Kernel-4.18.0-80.el8_ste-dma40

published: updated: Kernel_4.18.0-80.el8_内核文档
  • DMA40 DMA Controller

Required properties:

  • compatible: “stericsson,dma40”
  • reg: Address range of the DMAC registers
  • reg-names: Names of the above areas to use during resource look-up
  • interrupt: Should contain the DMAC interrupt number
  • #dma-cells: must be <3>
  • memcpy-channels: Channels to be used for memcpy

Optional properties:

  • dma-channels: Number of channels supported by hardware - if not present
      the driver will attempt to obtain the information from H/W
  • disabled-channels: Channels which can not be used

Example:

dma: dma-controller@801c0000 {
    compatible = "stericsson,db8500-dma40", "stericsson,dma40";
    reg = <0x801C0000 0x1000  0x40010000 0x800>;
    reg-names = "base", "lcpa";
    interrupt-parent = <&intc>;
    interrupts = <0 25 0x4>;

    #dma-cells = <2>;
    memcpy-channels  = <56 57 58 59 60>;
    disabled-channels  = <12>;
    dma-channels = <8>;
};

Clients
Required properties:

  • dmas: Comma separated list of dma channel requests
  • dma-names: Names of the aforementioned requested channels

Each dmas request consists of 4 cells:

  1. A phandle pointing to the DMA controller
  2. Device signal number, the signal line for single and burst requests
    connected from the device to the DMA40 engine
  3. The DMA request line number (only when ‘use fixed channel’ is set)
  4. A 32bit mask specifying; mode, direction and endianness
    [NB: This list will grow]
    0x00000001: Mode:
           Logical channel when unset
       Physical channel when set
    0x00000002: Direction:
           Memory to Device when unset
       Device to Memory when set
    0x00000004: Endianness:
           Little endian when unset
       Big endian when set
    0x00000008: Use fixed channel:
           Use automatic channel selection when unset
       Use DMA request line number when set
    0x00000010: Set channel as high priority:
           Normal priority when unset
       High priority when set

Existing signal numbers for the DB8500 ASIC. Unless specified, the signals are
bidirectional, i.e. the same for RX and TX operations:

0: SPI controller 0
1: SD/MMC controller 0 (unused)
2: SD/MMC controller 1 (unused)
3: SD/MMC controller 2 (unused)
4: I2C port 1
5: I2C port 3
6: I2C port 2
7: I2C port 4
8: Synchronous Serial Port SSP0
9: Synchronous Serial Port SSP1
10: Multi-Channel Display Engine MCDE RX
11: UART port 2
12: UART port 1
13: UART port 0
14: Multirate Serial Port MSP2
15: I2C port 0
16: USB OTG in/out endpoints 7 & 15
17: USB OTG in/out endpoints 6 & 14
18: USB OTG in/out endpoints 5 & 13
19: USB OTG in/out endpoints 4 & 12
20: SLIMbus or HSI channel 0
21: SLIMbus or HSI channel 1
22: SLIMbus or HSI channel 2
23: SLIMbus or HSI channel 3
24: Multimedia DSP SXA0
25: Multimedia DSP SXA1
26: Multimedia DSP SXA2
27: Multimedia DSP SXA3
28: SD/MM controller 2
29: SD/MM controller 0
30: MSP port 1 on DB8500 v1, MSP port 3 on DB8500 v2
31: MSP port 0 or SLIMbus channel 0
32: SD/MM controller 1
33: SPI controller 2
34: i2c3 RX2 TX2
35: SPI controller 1
36: USB OTG in/out endpoints 3 & 11
37: USB OTG in/out endpoints 2 & 10
38: USB OTG in/out endpoints 1 & 9
39: USB OTG in/out endpoints 8
40: SPI controller 3
41: SD/MM controller 3
42: SD/MM controller 4
43: SD/MM controller 5
44: Multimedia DSP SXA4
45: Multimedia DSP SXA5
46: SLIMbus channel 8 or Multimedia DSP SXA6
47: SLIMbus channel 9 or Multimedia DSP SXA7
48: Crypto Accelerator 1
49: Crypto Accelerator 1 TX or Hash Accelerator 1 TX
50: Hash Accelerator 1 TX
51: memcpy TX (to be used by the DMA driver for memcpy operations)
52: SLIMbus or HSI channel 4
53: SLIMbus or HSI channel 5
54: SLIMbus or HSI channel 6
55: SLIMbus or HSI channel 7
56: memcpy (to be used by the DMA driver for memcpy operations)
57: memcpy (to be used by the DMA driver for memcpy operations)
58: memcpy (to be used by the DMA driver for memcpy operations)
59: memcpy (to be used by the DMA driver for memcpy operations)
60: memcpy (to be used by the DMA driver for memcpy operations)
61: Crypto Accelerator 0
62: Crypto Accelerator 0 TX or Hash Accelerator 0 TX
63: Hash Accelerator 0 TX

Example:

uart@80120000 {
    compatible = "arm,pl011", "arm,primecell";
    reg = <0x80120000 0x1000>;
    interrupts = <0 11 0x4>;

    dmas = <&dma 13 0 0x2>, /* Logical - DevToMem */
           <&dma 13 0 0x0>; /* Logical - MemToDev */
    dma-names = "rx", "rx";

};

oosTech by Sam Lee