/*
 * 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 3 of the License, or (at your option)
 * any later version.  See COPYING for more details.
 */

#ifndef AVALON_H
#define AVALON_H

struct avalon_task {
	uint8_t reset		:1;
	uint8_t flush_fifo	:1;
	uint8_t fan_eft		:1;
	uint8_t timer_eft	:1;
	uint8_t chip_num	:4;
	uint8_t fan_pwm_data;
	uint8_t timeout_data;
	uint8_t miner_num;	// Word[0]

	uint8_t nonce_elf	:1;
	uint32_t miner_ctrl	:31;
	uint32_t pad0;		//Word[2:1]

	uint32_t midstate[8];
	uint32_t data[3];

	// nonce_range: Word[??:14]
} __attribute__((packed));

struct avalon_result {
	uint32_t data[3];
	uint32_t midstate[8];
	uint32_t nonce;
	uint32_t reserved;
} __attribute__((packed));

#define AVALON_GET_WORK_COUNT 1	/* FIXME: should be ~20 */

#define AVALON_MINER_THREADS 1

// The serial I/O speed - Linux uses a define 'B115200' in bits/termios.h
#define AVALON_IO_SPEED 115200

// The size of a successful nonce read
#define AVALON_READ_SIZE 4	/* FIXME: should be 13*4 , the result length */

// Ensure the sizes are correct for the Serial read
#define ASSERT1(condition) __maybe_unused static char sizeof_uint32_t_must_be_4[(condition)?1:-1]
ASSERT1(sizeof(uint32_t) == 4);

#define AVALON_READ_TIME(baud) ((double)AVALON_READ_SIZE * (double)8.0 / (double)(baud))

// Fraction of a second, USB timeout is measured in
// i.e. 10 means 1/10 of a second
#define TIME_FACTOR 10

// It's 10 per second, thus value = 10/TIME_FACTOR = 
#define AVALON_RESET_FAULT_DECISECONDS 1

// In timing mode: Default starting value until an estimate can be obtained
// 5 seconds allows for up to a ~840MH/s device
#define AVALON_READ_COUNT_TIMING	(5 * TIME_FACTOR)

// For a standard Avalon REV3 (to 5 places)
// Since this rounds up a the last digit - it is a slight overestimate
// Thus the hash rate will be a VERY slight underestimate
// (by a lot less than the displayed accuracy)
#define AVALON_REV3_HASH_TIME 0.0000000026316
#define NANOSEC 1000000000.0

// Avalon Rev3 doesn't send a completion message when it finishes
// the full nonce range, so to avoid being idle we must abort the
// work (by starting a new work) shortly before it finishes
//
// Thus we need to estimate 2 things:
//	1) How many hashes were done if the work was aborted
//	2) How high can the timeout be before the Avalon is idle,
//		to minimise the number of work started
//	We set 2) to 'the calculated estimate' - 1
//	to ensure the estimate ends before idle
//
// The simple calculation used is:
//	Tn = Total time in seconds to calculate n hashes
//	Hs = seconds per hash
//	Xn = number of hashes
//	W  = code overhead per work
//
// Rough but reasonable estimate:
//	Tn = Hs * Xn + W	(of the form y = mx + b)
//
// Thus:
//	Line of best fit (using least squares)
//
//	Hs = (n*Sum(XiTi)-Sum(Xi)*Sum(Ti))/(n*Sum(Xi^2)-Sum(Xi)^2)
//	W = Sum(Ti)/n - (Hs*Sum(Xi))/n
//
// N.B. W is less when aborting work since we aren't waiting for the reply
//	to be transferred back (AVALON_READ_TIME)
//	Calculating the hashes aborted at n seconds is thus just n/Hs
//	(though this is still a slight overestimate due to code delays)
//

// Both below must be exceeded to complete a set of data
// Minimum how long after the first, the last data point must be
#define HISTORY_SEC 60
// Minimum how many points a single AVALON_HISTORY should have
#define MIN_DATA_COUNT 5
// The value above used is doubled each history until it exceeds:
#define MAX_MIN_DATA_COUNT 100

// Store the last INFO_HISTORY data sets
// [0] = current data, not yet ready to be included as an estimate
// Each new data set throws the last old set off the end thus
// keeping a ongoing average of recent data
#define INFO_HISTORY 10

struct AVALON_HISTORY {
	struct timeval finish;
	double sumXiTi;
	double sumXi;
	double sumTi;
	double sumXi2;
	uint32_t values;
	uint32_t hash_count_min;
	uint32_t hash_count_max;
};

enum timing_mode { MODE_DEFAULT, MODE_SHORT, MODE_LONG, MODE_VALUE };

struct AVALON_INFO {
	// time to calculate the golden_ob
	uint64_t golden_hashes;
	struct timeval golden_tv;

	struct AVALON_HISTORY history[INFO_HISTORY+1];
	uint32_t min_data_count;

	// seconds per Hash
	double Hs;
	int read_count;

	enum timing_mode timing_mode;
	bool do_avalon_timing;

	double fullnonce;
	int count;
	double W;
	uint32_t values;
	uint64_t hash_count_range;

	// Determine the cost of history processing
	// (which will only affect W)
	uint64_t history_count;
	struct timeval history_time;

	// avalon-options
	int baud;
	int work_division;
	int asic_count;
	uint32_t nonce_mask;
};

#define END_CONDITION 0x0000ffff

#define avalon_open2(devpath, baud, purge)  serial_open(devpath, baud, AVALON_RESET_FAULT_DECISECONDS, purge)
#define avalon_open(devpath, baud)  avalon_open2(devpath, baud, false)

#define AVA_GETS_ERROR -1
#define AVA_GETS_OK 0
#define AVA_GETS_RESTART 1
#define AVA_GETS_TIMEOUT 2

#endif	/* AVALON_H */