text: // SPDX-License-Identifier: GPL-2.0+
  /*
   * Copyright (C) 2014 Gateworks Corporation
   * Author: Tim Harvey <tharvey@gateworks.com>
   */
  #include <common.h>
  #include <nand.h>
  #include <malloc.h>
  #include "mxs_nand.h"
  
  static struct mtd_info *mtd;
  static struct nand_chip nand_chip;
  
  static void mxs_nand_command(struct mtd_info *mtd, unsigned int command,
  			     int column, int page_addr)
  {
  	register struct nand_chip *chip = mtd_to_nand(mtd);
  	u32 timeo, time_start;
  
  	/* write out the command to the device */
  	chip->cmd_ctrl(mtd, command, NAND_CLE);
  
  	/* Serially input address */
  	if (column != -1) {
  		chip->cmd_ctrl(mtd, column, NAND_ALE);
  		chip->cmd_ctrl(mtd, column >> 8, NAND_ALE);
  	}
  	if (page_addr != -1) {
  		chip->cmd_ctrl(mtd, page_addr, NAND_ALE);
  		chip->cmd_ctrl(mtd, page_addr >> 8, NAND_ALE);
  		/* One more address cycle for devices > 128MiB */
  		if (chip->chipsize > (128 << 20))
  			chip->cmd_ctrl(mtd, page_addr >> 16, NAND_ALE);
  	}
  	chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0);
  
  	if (command == NAND_CMD_READ0) {
  		chip->cmd_ctrl(mtd, NAND_CMD_READSTART, NAND_CLE);
  		chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0);
  	}
  
  	/* wait for nand ready */
  	ndelay(100);
  	timeo = (CONFIG_SYS_HZ * 20) / 1000;
  	time_start = get_timer(0);
  	while (get_timer(time_start) < timeo) {
  		if (chip->dev_ready(mtd))
  			break;
  	}
  }
  
  #if defined (CONFIG_SPL_NAND_IDENT)
  
  /* Trying to detect the NAND flash using ONFi, JEDEC, and (extended) IDs */
  static int mxs_flash_full_ident(struct mtd_info *mtd)
  {
  	int nand_maf_id, nand_dev_id;
  	struct nand_chip *chip = mtd_to_nand(mtd);
  	struct nand_flash_dev *type;
  
  	type = nand_get_flash_type(mtd, chip, &nand_maf_id, &nand_dev_id, NULL);
  
  	if (IS_ERR(type)) {
  		chip->select_chip(mtd, -1);
  		return PTR_ERR(type);
  	}
  
  	return 0;
  }
  
  #else
  
  /* Trying to detect the NAND flash using ONFi only */
  static int mxs_flash_onfi_ident(struct mtd_info *mtd)
  {
  	register struct nand_chip *chip = mtd_to_nand(mtd);
  	int i;
  	u8 mfg_id, dev_id;
  	u8 id_data[8];
  	struct nand_onfi_params *p = &chip->onfi_params;
  
  	/* Reset the chip */
  	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
  
  	/* Send the command for reading device ID */
  	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
  
  	/* Read manufacturer and device IDs */
  	mfg_id = chip->read_byte(mtd);
  	dev_id = chip->read_byte(mtd);
  
  	/* Try again to make sure */
  	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
  	for (i = 0; i < 8; i++)
  		id_data[i] = chip->read_byte(mtd);
  	if (id_data[0] != mfg_id || id_data[1] != dev_id) {
  		printf("second ID read did not match");
  		return -1;
  	}
  	debug("0x%02x:0x%02x ", mfg_id, dev_id);
  
  	/* read ONFI */
  	chip->onfi_version = 0;
  	chip->cmdfunc(mtd, NAND_CMD_READID, 0x20, -1);
  	if (chip->read_byte(mtd) != 'O' || chip->read_byte(mtd) != 'N' ||
  	    chip->read_byte(mtd) != 'F' || chip->read_byte(mtd) != 'I') {
  		return -2;
  	}
  
  	/* we have ONFI, probe it */
  	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
  	chip->read_buf(mtd, (uint8_t *)p, sizeof(*p));
  	mtd->name = p->model;
  	mtd->writesize = le32_to_cpu(p->byte_per_page);
  	mtd->erasesize = le32_to_cpu(p->pages_per_block) * mtd->writesize;
  	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
  	chip->chipsize = le32_to_cpu(p->blocks_per_lun);
  	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
  	/* Calculate the address shift from the page size */
  	chip->page_shift = ffs(mtd->writesize) - 1;
  	chip->phys_erase_shift = ffs(mtd->erasesize) - 1;
  	/* Convert chipsize to number of pages per chip -1 */
  	chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
  	chip->badblockbits = 8;
  
