/*
 * MTS-IO Controller
 *
 * Copyright (C) 2014 by Multi-Tech Systems
 *
 * Authors: James Maki <jmaki@multitech.com>
 *          Jesse Gilles <jgilles@multitech.com>
 *          Mike Fiore <mfiore@multitech.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <linux/delay.h>
#include <linux/ioctl.h>
#include <linux/input.h>
#include <linux/cdev.h>
#include <linux/clk.h>
#include <linux/sched.h>
#include <linux/reboot.h>
#include <linux/uaccess.h>
#include <linux/gpio.h>
#include <linux/sched.h>
#include <linux/workqueue.h>
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/bitops.h>
#include <linux/spi/spi.h>
#include <linux/i2c/at24.h>
#include <linux/kmod.h>
#include <linux/io.h>
#include <linux/module.h>

#include "mts_io.h"

#define DRIVER_VERSION	"v0.9.1"
#define DRIVER_AUTHOR	"James Maki <jmaki@multitech.com>"
#define DRIVER_DESC	"MTS-IO Controller"
#define DRIVER_NAME	"mts-io"

#define PLATFORM_NAME	"mts-io"

#define LED_LS_CONTROLLABLE		0

/* on-board EEPROM */
extern uint8_t mts_id_eeprom[512];
static struct mts_id_eeprom_layout id_eeprom;

// NUM_AP should be defined from the board code
// it should be set to the value of CONFIG_MTS_NUM_ACCESSORY_PORTS
// arch/arm/mach-at91/board-dt-sam9.c
// if it is 0 or undefined, there is no accessory card support on this HW
#ifdef CONFIG_MTS_NUM_ACCESSORY_PORTS

#ifndef NUM_AP
#define NUM_AP CONFIG_MTS_NUM_ACCESSORY_PORTS
#endif

#else
#define NUM_AP 0
#endif

#if NUM_AP > 0
/* accessory card EEPROMs */
extern uint8_t mts_ap_eeprom[NUM_AP][512];
static struct mts_ap_eeprom_layout ap_eeprom[NUM_AP];
/* kobject pointers for the apX subdirectories that correspond to the accessory ports */
static struct kobject *ap_subdirs[NUM_AP];
/* attribute groups for the accessory ports*/
static struct attribute_group ap_attr_groups[NUM_AP];
#endif

static struct ap_info* port_info[NUM_AP];

static struct platform_device *mts_io_platform_device;
static struct attribute_group *attr_group;
static struct gpio_pin *gpio_pins;

static DEFINE_MUTEX(mts_io_mutex);

/* generic GPIO support */
#include "gpio.c"

/* accessory card support */
#include "mtac.c"
#include "mtac_gpiob.c"
#include "mtac_mfser.c"
#include "mtac_eth.c"

/* reset button handling */
#define RESET_CHECK_PER_SEC		8
#define RESET_INTERVAL		(HZ / RESET_CHECK_PER_SEC)
#define RESET_HOLD_COUNT	(RESET_CHECK_PER_SEC * 3)
#define RESET_LONG_HOLD_COUNT   (RESET_CHECK_PER_SEC * 30)

static pid_t reset_pid = -1;
static pid_t reset_count = 0;
bool sent_extra_long = false;
static int reset_short_signal = SIGUSR1;
static int reset_long_signal = SIGUSR2;
static int reset_extra_long_signal = SIGHUP;
static int reset_short_interval = RESET_HOLD_COUNT;
static int reset_long_interval = RESET_LONG_HOLD_COUNT;

static void reset_callback(struct work_struct *ignored);

static DECLARE_DELAYED_WORK(reset_work, reset_callback);

static void reset_callback(struct work_struct *ignored)
{
	struct gpio_pin *pin;
	int reset_pressed = 0;
	struct pid *vpid = NULL;

	mutex_lock(&mts_io_mutex);

	pin = gpio_pin_by_name("DEVICE_RESET");
	if (pin) {
		reset_pressed = !gpio_get_value(pin->pin.gpio);
	}

