--- /dev/null
+/*
+ * 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/err.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/slab.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 <linux/of.h>
+
+#include <lantiq_soc.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 const char ltq_map_name[] = "ltq_nor";
+static const char * const ltq_probe_types[] = { "cmdlinepart", "ofpart", 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
+ltq_mtd_probe(struct platform_device *pdev)
+{
+ struct mtd_part_parser_data ppdata;
+ struct ltq_mtd *ltq_mtd;
+ struct cfi_private *cfi;
+ int err;
+
+ if (of_machine_is_compatible("lantiq,falcon") &&
+ (ltq_boot_select() != BS_FLASH)) {
+ dev_err(&pdev->dev, "invalid bootstrap options\n");
+ return -ENODEV;
+ }
+
+ ltq_mtd = devm_kzalloc(&pdev->dev, sizeof(struct ltq_mtd), GFP_KERNEL);
+ if (!ltq_mtd)
+ return -ENOMEM;
+
+ 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\n");
+ return -ENOENT;
+ }
+
+ ltq_mtd->map = devm_kzalloc(&pdev->dev, sizeof(struct map_info),
+ GFP_KERNEL);
+ if (!ltq_mtd->map)
+ return -ENOMEM;
+
+ ltq_mtd->map->phys = ltq_mtd->res->start;
+ ltq_mtd->map->size = resource_size(ltq_mtd->res);
+ ltq_mtd->map->virt = devm_ioremap_resource(&pdev->dev, ltq_mtd->res);
+ if (IS_ERR(ltq_mtd->map->virt))
+ return PTR_ERR(ltq_mtd->map->virt);
+
+ 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");
+ return -ENXIO;
+ }
+
+ ltq_mtd->mtd->owner = THIS_MODULE;
+
+ cfi = ltq_mtd->map->fldrv_priv;
+ cfi->addr_unlock1 ^= 1;
+ cfi->addr_unlock2 ^= 1;
+
+ ppdata.of_node = pdev->dev.of_node;
+ err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types,
+ &ppdata, NULL, 0);
+ if (err) {
+ dev_err(&pdev->dev, "failed to add partitions\n");
+ goto err_destroy;
+ }
+
+ return 0;
+
+err_destroy:
+ map_destroy(ltq_mtd->mtd);
+ return err;
+}
+
+static int
+ltq_mtd_remove(struct platform_device *pdev)
+{
+ struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
+
+ if (ltq_mtd && ltq_mtd->mtd) {
+ mtd_device_unregister(ltq_mtd->mtd);
+ map_destroy(ltq_mtd->mtd);
+ }
+ return 0;
+}
+
+static const struct of_device_id ltq_mtd_match[] = {
+ { .compatible = "lantiq,nor" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ltq_mtd_match);
+
+static struct platform_driver ltq_mtd_driver = {
+ .probe = ltq_mtd_probe,
+ .remove = ltq_mtd_remove,
+ .driver = {
+ .name = "ltq-nor",
+ .of_match_table = ltq_mtd_match,
+ },
+};
+
+module_platform_driver(ltq_mtd_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
+MODULE_DESCRIPTION("Lantiq SoC NOR");
Code Review / kvmfornfv.git / blobdiff