drivers/input/touchscreen/gunze.c

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

File Facts

System
Linux kernel
Corpus path
drivers/input/touchscreen/gunze.c
Extension
.c
Size
3785 bytes
Lines
170
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 gunze {
	struct input_dev *dev;
	struct serio *serio;
	int idx;
	unsigned char data[GUNZE_MAX_LENGTH];
	char phys[32];
};

static void gunze_process_packet(struct gunze *gunze)
{
	struct input_dev *dev = gunze->dev;

	if (gunze->idx != GUNZE_MAX_LENGTH || gunze->data[5] != ',' ||
		(gunze->data[0] != 'T' && gunze->data[0] != 'R')) {
		printk(KERN_WARNING "gunze.c: bad packet: >%.*s<\n", GUNZE_MAX_LENGTH, gunze->data);
		return;
	}

	input_report_abs(dev, ABS_X, simple_strtoul(gunze->data + 1, NULL, 10));
	input_report_abs(dev, ABS_Y, 1024 - simple_strtoul(gunze->data + 6, NULL, 10));
	input_report_key(dev, BTN_TOUCH, gunze->data[0] == 'T');
	input_sync(dev);
}

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

	if (data == '\r') {
		gunze_process_packet(gunze);
		gunze->idx = 0;
	} else {
		if (gunze->idx < GUNZE_MAX_LENGTH)
			gunze->data[gunze->idx++] = data;
	}
	return IRQ_HANDLED;
}

/*
 * gunze_disconnect() is the opposite of gunze_connect()
 */

static void gunze_disconnect(struct serio *serio)
{
	struct gunze *gunze = serio_get_drvdata(serio);

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

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

static int gunze_connect(struct serio *serio, struct serio_driver *drv)
{
	struct gunze *gunze;
	struct input_dev *input_dev;
	int err;

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

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

	input_dev->name = "Gunze AHL-51S TouchScreen";
	input_dev->phys = gunze->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->id.vendor = SERIO_GUNZE;
	input_dev->id.product = 0x0051;
	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(input_dev, ABS_X, 24, 1000, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 24, 1000, 0, 0);

Annotation

Implementation Notes