static ssize_t show_value()

in hid-sensor-custom.c [276:382]

• 99 lines of code
• 19 McCabe index (conditional complexity)

static ssize_t show_value(struct device *dev, struct device_attribute *attr,
			  char *buf)
{
	struct hid_sensor_custom *sensor_inst = dev_get_drvdata(dev);
	struct hid_sensor_hub_attribute_info *attribute;
	int index, usage, field_index;
	char name[HID_CUSTOM_NAME_LENGTH];
	bool feature = false;
	bool input = false;
	int value = 0;

	if (sscanf(attr->attr.name, "feature-%x-%x-%s", &index, &usage,
		   name) == 3) {
		feature = true;
		field_index = index + sensor_inst->input_field_count;
	} else if (sscanf(attr->attr.name, "input-%x-%x-%s", &index, &usage,
		   name) == 3) {
		input = true;
		field_index = index;
	} else
		return -EINVAL;

	if (!strncmp(name, "value", strlen("value"))) {
		u32 report_id;
		int ret;

		attribute = &sensor_inst->fields[field_index].attribute;
		report_id = attribute->report_id;
		if (feature) {
			u8 values[HID_CUSTOM_MAX_FEATURE_BYTES];
			int len = 0;
			u64 value = 0;
			int i = 0;

			ret = sensor_hub_get_feature(sensor_inst->hsdev,
						     report_id,
						     index,
						     sizeof(values), values);
			if (ret < 0)
				return ret;

			while (i < ret) {
				if (i + attribute->size > ret) {
					len += scnprintf(&buf[len],
							PAGE_SIZE - len,
							"%d ", values[i]);
					break;
				}
				switch (attribute->size) {
				case 2:
					value = (u64) *(u16 *)&values[i];
					i += attribute->size;
					break;
				case 4:
					value = (u64) *(u32 *)&values[i];
					i += attribute->size;
					break;
				case 8:
					value = *(u64 *)&values[i];
					i += attribute->size;
					break;
				default:
					value = (u64) values[i];
					++i;
					break;
				}
				len += scnprintf(&buf[len], PAGE_SIZE - len,
						"%lld ", value);
			}
			len += scnprintf(&buf[len], PAGE_SIZE - len, "\n");

			return len;
		} else if (input)
			value = sensor_hub_input_attr_get_raw_value(
						sensor_inst->hsdev,
						sensor_inst->hsdev->usage,
						usage, report_id,
						SENSOR_HUB_SYNC, false);
	} else if (!strncmp(name, "units", strlen("units")))
		value = sensor_inst->fields[field_index].attribute.units;
	else if (!strncmp(name, "unit-expo", strlen("unit-expo")))
		value = sensor_inst->fields[field_index].attribute.unit_expo;
	else if (!strncmp(name, "size", strlen("size")))
		value = sensor_inst->fields[field_index].attribute.size;
	else if (!strncmp(name, "minimum", strlen("minimum")))
		value = sensor_inst->fields[field_index].attribute.
							logical_minimum;
	else if (!strncmp(name, "maximum", strlen("maximum")))
		value = sensor_inst->fields[field_index].attribute.
							logical_maximum;
	else if (!strncmp(name, "name", strlen("name"))) {
		struct hid_custom_usage_desc *usage_desc;

		usage_desc = bsearch(&usage, hid_custom_usage_desc_table,
				     ARRAY_SIZE(hid_custom_usage_desc_table),
				     sizeof(struct hid_custom_usage_desc),
				     usage_id_cmp);
		if (usage_desc)
			return snprintf(buf, PAGE_SIZE, "%s\n",
					usage_desc->desc);
		else
			return sprintf(buf, "not-specified\n");
	 } else
		return -EINVAL;

	return sprintf(buf, "%d\n", value);
}