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authorTom Rini <[email protected]>2023-04-27 19:22:38 -0400
committerTom Rini <[email protected]>2023-04-27 19:22:38 -0400
commitc9c2c95d4cd27fe0cd41fe13a863899d268f973c (patch)
tree3d21d49d97b97f5c8579a43c5d4211f04d6fa4de /doc/device-tree-bindings
parentb197f1f05dee730e173a0756cb1a5f2be5d3ba5b (diff)
parent56722fafd9b2a017930030e9b50c5784f64545db (diff)
Merge branch '2023-04-27-introduce-nvm-xip-block-storage-emulation'
To quote the author: Adding block storage emulation for NVM XIP flash devices. Some paltforms such as Corstone-1000 need to see NVM XIP raw flash as a block storage device with read only capability. Here NVM flash devices are devices with addressable memory (e.g: QSPI NOR flash). The NVM XIP block storage emulation provides the following features: - Emulate NVM XIP raw flash as a block storage device with read only capability - Being generic by design and can be used by any platform - Device tree node - Platforms can use multiple NVM XIP devices at the same time by defining a DT node for each one of them - A generic NVMXIP block driver allowing to read from the XIP flash - A generic NVMXIP Uclass driver for binding the block device - A generic NVMXIP QSPI driver - Implemented on top of memory-mapped IO (using readq macro) - Enabling NVMXIP in sandbox64 - A sandbox test case - Enabling NVMXIP in Corstone1000 platform as a use case For more details please refer to doc/develop/driver-model/nvmxip.rst
Diffstat (limited to 'doc/device-tree-bindings')
-rw-r--r--doc/device-tree-bindings/nvmxip/nvmxip_qspi.txt56
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diff --git a/doc/device-tree-bindings/nvmxip/nvmxip_qspi.txt b/doc/device-tree-bindings/nvmxip/nvmxip_qspi.txt
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index 00000000000..882728d5413
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+++ 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 = /bits/ 64 <0x08000000 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 = /bits/ 64 <0x08000000 0x00200000>;
+ lba_shift = <9>;
+ lba = <4096>;
+ };
+
+ nvmxip-qspi2@08200000 {
+ compatible = "nvmxip,qspi";
+ reg = /bits/ 64 <0x08200000 0x00100000>;
+ lba_shift = <9>;
+ lba = <2048>;
+ };