# K230 DMA API Reference

## Overview

### Overview

GSDMA: DMA stands for Direct Memory Access, which means direct memory access, copying data from one address space to another address space, providing high-speed data transmission between memory and memory. GDMA, the full name of Graphic Direct Memory Access, is responsible for copying images in memory to another memory, and can also complete functions such as image rotation and mirroring. SDMA stands for System Direct Memory Access, which is responsible for copying data in memory to another memory, which is DMA in the traditional sense.

The software code provides various functions of GSDMA hardware to users in the form of API, helping users to quickly implement image transmission, rotation, mirroring, 2D functions and data transmission functions. At the same time, functions such as module status information statistics are implemented.

### Functional Description

Abstract the dma hardware into a device with eight channels, among which channel 0\~3 is the gdma channel and channel 4\~7 is the sdma channel.

#### gdma

Users use gdma to implement rotation and mirroring of images. The main calling process is as follows:

1. Configure dma device attributes;
1. Start the dma device. After calling this function, the driver will automatically apply for VB space as the data buffer of the destination address;
1. Configure gdma channel attributes;
1. Start gdma channel;
1. The user applies for VB space as a data buffer for source data in user mode, and calls kd_mpi_dma_send_frame to send the source address of the data to gdma;
1. The driver will transfer the data in the source address to the destination address data buffer applied for in step 2;
1. The user calls kd_mpi_dma_get_frame to obtain the data address in the destination address.

#### sdma

Users implement data migration through sdma. The main calling process is as follows:

1. Configure dma device attributes;
1. Start the dma device. After calling this function, the driver will automatically apply for VB space as the data buffer of the destination address;
1. Configure sdma channel attributes;
1. Start sdma channel;
1. The user applies for VB space in user mode as a data buffer for source data, and calls kd_mpi_dma_send_frame to send the source address of the data to sdma;
1. The driver will transfer the data in the source address to the destination address data buffer applied for in step 2;
1. The user calls kd_mpi_dma_get_frame to obtain the data address in the destination address.

## API Reference

### DMA uses

This function module provides the following APIs:

- [kd_mpi_dma_set_dev_attr](#kd_mpi_dma_set_dev_attr)
- [kd_mpi_dma_get_dev_attr](#kd_mpi_dma_get_dev_attr)
- [kd_mpi_dma_start_dev](#kd_mpi_dma_start_dev)
- [kd_mpi_dma_stop_dev](#kd_mpi_dma_stop_dev)
- [kd_mpi_dma_set_chn_attr](#kd_mpi_dma_set_chn_attr)
- [kd_mpi_dma_get_chn_attr](#kd_mpi_dma_get_chn_attr)
- [kd_mpi_dma_start_chn](#kd_mpi_dma_start_chn)
- [kd_mpi_dma_stop_chn](#kd_mpi_dma_stop_chn)
- [kd_mpi_dma_send_frame](#kd_mpi_dma_send_frame)
- [kd_mpi_dma_get_frame](#kd_mpi_dma_get_frame)
- [kd_mpi_dma_release_frame](#kd_mpi_dma_release_frame)

#### kd_mpi_dma_set_dev_attr

Description

Configure dma device properties

Syntax

k_s32 kd_mpi_dma_set_dev_attr(k_dma_dev_attr_t \*attr);

Parameters

| Parameter Name | Description | Input/Output |
|----------|---------------------------|-----------|
| attr | dma device attribute structure pointer. | Input |

Return Value

| Return Value | Description |
|--------|----------------------|
| 0 | Success |
| non-0 | Failure, please refer to the error code for its value. |

Chip differences

None.

Requirements

- Header File: mpi_dma_api.h
- Library File: libdma.a

Notes

None

Example

None

Related Topics

[k_dma_dev_attr_t](#k_dma_dev_attr_t)

#### kd_mpi_dma_get_dev_attr

Description

Get the configured dma device properties.

Syntax

k_s32 kd_mpi_dma_get_dev_attr(k_dma_dev_attr_t \*attr);

Parameters

| Parameter Name | Description | Input/Output |
|----------|------------------------|-----------|
| attr | dma device attribute structure pointer | Input |

Return Value

| Return Value | Description |
|--------|----------------------|
| 0 | Success |
| non-0 | Failure, please refer to the error code for its value. |

Chip differences

None

Requirements

- Header File: mpi_dma_api.h
- Library File: libdma.a

Notes

You need to configure the dma device properties before you can obtain the dma device properties.

