diff options
Diffstat (limited to 'doc/device-tree-bindings')
3 files changed, 198 insertions, 0 deletions
diff --git a/doc/device-tree-bindings/firmware/nvidia,tegra186-bpmp.txt b/doc/device-tree-bindings/firmware/nvidia,tegra186-bpmp.txt new file mode 100644 index 0000000..447252e --- /dev/null +++ b/doc/device-tree-bindings/firmware/nvidia,tegra186-bpmp.txt @@ -0,0 +1,104 @@ +NVIDIA Tegra Boot and Power Management Processor (BPMP) + +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. + +Required properties: +- name : Should be bpmp +- compatible + Array of strings + 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. + +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.txt + +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.txt +- <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 bindings for BPMP +----------------------------------- + +The shared memory area for the IPC TX and RX between CPU and BPMP are +predefined and work on top of sysram, which is an SRAM inside the chip. + +See ".../sram/sram.txt" for the bindings. + +Example: + +hsp_top0: hsp@03c00000 { + ... + #mbox-cells = <2>; +}; + +sysram@30000000 { + compatible = "nvidia,tegra186-sysram", "mmio-sram"; + reg = <0x0 0x30000000 0x0 0x50000>; + #address-cells = <2>; + #size-cells = <2>; + ranges = <0 0x0 0x0 0x30000000 0x0 0x50000>; + + cpu_bpmp_tx: bpmp_shmem@4e000 { + compatible = "nvidia,tegra186-bpmp-shmem"; + reg = <0x0 0x4e000 0x0 0x1000>; + }; + + cpu_bpmp_rx: bpmp_shmem@4f000 { + compatible = "nvidia,tegra186-bpmp-shmem"; + reg = <0x0 0x4f000 0x0 0x1000>; + }; +}; + +bpmp { + compatible = "nvidia,tegra186-bpmp"; + mboxes = <&hsp_top0 HSP_MBOX_TYPE_DB HSP_DB_MASTER_BPMP>; + shmem = <&cpu_bpmp_tx &cpu_bpmp_rx>; + #clock-cells = <1>; + #power-domain-cells = <1>; + #reset-cells = <1>; + + i2c { + compatible = "..."; + ... + }; +}; diff --git a/doc/device-tree-bindings/i2c/nvidia,tegra186-bpmp-i2c.txt b/doc/device-tree-bindings/i2c/nvidia,tegra186-bpmp-i2c.txt new file mode 100644 index 0000000..ab240e1 --- /dev/null +++ b/doc/device-tree-bindings/i2c/nvidia,tegra186-bpmp-i2c.txt @@ -0,0 +1,42 @@ +NVIDIA Tegra186 BPMP I2C controller + +In Tegra186, the BPMP (Boot and Power Management Processor) owns certain HW +devices, such as the I2C controller for the power management I2C bus. Software +running on other CPUs must perform IPC to the BPMP in order to execute +transactions on that I2C bus. This binding describes an I2C bus that is +accessed in such a fashion. + +The BPMP I2C node must be located directly inside the main BPMP node. See +../firmware/nvidia,tegra186-bpmp.txt for details of the BPMP binding. + +This node represents an I2C controller. See ../i2c/i2c.txt for details of the +core I2C binding. + +Required properties: +- compatible: + Array of strings. + One of: + - "nvidia,tegra186-bpmp-i2c". +- #address-cells: Address cells for I2C device address. + Single-cell integer. + Must be <1>. +- #size-cells: + Single-cell integer. + Must be <0>. +- nvidia,bpmp-bus-id: + Single-cell integer. + Indicates the I2C bus number this DT node represent, as defined by the + BPMP firmware. + +Example: + +bpmp { + ... + + i2c { + compatible = "nvidia,tegra186-bpmp-i2c"; + #address-cells = <1>; + #size-cells = <0>; + nvidia,bpmp-bus-id = <5>; + }; +}; diff --git a/doc/device-tree-bindings/mailbox/nvidia,tegra186-hsp.txt b/doc/device-tree-bindings/mailbox/nvidia,tegra186-hsp.txt new file mode 100644 index 0000000..a915238 --- /dev/null +++ b/doc/device-tree-bindings/mailbox/nvidia,tegra186-hsp.txt @@ -0,0 +1,52 @@ +NVIDIA Tegra Hardware Synchronization Primitives (HSP) + +The HSP modules are used for the processors to share resources and communicate +together. It provides a set of hardware synchronization primitives for +interprocessor communication. So the interprocessor communication (IPC) +protocols can use hardware synchronization primitives, when operating between +two processors not in an SMP relationship. + +The features that HSP supported are shared mailboxes, shared semaphores, +arbitrated semaphores and doorbells. + +Required properties: +- name : Should be hsp +- compatible + Array of strings. + one of: + - "nvidia,tegra186-hsp" +- reg : Offset and length of the register set for the device. +- interrupt-names + Array of strings. + Contains a list of names for the interrupts described by the interrupt + property. May contain the following entries, in any order: + - "doorbell" + Users of this binding MUST look up entries in the interrupt property + by name, using this interrupt-names property to do so. +- interrupts + Array of interrupt specifiers. + Must contain one entry per entry in the interrupt-names property, + in a matching order. +- #mbox-cells : Should be 2. + +The mbox specifier of the "mboxes" property in the client node should +contain two data. The first one should be the HSP type and the second +one should be the ID that the client is going to use. Those information +can be found in the following file. + +- <dt-bindings/mailbox/tegra186-hsp.h>. + +Example: + +hsp_top0: hsp@3c00000 { + compatible = "nvidia,tegra186-hsp"; + reg = <0x0 0x03c00000 0x0 0xa0000>; + interrupts = <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH>; + interrupt-names = "doorbell"; + #mbox-cells = <2>; +}; + +client { + ... + mboxes = <&hsp_top0 HSP_MBOX_TYPE_DB HSP_DB_MASTER_XXX>; +}; |