drivers/hid/wacom_wac.c

Source file repositories/reference/linux-study-clean/drivers/hid/wacom_wac.c

File Facts

System
Linux kernel
Corpus path
drivers/hid/wacom_wac.c
Extension
.c
Size
163673 bytes
Lines
5138
Domain
Driver Families
Bucket
drivers/hid
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

if (data[5] & 0x80) {
			wacom->tool[0] = (data[5] & 0x20) ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
			wacom->id[0] = (data[5] & 0x20) ? ERASER_DEVICE_ID : STYLUS_DEVICE_ID;
			input_report_key(input, wacom->tool[0], 1);
			input_report_abs(input, ABS_MISC, wacom->id[0]); /* report tool id */
			input_report_abs(input, ABS_X, get_unaligned_le16(&data[1]));
			input_report_abs(input, ABS_Y, get_unaligned_le16(&data[3]));
			input_report_abs(input, ABS_PRESSURE, (signed char)data[6] + 127);
			input_report_key(input, BTN_TOUCH, ((signed char)data[6] > -127));
			input_report_key(input, BTN_STYLUS, (data[5] & 0x40));
		} else {
			input_report_key(input, wacom->tool[0], 0);
			input_report_abs(input, ABS_MISC, 0); /* report tool id */
			input_report_abs(input, ABS_PRESSURE, -1);
			input_report_key(input, BTN_TOUCH, 0);
		}
		break;

	case 2:
		input_report_key(input, BTN_TOOL_PEN, 1);
		input_report_abs(input, ABS_MISC, STYLUS_DEVICE_ID); /* report tool id */
		input_report_abs(input, ABS_X, get_unaligned_le16(&data[1]));
		input_report_abs(input, ABS_Y, get_unaligned_le16(&data[3]));
		input_report_abs(input, ABS_PRESSURE, (signed char)data[6] + 127);
		input_report_key(input, BTN_TOUCH, ((signed char)data[6] > -80) && !(data[5] & 0x20));
		input_report_key(input, BTN_STYLUS, (data[5] & 0x40));
		break;

	default:
		dev_dbg(input->dev.parent,
			"%s: received unknown report #%d\n", __func__, data[0]);
		return 0;
        }

	return 1;
}

static int wacom_pl_irq(struct wacom_wac *wacom)
{
	struct wacom_features *features = &wacom->features;
	unsigned char *data = wacom->data;
	struct input_dev *input = wacom->pen_input;
	int prox, pressure;

	if (data[0] != WACOM_REPORT_PENABLED) {
		dev_dbg(input->dev.parent,
			"%s: received unknown report #%d\n", __func__, data[0]);
		return 0;
	}

	prox = data[1] & 0x40;

	if (!wacom->id[0]) {
		if ((data[0] & 0x10) || (data[4] & 0x20)) {
			wacom->tool[0] = BTN_TOOL_RUBBER;
			wacom->id[0] = ERASER_DEVICE_ID;
		}
		else {
			wacom->tool[0] = BTN_TOOL_PEN;
			wacom->id[0] = STYLUS_DEVICE_ID;
		}
	}

	/* If the eraser is in prox, STYLUS2 is always set. If we
	 * mis-detected the type and notice that STYLUS2 isn't set
	 * then force the eraser out of prox and let the pen in.
	 */
	if (wacom->tool[0] == BTN_TOOL_RUBBER && !(data[4] & 0x20)) {
		input_report_key(input, BTN_TOOL_RUBBER, 0);
		input_report_abs(input, ABS_MISC, 0);
		input_sync(input);
		wacom->tool[0] = BTN_TOOL_PEN;
		wacom->id[0] = STYLUS_DEVICE_ID;
	}

	if (prox) {
		pressure = (signed char)((data[7] << 1) | ((data[4] >> 2) & 1));
		if (features->pressure_max > 255)
			pressure = (pressure << 1) | ((data[4] >> 6) & 1);
		pressure += (features->pressure_max + 1) / 2;

		input_report_abs(input, ABS_X, data[3] | (data[2] << 7) | ((data[1] & 0x03) << 14));
		input_report_abs(input, ABS_Y, data[6] | (data[5] << 7) | ((data[4] & 0x03) << 14));
		input_report_abs(input, ABS_PRESSURE, pressure);

		input_report_key(input, BTN_TOUCH, data[4] & 0x08);
		input_report_key(input, BTN_STYLUS, data[4] & 0x10);
		/* Only allow the stylus2 button to be reported for the pen tool. */
		input_report_key(input, BTN_STYLUS2, (wacom->tool[0] == BTN_TOOL_PEN) && (data[4] & 0x20));
	}

Annotation

Implementation Notes