struct gpio_pin *ap_mfser_pin_by_attr_name(const char *name) {
	struct gpio_pin *pin;
	char *pin_attr_name;

	if (!strcmp(name, "rs4xx-term-res:1")) {
		pin_attr_name = "ap1-gpio3";
	} else if (!strcmp(name, "rts-override:1")) {
		pin_attr_name = "ap1-gpio4";
	} else if (!strcmp(name, "rs4xx-term-res:2")) {
		pin_attr_name = "ap2-gpio3";
	} else if (!strcmp(name, "rts-override:2")) {
		pin_attr_name = "ap2-gpio4";
	} else {
		log_error("accessory card attribute %s not available", name);
		return NULL;
	}

	for (pin = gpio_pins; *pin->name; pin++) {
		if (!strcmp(pin->pin.label, pin_attr_name)) {
			return pin;
		}
	}

	log_error("pin with attr name %s not found", name);

	return NULL;
}


static ssize_t mts_attr_show_ap_mfser_pin(struct kobject *kobj,
			struct kobj_attribute *attr,
			char *buf)
{
	int value;
	struct gpio_pin *pin = ap_mfser_pin_by_attr_name(attr->attr.name);

	if (!pin) {
		return -ENODEV;
	}

	mutex_lock(&mts_io_mutex);

	value = gpio_get_value(pin->pin.gpio);

	mutex_unlock(&mts_io_mutex);

	if (value < 0) {
		return value;
	}

	if (pin->active_low) {
		value = !value;
	}

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

static ssize_t mts_attr_store_ap_mfser_pin(struct kobject *kobj,
		struct kobj_attribute *attr, const char *buf, size_t count)
{
	int value;
	struct gpio_pin *pin = ap_mfser_pin_by_attr_name(attr->attr.name);

	if (!pin) {
		return -ENODEV;
	}

	if (sscanf(buf, "%i", &value) != 1) {
		return -EINVAL;
	}

	if (pin->active_low) {
		value = !value;
	}

	mutex_lock(&mts_io_mutex);

	gpio_set_value(pin->pin.gpio, value);

	mutex_unlock(&mts_io_mutex);

	return count;
}

static ssize_t mts_attr_show_mfser_mode(struct kobject *kobj,
			struct kobj_attribute *attr,
			char *buf)
{
	int ret;
	int modesel0;
	int modesel1;

	struct gpio_pin *pin_modesel0;
	struct gpio_pin *pin_modesel1;

	if (strstr(attr->attr.name, ":1")) {
		pin_modesel0 = gpio_pin_by_name("AP1_GPIO1");
		pin_modesel1 = gpio_pin_by_name("AP1_GPIO2");
	}
	else if (strstr(attr->attr.name, ":2")) {
		pin_modesel0 = gpio_pin_by_name("AP2_GPIO1");
		pin_modesel1 = gpio_pin_by_name("AP2_GPIO2");
	}
	else {
		log_error("unknown serial-mode attr %s", attr->attr.name);
		return -ENODEV;
	}

	if (!pin_modesel0 || !pin_modesel1)
		return -ENODEV;

	mutex_lock(&mts_io_mutex);

	modesel0 = gpio_get_value(pin_modesel0->pin.gpio);
	modesel1 = gpio_get_value(pin_modesel1->pin.gpio);

	if (modesel1 == 0 && modesel0 == 0)
		ret = sprintf(buf, "loopback\n");
	else if (modesel1 == 0 && modesel0 == 1)
		ret = sprintf(buf, "rs232\n");
	else if (modesel1 == 1 && modesel0 == 0)
		ret = sprintf(buf, "rs485-half\n");
	else if (modesel1 == 1 && modesel0 == 1)
		ret = sprintf(buf, "rs422-485-full\n");
	else
		ret = sprintf(buf, "error\n");

	mutex_unlock(&mts_io_mutex);

	return ret;
}

static ssize_t mts_attr_store_mfser_mode(struct kobject *kobj,
		struct kobj_attribute *attr, const char *buf, size_t count)
{
	int modesel0;
	int modesel1;
	struct gpio_pin *pin_modesel0;
	struct gpio_pin *pin_modesel1;