	if (reset_pid > 0) {
		vpid = find_vpid(reset_pid);
	}

	if (vpid) {
		if (reset_pressed) {
			reset_count++;
		} else {
			//Reset button has not been pressed
			if (reset_count > 0 && reset_count < reset_short_interval) {
				kill_pid(vpid, reset_short_signal, 1);
			} else if (reset_count >= reset_short_interval && reset_count < reset_long_interval) {
				kill_pid(vpid, reset_long_signal, 1);
			}

			reset_count = 0;
			sent_extra_long = false;
		}
		if (reset_count >= reset_long_interval && ! sent_extra_long) {
			kill_pid(vpid, reset_extra_long_signal, 1);
			sent_extra_long = true;
		}
	} else {
		reset_count = 0;
	}

	mutex_unlock(&mts_io_mutex);

	schedule_delayed_work(&reset_work, RESET_INTERVAL);
}

static ssize_t mts_attr_show_reset_monitor_intervals(struct device *dev, struct device_attribute *attr, char *buf)
{
	int ret;

	mutex_lock(&mts_io_mutex);

	ret = sprintf(buf, "%d %d\n", reset_short_interval / RESET_CHECK_PER_SEC, reset_long_interval / RESET_CHECK_PER_SEC);

	mutex_unlock(&mts_io_mutex);

	return ret;
}

static ssize_t mts_attr_store_reset_monitor_intervals(struct device *dev, struct device_attribute *attr, char *buf, size_t count)
{
	int short_int;
	int long_int;

	if (sscanf(buf, "%i %i", &short_int, &long_int) != 2) {
		return -EINVAL;
	}

	mutex_lock(&mts_io_mutex);

	reset_short_interval = short_int * RESET_CHECK_PER_SEC;
	reset_long_interval = long_int * RESET_CHECK_PER_SEC;

	mutex_unlock(&mts_io_mutex);

	return count;
}

static DEVICE_ATTR_MTS(dev_attr_reset_monitor_intervals, "reset-monitor-intervals",
	mts_attr_show_reset_monitor_intervals, mts_attr_store_reset_monitor_intervals);

static ssize_t mts_attr_show_reset_monitor(struct device *dev,
			struct device_attribute *attr,
			char *buf)
{
	int ret;

	mutex_lock(&mts_io_mutex);

	ret = sprintf(buf, "%d %d %d %d\n", reset_pid, reset_short_signal, reset_long_signal, reset_extra_long_signal);

	mutex_unlock(&mts_io_mutex);

	return ret;
}

static ssize_t mts_attr_store_reset_monitor(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	pid_t pid;
	int short_signal;
	int long_signal;
	int extra_long_signal;
	int result = sscanf(buf, "%i %i %i %i", &pid, &short_signal, &long_signal, &extra_long_signal);

	if (result < 3 || result > 4) {
		return -EINVAL;
	}

        if(result == 3) {
		mutex_lock(&mts_io_mutex);

		reset_pid = pid;
		reset_short_signal = short_signal;
		reset_long_signal = long_signal;

		mutex_unlock(&mts_io_mutex);
	} else {
		mutex_lock(&mts_io_mutex);

		reset_pid = pid;
		reset_short_signal = short_signal;
		reset_long_signal = long_signal;
		reset_extra_long_signal = extra_long_signal;

		mutex_unlock(&mts_io_mutex);
	}

	return count;
}

static DEVICE_ATTR_MTS(dev_attr_reset_monitor, "reset-monitor",
	mts_attr_show_reset_monitor, mts_attr_store_reset_monitor);
static DEVICE_ATTR_RO_MTS(dev_attr_reset, "reset", mts_attr_show_gpio_pin);

/* active-low socket modem reset */
static ssize_t mts_attr_store_radio_reset(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	int value;
	int err;
	struct gpio_pin *pin;

	if (sscanf(buf, "%i", &value) != 1) {
		return -EINVAL;
	}
	if (value != 0) {
		return -EINVAL;
	}

	pin = gpio_pin_by_name("RADIO_RESET");

	if (!pin) {
		return -ENODEV;
	}

	mutex_lock(&mts_io_mutex);

	// 250ms low reset
	err = reset_gpio_pin(pin, 250, 0);

	mutex_unlock(&mts_io_mutex);

	if (err) {
		return err;
	}

	return count;
}

static DEVICE_ATTR_MTS(dev_attr_radio_reset, "radio-reset",
	mts_attr_show_gpio_pin, mts_attr_store_radio_reset);

