CSI2
- group CSI2
This API provides support for capturing images from an image sensor through the Camera Parallel Interface (CSI2) and processing them.
Typedefs
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typedef struct pi_csi2_conf pi_csi2_conf_t
Enums
Functions
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void pi_csi2_conf_init(struct pi_csi2_conf *conf)
Initialize a CSI2 configuration with default values.
The structure containing the configuration must be kept alive until the camera device is opened.
- Parameters:
conf – A pointer to the CSI2 configuration.
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int32_t pi_csi2_open(struct pi_device *device)
Open a CSI2 device.
This function must be called before the CSI2 device can be used. It configures the specified device that can then be used to refer to the opened device when calling other functions.
- Parameters:
device – A pointer to the structure describing the device. This structure muts be allocated by the caller and kept alive until the device is closed.
- Returns:
0 if it succeeded or -1 if it failed.
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void pi_csi2_close(struct pi_device *device)
Close an opened CSI2 device.
This function can be called to close an opened CSI2 device once it is not needed anymore in order to free all allocated resources. Once this function is called, the device is not accessible anymore and must be opened again before being used.
- Parameters:
device – A pointer to the structure describing the device.
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void pi_csi2_capture(struct pi_device *device, void *buffer, int32_t bufferlen)
Capture a sequence of samples.
Queue a buffer that will receive samples from the CSI2 interface. This function is synchronous and will block the caller until the specified amount of bytes is received. The buffer will receive samples only if the interface is started. Depending on the chip, there may be some restrictions on the memory which can be used. Check the chip-specific documentation for more details.
- Parameters:
device – A pointer to the structure describing the device.
buffer – The memory buffer where the captured samples will be transferred.
bufferlen – The size in bytes of the memory buffer.
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void pi_csi2_capture_async(struct pi_device *device, void *buffer, int32_t bufferlen, pi_evt_t *task)
Capture a sequence of samples asynchronously.
Queue a buffer that will receive samples from the CSI2 interface. This function is asynchronous and will not block the caller. It is possible to call it several times in order to queue several buffers. At a minimum 2 buffers should be queued to ensure that no data sampled is lost. This is also the most efficient way to retrieve data from the CSI2 device. You should always make sure that at least 2 buffers are always queued, by queuing a new one as soon as the current one is full. The buffer will receive samples only if the interface is started. A task must be specified in order to specify how the caller should be notified when the transfer is finished. Depending on the chip, there may be some restrictions on the memory which can be used. Check the chip-specific documentation for more details.
- Parameters:
device – A pointer to the structure describing the device.
buffer – The memory buffer where the captured samples will be transferred.
bufferlen – The size in bytes of the memory buffer.
task – The task used to notify the end of transfer. See the documentation of pi_task for more details.
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static inline void pi_csi2_control_start(struct pi_device *device)
Start capturing samples.
The samples arriving at the CSI2 interface are dropped until the interface is started by calling this function. Once started, the sampling will start at the next beginning of frame.
- Parameters:
device – A pointer to the structure describing the device.
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static inline void pi_csi2_control_stop(struct pi_device *device)
Stop capturing samples.
The samples arriving at the CSI2 interface are dropped after this call.
- Parameters:
device – A pointer to the structure describing the device.
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static inline void pi_csi2_set_lane(struct pi_device *device, uint8_t num)
Set lane number format.
This can be used configure the MIPI CSI2 lane number.
- Parameters:
device – A pointer to the structure describing the device.
num – Number of lanes, 0 - 1lane, 1 - 2lanes.
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static inline void pi_csi2_set_pixel_clk_div(struct pi_device *device, uint8_t pixel_div)
Set pixel clock divider.
This can be used configure the CSI2’s receiver’s pixel clock divder to match &* the frequency of MIPI CSI2 lane.
- Parameters:
device – A pointer to the structure describing the device.
pixel_div – Clock divider [0, 255].
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static inline void pi_csi2_set_apb_clk_div(struct pi_device *device, uint8_t apb_div)
Set APB clock divider.
This can be used configure the CSI2’s DPHY’s APB clock divder to configure &* the DPHY receiver.
- Parameters:
device – A pointer to the structure describing the device.
apb_div – Clock divider [0, 255].
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static inline void pi_csi2_set_virtual_channel(struct pi_device *device, uint8_t vc)
Set Virtual channel ID.
This can be used configure the CSI2’s DPHY’s virtual channel number, only support VC0 and VC1.
- Parameters:
device – A pointer to the structure describing the device.
vc – VC channel number, [0, 1]. If vc is 2, it means two outstanding streams
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struct pi_csi2_conf
- #include <csi2.h>
CSI2 device configuration structure.
This structure is used to pass the desired CSI2 configuration to the runtime when opening the device.
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typedef struct pi_csi2_conf pi_csi2_conf_t