[PATCH 5/5] drivers: mtd: add Samsung SoC OneNAND driver

Ben Dooks ben-linux at fluff.org
Tue Apr 27 01:19:17 EDT 2010


On Fri, Apr 09, 2010 at 08:57:46AM +0200, Marek Szyprowski wrote:
> From: Kyungmin Park <kyungmin.park at samsung.com>
> 
> This patch adds a driver for OneNAND controller on Samsung SoCs.
> Following SoCs are supported: S3C6400, S3C6410, S5PC100 and S5PC110.
> 
> Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
> Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
> ---
>  drivers/mtd/onenand/Kconfig   |    7 +
>  drivers/mtd/onenand/Makefile  |    1 +
>  drivers/mtd/onenand/samsung.c | 1019 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 1027 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/mtd/onenand/samsung.c
> 
> diff --git a/drivers/mtd/onenand/Kconfig b/drivers/mtd/onenand/Kconfig
> index 3a9f157..9a49d68 100644
> --- a/drivers/mtd/onenand/Kconfig
> +++ b/drivers/mtd/onenand/Kconfig
> @@ -30,6 +30,13 @@ config MTD_ONENAND_OMAP2
>  	  Support for a OneNAND flash device connected to an OMAP2/OMAP3 CPU
>  	  via the GPMC memory controller.
>  
> +config MTD_ONENAND_SAMSUNG
> +        tristate "OneNAND on Samsung SOC controller support"
> +        depends on MTD_ONENAND && (ARCH_S3C64XX || ARCH_S5PC100 || ARCH_S5PV210)
> +        help
> +          Support for a OneNAND flash device connected to an Samsung SOC
> +          S3C64XX/S5PC1XX controller.
> +
>  config MTD_ONENAND_OTP
>  	bool "OneNAND OTP Support"
>  	select HAVE_MTD_OTP
> diff --git a/drivers/mtd/onenand/Makefile b/drivers/mtd/onenand/Makefile
> index 64b6cc6..2b7884c 100644
> --- a/drivers/mtd/onenand/Makefile
> +++ b/drivers/mtd/onenand/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_MTD_ONENAND)		+= onenand.o
>  # Board specific.
>  obj-$(CONFIG_MTD_ONENAND_GENERIC)	+= generic.o
>  obj-$(CONFIG_MTD_ONENAND_OMAP2)		+= omap2.o
> +obj-$(CONFIG_MTD_ONENAND_SAMSUNG)       += samsung.o
>  
>  # Simulator
>  obj-$(CONFIG_MTD_ONENAND_SIM)		+= onenand_sim.o
> diff --git a/drivers/mtd/onenand/samsung.c b/drivers/mtd/onenand/samsung.c
> new file mode 100644
> index 0000000..a902f2e
> --- /dev/null
> +++ b/drivers/mtd/onenand/samsung.c
> @@ -0,0 +1,1019 @@
> +/*
> + * Samsung S3C64XX/S5PC1XX OneNAND driver
> + *
> + *  Copyright (C) 2008-2010 Samsung Electronics
> + *  Kyungmin Park <kyungmin.park at samsung.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * Implementation:
> + *	Emulate the pseudo BufferRAM
> + */
> +
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/onenand.h>
> +#include <linux/mtd/partitions.h>
> +#include <linux/dma-mapping.h>
> +
> +#include <asm/mach/flash.h>
> +#include <plat/regs-onenand.h>
> +
> +#include <linux/io.h>
> +
> +#ifdef SAMSUNG_DEBUG
> +#define DPRINTK(format, args...)					      \
> +do {									      \
> +	printk(KERN_INFO "%s[%d]: " format "\n", __func__, __LINE__, ##args); \
> +} while (0)
> +#else
> +#define DPRINTK(...)			do { } while (0)
> +#endif

could you use dev_dbg() here instrad of DPRINTK?

> +enum soc_type {
> +	TYPE_S3C6400,
> +	TYPE_S3C6410,
> +	TYPE_S5PC100,
> +	TYPE_S5PC110,
> +};
> +
> +#define S3C64XX_AHB_ADDR		0x20000000
> +#define S5PC100_AHB_ADDR		0xB0000000

could these be passed in via platform device resources?