Example

None

Related Topics

[k_dma_dev_attr_t](#k_dma_dev_attr_t)

#### kd_mpi_dma_start_dev

Description

Start the dma device.

Syntax

k_s32 kd_mpi_dma_start_dev();

Parameters

| Parameter Name | Description | Input/Output |
|----------|------|-----------|
| None | None | None |

Return Value

| Return Value | Description |
|--------|----------------------|
| 0 | Success |
| non-0 | Failure, please refer to the error code for its value. |

Chip differences

None

Requirements

- Header File: mpi_dma_api.h
- Library File: libdma.a

Notes

- You need to configure the dma device properties before you can call this function to start dma

Example

None

Related Topics

None

#### kd_mpi_dma_stop_dev

Description

Stop the dma device.

Syntax

kd_mpi_dma_stop_dev();

Parameters

| Parameter Name | Description | Input/Output |
|----------|------|-----------|
| None | None | None |

Return Value

| Return Value | Description |
|--------|----------------------|
| 0 | Success |
| non-0 | Failure, please refer to the error code for its value. |

Chip differences

None

Requirements

- Header File: mpi_dma_api.h
- Library File: libdma.a

Notes

- This function can be called to stop a dma device only after the dma device has been started.

Example

None

Related Topics

None

#### kd_mpi_dma_set_chn_attr

Description

Configure dma channel properties.

Syntax

k_s32 kd_mpi_dma_set_chn_attr(k_u8 chn_num, k_dma_chn_attr_u \*attr);

Parameters

| Parameter Name | Description | Input/Output |
|----------|----------------------------------------------------------------------------------------------------------------------------------|-----------|
| chn_num | Channel number | Input |
| attr | dma channel attributes, this parameter is a combination, you can choose to configure gdma channel attributes, you can also choose to configure sdma channel attributes. Channel 0\~3 is gdma, channel 4\~7 is sdma | Input |

Return Value

| Return Value | Description |
|--------|----------------------|
| 0 | Success |
| non-0 | Failure, please refer to the error code for its value. |

Chip differences

None

Requirements

- Header File: mpi_dma_api.h
- Library File: libdma.a

Notes

None

Example

None

Related Topics

[k_dma_chn_attr_u](#k_dma_chn_attr_u)

#### kd_mpi_dma_get_chn_attr

Description

Get the configured dma channel properties.

Syntax

k_s32 kd_mpi_dma_get_chn_attr(k_u8 chn_num, k_dma_chn_attr_u \*attr);

Parameters

| Parameter Name | Description | Input/Output |
|----------|----------------------------------------------------------------------------------------------------------------------------------|-----------|
| chn_num | Channel number | Input |
| attr | dma channel attribute, this parameter is a combination, you can choose to get the gdma channel attribute, you can also choose to get the sdma channel attribute. Channel 0\~3 is gdma, channel 4\~7 is sdma | Output |

Return Value

| Return Value | Description |
|--------|----------------------|
| 0 | Success |
| non-0 | Failure, please refer to the error code for its value. |

Chip differences

None

Requirements

- Header File: mpi_dma_api.h
- Library File: libdma.a

Notes

- You need to configure the dma channel attributes before you can obtain the dma channel attributes.

Example

None

Related Topics

[k_dma_chn_attr_u](#k_dma_chn_attr_u)

#### kd_mpi_dma_start_chn

Description

Start the dma channel.

Syntax

k_s32 kd_mpi_dma_start_chn(k_u8 chn_num);

Parameters

| Parameter Name | Description | Input/Output |
|----------|----------|-----------|
| chn_num | Channel number. | Input |

Return Value

| Return Value | Description |
|--------|----------------------|
| 0 | Success |
| non-0 | Failure, please refer to the error code for its value. |

Chip differences

None

Requirements

- Header File: mpi_dma_api.h
- Library File: libdma.a

Notes

- The DMA channel can be started only after configuring the DMA device and configuring the DMA channel properties.

