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Diffstat (limited to 'drivers/mtd/devices/mtdram.c')
-rw-r--r--drivers/mtd/devices/mtdram.c187
1 files changed, 187 insertions, 0 deletions
diff --git a/drivers/mtd/devices/mtdram.c b/drivers/mtd/devices/mtdram.c
new file mode 100644
index 000000000..1c97fabc4
--- /dev/null
+++ b/drivers/mtd/devices/mtdram.c
@@ -0,0 +1,187 @@
+/*
+ * mtdram - a test mtd device
+ * Author: Alexander Larsson <alex@cendio.se>
+ *
+ * Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
+ * Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de>
+ *
+ * This code is GPL
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/mtdram.h>
+
+static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
+static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
+static unsigned long writebuf_size = 64;
+#define MTDRAM_TOTAL_SIZE (total_size * 1024)
+#define MTDRAM_ERASE_SIZE (erase_size * 1024)
+
+module_param(total_size, ulong, 0);
+MODULE_PARM_DESC(total_size, "Total device size in KiB");
+module_param(erase_size, ulong, 0);
+MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
+module_param(writebuf_size, ulong, 0);
+MODULE_PARM_DESC(writebuf_size, "Device write buf size in Bytes (Default: 64)");
+
+// We could store these in the mtd structure, but we only support 1 device..
+static struct mtd_info *mtd_info;
+
+static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+ int ret = 0;
+
+ /* Start address must align on block boundary */
+ if (mtd_mod_by_eb(ofs, mtd)) {
+ pr_debug("%s: unaligned address\n", __func__);
+ ret = -EINVAL;
+ }
+
+ /* Length must align on block boundary */
+ if (mtd_mod_by_eb(len, mtd)) {
+ pr_debug("%s: length not block aligned\n", __func__);
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+ if (check_offs_len(mtd, instr->addr, instr->len))
+ return -EINVAL;
+ memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
+
+ return 0;
+}
+
+static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
+ size_t *retlen, void **virt, resource_size_t *phys)
+{
+ *virt = mtd->priv + from;
+ *retlen = len;
+
+ if (phys) {
+ /* limit retlen to the number of contiguous physical pages */
+ unsigned long page_ofs = offset_in_page(*virt);
+ void *addr = *virt - page_ofs;
+ unsigned long pfn1, pfn0 = vmalloc_to_pfn(addr);
+
+ *phys = __pfn_to_phys(pfn0) + page_ofs;
+ len += page_ofs;
+ while (len > PAGE_SIZE) {
+ len -= PAGE_SIZE;
+ addr += PAGE_SIZE;
+ pfn0++;
+ pfn1 = vmalloc_to_pfn(addr);
+ if (pfn1 != pfn0) {
+ *retlen = addr - *virt;
+ break;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+ return 0;
+}
+
+static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
+ size_t *retlen, u_char *buf)
+{
+ memcpy(buf, mtd->priv + from, len);
+ *retlen = len;
+ return 0;
+}
+
+static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, const u_char *buf)
+{
+ memcpy((char *)mtd->priv + to, buf, len);
+ *retlen = len;
+ return 0;
+}
+
+static void __exit cleanup_mtdram(void)
+{
+ if (mtd_info) {
+ mtd_device_unregister(mtd_info);
+ vfree(mtd_info->priv);
+ kfree(mtd_info);
+ }
+}
+
+int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
+ unsigned long size, const char *name)
+{
+ memset(mtd, 0, sizeof(*mtd));
+
+ /* Setup the MTD structure */
+ mtd->name = name;
+ mtd->type = MTD_RAM;
+ mtd->flags = MTD_CAP_RAM;
+ mtd->size = size;
+ mtd->writesize = 1;
+ mtd->writebufsize = writebuf_size;
+ mtd->erasesize = MTDRAM_ERASE_SIZE;
+ mtd->priv = mapped_address;
+
+ mtd->owner = THIS_MODULE;
+ mtd->_erase = ram_erase;
+ mtd->_point = ram_point;
+ mtd->_unpoint = ram_unpoint;
+ mtd->_read = ram_read;
+ mtd->_write = ram_write;
+
+ if (mtd_device_register(mtd, NULL, 0))
+ return -EIO;
+
+ return 0;
+}
+
+static int __init init_mtdram(void)
+{
+ void *addr;
+ int err;
+
+ if (!total_size)
+ return -EINVAL;
+
+ /* Allocate some memory */
+ mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
+ if (!mtd_info)
+ return -ENOMEM;
+
+ addr = vmalloc(MTDRAM_TOTAL_SIZE);
+ if (!addr) {
+ kfree(mtd_info);
+ mtd_info = NULL;
+ return -ENOMEM;
+ }
+ err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
+ if (err) {
+ vfree(addr);
+ kfree(mtd_info);
+ mtd_info = NULL;
+ return err;
+ }
+ memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
+ return err;
+}
+
+module_init(init_mtdram);
+module_exit(cleanup_mtdram);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
+MODULE_DESCRIPTION("Simulated MTD driver for testing");