drivers/hid/hid-elan.c

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

File Facts

System
Linux kernel
Corpus path
drivers/hid/hid-elan.c
Extension
.c
Size
13460 bytes
Lines
535
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

struct elan_drvdata {
	struct input_dev *input;
	u8 prev_report[ELAN_INPUT_REPORT_SIZE];
	struct led_classdev mute_led;
	u8 mute_led_state;
	u16 max_x;
	u16 max_y;
	u16 res_x;
	u16 res_y;
};

static int is_not_elan_touchpad(struct hid_device *hdev)
{
	if (hid_is_usb(hdev)) {
		struct usb_interface *intf = to_usb_interface(hdev->dev.parent);

		return (intf->altsetting->desc.bInterfaceNumber !=
			ELAN_TP_USB_INTF);
	}

	return 0;
}

static int elan_input_mapping(struct hid_device *hdev, struct hid_input *hi,
			      struct hid_field *field, struct hid_usage *usage,
			      unsigned long **bit, int *max)
{
	if (is_not_elan_touchpad(hdev))
		return 0;

	if (field->report->id == ELAN_SINGLE_FINGER ||
	    field->report->id == ELAN_MT_FIRST_FINGER ||
	    field->report->id == ELAN_MT_SECOND_FINGER ||
	    field->report->id == ELAN_MT_I2C)
		return -1;

	return 0;
}

static int elan_get_device_param(struct hid_device *hdev,
				 unsigned char *dmabuf, unsigned char param)
{
	int ret;

	dmabuf[0] = ELAN_FEATURE_REPORT;
	dmabuf[1] = 0x05;
	dmabuf[2] = 0x03;
	dmabuf[3] = param;
	dmabuf[4] = 0x01;

	ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
				 ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
				 HID_REQ_SET_REPORT);
	if (ret != ELAN_FEATURE_SIZE) {
		hid_err(hdev, "Set report error for parm %d: %d\n", param, ret);
		return ret;
	}

	ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
				 ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
				 HID_REQ_GET_REPORT);
	if (ret != ELAN_FEATURE_SIZE) {
		hid_err(hdev, "Get report error for parm %d: %d\n", param, ret);
		return ret;
	}

	return 0;
}

static unsigned int elan_convert_res(char val)
{
	/*
	 * (value from firmware) * 10 + 790 = dpi
	 * dpi * 10 / 254 = dots/mm
	 */
	return (val * 10 + 790) * 10 / 254;
}

static int elan_get_device_params(struct hid_device *hdev)
{
	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
	unsigned char *dmabuf;
	int ret;

	dmabuf = kmalloc(ELAN_FEATURE_SIZE, GFP_KERNEL);
	if (!dmabuf)
		return -ENOMEM;

	ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_X);
	if (ret)

Annotation

Implementation Notes