/* shared gpio attributes */
static DEVICE_ATTR_MTS(dev_attr_radio_power, "radio-power",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);

/* shared gpio-based LEDs */
static DEVICE_ATTR_MTS(dev_attr_led_status, "led-status",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);
static DEVICE_ATTR_MTS(dev_attr_led_a_gpio, "led-a",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);

#if LED_LS_CONTROLLABLE
static DEVICE_ATTR_MTS(dev_attr_led_ls, "led-ls",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);
#else
static DEVICE_ATTR_RO_MTS(dev_attr_led_ls, "led-ls",
	mts_attr_show_gpio_pin);
#endif

static DEVICE_ATTR_MTS(dev_attr_led_b_gpio, "led-b",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);

static DEVICE_ATTR_MTS(dev_attr_led_cd_gpio, "led-cd",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);
static DEVICE_ATTR_MTS(dev_attr_led_c_gpio, "led-c",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);

static DEVICE_ATTR_MTS(dev_attr_led_sig1_gpio, "led-sig1",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);
static DEVICE_ATTR_MTS(dev_attr_led_sig2_gpio, "led-sig2",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);
static DEVICE_ATTR_MTS(dev_attr_led_sig3_gpio, "led-sig3",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);

static DEVICE_ATTR_MTS(dev_attr_led_d_gpio, "led-d",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);
static DEVICE_ATTR_MTS(dev_attr_led_e_gpio, "led-e",
	mts_attr_show_gpio_pin, mts_attr_store_gpio_pin);

/* eeprom info */
static ssize_t mts_attr_show_product_info(struct device *dev,
			struct device_attribute *attr,
			char *buf)
{
	ssize_t value;

	if (strcmp(attr->attr.name, "vendor-id") == 0) {
		value = sprintf(buf, "%.32s\n", id_eeprom.vendor_id);
	} else if (strcmp(attr->attr.name, "product-id") == 0) {
		value = sprintf(buf, "%.32s\n", id_eeprom.product_id);
	} else if (strcmp(attr->attr.name, "device-id") == 0) {
		value = sprintf(buf, "%.32s\n", id_eeprom.device_id);
	} else if (strcmp(attr->attr.name, "hw-version") == 0) {
		value = sprintf(buf, "%.32s\n", id_eeprom.hw_version);
	} else if (strcmp(attr->attr.name, "imei") == 0) {
		value = sprintf(buf, "%.32s\n", id_eeprom.imei);
	} else if (strcmp(attr->attr.name, "mac-eth") == 0) {
		value = sprintf(buf, "%02X:%02X:%02X:%02X:%02X:%02X\n",
			id_eeprom.mac_addr[0],
			id_eeprom.mac_addr[1],
			id_eeprom.mac_addr[2],
			id_eeprom.mac_addr[3],
			id_eeprom.mac_addr[4],
			id_eeprom.mac_addr[5]);
	} else {
		log_error("attribute '%s' not found", attr->attr.name);
		value = -1;
	}

	return value;
}

static DEVICE_ATTR_RO_MTS(dev_attr_vendor_id, "vendor-id",
	mts_attr_show_product_info);
static DEVICE_ATTR_RO_MTS(dev_attr_product_id, "product-id",
	mts_attr_show_product_info);
static DEVICE_ATTR_RO_MTS(dev_attr_device_id, "device-id",
	mts_attr_show_product_info);
static DEVICE_ATTR_RO_MTS(dev_attr_hw_version, "hw-version",
	mts_attr_show_product_info);
static DEVICE_ATTR_RO_MTS(dev_attr_imei, "imei",
	mts_attr_show_product_info);
static DEVICE_ATTR_RO_MTS(dev_attr_eth_mac, "mac-eth",
	mts_attr_show_product_info);

