/*
   * drivers/mtd/devices/goldfish_nand.c
   *
   * Copyright (C) 2007 Google, Inc.
   * Copyright (C) 2012 Intel, Inc.
   * Copyright (C) 2013 Intel, Inc.
   *
   * 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/io.h>
  #include <linux/device.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/ioport.h>
  #include <linux/vmalloc.h>

  #include <linux/mtd/mtd.h>
  #include <linux/platform_device.h>

  #include <linux/mutex.h>

  #include <linux/goldfish.h>

  #include <asm/div64.h>

  #include <linux/dma-mapping.h>

  
  #include "goldfish_nand_reg.h"
  
  struct goldfish_nand {

  	/* lock protects access to the device registers */

  	struct mutex            lock;

  	unsigned char __iomem  *base;
  	struct cmd_params       *cmd_params;
  	size_t                  mtd_count;
  	struct mtd_info         mtd[0];
  };
  
  static u32 goldfish_nand_cmd_with_params(struct mtd_info *mtd,

  					 enum nand_cmd cmd, u64 addr, u32 len,
  					 void *ptr, u32 *rv)

  {
  	u32 cmdp;
  	struct goldfish_nand *nand = mtd->priv;
  	struct cmd_params *cps = nand->cmd_params;
  	unsigned char __iomem  *base = nand->base;

  	if (!cps)

  		return -1;
  
  	switch (cmd) {
  	case NAND_CMD_ERASE:
  		cmdp = NAND_CMD_ERASE_WITH_PARAMS;
  		break;
  	case NAND_CMD_READ:
  		cmdp = NAND_CMD_READ_WITH_PARAMS;
  		break;
  	case NAND_CMD_WRITE:
  		cmdp = NAND_CMD_WRITE_WITH_PARAMS;
  		break;
  	default:
  		return -1;
  	}
  	cps->dev = mtd - nand->mtd;
  	cps->addr_high = (u32)(addr >> 32);
  	cps->addr_low = (u32)addr;
  	cps->transfer_size = len;

  	cps->data = (unsigned long)ptr;

  	writel(cmdp, base + NAND_COMMAND);
  	*rv = cps->result;
  	return 0;
  }
  
  static u32 goldfish_nand_cmd(struct mtd_info *mtd, enum nand_cmd cmd,

  			     u64 addr, u32 len, void *ptr)

  {
  	struct goldfish_nand *nand = mtd->priv;
  	u32 rv;

  	unsigned char __iomem  *base = nand->base;

  	mutex_lock(&nand->lock);

  	if (goldfish_nand_cmd_with_params(mtd, cmd, addr, len, ptr, &rv)) {
  		writel(mtd - nand->mtd, base + NAND_DEV);
  		writel((u32)(addr >> 32), base + NAND_ADDR_HIGH);
  		writel((u32)addr, base + NAND_ADDR_LOW);
  		writel(len, base + NAND_TRANSFER_SIZE);

  		gf_write_ptr(ptr, base + NAND_DATA, base + NAND_DATA_HIGH);

  		writel(cmd, base + NAND_COMMAND);
  		rv = readl(base + NAND_RESULT);
  	}

  	mutex_unlock(&nand->lock);

  	return rv;
  }
  
  static int goldfish_nand_erase(struct mtd_info *mtd, struct erase_info *instr)
  {
  	loff_t ofs = instr->addr;
  	u32 len = instr->len;

  	s32 rem;

  
  	if (ofs + len > mtd->size)
  		goto invalid_arg;

  	ofs = div_s64_rem(ofs, mtd->writesize, &rem);

  	if (rem)
  		goto invalid_arg;
  	ofs *= (mtd->writesize + mtd->oobsize);
  
  	if (len % mtd->writesize)
  		goto invalid_arg;
  	len = len / mtd->writesize * (mtd->writesize + mtd->oobsize);
  
  	if (goldfish_nand_cmd(mtd, NAND_CMD_ERASE, ofs, len, NULL) != len) {
  		pr_err("goldfish_nand_erase: erase failed, start %llx, len %x, dev_size %llx, erase_size %x
  ",

  		       ofs, len, mtd->size, mtd->erasesize);

  		return -EIO;
  	}
  
  	instr->state = MTD_ERASE_DONE;
  	mtd_erase_callback(instr);
  
  	return 0;
  
  invalid_arg:
  	pr_err("goldfish_nand_erase: invalid erase, start %llx, len %x, dev_size %llx, erase_size %x
  ",

  	       ofs, len, mtd->size, mtd->erasesize);

  	return -EINVAL;
  }
  
  static int goldfish_nand_read_oob(struct mtd_info *mtd, loff_t ofs,

  				  struct mtd_oob_ops *ops)

