/* * 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. * * Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE * Copyright (C) 2010 John Crispin <blogic@openwrt.org> */ #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/io.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/mtd/mtd.h> #include <linux/mtd/map.h> #include <linux/mtd/partitions.h> #include <linux/mtd/cfi.h> #include <linux/platform_device.h> #include <linux/mtd/physmap.h> #include <lantiq_soc.h> #include <lantiq_platform.h> /* * The NOR flash is connected to the same external bus unit (EBU) as PCI. * To make PCI work we need to enable the endianness swapping for the address * written to the EBU. This endianness swapping works for PCI correctly but * fails for attached NOR devices. To workaround this we need to use a complex * map. The workaround involves swapping all addresses whilst probing the chip. * Once probing is complete we stop swapping the addresses but swizzle the * unlock addresses to ensure that access to the NOR device works correctly. */ enum { LTQ_NOR_PROBING, LTQ_NOR_NORMAL }; struct ltq_mtd { struct resource *res; struct mtd_info *mtd; struct map_info *map; }; static char ltq_map_name[] = "ltq_nor"; static const char *ltq_probe_types[] __devinitconst = { "cmdlinepart", NULL }; static map_word ltq_read16(struct map_info *map, unsigned long adr) { unsigned long flags; map_word temp; if (map->map_priv_1 == LTQ_NOR_PROBING) adr ^= 2; spin_lock_irqsave(&ebu_lock, flags); temp.x[0] = *(u16 *)(map->virt + adr); spin_unlock_irqrestore(&ebu_lock, flags); return temp; } static void ltq_write16(struct map_info *map, map_word d, unsigned long adr) { unsigned long flags; if (map->map_priv_1 == LTQ_NOR_PROBING) adr ^= 2; spin_lock_irqsave(&ebu_lock, flags); *(u16 *)(map->virt + adr) = d.x[0]; spin_unlock_irqrestore(&ebu_lock, flags); } /* * The following 2 functions copy data between iomem and a cached memory * section. As memcpy() makes use of pre-fetching we cannot use it here. * The normal alternative of using memcpy_{to,from}io also makes use of * memcpy() on MIPS so it is not applicable either. We are therefore stuck * with having to use our own loop. */ static void ltq_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len) { unsigned char *f = (unsigned char *)map->virt + from; unsigned char *t = (unsigned char *)to; unsigned long flags; spin_lock_irqsave(&ebu_lock, flags); while (len--) *t++ = *f++; spin_unlock_irqrestore(&ebu_lock, flags); } static void ltq_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len) { unsigned char *f = (unsigned char *)from; unsigned char *t = (unsigned char *)map->virt + to; unsigned long flags; spin_lock_irqsave(&ebu_lock, flags); while (len--) *t++ = *f++; spin_unlock_irqrestore(&ebu_lock, flags); } static int __init ltq_mtd_probe(struct platform_device *pdev) { struct physmap_flash_data *ltq_mtd_data = dev_get_platdata(&pdev->dev); struct ltq_mtd *ltq_mtd; struct resource *res; struct cfi_private *cfi; int err; ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL); platform_set_drvdata(pdev, ltq_mtd); ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!ltq_mtd->res) { dev_err(&pdev->dev, "failed to get memory resource"); err = -ENOENT; goto err_out; } res = devm_request_mem_region(&pdev->dev, ltq_mtd->res->start, resource_size(ltq_mtd->res), dev_name(&pdev->dev)); if (!ltq_mtd->res) { dev_err(&pdev->dev, "failed to request mem resource"); err = -EBUSY; goto err_out; } ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL); ltq_mtd->map->phys = res->start; ltq_mtd->map->size = resource_size(res); ltq_mtd->map->virt = devm_ioremap_nocache(&pdev->dev, ltq_mtd->map->phys, ltq_mtd->map->size); if (!ltq_mtd->map->virt) { dev_err(&pdev->dev, "failed to ioremap!\n"); err = -ENOMEM; goto err_free; } ltq_mtd->map->name = ltq_map_name; ltq_mtd->map->bankwidth = 2; ltq_mtd->map->read = ltq_read16; ltq_mtd->map->write = ltq_write16; ltq_mtd->map->copy_from = ltq_copy_from; ltq_mtd->map->copy_to = ltq_copy_to; ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING; ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map); ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL; if (!ltq_mtd->mtd) { dev_err(&pdev->dev, "probing failed\n"); err = -ENXIO; goto err_free; } ltq_mtd->mtd->owner = THIS_MODULE; cfi = ltq_mtd->map->fldrv_priv; cfi->addr_unlock1 ^= 1; cfi->addr_unlock2 ^= 1; err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types, NULL, ltq_mtd_data->parts, ltq_mtd_data->nr_parts); if (err) { dev_err(&pdev->dev, "failed to add partitions\n"); goto err_destroy; } return 0; err_destroy: map_destroy(ltq_mtd->mtd); err_free: kfree(ltq_mtd->map); err_out: kfree(ltq_mtd); return err; } static int __devexit ltq_mtd_remove(struct platform_device *pdev) { struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev); if (ltq_mtd) { if (ltq_mtd->mtd) { mtd_device_unregister(ltq_mtd->mtd); map_destroy(ltq_mtd->mtd); } kfree(ltq_mtd->map); kfree(ltq_mtd); } return 0; } static struct platform_driver ltq_mtd_driver = { .remove = __devexit_p(ltq_mtd_remove), .driver = { .name = "ltq_nor", .owner = THIS_MODULE, }, }; static int __init init_ltq_mtd(void) { int ret = platform_driver_probe(<q_mtd_driver, ltq_mtd_probe); if (ret) pr_err("ltq_nor: error registering platform driver"); return ret; } static void __exit exit_ltq_mtd(void) { platform_driver_unregister(<q_mtd_driver); } module_init(init_ltq_mtd); module_exit(exit_ltq_mtd); MODULE_LICENSE("GPL"); MODULE_AUTHOR("John Crispin <blogic@openwrt.org>"); MODULE_DESCRIPTION("Lantiq SoC NOR");