realtek,bee-dma

Description

These nodes are “dma” bus nodes.

Bee DMA controller.

channel: Select channel for data transmitting

slot: Handshake index.

config: A 32bit mask specifying the DMA channel configuration
  - bit 0-1:     Direction  (see dma.h)
               - 0x0: MEMORY to MEMORY
               - 0x1: MEMORY to PERIPH
               - 0x2: PERIPH to MEMORY
               - 0x3: PERIPH to PERIPH(reserved)

  - bit 2-3:     Source address increase
               - 0x0: increment address between transfers
               - 0x1: decrement address between transfers
               - 0x2: no address increment between transfers
               - 0x3: reserved

  - bit 4-5:     Destination address increase
               - 0x0: increment address between transfers
               - 0x1: decrement address between transfers
               - 0x2: no address increment between transfers
               - 0x3: reserved

  - bit 6-7:     Source data width
               - 0x0: 8 bits
               - 0x1: 16 bits
               - 0x2: 32 bits
               - 0x3: reserved

  - bit 8-9:     Destination data width
               - 0x0: 8 bits
               - 0x1: 16 bits
               - 0x2: 32 bits
               - 0x3: reserved

  - bit 10-12:   Source data msize
               - 0x0: msize 1
               - 0x1: msize 4
               - 0x2: msize 8
               - 0x3: msize 16
               - 0x4: msize 32
               - 0x5: msize 64
               - 0x6: msize 128
               - 0x7: msize 256

  - bit 13-15:   Destination data width
               - 0x0: msize 1
               - 0x1: msize 4
               - 0x2: msize 8
               - 0x3: msize 16
               - 0x4: msize 32
               - 0x5: msize 64
               - 0x6: msize 128
               - 0x7: msize 256

  - bit 16-20:   Priority
               - 0 ~ 9 can be configured

Example of devicetree configuration

&uart2 {
      status = "okay";
      dmas = <&dma0 2 4 0x10021>, <&dma0 3 5 0xa>;
      dma-names = "tx", "rx";
};

"uart2" uses dma0 for transmitting and receiving in the example.
Each is named "tx" and "rx".
The channel cell assigns channel 2 to transmit and channel 3 to receive.
The slot cell configs specified handshake for different peripherals.
The config cell can take various configs.
But the setting used depends on each driver implementation.
Set the priority for the transmitting channel as HIGH, LOW(the default) for receive channel.

Properties

Properties not inherited from the base binding file.

Name	Type	Details
`dma-channels`	`int`	Number of DMA channels supported by the controller This property is required.
`dma-port`	`int`	This property is required.
`#dma-cells`	`int`	Number of items to expect in a DMA specifier This property is required. Constant value: `3`
`dma-channel-mask`	`int`	Bitmask of available DMA channels in ascending order that are not reserved by firmware and are available to the kernel. i.e. first channel corresponds to LSB.
`dma-requests`	`int`	Number of DMA request signals supported by the controller.
`dma-buf-addr-alignment`	`int`	Memory address alignment requirement for DMA buffers used by the controller.
`dma-buf-size-alignment`	`int`	Memory size alignment requirement for DMA buffers used by the controller.
`dma-copy-alignment`	`int`	Minimal chunk of data possible to be copied by the controller.

Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the “realtek,bee-dma” compatible.