> +#define ONENAND_ERASE_STATUS		0x00
> +#define ONENAND_MULTI_ERASE_SET		0x01
> +#define ONENAND_ERASE_START		0x03
> +#define ONENAND_UNLOCK_START		0x08
> +#define ONENAND_UNLOCK_END		0x09
> +#define ONENAND_LOCK_START		0x0A
> +#define ONENAND_LOCK_END		0x0B
> +#define ONENAND_LOCK_TIGHT_START	0x0C
> +#define ONENAND_LOCK_TIGHT_END		0x0D
> +#define ONENAND_UNLOCK_ALL		0x0E
> +#define ONENAND_OTP_ACCESS		0x12
> +#define ONENAND_SPARE_ACCESS_ONLY	0x13
> +#define ONENAND_MAIN_ACCESS_ONLY	0x14
> +#define ONENAND_ERASE_VERIFY		0x15
> +#define ONENAND_MAIN_SPARE_ACCESS	0x16
> +#define ONENAND_PIPELINE_READ		0x4000
> +
> +#if defined(CONFIG_ARCH_S3C64XX)
> +#define MAP_00				(0x0 << 24)
> +#define MAP_01				(0x1 << 24)
> +#define MAP_10				(0x2 << 24)
> +#define MAP_11				(0x3 << 24)
> +#elif defined(CONFIG_ARCH_S5PC100) || defined(CONFIG_ARCH_S5PV210)
> +#define MAP_00				(0x0 << 26)
> +#define MAP_01				(0x1 << 26)
> +#define MAP_10				(0x2 << 26)
> +#define MAP_11				(0x3 << 26)
> +#endif
> +
> +/* The 'addr' is byte address. It makes a 16-bit word */
> +#define CMD_MAP_00(addr)		(MAP_00 | ((addr) << 1))
> +#define CMD_MAP_01(mem_addr)		(MAP_01 | (mem_addr))
> +#define CMD_MAP_10(mem_addr)		(MAP_10 | (mem_addr))
> +#define CMD_MAP_11(addr)		(MAP_11 | ((addr) << 2))
> +
> +#define S3C6400_FBA_SHIFT		10
> +#define S3C6400_FPA_SHIFT		4
> +#define S3C6400_FSA_SHIFT		2
> +
> +#define S3C6410_FBA_SHIFT		12
> +#define S3C6410_FPA_SHIFT		6
> +#define S3C6410_FSA_SHIFT		4
> +
> +#define S5PC100_FBA_SHIFT		13
> +#define S5PC100_FPA_SHIFT		7
> +#define S5PC100_FSA_SHIFT		5
> +
> +/* S5PC110 specific definitions */
> +#define S5PC110_DMA_OFFSET		0x600000
> +#define S5PC110_DMA_SRC_ADDR		0x400
> +#define S5PC110_DMA_SRC_CFG		0x404
> +#define S5PC110_DMA_DST_ADDR		0x408
> +#define S5PC110_DMA_DST_CFG		0x40C
> +#define S5PC110_DMA_TRANS_SIZE		0x414
> +#define S5PC110_DMA_TRANS_CMD		0x418
> +#define S5PC110_DMA_TRANS_STATUS	0x41C
> +#define S5PC110_DMA_TRANS_DIR		0x420
> +
> +#define S5PC110_DMA_CFG_SINGLE		(0x0 << 16)
> +#define S5PC110_DMA_CFG_4BURST		(0x2 << 16)
> +#define S5PC110_DMA_CFG_8BURST		(0x3 << 16)
> +#define S5PC110_DMA_CFG_16BURST		(0x4 << 16)
> +
> +#define S5PC110_DMA_CFG_INC		(0x0 << 8)
> +#define S5PC110_DMA_CFG_CNT		(0x1 << 8)
> +
> +#define S5PC110_DMA_CFG_8BIT		(0x0 << 0)
> +#define S5PC110_DMA_CFG_16BIT		(0x1 << 0)
> +#define S5PC110_DMA_CFG_32BIT		(0x2 << 0)
> +
> +#define S5PC110_DMA_SRC_CFG_READ	(S5PC110_DMA_CFG_16BURST | \
> +					S5PC110_DMA_CFG_INC | \
> +					S5PC110_DMA_CFG_16BIT)
> +#define S5PC110_DMA_DST_CFG_READ	(S5PC110_DMA_CFG_16BURST | \
> +					S5PC110_DMA_CFG_INC | \
> +					S5PC110_DMA_CFG_32BIT)
> +#define S5PC110_DMA_SRC_CFG_WRITE	(S5PC110_DMA_CFG_16BURST | \
> +					S5PC110_DMA_CFG_INC | \
> +					S5PC110_DMA_CFG_32BIT)
> +#define S5PC110_DMA_DST_CFG_WRITE	(S5PC110_DMA_CFG_16BURST | \
> +					S5PC110_DMA_CFG_INC | \
> +					S5PC110_DMA_CFG_16BIT)
> +
> +#define S5PC110_DMA_TRANS_CMD_TDC	(0x1 << 18)
> +#define S5PC110_DMA_TRANS_CMD_TEC	(0x1 << 16)
> +#define S5PC110_DMA_TRANS_CMD_TR	(0x1 << 0)
> +
> +#define S5PC110_DMA_TRANS_STATUS_TD	(0x1 << 18)
> +#define S5PC110_DMA_TRANS_STATUS_TB	(0x1 << 17)
> +#define S5PC110_DMA_TRANS_STATUS_TE	(0x1 << 16)
> +
> +#define S5PC110_DMA_DIR_READ		0x0
> +#define S5PC110_DMA_DIR_WRITE		0x1
> +
> +
> +
> +struct s3c_onenand {
> +	struct mtd_info	*mtd;
> +	struct platform_device	*pdev;
> +	enum soc_type	type;
> +	void __iomem	*base;
> +	void __iomem	*ahb_addr;
> +	int		bootram_command;
> +	void __iomem	*page_buf;
> +	void __iomem	*oob_buf;
> +	unsigned int	(*mem_addr)(int fba, int fpa, int fsa);
> +	void __iomem	*dma_addr;
> +	unsigned long	phys_base;
> +#ifdef CONFIG_MTD_PARTITIONS
> +	struct mtd_partition *parts;
> +#endif
> +};
> +
> +static struct s3c_onenand *onenand;
> +
> +#ifdef CONFIG_MTD_PARTITIONS
> +static const char *part_probes[] = { "cmdlinepart", NULL, };
> +#endif
> +
> +static int s3c_read_reg(int offset)
> +{
> +	return readl(onenand->base + offset);
> +}
> +
> +static void s3c_write_reg(int value, int offset)
> +{
> +	writel(value, onenand->base + offset);
> +}

I can sort of see why you've done this, it would be interesting to see
if the compiler is continually reloading onenand->base or not (currently
too lazy to try this myself).

