2016-07-20 14:44 GMT+02:00 Rob Herring [off-list ref]:

On Tue, Jul 19, 2016 at 03:36:34PM +0200, Mirza Krak wrote:

quoted

From: Mirza Krak <redacted>

Document the devicetree bindings for NOR bus driver found on Tegra20 and
Tegra30 SOCs

Signed-off-by: Mirza Krak <redacted>
---
 .../devicetree/bindings/bus/nvidia,tegra20-nor.txt | 73 ++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/nvidia,tegra20-nor.txt

diff --git a/Documentation/devicetree/bindings/bus/nvidia,tegra20-nor.txt b/Documentation/devicetree/bindings/bus/nvidia,tegra20-nor.txt
new file mode 100644
index 0000000..9ee4a66
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/nvidia,tegra20-nor.txt

@@ -0,0 +1,73 @@
+Device tree bindings for NVIDIA Tegra20/30 NOR Bus
+
+The NOR controller supports a number of memory types, including synchronous NOR,
+asynchronous NOR, and other flash memories with similar interfaces, such as
+MuxOneNAND. One could also connect high speed devices like FPGAs, DSPs,
+CAN chips, Wi-Fi chips etc.
+
+The actual devices are instantiated from the child nodes of a NOR node.
+
+Required properties:
+
+ - compatible: should be "nvidia,tegra20-nor", "nvidia,tegra30-nor"
+ - reg: Should contain NOR controller registers location and length.
+ - clocks: Must contain one entry, for the module clock.
+   See ../clocks/clock-bindings.txt for details.
+ - resets : Must contain an entry for each entry in reset-names.
+   See ../reset/reset.txt for details.
+ - reset-names : Must include the following entries:
+  - nor
+ - #address-cells: Must be set to 2 to allow memory address translation
+ - #size-cells:      Must be set to 1 to allow CS address passing
+ - ranges: Must be set up to reflect the memory layout with four integer
+             values for each chip-select line in use.
+ - nvidia,config: This property represents the SNOR_CONFIG_0 register.
+
+Note that the NOR controller does not have any internal chip-select address
+decoding and if you want to access multiple devices external chip-select
+decoding must be provided.

Then what are the 2 chip selects in ranges?

Rob

Those two chip selects are actually a representation of a external
decoding logic based on what we use on our board. Even though it the
NOR controller only supports one single chip select I wanted to give
an example on how one could create more chip-selects with an external
logic and what it would look like in the device tree representation.

I realize that the bindings should include above explanation or
something similar.

-- 
Med V?nliga H?lsningar / Best Regards

Mirza Krak
mirza.krak at gmail.com
Mobile: +46730280622