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Commit 837479d2 authored by Anton Vorontsov's avatar Anton Vorontsov Committed by David Woodhouse
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mtd: m25p80: Add support for CAT25xxx serial EEPROMs 



CAT25 chips (as manufactured by On Semiconductor, previously Catalyst
Semiconductor) are similar to the original M25Px0 chips, except:

- Address width can vary (1-2 bytes, in contrast to 3 bytes in M25P
  chips). So, implement convenient m25p_addr2cmd() and m25p_cmdsz()
  calls, and place address width information into flash_info struct;

- Page size can vary, therefore we shouldn't hardcode it, so get rid
  of FLASH_PAGESIZE definition, and place the page size information
  into flash_info struct;

- CAT25 EEPROMs don't need to be erased, so add NO_ERASE flag, and
  propagate it to the mtd subsystem.

[dwmw2: Fix up for conflicts with DMA safety patch]
Signed-off-by: default avatarAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 18c6182b

drivers/mtd/devices/m25p80.c

+69 −45
Original line number Diff line number Diff line
@@ -29,9 +29,6 @@ 
#include <linux/spi/spi.h>

#include <linux/spi/flash.h>





#define FLASH_PAGESIZE		256



/* Flash opcodes. */

#define	OPCODE_WREN		0x06	/* Write enable */

#define	OPCODE_RDSR		0x05	/* Read status register */
@@ -61,7 +58,7 @@ 


/* Define max times to check status register before we give up. */

#define	MAX_READY_WAIT_JIFFIES	(40 * HZ)	/* M25P16 specs 40s max chip erase */

#define	CMD_SIZE		4

#define	MAX_CMD_SIZE		4



#ifdef CONFIG_M25PXX_USE_FAST_READ

#define OPCODE_READ 	OPCODE_FAST_READ
@@ -78,6 +75,8 @@ struct m25p { 
	struct mutex		lock;

	struct mtd_info		mtd;

	unsigned		partitioned:1;

	u16			page_size;

	u16			addr_width;

	u8			erase_opcode;

	u8			*command;

};
@@ -198,6 +197,19 @@ static int erase_chip(struct m25p *flash) 
	return 0;

}



static void m25p_addr2cmd(struct m25p *flash, unsigned int addr, u8 *cmd)

{

	/* opcode is in cmd[0] */

	cmd[1] = addr >> (flash->addr_width * 8 -  8);

	cmd[2] = addr >> (flash->addr_width * 8 - 16);

	cmd[3] = addr >> (flash->addr_width * 8 - 24);

}



static int m25p_cmdsz(struct m25p *flash)

{

	return 1 + flash->addr_width;

}



/*

 * Erase one sector of flash memory at offset ``offset'' which is any

 * address within the sector which should be erased.
@@ -219,11 +231,9 @@ static int erase_sector(struct m25p *flash, u32 offset) 


	/* Set up command buffer. */

	flash->command[0] = flash->erase_opcode;

	flash->command[1] = offset >> 16;

	flash->command[2] = offset >> 8;

	flash->command[3] = offset;

	m25p_addr2cmd(flash, offset, flash->command);



	spi_write(flash->spi, flash->command, CMD_SIZE);

	spi_write(flash->spi, flash->command, m25p_cmdsz(flash));



	return 0;

}
@@ -325,7 +335,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len, 
	 * Should add 1 byte DUMMY_BYTE.

	 */

	t[0].tx_buf = flash->command;

	t[0].len = CMD_SIZE + FAST_READ_DUMMY_BYTE;

	t[0].len = m25p_cmdsz(flash) + FAST_READ_DUMMY_BYTE;

	spi_message_add_tail(&t[0], &m);



	t[1].rx_buf = buf;
@@ -352,13 +362,11 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len, 


	/* Set up the write data buffer. */

	flash->command[0] = OPCODE_READ;

	flash->command[1] = from >> 16;

	flash->command[2] = from >> 8;

	flash->command[3] = from;

	m25p_addr2cmd(flash, from, flash->command);



	spi_sync(flash->spi, &m);