  {

  	s32 rem;

  
  	if (ofs + ops->len > mtd->size)
  		goto invalid_arg;
  	if (ops->datbuf && ops->len && ops->len != mtd->writesize)
  		goto invalid_arg;
  	if (ops->ooblen + ops->ooboffs > mtd->oobsize)
  		goto invalid_arg;

  	ofs = div_s64_rem(ofs, mtd->writesize, &rem);

  	if (rem)
  		goto invalid_arg;
  	ofs *= (mtd->writesize + mtd->oobsize);
  
  	if (ops->datbuf)
  		ops->retlen = goldfish_nand_cmd(mtd, NAND_CMD_READ, ofs,
  						ops->len, ops->datbuf);
  	ofs += mtd->writesize + ops->ooboffs;
  	if (ops->oobbuf)
  		ops->oobretlen = goldfish_nand_cmd(mtd, NAND_CMD_READ, ofs,
  						ops->ooblen, ops->oobbuf);
  	return 0;
  
  invalid_arg:

  	pr_err("goldfish_nand_read_oob: invalid read, start %llx, len %zx, ooblen %zx, dev_size %llx, write_size %x
  ",

  	       ofs, ops->len, ops->ooblen, mtd->size, mtd->writesize);

  	return -EINVAL;
  }
  
  static int goldfish_nand_write_oob(struct mtd_info *mtd, loff_t ofs,

  				   struct mtd_oob_ops *ops)

  {

  	s32 rem;

  
  	if (ofs + ops->len > mtd->size)
  		goto invalid_arg;
  	if (ops->len && ops->len != mtd->writesize)
  		goto invalid_arg;
  	if (ops->ooblen + ops->ooboffs > mtd->oobsize)
  		goto invalid_arg;

  	ofs = div_s64_rem(ofs, mtd->writesize, &rem);

  	if (rem)
  		goto invalid_arg;
  	ofs *= (mtd->writesize + mtd->oobsize);
  
  	if (ops->datbuf)
  		ops->retlen = goldfish_nand_cmd(mtd, NAND_CMD_WRITE, ofs,
  						ops->len, ops->datbuf);
  	ofs += mtd->writesize + ops->ooboffs;
  	if (ops->oobbuf)
  		ops->oobretlen = goldfish_nand_cmd(mtd, NAND_CMD_WRITE, ofs,
  						ops->ooblen, ops->oobbuf);
  	return 0;
  
  invalid_arg:

  	pr_err("goldfish_nand_write_oob: invalid write, start %llx, len %zx, ooblen %zx, dev_size %llx, write_size %x
  ",

  	       ofs, ops->len, ops->ooblen, mtd->size, mtd->writesize);

  	return -EINVAL;
  }
  
  static int goldfish_nand_read(struct mtd_info *mtd, loff_t from, size_t len,

  			      size_t *retlen, u_char *buf)

  {

  	s32 rem;

  
  	if (from + len > mtd->size)
  		goto invalid_arg;

  	from = div_s64_rem(from, mtd->writesize, &rem);

  	if (rem)
  		goto invalid_arg;
  	from *= (mtd->writesize + mtd->oobsize);
  
  	*retlen = goldfish_nand_cmd(mtd, NAND_CMD_READ, from, len, buf);
  	return 0;
  
  invalid_arg:

  	pr_err("goldfish_nand_read: invalid read, start %llx, len %zx, dev_size %llx, write_size %x
  ",

  	       from, len, mtd->size, mtd->writesize);

  	return -EINVAL;
  }
  
  static int goldfish_nand_write(struct mtd_info *mtd, loff_t to, size_t len,

  			       size_t *retlen, const u_char *buf)

