drivers/mtd/spi/atmel.c - platform/external/u-boot - Gitiles

 /*
  * Atmel SPI DataFlash support
  *
  * Copyright (C) 2008 Atmel Corporation
  * Licensed under the GPL-2 or later.
  */

 #include <common.h>
 #include <malloc.h>
 #include <spi_flash.h>

 #include "spi_flash_internal.h"

 /* AT45-specific commands */
 #define CMD_AT45_READ_STATUS		0xd7
 #define CMD_AT45_ERASE_PAGE		0x81
 #define CMD_AT45_LOAD_PROG_BUF1		0x82
 #define CMD_AT45_LOAD_BUF1		0x84
 #define CMD_AT45_LOAD_PROG_BUF2		0x85
 #define CMD_AT45_LOAD_BUF2		0x87
 #define CMD_AT45_PROG_BUF1		0x88
 #define CMD_AT45_PROG_BUF2		0x89

 /* AT45 status register bits */
 #define AT45_STATUS_P2_PAGE_SIZE	(1 << 0)
 #define AT45_STATUS_READY		(1 << 7)

 /* DataFlash family IDs, as obtained from the second idcode byte */
 #define DF_FAMILY_AT26F			0
 #define DF_FAMILY_AT45			1
 #define DF_FAMILY_AT26DF		2	/* AT25DF and AT26DF */

 struct atmel_spi_flash_params {
 	u8		idcode1;
 	/* Log2 of page size in power-of-two mode */
 	u8		l2_page_size;
 	u8		pages_per_block;
 	u8		blocks_per_sector;
 	u8		nr_sectors;
 	const char	*name;
 };

 /* spi_flash needs to be first so upper layers can free() it */
 struct atmel_spi_flash {
 	struct spi_flash flash;
 	const struct atmel_spi_flash_params *params;
 };

 static inline struct atmel_spi_flash *
 to_atmel_spi_flash(struct spi_flash *flash)
 {
 	return container_of(flash, struct atmel_spi_flash, flash);
 }

 static const struct atmel_spi_flash_params atmel_spi_flash_table[] = {
 	{
 		.idcode1		= 0x22,
 		.l2_page_size		= 8,
 		.pages_per_block	= 8,
 		.blocks_per_sector	= 16,
 		.nr_sectors		= 4,
 		.name			= "AT45DB011D",
 	},
 	{
 		.idcode1		= 0x23,
 		.l2_page_size		= 8,
 		.pages_per_block	= 8,
 		.blocks_per_sector	= 16,
 		.nr_sectors		= 8,
 		.name			= "AT45DB021D",
 	},
 	{
 		.idcode1		= 0x24,
 		.l2_page_size		= 8,
 		.pages_per_block	= 8,
 		.blocks_per_sector	= 32,
 		.nr_sectors		= 8,
 		.name			= "AT45DB041D",
 	},
 	{
 		.idcode1		= 0x25,
 		.l2_page_size		= 8,
 		.pages_per_block	= 8,
 		.blocks_per_sector	= 32,
 		.nr_sectors		= 16,
 		.name			= "AT45DB081D",
 	},
 	{
 		.idcode1		= 0x26,
 		.l2_page_size		= 9,
 		.pages_per_block	= 8,
 		.blocks_per_sector	= 32,
 		.nr_sectors		= 16,
 		.name			= "AT45DB161D",
 	},
 	{
 		.idcode1		= 0x27,
 		.l2_page_size		= 9,
 		.pages_per_block	= 8,
 		.blocks_per_sector	= 64,
 		.nr_sectors		= 64,
 		.name			= "AT45DB321D",
 	},
 	{
 		.idcode1		= 0x28,
 		.l2_page_size		= 10,
 		.pages_per_block	= 8,
 		.blocks_per_sector	= 32,
 		.nr_sectors		= 32,
 		.name			= "AT45DB642D",
 	},
 	{
 		.idcode1		= 0x47,
 		.l2_page_size		= 8,
 		.pages_per_block	= 16,
 		.blocks_per_sector	= 16,
 		.nr_sectors		= 64,
 		.name			= "AT25DF321",
 	},
 };

