Commit 471f717a authored by David Woodhouse's avatar David Woodhouse
Browse files

Revert "[MTD] Driver for AT26Fxxx dataflash devices" 



This reverts commit 340ea370.

It's not needed given the other m25p80 patch (which now handles
at26 "dataflash" as well as most other standard SPI flash chips),
and requires a controller driver that won't be merged upstream
(supplanted by drivers/spi/atmel_spi.c) ... the submitter of
that at91_dataflash26.c driver concurred.

Requested by David Brownell <david-b@pacbell.net>
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
parent f2d40cd9

drivers/mtd/devices/Kconfig

+0 −8
Original line number Diff line number Diff line
@@ -60,14 +60,6 @@ config MTD_DATAFLASH 
	  Sometimes DataFlash chips are packaged inside MMC-format

	  cards; at this writing, the MMC stack won't handle those.



config MTD_DATAFLASH26

	tristate "AT91RM9200 DataFlash AT26xxx"

	depends on MTD && ARCH_AT91RM9200 && AT91_SPI

	help

	  This enables access to the DataFlash chip (AT26xxx) on an

	  AT91RM9200-based board.

	  If you have such a board and such a DataFlash, say 'Y'.



config MTD_M25P80

	tristate "Support most SPI Flash chips (AT26DF, M25P, W25X, ...)"

	depends on SPI_MASTER && EXPERIMENTAL

drivers/mtd/devices/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -16,5 +16,4 @@ obj-$(CONFIG_MTD_MTDRAM) += mtdram.o 
obj-$(CONFIG_MTD_LART)		+= lart.o

obj-$(CONFIG_MTD_BLOCK2MTD)	+= block2mtd.o

obj-$(CONFIG_MTD_DATAFLASH)	+= mtd_dataflash.o

obj-$(CONFIG_MTD_DATAFLASH26)	+= at91_dataflash26.o

obj-$(CONFIG_MTD_M25P80)	+= m25p80.o

drivers/mtd/devices/at91_dataflash26.c

deleted100644 → 0
+0 −485
Original line number Diff line number Diff line 
/*

 * Atmel DataFlash driver for Atmel AT91RM9200 (Thunder)

 * This is a largely modified version of at91_dataflash.c that

 * supports AT26xxx dataflash chips. The original driver supports

 * AT45xxx chips.

 *

 * Note: This driver was only tested with an AT26F004. It should be

 * easy to make it work with other AT26xxx dataflash devices, though.

 *

 * Copyright (C) 2007 Hans J. Koch <hjk@linutronix.de>

 * original Copyright (C) SAN People (Pty) Ltd

 *

 * 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.

*/



#include <linux/config.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/mtd/mtd.h>



#include <asm/arch/at91_spi.h>



#define DATAFLASH_MAX_DEVICES	4	/* max number of dataflash devices */



#define MANUFACTURER_ID_ATMEL		0x1F



/* command codes */



#define AT26_OP_READ_STATUS		0x05

#define AT26_OP_READ_DEV_ID		0x9F

#define AT26_OP_ERASE_PAGE_4K		0x20

#define AT26_OP_READ_ARRAY_FAST		0x0B

#define AT26_OP_SEQUENTIAL_WRITE	0xAF

#define AT26_OP_WRITE_ENABLE		0x06

#define AT26_OP_WRITE_DISABLE		0x04

#define AT26_OP_SECTOR_PROTECT		0x36

#define AT26_OP_SECTOR_UNPROTECT	0x39



/* status register bits */



#define AT26_STATUS_BUSY		0x01

#define AT26_STATUS_WRITE_ENABLE	0x02



struct dataflash_local

{

	int spi;			/* SPI chip-select number */

	unsigned int page_size;		/* number of bytes per page */

};





/* Detected DataFlash devices */

static struct mtd_info* mtd_devices[DATAFLASH_MAX_DEVICES];

static int nr_devices = 0;



/* Allocate a single SPI transfer descriptor.  We're assuming that if multiple

   SPI transfers occur at the same time, spi_access_bus() will serialize them.

   If this is not valid, then either (i) each dataflash 'priv' structure

   needs it's own transfer descriptor, (ii) we lock this one, or (iii) use

   another mechanism.   */

static struct spi_transfer_list* spi_transfer_desc;



/*

 * Perform a SPI transfer to access the DataFlash device.