  {

  	s32 rem;

  
  	if (to + len > mtd->size)
  		goto invalid_arg;

  	to = div_s64_rem(to, mtd->writesize, &rem);

  	if (rem)
  		goto invalid_arg;
  	to *= (mtd->writesize + mtd->oobsize);
  
  	*retlen = goldfish_nand_cmd(mtd, NAND_CMD_WRITE, to, len, (void *)buf);
  	return 0;
  
  invalid_arg:

  	pr_err("goldfish_nand_write: invalid write, start %llx, len %zx, dev_size %llx, write_size %x
  ",

  	       to, len, mtd->size, mtd->writesize);

  	return -EINVAL;
  }
  
  static int goldfish_nand_block_isbad(struct mtd_info *mtd, loff_t ofs)
  {

  	s32 rem;

  
  	if (ofs >= mtd->size)
  		goto invalid_arg;

  	ofs = div_s64_rem(ofs, mtd->writesize, &rem);

  	if (rem)
  		goto invalid_arg;
  	ofs *= mtd->erasesize / mtd->writesize;
  	ofs *= (mtd->writesize + mtd->oobsize);
  
  	return goldfish_nand_cmd(mtd, NAND_CMD_BLOCK_BAD_GET, ofs, 0, NULL);
  
  invalid_arg:
  	pr_err("goldfish_nand_block_isbad: invalid arg, ofs %llx, dev_size %llx, write_size %x
  ",

  	       ofs, mtd->size, mtd->writesize);

  	return -EINVAL;
  }
  
  static int goldfish_nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
  {

  	s32 rem;

  
  	if (ofs >= mtd->size)
  		goto invalid_arg;

  	ofs = div_s64_rem(ofs, mtd->writesize, &rem);

  	if (rem)
  		goto invalid_arg;
  	ofs *= mtd->erasesize / mtd->writesize;
  	ofs *= (mtd->writesize + mtd->oobsize);
  
  	if (goldfish_nand_cmd(mtd, NAND_CMD_BLOCK_BAD_SET, ofs, 0, NULL) != 1)
  		return -EIO;
  	return 0;
  
  invalid_arg:
  	pr_err("goldfish_nand_block_markbad: invalid arg, ofs %llx, dev_size %llx, write_size %x
  ",

  	       ofs, mtd->size, mtd->writesize);

  	return -EINVAL;
  }
  
  static int nand_setup_cmd_params(struct platform_device *pdev,

  				 struct goldfish_nand *nand)

  {

  	dma_addr_t dma_handle;

  	unsigned char __iomem  *base = nand->base;

  	nand->cmd_params = dmam_alloc_coherent(&pdev->dev,
  					       sizeof(struct cmd_params),
  					       &dma_handle, GFP_KERNEL);
  	if (!nand->cmd_params) {
  		dev_err(&pdev->dev, "allocate buffer failed
  ");
  		return -ENOMEM;
  	}
  	writel((u32)((u64)dma_handle >> 32), base + NAND_CMD_PARAMS_ADDR_HIGH);
  	writel((u32)dma_handle, base + NAND_CMD_PARAMS_ADDR_LOW);

  	return 0;
  }
  
  static int goldfish_nand_init_device(struct platform_device *pdev,

  				     struct goldfish_nand *nand, int id)

  {
  	u32 name_len;
  	u32 result;
  	u32 flags;

  	unsigned char __iomem  *base = nand->base;
  	struct mtd_info *mtd = &nand->mtd[id];
  	char *name;

  	mutex_lock(&nand->lock);

  	writel(id, base + NAND_DEV);
  	flags = readl(base + NAND_DEV_FLAGS);
  	name_len = readl(base + NAND_DEV_NAME_LEN);
  	mtd->writesize = readl(base + NAND_DEV_PAGE_SIZE);
  	mtd->size = readl(base + NAND_DEV_SIZE_LOW);
  	mtd->size |= (u64)readl(base + NAND_DEV_SIZE_HIGH) << 32;
  	mtd->oobsize = readl(base + NAND_DEV_EXTRA_SIZE);
  	mtd->oobavail = mtd->oobsize;
  	mtd->erasesize = readl(base + NAND_DEV_ERASE_SIZE) /
  			(mtd->writesize + mtd->oobsize) * mtd->writesize;

  	mtd->size = div_s64(mtd->size, mtd->writesize + mtd->oobsize);