Example

None

Related Topics

None

#### kd_mpi_dma_stop_chn

Description

pause dma channel

Syntax

k_s32 kd_mpi_dma_stop_chn(k_u8 chn_num);

Parameters

| Parameter Name | Description | Input/Output |
|----------|----------|-----------|
| chn_num | Channel number. | Input |

Return Value

| Return Value | Description |
|--------|----------------------|
| 0 | Success |
| non-0 | Failure, please refer to the error code for its value. |

Chip differences

None

Requirements

- Header File: mpi_dma_api.h
- Library File: libdma.a

Notes

- This function can be called to stop a dma channel only after the dma channel has been started.

Example

None

Related Topics

None

#### kd_mpi_dma_send_frame

Description

Send data from user space to the destination address.

Syntax

k_s32 kd_mpi_dma_send_frame(k_u8 chn_num, k_video_frame_info \*df_info, k_s32 millisec);

Parameters

| Parameter Name | Description | Input/Output |
|----------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|
| chn_num | Channel number. | Input |
| df_info | Address information for sending data. | Input |
| millisec | Waiting time. When this parameter is set to -1, it is blocking; when this parameter is set to 0, it is non-blocking; when this parameter is set to a value greater than 0, it will wait for the corresponding time until the data is successfully sent. If the data is not sent successfully after the timeout, failure is returned. | Input |

Return Value

| Return Value | Description |
|--------|----------------------|
| 0 | Success |
| non-0 | Failure, please refer to the error code for its value. |

Chip differences

None

Requirements

- Header File: mpi_dma_api.h
- Library File: libdma.a

Notes

None

Example

None

Related Topics

[k_video_frame_info](#k_video_frame_info)

#### kd_mpi_dma_get_frame

Description

Get the data after dma transfer.

Syntax

k_s32 kd_mpi_dma_get_frame(k_u8 chn_num, k_video_frame_info \*df_info, k_s32 millisec);

Parameters

| Parameter Name | Description | Input/Output |
|----------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|
| chn_num | Channel number. | Input |
| df_info | Get the address information of the data. | Output |
| millisec | Waiting time. When this parameter is set to -1, it is blocking; when this parameter is set to 0, it is non-blocking; when this parameter is set to a value greater than 0, it will wait for the corresponding time until the data is successfully obtained. If the data is not successfully sent after the timeout, a failure is returned. | Input |

Return Value

| Return Value | Description |
|--------|----------------------|
| 0 | Success |
| non-0 | Failure, please refer to the error code for its value. |

Chip differences

None

Requirements

- Header File: mpi_dma_api.h
- Library File: libdma.a

Notes

None

Example

None

Related Topics

[k_video_frame_info](#k_video_frame_info)

#### kd_mpi_dma_release_frame

Description

Release the acquired dma data.

Syntax

k_s32 kd_mpi_dma_release_frame(k_u8 chn_num, k_video_frame_info \*df_info);

Parameters

| Parameter Name | Description | Input/Output |
|----------|----------------|-----------|
| chn_num | Channel number. | Input |
| df_info | Data to be released. | Input |

Return Value

| Return Value | Description |
|--------|----------------------|
| 0 | Success |
| non-0 | Failure, please refer to the error code for its value. |

Chip differences

None

Requirements

- Header File: mpi_dma_api.h
- Library File: libdma.a

Notes

- In the current design, the dma output buffer is 3. If you obtain 3 frames of data without calling this function to release it, you cannot continue to input data. Therefore, users should obtain data and release it promptly after use.

Example

None

Related Topics

[k_video_frame_info](#k_video_frame_info)

## data type

### public data type

#### DMA_MAX_DEV_NUMS

Description

DMA maximum number of devices

definition

```c
#define DMA_MAX_DEV_NUMS (1)
```

Notes

None

Related Data Types and Interfaces

None

#### DMA_MAX_CHN_NUMS

Description

DMA maximum number of channels

definition

\#define DMA_MAX_CHN_NUMS (8)

Notes

None

Related Data Types and Interfaces

None

#### k_dma_mode_e

Description

Define dma working mode.

definition

```c
typedef enum
{
    DMA_BIND,
    DMA_UNBIND,
} k_dma_mode_e;
```

member

| member name | Description |
|----------|------------|
| BIND | Binding mode. |
| UNBIND | Unbound mode |