  	debug("erasesize=%d (>>%d)\n", mtd->erasesize, chip->phys_erase_shift);
  	debug("writesize=%d (>>%d)\n", mtd->writesize, chip->page_shift);
  	debug("oobsize=%d\n", mtd->oobsize);
  	debug("chipsize=%lld\n", chip->chipsize);
  
  	return 0;
  }
  
  #endif /* CONFIG_SPL_NAND_IDENT */
  
  static int mxs_flash_ident(struct mtd_info *mtd)
  {
  	int ret;
  #if defined (CONFIG_SPL_NAND_IDENT)
  	ret = mxs_flash_full_ident(mtd);
  #else
  	ret = mxs_flash_onfi_ident(mtd);
  #endif
  	return ret;
  }
  
  static int mxs_read_page_ecc(struct mtd_info *mtd, void *buf, unsigned int page)
  {
  	register struct nand_chip *chip = mtd_to_nand(mtd);
  	int ret;
  
  	chip->cmdfunc(mtd, NAND_CMD_READ0, 0x0, page);
  	ret = nand_chip.ecc.read_page(mtd, chip, buf, 1, page);
  	if (ret < 0) {
  		printf("read_page failed %d\n", ret);
  		return -1;
  	}
  	return 0;
  }
  
  static int is_badblock(struct mtd_info *mtd, loff_t offs, int allowbbt)
  {
  	register struct nand_chip *chip = mtd_to_nand(mtd);
  	unsigned int block = offs >> chip->phys_erase_shift;
  	unsigned int page = offs >> chip->page_shift;
  
  	debug("%s offs=0x%08x block:%d page:%d\n", __func__, (int)offs, block,
  	      page);
  	chip->cmdfunc(mtd, NAND_CMD_READ0, mtd->writesize, page);
  	memset(chip->oob_poi, 0, mtd->oobsize);
  	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
  
  	return chip->oob_poi[0] != 0xff;
  }
  
  /* setup mtd and nand structs and init mxs_nand driver */
  static int mxs_nand_init(void)
  {
  	/* return if already initalized */
  	if (nand_chip.numchips)
  		return 0;
  
  	/* init mxs nand driver */
  	mxs_nand_init_spl(&nand_chip);
  	mtd = nand_to_mtd(&nand_chip);
  	/* set mtd functions */
  	nand_chip.cmdfunc = mxs_nand_command;
  	nand_chip.numchips = 1;
  
  	/* identify flash device */
  	if (mxs_flash_ident(mtd)) {
  		printf("Failed to identify\n");
  		return -1;
  	}
  
  	/* allocate and initialize buffers */
  	nand_chip.buffers = memalign(ARCH_DMA_MINALIGN,
  				     sizeof(*nand_chip.buffers));
  	nand_chip.oob_poi = nand_chip.buffers->databuf + mtd->writesize;
  	/* setup flash layout (does not scan as we override that) */
  	mtd->size = nand_chip.chipsize;
  	nand_chip.scan_bbt(mtd);
  
  	return 0;
  }
  
  int nand_spl_load_image(uint32_t offs, unsigned int size, void *buf)
  {
  	struct nand_chip *chip;
  	unsigned int page;
  	unsigned int nand_page_per_block;
  	unsigned int sz = 0;
  
  	if (mxs_nand_init())
  		return -ENODEV;
  	chip = mtd_to_nand(mtd);
  	page = offs >> chip->page_shift;
  	nand_page_per_block = mtd->erasesize / mtd->writesize;
  
  	debug("%s offset:0x%08x len:%d page:%d\n", __func__, offs, size, page);
  
  	size = roundup(size, mtd->writesize);
  	while (sz < size) {
  		if (mxs_read_page_ecc(mtd, buf, page) < 0)
  			return -1;
  		sz += mtd->writesize;
  		offs += mtd->writesize;
  		page++;
  		buf += mtd->writesize;
  
  		/*
  		 * Check if we have crossed a block boundary, and if so
  		 * check for bad block.
  		 */
  		if (!(page % nand_page_per_block)) {
  			/*
  			 * Yes, new block. See if this block is good. If not,
  			 * loop until we find a good block.
  			 */
  			while (is_badblock(mtd, offs, 1)) {
  				page = page + nand_page_per_block;
  				/* Check i we've reached the end of flash. */
  				if (page >= mtd->size >> chip->page_shift)
  					return -ENOMEM;
  			}
  		}
  	}
  
  	return 0;
  }
  
  int nand_default_bbt(struct mtd_info *mtd)
  {
  	return 0;
  }
  
  void nand_init(void)
  {
  }
  
  void nand_deselect(void)
  {
  }
  
  