/* include per-device pins and attributes */
#include "mtcdt.c"

static bool load_port(int port) {
	int port_index = port - 1;
	memcpy(&ap_eeprom[port_index], mts_ap_eeprom[port_index], sizeof(mts_ap_eeprom[port_index]));

	if (mts_ap_eeprom[port_index][0] == 0xFF) {
		log_error("uninitialized eeprom on accessory card %d", port);
	} else if (mts_ap_eeprom[port_index][0] == 0x00) {
		log_info("no accessory card inserted in port %d", port);
	} else {
		port_info[port_index] = kzalloc(sizeof(struct ap_info), GFP_KERNEL);
		if (! port_info[port_index]) {
			log_error("alloc of port info failed");
			return false;
		}

		if (strstr(ap_eeprom[port_index].product_id, PRODUCT_ID_MTAC_GPIOB)) {
			if (! set_gpiob_info(port_info[port_index])) {
				log_error("failed to set up gpiob port info");
				return false;
			}
		} else if (strstr(ap_eeprom[port_index].product_id, PRODUCT_ID_MTAC_MFSER)) {
			if (! set_mfser_info(port_info[port_index])) {
				log_error("failed to set up mfser port info");
				return false;
			}
		} else if (strstr(ap_eeprom[port_index].product_id, PRODUCT_ID_MTAC_ETH)) {
			if (! set_eth_info(port_info[port_index])) {
				log_error("failed to set up eth port info");
				return false;
			}
		} else {
			log_error("unknown accessory card [%s] in port %d", ap_eeprom[port_index].product_id, port);
			return false;
		}

		log_info("accessory card %d vendor-id: %.32s", port, ap_eeprom[port_index].vendor_id);
		log_info("accessory card %d product-id: %.32s", port,  ap_eeprom[port_index].product_id);
		log_info("accessory card %d device-id: %.32s", port,  ap_eeprom[port_index].device_id);
		log_info("accessory card %d hw-version: %.32s", port,  ap_eeprom[port_index].hw_version);
		if (strncmp(ap_eeprom[port_index].product_id, PRODUCT_ID_MTAC_ETH, strlen(PRODUCT_ID_MTAC_ETH)) == 0) {
			log_info("accessory card %d mac-addr: %02X:%02X:%02X:%02X:%02X:%02X",
			    port,
			    ap_eeprom[port_index].mac_addr[0],
			    ap_eeprom[port_index].mac_addr[1],
			    ap_eeprom[port_index].mac_addr[2],
			    ap_eeprom[port_index].mac_addr[3],
			    ap_eeprom[port_index].mac_addr[4],
			    ap_eeprom[port_index].mac_addr[5]);
		}

		if (! port_info[port_index]->setup(port)) {
			log_error("accessory port %d setup failed", port);
			port_info[port_index]->teardown(port);
			kfree(port_info[port]);
			return false;
		}
	}

	return true;
}

static void init_accessory_ports(void)
{
	int i;
	for (i = 1; i <= NUM_AP; i++) {
		if (! load_port(i)) {
			log_error("failed to load accessory card in port %d", i);
		}
	}
}

static int mts_id_eeprom_load(void)
{
	memcpy(&id_eeprom, mts_id_eeprom, sizeof(mts_id_eeprom));

	if (mts_id_eeprom[0] == 0xFF) {
		log_error("uninitialized eeprom");
		return -EIO;
	} else {
		attr_group = &mtcdt_platform_attribute_group;
		gpio_pins = gpio_pins_mtcdt_0_0;
		log_info("detected board %s", HW_VERSION_MTCDT_0_0);
	}

