cmd: mmc: Add mmc reg read command for reading card registers
Add extension to the 'mmc' command to read out the card registers.
Currently, only the eMMC OCR/CID/CSD/EXTCSD/RCA/DSR register are
supported. A register value can either be displayed or read into
an environment variable.
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/doc/usage/cmd/mmc.rst b/doc/usage/cmd/mmc.rst
index 71a0303..c0924ba 100644
--- a/doc/usage/cmd/mmc.rst
+++ b/doc/usage/cmd/mmc.rst
@@ -21,6 +21,7 @@
mmc bootpart-resize <dev> <dev part size MB> <RPMB part size MB>
mmc partconf <dev> [[varname] | [<boot_ack> <boot_partition> <partition_access>]]
mmc rst-function <dev> <value>
+ mmc reg read <reg> <offset> [env]
Description
-----------
@@ -183,6 +184,31 @@
0x3
Reserved
+The 'mmc reg read <reg> <offset> [env]' reads eMMC card register and
+either print it to standard output, or store the value in environment
+variable.
+
+<reg> with
+optional offset <offset> into the register array, and print it to
+standard output or store it into environment variable [env].
+
+ reg
+ cid
+ The Device IDentification (CID) register. Uses offset.
+ csd
+ The Device-Specific Data (CSD) register. Uses offset.
+ dsr
+ The driver stage register (DSR).
+ ocr
+ The operation conditions register (OCR).
+ rca
+ The relative Device address (RCA) register.
+ extcsd
+ The Extended CSD register. Uses offset.
+ offset
+ For 'cid'/'csd' 128 bit registers '[0..3]' in 32-bit increments. For 'extcsd' 512 bit register '[0..512,all]' in 8-bit increments, or 'all' to read the entire register.
+ env
+ Optional environment variable into which 32-bit value read from register should be stored.
Examples
--------