st,stm32-dma-v2bis
Vendor: STMicroelectronics
Description
These nodes are “dma” bus nodes.
STM32 DMA controller (V2bis) for the stm32F0, stm32F1 and stm32L1 soc families
This DMA controller includes several channels with different requests.
All the requests ar ORed before entering the DMA, so that only one request
must be enabled at a time.
DMA clients connected to the STM32 DMA controller must use the format
described in the dma.txt file, using a 2-cell specifier for each
channel: a phandle to the DMA controller plus the following four integer cells:
1. channel: the dma stream from 1 to <dma-requests>
2. channel-config: A 32bit mask specifying the DMA channel configuration
A name custom DMA flags for channel configuration is used
which is device dependent see stm32_dma.h:
-bit 5 : DMA cyclic mode config
0x0: STM32_DMA_MODE_NORMAL
0x1: STM32_DMA_MODE_CYCLIC
-bit 6-7 : Direction (see dma.h)
0x0: STM32_DMA_MEMORY_TO_MEMORY: MEM to MEM
0x1: STM32_DMA_MEMORY_TO_PERIPH: MEM to PERIPH
0x2: STM32_DMA_PERIPH_TO_MEMORY: PERIPH to MEM
0x3: reserved for PERIPH to PERIPH
-bit 9 : Peripheral Increment Address
0x0: STM32_DMA_PERIPH_NO_INC: no address increment between transfers
0x1: STM32_DMA_PERIPH_INC: increment address between transfers
-bit 10 : Memory Increment Address
0x0: STM32_DMA_MEM_NO_INC: no address increment between transfers
0x1: STM32_DMA_MEM_INC: increment address between transfers
-bit 11-12 : Peripheral data size
0x0: STM32_DMA_PERIPH_8BITS: Byte (8 bits)
0x1: STM32_DMA_PERIPH_16BITS: Half-word (16 bits)
0x2: STM32_DMA_PERIPH_32BITS: Word (32 bits)
0x3: reserved
-bit 13-14 : Memory data size
0x0: STM32_DMA_MEM_8BITS: Byte (8 bits)
0x1: STM32_DMA_MEM_16BITS: Half-word (16 bits)
0x2: STM32_DMA_MEM_32BITS: Word (32 bits)
0x3: reserved
-bit 15: Reserved
-bit 16-17 : Priority level
0x0: STM32_DMA_PRIORITY_LOW: low
0x1: STM32_DMA_PRIORITY_MEDIUM: medium
0x2: STM32_DMA_PRIORITY_HIGH: high
0x3: STM32_DMA_PRIORITY_VERY_HIGH: very high
Example of dma usual combination for peripheral transfer
#define STM32_DMA_PERIPH_TX (STM32_DMA_MEMORY_TO_PERIPH | STM32_DMA_MEM_INC)
#define STM32_DMA_PERIPH_RX (STM32_DMA_PERIPH_TO_MEMORY | STM32_DMA_MEM_INC)
Example of dma node for stm32f103
dma1: dma-controller@40020400 {
compatible = "st,stm32-dma-v2bis";
...
dma-requests = <7>;
status = "disabled";
};
For the client part, example for stm32f103 on DMA1 instance
Tx using channel 3
Rx using channel 2
spi1 {
compatible = "st,stm32-spi";
dmas = <&dma1 3 (STM32_DMA_PERIPH_TX | STM32_DMA_PRIORITY_HIGH)>,
<&dma1 2 (STM32_DMA_PERIPH_RX | STM32_DMA_PRIORITY_HIGH)>;
dma-names = "tx", "rx";
};
Properties
Properties not inherited from the base binding file.
Name |
Type |
Details |
|---|---|---|
|
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Number of items to expect in a DMA specifier
This property is required. Constant value: |
|
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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.
|
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Number of DMA channels supported by the controller
|
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Number of DMA request signals supported by the controller.
|
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Memory address alignment requirement for DMA buffers used by the controller.
|
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Memory size alignment requirement for DMA buffers used by the controller.
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Minimal chunk of data possible to be copied by the controller.
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If the DMA controller V1 supports memory to memory transfer
|
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offset in the table of channels when mapping to a DMAMUX
for 1st dma instance, offset is 0,
for 2nd dma instance, offset is the nb of dma channels of the 1st dma,
for 3rd dma instance, offset is the nb of dma channels of the 2nd dma
plus the nb of dma channels of the 1st dma instance, etc.
|
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-dma-v2bis” compatible.
Name |
Type |
Details |
|---|---|---|
|
|
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.
|
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Automatically configure the device for runtime power management after the
init function runs.
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List of power states that will disable this device power.
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indicates the operational status of a device
Legal values: See Important properties for more information. |
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compatible strings
This property is required. See Important properties for more information. |
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register space
This property is required. See Important properties for more information. |
|
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name of each register space
|
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interrupts for device
This property is required. See Important properties for more information. |
|
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extended interrupt specifier for device
|
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name of each interrupt
|
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phandle to interrupt controller node
|
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Human readable string describing the device (used as device_get_binding() argument)
See Important properties for more information. This property is deprecated. |
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Clock gate information
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name of each clock
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number of address cells in reg property
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number of size cells in reg property
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DMA channels specifiers
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Provided names of DMA channel specifiers
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IO channels specifiers
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Provided names of IO channel specifiers
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mailbox / IPM channels specifiers
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Provided names of mailbox / IPM channel specifiers
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Power domain specifiers
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Provided names of power domain specifiers
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Number of cells in power-domains property
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Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
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Specifier cell names
dma cells: channel, channel-config