> +static int s3c_read_cmd(unsigned int cmd)
> +{
> +	return readl(onenand->ahb_addr + cmd);
> +}
> +
> +static void s3c_write_cmd(int value, unsigned int cmd)
> +{
> +	writel(value, onenand->ahb_addr + cmd);
> +}
> +
> +#ifdef SAMSUNG_DEBUG
> +static void s3c_dump_reg(void)
> +{
> +	int i;
> +
> +	for (i = 0; i < 0x400; i += 0x40) {
> +		printk(KERN_INFO "0x%08X: 0x%08x 0x%08x 0x%08x 0x%08x\n",
> +			(unsigned int) onenand->base + i,
> +			s3c_read_reg(i), s3c_read_reg(i + 0x10),
> +			s3c_read_reg(i + 0x20), s3c_read_reg(i + 0x30));
> +	}
> +}
> +#endif
> +
> +static unsigned int s3c6400_mem_addr(int fba, int fpa, int fsa)
> +{
> +	return (fba << S3C6400_FBA_SHIFT) | (fpa << S3C6400_FPA_SHIFT) |
> +		(fsa << S3C6400_FSA_SHIFT);
> +}
> +
> +static unsigned int s3c6410_mem_addr(int fba, int fpa, int fsa)
> +{
> +	return (fba << S3C6410_FBA_SHIFT) | (fpa << S3C6410_FPA_SHIFT) |
> +		(fsa << S3C6410_FSA_SHIFT);
> +}
> +
> +static unsigned int s5pc100_mem_addr(int fba, int fpa, int fsa)
> +{
> +	return (fba << S5PC100_FBA_SHIFT) | (fpa << S5PC100_FPA_SHIFT) |
> +		(fsa << S5PC100_FSA_SHIFT);
> +}
> +
> +static void s3c_onenand_reset(void)
> +{
> +	unsigned long timeout = 0x10000;
> +	int stat;
> +
> +	s3c_write_reg(ONENAND_MEM_RESET_COLD, MEM_RESET_OFFSET);
> +	while (1 && timeout--) {
> +		stat = s3c_read_reg(INT_ERR_STAT_OFFSET);
> +		if (stat & RST_CMP)
> +			break;
> +	}
> +	stat = s3c_read_reg(INT_ERR_STAT_OFFSET);
> +	s3c_write_reg(stat, INT_ERR_ACK_OFFSET);
> +
> +	/* Clear interrupt */
> +	s3c_write_reg(0x0, INT_ERR_ACK_OFFSET);
> +	/* Clear the ECC status */
> +	s3c_write_reg(0x0, ECC_ERR_STAT_OFFSET);
> +}
> +
> +static unsigned short s3c_onenand_readw(void __iomem *addr)
> +{
> +	struct onenand_chip *this = onenand->mtd->priv;
> +	int reg = addr - this->base;
> +	int word_addr = reg >> 1;
> +	int value;
> +
> +	/* It's used for probing time */
> +	switch (reg) {
> +	case ONENAND_REG_MANUFACTURER_ID:
> +		return s3c_read_reg(MANUFACT_ID_OFFSET);
> +	case ONENAND_REG_DEVICE_ID:
> +		return s3c_read_reg(DEVICE_ID_OFFSET);
> +	case ONENAND_REG_VERSION_ID:
> +		return s3c_read_reg(FLASH_VER_ID_OFFSET);
> +	case ONENAND_REG_DATA_BUFFER_SIZE:
> +		return s3c_read_reg(DATA_BUF_SIZE_OFFSET);
> +	case ONENAND_REG_TECHNOLOGY:
> +		return s3c_read_reg(TECH_OFFSET);
> +	case ONENAND_REG_SYS_CFG1:
> +		return s3c_read_reg(MEM_CFG_OFFSET);
> +
> +	/* Used at unlock all status */
> +	case ONENAND_REG_CTRL_STATUS:
> +		return 0;
> +
> +	case ONENAND_REG_WP_STATUS:
> +		return ONENAND_WP_US;
> +
> +	default:
> +		break;
> +	}
> +
> +	/* BootRAM access control */
> +	if ((unsigned int) addr < ONENAND_DATARAM && onenand->bootram_command) {
> +		if (word_addr == 0)
> +			return s3c_read_reg(MANUFACT_ID_OFFSET);
> +		if (word_addr == 1)
> +			return s3c_read_reg(DEVICE_ID_OFFSET);
> +		if (word_addr == 2)
> +			return s3c_read_reg(FLASH_VER_ID_OFFSET);
> +	}
> +
> +	value = s3c_read_cmd(CMD_MAP_11(word_addr)) & 0xffff;
> +	dev_info(&onenand->mtd->dev, "s3c_onenand_readw:  Illegal access"
> +		" at reg 0x%x, value 0x%x\n", word_addr, value);
> +	return value;
> +}
> +
> +static void s3c_onenand_writew(unsigned short value, void __iomem *addr)
> +{
> +	struct onenand_chip *this = onenand->mtd->priv;
> +	int reg = addr - this->base;
> +	int word_addr = reg >> 1;

is addr likely to ever be below base? if not, then could this be changed
to an 'unsigned int' reg and avoid the typecasting below? or is this due
to a compiler or sparse warning?

