/*
 * Copyright 2013 Con Kolivas <kernel@kolivas.org>
 * Copyright 2013 Hashfast Inc.
 *
 * 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.
 */

#include "config.h"

#include <stdbool.h>

#include "usbutils.h"

#include "driver-hashfast.h"

////////////////////////////////////////////////////////////////////////////////
// Support for the CRC's used in header (CRC-8) and packet body (CRC-32)
////////////////////////////////////////////////////////////////////////////////

#define GP8  0x107   /* x^8 + x^2 + x + 1 */
#define DI8  0x07

static unsigned char crc8_table[256];	/* CRC-8 table */

static void hf_init_crc8(void)
{
	int i,j;
	unsigned char crc;

	for (i = 0; i < 256; i++) {
		crc = i;
		for (j = 0; j < 8; j++)
			crc = (crc << 1) ^ ((crc & 0x80) ? DI8 : 0);
		crc8_table[i] = crc & 0xFF;
	}
}

static unsigned char __maybe_unused hf_crc8(unsigned char *h)
{
	int i;
	unsigned char crc;

	h++;	// Preamble not included
	for (i = 1, crc = 0xff; i < 7; i++)
		crc = crc8_table[crc ^ *h++];

	return crc;
}

struct hf_cmd {
	int cmd;
	char *cmd_name;
	enum usb_cmds usb_cmd;
};

/* Entries in this array need to align with the actual op values specified
 * in hf_protocol.h */
#define C_NULL C_MAX
static const struct hf_cmd hf_cmds[] = {
	{OP_NULL, "OP_NULL", C_NULL},				// 0
	{OP_ROOT, "OP_ROOT", C_NULL},
	{OP_RESET, "OP_RESET", C_HF_RESET},
	{OP_PLL_CONFIG, "OP_PLL_CONFIG", C_HF_PLL_CONFIG},
	{OP_ADDRESS, "OP_ADDRESS", C_HF_ADDRESS},
	{OP_READDRESS, "OP_READDRESS", C_NULL},
	{OP_HIGHEST, "OP_HIGHEST", C_NULL},
	{OP_BAUD, "OP_BAUD", C_HF_BAUD},
	{OP_UNROOT, "OP_UNROOT", C_NULL},			// 8
	{OP_HASH, "OP_HASH", C_HF_HASH},
	{OP_NONCE, "OP_NONCE", C_HF_NONCE},
	{OP_ABORT, "OP_ABORT", C_HF_ABORT},
	{OP_STATUS, "OP_STATUS", C_HF_STATUS},
	{OP_GPIO, "OP_GPIO", C_NULL},
	{OP_CONFIG, "OP_CONFIG", C_HF_CONFIG},
	{OP_STATISTICS, "OP_STATISTICS", C_HF_STATISTICS},
	{OP_GROUP, "OP_GROUP", C_NULL},				// 16
	{OP_CLOCKGATE, "OP_CLOCKGATE", C_HF_CLOCKGATE},

	{OP_USB_INIT, "OP_USB_INIT", C_HF_USB_INIT},		// 18
	{OP_GET_TRACE, "OP_GET_TRACE", C_NULL},
	{OP_LOOPBACK_USB, "OP_LOOPBACK_USB", C_NULL},
	{OP_LOOPBACK_UART, "OP_LOOPBACK_UART", C_NULL},
	{OP_DFU, "OP_DFU", C_NULL},
	{OP_USB_SHUTDOWN, "OP_USB_SHUTDOWN", C_NULL},
	{OP_DIE_STATUS, "OP_DIE_STATUS", C_HF_DIE_STATUS},	// 24
	{OP_GWQ_STATUS, "OP_GWQ_STATUS", C_HF_GWQ_STATUS},
	{OP_WORK_RESTART, "OP_WORK_RESTART", C_HF_WORK_RESTART},
	{OP_USB_STATS1, "OP_USB_STATS1", C_NULL},
	{OP_USB_GWQSTATS, "OP_USB_GWQSTATS", C_HF_GWQSTATS}
};

#define HF_USB_CMD_OFFSET (128 - 18)
#define HF_USB_CMD(X) (X - HF_USB_CMD_OFFSET)

/* Send an arbitrary frame, consisting of an 8 byte header and an optional
 * packet body. */

static int __maybe_unused hashfast_send_frame(struct cgpu_info *hashfast, uint8_t opcode,
			       uint8_t chip, uint8_t core, uint16_t hdata,
			       uint8_t *data, int len)
{
	int tx_length, ret, amount, id = hashfast->device_id;
	uint8_t packet[256];
	struct hf_header *p = (struct hf_header *)packet;

	p->preamble = HF_PREAMBLE;
	p->operation_code = opcode;
	p->chip_address = chip;
	p->core_address = core;
	p->hdata = htole16(hdata);
	p->data_length = len / 4;
	p->crc8 = hf_crc8(packet);

	if (len)
		memcpy(&packet[sizeof(struct hf_header)], data, len);
	tx_length = sizeof(struct hf_header) + len;