	*retlen = m.actual_length - CMD_SIZE - FAST_READ_DUMMY_BYTE;

	*retlen = m.actual_length - m25p_cmdsz(flash) - FAST_READ_DUMMY_BYTE;



	mutex_unlock(&flash->lock);
@@ -396,7 +404,7 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len, 
	memset(t, 0, (sizeof t));



	t[0].tx_buf = flash->command;

	t[0].len = CMD_SIZE;

	t[0].len = m25p_cmdsz(flash);

	spi_message_add_tail(&t[0], &m);



	t[1].tx_buf = buf;
@@ -414,41 +422,36 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len, 


	/* Set up the opcode in the write buffer. */

	flash->command[0] = OPCODE_PP;

	flash->command[1] = to >> 16;

	flash->command[2] = to >> 8;

	flash->command[3] = to;

	m25p_addr2cmd(flash, to, flash->command);



	/* what page do we start with? */

	page_offset = to % FLASH_PAGESIZE;

	page_offset = to & (flash->page_size - 1);



	/* do all the bytes fit onto one page? */

	if (page_offset + len <= FLASH_PAGESIZE) {

	if (page_offset + len <= flash->page_size) {

		t[1].len = len;



		spi_sync(flash->spi, &m);



		*retlen = m.actual_length - CMD_SIZE;

		*retlen = m.actual_length - m25p_cmdsz(flash);

	} else {

		u32 i;



		/* the size of data remaining on the first page */

		page_size = FLASH_PAGESIZE - page_offset;

		page_size = flash->page_size - page_offset;



		t[1].len = page_size;

		spi_sync(flash->spi, &m);



		*retlen = m.actual_length - CMD_SIZE;

		*retlen = m.actual_length - m25p_cmdsz(flash);



		/* write everything in PAGESIZE chunks */

		/* write everything in flash->page_size chunks */

		for (i = page_size; i < len; i += page_size) {

			page_size = len - i;

			if (page_size > FLASH_PAGESIZE)

				page_size = FLASH_PAGESIZE;

			if (page_size > flash->page_size)

				page_size = flash->page_size;



			/* write the next page to flash */

			flash->command[1] = (to + i) >> 16;

			flash->command[2] = (to + i) >> 8;

			flash->command[3] = (to + i);

			m25p_addr2cmd(flash, to + i, flash->command);



			t[1].tx_buf = buf + i;

			t[1].len = page_size;
@@ -460,7 +463,7 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len, 
			spi_sync(flash->spi, &m);



			if (retlen)

				*retlen += m.actual_length - CMD_SIZE;

				*retlen += m.actual_length - m25p_cmdsz(flash);

		}

	}
@@ -492,7 +495,7 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len, 
	memset(t, 0, (sizeof t));



	t[0].tx_buf = flash->command;

	t[0].len = CMD_SIZE;

	t[0].len = m25p_cmdsz(flash);

	spi_message_add_tail(&t[0], &m);



	t[1].tx_buf = buf;
@@ -511,9 +514,7 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len, 
	/* Start write from odd address. */

	if (actual) {

		flash->command[0] = OPCODE_BP;

		flash->command[1] = to >> 16;

		flash->command[2] = to >> 8;

		flash->command[3] = to;

		m25p_addr2cmd(flash, to, flash->command);



		/* write one byte. */

		t[1].len = 1;
@@ -521,17 +522,15 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len, 
		ret = wait_till_ready(flash);

		if (ret)

			goto time_out;

		*retlen += m.actual_length - CMD_SIZE;

		*retlen += m.actual_length - m25p_cmdsz(flash);

	}

	to += actual;



	flash->command[0] = OPCODE_AAI_WP;

	flash->command[1] = to >> 16;

	flash->command[2] = to >> 8;

	flash->command[3] = to;

	m25p_addr2cmd(flash, to, flash->command);



	/* Write out most of the data here. */

	cmd_sz = CMD_SIZE;

	cmd_sz = m25p_cmdsz(flash);

	for (; actual < len - 1; actual += 2) {

		t[0].len = cmd_sz;