 */

static int do_spi_transfer(int nr, char* tx, int tx_len, char* rx, int rx_len,

		char* txnext, int txnext_len, char* rxnext, int rxnext_len)

{

	struct spi_transfer_list* list = spi_transfer_desc;



	list->tx[0] = tx;	list->txlen[0] = tx_len;

	list->rx[0] = rx;	list->rxlen[0] = rx_len;



	list->tx[1] = txnext; 	list->txlen[1] = txnext_len;

	list->rx[1] = rxnext;	list->rxlen[1] = rxnext_len;



	list->nr_transfers = nr;

	/* Note: spi_transfer() always returns 0, there are no error checks */

	return spi_transfer(list);

}



/*

 * Return the status of the DataFlash device.

 */

static unsigned char at91_dataflash26_status(void)

{

	unsigned char command[2];



	command[0] = AT26_OP_READ_STATUS;

	command[1] = 0;



	do_spi_transfer(1, command, 2, command, 2, NULL, 0, NULL, 0);



	return command[1];

}



/*

 * Poll the DataFlash device until it is READY.

 */

static unsigned char at91_dataflash26_waitready(void)

{

	unsigned char status;



	while (1) {

		status = at91_dataflash26_status();

		if (!(status & AT26_STATUS_BUSY))

			return status;

	}

}



/*

 * Enable/disable write access

 */

 static void at91_dataflash26_write_enable(int enable)

{

	unsigned char cmd[2];



	DEBUG(MTD_DEBUG_LEVEL3, "write_enable: enable=%i\n", enable);



	if (enable)

		cmd[0] = AT26_OP_WRITE_ENABLE;

	else

		cmd[0] = AT26_OP_WRITE_DISABLE;

	cmd[1] = 0;



	do_spi_transfer(1, cmd, 2, cmd, 2, NULL, 0, NULL, 0);

}



/*

 * Protect/unprotect sector

 */

 static void at91_dataflash26_sector_protect(loff_t addr, int protect)

{

	unsigned char cmd[4];



	DEBUG(MTD_DEBUG_LEVEL3, "sector_protect: addr=0x%06x prot=%d\n",

	       addr, protect);



	if (protect)

		cmd[0] = AT26_OP_SECTOR_PROTECT;

	else

		cmd[0] = AT26_OP_SECTOR_UNPROTECT;

	cmd[1] = (addr & 0x00FF0000) >> 16;

	cmd[2] = (addr & 0x0000FF00) >> 8;

	cmd[3] = (addr & 0x000000FF);



	do_spi_transfer(1, cmd, 4, cmd, 4, NULL, 0, NULL, 0);

}



/*

 * Erase blocks of flash.

 */

static int at91_dataflash26_erase(struct mtd_info *mtd,

				  struct erase_info *instr)

{

	struct dataflash_local *priv = (struct dataflash_local *) mtd->priv;

	unsigned char cmd[4];



	DEBUG(MTD_DEBUG_LEVEL1, "dataflash_erase: addr=0x%06x len=%i\n",

	       instr->addr, instr->len);



	/* Sanity checks */

	if (priv->page_size != 4096)

		return -EINVAL; /* Can't handle other sizes at the moment */



	if (   ((instr->len % mtd->erasesize) != 0)

	    || ((instr->len % priv->page_size) != 0)

	    || ((instr->addr % priv->page_size) != 0)

	    || ((instr->addr + instr->len) > mtd->size))

		return -EINVAL;



	spi_access_bus(priv->spi);



	while (instr->len > 0) {

		at91_dataflash26_write_enable(1);

		at91_dataflash26_sector_protect(instr->addr, 0);

		at91_dataflash26_write_enable(1);

		cmd[0] = AT26_OP_ERASE_PAGE_4K;

		cmd[1] = (instr->addr & 0x00FF0000) >> 16;

		cmd[2] = (instr->addr & 0x0000FF00) >> 8;

		cmd[3] = (instr->addr & 0x000000FF);



		DEBUG(MTD_DEBUG_LEVEL3, "ERASE: (0x%02x) 0x%02x 0x%02x"

					"0x%02x\n",

			cmd[0], cmd[1], cmd[2], cmd[3]);



		do_spi_transfer(1, cmd, 4, cmd, 4, NULL, 0, NULL, 0);

		at91_dataflash26_waitready();



		instr->addr += priv->page_size;	 /* next page */

		instr->len -= priv->page_size;

	}



	at91_dataflash26_write_enable(0);

	spi_release_bus(priv->spi);



	/* Inform MTD subsystem that erase is complete */

	instr->state = MTD_ERASE_DONE;

	if (instr->callback)

		instr->callback(instr);



	return 0;

}



/*

 * Read from the DataFlash device.

