mirror of https://gitee.com/openkylin/linux.git
206 lines
5.0 KiB
C
206 lines
5.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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*
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* Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE
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* Copyright (C) 2010 John Crispin <john@phrozen.org>
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*/
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/map.h>
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#include <linux/mtd/partitions.h>
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#include <linux/mtd/cfi.h>
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#include <linux/platform_device.h>
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#include <linux/mtd/physmap.h>
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#include <linux/of.h>
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#include <lantiq_soc.h>
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/*
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* The NOR flash is connected to the same external bus unit (EBU) as PCI.
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* To make PCI work we need to enable the endianness swapping for the address
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* written to the EBU. This endianness swapping works for PCI correctly but
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* fails for attached NOR devices. To workaround this we need to use a complex
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* map. The workaround involves swapping all addresses whilst probing the chip.
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* Once probing is complete we stop swapping the addresses but swizzle the
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* unlock addresses to ensure that access to the NOR device works correctly.
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*/
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enum {
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LTQ_NOR_PROBING,
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LTQ_NOR_NORMAL
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};
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struct ltq_mtd {
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struct resource *res;
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struct mtd_info *mtd;
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struct map_info *map;
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};
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static const char ltq_map_name[] = "ltq_nor";
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static map_word
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ltq_read16(struct map_info *map, unsigned long adr)
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{
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unsigned long flags;
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map_word temp;
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if (map->map_priv_1 == LTQ_NOR_PROBING)
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adr ^= 2;
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spin_lock_irqsave(&ebu_lock, flags);
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temp.x[0] = *(u16 *)(map->virt + adr);
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spin_unlock_irqrestore(&ebu_lock, flags);
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return temp;
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}
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static void
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ltq_write16(struct map_info *map, map_word d, unsigned long adr)
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{
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unsigned long flags;
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if (map->map_priv_1 == LTQ_NOR_PROBING)
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adr ^= 2;
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spin_lock_irqsave(&ebu_lock, flags);
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*(u16 *)(map->virt + adr) = d.x[0];
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spin_unlock_irqrestore(&ebu_lock, flags);
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}
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/*
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* The following 2 functions copy data between iomem and a cached memory
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* section. As memcpy() makes use of pre-fetching we cannot use it here.
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* The normal alternative of using memcpy_{to,from}io also makes use of
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* memcpy() on MIPS so it is not applicable either. We are therefore stuck
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* with having to use our own loop.
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*/
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static void
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ltq_copy_from(struct map_info *map, void *to,
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unsigned long from, ssize_t len)
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{
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unsigned char *f = (unsigned char *)map->virt + from;
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unsigned char *t = (unsigned char *)to;
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unsigned long flags;
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spin_lock_irqsave(&ebu_lock, flags);
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while (len--)
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*t++ = *f++;
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spin_unlock_irqrestore(&ebu_lock, flags);
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}
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static void
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ltq_copy_to(struct map_info *map, unsigned long to,
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const void *from, ssize_t len)
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{
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unsigned char *f = (unsigned char *)from;
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unsigned char *t = (unsigned char *)map->virt + to;
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unsigned long flags;
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spin_lock_irqsave(&ebu_lock, flags);
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while (len--)
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*t++ = *f++;
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spin_unlock_irqrestore(&ebu_lock, flags);
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}
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static int
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ltq_mtd_probe(struct platform_device *pdev)
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{
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struct ltq_mtd *ltq_mtd;
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struct cfi_private *cfi;
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int err;
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ltq_mtd = devm_kzalloc(&pdev->dev, sizeof(struct ltq_mtd), GFP_KERNEL);
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if (!ltq_mtd)
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return -ENOMEM;
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platform_set_drvdata(pdev, ltq_mtd);
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ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!ltq_mtd->res) {
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dev_err(&pdev->dev, "failed to get memory resource\n");
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return -ENOENT;
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}
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ltq_mtd->map = devm_kzalloc(&pdev->dev, sizeof(struct map_info),
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GFP_KERNEL);
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if (!ltq_mtd->map)
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return -ENOMEM;
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ltq_mtd->map->phys = ltq_mtd->res->start;
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ltq_mtd->map->size = resource_size(ltq_mtd->res);
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ltq_mtd->map->virt = devm_ioremap_resource(&pdev->dev, ltq_mtd->res);
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if (IS_ERR(ltq_mtd->map->virt))
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return PTR_ERR(ltq_mtd->map->virt);
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ltq_mtd->map->name = ltq_map_name;
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ltq_mtd->map->bankwidth = 2;
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ltq_mtd->map->read = ltq_read16;
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ltq_mtd->map->write = ltq_write16;
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ltq_mtd->map->copy_from = ltq_copy_from;
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ltq_mtd->map->copy_to = ltq_copy_to;
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ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
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ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
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ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
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if (!ltq_mtd->mtd) {
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dev_err(&pdev->dev, "probing failed\n");
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return -ENXIO;
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}
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ltq_mtd->mtd->dev.parent = &pdev->dev;
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mtd_set_of_node(ltq_mtd->mtd, pdev->dev.of_node);
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cfi = ltq_mtd->map->fldrv_priv;
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cfi->addr_unlock1 ^= 1;
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cfi->addr_unlock2 ^= 1;
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err = mtd_device_register(ltq_mtd->mtd, NULL, 0);
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if (err) {
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dev_err(&pdev->dev, "failed to add partitions\n");
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goto err_destroy;
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}
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return 0;
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err_destroy:
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map_destroy(ltq_mtd->mtd);
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return err;
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}
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static int
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ltq_mtd_remove(struct platform_device *pdev)
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{
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struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
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if (ltq_mtd && ltq_mtd->mtd) {
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mtd_device_unregister(ltq_mtd->mtd);
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map_destroy(ltq_mtd->mtd);
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}
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return 0;
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}
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static const struct of_device_id ltq_mtd_match[] = {
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{ .compatible = "lantiq,nor" },
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{},
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};
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MODULE_DEVICE_TABLE(of, ltq_mtd_match);
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static struct platform_driver ltq_mtd_driver = {
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.probe = ltq_mtd_probe,
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.remove = ltq_mtd_remove,
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.driver = {
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.name = "ltq-nor",
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.of_match_table = ltq_mtd_match,
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},
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};
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module_platform_driver(ltq_mtd_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("John Crispin <john@phrozen.org>");
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MODULE_DESCRIPTION("Lantiq SoC NOR");
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