From e29c22f5abe6e0f4baa6251efed6074cdfc3db79 Mon Sep 17 00:00:00 2001
From: Kyungmin Park <kyungmin.park@samsung.com>
Date: Wed, 19 Nov 2008 16:20:36 +0100
Subject: MTD: Add MTD paritioning infrastructure

This MTD part infrastructure will be used by the upcoming
UBI support.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Stefan Roese <sr@denx.de>
---
 drivers/mtd/mtdcore.c | 146 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 146 insertions(+)
 create mode 100644 drivers/mtd/mtdcore.c

(limited to 'drivers/mtd/mtdcore.c')

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
new file mode 100644
index 0000000..64bd7d4
--- /dev/null
+++ b/drivers/mtd/mtdcore.c
@@ -0,0 +1,146 @@
+/*
+ * Core registration and callback routines for MTD
+ * drivers and users.
+ *
+ * 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.
+ */
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/compat.h>
+#include <ubi_uboot.h>
+
+struct mtd_info *mtd_table[MAX_MTD_DEVICES];
+
+int add_mtd_device(struct mtd_info *mtd)
+{
+	int i;
+
+	BUG_ON(mtd->writesize == 0);
+
+	for (i = 0; i < MAX_MTD_DEVICES; i++)
+		if (!mtd_table[i]) {
+			mtd_table[i] = mtd;
+			mtd->index = i;
+			mtd->usecount = 0;
+
+			printf("mtd: Giving out device %d to %s\n",
+				i, mtd->name);
+			/* No need to get a refcount on the module containing
+			   the notifier, since we hold the mtd_table_mutex */
+
+			/* We _know_ we aren't being removed, because
+			   our caller is still holding us here. So none
+			   of this try_ nonsense, and no bitching about it
+			   either. :) */
+			return 0;
+		}
+
+	return 1;
+}
+
+/**
+ *      del_mtd_device - unregister an MTD device
+ *      @mtd: pointer to MTD device info structure
+ *
+ *      Remove a device from the list of MTD devices present in the system,
+ *      and notify each currently active MTD 'user' of its departure.
+ *      Returns zero on success or 1 on failure, which currently will happen
+ *      if the requested device does not appear to be present in the list.
+ */
+int del_mtd_device(struct mtd_info *mtd)
+{
+	int ret;
+
+	if (mtd_table[mtd->index] != mtd) {
+		ret = -ENODEV;
+	} else if (mtd->usecount) {
+		printk(KERN_NOTICE "Removing MTD device #%d (%s)"
+				" with use count %d\n",
+				mtd->index, mtd->name, mtd->usecount);
+		ret = -EBUSY;
+	} else {
+		/* No need to get a refcount on the module containing
+		 * the notifier, since we hold the mtd_table_mutex */
+		mtd_table[mtd->index] = NULL;
+
+		ret = 0;
+	}
+
+	return ret;
+}
+
+/**
+ *	get_mtd_device - obtain a validated handle for an MTD device
+ *	@mtd: last known address of the required MTD device
+ *	@num: internal device number of the required MTD device
+ *
+ *	Given a number and NULL address, return the num'th entry in the device
+ *      table, if any.  Given an address and num == -1, search the device table
+ *      for a device with that address and return if it's still present. Given
+ *      both, return the num'th driver only if its address matches. Return
+ *      error code if not.
+ */
+struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
+{
+	struct mtd_info *ret = NULL;
+	int i, err = -ENODEV;
+
+	if (num == -1) {
+		for (i = 0; i < MAX_MTD_DEVICES; i++)
+			if (mtd_table[i] == mtd)
+				ret = mtd_table[i];
+	} else if (num < MAX_MTD_DEVICES) {
+		ret = mtd_table[num];
+		if (mtd && mtd != ret)
+			ret = NULL;
+	}
+
+	if (!ret)
+		goto out_unlock;
+
+	ret->usecount++;
+	return ret;
+
+out_unlock:
+	return ERR_PTR(err);
+}
+
+/**
+ *      get_mtd_device_nm - obtain a validated handle for an MTD device by
+ *      device name
+ *      @name: MTD device name to open
+ *
+ *      This function returns MTD device description structure in case of
+ *      success and an error code in case of failure.
+ */
+struct mtd_info *get_mtd_device_nm(const char *name)
+{
+	int i, err = -ENODEV;
+	struct mtd_info *mtd = NULL;
+
+	for (i = 0; i < MAX_MTD_DEVICES; i++) {
+		if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) {
+			mtd = mtd_table[i];
+			break;
+		}
+	}
+
+	if (!mtd)
+		goto out_unlock;
+
+	mtd->usecount++;
+	return mtd;
+
+out_unlock:
+	return ERR_PTR(err);
+}
+
+void put_mtd_device(struct mtd_info *mtd)
+{
+	int c;
+
+	c = --mtd->usecount;
+	BUG_ON(c < 0);
+}
-- 
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