> +	/* It's used for probing time */
> +	switch (reg) {
> +	case ONENAND_REG_SYS_CFG1:
> +		s3c_write_reg(value, MEM_CFG_OFFSET);
> +		return;
> +
> +	case ONENAND_REG_START_ADDRESS1:
> +	case ONENAND_REG_START_ADDRESS2:
> +		return;
> +
> +	/* Lock/lock-tight/unlock/unlock_all */
> +	case ONENAND_REG_START_BLOCK_ADDRESS:
> +		return;
> +
> +	default:
> +		break;
> +	}
> +
> +	/* BootRAM access control */
> +	if ((unsigned int) addr < ONENAND_DATARAM) {
> +		if (value == ONENAND_CMD_READID) {
> +			onenand->bootram_command = 1;
> +			return;
> +		}
> +		if (value == ONENAND_CMD_RESET) {
> +			s3c_write_reg(ONENAND_MEM_RESET_COLD, MEM_RESET_OFFSET);
> +			onenand->bootram_command = 0;
> +			return;
> +		}
> +	}
> +
> +	dev_info(&onenand->mtd->dev, "s3c_onenand_writew: Illegal access"
> +		" at reg 0x%x, value 0x%x\n", word_addr, value);
> +
> +	s3c_write_cmd(value, CMD_MAP_11(word_addr));
> +}
> +
> +static int s3c_onenand_wait(struct mtd_info *mtd, int state)
> +{
> +	unsigned int flags = INT_ACT;
> +	unsigned int stat, ecc;
> +	unsigned long timeout;
> +
> +	switch (state) {
> +	case FL_READING:
> +		flags |= BLK_RW_CMP | LOAD_CMP;
> +		break;
> +	case FL_WRITING:
> +		flags |= BLK_RW_CMP | PGM_CMP;
> +		break;
> +	case FL_ERASING:
> +		flags |= BLK_RW_CMP | ERS_CMP;
> +		break;
> +	case FL_LOCKING:
> +		flags |= BLK_RW_CMP;
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	/* The 20 msec is enough */
> +	timeout = jiffies + msecs_to_jiffies(20);
> +	while (time_before(jiffies, timeout)) {
> +		stat = s3c_read_reg(INT_ERR_STAT_OFFSET);
> +		if (stat & flags)
> +			break;
> +
> +		if (state != FL_READING)
> +			cond_resched();
> +	}
> +	/* To get correct interrupt status in timeout case */
> +	stat = s3c_read_reg(INT_ERR_STAT_OFFSET);
> +	s3c_write_reg(stat, INT_ERR_ACK_OFFSET);
> +
> +	/*
> +	 * In the Spec. it checks the controller status first
> +	 * However if you get the correct information in case of
> +	 * power off recovery (POR) test, it should read ECC status first
> +	 */
> +	if (stat & LOAD_CMP) {
> +		ecc = s3c_read_reg(ECC_ERR_STAT_OFFSET);
> +		if (ecc & ONENAND_ECC_4BIT_UNCORRECTABLE) {
> +			dev_info(&mtd->dev, "onenand_wait: ECC error"
> +				 " = 0x%04x\n", ecc);

This is a valid place for not wrapping the format string.

I think you may also want to use %s: and make the first va-arg __func__
see also all next usage of dev_. 

