On Fri, Aug 07, 2020 at 07:20:06PM +0300, Peter De Schrijver wrote:
> Tegra234 will use DRAM to store the messages exchanged between Linux and
> BPMP firmware rather than sysram as used in Tegra186 and Tegra194. The
> kernel will be informed about the size and location of the DRAM area to
> be used using the DT reserved memory bindings.
>
Plans have changed so also on Tegra234 the IPC messages will be stored
in sysram, hence these patches can be ignored.
Peter.
> Signed-off-by: Peter De Schrijver <pdeschrijver@xxxxxxxxxx>
> ---
> .../firmware/nvidia,tegra186-bpmp.txt | 38 ++++++++++++++++++-
> .../reserved-memory/tegra234-bpmp-shmem.txt | 33 ++++++++++++++++
> 2 files changed, 69 insertions(+), 2 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/reserved-memory/tegra234-bpmp-shmem.txt
>
> diff --git a/Documentation/devicetree/bindings/firmware/nvidia,tegra186-bpmp.txt b/Documentation/devicetree/bindings/firmware/nvidia,tegra186-bpmp.txt
> index ff380dadb5f9..ff8fc4b6816d 100644
> --- a/Documentation/devicetree/bindings/firmware/nvidia,tegra186-bpmp.txt
> +++ b/Documentation/devicetree/bindings/firmware/nvidia,tegra186-bpmp.txt
> @@ -13,12 +13,18 @@ Required properties:
> One of:
> - "nvidia,tegra186-bpmp"
> - mboxes : The phandle of mailbox controller and the mailbox specifier.
> -- shmem : List of the phandle of the TX and RX shared memory area that
> - the IPC between CPU and BPMP is based on.
> - #clock-cells : Should be 1.
> - #power-domain-cells : Should be 1.
> - #reset-cells : Should be 1.
>
> +Optinal properties:
> +- shmem : List of the phandle of the TX and RX shared memory area that
> + the IPC between CPU and BPMP is based on.
> +- memory-region : phandle to reserved memory region used for IPC between
> + CPU-NS and BPMP.
> +One 1 of the above 2 properties must be present. In case both are present
> +memory-region will take precedence and shmem will be ignored.
> +
> This node is a mailbox consumer. See the following files for details of
> the mailbox subsystem, and the specifiers implemented by the relevant
> provider(s):
> @@ -105,3 +111,31 @@ bpmp {
> ...
> };
> };
> +
> +memory-region binding for BPMP
> +------------------------------
> +
> +The shared memory area for the IPC TX and RX between CPU-NS and BPMP
> +resides in normal SDRAM and is defined using a sub-node of the reserved-memory
> +node. See ../reserved-memory/nvidia,tegra234-bpmp-shmem.txt for binding.
> +
> +Example:
> +
> +hsp_top: hsp@3c00000 {
> + ...
> + #mbox-cells = <2>;
> +};
> +
> +bpmp: bpmp {
> + compatible = "nvidia,tegra234-bpmp", "nvidia,tegra186-bpmp";
> + mboxes = <&hsp_top TEGRA_HSP_MBOX_TYPE_DB TEGRA_HSP_DB_MASTER_BPMP>;
> + memory-region = <&dram_cpu_bpmp_mail>;
> + #clock-cells = <1>;
> + #reset-cells = <1>;
> + #power-domain-cells = <1>;
> +
> + i2c {
> + compatible = "...";
> + ...
> + };
> +};
> diff --git a/Documentation/devicetree/bindings/reserved-memory/tegra234-bpmp-shmem.txt b/Documentation/devicetree/bindings/reserved-memory/tegra234-bpmp-shmem.txt
> new file mode 100644
> index 000000000000..44338184d94b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/reserved-memory/tegra234-bpmp-shmem.txt
> @@ -0,0 +1,33 @@
> +* Tegra CPU-NS - BPMP IPC reserved memory binding
> +
> +Define a memory region used for communication between CPU-NS and BPMP.
> +Typically this node is created by the bootloader as the physical address
> +has to be known to both CPU-NS and BPMP for correct IPC operation.
> +
> +The memory region is defined using a child node under /reserved-memory.
> +The sub-node is named shmem@<address> and has the following properties:
> +
> +- compatible:
> + compatible = "nvidia,tegra234-bpmp-shmem";
> +
> +- reg:
> + The physical address and size of the shared SDRAM region
> +
> +- no-map:
> + To prevent the OS from creating a virtual mapping for this region.
> + (See reserved-memory.txt for deatils on the no-map property)
> +
> +Example:
> +
> +/ {
> + reserved-memory {
> + ...
> + dram_cpu_bpmp_mail: shmem@0xf1be0000 {
> + compatible = "nvidia,tegra234-bpmp-shmem";
> + reg = <0x0 0xf1be0000 0x0 0x2000>;
> + no-map;
> + };
> +
> + ...
> + };
> +};
> --
> 2.17.1
>
