/*
 *   Cypress bootloader driver
 *   Firmware update support for Cypress based devices
 *
 *   Copyright (C) 2009 Michael Buesch <m@bues.ch>
 *
 *   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.
 */

#include "cypress_bootloader.h"
#include "razer_private.h"


struct cypress_command {
	be16_t command;
	uint8_t key[8];
	uint8_t payload[54];
} _packed;

#define CYPRESS_CMD_ENTERBL	cpu_to_be16(0xFF38) /* Enter bootloader */
#define CYPRESS_CMD_WRITEFL	cpu_to_be16(0xFF39) /* Write flash */
#define CYPRESS_CMD_VERIFYFL	cpu_to_be16(0xFF3A) /* Verify flash */
#define CYPRESS_CMD_EXITBL	cpu_to_be16(0xFF3B) /* Exit bootloader */
#define CYPRESS_CMD_UPCHK	cpu_to_be16(0xFF3C) /* Update checksum */

struct cypress_status {
	uint8_t status0;
	uint8_t status1;
	uint8_t _padding[62];
} _packed;

#define CYPRESS_STAT_BLMODE	0x20 /* Bootload mode (success) */
#define CYPRESS_STAT_BOOTOK	0x01 /* Boot completed OK */
#define CYPRESS_STAT_IMAGERR	0x02 /* Image verify error */
#define CYPRESS_STAT_FLCHK	0x04 /* Flash checksum error */
#define CYPRESS_STAT_FLPROT	0x08 /* Flash protection error */
#define CYPRESS_STAT_COMCHK	0x10 /* Communication checksum error */
#define CYPRESS_STAT_INVALKEY	0x40 /* Invalid bootloader key */
#define CYPRESS_STAT_INVALCMD	0x80 /* Invalid command error */
#define CYPRESS_STAT_ALL	0xFF


static void cypress_print_one_status(int *ctx, char *buf, const char *message)
{
	if (*ctx)
		strcat(buf, ", ");
	strcat(buf, message);
	(*ctx)++;
}

static void cypress_print_status(uint8_t status, int error)
{
	char buf[512] = { 0, }; /* big enough for all messages */
	int ctx = 0;

	if (!(status & CYPRESS_STAT_BLMODE))
		cypress_print_one_status(&ctx, buf, "Not in bootloader mode");
	if (status & CYPRESS_STAT_IMAGERR)
		cypress_print_one_status(&ctx, buf, "Image verify error");
	if (status & CYPRESS_STAT_FLCHK)
		cypress_print_one_status(&ctx, buf, "Flash checksum error");
	if (status & CYPRESS_STAT_FLPROT)
		cypress_print_one_status(&ctx, buf, "Flash protection error");
	if (status & CYPRESS_STAT_COMCHK)
		cypress_print_one_status(&ctx, buf, "Communication checksum error");
	if (status & CYPRESS_STAT_INVALKEY)
		cypress_print_one_status(&ctx, buf, "Invalid bootloader key");
	if (status & CYPRESS_STAT_INVALCMD)
		cypress_print_one_status(&ctx, buf, "Invalid command");

	if (error)
		razer_error("Bootloader status: %s\n", buf);
	else
		razer_info("Bootloader status: %s\n", buf);
}

static void cmd_checksum(struct cypress_command *_cmd)
{
	char *cmd = (char *)_cmd;
	unsigned int i, sum = 0;

	for (i = 0; i < 45; i++)
		sum += cmd[i];
	cmd[45] = sum & 0xFF;
}

static int cypress_send_command(struct cypress *c,
				struct cypress_command *command,
				size_t command_size, uint8_t status_mask)
{
	struct cypress_status status;
	int err, transferred;
	uint8_t stat;

	cmd_checksum(command);

razer_dump("cypress command", command, sizeof(*command));
	err = libusb_bulk_transfer(c->usb.h, c->ep_out,
				   (unsigned char *)command, command_size,
				   &transferred, RAZER_USB_TIMEOUT);
	if (err || transferred < 0 || (size_t)transferred != command_size) {
		razer_error("cypress: Failed to send command 0x%02X\n",
			    be16_to_cpu(command->command));
		return -1;
	}
	razer_msleep(100);
	err = libusb_bulk_transfer(c->usb.h, c->ep_in,
				   (unsigned char *)&status, sizeof(status),
				   &transferred, RAZER_USB_TIMEOUT);
	if (err || transferred != sizeof(status)) {
		razer_error("cypress: Failed to receive status report\n");
		return -1;
	}
	status_mask |= CYPRESS_STAT_BLMODE; /* Always check the blmode bit */
	status_mask &= ~CYPRESS_STAT_BOOTOK; /* Always ignore the bootok bit */
	stat = (status.status0 | status.status1) & status_mask;
	if (stat != CYPRESS_STAT_BLMODE) {
		razer_error("cypress: Command 0x%04X failed with "
			    "status0=0x%02X status1=0x%02X\n",
			    be16_to_cpu(command->command),
			    status.status0, status.status1);
		cypress_print_status(stat, 1);
		return -1;
	}

	return 0;
}

static void cypress_assign_default_key(uint8_t *key)
{
	unsigned int i;