> +			mtd->ecc_stats.failed++;
> +			return -EBADMSG;
> +		}
> +	}
> +
> +	if (stat & (LOCKED_BLK | ERS_FAIL | PGM_FAIL | LD_FAIL_ECC_ERR)) {
> +		dev_info(&mtd->dev, "onenand_wait: controller error = 0x%04x\n",
> +			 stat);
> +		if (stat & LOCKED_BLK)
> +			dev_info(&mtd->dev, "onenand_wait: it's locked error"
> +				 " = 0x%04x\n", stat);
> +
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
> +static int s3c_onenand_command(struct mtd_info *mtd, int cmd, loff_t addr,
> +			       size_t len)
> +{
> +	struct onenand_chip *this = mtd->priv;
> +	unsigned int *m, *s;
> +	int fba, fpa, fsa = 0;
> +	unsigned int mem_addr;
> +	int i, mcount, scount;
> +	int index;
> +
> +	fba = (int) (addr >> this->erase_shift);
> +	fpa = (int) (addr >> this->page_shift);
> +	fpa &= this->page_mask;
> +
> +	mem_addr = onenand->mem_addr(fba, fpa, fsa);
> +
> +	switch (cmd) {
> +	case ONENAND_CMD_READ:
> +	case ONENAND_CMD_READOOB:
> +	case ONENAND_CMD_BUFFERRAM:
> +		ONENAND_SET_NEXT_BUFFERRAM(this);
> +	default:
> +		break;
> +	}
> +
> +	index = ONENAND_CURRENT_BUFFERRAM(this);
> +
> +	/*
> +	 * Emulate Two BufferRAMs and access with 4 bytes pointer
> +	 */
> +	m = (unsigned int *) onenand->page_buf;
> +	s = (unsigned int *) onenand->oob_buf;
> +
> +	if (index) {
> +		m += (this->writesize >> 2);
> +		s += (mtd->oobsize >> 2);
> +	}
> +
> +	mcount = mtd->writesize >> 2;
> +	scount = mtd->oobsize >> 2;
> +
> +	switch (cmd) {
> +	case ONENAND_CMD_READ:
> +		/* Main */
> +		for (i = 0; i < mcount; i++)
> +			*m++ = s3c_read_cmd(CMD_MAP_01(mem_addr));
> +		return 0;
> +
> +	case ONENAND_CMD_READOOB:
> +		s3c_write_reg(TSRF, TRANS_SPARE_OFFSET);
> +		/* Main */
> +		for (i = 0; i < mcount; i++)
> +			*m++ = s3c_read_cmd(CMD_MAP_01(mem_addr));
> +
> +		/* Spare */
> +		for (i = 0; i < scount; i++)
> +			*s++ = s3c_read_cmd(CMD_MAP_01(mem_addr));
> +
> +		s3c_write_reg(0, TRANS_SPARE_OFFSET);
> +		return 0;
> +
> +	case ONENAND_CMD_PROG:
> +		/* Main */
> +		for (i = 0; i < mcount; i++)
> +			s3c_write_cmd(*m++, CMD_MAP_01(mem_addr));
> +		return 0;
> +
> +	case ONENAND_CMD_PROGOOB:
> +		s3c_write_reg(TSRF, TRANS_SPARE_OFFSET);
> +
> +		/* Main - dummy write */
> +		for (i = 0; i < mcount; i++)
> +			s3c_write_cmd(0xffffffff, CMD_MAP_01(mem_addr));
> +
> +		/* Spare */
> +		for (i = 0; i < scount; i++)
> +			s3c_write_cmd(*s++, CMD_MAP_01(mem_addr));
> +
> +		s3c_write_reg(0, TRANS_SPARE_OFFSET);
> +		return 0;
> +
> +	case ONENAND_CMD_UNLOCK_ALL:
> +		s3c_write_cmd(ONENAND_UNLOCK_ALL, CMD_MAP_10(mem_addr));
> +		return 0;
> +
> +	case ONENAND_CMD_ERASE:
> +		s3c_write_cmd(ONENAND_ERASE_START, CMD_MAP_10(mem_addr));
> +		return 0;
> +
> +	default:
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static unsigned char *s3c_get_bufferram(struct mtd_info *mtd, int area)
> +{
> +	struct onenand_chip *this = mtd->priv;
> +	int index = ONENAND_CURRENT_BUFFERRAM(this);
> +	unsigned char *p;
> +
> +	if (area == ONENAND_DATARAM) {
> +		p = (unsigned char *) onenand->page_buf;
> +		if (index == 1)
> +			p += this->writesize;
> +	} else {
> +		p = (unsigned char *) onenand->oob_buf;
> +		if (index == 1)
> +			p += mtd->oobsize;
> +	}
> +
> +	return p;
> +}
> +
> +static int onenand_read_bufferram(struct mtd_info *mtd, int area,
> +				  unsigned char *buffer, int offset,
> +				  size_t count)
> +{
> +	unsigned char *p;
> +
> +	p = s3c_get_bufferram(mtd, area);
> +	memcpy(buffer, p + offset, count);
> +	return 0;
> +}
> +
> +static int onenand_write_bufferram(struct mtd_info *mtd, int area,
> +				   const unsigned char *buffer, int offset,
> +				   size_t count)
> +{
> +	unsigned char *p;
> +
> +	p = s3c_get_bufferram(mtd, area);
> +	memcpy(p + offset, buffer, count);
> +	return 0;
> +}
> +
> +static int s5pc110_dma_ops(void *dst, void *src, size_t count, int direction)
> +{
> +	void __iomem *base = onenand->dma_addr;
> +	int status;
> +
> +	writel(src, base + S5PC110_DMA_SRC_ADDR);
> +	writel(dst, base + S5PC110_DMA_DST_ADDR);
> +
> +	if (direction == S5PC110_DMA_DIR_READ) {
> +		writel(S5PC110_DMA_SRC_CFG_READ, base + S5PC110_DMA_SRC_CFG);
> +		writel(S5PC110_DMA_DST_CFG_READ, base + S5PC110_DMA_DST_CFG);
> +	} else {
> +		writel(S5PC110_DMA_SRC_CFG_WRITE, base + S5PC110_DMA_SRC_CFG);
> +		writel(S5PC110_DMA_DST_CFG_WRITE, base + S5PC110_DMA_DST_CFG);
> +	}
> +
> +	writel(count, base + S5PC110_DMA_TRANS_SIZE);
> +	writel(direction, base + S5PC110_DMA_TRANS_DIR);
> +
> +	writel(S5PC110_DMA_TRANS_CMD_TR, base + S5PC110_DMA_TRANS_CMD);
> +
> +	do {
> +		status = readl(base + S5PC110_DMA_TRANS_STATUS);
> +	} while (!(status & S5PC110_DMA_TRANS_STATUS_TD));
> +
> +	if (status & S5PC110_DMA_TRANS_STATUS_TE) {
> +		writel(S5PC110_DMA_TRANS_CMD_TEC, base + S5PC110_DMA_TRANS_CMD);
> +		writel(S5PC110_DMA_TRANS_CMD_TDC, base + S5PC110_DMA_TRANS_CMD);
> +		return -EIO;
> +	}
> +
> +	writel(S5PC110_DMA_TRANS_CMD_TDC, base + S5PC110_DMA_TRANS_CMD);
> +
> +	return 0;
> +}
> +
> +static int s5pc110_read_bufferram(struct mtd_info *mtd, int area,
> +		unsigned char *buffer, int offset, size_t count)
> +{
> +	struct onenand_chip *this = mtd->priv;
> +	void __iomem *bufferram;
> +	void __iomem *p;
> +	void *buf = (void *) buffer;
> +	dma_addr_t dma_src, dma_dst;
> +	int err;
> +
> +	p = bufferram = this->base + area;
> +	if (ONENAND_CURRENT_BUFFERRAM(this)) {
> +		if (area == ONENAND_DATARAM)
> +			p += this->writesize;
> +		else
> +			p += mtd->oobsize;
> +	}
> +
> +	if (offset & 3 || (size_t) buf & 3 ||
> +		!onenand->dma_addr || count != mtd->writesize)
> +		goto normal;
> +
> +	/* Handle vmalloc address */
> +	if (buf >= high_memory) {
> +		struct page *page;
> +
> +		if (((size_t) buf & PAGE_MASK) !=
> +		    ((size_t) (buf + count - 1) & PAGE_MASK))
> +			goto normal;
> +		page = vmalloc_to_page(buf);
> +		if (!page)
> +			goto normal;
