/*
 * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * 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 <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/slab.h>

#include <linux/mmc/core.h>
#include <linux/mmc/card.h>
#include <linux/mmc/sdio_func.h>

#include "gdm_sdio.h"

#define TYPE_A_HEADER_SIZE	4
#define TYPE_A_LOOKAHEAD_SIZE   16
#define YMEM0_SIZE			0x8000	/* 32kbytes */
#define DOWNLOAD_SIZE		(YMEM0_SIZE - TYPE_A_HEADER_SIZE)

#define KRN_PATH	"/lib/firmware/gdm72xx/gdmskrn.bin"
#define RFS_PATH	"/lib/firmware/gdm72xx/gdmsrfs.bin"

static u8 *tx_buf;

static int ack_ready(struct sdio_func *func)
{
	unsigned long start = jiffies;
	u8 val;
	int ret;

	while ((jiffies - start) < HZ) {
		val = sdio_readb(func, 0x13, &ret);
		if (val & 0x01)
			return 1;
		schedule();
	}

	return 0;
}

static int download_image(struct sdio_func *func, char *img_name)
{
	int ret = 0, len, size, pno;
	struct file *filp = NULL;
	struct inode *inode = NULL;
	u8 *buf = tx_buf;
	loff_t pos = 0;

	filp = filp_open(img_name, O_RDONLY | O_LARGEFILE, 0);
	if (IS_ERR(filp)) {
		printk(KERN_ERR "Can't find %s.\n", img_name);
		return -ENOENT;
	}

	inode = filp->f_dentry->d_inode;
	if (!S_ISREG(inode->i_mode)) {
		printk(KERN_ERR "Invalid file type: %s\n", img_name);
		ret = -EINVAL;
		goto out;
	}

	size = i_size_read(inode->i_mapping->host);
	if (size <= 0) {
		printk(KERN_ERR "Unable to find file size: %s\n", img_name);
		ret = size;
		goto out;
	}

	pno = 0;
	while ((len = filp->f_op->read(filp, buf + TYPE_A_HEADER_SIZE,
					DOWNLOAD_SIZE, &pos))) {
		if (len < 0) {
			ret = -1;
			goto out;
		}

		buf[0] = len & 0xff;
		buf[1] = (len >> 8) & 0xff;
		buf[2] = (len >> 16) & 0xff;

		if (pos >= size)	/* The last packet */
			buf[3] = 2;
		else
			buf[3] = 0;

		ret = sdio_memcpy_toio(func, 0, buf, len + TYPE_A_HEADER_SIZE);
		if (ret < 0) {
			printk(KERN_ERR "gdmwm: send image error: "
				"packet number = %d ret = %d\n", pno, ret);
			goto out;
		}
		if (buf[3] == 2)	/* The last packet */
			break;
		if (!ack_ready(func)) {
			ret = -EIO;
			printk(KERN_ERR "gdmwm: Ack is not ready.\n");
			goto out;
		}
		ret = sdio_memcpy_fromio(func, buf, 0, TYPE_A_LOOKAHEAD_SIZE);
		if (ret < 0) {
			printk(KERN_ERR "gdmwm: receive ack error: "
				"packet number = %d ret = %d\n", pno, ret);
			goto out;
		}
		sdio_writeb(func, 0x01, 0x13, &ret);
		sdio_writeb(func, 0x00, 0x10, &ret);	/* PCRRT */

		pno++;
	}
out:
	filp_close(filp, NULL);
	return ret;
}

int sdio_boot(struct sdio_func *func)
{
	static mm_segment_t fs;
	int ret;

	tx_buf = kmalloc(YMEM0_SIZE, GFP_KERNEL);
	if (tx_buf == NULL) {
		printk(KERN_ERR "Error: kmalloc: %s %d\n", __func__, __LINE__);
		return -ENOMEM;
	}

	fs = get_fs();
	set_fs(get_ds());

	ret = download_image(func, KRN_PATH);
	if (ret)
		goto restore_fs;
	printk(KERN_INFO "GCT: Kernel download success.\n");

	ret = download_image(func, RFS_PATH);
	if (ret)
		goto restore_fs;
	printk(KERN_INFO "GCT: Filesystem download success.\n");

restore_fs:
	set_fs(fs);
	kfree(tx_buf);
	return ret;
}