	tx_length = sizeof(struct hf_header);

	ret = usb_write(hashfast, (char *)packet, tx_length, &amount,
			hf_cmds[opcode].usb_cmd);
	if (ret < 0 || amount != tx_length) {
		applog(LOG_ERR, "HF%d: hashfast_send_frame: USB Send error, ret %d amount %d vs. tx_length %d",
		       id, ret, amount, tx_length);
		return 1;
	}
	return 0;
}

static bool hashfast_send_header(struct cgpu_info *hashfast, struct hf_header *h,
				 int cmd)
{
	int amount, ret, len;

	len = sizeof(*h);
	ret = usb_write(hashfast, (char *)h, len, &amount, hf_cmds[cmd].usb_cmd);
	if (ret < 0 || amount != len) {
		applog(LOG_WARNING, "HFA%d: send_header: USB Send error, ret %d amount %d vs. length %d",
		       hashfast->device_id, ret, amount, len);
		return false;
	}
	return true;
}

static bool hashfast_reset(struct cgpu_info *hashfast, struct hashfast_info *info)
{
	struct hf_usb_init_header usb_init, *hu = &usb_init;
	struct hf_usb_init_base *db;
	uint8_t buf[1024];
	struct hf_header *h = (struct hf_header *)buf;
	uint8_t hcrc;
	uint8_t addr;
	uint16_t hdata;

	info->hash_clock_rate = 550;                        // Hash clock rate in Mhz
	// Assemble the USB_INIT request
	memset(hu, 0, sizeof(*hu));
	hu->preamble = HF_PREAMBLE;
	hu->operation_code = OP_USB_INIT;
	hu->protocol = PROTOCOL_GLOBAL_WORK_QUEUE;          // Protocol to use
	hu->hash_clock = info->hash_clock_rate;             // Hash clock rate in Mhz
	hu->crc8 = hf_crc8((uint8_t *)hu);
	applog(LOG_WARNING, "HFA%d: Sending OP_USB_INIT with GWQ protocol specified",
	       hashfast->device_id);

	if (!hashfast_send_header(hashfast, (struct hf_header *)hu, HF_USB_CMD(OP_USB_INIT)))
		return false;

	return true;
}

static bool hashfast_detect_common(struct cgpu_info *hashfast)
{
	struct hashfast_info *info;
	bool ret;

	info = calloc(sizeof(struct hashfast_info), 1);
	if (!info)
		quit(1, "Failed to calloc hashfast_info in hashfast_detect_common");
	hashfast->device_data = info;
	/* hashfast_reset should fill in details for info */
	ret = hashfast_reset(hashfast, info);
	if (!ret) {
		free(info);
		return false;
	}

	info->works = calloc(sizeof(struct work *), HF_NUM_SEQUENCE);
	if (!info->works)
		quit(1, "Failed to calloc info works in hashfast_detect_common");
	return true;
}

static void hashfast_usb_initialise(struct cgpu_info *hashfast)
{
	if (hashfast->usbinfo.nodev)
		return;
	// FIXME Do necessary initialising here
}

static bool hashfast_detect_one_usb(libusb_device *dev, struct usb_find_devices *found)
{
	struct cgpu_info *hashfast;

	hashfast = usb_alloc_cgpu(&hashfast_drv, HASHFAST_MINER_THREADS);
	if (!hashfast)
		quit(1, "Failed to usb_alloc_cgpu hashfast");

	if (!usb_init(hashfast, dev, found)) {
		free(hashfast->device_data);
		hashfast->device_data = NULL;
		hashfast = usb_free_cgpu(hashfast);
		return false;
	}

	hashfast->usbdev->usb_type = USB_TYPE_STD;

	hashfast_usb_initialise(hashfast);

	add_cgpu(hashfast);

	return hashfast_detect_common(hashfast);
}

static void hashfast_detect(bool hotplug)
{
	/* Set up the CRC tables only once. */
	if (!hotplug)
		hf_init_crc8();
	usb_detect(&hashfast_drv, hashfast_detect_one_usb);
}

static bool hashfast_prepare(struct thr_info __maybe_unused *thr)
{
	return true;
}

static int64_t hashfast_scanwork(struct thr_info __maybe_unused *thr)
{
	return 0;
}

static struct api_data *hashfast_api_stats(struct cgpu_info __maybe_unused *cgpu)
{
	return NULL;
}

static void hashfast_init(struct cgpu_info *hashfast)
{
	usb_buffer_enable(hashfast);
}

static void hashfast_shutdown(struct thr_info __maybe_unused *thr)
{
}

struct device_drv hashfast_drv = {
	.drv_id = DRIVER_hashfast,
	.dname = "Hashfast",
	.name = "HFA",
	.drv_detect = hashfast_detect,
	.thread_prepare = hashfast_prepare,
	.hash_work = &hash_driver_work,
	.scanwork = hashfast_scanwork,
	.get_api_stats = hashfast_api_stats,
	.reinit_device = hashfast_init,
	.thread_shutdown = hashfast_shutdown,
};