 static int at45_wait_ready(struct spi_flash *flash, unsigned long timeout)
 {
 	struct spi_slave *spi = flash->spi;
 	unsigned long timebase;
 	int ret;
 	u8 cmd = CMD_AT45_READ_STATUS;
 	u8 status;

 	timebase = get_timer(0);

 	ret = spi_xfer(spi, 8, &cmd, NULL, SPI_XFER_BEGIN);
 	if (ret)
 		return -1;

 	do {
 		ret = spi_xfer(spi, 8, NULL, &status, 0);
 		if (ret)
 			return -1;

 		if (status & AT45_STATUS_READY)
 			break;
 	} while (get_timer(timebase) < timeout);

 	/* Deactivate CS */
 	spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);

 	if (status & AT45_STATUS_READY)
 		return 0;

 	/* Timed out */
 	return -1;
 }

 /*
  * Assemble the address part of a command for AT45 devices in
  * non-power-of-two page size mode.
  */
 static void at45_build_address(struct atmel_spi_flash *asf, u8 *cmd, u32 offset)
 {
 	unsigned long page_addr;
 	unsigned long byte_addr;
 	unsigned long page_size;
 	unsigned int page_shift;

 	/*
 	 * The "extra" space per page is the power-of-two page size
 	 * divided by 32.
 	 */
 	page_shift = asf->params->l2_page_size;
 	page_size = (1 << page_shift) + (1 << (page_shift - 5));
 	page_shift++;
 	page_addr = offset / page_size;
 	byte_addr = offset % page_size;

 	cmd[0] = page_addr >> (16 - page_shift);
 	cmd[1] = page_addr << (page_shift - 8) | (byte_addr >> 8);
 	cmd[2] = byte_addr;
 }

 static int dataflash_read_fast_at45(struct spi_flash *flash,
 		u32 offset, size_t len, void *buf)
 {
 	struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
 	u8 cmd[5];

 	cmd[0] = CMD_READ_ARRAY_FAST;
 	at45_build_address(asf, cmd + 1, offset);
 	cmd[4] = 0x00;

 	return spi_flash_read_common(flash, cmd, sizeof(cmd), buf, len);
 }

 /*
  * TODO: the two write funcs (_p2/_at45) should get unified ...
  */
 static int dataflash_write_p2(struct spi_flash *flash,
 		u32 offset, size_t len, const void *buf)
 {
 	struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
 	unsigned long page_size;
 	u32 addr = offset;
 	size_t chunk_len;
 	size_t actual;
 	int ret;
 	u8 cmd[4];

 	/*
 	 * TODO: This function currently uses only page buffer #1.  We can
 	 * speed this up by using both buffers and loading one buffer while
 	 * the other is being programmed into main memory.
 	 */

 	page_size = (1 << asf->params->l2_page_size);

 	ret = spi_claim_bus(flash->spi);
 	if (ret) {
 		debug("SF: Unable to claim SPI bus\n");
 		return ret;
 	}

 	for (actual = 0; actual < len; actual += chunk_len) {
 		chunk_len = min(len - actual, page_size - (addr % page_size));

 		/* Use the same address bits for both commands */
 		cmd[0] = CMD_AT45_LOAD_BUF1;
 		cmd[1] = addr >> 16;
 		cmd[2] = addr >> 8;
 		cmd[3] = addr;

 		ret = spi_flash_cmd_write(flash->spi, cmd, 4,
 				buf + actual, chunk_len);
 		if (ret < 0) {
 			debug("SF: Loading AT45 buffer failed\n");
 			goto out;
 		}

 		cmd[0] = CMD_AT45_PROG_BUF1;
 		ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
 		if (ret < 0) {
 			debug("SF: AT45 page programming failed\n");
 			goto out;
 		}

 		ret = at45_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
 		if (ret < 0) {
 			debug("SF: AT45 page programming timed out\n");
 			goto out;
 		}