Notes

None

Related Data Types and Interfaces

[k_gdma_chn_attr_t](#k_gdma_chn_attr_t)
[k_sdma_chn_attr_t](#k_sdma_chn_attr_t)

#### k_dma_dev_attr_t

Description

Define dma device properties.

definition

```c
typedef struct
{
    k_u8 burst_len;
    k_u8 outstanding;
    k_bool ckg_bypass;
} k_dma_dev_attr_t;
```

member

| member name | Description |
|-------------|--------------------------|
| burst_len | Configure the burst length of dma |
| outstanding | Configure dma outstanding |
| ckg_bypass | Configure clock gate bypass |

Notes

None

Related Data Types and Interfaces

[kd_mpi_dma_set_dev_attr](#kd_mpi_dma_set_dev_attr)
[kd_mpi_dma_get_dev_attr](#kd_mpi_dma_get_dev_attr)

#### k_dma_chn_attr_u

Description

Define dma channel properties.

definition

```c
typedef union
{
    k_gdma_chn_attr_t gdma_attr;
    k_sdma_chn_attr_t sdma_attr;
} k_dma_chn_attr_u;
```

member

| member name | Description |
|------------|------------------------|
| gdma_attr | gdma channel properties |
| sdma_attr | sdma channel properties |
| ckg_bypass | Configure clock gate bypass |

Notes

None

Related Data Types and Interfaces

[k_gdma_chn_attr_t](#k_gdma_chn_attr_t)
[k_sdma_chn_attr_t](#k_sdma_chn_attr_t)
[kd_mpi_dma_set_chn_attr](#kd_mpi_dma_set_chn_attr)
[kd_mpi_dma_get_chn_attr](#kd_mpi_dma_get_chn_attr)

#### k_video_frame_info

Description

Define dma data address.

definition

```c
typedef struct
{
    k_video_frame v_frame;  /**< Video picture frame */
    k_u32 pool_id;          /**< VB pool ID */
    k_mod_id mod_id;        /**< Logical unit for generating video frames */
} k_video_frame_info;
```

member

| member name | Description |
|----------|--------------------------|
| v_frame | Timestamp, valid in binding mode. |
| pool_id | The pool id of the data vb pool. |
| mod_id | module id |

Notes

None

Related Data Types and Interfaces

[kd_mpi_dma_send_frame](#kd_mpi_dma_send_frame)
[kd_mpi_dma_get_frame](#kd_mpi_dma_get_frame)
[kd_mpi_dma_release_frame](#kd_mpi_dma_release_frame)

#### k_video_frame

Description

Define dma data address. Using the public data structure k_video_frame, only some of its members are used.

definition

```c
typedef struct
{
    k_u64 phys_addr[3];
    k_u64 virt_addr[3];
    k_u32 time_ref;
    k_u64 pts;
} k_video_frame;
```

member

| member name | Description |
|-----------|----------------------------------------------------------------------------------------------------------------------------------------------|
| phys_addr | The physical address of the image. If it is a single-channel image, you only need to configure the first physical address; if it is a dual-channel image, you only need to configure the first two physical addresses; if it is a three-channel image, you need to configure three physical addresses. |
| virt_addr | The virtual address of the image. If it is a single-channel image, you only need to configure the first virtual address; if it is a dual-channel image, you only need to configure the first two virtual addresses; if it is a three-channel image, you need to configure three virtual addresses. |
| time_ref | The frame number of transparent transmission is input by the previous stage in binding mode. |
| pts | The transparently transmitted timestamp is input by the previous stage in binding mode. |

Notes

None

Related Data Types and Interfaces

[kd_mpi_dma_send_frame](#kd_mpi_dma_send_frame)
[kd_mpi_dma_get_frame](#kd_mpi_dma_get_frame)

### gdma channel data type

This module has the following data types

- [GDMA_MAX_CHN_NUMS](#gdma_max_chn_nums)
- [k_gdma_rotation_e](#k_gdma_rotation_e)
- [k_pixel_format_dma_e](#k_pixel_format_dma_e)
- [k_gdma_chn_attr_t](#k_gdma_chn_attr_t)

#### GDMA_MAX_CHN_NUMS

Description

GDMA maximum number of channels

definition

```c
define GDMA_MAX_CHN_NUMS (4)
```

Notes

None

Related Data Types and Interfaces

None

#### k_gdma_rotation_e

Description

Define gdma channel rotation angle.