	if (strstr(attr->attr.name, ":1")) {
		pin_modesel0 = gpio_pin_by_name("AP1_GPIO1");
		pin_modesel1 = gpio_pin_by_name("AP1_GPIO2");
	}
	else if (strstr(attr->attr.name, ":2")) {
		pin_modesel0 = gpio_pin_by_name("AP2_GPIO1");
		pin_modesel1 = gpio_pin_by_name("AP2_GPIO2");
	}
	else {
		log_error("unknown serial-mode attr %s", attr->attr.name);
		return -ENODEV;
	}

	if (!pin_modesel0 || !pin_modesel1)
		return -ENODEV;

	if (!strcasecmp(buf, "loopback")) {
		modesel1 = 0;
		modesel0 = 0;
	}
	else if (!strcasecmp(buf, "rs232")) {
		modesel1 = 0;
		modesel0 = 1;
	}
	else if (!strcasecmp(buf, "rs485-half")) {
		modesel1 = 1;
		modesel0 = 0;
	}
	else if (!strcasecmp(buf, "rs422-485-full")) {
		modesel1 = 1;
		modesel0 = 1;
	}
	else  {
		return -EINVAL;
	}

	mutex_lock(&mts_io_mutex);

	gpio_set_value(pin_modesel0->pin.gpio, modesel0);
	gpio_set_value(pin_modesel1->pin.gpio, modesel1);

	mutex_unlock(&mts_io_mutex);

	return count;
}

// 1 serial mode
// 1 rs4xx term resistor
// 1 rts override
// 1 vendor-id
// 1 product-id
// 1 device-id
// 1 hw-version
static int ap_mfser_attrs_size = 7;

static bool mfser_setup(enum ap port) {
	int port_index = port - 1;
	struct kobj_attribute *attr;
	char buf[32];

	log_info("loading MFSER accessory card in port %d", port);

	if (device_attrs_size + ap_mfser_attrs_size >= device_attrs_max_size) {
		log_error("can't load MFSER accessory card in port %d - not enough room for attributes", port);
		return false;
	}

	// mark the attribute indices we're using so we know what to clean up
	port_info[port_index]->attrs_start = device_attrs_size;
	port_info[port_index]->attrs_end = device_attrs_size + ap_mfser_attrs_size;

	sprintf(buf, "serial-mode:%d", port);
	attr = create_attribute(buf, MTS_ATTR_MODE_RW);
	if (! attr) {
		log_error("failed to create attribute[%s]", buf);
		return false;
	}
	attr->show = mts_attr_show_mfser_mode;
	attr->store = mts_attr_store_mfser_mode;
	device_attrs[device_attrs_size++] = &attr->attr;

	sprintf(buf, "rs4xx-term-res:%d", port);
	attr = create_attribute(buf, MTS_ATTR_MODE_RW);
	if (! attr) {
		log_error("failed to create attribute[%s]", buf);
		return false;
	}
	attr->show = mts_attr_show_ap_mfser_pin;
	attr->store = mts_attr_store_ap_mfser_pin;
	device_attrs[device_attrs_size++] = &attr->attr;

	sprintf(buf, "rts-override:%d", port);
	attr = create_attribute(buf, MTS_ATTR_MODE_RW);
	if (! attr) {
		log_error("failed to create attribute[%s]", buf);
		return false;
	}
	attr->show = mts_attr_show_ap_mfser_pin;
	attr->store = mts_attr_store_ap_mfser_pin;
	device_attrs[device_attrs_size++] = &attr->attr;

	// add attributes for eeprom contents
	if (! ap_add_product_info_attributes(port, MTAC_MFSER_0_0)) {
		log_error("failed to add product info attributes");
		return false;
	}

	return true;
}

static bool mfser_teardown(enum ap port) {
	int i;
	int port_index = port - 1;

	log_info("unloading MFSER accessory card in port %d", port);

	// clean up allocated memory for attributes
	for (i = port_info[port_index]->attrs_start; i < port_info[port_index]->attrs_end; i++) {
		if (device_attrs[i]) {
			if (device_attrs[i]->name)
				kfree(device_attrs[i]->name);

			kfree(device_attrs[i]);
		}
	}

	port_info[port_index]->attrs_start = 0;
	port_info[port_index]->attrs_end = 0;

	return true;
}

bool set_mfser_info(struct ap_info* info) {
	info->product_id = MTAC_MFSER_0_0;
	info->setup = &mfser_setup;
	info->teardown = &mfser_teardown;
	info->attrs_start = 0;
	info->attrs_end = 0;

	return true;
}