	for (i = 0; i < 8; i++)
		key[i] = i;
}

static int cypress_cmd_enterbl(struct cypress *c)
{
	struct cypress_command cmd;

	memset(&cmd, 0, sizeof(cmd));
	cmd.command = CYPRESS_CMD_ENTERBL;
	c->assign_key(cmd.key);

	return cypress_send_command(c, &cmd, sizeof(cmd),
				    CYPRESS_STAT_INVALKEY |
				    CYPRESS_STAT_INVALCMD);
}

static int cypress_cmd_exitbl(struct cypress *c)
{
	struct cypress_command cmd;

	memset(&cmd, 0, sizeof(cmd));
	cmd.command = CYPRESS_CMD_EXITBL;
	c->assign_key(cmd.key);

	return cypress_send_command(c, &cmd, sizeof(cmd),
				    CYPRESS_STAT_ALL);
}

static int cypress_cmd_verifyfl(struct cypress *c)
{
	struct cypress_command cmd;

	memset(&cmd, 0, sizeof(cmd));
	cmd.command = CYPRESS_CMD_VERIFYFL;
	c->assign_key(cmd.key);

	return cypress_send_command(c, &cmd, sizeof(cmd),
				    CYPRESS_STAT_ALL);
}

static int cypress_cmd_updatechksum(struct cypress *c)
{
	struct cypress_command cmd;

	memset(&cmd, 0, sizeof(cmd));
	cmd.command = CYPRESS_CMD_UPCHK;
	c->assign_key(cmd.key);

	return cypress_send_command(c, &cmd, sizeof(cmd),
				    CYPRESS_STAT_ALL);
}

static int cypress_cmd_writefl(struct cypress *c, uint16_t blocknr,
			       uint8_t segment, const char *data)
{
	struct cypress_command cmd;

	memset(&cmd, 0, sizeof(cmd));
	cmd.command = CYPRESS_CMD_WRITEFL;
	c->assign_key(cmd.key);

	cmd.payload[0] = blocknr >> 8;
	cmd.payload[1] = blocknr;
	cmd.payload[2] = segment;
	memcpy(&cmd.payload[3], data, 32);

	return cypress_send_command(c, &cmd, sizeof(cmd),
				    CYPRESS_STAT_ALL);
}

static int cypress_writeflash(struct cypress *c,
			      const char *image, size_t len)
{
	unsigned int block;
	int err;

	if (len % 64) {
		razer_error("cypress_writeflash: internal error\n");
		return -EINVAL;
	}

	for (block = 0; block < len / 64; block++) {
		/* First 32 bytes */
		err = cypress_cmd_writefl(c, block, 0, image);
		if (err) {
			razer_error("cypress: Failed to write image "
				    "(block %u, segment 0)\n", block);
			return -EIO;
		}
		image += 32;
		/* Last 32 bytes */
		err = cypress_cmd_writefl(c, block, 1, image);
		if (err) {
			razer_error("cypress: Failed to write image "
				    "(block %u, segment 1)\n", block);
			return -EIO;
		}
		image += 32;
	}

	return 0;
}

int cypress_open(struct cypress *c, struct libusb_device *dev,
		 void (*assign_key)(uint8_t *key))
{
	int err;

	BUILD_BUG_ON(sizeof(struct cypress_command) != 64);
	BUILD_BUG_ON(sizeof(struct cypress_status) != 64);

return -1; //FIXME: Does not work, yet.

	memset(c, 0, sizeof(*c));
	if (!assign_key)
		assign_key = cypress_assign_default_key;
	c->assign_key = assign_key;

	c->usb.dev = dev;
	c->usb.bConfigurationValue = 1;
	err = razer_usb_add_used_interface(&c->usb, 0, 0);
	if (err)
		return err;
	err = razer_generic_usb_claim(&c->usb);
	if (err) {
		razer_error("cypress: Failed to open and claim device\n");
		return err;
	}

	/* EP numbers are hardcoded */
	c->ep_in = 0x81;
	c->ep_out = 0x02;

	return 0;
}

void cypress_close(struct cypress *c)
{
	razer_generic_usb_release(&c->usb);
	memset(c, 0, sizeof(*c));
}

int cypress_upload_image(struct cypress *c,
			 const char *image, size_t len)
{
	int err;
	int result = 0;

	if (len % 64) {
		razer_error("cypress: Image size is not a multiple "
			    "of the block size (64)\n");
		return -EINVAL;
	}

razer_dump("image", image, len);
	err = cypress_cmd_enterbl(c);
	if (err) {
		razer_error("cypress: Failed to enter bootloader\n");
		result = err;
		goto out;
	}
	err = cypress_writeflash(c, image, len);
	if (err) {
		razer_error("cypress: Failed to write flash image\n");
		result = err;
		goto out;
	}
	err = cypress_cmd_verifyfl(c);
	if (err) {
		razer_error("cypress: Failed to verify the flash\n");
		result = err;
		goto out;
	}
	err = cypress_cmd_updatechksum(c);
	if (err) {
		razer_error("cypress: Failed to update the checksum\n");
		result = err;
		goto out;
	}
	err = cypress_cmd_exitbl(c);
	if (err) {
		razer_error("cypress: Failed to exit bootloader\n");
		result = err;
	}
out:

	return result;
}