#define DRIVER_VERSION  "v2.0.0"
#define DRIVER_AUTHOR   "Multi-Tech"
#define DRIVER_DESC "MTS Multi-Fuction Serial Accessory Card"
#define DRIVER_NAME "mtac-mfser"

#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/kmod.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mtac.h>
#include <linux/mts_io.h>
#include <linux/gpio/consumer.h>

static struct gpio_pin gpio_pins_mtac_mfser[] = {
	// gpio pins for Accessory Card 1
	{
		.name = "AP1_GPIO1",
		.pin = {
			.gpio = ~0U,
			.flags = GPIOD_OUT_LOW,
			.label = "ap1-gpio1",
		},
		.active_low = 1,
                .do_gpio_desc = 1,
	},
	{
		.name = "AP1_GPIO2",
		.pin = {
			.gpio =  ~0U,
			.flags = GPIOD_OUT_LOW,
			.label = "ap1-gpio2",
		},
                .do_gpio_desc = 1,
        },
	{
		.name = "AP1_GPIO3",
		.pin = {
			.gpio =  ~0U,
			.flags = GPIOD_OUT_LOW,
			.label = "ap1-gpio3",
		},
                .do_gpio_desc = 1,
	},
	{
		.name = "AP1_GPIO4",
		.pin = {
			.gpio =  ~0U,
			.flags = GPIOD_OUT_LOW,
			.label = "ap1-gpio4",
		},
                .do_gpio_desc = 1,
	},
	

	// gpio pins for Accessory Card 2
	{
		.name = "AP2_GPIO1",
		.pin = {
			.gpio =  ~0U,
			.flags = GPIOD_OUT_LOW,
			.label = "ap2-gpio1",
		},
		.active_low = 1,
                .do_gpio_desc = 1,
	},
	{
		.name = "AP2_GPIO2",
		.pin = {
			.gpio = ~0U,
			.flags = GPIOD_OUT_LOW,
			.label = "ap2-gpio2",
		},
                .do_gpio_desc = 1,
	},
	{
		.name = "AP2_GPIO3",
		.pin = {
			.gpio = ~0U,
			.flags = GPIOD_OUT_LOW,
			.label = "ap2-gpio3",
		},
                .do_gpio_desc = 1,
	},
	{
		.name = "AP2_GPIO4",
		.pin = {
			.gpio = ~0U,
			.flags = GPIOD_OUT_LOW,
			.label = "ap2-gpio4",
		},
                .do_gpio_desc = 1,
	},
	{ },
};

static char* mfser_gpio_pin_name_by_attr_name(const char* name, int port) {
	switch (port) {
		case port_1:
			if (! strcmp(name, "rs4xx-term-res")) {
				return "ap1-gpio3";
			} else if (! strcmp(name, "rts-override")) {
				return "ap1-gpio4";
			} else {
				log_error("attirbute name [%s] is invalid for MFSER in port %d", name, port);
				return "";
			}

		case port_2:
			if (! strcmp(name, "rs4xx-term-res")) {
				return "ap2-gpio3";
			} else if (! strcmp(name, "rts-override")) {
				return "ap2-gpio4";
			} else {
				log_error("attribute name [%s] is invalid for MFSER in port %d", name, port);
				return "";
			}
	}
	return "";
}

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

	struct gpio_pin *pin_modesel0;
	struct gpio_pin *pin_modesel1;

	port = mtac_port_from_kobject(kobj);
	if (port < 0) {
		log_error("mtac_port_from_kobject returned %d", port);
		return -EINVAL;
	}

	port_index = port - 1;
	switch (port) {
		case port_1:
			pin_modesel0 = mtac_gpio_pin_by_name("AP1_GPIO1",port_index);
			pin_modesel1 = mtac_gpio_pin_by_name("AP1_GPIO2",port_index);
			break;

		case port_2:
			pin_modesel0 = mtac_gpio_pin_by_name("AP2_GPIO1",port_index);
			pin_modesel1 = mtac_gpio_pin_by_name("AP2_GPIO2",port_index);
			break;

		default:
			log_error("unknown serial-mode attr [%s]", attr->attr.name);
			return -ENODEV;
	}

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

	mutex_lock(&mtac_mutex);

	modesel0 = gpiod_get_value(pin_modesel0->desc);
	modesel1 = gpiod_get_value(pin_modesel1->desc);

	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(&mtac_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 port;
	int modesel0;
	int modesel1;
	struct gpio_pin *pin_modesel0;
	struct gpio_pin *pin_modesel1;
	int port_index;

	port = mtac_port_from_kobject(kobj);
	if (port < 0) {
		log_error("mtac_port_from_kobject returned %d", port);
		return -EINVAL;
	}

	port_index = port - 1;
	switch (port) {
		case port_1:
			pin_modesel0 = mtac_gpio_pin_by_name("AP1_GPIO1",port_index);
			pin_modesel1 = mtac_gpio_pin_by_name("AP1_GPIO2",port_index);
			break;

		case port_2:
			pin_modesel0 = mtac_gpio_pin_by_name("AP2_GPIO1",port_index);
			pin_modesel1 = mtac_gpio_pin_by_name("AP2_GPIO2",port_index);
			break;

		default:
			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(&mtac_mutex);

	gpiod_set_value(pin_modesel0->desc, modesel0);
	gpiod_set_value(pin_modesel1->desc, modesel1);

	mutex_unlock(&mtac_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
// NULL
static size_t ap_mfser_attrs_size = 8;

static bool mfser_setup(enum ap port) {
	int i;
	int port_index = port - 1;
	int index = 0;
	int count = 0;
	int ret;
	char buf[32];
	struct kobj_attribute* attr;
	struct attribute **attrs;
	struct kobject *subdir;

