path: root/drivers/mtd/nand/fsmc_nand.c

/*
 * drivers/mtd/nand/fsmc_nand.c
 *
 * ST Microelectronics
 * Flexible Static Memory Controller (FSMC)
 * Driver for NAND portions
 *
 * Copyright © 2010 ST Microelectronics
 * Vipin Kumar <vipin.kumar@st.com>
 * Ashish Priyadarshi
 *
 * Based on drivers/mtd/nand/nomadik_nand.c
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/dmaengine.h>
#include <linux/dma-direction.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/resource.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/mtd/partitions.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/mtd/fsmc.h>
#include <linux/amba/bus.h>
#include <mtd/mtd-abi.h>

static int fsmc_ecc1_ooblayout_ecc(struct mtd_info *mtd, int section,
				   struct mtd_oob_region *oobregion)
{
	struct nand_chip *chip = mtd_to_nand(mtd);

	if (section >= chip->ecc.steps)
		return -ERANGE;

	oobregion->offset = (section * 16) + 2;
	oobregion->length = 3;

	return 0;
}

static int fsmc_ecc1_ooblayout_free(struct mtd_info *mtd, int section,
				    struct mtd_oob_region *oobregion)
{
	struct nand_chip *chip = mtd_to_nand(mtd);

	if (section >= chip->ecc.steps)
		return -ERANGE;

	oobregion->offset = (section * 16) + 8;

	if (section < chip->ecc.steps - 1)
		oobregion->length = 8;
	else
		oobregion->length = mtd->oobsize - oobregion->offset;

	return 0;
}

static const struct mtd_ooblayout_ops fsmc_ecc1_ooblayout_ops = {
	.ecc = fsmc_ecc1_ooblayout_ecc,
	.free = fsmc_ecc1_ooblayout_free,
};

/*
 * ECC placement definitions in oobfree type format.
 * There are 13 bytes of ecc for every 512 byte block and it has to be read
 * consecutively and immediately after the 512 byte data block for hardware to
 * generate the error bit offsets in 512 byte data.
 */
static int fsmc_ecc4_ooblayout_ecc(struct mtd_info *mtd, int section,
				   struct mtd_oob_region *oobregion)
{
	struct nand_chip *chip = mtd_to_nand(mtd);

	if (section >= chip->ecc.steps)
		return -ERANGE;

	oobregion->length = chip->ecc.bytes;

	if (!section && mtd->writesize <= 512)
		oobregion->offset = 0;
	else
		oobregion->offset = (section * 16) + 2;

	return 0;
}

static int fsmc_ecc4_ooblayout_free(struct mtd_info *mtd, int section,
				    struct mtd_oob_region *oobregion)
{
	struct nand_chip *chip = mtd_to_nand(mtd);

	if (section >= chip->ecc.steps)
		return -ERANGE;

	oobregion->offset = (section * 16) + 15;

	if (section < chip->ecc.steps - 1)
		oobregion->length = 3;
	else
		oobregion->length = mtd->oobsize - oobregion->offset;

	return 0;
}

static const struct mtd_ooblayout_ops fsmc_ecc4_ooblayout_ops = {
	.ecc = fsmc_ecc4_ooblayout_ecc,
	.free = fsmc_ecc4_ooblayout_free,
};

/**
 * struct fsmc_nand_data - structure for FSMC NAND device state
 *
 * @pid:		Part ID on the AMBA PrimeCell format
 * @mtd:		MTD info for a NAND flash.
 * @nand:		Chip related info for a NAND flash.
 * @partitions:		Partition info for a NAND Flash.
 * @nr_partitions:	Total number of partition of a NAND flash.
 *
 * @bank:		Bank number for probed device.
 * @clk:		Clock structure for FSMC.
 *
 * @read_dma_chan:	DMA channel for read access
 * @write_dma_chan:	DMA channel for write access to NAND
 * @dma_access_complete: Completion structure
 *
 * @data_pa:		NAND Physical port for Data.
 * @data_va:		NAND port for Data.
 * @cmd_va:		NAND port for Command.
 * @addr_va:		NAND port for Address.
 * @regs_va:		FSMC regs base address.
 */
struct fsmc_nand_data {
	u32			pid;
	struct nand_chip	nand;
	struct mtd_partition	*partitions;
	unsigned int		nr_partitions;

	unsigned int		bank;
	struct device		*dev;
	enum access_mode	mode;
	struct clk		*clk;

	/* DMA related objects */
	struct dma_chan		*read_dma_chan;
	struct dma_chan		*write_dma_chan;
	struct completion	dma_access_complete;

	struct fsmc_nand_timings *dev_timings;

	dma_addr_t		data_pa;
	void __iomem		*data_va;
	void __iomem		*cmd_va;
	void __iomem		*addr_va;
	void __iomem		*regs_va;

	void			(*select_chip)(uint32_t bank, uint32_t busw);
};

static inline struct fsmc_nand_data *mtd_to_fsmc(struct mtd_info *mtd)
{
	return container_of(mtd_to_nand(mtd), struct fsmc_nand_data, nand);
}

/* Assert CS signal based on chipnr */
static void fsmc_select_chip(struct mtd_info *mtd, int chipnr)