 		addr += chunk_len;
 	}

 	debug("SF: AT45: Successfully programmed %zu bytes @ 0x%x\n",
 	      len, offset);
 	ret = 0;

 out:
 	spi_release_bus(flash->spi);
 	return ret;
 }

 static int dataflash_write_at45(struct spi_flash *flash,
 		u32 offset, size_t len, const void *buf)
 {
 	struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
 	unsigned long page_addr;
 	unsigned long byte_addr;
 	unsigned long page_size;
 	unsigned int page_shift;
 	size_t chunk_len;
 	size_t actual;
 	int ret;
 	u8 cmd[4];

 	/*
 	 * TODO: This function currently uses only page buffer #1.  We can
 	 * speed this up by using both buffers and loading one buffer while
 	 * the other is being programmed into main memory.
 	 */

 	page_shift = asf->params->l2_page_size;
 	page_size = (1 << page_shift) + (1 << (page_shift - 5));
 	page_shift++;
 	page_addr = offset / page_size;
 	byte_addr = offset % page_size;

 	ret = spi_claim_bus(flash->spi);
 	if (ret) {
 		debug("SF: Unable to claim SPI bus\n");
 		return ret;
 	}

 	for (actual = 0; actual < len; actual += chunk_len) {
 		chunk_len = min(len - actual, page_size - byte_addr);

 		/* Use the same address bits for both commands */
 		cmd[0] = CMD_AT45_LOAD_BUF1;
 		cmd[1] = page_addr >> (16 - page_shift);
 		cmd[2] = page_addr << (page_shift - 8) | (byte_addr >> 8);
 		cmd[3] = byte_addr;

 		ret = spi_flash_cmd_write(flash->spi, cmd, 4,
 				buf + actual, chunk_len);
 		if (ret < 0) {
 			debug("SF: Loading AT45 buffer failed\n");
 			goto out;
 		}

 		cmd[0] = CMD_AT45_PROG_BUF1;
 		ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
 		if (ret < 0) {
 			debug("SF: AT45 page programming failed\n");
 			goto out;
 		}

 		ret = at45_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
 		if (ret < 0) {
 			debug("SF: AT45 page programming timed out\n");
 			goto out;
 		}

 		page_addr++;
 		byte_addr = 0;
 	}

 	debug("SF: AT45: Successfully programmed %zu bytes @ 0x%x\n",
 	      len, offset);
 	ret = 0;

 out:
 	spi_release_bus(flash->spi);
 	return ret;
 }

 /*
  * TODO: the two erase funcs (_p2/_at45) should get unified ...
  */
 static int dataflash_erase_p2(struct spi_flash *flash, u32 offset, size_t len)
 {
 	struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
 	unsigned long page_size;

 	size_t actual;
 	int ret;
 	u8 cmd[4];

 	/*
 	 * TODO: This function currently uses page erase only. We can
 	 * probably speed things up by using block and/or sector erase
 	 * when possible.
 	 */

 	page_size = (1 << asf->params->l2_page_size);

 	if (offset % page_size || len % page_size) {
 		debug("SF: Erase offset/length not multiple of page size\n");
 		return -1;
 	}

 	cmd[0] = CMD_AT45_ERASE_PAGE;
 	cmd[3] = 0x00;

 	ret = spi_claim_bus(flash->spi);
 	if (ret) {
 		debug("SF: Unable to claim SPI bus\n");
 		return ret;
 	}

 	for (actual = 0; actual < len; actual += page_size) {
 		cmd[1] = offset >> 16;
 		cmd[2] = offset >> 8;

 		ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
 		if (ret < 0) {
 			debug("SF: AT45 page erase failed\n");
 			goto out;
 		}

 		ret = at45_wait_ready(flash, SPI_FLASH_PAGE_ERASE_TIMEOUT);
 		if (ret < 0) {
 			debug("SF: AT45 page erase timed out\n");
 			goto out;
 		}

 		offset += page_size;
 	}

 	debug("SF: AT45: Successfully erased %zu bytes @ 0x%x\n",
 	      len, offset);
 	ret = 0;

 out:
 	spi_release_bus(flash->spi);
 	return ret;
 }

 static int dataflash_erase_at45(struct spi_flash *flash, u32 offset, size_t len)
 {
 	struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
 	unsigned long page_addr;
 	unsigned long page_size;
 	unsigned int page_shift;
 	size_t actual;
 	int ret;
 	u8 cmd[4];

