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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/mtd/chips/map_ram.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/mtd/chips/map_ram.c')
-rw-r--r--kernel/drivers/mtd/chips/map_ram.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/kernel/drivers/mtd/chips/map_ram.c b/kernel/drivers/mtd/chips/map_ram.c
new file mode 100644
index 000000000..afb43d5e1
--- /dev/null
+++ b/kernel/drivers/mtd/chips/map_ram.c
@@ -0,0 +1,154 @@
+/*
+ * Common code to handle map devices which are simple RAM
+ * (C) 2000 Red Hat. GPL'd.
+ */
+
+#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/mtd/mtd.h>
+#include <linux/mtd/map.h>
+
+
+static int mapram_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
+static int mapram_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
+static int mapram_erase (struct mtd_info *, struct erase_info *);
+static void mapram_nop (struct mtd_info *);
+static struct mtd_info *map_ram_probe(struct map_info *map);
+static unsigned long mapram_unmapped_area(struct mtd_info *, unsigned long,
+ unsigned long, unsigned long);
+
+
+static struct mtd_chip_driver mapram_chipdrv = {
+ .probe = map_ram_probe,
+ .name = "map_ram",
+ .module = THIS_MODULE
+};
+
+static struct mtd_info *map_ram_probe(struct map_info *map)
+{
+ struct mtd_info *mtd;
+
+ /* Check the first byte is RAM */
+#if 0
+ map_write8(map, 0x55, 0);
+ if (map_read8(map, 0) != 0x55)
+ return NULL;
+
+ map_write8(map, 0xAA, 0);
+ if (map_read8(map, 0) != 0xAA)
+ return NULL;
+
+ /* Check the last byte is RAM */
+ map_write8(map, 0x55, map->size-1);
+ if (map_read8(map, map->size-1) != 0x55)
+ return NULL;
+
+ map_write8(map, 0xAA, map->size-1);
+ if (map_read8(map, map->size-1) != 0xAA)
+ return NULL;
+#endif
+ /* OK. It seems to be RAM. */
+
+ mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
+ if (!mtd)
+ return NULL;
+
+ map->fldrv = &mapram_chipdrv;
+ mtd->priv = map;
+ mtd->name = map->name;
+ mtd->type = MTD_RAM;
+ mtd->size = map->size;
+ mtd->_erase = mapram_erase;
+ mtd->_get_unmapped_area = mapram_unmapped_area;
+ mtd->_read = mapram_read;
+ mtd->_write = mapram_write;
+ mtd->_panic_write = mapram_write;
+ mtd->_sync = mapram_nop;
+ mtd->flags = MTD_CAP_RAM;
+ mtd->writesize = 1;
+
+ mtd->erasesize = PAGE_SIZE;
+ while(mtd->size & (mtd->erasesize - 1))
+ mtd->erasesize >>= 1;
+
+ __module_get(THIS_MODULE);
+ return mtd;
+}
+
+
+/*
+ * Allow NOMMU mmap() to directly map the device (if not NULL)
+ * - return the address to which the offset maps
+ * - return -ENOSYS to indicate refusal to do the mapping
+ */
+static unsigned long mapram_unmapped_area(struct mtd_info *mtd,
+ unsigned long len,
+ unsigned long offset,
+ unsigned long flags)
+{
+ struct map_info *map = mtd->priv;
+ return (unsigned long) map->virt + offset;
+}
+
+static int mapram_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 int mapram_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
+{
+ struct map_info *map = mtd->priv;
+
+ map_copy_to(map, to, buf, len);
+ *retlen = len;
+ return 0;
+}
+
+static int mapram_erase (struct mtd_info *mtd, struct erase_info *instr)
+{
+ /* Yeah, it's inefficient. Who cares? It's faster than a _real_
+ flash erase. */
+ struct map_info *map = mtd->priv;
+ map_word allff;
+ unsigned long i;
+
+ allff = map_word_ff(map);
+ for (i=0; i<instr->len; i += map_bankwidth(map))
+ map_write(map, allff, instr->addr + i);
+ instr->state = MTD_ERASE_DONE;
+ mtd_erase_callback(instr);
+ return 0;
+}
+
+static void mapram_nop(struct mtd_info *mtd)
+{
+ /* Nothing to see here */
+}
+
+static int __init map_ram_init(void)
+{
+ register_mtd_chip_driver(&mapram_chipdrv);
+ return 0;
+}
+
+static void __exit map_ram_exit(void)
+{
+ unregister_mtd_chip_driver(&mapram_chipdrv);
+}
+
+module_init(map_ram_init);
+module_exit(map_ram_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("MTD chip driver for RAM chips");