  	mtd->size *= mtd->writesize;

  	dev_dbg(&pdev->dev,

  		"goldfish nand dev%d: size %llx, page %d, extra %d, erase %d
  ",

  		       id, mtd->size, mtd->writesize,
  		       mtd->oobsize, mtd->erasesize);

  	mutex_unlock(&nand->lock);

  
  	mtd->priv = nand;

  	name = devm_kzalloc(&pdev->dev, name_len + 1, GFP_KERNEL);

  	if (!name)

  		return -ENOMEM;

  	mtd->name = name;

  
  	result = goldfish_nand_cmd(mtd, NAND_CMD_GET_DEV_NAME, 0, name_len,

  				   name);

  	if (result != name_len) {

  		dev_err(&pdev->dev,

  			"goldfish_nand_init_device failed to get dev name %d != %d
  ",
  			       result, name_len);
  		return -ENODEV;
  	}

  	((char *)mtd->name)[name_len] = '\0';

  
  	/* Setup the MTD structure */
  	mtd->type = MTD_NANDFLASH;
  	mtd->flags = MTD_CAP_NANDFLASH;
  	if (flags & NAND_DEV_FLAG_READ_ONLY)
  		mtd->flags &= ~MTD_WRITEABLE;
  	if (flags & NAND_DEV_FLAG_CMD_PARAMS_CAP)
  		nand_setup_cmd_params(pdev, nand);
  
  	mtd->owner = THIS_MODULE;
  	mtd->_erase = goldfish_nand_erase;
  	mtd->_read = goldfish_nand_read;
  	mtd->_write = goldfish_nand_write;
  	mtd->_read_oob = goldfish_nand_read_oob;
  	mtd->_write_oob = goldfish_nand_write_oob;
  	mtd->_block_isbad = goldfish_nand_block_isbad;
  	mtd->_block_markbad = goldfish_nand_block_markbad;
  
  	if (mtd_device_register(mtd, NULL, 0))
  		return -EIO;
  
  	return 0;
  }
  
  static int goldfish_nand_probe(struct platform_device *pdev)
  {
  	u32 num_dev;
  	int i;
  	int err;
  	u32 num_dev_working;
  	u32 version;
  	struct resource *r;
  	struct goldfish_nand *nand;
  	unsigned char __iomem  *base;
  
  	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);

  	if (!r)

  		return -ENODEV;
  
  	base = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);

  	if (!base)

  		return -ENOMEM;
  
  	version = readl(base + NAND_VERSION);
  	if (version != NAND_VERSION_CURRENT) {

  		dev_err(&pdev->dev,

  			"goldfish_nand_init: version mismatch, got %d, expected %d
  ",
  				version, NAND_VERSION_CURRENT);
  		return -ENODEV;
  	}
  	num_dev = readl(base + NAND_NUM_DEV);
  	if (num_dev == 0)
  		return -ENODEV;

  	nand = devm_kzalloc(&pdev->dev, sizeof(*nand) +

  				sizeof(struct mtd_info) * num_dev, GFP_KERNEL);

  	if (!nand)

  		return -ENOMEM;

  	mutex_init(&nand->lock);

  	nand->base = base;
  	nand->mtd_count = num_dev;
  	platform_set_drvdata(pdev, nand);
  
  	num_dev_working = 0;
  	for (i = 0; i < num_dev; i++) {
  		err = goldfish_nand_init_device(pdev, nand, i);
  		if (err == 0)
  			num_dev_working++;
  	}
  	if (num_dev_working == 0)
  		return -ENODEV;
  	return 0;
  }
  
  static int goldfish_nand_remove(struct platform_device *pdev)
  {
  	struct goldfish_nand *nand = platform_get_drvdata(pdev);
  	int i;

  	for (i = 0; i < nand->mtd_count; i++) {
  		if (nand->mtd[i].name)
  			mtd_device_unregister(&nand->mtd[i]);
  	}
  	return 0;
  }
  
  static struct platform_driver goldfish_nand_driver = {
  	.probe		= goldfish_nand_probe,
  	.remove		= goldfish_nand_remove,
  	.driver = {
  		.name = "goldfish_nand"
  	}
  };
  
  module_platform_driver(goldfish_nand_driver);
  MODULE_LICENSE("GPL");