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>

1 files changed, 56 insertions, 0 deletions

diff --git a/doc/device-tree-bindings/nvmxip/nvmxip_qspi.txt b/doc/device-tree-bindings/nvmxip/nvmxip_qspi.txt
new file mode 100644
index 0000000..cc60e9e
--- /dev/null
+++ b/doc/device-tree-bindings/nvmxip/nvmxip_qspi.txt
@@ -0,0 +1,56 @@
+Specifying NVMXIP information for devices
+======================================
+
+QSPI XIP flash device nodes
+---------------------------
+
+Each flash device should have its own node.
+
+Each node must specify the following fields:
+
+1)
+		compatible = "nvmxip,qspi";
+
+This allows to bind the flash device with the nvmxip_qspi driver
+If a platform has its own driver, please provide your own compatible
+string.
+
+2)
+		reg = <0x0 0x08000000 0x0 0x00200000>;
+
+The start address and size of the flash device. The values give here are an
+example (when the cell size is 2).
+
+When cell size is 1, the reg field looks like this:
+
+		reg = <0x08000000 0x00200000>;
+
+3)
+
+		lba_shift = <9>;
+
+The number of bit shifts used to calculate the size in bytes of one block.
+In this example the block size is 1 << 9 = 2 ^ 9 = 512 bytes
+
+4)
+
+		lba = <4096>;
+
+The number of blocks.
+
+Example of multiple flash devices
+----------------------------------------------------
+
+	nvmxip-qspi1@08000000 {
+		compatible = "nvmxip,qspi";
+		reg = <0x0 0x08000000 0x0 0x00200000>;
+		lba_shift = <9>;
+		lba = <4096>;
+	};
+
+	nvmxip-qspi2@08200000 {
+		compatible = "nvmxip,qspi";
+		reg = <0x0 0x08200000 0x0 0x00100000>;
+		lba_shift = <9>;
+		lba = <2048>;
+	};