 *   from   : Start offset in flash device

 *   len    : Number of bytes to read

 *   retlen : Number of bytes actually read

 *   buf    : Buffer that will receive data

 */

static int at91_dataflash26_read(struct mtd_info *mtd, loff_t from, size_t len,

				 size_t *retlen, u_char *buf)

{

	struct dataflash_local *priv = (struct dataflash_local *) mtd->priv;

	unsigned char cmd[5];



	DEBUG(MTD_DEBUG_LEVEL1, "dataflash_read: %lli .. %lli\n",

	      from, from+len);



	*retlen = 0;



	/* Sanity checks */

	if (!len)

		return 0;

	if (from + len > mtd->size)

		return -EINVAL;



	cmd[0] = AT26_OP_READ_ARRAY_FAST;

	cmd[1] = (from & 0x00FF0000) >> 16;

	cmd[2] = (from & 0x0000FF00) >> 8;

	cmd[3] = (from & 0x000000FF);

	/* cmd[4] is a "Don't care" byte  */



	DEBUG(MTD_DEBUG_LEVEL3, "READ: (0x%02x) 0x%02x 0x%02x 0x%02x\n",

	       cmd[0], cmd[1], cmd[2], cmd[3]);



	spi_access_bus(priv->spi);

	do_spi_transfer(2, cmd, 5, cmd, 5, buf, len, buf, len);

	spi_release_bus(priv->spi);



	*retlen = len;

	return 0;

}



/*

 * Write to the DataFlash device.

 *   to     : Start offset in flash device

 *   len    : Number of bytes to write

 *   retlen : Number of bytes actually written

 *   buf    : Buffer containing the data

 */

static int at91_dataflash26_write(struct mtd_info *mtd, loff_t to, size_t len,

				  size_t *retlen, const u_char *buf)

{

	struct dataflash_local *priv = (struct dataflash_local *) mtd->priv;

	unsigned int addr, buf_index = 0;

	int ret = -EIO, sector, last_sector;

	unsigned char status, cmd[5];



	DEBUG(MTD_DEBUG_LEVEL1, "dataflash_write: %lli .. %lli\n", to, to+len);



	*retlen = 0;



	/* Sanity checks */

	if (!len)

		return 0;

	if (to + len > mtd->size)

		return -EINVAL;



	spi_access_bus(priv->spi);



	addr = to;

	last_sector = -1;



	while (buf_index < len) {

		sector = addr / priv->page_size;

		/* Write first byte if a new sector begins */

		if (sector != last_sector) {

			at91_dataflash26_write_enable(1);

			at91_dataflash26_sector_protect(addr, 0);

			at91_dataflash26_write_enable(1);



			/* Program first byte of a new sector */

			cmd[0] = AT26_OP_SEQUENTIAL_WRITE;

			cmd[1] = (addr & 0x00FF0000) >> 16;

			cmd[2] = (addr & 0x0000FF00) >> 8;

			cmd[3] = (addr & 0x000000FF);

			cmd[4] = buf[buf_index++];

			do_spi_transfer(1, cmd, 5, cmd, 5, NULL, 0, NULL, 0);

			status = at91_dataflash26_waitready();

			addr++;

			/* On write errors, the chip resets the write enable

			   flag. This also happens after the last byte of a

			   sector is successfully programmed. */

			if (   ( !(status & AT26_STATUS_WRITE_ENABLE))

			    && ((addr % priv->page_size) != 0) ) {

				DEBUG(MTD_DEBUG_LEVEL1,

					"write error1: addr=0x%06x, "

					"status=0x%02x\n", addr, status);

				goto write_err;

			}

			(*retlen)++;

			last_sector = sector;

		}



		/* Write subsequent bytes in the same sector */

		cmd[0] = AT26_OP_SEQUENTIAL_WRITE;

		cmd[1] = buf[buf_index++];

		do_spi_transfer(1, cmd, 2, cmd, 2, NULL, 0, NULL, 0);

		status = at91_dataflash26_waitready();

		addr++;



		if (   ( !(status & AT26_STATUS_WRITE_ENABLE))

		    && ((addr % priv->page_size) != 0) ) {

			DEBUG(MTD_DEBUG_LEVEL1, "write error2: addr=0x%06x, "

				"status=0x%02x\n", addr, status);

			goto write_err;

		}



		(*retlen)++;

	}



	ret = 0;

	at91_dataflash26_write_enable(0);

write_err:

	spi_release_bus(priv->spi);

	return ret;

}



/*

 * Initialize and register DataFlash device with MTD subsystem.