		/* write two bytes. */
@@ -555,10 +554,8 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len, 
	if (actual != len) {

		write_enable(flash);

		flash->command[0] = OPCODE_BP;

		flash->command[1] = to >> 16;

		flash->command[2] = to >> 8;

		flash->command[3] = to;

		t[0].len = CMD_SIZE;

		m25p_addr2cmd(flash, to, flash->command);

		t[0].len = m25p_cmdsz(flash);

		t[1].len = 1;

		t[1].tx_buf = buf + actual;
@@ -566,7 +563,7 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len, 
		ret = wait_till_ready(flash);

		if (ret)

			goto time_out;

		*retlen += m.actual_length - CMD_SIZE;

		*retlen += m.actual_length - m25p_cmdsz(flash);

		write_disable(flash);

	}
@@ -595,8 +592,12 @@ struct flash_info { 
	unsigned	sector_size;

	u16		n_sectors;



	u16		page_size;

	u16		addr_width;



	u16		flags;

#define	SECT_4K		0x01		/* OPCODE_BE_4K works uniformly */

#define	M25P_NO_ERASE	0x02		/* No erase command needed */

};



#define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags)	\
@@ -605,9 +606,20 @@ struct flash_info { 
		.ext_id = (_ext_id),					\

		.sector_size = (_sector_size),				\

		.n_sectors = (_n_sectors),				\

		.page_size = 256,					\

		.addr_width = 3,					\

		.flags = (_flags),					\

	})



#define CAT25_INFO(_sector_size, _n_sectors, _page_size, _addr_width)	\

	((kernel_ulong_t)&(struct flash_info) {				\

		.sector_size = (_sector_size),				\

		.n_sectors = (_n_sectors),				\

		.page_size = (_page_size),				\

		.addr_width = (_addr_width),				\

		.flags = M25P_NO_ERASE,					\

	})



/* NOTE: double check command sets and memory organization when you add

 * more flash chips.  This current list focusses on newer chips, which

 * have been converging on command sets which including JEDEC ID.
@@ -680,6 +692,13 @@ static const struct spi_device_id m25p_ids[] = { 
	{ "w25x16", INFO(0xef3015, 0, 64 * 1024,  32, SECT_4K) },

	{ "w25x32", INFO(0xef3016, 0, 64 * 1024,  64, SECT_4K) },

	{ "w25x64", INFO(0xef3017, 0, 64 * 1024, 128, SECT_4K) },



	/* Catalyst / On Semiconductor -- non-JEDEC */

	{ "cat25c11", CAT25_INFO(  16, 8, 16, 1) },

	{ "cat25c03", CAT25_INFO(  32, 8, 16, 2) },

	{ "cat25c09", CAT25_INFO( 128, 8, 32, 2) },

	{ "cat25c17", CAT25_INFO( 256, 8, 32, 2) },

	{ "cat25128", CAT25_INFO(2048, 8, 64, 2) },

	{ },

};

MODULE_DEVICE_TABLE(spi, m25p_ids);
@@ -793,7 +812,7 @@ static int __devinit m25p_probe(struct spi_device *spi) 
	flash = kzalloc(sizeof *flash, GFP_KERNEL);

	if (!flash)

		return -ENOMEM;

	flash->command = kmalloc(CMD_SIZE + FAST_READ_DUMMY_BYTE, GFP_KERNEL);

	flash->command = kmalloc(MAX_CMD_SIZE + FAST_READ_DUMMY_BYTE, GFP_KERNEL);

	if (!flash->command) {

		kfree(flash);

		return -ENOMEM;
@@ -841,7 +860,12 @@ static int __devinit m25p_probe(struct spi_device *spi) 
		flash->mtd.erasesize = info->sector_size;

	}



	if (info->flags & M25P_NO_ERASE)

		flash->mtd.flags |= MTD_NO_ERASE;



	flash->mtd.dev.parent = &spi->dev;

	flash->page_size = info->page_size;

	flash->addr_width = info->addr_width;



	dev_info(&spi->dev, "%s (%lld Kbytes)\n", id->name,

			(long long)flash->mtd.size >> 10);