Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / mtd / chips / chipreg.c

diff --git a/kernel/drivers/mtd/chips/chipreg.c b/kernel/drivers/mtd/chips/chipreg.c
new file mode 100644 (file)
index 0000000..0bbc61b
--- /dev/null
+++ b/kernel/drivers/mtd/chips/chipreg.c
@@ -0,0 +1,104 @@
+/*
+ * Registration for chip drivers
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/mtd.h>
+
+static DEFINE_SPINLOCK(chip_drvs_lock);
+static LIST_HEAD(chip_drvs_list);
+
+void register_mtd_chip_driver(struct mtd_chip_driver *drv)
+{
+       spin_lock(&chip_drvs_lock);
+       list_add(&drv->list, &chip_drvs_list);
+       spin_unlock(&chip_drvs_lock);
+}
+
+void unregister_mtd_chip_driver(struct mtd_chip_driver *drv)
+{
+       spin_lock(&chip_drvs_lock);
+       list_del(&drv->list);
+       spin_unlock(&chip_drvs_lock);
+}
+
+static struct mtd_chip_driver *get_mtd_chip_driver (const char *name)
+{
+       struct list_head *pos;
+       struct mtd_chip_driver *ret = NULL, *this;
+
+       spin_lock(&chip_drvs_lock);
+
+       list_for_each(pos, &chip_drvs_list) {
+               this = list_entry(pos, typeof(*this), list);
+
+               if (!strcmp(this->name, name)) {
+                       ret = this;
+                       break;
+               }
+       }
+       if (ret && !try_module_get(ret->module))
+               ret = NULL;
+
+       spin_unlock(&chip_drvs_lock);
+
+       return ret;
+}
+
+       /* Hide all the horrid details, like some silly person taking
+          get_module_symbol() away from us, from the caller. */
+
+struct mtd_info *do_map_probe(const char *name, struct map_info *map)
+{
+       struct mtd_chip_driver *drv;
+       struct mtd_info *ret;
+
+       drv = get_mtd_chip_driver(name);
+
+       if (!drv && !request_module("%s", name))
+               drv = get_mtd_chip_driver(name);
+
+       if (!drv)
+               return NULL;
+
+       ret = drv->probe(map);
+
+       /* We decrease the use count here. It may have been a
+          probe-only module, which is no longer required from this
+          point, having given us a handle on (and increased the use
+          count of) the actual driver code.
+       */
+       module_put(drv->module);
+
+       return ret;
+}
+/*
+ * Destroy an MTD device which was created for a map device.
+ * Make sure the MTD device is already unregistered before calling this
+ */
+void map_destroy(struct mtd_info *mtd)
+{
+       struct map_info *map = mtd->priv;
+
+       if (map->fldrv->destroy)
+               map->fldrv->destroy(mtd);
+
+       module_put(map->fldrv->module);
+
+       kfree(mtd);
+}
+
+EXPORT_SYMBOL(register_mtd_chip_driver);
+EXPORT_SYMBOL(unregister_mtd_chip_driver);
+EXPORT_SYMBOL(do_map_probe);
+EXPORT_SYMBOL(map_destroy);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers");