Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 207 insertions, 0 deletions

diff --git a/drivers/mtd/maps/lantiq-flash.c b/drivers/mtd/maps/lantiq-flash.c
new file mode 100644
index 000000000..77b1d8013
--- /dev/null
+++ b/drivers/mtd/maps/lantiq-flash.c
@@ -0,0 +1,207 @@
+/*
+ *  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 <john@phrozen.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 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 ltq_mtd *ltq_mtd;
+	struct cfi_private *cfi;
+	int err;
+
+	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->dev.parent = &pdev->dev;
+	mtd_set_of_node(ltq_mtd->mtd, pdev->dev.of_node);
+
+	cfi = ltq_mtd->map->fldrv_priv;
+	cfi->addr_unlock1 ^= 1;
+	cfi->addr_unlock2 ^= 1;
+
+	err = mtd_device_register(ltq_mtd->mtd, 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 <john@phrozen.org>");
+MODULE_DESCRIPTION("Lantiq SoC NOR");