 	/*
 	 * TODO: This function currently uses page erase only. We can
 	 * probably speed things up by using block and/or sector erase
 	 * when possible.
 	 */

 	page_shift = asf->params->l2_page_size;
 	page_size = (1 << page_shift) + (1 << (page_shift - 5));
 	page_shift++;
 	page_addr = offset / page_size;

 	if (offset % page_size || len % page_size) {
 		debug("SF: Erase offset/length not multiple of page size\n");
 		return -1;
 	}

 	cmd[0] = CMD_AT45_ERASE_PAGE;
 	cmd[3] = 0x00;

 	ret = spi_claim_bus(flash->spi);
 	if (ret) {
 		debug("SF: Unable to claim SPI bus\n");
 		return ret;
 	}

 	for (actual = 0; actual < len; actual += page_size) {
 		cmd[1] = page_addr >> (16 - page_shift);
 		cmd[2] = page_addr << (page_shift - 8);

 		ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
 		if (ret < 0) {
 			debug("SF: AT45 page erase failed\n");
 			goto out;
 		}

 		ret = at45_wait_ready(flash, SPI_FLASH_PAGE_ERASE_TIMEOUT);
 		if (ret < 0) {
 			debug("SF: AT45 page erase timed out\n");
 			goto out;
 		}

 		page_addr++;
 	}

 	debug("SF: AT45: Successfully erased %zu bytes @ 0x%x\n",
 	      len, offset);
 	ret = 0;

 out:
 	spi_release_bus(flash->spi);
 	return ret;
 }

 struct spi_flash *spi_flash_probe_atmel(struct spi_slave *spi, u8 *idcode)
 {
 	const struct atmel_spi_flash_params *params;
 	unsigned page_size;
 	unsigned int family;
 	struct atmel_spi_flash *asf;
 	unsigned int i;
 	int ret;
 	u8 status;

 	for (i = 0; i < ARRAY_SIZE(atmel_spi_flash_table); i++) {
 		params = &atmel_spi_flash_table[i];
 		if (params->idcode1 == idcode[1])
 			break;
 	}

 	if (i == ARRAY_SIZE(atmel_spi_flash_table)) {
 		debug("SF: Unsupported DataFlash ID %02x\n",
 		      idcode[1]);
 		return NULL;
 	}

 	asf = spi_flash_alloc(struct atmel_spi_flash, spi, params->name);
 	if (!asf) {
 		debug("SF: Failed to allocate memory\n");
 		return NULL;
 	}

 	asf->params = params;

 	/* Assuming power-of-two page size initially. */
 	page_size = 1 << params->l2_page_size;

 	family = idcode[1] >> 5;

 	switch (family) {
 	case DF_FAMILY_AT45:
 		/*
 		 * AT45 chips have configurable page size. The status
 		 * register indicates which configuration is active.
 		 */
 		ret = spi_flash_cmd(spi, CMD_AT45_READ_STATUS, &status, 1);
 		if (ret)
 			goto err;

 		debug("SF: AT45 status register: %02x\n", status);

 		if (!(status & AT45_STATUS_P2_PAGE_SIZE)) {
 			asf->flash.read = dataflash_read_fast_at45;
 			asf->flash.write = dataflash_write_at45;
 			asf->flash.erase = dataflash_erase_at45;
 			page_size += 1 << (params->l2_page_size - 5);
 		} else {
 			asf->flash.write = dataflash_write_p2;
 			asf->flash.erase = dataflash_erase_p2;
 		}

 		asf->flash.page_size = page_size;
 		asf->flash.sector_size = page_size;
 		break;

