diff options
Diffstat (limited to 'drivers/mtd/maps/ixp4xx.c')
| -rw-r--r-- | drivers/mtd/maps/ixp4xx.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/mtd/maps/ixp4xx.c b/drivers/mtd/maps/ixp4xx.c new file mode 100644 index 000000000..d8543201a --- /dev/null +++ b/drivers/mtd/maps/ixp4xx.c @@ -0,0 +1,262 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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/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->dev.parent = &dev->dev; + + /* 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", + }, +}; + +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"); |