flash: Provide direct flash access with flash_dataptr()

Sometimes it is useful to get access to the flash directly, without using
flash_read(). Add a function to do this.

Since the range checking is done in every function in flash_common,
use the new function to do it for us. That way we get a slight (64 byte)
code size reduction.

BUG=chrome-os-partner:10146
TEST=manual:
build and boot on snow with SPI flash emulation, in U-Boot:

See that the 32KB of flash has been provided correctly.

Change-Id: I6622a24234edaed371dd5b9bf43d1f3974d55e39
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/26174

1 files changed, 37 insertions, 0 deletions

diff --git a/include/flash.h b/include/flash.h
index 9b0a60a5e2..7611639add 100644
--- a/include/flash.h
+++ b/include/flash.h
@@ -24,6 +24,22 @@ int flash_get_protect_block_size(void);
 /* Return the physical size of flash in bytes */
 int flash_physical_size(void);
 
+/**
+ * Get the physical memory address of a flash offset
+ *
+ * This is used for direct flash access. We assume that the flash is
+ * contiguous from this start address through to the end of the usable
+ * flash.
+ *
+ * @param offset	Flash offset to get address of
+ * @param dataptrp	Returns pointer to memory address of flash offset
+ * @return pointer to flash memory offset, if ok, else NULL
+ */
+static inline char *flash_physical_dataptr(int offset)
+{
+	return (char *)offset;
+}
+
 /* Read <size> bytes of data from offset <offset> into <data>. */
 int flash_physical_read(int offset, int size, char *data);
 
@@ -50,6 +66,27 @@ int flash_pre_init(void);
  * smaller than the actual flash size, */
 int flash_get_size(void);
 
+/**
+ * Get the physical memory address of a flash offset
+ *
+ * This is used for direct flash access. We assume that the flash is
+ * contiguous from this start address through to the end of the usable
+ * flash.
+ *
+ * This function returns NULL if offset + size_req extends beyond the end
+ * of flash, or if either size_req or offset are not aligned to 'align'.
+ *
+ * @param offset	Flash offset to get address of
+ * @param size_req	Number of bytes requested
+ * @param align		Ensure offset and size_req are aligned to given
+ *			power of two.
+ * @param sizep		If not NULL, returns amount of flash available at
+ *			this memory addr, unless function fails, iwc it is
+ *			unset.
+ * @return pointer to flash, or NULL on error
+ */
+char *flash_dataptr(int offset, int size_req, int align, int *sizep);
+
 /* Reads <size> bytes of data from offset <offset> into <data>. */
 int flash_read(int offset, int size, char *data);