 	case DF_FAMILY_AT26F:
 	case DF_FAMILY_AT26DF:
 		asf->flash.page_size = page_size;
 		asf->flash.sector_size = 4096;
 		/* clear SPRL# bit for locked flash */
 		spi_flash_cmd_write_status(&asf->flash, 0);
 		break;

 	default:
 		debug("SF: Unsupported DataFlash family %u\n", family);
 		goto err;
 	}

 	asf->flash.size = page_size * params->pages_per_block
 				* params->blocks_per_sector
 				* params->nr_sectors;

 	return &asf->flash;

 err:
 	free(asf);
 	return NULL;
 }
	/*
	* Atmel SPI DataFlash support
	*
	* Copyright (C) 2008 Atmel Corporation
	* Licensed under the GPL-2 or later.
	*/

	#include <common.h>
	#include <malloc.h>
	#include <spi_flash.h>

	#include "spi_flash_internal.h"

	/* AT45-specific commands */
	#define CMD_AT45_READ_STATUS 0xd7
	#define CMD_AT45_ERASE_PAGE 0x81
	#define CMD_AT45_LOAD_PROG_BUF1 0x82
	#define CMD_AT45_LOAD_BUF1 0x84
	#define CMD_AT45_LOAD_PROG_BUF2 0x85
	#define CMD_AT45_LOAD_BUF2 0x87
	#define CMD_AT45_PROG_BUF1 0x88
	#define CMD_AT45_PROG_BUF2 0x89

	/* AT45 status register bits */
	#define AT45_STATUS_P2_PAGE_SIZE (1 << 0)
	#define AT45_STATUS_READY (1 << 7)

	/* DataFlash family IDs, as obtained from the second idcode byte */
	#define DF_FAMILY_AT26F 0
	#define DF_FAMILY_AT45 1
	#define DF_FAMILY_AT26DF 2 /* AT25DF and AT26DF */

	struct atmel_spi_flash_params {
	u8 idcode1;
	/* Log2 of page size in power-of-two mode */
	u8 l2_page_size;
	u8 pages_per_block;
	u8 blocks_per_sector;
	u8 nr_sectors;
	const char *name;
	};

	/* spi_flash needs to be first so upper layers can free() it */
	struct atmel_spi_flash {
	struct spi_flash flash;
	const struct atmel_spi_flash_params *params;
	};

	static inline struct atmel_spi_flash *
	to_atmel_spi_flash(struct spi_flash *flash)
	{
	return container_of(flash, struct atmel_spi_flash, flash);
	}

	static const struct atmel_spi_flash_params atmel_spi_flash_table[] = {
	{
	.idcode1 = 0x22,
	.l2_page_size = 8,
	.pages_per_block = 8,
	.blocks_per_sector = 16,
	.nr_sectors = 4,
	.name = "AT45DB011D",
	},
	{
	.idcode1 = 0x23,
	.l2_page_size = 8,
	.pages_per_block = 8,
	.blocks_per_sector = 16,
	.nr_sectors = 8,
	.name = "AT45DB021D",
	},
	{
	.idcode1 = 0x24,
	.l2_page_size = 8,
	.pages_per_block = 8,
	.blocks_per_sector = 32,
	.nr_sectors = 8,
	.name = "AT45DB041D",
	},
	{
	.idcode1 = 0x25,
	.l2_page_size = 8,
	.pages_per_block = 8,
	.blocks_per_sector = 32,
	.nr_sectors = 16,
	.name = "AT45DB081D",
	},
	{
	.idcode1 = 0x26,
	.l2_page_size = 9,
	.pages_per_block = 8,
	.blocks_per_sector = 32,
	.nr_sectors = 16,
	.name = "AT45DB161D",
	},
	{
	.idcode1 = 0x27,
	.l2_page_size = 9,
	.pages_per_block = 8,
	.blocks_per_sector = 64,
	.nr_sectors = 64,
	.name = "AT45DB321D",
	},
	{
	.idcode1 = 0x28,
	.l2_page_size = 10,
	.pages_per_block = 8,
	.blocks_per_sector = 32,
	.nr_sectors = 32,
	.name = "AT45DB642D",
	},
	{
	.idcode1 = 0x47,
	.l2_page_size = 8,
	.pages_per_block = 16,
	.blocks_per_sector = 16,
	.nr_sectors = 64,
	.name = "AT25DF321",
	},
	};