 */

static int __init add_dataflash(int channel, char *name, int nr_pages,

				int pagesize)

{

	struct mtd_info *device;

	struct dataflash_local *priv;



	if (nr_devices >= DATAFLASH_MAX_DEVICES) {

		printk(KERN_ERR "at91_dataflash26: Too many devices "

				"detected\n");

		return 0;

	}



	device = kzalloc(sizeof(struct mtd_info) + strlen(name) + 8,

			 GFP_KERNEL);

	if (!device)

		return -ENOMEM;



	device->name = (char *)&device[1];

	sprintf(device->name, "%s.spi%d", name, channel);

	device->size = nr_pages * pagesize;

	device->erasesize = pagesize;

	device->owner = THIS_MODULE;

	device->type = MTD_DATAFLASH;

	device->flags = MTD_CAP_NORFLASH;

	device->erase = at91_dataflash26_erase;

	device->read = at91_dataflash26_read;

	device->write = at91_dataflash26_write;



	priv = (struct dataflash_local *)kzalloc(sizeof(struct dataflash_local),

		GFP_KERNEL);

	if (!priv) {

		kfree(device);

		return -ENOMEM;

	}



	priv->spi = channel;

	priv->page_size = pagesize;

	device->priv = priv;



	mtd_devices[nr_devices] = device;

	nr_devices++;

	printk(KERN_INFO "at91_dataflash26: %s detected [spi%i] (%i bytes)\n",

	       name, channel, device->size);



	return add_mtd_device(device);

}



/*

 * Detect and initialize DataFlash device connected to specified SPI channel.

 *

 */



struct dataflash26_types {

	unsigned char id0;

	unsigned char id1;

	char *name;

	int pagesize;

	int nr_pages;

};



struct dataflash26_types df26_types[] = {

	{

		.id0 = 0x04,

		.id1 = 0x00,

		.name = "AT26F004",

		.pagesize = 4096,

		.nr_pages = 128,

	},

	{

		.id0 = 0x45,

		.id1 = 0x01,

		.name = "AT26DF081A", /* Not tested ! */

		.pagesize = 4096,

		.nr_pages = 256,

	},

};



static int __init at91_dataflash26_detect(int channel)

{

	unsigned char status, cmd[5];

	int i;



	spi_access_bus(channel);

	status = at91_dataflash26_status();



	if (status == 0 || status == 0xff) {

		printk(KERN_ERR "at91_dataflash26_detect: status error %d\n",

			status);

		spi_release_bus(channel);

		return -ENODEV;

	}



	cmd[0] = AT26_OP_READ_DEV_ID;

	do_spi_transfer(1, cmd, 5, cmd, 5, NULL, 0, NULL, 0);

	spi_release_bus(channel);



	if (cmd[1] != MANUFACTURER_ID_ATMEL)

		return -ENODEV;



	for (i = 0; i < ARRAY_SIZE(df26_types); i++) {

		if (   cmd[2] == df26_types[i].id0

		    && cmd[3] == df26_types[i].id1)

			return add_dataflash(channel,

						df26_types[i].name,

						df26_types[i].nr_pages,

						df26_types[i].pagesize);

	}



	printk(KERN_ERR "at91_dataflash26_detect: Unsupported device "

			"(0x%02x/0x%02x)\n", cmd[2], cmd[3]);

	return -ENODEV;

}



static int __init at91_dataflash26_init(void)

{

	spi_transfer_desc = kmalloc(sizeof(struct spi_transfer_list),

				    GFP_KERNEL);

	if (!spi_transfer_desc)

		return -ENOMEM;



	/* DataFlash (SPI chip select 0) */

	at91_dataflash26_detect(0);



#ifdef CONFIG_MTD_AT91_DATAFLASH_CARD

	/* DataFlash card (SPI chip select 3) */

	at91_dataflash26_detect(3);

#endif

	return 0;

}



static void __exit at91_dataflash26_exit(void)

{

	int i;



	for (i = 0; i < DATAFLASH_MAX_DEVICES; i++) {

		if (mtd_devices[i]) {

			del_mtd_device(mtd_devices[i]);

			kfree(mtd_devices[i]->priv);

			kfree(mtd_devices[i]);

		}

	}

	nr_devices = 0;

	kfree(spi_transfer_desc);

}



module_init(at91_dataflash26_init);

module_exit(at91_dataflash26_exit);



MODULE_LICENSE("GPL");

MODULE_AUTHOR("Hans J. Koch");

MODULE_DESCRIPTION("DataFlash AT26xxx driver for Atmel AT91RM9200");

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