);

		phampshire->idx = 0;
	}
}

static irqreturn_t hampshire_interrupt(struct serio *serio,
		unsigned char data, unsigned int flags)
{
	struct hampshire *phampshire = serio_get_drvdata(serio);

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

	if (HAMPSHIRE_RESPONSE_BEGIN_BYTE & phampshire->data[0])
		hampshire_process_data(phampshire);
	else
		dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n",
			phampshire->data[0]);

	return IRQ_HANDLED;
}

static void hampshire_disconnect(struct serio *serio)
{
	struct hampshire *phampshire = serio_get_drvdata(serio);

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

/*
 * hampshire_connect() is the routine that is called when someone adds a
 * new serio device that supports hampshire protocol and registers it as
 * an input device. This is usually accomplished using inputattach.
 */

static int hampshire_connect(struct serio *serio, struct serio_driver *drv)
{
	struct hampshire *phampshire;
	struct input_dev *input_dev;
	int err;

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

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

	input_dev->name = "Hampshire Serial TouchScreen";
	input_dev->phys = phampshire->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->id.vendor = SERIO_HAMPSHIRE;
	input_dev->id.product = 0;
	input_dev->id.version = 0x0001;
	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(phampshire->dev, ABS_X,
			     HAMPSHIRE_MIN_XC, HAMPSHIRE_MAX_XC, 0, 0);
	input_set_abs_params(phampshire->dev, ABS_Y,
			     HAMPSHIRE_MIN_YC, HAMPSHIRE_MAX_YC, 0, 0);

	serio_set_drvdata(serio, phampshire);

Annotation

Implementation Notes