definition

```c
typedef enum
{
    DEGREE_0,       /**< Rotate 0 degrees */
    DEGREE_90,      /**< Rotate 90 degrees */
    DEGREE_180,     /**< Rotate 180 degrees */
    DEGREE_270,     /**< Rotate 270 degrees */
} k_gdma_rotation_e;
```

Notes

None

Related Data Types and Interfaces

[k_gdma_chn_attr_t](#k_gdma_chn_attr_t)

#### k_pixel_format_dma_e

Description

Defines gdma image format.

definition

```c
typedef enum
{
    DMA_PIXEL_FORMAT_RGB_444 = 0,
    DMA_PIXEL_FORMAT_RGB_555,
    DMA_PIXEL_FORMAT_RGB_565,
    DMA_PIXEL_FORMAT_RGB_888,

    DMA_PIXEL_FORMAT_BGR_444,
    DMA_PIXEL_FORMAT_BGR_555,
    DMA_PIXEL_FORMAT_BGR_565,
    DMA_PIXEL_FORMAT_BGR_888,

    DMA_PIXEL_FORMAT_ARGB_1555,
    DMA_PIXEL_FORMAT_ARGB_4444,
    DMA_PIXEL_FORMAT_ARGB_8565,
    DMA_PIXEL_FORMAT_ARGB_8888,

    DMA_PIXEL_FORMAT_ABGR_1555,
    DMA_PIXEL_FORMAT_ABGR_4444,
    DMA_PIXEL_FORMAT_ABGR_8565,
    DMA_PIXEL_FORMAT_ABGR_8888,

    DMA_PIXEL_FORMAT_YVU_PLANAR_420_8BIT,
    DMA_PIXEL_FORMAT_YVU_PLANAR_420_10BIT,
    DMA_PIXEL_FORMAT_YVU_PLANAR_420_16BIT,
    DMA_PIXEL_FORMAT_YVU_PLANAR_444_8BIT,
    DMA_PIXEL_FORMAT_YVU_PLANAR_444_10BIT,

    DMA_PIXEL_FORMAT_YUV_PLANAR_420_8BIT,
    DMA_PIXEL_FORMAT_YUV_PLANAR_420_10BIT,
    DMA_PIXEL_FORMAT_YUV_PLANAR_420_16BIT,

    DMA_PIXEL_FORMAT_YVU_SEMIPLANAR_420_8BIT,
    DMA_PIXEL_FORMAT_YVU_SEMIPLANAR_420_10BIT,
    DMA_PIXEL_FORMAT_YVU_SEMIPLANAR_420_16BIT,

    DMA_PIXEL_FORMAT_YUV_SEMIPLANAR_420_8BIT,
    DMA_PIXEL_FORMAT_YUV_SEMIPLANAR_420_10BIT,
    DMA_PIXEL_FORMAT_YUV_SEMIPLANAR_420_16BIT,

    DMA_PIXEL_FORMAT_YUV_400_8BIT,
    DMA_PIXEL_FORMAT_YUV_400_10BIT,
    DMA_PIXEL_FORMAT_YUV_400_12BIT,
    DMA_PIXEL_FORMAT_YUV_400_16BIT,

    DMA_PIXEL_FORMAT_YUV_PACKED_444_8BIT,
    DMA_PIXEL_FORMAT_YUV_PACKED_444_10BIT,

    /* SVP data format */
    DMA_PIXEL_FORMAT_BGR_888_PLANAR,
} k_pixel_format_dma_e;
```

#### k_gdma_chn_attr_t

Description

Define gdma channel properties.