	static int at45_wait_ready(struct spi_flash *flash, unsigned long timeout)
	{
	struct spi_slave *spi = flash->spi;
	unsigned long timebase;
	int ret;
	u8 cmd = CMD_AT45_READ_STATUS;
	u8 status;

	timebase = get_timer(0);

	ret = spi_xfer(spi, 8, &cmd, NULL, SPI_XFER_BEGIN);
	if (ret)
	return -1;

	do {
	ret = spi_xfer(spi, 8, NULL, &status, 0);
	if (ret)
	return -1;

	if (status & AT45_STATUS_READY)
	break;
	} while (get_timer(timebase) < timeout);

	/* Deactivate CS */
	spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);

	if (status & AT45_STATUS_READY)
	return 0;

	/* Timed out */
	return -1;
	}

	/*
	* Assemble the address part of a command for AT45 devices in
	* non-power-of-two page size mode.
	*/
	static void at45_build_address(struct atmel_spi_flash asf, u8 cmd, u32 offset)
	{
	unsigned long page_addr;
	unsigned long byte_addr;
	unsigned long page_size;
	unsigned int page_shift;

	/*
	* The "extra" space per page is the power-of-two page size
	* divided by 32.
	*/
	page_shift = asf->params->l2_page_size;
	page_size = (1 << page_shift) + (1 << (page_shift - 5));
	page_shift++;
	page_addr = offset / page_size;
	byte_addr = offset % page_size;

	cmd[0] = page_addr >> (16 - page_shift);
	cmd[1] = page_addr << (page_shift - 8) \| (byte_addr >> 8);
	cmd[2] = byte_addr;
	}

	static int dataflash_read_fast_at45(struct spi_flash *flash,
	u32 offset, size_t len, void *buf)
	{
	struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
	u8 cmd[5];

	cmd[0] = CMD_READ_ARRAY_FAST;
	at45_build_address(asf, cmd + 1, offset);
	cmd[4] = 0x00;

	return spi_flash_read_common(flash, cmd, sizeof(cmd), buf, len);
	}

	/*
	* TODO: the two write funcs (_p2/_at45) should get unified ...
	*/
	static int dataflash_write_p2(struct spi_flash *flash,
	u32 offset, size_t len, const void *buf)
	{
	struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
	unsigned long page_size;
	u32 addr = offset;
	size_t chunk_len;
	size_t actual;
	int ret;
	u8 cmd[4];

	/*
	* TODO: This function currently uses only page buffer #1. We can
	* speed this up by using both buffers and loading one buffer while
	* the other is being programmed into main memory.
	*/

	page_size = (1 << asf->params->l2_page_size);

	ret = spi_claim_bus(flash->spi);
	if (ret) {
	debug("SF: Unable to claim SPI bus\n");
	return ret;
	}

	for (actual = 0; actual < len; actual += chunk_len) {
	chunk_len = min(len - actual, page_size - (addr % page_size));

	/* Use the same address bits for both commands */
	cmd[0] = CMD_AT45_LOAD_BUF1;
	cmd[1] = addr >> 16;
	cmd[2] = addr >> 8;
	cmd[3] = addr;

	ret = spi_flash_cmd_write(flash->spi, cmd, 4,
	buf + actual, chunk_len);
	if (ret < 0) {
	debug("SF: Loading AT45 buffer failed\n");
	goto out;
	}

	cmd[0] = CMD_AT45_PROG_BUF1;
	ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
	if (ret < 0) {
	debug("SF: AT45 page programming failed\n");
	goto out;
	}

	ret = at45_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
	if (ret < 0) {
	debug("SF: AT45 page programming timed out\n");
	goto out;
	}

	addr += chunk_len;
	}

	debug("SF: AT45: Successfully programmed %zu bytes @ 0x%x\n",
	len, offset);
	ret = 0;

	out:
	spi_release_bus(flash->spi);
	return ret;
	}

	static int dataflash_write_at45(struct spi_flash *flash,
	u32 offset, size_t len, const void *buf)
	{
	struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
	unsigned long page_addr;
	unsigned long byte_addr;
	unsigned long page_size;
	unsigned int page_shift;
	size_t chunk_len;
	size_t actual;
	int ret;
	u8 cmd[4];

