# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/firmware/nvidia,tegra186-bpmp.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: NVIDIA Tegra Boot and Power Management Processor (BPMP)
maintainers:
- Thierry Reding <thierry.reding@gmail.com>
- Jon Hunter <jonathanh@nvidia.com>
description: |
The BPMP is a specific processor in Tegra chip, which is designed for
booting process handling and offloading the power management, clock
management, and reset control tasks from the CPU. The binding document
defines the resources that would be used by the BPMP firmware driver,
which can create the interprocessor communication (IPC) between the
CPU and BPMP.
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):
- .../mailbox/mailbox.txt
- .../mailbox/nvidia,tegra186-hsp.yaml
This node is a clock, power domain, and reset provider. See the
following files for general documentation of those features, and the
specifiers implemented by this node:
- .../clock/clock-bindings.txt
- <dt-bindings/clock/tegra186-clock.h>
- ../power/power-domain.yaml
- <dt-bindings/power/tegra186-powergate.h>
- .../reset/reset.txt
- <dt-bindings/reset/tegra186-reset.h>
The BPMP implements some services which must be represented by
separate nodes. For example, it can provide access to certain I2C
controllers, and the I2C bindings represent each I2C controller as a
device tree node. Such nodes should be nested directly inside the main
BPMP node.
Software can determine whether a child node of the BPMP node
represents a device by checking for a compatible property. Any node
with a compatible property represents a device that can be
instantiated. Nodes without a compatible property may be used to
provide configuration information regarding the BPMP itself, although
no such configuration nodes are currently defined by this binding.
The BPMP firmware defines no single global name-/numbering-space for
such services. Put another way, the numbering scheme for I2C buses is
distinct from the numbering scheme for any other service the BPMP may
provide (e.g. a future hypothetical SPI bus service). As such, child
device nodes will have no reg property, and the BPMP node will have no
"#address-cells" or "#size-cells" property.
The shared memory area for the IPC TX and RX between CPU and BPMP are
predefined and work on top of either sysram, which is an SRAM inside the
chip, or in normal SDRAM.
See ".../sram/sram.yaml" for the bindings for the SRAM case.
See "../reserved-memory/nvidia,tegra264-bpmp-shmem.yaml" for bindings for
the SDRAM case.
properties:
compatible:
oneOf:
- items:
- enum:
- nvidia,tegra194-bpmp
- nvidia,tegra234-bpmp
- const: nvidia,tegra186-bpmp
- const: nvidia,tegra186-bpmp
mboxes:
description: A phandle and channel specifier for the mailbox used to
communicate with the BPMP.
maxItems: 1
shmem:
description: List of the phandle to the TX and RX shared memory area
that the IPC between CPU and BPMP is based on.
minItems: 2
maxItems: 2
memory-region:
description: phandle to reserved memory region used for IPC between
CPU-NS and BPMP.
maxItems: 1
"#clock-cells":
const: 1
"#power-domain-cells":
const: 1
"#reset-cells":
const: 1
interconnects:
items:
- description: memory read client
- description: memory write client
- description: DMA read client
- description: DMA write client
interconnect-names:
items:
- const: read
- const: write
- const: dma-mem # dma-read
- const: dma-write
iommus:
maxItems: 1
i2c:
type: object
thermal:
type: object
additionalProperties: false
oneOf:
- required:
- memory-region
- required:
- shmem
required:
- compatible
- mboxes
- "#clock-cells"
- "#power-domain-cells"
- "#reset-cells"
examples:
- |
#include <dt-bindings/interrupt-controller/arm-gic.h>
#include <dt-bindings/mailbox/tegra186-hsp.h>
#include <dt-bindings/memory/tegra186-mc.h>
hsp_top0: hsp@3c00000 {
compatible = "nvidia,tegra186-hsp";
reg = <0x03c00000 0xa0000>;
interrupts = <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH>;
interrupt-names = "doorbell";
#mbox-cells = <2>;
};
sram@30000000 {
compatible = "nvidia,tegra186-sysram", "mmio-sram";
reg = <0x30000000 0x50000>;
#address-cells = <1>;
#size-cells = <1>;
ranges = <0x0 0x30000000 0x50000>;
cpu_bpmp_tx: sram@4e000 {
reg = <0x4e000 0x1000>;
label = "cpu-bpmp-tx";
pool;
};
cpu_bpmp_rx: sram@4f000 {
reg = <0x4f000 0x1000>;
label = "cpu-bpmp-rx";
pool;
};
};
bpmp {
compatible = "nvidia,tegra186-bpmp";
interconnects = <&mc TEGRA186_MEMORY_CLIENT_BPMPR &emc>,
<&mc TEGRA186_MEMORY_CLIENT_BPMPW &emc>,
<&mc TEGRA186_MEMORY_CLIENT_BPMPDMAR &emc>,
<&mc TEGRA186_MEMORY_CLIENT_BPMPDMAW &emc>;
interconnect-names = "read", "write", "dma-mem", "dma-write";
iommus = <&smmu TEGRA186_SID_BPMP>;
mboxes = <&hsp_top0 TEGRA_HSP_MBOX_TYPE_DB TEGRA_HSP_DB_MASTER_BPMP>;
shmem = <&cpu_bpmp_tx>, <&cpu_bpmp_rx>;
#clock-cells = <1>;
#power-domain-cells = <1>;
#reset-cells = <1>;
i2c {
compatible = "nvidia,tegra186-bpmp-i2c";
nvidia,bpmp-bus-id = <5>;
#address-cells = <1>;
#size-cells = <0>;
};
thermal {
compatible = "nvidia,tegra186-bpmp-thermal";
#thermal-sensor-cells = <1>;
};
};
- |
#include <dt-bindings/mailbox/tegra186-hsp.h>
bpmp {
compatible = "nvidia,tegra186-bpmp";
interconnects = <&mc TEGRA186_MEMORY_CLIENT_BPMPR &emc>,
<&mc TEGRA186_MEMORY_CLIENT_BPMPW &emc>,
<&mc TEGRA186_MEMORY_CLIENT_BPMPDMAR &emc>,
<&mc TEGRA186_MEMORY_CLIENT_BPMPDMAW &emc>;
interconnect-names = "read", "write", "dma-mem", "dma-write";
mboxes = <&hsp_top1 TEGRA_HSP_MBOX_TYPE_DB TEGRA_HSP_DB_MASTER_BPMP>;
memory-region = <&dram_cpu_bpmp_mail>;
#clock-cells = <1>;
#power-domain-cells = <1>;
#reset-cells = <1>;
};