definition

```c
typedef struct
{
    k_u8 buffer_num;
    k_gdma_rotation_e rotation;
    k_bool x_mirror;
    k_bool y_mirror;
    k_u16 width;
    k_u16 height;
    k_u16 src_stride[3];
    k_u16 dst_stride[3];
    k_dma_mode_e work_mode;
    k_pixel_format_dma_e pixel_format;
} k_gdma_chn_attr_t;
```

member

| member name | Description |
|--------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| buffer_num | Number of gdma channel buffers, at least 1. |
| rotation | gdma channel rotation angle. |
| x_mirror | Whether the gdma channel performs horizontal mirroring |
| y_mirror | Whether the gdma channel performs vertical mirroring |
| width | gdma channel width in pixels. |
| height | Gdma channel height in pixels. |
| src_stride | gdma source data stride. If the image format is single-channel mode, you only need to configure `src_stride[0]`; if the image format is dual-channel mode, you need to configure `src_stride[0]`, `src_stride[1]`; if the image format is three-channel mode, you need to configure `src_stride[0]`, `src_stride[1]`, `src_stride[2]`. |
| dst_stride | gdma destination data stride. If the image format is single-channel mode, you only need to configure `dst_stride[0]`; if the image format is dual-channel mode, you need to configure `dst_stride[0]`, `dst_stride[1]`; if the image format is three-channel mode, you need to configure `dst_stride[0]`, `dst_stride[1]`, `dst_stride[2]`. |
| work_mode | Working mode, you can choose binding mode or non-binding mode. |
| pixel_format | Image format. |

Notes

- None.

Related Data Types and Interfaces

- [kd_mpi_dma_set_chn_attr](#kd_mpi_dma_set_chn_attr)
- [kd_mpi_dma_get_chn_attr](#kd_mpi_dma_get_chn_attr)

### sdma channel data type

This module has the following data types

- [SDMA_MAX_CHN_NUMS](#sdma_max_chn_nums)
- [k_sdma_data_mode_e](#k_sdma_data_mode_e)
- [k_sdma_chn_attr_t](#k_sdma_chn_attr_t)

#### SDMA_MAX_CHN_NUMS

Description

SDMA maximum number of channels

definition

```c
#define SDMA_MAX_CHN_NUMS (4)
```

Notes

None

Related Data Types and Interfaces

None

#### k_sdma_data_mode_e

Description

Define the mode for sdma channel to transmit data

definition

```c
typedef enum
{
    DIMENSION1,
    DIMENSION2,
} k_sdma_data_mode_e;
```

member

| member name | Description |
|------------|-------------------|
| DIMENSION1 | one-dimensional dma transfer mode |
| DIMENSION1 | 2D DMA transfer mode |

Notes

None

Related Data Types and Interfaces

[k_sdma_chn_attr_t](#k_sdma_chn_attr_t)

#### k_sdma_chn_attr_t

Description

Define sdma channel properties.

definition

```c
typedef struct
{
    k_u8 buffer_num;
    k_u32 line_size;
    k_u16 line_num;
    k_u16 line_space;
    k_sdma_data_mode_e data_mode;
    k_dma_mode_e work_mode;
} k_sdma_chn_attr_t;
```

member

| member name | Description |
|------------|----------------------------------------------------------------------------|
| buffer_num | Number of sdma channel buffers, at least 1. |
| line_size | For 1d mode, it is the total length of transmitted data; for 2d mode, it is the length of a single line of data. |
| line_num | For 1d mode, this member is invalid; for 2d mode, it is the number of rows transferred. |
| line_space | For 1d mode, this member has no effect; for 2d mode, it is the space between rows. |
| data_mode | sdma data transmission mode, including 1d mode and 2d mode. |
| work_mode | Working mode, you can choose binding mode or non-binding mode. |

Notes

None

Related Data Types and Interfaces

[k_dma_chn_attr_u](#k_dma_chn_attr_u)

## error code

### dma error code

Table 41

| error code | Macro definition | Description |
|-------------|-------------------------|------------------------------|
| 0xa0148001 | K_ERR_DMA_INVALID_DEVID | Invalid device number |
| 0xa0148002 | K_ERR_DMA_INVALID_CHNID | Invalid channel number |
| 0xa0148003 | K_ERR_DMA_ILLEGAL_PARAM | Parameter error |
| 0xa0148004 | K_ERR_DMA_EXIST | DMA device already exists |
| 0xa0148005 | K_ERR_DMA_UNEXIST | DMA device does not exist |
| 0xa0148006 | K_ERR_DMA_NULL_PTR | Null pointer error |
| 0xa0148007 | K_ERR_DMA_NOT_CONFIG | DMA not configured yet |
| 0xa0148008 | K_ERR_DMA_NOT_SUPPORT | Unsupported features |
| 0xa0148009 | K_ERR_DMA_NOT_PERM | Operation not allowed |
| 0xa014800c | K_ERR_DMA_NOMEM | Failed to allocate memory, such as insufficient system memory |
| 0xa014800d | K_ERR_DMA_NOBUF | Not enough BUFF |
| 0xa014800e | K_ERR_DMA_BUF_EMPTY | BUFF is empty |
| 0xa014800f | K_ERR_DMA_BUF_FULL | BUFF is full |
| 0xa0148010 | K_ERR_DMA_NOTREADY | Device is not ready |
| 0xa0148011 | K_ERR_DMA_BADADDR | wrong address |
| 0xa0148012 | K_ERR_DMA_BUSY | DMA is in busy state |