	/*
	* TODO: This function currently uses only page buffer #1. We can
	* speed this up by using both buffers and loading one buffer while
	* the other is being programmed into main memory.
	*/

	page_shift = asf->params->l2_page_size;
	page_size = (1 << page_shift) + (1 << (page_shift - 5));
	page_shift++;
	page_addr = offset / page_size;
	byte_addr = offset % page_size;

	ret = spi_claim_bus(flash->spi);
	if (ret) {
	debug("SF: Unable to claim SPI bus\n");
	return ret;
	}

	for (actual = 0; actual < len; actual += chunk_len) {
	chunk_len = min(len - actual, page_size - byte_addr);

	/* Use the same address bits for both commands */
	cmd[0] = CMD_AT45_LOAD_BUF1;
	cmd[1] = page_addr >> (16 - page_shift);
	cmd[2] = page_addr << (page_shift - 8) \| (byte_addr >> 8);
	cmd[3] = byte_addr;

	ret = spi_flash_cmd_write(flash->spi, cmd, 4,
	buf + actual, chunk_len);
	if (ret < 0) {
	debug("SF: Loading AT45 buffer failed\n");
	goto out;
	}

	cmd[0] = CMD_AT45_PROG_BUF1;
	ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
	if (ret < 0) {
	debug("SF: AT45 page programming failed\n");
	goto out;
	}

	ret = at45_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
	if (ret < 0) {
	debug("SF: AT45 page programming timed out\n");
	goto out;
	}

	page_addr++;
	byte_addr = 0;
	}

	debug("SF: AT45: Successfully programmed %zu bytes @ 0x%x\n",
	len, offset);
	ret = 0;

	out:
	spi_release_bus(flash->spi);
	return ret;
	}

	/*
	* TODO: the two erase funcs (_p2/_at45) should get unified ...
	*/
	static int dataflash_erase_p2(struct spi_flash *flash, u32 offset, size_t len)
	{
	struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
	unsigned long page_size;

	size_t actual;
	int ret;
	u8 cmd[4];

	/*
	* TODO: This function currently uses page erase only. We can
	* probably speed things up by using block and/or sector erase
	* when possible.
	*/

	page_size = (1 << asf->params->l2_page_size);

	if (offset % page_size \|\| len % page_size) {
	debug("SF: Erase offset/length not multiple of page size\n");
	return -1;
	}

	cmd[0] = CMD_AT45_ERASE_PAGE;
	cmd[3] = 0x00;

	ret = spi_claim_bus(flash->spi);
	if (ret) {
	debug("SF: Unable to claim SPI bus\n");
	return ret;
	}

	for (actual = 0; actual < len; actual += page_size) {
	cmd[1] = offset >> 16;
	cmd[2] = offset >> 8;

	ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
	if (ret < 0) {
	debug("SF: AT45 page erase failed\n");
	goto out;
	}

	ret = at45_wait_ready(flash, SPI_FLASH_PAGE_ERASE_TIMEOUT);
	if (ret < 0) {
	debug("SF: AT45 page erase timed out\n");
	goto out;
	}

	offset += page_size;
	}

	debug("SF: AT45: Successfully erased %zu bytes @ 0x%x\n",
	len, offset);
	ret = 0;

	out:
	spi_release_bus(flash->spi);
	return ret;
	}

	static int dataflash_erase_at45(struct spi_flash *flash, u32 offset, size_t len)
	{
	struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
	unsigned long page_addr;
	unsigned long page_size;
	unsigned int page_shift;
	size_t actual;
	int ret;
	u8 cmd[4];

