drivers/mtd/nvmxip: introduce QSPI XIP driver
add nvmxip_qspi driver under UCLASS_NVMXIP
The device associated with this driver is the parent of the blk#<id> device
nvmxip_qspi can be reused by other platforms. If the platform
has custom settings to apply before using the flash, then the platform
can provide its own parent driver belonging to UCLASS_NVMXIP and reuse
nvmxip-blk driver. The custom driver can be implemented like nvmxip_qspi in
addition to the platform custom settings.
Platforms can use multiple NVM XIP devices at the same time by defining a
DT node for each one of them.
For more details please refer to doc/develop/driver-model/nvmxip_qspi.rst
Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
diff --git a/doc/develop/driver-model/nvmxip.rst b/doc/develop/driver-model/nvmxip.rst
index fe087b1..09afdbc 100644
--- a/doc/develop/driver-model/nvmxip.rst
+++ b/doc/develop/driver-model/nvmxip.rst
@@ -25,7 +25,33 @@
the Uclass creates a block device and binds it with the nvmxip-blk.
The Uclass driver implemented by drivers/mtd/nvmxip/nvmxip-uclass.c
- The implementation is generic and can be used by different platforms.
+ nvmxip_qspi driver :
+
+ The driver probed with the DT and is the parent of the blk#<id> device.
+ nvmxip_qspi can be reused by other platforms. If the platform
+ has custom settings to apply before using the flash, then the platform
+ can provide its own parent driver belonging to UCLASS_NVMXIP and reuse
+ nvmxip-blk. The custom driver can be implemented like nvmxip_qspi in
+ addition to the platform custom settings.
+ The nvmxip_qspi driver belongs to UCLASS_NVMXIP.
+ The driver implemented by drivers/mtd/nvmxip/nvmxip_qspi.c
+
+ For example, if we have two NVMXIP devices described in the DT
+ The devices hierarchy is as follows:
+
+::
+
+ => dm tree
+
+ Class Index Probed Driver Name
+ -----------------------------------------------------------
+ ...
+ nvmxip 0 [ + ] nvmxip_qspi |-- nvmxip-qspi1@08000000
+ blk 3 [ + ] nvmxip-blk | `-- nvmxip-qspi1@08000000.blk#1
+ nvmxip 1 [ + ] nvmxip_qspi |-- nvmxip-qspi2@08200000
+ blk 4 [ + ] nvmxip-blk | `-- nvmxip-qspi2@08200000.blk#2
+
+The implementation is generic and can be used by different platforms.
Supported hardware
--------------------------------
@@ -43,6 +69,23 @@
handles the read operation. This driver is HW agnostic and can support
multiple flash devices at the same time.
+config NVMXIP_QSPI
+ This option allows the emulation of a block storage device on top of a QSPI XIP flash.
+ Any platform that needs to emulate one or multiple QSPI XIP flash devices can turn this
+ option on to enable the functionality. NVMXIP config is selected automatically.
+ Platforms that need to add custom treatments before accessing to the flash, can
+ write their own driver (same as nvmxip_qspi in addition to the custom settings).
+
+Device Tree nodes
+--------------------
+
+Multiple QSPI XIP flash devices can be used at the same time by describing them through DT
+nodes.
+
+Please refer to the documentation of the DT binding at:
+
+doc/device-tree-bindings/nvmxip/nvmxip_qspi.txt
+
Contributors
------------
* Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>