blob: 20870f5c14dd0a68c54ad3566f8fc75a47777bb0 [file] [log] [blame]
# SPDX-License-Identifier: GPL-2.0-only
%YAML 1.2
---
$id: http://devicetree.org/schemas/dma/snps,dma-spear1340.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Synopsys Designware DMA Controller
maintainers:
- Viresh Kumar <vireshk@kernel.org>
- Andy Shevchenko <andriy.shevchenko@linux.intel.com>
allOf:
- $ref: "dma-controller.yaml#"
properties:
compatible:
const: snps,dma-spear1340
"#dma-cells":
const: 3
description: |
First cell is a phandle pointing to the DMA controller. Second one is
the DMA request line number. Third cell is the memory master identifier
for transfers on dynamically allocated channel. Fourth cell is the
peripheral master identifier for transfers on an allocated channel.
reg:
maxItems: 1
interrupts:
maxItems: 1
clocks:
maxItems: 1
clock-names:
description: AHB interface reference clock.
const: hclk
dma-channels:
description: |
Number of DMA channels supported by the controller. In case if
not specified the driver will try to auto-detect this and
the rest of the optional parameters.
minimum: 1
maximum: 8
dma-requests:
minimum: 1
maximum: 16
dma-masters:
$ref: /schemas/types.yaml#definitions/uint32
description: |
Number of DMA masters supported by the controller. In case if
not specified the driver will try to auto-detect this and
the rest of the optional parameters.
minimum: 1
maximum: 4
chan_allocation_order:
$ref: /schemas/types.yaml#definitions/uint32
description: |
DMA channels allocation order specifier. Zero means ascending order
(first free allocated), while one - descending (last free allocated).
default: 0
enum: [0, 1]
chan_priority:
$ref: /schemas/types.yaml#definitions/uint32
description: |
DMA channels priority order. Zero means ascending channels priority
so the very first channel has the highest priority. While 1 means
descending priority (the last channel has the highest priority).
default: 0
enum: [0, 1]
block_size:
$ref: /schemas/types.yaml#definitions/uint32
description: Maximum block size supported by the DMA controller.
enum: [3, 7, 15, 31, 63, 127, 255, 511, 1023, 2047, 4095]
data-width:
$ref: /schemas/types.yaml#/definitions/uint32-array
description: Data bus width per each DMA master in bytes.
items:
maxItems: 4
items:
enum: [4, 8, 16, 32]
data_width:
$ref: /schemas/types.yaml#/definitions/uint32-array
deprecated: true
description: |
Data bus width per each DMA master in (2^n * 8) bits. This property is
deprecated. It' usage is discouraged in favor of data-width one. Moreover
the property incorrectly permits to define data-bus width of 8 and 16
bits, which is impossible in accordance with DW DMAC IP-core data book.
items:
maxItems: 4
items:
enum:
- 0 # 8 bits
- 1 # 16 bits
- 2 # 32 bits
- 3 # 64 bits
- 4 # 128 bits
- 5 # 256 bits
default: 0
multi-block:
$ref: /schemas/types.yaml#/definitions/uint32-array
description: |
LLP-based multi-block transfer supported by hardware per
each DMA channel.
items:
maxItems: 8
items:
enum: [0, 1]
default: 1
snps,max-burst-len:
$ref: /schemas/types.yaml#/definitions/uint32-array
description: |
Maximum length of the burst transactions supported by the controller.
This property defines the upper limit of the run-time burst setting
(CTLx.SRC_MSIZE/CTLx.DST_MSIZE fields) so the allowed burst length
will be from 1 to max-burst-len words. It's an array property with one
cell per channel in the units determined by the value set in the
CTLx.SRC_TR_WIDTH/CTLx.DST_TR_WIDTH fields (data width).
items:
maxItems: 8
items:
enum: [4, 8, 16, 32, 64, 128, 256]
default: 256
snps,dma-protection-control:
$ref: /schemas/types.yaml#definitions/uint32
description: |
Bits one-to-one passed to the AHB HPROT[3:1] bus. Each bit setting
indicates the following features: bit 0 - privileged mode,
bit 1 - DMA is bufferable, bit 2 - DMA is cacheable.
default: 0
minimum: 0
maximum: 7
unevaluatedProperties: false
required:
- compatible
- "#dma-cells"
- reg
- interrupts
examples:
- |
dma-controller@fc000000 {
compatible = "snps,dma-spear1340";
reg = <0xfc000000 0x1000>;
interrupt-parent = <&vic1>;
interrupts = <12>;
dma-channels = <8>;
dma-requests = <16>;
dma-masters = <4>;
#dma-cells = <3>;
chan_allocation_order = <1>;
chan_priority = <1>;
block_size = <0xfff>;
data-width = <8 8>;
multi-block = <0 0 0 0 0 0 0 0>;
snps,max-burst-len = <16 16 4 4 4 4 4 4>;
};
...