From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Thu, 11 Apr 2024 10:27:49 +0200
Subject: Adding upstream version 6.6.15.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 drivers/mtd/chips/map_rom.c | 133 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 133 insertions(+)
 create mode 100644 drivers/mtd/chips/map_rom.c

(limited to 'drivers/mtd/chips/map_rom.c')

diff --git a/drivers/mtd/chips/map_rom.c b/drivers/mtd/chips/map_rom.c
new file mode 100644
index 0000000000..0823b15aaa
--- /dev/null
+++ b/drivers/mtd/chips/map_rom.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common code to handle map devices which are simple ROM
+ * (C) 2000 Red Hat.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <asm/io.h>
+#include <asm/byteorder.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+
+static int maprom_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
+static int maprom_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
+static void maprom_nop (struct mtd_info *);
+static struct mtd_info *map_rom_probe(struct map_info *map);
+static int maprom_erase (struct mtd_info *mtd, struct erase_info *info);
+static int maprom_point (struct mtd_info *mtd, loff_t from, size_t len,
+			 size_t *retlen, void **virt, resource_size_t *phys);
+static int maprom_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
+
+
+static struct mtd_chip_driver maprom_chipdrv = {
+	.probe	= map_rom_probe,
+	.name	= "map_rom",
+	.module	= THIS_MODULE
+};
+
+static unsigned int default_erasesize(struct map_info *map)
+{
+	const __be32 *erase_size = NULL;
+
+	erase_size = of_get_property(map->device_node, "erase-size", NULL);
+
+	return !erase_size ? map->size : be32_to_cpu(*erase_size);
+}
+
+static struct mtd_info *map_rom_probe(struct map_info *map)
+{
+	struct mtd_info *mtd;
+
+	mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
+	if (!mtd)
+		return NULL;
+
+	map->fldrv = &maprom_chipdrv;
+	mtd->priv = map;
+	mtd->name = map->name;
+	mtd->type = MTD_ROM;
+	mtd->size = map->size;
+	mtd->_point = maprom_point;
+	mtd->_unpoint = maprom_unpoint;
+	mtd->_read = maprom_read;
+	mtd->_write = maprom_write;
+	mtd->_sync = maprom_nop;
+	mtd->_erase = maprom_erase;
+	mtd->flags = MTD_CAP_ROM;
+	mtd->erasesize = default_erasesize(map);
+	mtd->writesize = 1;
+	mtd->writebufsize = 1;
+
+	__module_get(THIS_MODULE);
+	return mtd;
+}
+
+
+static int maprom_point(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, void **virt, resource_size_t *phys)
+{
+	struct map_info *map = mtd->priv;
+
+	if (!map->virt)
+		return -EINVAL;
+	*virt = map->virt + from;
+	if (phys)
+		*phys = map->phys + from;
+	*retlen = len;
+	return 0;
+}
+
+static int maprom_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+	return 0;
+}
+
+static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
+{
+	struct map_info *map = mtd->priv;
+
+	map_copy_from(map, buf, from, len);
+	*retlen = len;
+	return 0;
+}
+
+static void maprom_nop(struct mtd_info *mtd)
+{
+	/* Nothing to see here */
+}
+
+static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
+{
+	return -EROFS;
+}
+
+static int maprom_erase (struct mtd_info *mtd, struct erase_info *info)
+{
+	/* We do our best 8) */
+	return -EROFS;
+}
+
+static int __init map_rom_init(void)
+{
+	register_mtd_chip_driver(&maprom_chipdrv);
+	return 0;
+}
+
+static void __exit map_rom_exit(void)
+{
+	unregister_mtd_chip_driver(&maprom_chipdrv);
+}
+
+module_init(map_rom_init);
+module_exit(map_rom_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("MTD chip driver for ROM chips");
-- 
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