	log_info("sizeof: %lu", (unsigned long) sizeof(struct mts_id_eeprom_layout));
	log_info("vendor-id: %.32s", id_eeprom.vendor_id);
	log_info("product-id: %.32s",  id_eeprom.product_id);
	log_info("device-id: %.32s",  id_eeprom.device_id);
	log_info("hw-version: %.32s",  id_eeprom.hw_version);
	log_info("mac-addr: %02X:%02X:%02X:%02X:%02X:%02X",
            id_eeprom.mac_addr[0],
            id_eeprom.mac_addr[1],
            id_eeprom.mac_addr[2],
            id_eeprom.mac_addr[3],
            id_eeprom.mac_addr[4],
            id_eeprom.mac_addr[5]);
	log_info("imei: %.32s",  id_eeprom.imei);
	log_info("capa-gps: %s", DEVICE_CAPA(id_eeprom.capa, CAPA_GPS) ? "yes" : "no");
	log_info("capa-din: %s", DEVICE_CAPA(id_eeprom.capa, CAPA_DIN) ? "yes" : "no");
	log_info("capa-dout: %s", DEVICE_CAPA(id_eeprom.capa, CAPA_DOUT) ? "yes" : "no");
	log_info("capa-adc: %s", DEVICE_CAPA(id_eeprom.capa, CAPA_ADC) ? "yes" : "no");
	log_info("capa-wifi: %s", DEVICE_CAPA(id_eeprom.capa, CAPA_WIFI) ? "yes" : "no");
	log_info("capa-bluetooth: %s", DEVICE_CAPA(id_eeprom.capa, CAPA_BLUETOOTH) ? "yes" : "no");
	if (DEVICE_CAPA(id_eeprom.capa, CAPA_BLUETOOTH)) {
		log_info("mac-bluetooth: %02X:%02X:%02X:%02X:%02X:%02X",
			id_eeprom.mac_bluetooth[0],
			id_eeprom.mac_bluetooth[1],
			id_eeprom.mac_bluetooth[2],
			id_eeprom.mac_bluetooth[3],
			id_eeprom.mac_bluetooth[4],
			id_eeprom.mac_bluetooth[5]);
	}
	if (DEVICE_CAPA(id_eeprom.capa, CAPA_WIFI)) {
		log_info("mac-wifi: %02X:%02X:%02X:%02X:%02X:%02X",
			id_eeprom.mac_wifi[0],
			id_eeprom.mac_wifi[1],
			id_eeprom.mac_wifi[2],
			id_eeprom.mac_wifi[3],
			id_eeprom.mac_wifi[4],
			id_eeprom.mac_wifi[5]);
	}

	return 0;
}

static void cleanup(void)
{
	int port;
	int port_index;

	log_info("cleaning up....");
	if (mts_io_platform_device) {
		platform_device_unregister(mts_io_platform_device);
	}
	for (port_index = 0, port = 1; port_index < NUM_AP; port_index++, port++) {
		if (port_info[port_index]) {
			port_info[port_index]->teardown(port);
			kfree(port_info[port_index]);
		}
	}
	log_info("done cleaning up....");
}

static int __init mts_io_init(void)
{
	struct gpio_pin *pin;
	int ret;
	int port_index;

	log_info("init: " DRIVER_VERSION);
	
	ret = mts_id_eeprom_load();
	if (ret) {
		cleanup();
		return ret;
	}

	mts_io_platform_device = platform_device_alloc(PLATFORM_NAME, -1);
	if (!mts_io_platform_device) {
		cleanup();
		return -ENOMEM;
	}

	ret = platform_device_add(mts_io_platform_device);
	if (ret) {
		cleanup();
		return ret;
	}

	if (NUM_AP) {
		for (port_index = 0; port_index < NUM_AP; port_index++) {
			port_info[port_index] = NULL;
		}
		init_accessory_ports();
	}

	ret = sysfs_create_group(&mts_io_platform_device->dev.kobj, attr_group);
	if (ret) {
		cleanup();
		return ret;
	}

	for (pin = gpio_pins; *pin->name; pin++) {
		ret = gpio_request_one(pin->pin.gpio, pin->pin.flags, pin->pin.label);
		if (ret) {
			log_debug("could not request pin %s (%d) but it could have already been requested under a different pin name", pin->name, ret);
		}
	}

	// start the reset handler
	reset_callback(NULL);

	return 0;
}

static void __exit mts_io_exit(void)
{
	cancel_delayed_work_sync(&reset_work);

	cleanup();

	log_info("exiting");
}

module_init(mts_io_init);
module_exit(mts_io_exit);

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

MODULE_ALIAS("mts-io-ap1-dout");
MODULE_ALIAS("mts-io-ap1-din");
MODULE_ALIAS("mts-io-ap1-adc");
MODULE_ALIAS("mts-io-ap2-dout");
MODULE_ALIAS("mts-io-ap2-din");
MODULE_ALIAS("mts-io-ap2-adc");