> +		buf = page_address(page) + ((size_t) buf & ~PAGE_MASK);
> +	}
> +
> +	/* DMA routine */
> +	dma_src = onenand->phys_base + (p - this->base);
> +	dma_dst = dma_map_single(&onenand->pdev->dev,
> +			buf, count, DMA_FROM_DEVICE);
> +	if (dma_mapping_error(&onenand->pdev->dev, dma_dst)) {
> +		dev_err(&onenand->pdev->dev,
> +			"Couldn't DMA map a %d byte buffer\n", count);
> +		goto normal;
> +	}
> +	err = s5pc110_dma_ops((void *) dma_dst, (void *) dma_src,
> +			count, S5PC110_DMA_DIR_READ);
> +	dma_unmap_single(&onenand->pdev->dev, dma_dst, count, DMA_FROM_DEVICE);
> +
> +	if (!err)
> +		return 0;
> +
> +normal:
> +	if (count != mtd->writesize) {
> +		/* Copy the bufferram to memory to prevent unaligned access */
> +		memcpy(this->page_buf, bufferram, mtd->writesize);
> +		p = this->page_buf + offset;
> +	}
> +
> +	memcpy(buffer, p, count);
> +
> +	return 0;
> +}
> +
> +static int s3c_onenand_bbt_wait(struct mtd_info *mtd, int state)
> +{
> +	unsigned int flags = INT_ACT | LOAD_CMP;
> +	unsigned int stat;
> +	unsigned long timeout;
> +
> +	/* The 20 msec is enough */
> +	timeout = jiffies + msecs_to_jiffies(20);
> +	while (time_before(jiffies, timeout)) {
> +		stat = s3c_read_reg(INT_ERR_STAT_OFFSET);
> +		if (stat & flags)
> +			break;
> +	}
> +	/* To get correct interrupt status in timeout case */
> +	stat = s3c_read_reg(INT_ERR_STAT_OFFSET);
> +	s3c_write_reg(stat, INT_ERR_ACK_OFFSET);
> +
> +	if (stat & LD_FAIL_ECC_ERR) {
> +		s3c_onenand_reset();
> +		return ONENAND_BBT_READ_ERROR;
> +	}
> +
> +	if (stat & LOAD_CMP) {
> +		int ecc = s3c_read_reg(ECC_ERR_STAT_OFFSET);
> +		if (ecc & ONENAND_ECC_4BIT_UNCORRECTABLE) {
> +			s3c_onenand_reset();
> +			return ONENAND_BBT_READ_ERROR;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static void s3c_onenand_check_lock_status(struct mtd_info *mtd)
> +{
> +	struct onenand_chip *this = mtd->priv;
> +	unsigned int block, end;
> +	int tmp;
> +
> +	end = this->chipsize >> this->erase_shift;
> +
> +	for (block = 0; block < end; block++) {
> +		tmp = s3c_read_cmd(CMD_MAP_01(onenand->mem_addr(block, 0, 0)));
> +
> +		if (s3c_read_reg(INT_ERR_STAT_OFFSET) & LOCKED_BLK) {
> +			dev_err(&mtd->dev, "block %d is write-protected!\n",
> +				block);
> +			s3c_write_reg(LOCKED_BLK, INT_ERR_ACK_OFFSET);
> +		}
> +	}
> +}
> +
> +static void s3c_onenand_do_lock_cmd(struct mtd_info *mtd, loff_t ofs,
> +				    size_t len, int cmd)
> +{
> +	struct onenand_chip *this = mtd->priv;
> +	int start, end, start_mem_addr, end_mem_addr;
> +
> +	start = ofs >> this->erase_shift;
> +	start_mem_addr = onenand->mem_addr(start, 0, 0);
> +	end = start + (len >> this->erase_shift) - 1;
> +	end_mem_addr = onenand->mem_addr(end, 0, 0);
> +
> +	if (cmd == ONENAND_CMD_LOCK) {
> +		s3c_write_cmd(ONENAND_LOCK_START, CMD_MAP_10(start_mem_addr));
> +		s3c_write_cmd(ONENAND_LOCK_END, CMD_MAP_10(end_mem_addr));
> +	} else {
> +		s3c_write_cmd(ONENAND_UNLOCK_START, CMD_MAP_10(start_mem_addr));
> +		s3c_write_cmd(ONENAND_UNLOCK_END, CMD_MAP_10(end_mem_addr));
> +	}
> +
> +	this->wait(mtd, FL_LOCKING);
> +}
> +
> +static void s3c_unlock_all(struct mtd_info *mtd)
> +{
> +	struct onenand_chip *this = mtd->priv;
> +	loff_t ofs = 0;
> +	size_t len = this->chipsize;
> +
> +	if (this->options & ONENAND_HAS_UNLOCK_ALL) {
> +		/* Write unlock command */
> +		this->command(mtd, ONENAND_CMD_UNLOCK_ALL, 0, 0);
> +
> +		/* No need to check return value */
> +		this->wait(mtd, FL_LOCKING);
> +
> +		/* Workaround for all block unlock in DDP */
> +		if (!ONENAND_IS_DDP(this)) {
> +			s3c_onenand_check_lock_status(mtd);
> +			return;
> +		}
> +
> +		/* All blocks on another chip */
> +		ofs = this->chipsize >> 1;
> +		len = this->chipsize >> 1;
> +	}
> +
> +	s3c_onenand_do_lock_cmd(mtd, ofs, len, ONENAND_CMD_UNLOCK);
> +
> +	s3c_onenand_check_lock_status(mtd);
> +}
> +
> +static void s3c_onenand_setup(struct mtd_info *mtd)
> +{
> +	struct onenand_chip *this = mtd->priv;
> +
> +	onenand->mtd = mtd;
> +
> +	if (onenand->type == TYPE_S3C6400)
> +		onenand->mem_addr = s3c6400_mem_addr;
> +	if (onenand->type == TYPE_S3C6410)
> +		onenand->mem_addr = s3c6410_mem_addr;
> +	if (onenand->type == TYPE_S5PC100)
> +		onenand->mem_addr = s5pc100_mem_addr;
> +	if (onenand->type == TYPE_S5PC110) {
> +		/* Use generic onenand functions */
> +		this->read_bufferram = s5pc110_read_bufferram;
> +		return;
> +	}
> +
> +	this->read_word = s3c_onenand_readw;
> +	this->write_word = s3c_onenand_writew;
> +
> +	this->wait = s3c_onenand_wait;
> +	this->bbt_wait = s3c_onenand_bbt_wait;
> +	this->unlock_all = s3c_unlock_all;
> +	this->command = s3c_onenand_command;
> +
> +	this->read_bufferram = onenand_read_bufferram;
> +	this->write_bufferram = onenand_write_bufferram;
> +}
> +
> +static int s3c_onenand_probe(struct platform_device *pdev)
> +{
> +	struct onenand_platform_data *pdata;
> +	struct onenand_chip *this;
> +	struct mtd_info *mtd;
> +	struct resource *r;
> +	int size, err;
> +	unsigned long ahb_addr = 0, ahb_addr_size;
> +	unsigned long onenand_ctrl_cfg = 0;
> +
> +	pdata = pdev->dev.platform_data;
> +	/* No need to check pdata. the platform data is optional */
> +
> +	size = sizeof(struct mtd_info) + sizeof(struct onenand_chip);
> +	mtd = kzalloc(size, GFP_KERNEL);
> +	if (!mtd) {
> +		dev_err(&pdev->dev, "failed to allocate memory\n");
> +		return -ENOMEM;
> +	}
> +
> +	onenand = kzalloc(sizeof(struct s3c_onenand), GFP_KERNEL);
> +	if (!onenand) {
> +		err = -ENOMEM;
> +		goto onenand_fail;
> +	}
> +
> +	this = (struct onenand_chip *) &mtd[1];
> +	mtd->priv = this;
> +	mtd->dev.parent = &pdev->dev;
> +	mtd->owner = THIS_MODULE;
> +	onenand->pdev = pdev;
> +	onenand->type = platform_get_device_id(pdev)->driver_data;
> +
> +	s3c_onenand_setup(mtd);
> +
> +	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!r) {
> +		dev_err(&pdev->dev, "no resource defined\n");
> +		return -ENXIO;