Name	Type	Details
`reg`	`array`	Information used to address the device. The value is specific to the device (i.e. is different depending on the compatible property). The "reg" property is typically a sequence of (address, length) pairs. Each pair is called a "register block". Values are conventionally written in hex. For details, see "2.3.6 reg" in Devicetree Specification v0.4. This property is required. See Important properties for more information.
`interrupts`	`array`	Information about interrupts generated by the device, encoded as an array of one or more interrupt specifiers. The format of the data in this property varies by where the device appears in the interrupt tree. Devices with the same "interrupt-parent" will use the same format in their interrupts properties. For details, see "2.4 Interrupts and Interrupt Mapping" in Devicetree Specification v0.4. This property is required. See Important properties for more information.
`clocks`	`phandle-array`	Information about the device's clock providers. In general, this property should follow conventions established in the dt-schema binding: https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/clock/clock.yaml This property is required.
`status`	`string`	Indicates the operational status of the hardware or other resource that the node represents. In particular: - "okay" means the resource is operational and, for example, can be used by device drivers - "disabled" means the resource is not operational and the system should treat it as if it is not present For details, see "2.3.4 status" in Devicetree Specification v0.4. Legal values: `okay`, `disabled`, `reserved`, `fail`, `fail-sss` See Important properties for more information.
`compatible`	`string-array`	This property is a list of strings that essentially define what type of hardware or other resource this devicetree node represents. Each device driver checks for specific compatible property values to find the devicetree nodes that represent resources that the driver should manage. The recommended format is "vendor,device", The "vendor" part is an abbreviated name of the vendor. The "device" is usually from the datasheet. The compatible property can have multiple values, ordered from most- to least-specific. Having additional values is useful when the device is a specific instance of a more general family, to allow the system to match the most specific driver available. For details, see "2.3.1 compatible" in Devicetree Specification v0.4. This property is required. See Important properties for more information.
`reg-names`	`string-array`	Optional names given to each register block in the "reg" property. For example: / { soc { #address-cells = <1>; #size-cells = <1>; uart@1000 { reg = <0x1000 0x2000>, <0x3000 0x4000>; reg-names = "foo", "bar"; }; }; }; The uart@1000 node has two register blocks: - one with base address 0x1000, size 0x2000, and name "foo" - another with base address 0x3000, size 0x4000, and name "bar"
`interrupts-extended`	`compound`	Extended interrupt specifier for device, used as an alternative to the "interrupts" property. For details, see "2.4 Interrupts and Interrupt Mapping" in Devicetree Specification v0.4.
`interrupt-names`	`string-array`	Optional names given to each interrupt generated by a device. The interrupts themselves are defined in either "interrupts" or "interrupts-extended" properties. For details, see "2.4 Interrupts and Interrupt Mapping" in Devicetree Specification v0.4.
`interrupt-parent`	`phandle`	If present, this refers to the node which handles interrupts generated by this device. For details, see "2.4 Interrupts and Interrupt Mapping" in Devicetree Specification v0.4.
`label`	`string`	Human readable string describing the device. Use of this property is deprecated except as needed on a case-by-case basis. For details, see "4.1.2 Miscellaneous Properties" in Devicetree Specification v0.4. See Important properties for more information.
`clock-names`	`string-array`	Optional names given to each clock provider in the "clocks" property.
`#address-cells`	`int`	This property encodes the number of <u32> cells used by address fields in "reg" properties in this node's children. For details, see "2.3.5 #address-cells and #size-cells" in Devicetree Specification v0.4.
`#size-cells`	`int`	This property encodes the number of <u32> cells used by size fields in "reg" properties in this node's children. For details, see "2.3.5 #address-cells and #size-cells" in Devicetree Specification v0.4.
`dma-coherent`	`boolean`	Indicates that the device is capable of coherent DMA operations. For details, see "2.3.10 dma-coherent" in Devicetree Specification v0.4.
`dmas`	`phandle-array`	DMA channel specifiers relevant to the device.
`dma-names`	`string-array`	Optional names given to the DMA channel specifiers in the "dmas" property.
`io-channels`	`phandle-array`	IO channel specifiers relevant to the device.
`io-channel-names`	`string-array`	Optional names given to the IO channel specifiers in the "io-channels" property.
`mboxes`	`phandle-array`	Mailbox / IPM channel specifiers relevant to the device.
`mbox-names`	`string-array`	Optional names given to the mbox specifiers in the "mboxes" property.
`power-domains`	`phandle-array`	Power domain specifiers relevant to the device.
`power-domain-names`	`string-array`	Optional names given to the power domain specifiers in the "power-domains" property.
`#power-domain-cells`	`int`	Number of cells in power-domains property
`hwlocks`	`phandle-array`	HW spinlock id relevant to the device.
`hwlock-names`	`string-array`	Optional names given to the hwlock specifiers in the "hwlocks" property.
`zephyr,deferred-init`	`boolean`	Do not initialize device automatically on boot. Device should be manually initialized using device_init().
`wakeup-source`	`boolean`	Property to identify that a device can be used as wake up source. When this property is provided a specific flag is set into the device that tells the system that the device is capable of wake up the system. Wake up capable devices are disabled (interruptions will not wake up the system) by default but they can be enabled at runtime if necessary.
`zephyr,pm-device-runtime-auto`	`boolean`	Automatically configure the device for runtime power management after the init function runs.
`zephyr,disabling-power-states`	`phandles`	List of power states that will disable this device power.

Specifier cell names

dma cells: channel, slot, config