## debugging information

### Overview

The debugging information uses the proc file system, which can reflect the current running status of the system in real time. The recorded information can be used for problem location and analysis.

File directory

/proc/

Document list

| File name | Description |
|-----------|-----------------------------|
| umap/dma | Record the current usage of dma module |

### System binding

#### System binding debugging information

debugging information

```shell
msh /\>cat /proc/umap/dma
-------------------------------dma dev attr info---------------------------------
DevId burst_len outstanding ckg_bypass
0 0 0 0

-------------------------------dma chn 0\~3 attr info-------------------------------
ChnId rotation x_mirror y_mirror width height work_mode
0 0 false false 0 0 BIND
1 0 false false 0 0 BIND
2 0 false false 0 0 BIND
3 0 false false 0 0 BIND

-------------------------------dma chn 4\~7 attr info-------------------------------
ChnId line_size line_num line_space data_mode work_mode
4 0 0 0 1 DIMENSION BIND
5 0 0 0 1 DIMENSION BIND
6 0 0 0 1 DIMENSION BIND
7 0 0 0 1 DIMENSION BIND
```

Debugging information analysis

Record the current usage of dma module

Equipment parameter description

| parameter | **describe** |
|-------------|------------------|
| DevId | Device number |
| burst_len | dma burst length |
| outstanding | dma outstanding |

gdma channel parameter description

| parameter | **describe** |
|-----------|------------------------|
| ChnId | Channel number |
| rotation | Degrees of rotation |
| x_mirror | Whether horizontal mirroring is performed |
| y_mirror | Whether vertical mirroring is performed |
| width | Image width in pixels |
| height | Image height in pixels |
| work_mode | working mode |

sdma channel parameter description

| parameter | **describe** |
|------------|----------------------------------------------------------------------------|
| ChnId | Channel number |
| line_size | For 1d mode, it is the total length of transmitted data; for 2d mode, it is the length of a single line of data. |
| ine_num | For 1d mode, this member is invalid; for 2d mode, it is the number of rows transferred. |
| line_space | For 1d mode, this member has no effect; for 2d mode, it is the space between rows. |
| data_mode | sdma data transmission mode, including 1d mode and 2d mode |
| work_mode | Working mode, you can choose binding mode or non-binding mode. |

## demo description

### Unbound mode demo

The non-binding mode demo is located in /bin/sample_dma.elf. After executing /bin/sample_dma.elf, it starts to run in a loop. Press e + Enter to end the run.

The demo mainly implements the following functions:

- Use channel 0 to transport images with a resolution of 1920\*1080, 8bit, YUV400 single channel, and output after gdma rotation 90 degrees;
- Use channel 1 to transport images with a resolution of 1280\*720, 8bit, YUV420 dual channels, and output after gdma rotation 180 degrees;
- Use channel 2 to transport images with a resolution of 1280\*720, 10bit, and YUV420 three channels. Gdma performs horizontal and vertical mirroring and outputs;
- Use channel 4 to transport data, sdma uses 1d mode to transport;
- Use channel 5 to carry data, sdma uses 2d mode to carry.

### Binding mode demo

The binding mode demo is located in /bin/sample_dma_bind.elf. After executing /bin/sample_dma_bind.elf, it starts to run in a loop. Press e + Enter to end the run.

The demo mainly implements the following functions:

- Use the vvi module as the simulation input of the gsdma front-end binding to implement the testing of the binding function;
- The two channels input images with a resolution of 640\*320, 8bit, and YUV400 single channel respectively. The gdma output is rotated by 90 degrees and 180 degrees respectively.