	/*
	* TODO: This function currently uses page erase only. We can
	* probably speed things up by using block and/or sector erase
	* when possible.
	*/

	page_shift = asf->params->l2_page_size;
	page_size = (1 << page_shift) + (1 << (page_shift - 5));
	page_shift++;
	page_addr = offset / page_size;

	if (offset % page_size \|\| len % page_size) {
	debug("SF: Erase offset/length not multiple of page size\n");
	return -1;
	}

	cmd[0] = CMD_AT45_ERASE_PAGE;
	cmd[3] = 0x00;

	ret = spi_claim_bus(flash->spi);
	if (ret) {
	debug("SF: Unable to claim SPI bus\n");
	return ret;
	}

	for (actual = 0; actual < len; actual += page_size) {
	cmd[1] = page_addr >> (16 - page_shift);
	cmd[2] = page_addr << (page_shift - 8);

	ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
	if (ret < 0) {
	debug("SF: AT45 page erase failed\n");
	goto out;
	}

	ret = at45_wait_ready(flash, SPI_FLASH_PAGE_ERASE_TIMEOUT);
	if (ret < 0) {
	debug("SF: AT45 page erase timed out\n");
	goto out;
	}

	page_addr++;
	}

	debug("SF: AT45: Successfully erased %zu bytes @ 0x%x\n",
	len, offset);
	ret = 0;

	out:
	spi_release_bus(flash->spi);
	return ret;
	}

	struct spi_flash spi_flash_probe_atmel(struct spi_slave spi, u8 *idcode)
	{
	const struct atmel_spi_flash_params *params;
	unsigned page_size;
	unsigned int family;
	struct atmel_spi_flash *asf;
	unsigned int i;
	int ret;
	u8 status;

	for (i = 0; i < ARRAY_SIZE(atmel_spi_flash_table); i++) {
	params = &atmel_spi_flash_table[i];
	if (params->idcode1 == idcode[1])
	break;
	}

	if (i == ARRAY_SIZE(atmel_spi_flash_table)) {
	debug("SF: Unsupported DataFlash ID %02x\n",
	idcode[1]);
	return NULL;
	}

	asf = spi_flash_alloc(struct atmel_spi_flash, spi, params->name);
	if (!asf) {
	debug("SF: Failed to allocate memory\n");
	return NULL;
	}

	asf->params = params;

	/* Assuming power-of-two page size initially. */
	page_size = 1 << params->l2_page_size;

	family = idcode[1] >> 5;

	switch (family) {
	case DF_FAMILY_AT45:
	/*
	* AT45 chips have configurable page size. The status
	* register indicates which configuration is active.
	*/
	ret = spi_flash_cmd(spi, CMD_AT45_READ_STATUS, &status, 1);
	if (ret)
	goto err;

	debug("SF: AT45 status register: %02x\n", status);

	if (!(status & AT45_STATUS_P2_PAGE_SIZE)) {
	asf->flash.read = dataflash_read_fast_at45;
	asf->flash.write = dataflash_write_at45;
	asf->flash.erase = dataflash_erase_at45;
	page_size += 1 << (params->l2_page_size - 5);
	} else {
	asf->flash.write = dataflash_write_p2;
	asf->flash.erase = dataflash_erase_p2;
	}

	asf->flash.page_size = page_size;
	asf->flash.sector_size = page_size;
	break;

	case DF_FAMILY_AT26F:
	case DF_FAMILY_AT26DF:
	asf->flash.page_size = page_size;
	asf->flash.sector_size = 4096;
	/* clear SPRL# bit for locked flash */
	spi_flash_cmd_write_status(&asf->flash, 0);
	break;

	default:
	debug("SF: Unsupported DataFlash family %u\n", family);
	goto err;
	}

	asf->flash.size = page_size * params->pages_per_block
	* params->blocks_per_sector
	* params->nr_sectors;

	return &asf->flash;

	err:
	free(asf);
	return NULL;
	}