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

	sprintf(buf, "ap%d", port);
	subdir = kobject_create_and_add(buf, &mts_io_platform_device->dev.kobj);
	if (! subdir) {
		log_error("kobject_create_and_add for MFSER in port %d failed", port);
		return false;
	}

	mtac_set_port_pins(port_index,gpio_pins_mtac_mfser,subdir);

	// create the link to the apX directory this card is in
	// if we're in the first slot, we get plain "mfser"
	// if we're in a different slot, we might need to use "mfser-2" to differentiate
	if (port > 1) {
		for (i = 1; i < port; i++) {
			if (mtac_port_info[i - 1]) {
				if (strstr(mtac_port_info[i - 1]->product_id, PRODUCT_ID_MTAC_MFSER)) {
					count++;
				}
			}
		}
	}
	if (count > 0) {
		sprintf(buf, "mfser-%d", count + 1);
	} else {
		sprintf(buf, "mfser");
	}
	ret = sysfs_create_link(mtac_port_info[port_index]->subdirs->parent, mtac_port_info[port_index]->subdirs, buf);
	if (ret) {
		log_error("failed to link [%s] to [%s], %d", buf, mtac_port_info[port_index]->subdirs->name, ret);
	}

	attrs = kzalloc(sizeof(struct attribute*) * ap_mfser_attrs_size, GFP_KERNEL);
	if (! attrs) {
		log_error("failed to allocate attribute space for port %d", port);
		return false;
	}

	sprintf(buf, "serial-mode");
	attr = mtac_create_attribute(buf, MTS_ATTR_MODE_RW);
	if (! attr) {
		log_error("failed to create attribute [%s] for MFSER in port %d", buf, port);
		return false;
	}
	attr->show = mts_attr_show_mfser_mode;
	attr->store = mts_attr_store_mfser_mode;
	attrs[index++] = &attr->attr;

	sprintf(buf, "rs4xx-term-res");
	attr = mtac_create_attribute(buf, MTS_ATTR_MODE_RW);
	if (! attr) {
		log_error("failed to create attribute [%s] for MFSER in port %d", buf, port);
		return false;
	}
	attr->show = mtac_attr_show_ap_gpio_pin;
	attr->store = mtac_attr_store_ap_gpio_pin;
	attrs[index++] = &attr->attr;

	sprintf(buf, "rts-override");
	attr = mtac_create_attribute(buf, MTS_ATTR_MODE_RW);
	if (! attr) {
		log_error("failed to create attribute [%s] for MFSER in port %d", buf, port);
		return false;
	}
	attr->show = mtac_attr_show_ap_gpio_pin;
	attr->store = mtac_attr_store_ap_gpio_pin;
	attrs[index++] = &attr->attr;

	// add attributes for eeprom contents
	if (! mtac_add_product_info_attributes(port, attrs, &index)) {
		log_error("failed to add product info attributes for MFSER in port %d", port);
		return false;
	}

	attrs[index] = NULL;

	mtac_port_info[port_index]->attr_group.attrs = attrs;
	if (sysfs_create_group(mtac_port_info[port_index]->subdirs, &mtac_port_info[port_index]->attr_group)) {
		log_error("sysfs_create_group failed for MFSER in port %d", port);
		return false;
	}

	return true;
}

static bool mfser_teardown(enum ap port) {
	int i;
	int port_index = port - 1;
	struct attribute **attrs = mtac_port_info[port_index]->attr_group.attrs;

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

	// clean up allocated memory for attributes
	for (i = 0; i < ap_mfser_attrs_size; i++) {
		if (attrs[i]) {
			if (attrs[i]->name)
				kfree(attrs[i]->name);

			kfree(attrs[i]);
		}
	}

	kfree(attrs);

	// clean up our "apX/" kobject if it exists
	if (mtac_port_info[port_index]->subdirs) {
		kobject_put(mtac_port_info[port_index]->subdirs);
	}

	mtac_clear_port_pins(port_index);

	return true;
}

void set_mfser_info(struct ap_info* info) {
	snprintf(info->product_id, 32, "%s", PRODUCT_ID_MTAC_MFSER);
	info->setup = &mfser_setup;
	info->teardown = &mfser_teardown;
	info->gpio_pin_name_by_attr_name = &mfser_gpio_pin_name_by_attr_name;
}

/*
 * Loop through all the slots, and set up the
 * mtac-mfser driver for all slots.
 */
static int __init mtac_mfser_init(void)
{
	int slot_count = 0;

	slot_count = mtac_find(set_mfser_info,PRODUCT_ID_MTAC_MFSER);

	if (slot_count < 1) {
		log_debug("No MTAC MFSER found");
		if (slot_count < 0)
			return slot_count;
		else
			return -ENXIO;

	}

	return 0;
}

/* We can only tear down our own device */
static void __exit mtac_mfser_exit(void)
{
	mtac_free(PRODUCT_ID_MTAC_MFSER,mfser_setup,"mfser");
	log_info("exiting");
}

module_init(mtac_mfser_init);
module_exit(mtac_mfser_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL");