[PATCH 10/14] misc: Implement nvmem interface

[Sean Anderson]

This adds nvmem support for misc devices. Short reads/writes are not
allowed, so we need to translate the return code a bit. This breaks the API
slightly, because the original buffer shouldn't be touched if we fail while
writing. If this becomes an issue, we can add a bounce buffer here.

Signed-off-by: Sean Anderson <sean.anderson at seco.com>
---

 drivers/misc/misc-uclass.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/misc/misc-uclass.c b/drivers/misc/misc-uclass.c
index cfe9d562fa..6bbc78c38a 100644
--- a/drivers/misc/misc-uclass.c
+++ b/drivers/misc/misc-uclass.c
@@ -9,6 +9,7 @@
 #include <dm.h>
 #include <errno.h>
 #include <misc.h>
+#include <nvmem.h>
 
 /*
  * Implement a  miscellaneous uclass for those do not fit other more
@@ -74,3 +75,33 @@ UCLASS_DRIVER(misc) = {
 	.post_bind	= dm_scan_fdt_dev,
 #endif
 };
+
+static int misc_nvmem_read(struct udevice *dev, unsigned int offset, void *buf,
+			   size_t size)
+{
+	int ret = misc_read(dev, offset, buf, size);
+
+	if (ret < 0)
+		return ret;
+	if (ret != size)
+		return -EIO;
+	return 0;
+}
+
+static int misc_nvmem_write(struct udevice *dev, unsigned int offset,
+			    const void *buf, size_t size)
+{
+	int ret = misc_write(dev, offset, buf, size);
+
+	if (ret < 0)
+		return ret;
+	if (ret != size)
+		return -EIO;
+	return 0;
+}
+
+NVMEM_INTERFACE(misc) = {
+	.id = UCLASS_MISC,
+	.read = misc_nvmem_read,
+	.write = misc_nvmem_write,
+};
-- 
2.25.1