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st,stm32-dmamux

Vendor: STMicroelectronics

Description

These nodes are “dmamux” bus nodes.

STM32 DMAMUX controller

The STM32 DMAMUX is a direct memory access multiplexer
capable of supporting independent DMA channels.
DMAMUX clients connected to the STM32 DMA ultiplexer must use a two-cell specifier
for each dmamux channel: a phandle to the DMA multiplexer plus the following 2 integer cells:
  1. channel: the mux channel from 0 to <dma-channels> - 1
  2. slot: the request line Multiplexer ID
  3. channel-config: A 32bit mask specifying the DMA channel configuration
  which is device dependent:
      -bit 6-7 : Direction  (see dma.h)
             0x0: MEM to MEM
             0x1: MEM to PERIPH
             0x2: PERIPH to MEM
             0x3: reserved for PERIPH to PERIPH
      -bit 9 : Peripheral Increment Address
             0x0: no address increment between transfers
             0x1: increment address between transfers
      -bit 10 : Memory Increment Address
             0x0: no address increment between transfers
             0x1: increment address between transfers
      -bit 11-12 : Peripheral data size
             0x0: Byte (8 bits)
             0x1: Half-word (16 bits)
             0x2: Word (32 bits)
             0x3: reserved
      -bit 13-14 : Memory data size
             0x0: Byte (8 bits)
             0x1: Half-word (16 bits)
             0x2: Word (32 bits)
             0x3: reserved
      -bit 15: Peripheral Increment Offset Size not USED for DMA V2
             0x0: offset size is linked to the peripheral bus width
             0x1: offset size is fixed to 4 (32-bit alignment)
      -bit 16-17 : Priority level
             0x0: low
             0x1: medium
             0x2: high
             0x3: very high
 exemple for stm32wb55x
   dmamux1: dmamux@40020800 {
       compatible = "st,stm32-dmamux";
       ...
       dma-channels = <14>;
       dma-generators = <4>;
       dma-requests= <36>;
       status = "disabled";
       label = "DMAMUX_1";
      };
  for client SPI of stm32wb55x
   spi1: spi@40013000 {
       compatible = "st,stm32-spi";
       dmas = <&dmamux1 11 7 0x20440
                &dmamux1 1 6 0x20480>;
       dma-names = "tx", "rx";
      };

Properties

Node specific properties

Deprecated node specific properties

Base properties

Properties not inherited from the base binding file.

Name

Type

Details

#dma-cells

int

 
Number of items to expect in a DMA specifier (see dma V2)

This property is required.

Constant value: 3

dma-channels

int

 
Number of DMAMUX output request channels supported by the controller

This property is required.

dma-generators

int

 
Number of DMAMUX Request generator supported by the controller

dma-requests

int

 
Number of DMAMUX Peripheral Request Line inputs supported by the controller
This is not directly the value to program in the DMAREQ_ID of the DMAMUX_CxCR

This property is required.

Deprecated properties not inherited from the base binding file.

(None)

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 “st,stm32-dmamux” compatible.

Name

Type

Details

reg

array

 
register space

This property is required.

See Important properties for more information.

interrupts

array

 
interrupts for device

This property is required.

See Important properties for more information.

label

string

 
Human readable string describing the device (used as device_get_binding() argument)

This property is required.

See Important properties for more information.

status

string

 
indicates the operational status of a device

Legal values: 'ok', 'okay', 'disabled', 'reserved', 'fail', 'fail-sss'

See Important properties for more information.

compatible

string-array

 
compatible strings

This property is required.

See Important properties for more information.

reg-names

string-array

 
name of each register space

interrupts-extended

compound

 
extended interrupt specifier for device

interrupt-names

string-array

 
name of each interrupt

interrupt-parent

phandle

 
phandle to interrupt controller node

clocks

phandle-array

 
Clock gate information

clock-names

string-array

 
name of each clock

#address-cells

int

 
number of address cells in reg property

#size-cells

int

 
number of size cells in reg property

dmas

phandle-array

 
DMA channels specifiers

dma-names

string-array

 
Provided names of DMA channel specifiers

io-channels

phandle-array

 
IO channels specifiers

io-channel-names

string-array

 
Provided names of IO channel specifiers

mboxes

phandle-array

 
mailbox / IPM channels specifiers

mbox-names

string-array

 
Provided names of mailbox / IPM channel specifiers

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.

power-domain

phandle

 
Power domain the device belongs to.

The device will be notified when the power domain it belongs to is either
suspended or resumed.

Specifier cell names

  • dma cells: channel, slot, channel-config