If i rember correctly, -ENXIO will make the driver layer fail to report
any binding issue. However there seems to be a group of people who feel
that using filesystem errors such as -ENOENT inappropriate for drivers...

Not sure what to recommend here, maybe just leave as is.

> +		goto resource_failed;
> +	}
> +
> +	r = request_mem_region(r->start, resource_size(r), pdev->name);
> +	if (!r) {
> +		dev_err(&pdev->dev, "failed to request memory resource\n");
> +		err = -EBUSY;
> +		goto request_failed;
> +	}
> +
> +	onenand->base = ioremap(r->start, resource_size(r));
> +	if (!onenand->base) {

would be nice to have an error print here, but not essential.

> +		err = -EFAULT;
> +		goto ioremap_failed;
> +	}
> +	/* Set onenand_chip also */
> +	this->base = onenand->base;
> +
> +	if (onenand->type == TYPE_S3C6400 || onenand->type == TYPE_S3C6410) {
> +		ahb_addr = S3C64XX_AHB_ADDR;
> +		ahb_addr_size = SZ_64M;
> +	} else if (onenand->type == TYPE_S5PC100) {
> +		ahb_addr = S5PC100_AHB_ADDR;
> +		ahb_addr_size = SZ_256M - SZ_32M;
> +	} else if (onenand->type == TYPE_S5PC110) {
> +		onenand->dma_addr =
> +			ioremap(r->start + S5PC110_DMA_OFFSET, 0x800);
> +		if (!onenand->dma_addr)
> +			onenand->dma_addr = 0;
> +		onenand->phys_base = S5PC110_ONENAND_BASE;
> +	}

would be nice to have a

      else {
      	   BUG();
      }

to catch unhandled types.


> +
> +	/*
> +	 * We only used as followings
> +	 * S5PC100                              S3C64XX
> +	 * MAP_01 0xB4000000 ~ 0xB4FFFFFF       0x21000000 ~ 0x21FFFFFF
> +	 * MAP_10 0xB8000000 ~ 0xB8FFFFFF       0x22000000 ~ 0x22FFFFFF
> +	 * MAP_11 0xBC000000 ~ 0xBCFFFFFF       0x23000000 ~ 0x23FFFFFF
> +	 */
> +	if (ahb_addr) {
> +		/* We don't use last 32MiB */
> +		onenand->ahb_addr = ioremap(ahb_addr, ahb_addr_size);
> +		if (!onenand->ahb_addr) {
> +			err = -EINVAL;
> +			goto ahb_failed;
> +		}

I think I mentioned above that it would be nice to have these passed in as
platform resources. Please look into this or provide a note in the driver
as to why you can't do this.

> +		/* Allocate 4KiB BufferRAM */
> +		onenand->page_buf = kzalloc(SZ_4K * sizeof(char), GFP_KERNEL);
> +		if (!onenand->page_buf) {
> +			err = -ENOMEM;
> +			goto page_buf_fail;
> +		}

don't really think you need sizeof(char) here.

