drivers/input/touchscreen/ipaq-micro-ts.c

Source file repositories/reference/linux-study-clean/drivers/input/touchscreen/ipaq-micro-ts.c

File Facts

System
Linux kernel
Corpus path
drivers/input/touchscreen/ipaq-micro-ts.c
Extension
.c
Size
3707 bytes
Lines
157
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 touchscreen_data {
	struct input_dev *input;
	struct ipaq_micro *micro;
};

static void micro_ts_receive(void *data, int len, unsigned char *msg)
{
	struct touchscreen_data *ts = data;

	if (len == 4) {
		input_report_abs(ts->input, ABS_X,
				 be16_to_cpup((__be16 *) &msg[2]));
		input_report_abs(ts->input, ABS_Y,
				 be16_to_cpup((__be16 *) &msg[0]));
		input_report_key(ts->input, BTN_TOUCH, 1);
		input_sync(ts->input);
	} else if (len == 0) {
		input_report_abs(ts->input, ABS_X, 0);
		input_report_abs(ts->input, ABS_Y, 0);
		input_report_key(ts->input, BTN_TOUCH, 0);
		input_sync(ts->input);
	}
}

static void micro_ts_toggle_receive(struct touchscreen_data *ts, bool enable)
{
	struct ipaq_micro *micro = ts->micro;

	guard(spinlock_irq)(&micro->lock);

	if (enable) {
		micro->ts = micro_ts_receive;
		micro->ts_data = ts;
	} else {
		micro->ts = NULL;
		micro->ts_data = NULL;
	}
}

static int micro_ts_open(struct input_dev *input)
{
	struct touchscreen_data *ts = input_get_drvdata(input);

	micro_ts_toggle_receive(ts, true);

	return 0;
}

static void micro_ts_close(struct input_dev *input)
{
	struct touchscreen_data *ts = input_get_drvdata(input);

	micro_ts_toggle_receive(ts, false);
}

static int micro_ts_probe(struct platform_device *pdev)
{
	struct ipaq_micro *micro = dev_get_drvdata(pdev->dev.parent);
	struct touchscreen_data *ts;
	int error;

	ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
	if (!ts)
		return -ENOMEM;

	ts->micro = micro;

	ts->input = devm_input_allocate_device(&pdev->dev);
	if (!ts->input) {
		dev_err(&pdev->dev, "failed to allocate input device\n");
		return -ENOMEM;
	}

	ts->input->name = "ipaq micro ts";
	ts->input->open = micro_ts_open;
	ts->input->close = micro_ts_close;

	input_set_drvdata(ts->input, ts);

	input_set_capability(ts->input, EV_KEY, BTN_TOUCH);
	input_set_capability(ts->input, EV_ABS, ABS_X);
	input_set_capability(ts->input, EV_ABS, ABS_Y);
	input_set_abs_params(ts->input, ABS_X, 0, 1023, 0, 0);
	input_set_abs_params(ts->input, ABS_Y, 0, 1023, 0, 0);

	error = input_register_device(ts->input);
	if (error) {
		dev_err(&pdev->dev, "error registering touch input\n");
		return error;
	}

Annotation

Implementation Notes