- 根目录:
- drivers
- mtd
- maps
- ixp4xx.c
/*
* drivers/mtd/maps/ixp4xx.c
*
* MTD Map file for IXP4XX based systems. Please do not make per-board
* changes in here. If your board needs special setup, do it in your
* platform level code in arch/arm/mach-ixp4xx/board-setup.c
*
* Original Author: Intel Corporation
* Maintainer: Deepak Saxena <dsaxena@mvista.com>
*
* Copyright (C) 2002 Intel Corporation
* Copyright (C) 2003-2004 MontaVista Software, Inc.
*
*/
#include <linux/err.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <asm/io.h>
#include <asm/mach/flash.h>
#include <linux/reboot.h>
/*
* Read/write a 16 bit word from flash address 'addr'.
*
* When the cpu is in little-endian mode it swizzles the address lines
* ('address coherency') so we need to undo the swizzling to ensure commands
* and the like end up on the correct flash address.
*
* To further complicate matters, due to the way the expansion bus controller
* handles 32 bit reads, the byte stream ABCD is stored on the flash as:
* D15 D0
* +---+---+
* | A | B | 0
* +---+---+
* | C | D | 2
* +---+---+
* This means that on LE systems each 16 bit word must be swapped. Note that
* this requires CONFIG_MTD_CFI_BE_BYTE_SWAP to be enabled to 'unswap' the CFI
* data and other flash commands which are always in D7-D0.
*/
#ifndef __ARMEB__
#ifndef CONFIG_MTD_CFI_BE_BYTE_SWAP
# error CONFIG_MTD_CFI_BE_BYTE_SWAP required
#endif
static inline u16 flash_read16(void __iomem *addr)
{
return be16_to_cpu(__raw_readw((void __iomem *)((unsigned long)addr ^ 0x2)));
}
static inline void flash_write16(u16 d, void __iomem *addr)
{
__raw_writew(cpu_to_be16(d), (void __iomem *)((unsigned long)addr ^ 0x2));
}
#define BYTE0(h) ((h) & 0xFF)
#define BYTE1(h) (((h) >> 8) & 0xFF)
#else
static inline u16 flash_read16(const void __iomem *addr)
{
return __raw_readw(addr);
}
static inline void flash_write16(u16 d, void __iomem *addr)
{
__raw_writew(d, addr);
}
#define BYTE0(h) (((h) >> 8) & 0xFF)
#define BYTE1(h) ((h) & 0xFF)
#endif
static map_word ixp4xx_read16(struct map_info *map, unsigned long ofs)
{
map_word val;
val.x[0] = flash_read16(map->virt + ofs);
return val;
}
/*
* The IXP4xx expansion bus only allows 16-bit wide acceses
* when attached to a 16-bit wide device (such as the 28F128J3A),
* so we can't just memcpy_fromio().
*/
static void ixp4xx_copy_from(struct map_info *map, void *to,
unsigned long from, ssize_t len)
{
u8 *dest = (u8 *) to;
void __iomem *src = map->virt + from;
if (len <= 0)
return;
if (from & 1) {
*dest++ = BYTE1(flash_read16(src-1));
src++;
--len;
}
while (len >= 2) {
u16 data = flash_read16(src);
*dest++ = BYTE0(data);
*dest++ = BYTE1(data);
src += 2;
len -= 2;
}
if (len > 0)
*dest++ = BYTE0(flash_read16(src));
}
/*
* Unaligned writes are ignored, causing the 8-bit
* probe to fail and proceed to the 16-bit probe (which succeeds).
*/
static void ixp4xx_probe_write16(struct map_info *map, map_word d, unsigned long adr)
{
if (!(adr & 1))
flash_write16(d.x[0], map->virt + adr);
}
/*
* Fast write16 function without the probing check above
*/
static void ixp4xx_write16(struct map_info *map, map_word d, unsigned long adr)
{
flash_write16(d.x[0], map->virt + adr);
}
struct ixp4xx_flash_info {
struct mtd_info *mtd;
struct map_info map;
struct resource *res;
};
static const char * const probes[] = { "RedBoot", "cmdlinepart", NULL };
static int ixp4xx_flash_remove(struct platform_device *dev)
{
struct flash_platform_data *plat = dev_get_platdata(&dev->dev);
struct ixp4xx_flash_info *info = platform_get_drvdata(dev);
if(!info)
return 0;
if (info->mtd) {
mtd_device_unregister(info->mtd);
map_destroy(info->mtd);
}
if (plat->exit)
plat->exit();
return 0;
}
static int ixp4xx_flash_probe(struct platform_device *dev)
{
struct flash_platform_data *plat = dev_get_platdata(&dev->dev);
struct ixp4xx_flash_info *info;
struct mtd_part_parser_data ppdata = {
.origin = dev->resource->start,
};
int err = -1;
if (!plat)
return -ENODEV;
if (plat->init) {
err = plat->init();
if (err)
return err;
}
info = devm_kzalloc(&dev->dev, sizeof(struct ixp4xx_flash_info),
GFP_KERNEL);
if(!info) {
err = -ENOMEM;
goto Error;
}
platform_set_drvdata(dev, info);
/*
* Tell the MTD layer we're not 1:1 mapped so that it does
* not attempt to do a direct access on us.
*/
info->map.phys = NO_XIP;
info->map.size = resource_size(dev->resource);
/*
* We only support 16-bit accesses for now. If and when
* any board use 8-bit access, we'll fixup the driver to
* handle that.
*/
info->map.bankwidth = 2;
info->map.name = dev_name(&dev->dev);
info->map.read = ixp4xx_read16;
info->map.write = ixp4xx_probe_write16;
info->map.copy_from = ixp4xx_copy_from;
info->map.virt = devm_ioremap_resource(&dev->dev, dev->resource);
if (IS_ERR(info->map.virt)) {
err = PTR_ERR(info->map.virt);
goto Error;
}
info->mtd = do_map_probe(plat->map_name, &info->map);
if (!info->mtd) {
printk(KERN_ERR "IXP4XXFlash: map_probe failed\n");
err = -ENXIO;
goto Error;
}
info->mtd->owner = THIS_MODULE;
/* Use the fast version */
info->map.write = ixp4xx_write16;
err = mtd_device_parse_register(info->mtd, probes, &ppdata,
plat->parts, plat->nr_parts);
if (err) {
printk(KERN_ERR "Could not parse partitions\n");
goto Error;
}
return 0;
Error:
ixp4xx_flash_remove(dev);
return err;
}
static struct platform_driver ixp4xx_flash_driver = {
.probe = ixp4xx_flash_probe,
.remove = ixp4xx_flash_remove,
.driver = {
.name = "IXP4XX-Flash",
.owner = THIS_MODULE,
},
};
module_platform_driver(ixp4xx_flash_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MTD map driver for Intel IXP4xx systems");
MODULE_AUTHOR("Deepak Saxena");
MODULE_ALIAS("platform:IXP4XX-Flash");