> +		/* Allocate 128 SpareRAM */
> +		onenand->oob_buf = kzalloc(128 * sizeof(char), GFP_KERNEL);
> +		if (!onenand->oob_buf) {
> +			err = -ENOMEM;
> +			goto oob_buf_fail;
> +		}
> +	}
> +
> +	/* Use runtime badblock check */
> +	this->options |= ONENAND_SKIP_UNLOCK_CHECK;
> +
> +	if (onenand->type == TYPE_S5PC110) {
> +		onenand_ctrl_cfg = readl(onenand->dma_addr + 0x100);
> +		if ((onenand_ctrl_cfg & ONENAND_SYS_CFG1_SYNC_WRITE) &&
> +		    onenand->dma_addr)
> +			writel(onenand_ctrl_cfg & ~ONENAND_SYS_CFG1_SYNC_WRITE,
> +					onenand->dma_addr + 0x100);
> +		else
> +			onenand_ctrl_cfg = 0;
> +	}
> +
> +	if (onenand_scan(mtd, 1)) {
> +		err = -EFAULT;
> +		goto scan_failed;
> +	}
> +
> +	if (onenand->type == TYPE_S5PC110) {
> +		if (onenand_ctrl_cfg && onenand->dma_addr)
> +			writel(onenand_ctrl_cfg, onenand->dma_addr + 0x100);
> +	}
> +
> +	if (ahb_addr) {
> +		/* S3C don't handle subpage write */
  		       does not, or doesn't

> +		mtd->subpage_sft = 0;
> +		this->subpagesize = mtd->writesize;
> +	}
> +
> +	if (s3c_read_reg(MEM_CFG_OFFSET) & ONENAND_SYS_CFG1_SYNC_READ)
> +		dev_info(&mtd->dev, "OneNAND Sync. Burst Read enabled\n");
> +
> +#ifdef CONFIG_MTD_PARTITIONS
> +	err = parse_mtd_partitions(mtd, part_probes, &onenand->parts, 0);
> +	if (err > 0)
> +		add_mtd_partitions(mtd, onenand->parts, err);
> +	else if (err <= 0 && pdata && pdata->parts)
> +		add_mtd_partitions(mtd, pdata->parts, pdata->nr_parts);
> +	else
> +#endif
> +		err = add_mtd_device(mtd);
> +
> +	platform_set_drvdata(pdev, mtd);
> +
> +	return 0;
> +scan_failed:
> +	kfree(onenand->oob_buf);
> +oob_buf_fail:
> +	kfree(onenand->page_buf);
> +page_buf_fail:
> +	if (onenand->ahb_addr)
> +		iounmap(onenand->ahb_addr);
> +ahb_failed:
> +	if (onenand->dma_addr)
> +		iounmap(onenand->dma_addr);
> +	iounmap(onenand->base);
> +ioremap_failed:
> +	release_mem_region(r->start, resource_size(r));
> +request_failed:
> +resource_failed:
> +	kfree(onenand);
> +onenand_fail:
> +	kfree(mtd);
> +	return err;
> +}
> +
> +static int __devexit s3c_onenand_remove(struct platform_device *pdev)
> +{
> +	struct mtd_info *mtd = platform_get_drvdata(pdev);
> +
> +	onenand_release(mtd);
> +	if (onenand->ahb_addr)
> +		iounmap(onenand->ahb_addr);
> +	if (onenand->dma_addr)
> +		iounmap(onenand->dma_addr);
> +	iounmap(onenand->base);
> +	platform_set_drvdata(pdev, NULL);
> +	kfree(onenand->oob_buf);
> +	kfree(onenand->page_buf);
> +	kfree(onenand);
> +	kfree(mtd);
> +	return 0;
> +}
> +
> +static int s3c_pm_ops_suspend(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct mtd_info *mtd = platform_get_drvdata(pdev);
> +	struct onenand_chip *this = mtd->priv;
> +
> +	this->wait(mtd, FL_PM_SUSPENDED);
> +	return mtd->suspend(mtd);
> +}
> +
> +static  int s3c_pm_ops_resume(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct mtd_info *mtd = platform_get_drvdata(pdev);
> +	struct onenand_chip *this = mtd->priv;
> +
> +	mtd->resume(mtd);
> +	this->unlock_all(mtd);
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops s3c_pm_ops = {
> +	.suspend	= s3c_pm_ops_suspend,
> +	.resume		= s3c_pm_ops_resume,
> +};
> +
> +static struct platform_device_id s3c_onenand_driver_ids[] = {
> +	{
> +		.name		= "s3c6400-onenand",
> +		.driver_data	= TYPE_S3C6400,
> +	}, {
> +		.name		= "s3c6410-onenand",
> +		.driver_data	= TYPE_S3C6410,
> +	}, {
> +		.name		= "s5pc100-onenand",
> +		.driver_data	= TYPE_S5PC100,
> +	}, {
> +		.name		= "s5pc110-onenand",
> +		.driver_data	= TYPE_S5PC110,
> +	}, { },
> +};
> +MODULE_DEVICE_TABLE(platform, s3c_onenand_driver_ids);
> +
> +static struct platform_driver s3c_onenand_driver = {
> +	.id_table	= s3c_onenand_driver_ids,
> +	.driver         = {
> +		.name	= "samsung-onenand",
> +		.pm	= &s3c_pm_ops,
> +	},
> +	.probe          = s3c_onenand_probe,
> +	.remove         = __devexit_p(s3c_onenand_remove),
> +};

would look nicer if .id_table after .driver, and also be in alphabetical
order too.

> +static int __init s3c_onenand_init(void)
> +{
> +	return platform_driver_register(&s3c_onenand_driver);
> +}
> +
> +static void __exit s3c_onenand_exit(void)
> +{
> +	platform_driver_unregister(&s3c_onenand_driver);
> +}
> +
> +module_init(s3c_onenand_init);
> +module_exit(s3c_onenand_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Kyungmin Park <kyungmin.park at samsung.com>");
> +MODULE_DESCRIPTION("Samsung OneNAND controller support");
> +MODULE_ALIAS("platform:samsung-onenand");

don't think you need a MODULE_ALIAS when you have a MODULE_DEVICE_TABLE
decleration, the module tools should support reading this table for use
with the autoloader.

Don't see any show stopping problems with this. It would be nice to
sort out as many of the issues raised before final submission.

-- 
Ben

Q:      What's a light-year?
A:      One-third less calories than a regular year.




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