Usage Guidelines

How to Use
Obtaining a MIPI DSI Device Handle
Setting MIPI DSI Configuration Parameters
Sending/Receiving the Pointer to a Command
Releasing the MIPI DSI Device Handle

How to Use

Figure 1 shows the process of using a MIPI DSI device.

Figure 1 Process of using a MIPI DSI device

Obtaining a MIPI DSI Device Handle

Before performing MIPI DSI communication, obtain a MIPI DSI device handle by calling MipiDsiOpen. This function returns a MIPI DSI device handle with a specified channel ID.

DevHandle MipiDsiOpen(uint8_t id);

Table 1 Description of MipiDsiOpen

Parameter	Description
id	MIPI DSI channel ID.
Return Value	Description
NULL	Failed to obtain the MIPI DSI channel ID.
Device handle	MIPI DSI device handle with a specified channel ID, whose data type is DevHandle.

The following example shows how to obtain a MIPI DSI device handle with the channel ID 0:

DevHandle mipiDsiHandle = NULL;  /* Device handle */
chnId = 0;      /* MIPI DSI channel ID */

/* Obtain the MIPI DSI device handle based on a specified channel ID. */
mipiDsiHandle = MipiDsiOpen(chnId);
if (mipiDsiHandle == NULL) {
    HDF_LOGE("MipiDsiOpen: failed\n");
    return;
}

Setting MIPI DSI Configuration Parameters

Set MIPI DSI configuration parameters by calling the following function:

int32_t MipiDsiSetCfg(DevHandle handle, struct MipiCfg *cfg);

Table 2 Description of MipiDsiSetCfg

Parameter	Description
handle	MIPI DSI device handle
cfg	Pointer to MIPI DSI configuration parameters
Return Value	Description
0	Succeeded in setting MIPI DSI configuration parameters.
Negative value	Failed to set MIPI DSI configuration parameters.

int32_t ret;
struct MipiCfg cfg = {0};

/* Configuration parameters of the connected device are as follows: */
cfg.lane = DSI_4_LANES;
cfg.mode = DSI_CMD_MODE;
cfg.burstMode = VIDEO_NON_BURST_MODE_SYNC_EVENTS;
cfg.format = FORMAT_RGB_24_BIT;
cfg.pixelClk = 174;
cfg.phyDataRate = 384;
cfg.timingInfo.hsaPixels = 50;
cfg.timingInfo.hbpPixels = 55;
cfg.timingInfo.hlinePixels = 1200;
cfg.timingInfo.yResLines = 1800;
cfg.timingInfo.vbpLines = 33;
cfg.timingInfo.vsaLines = 76;
cfg.timingInfo.vfpLines = 120;
cfg.timingInfo.xResPixels = 1342;
/* Set MIPI DSI configuration parameters. */
ret = MipiDsiSetCfg(g_handle, &cfg);
if (ret != 0) {
    HDF_LOGE("%s: SetMipiCfg fail! ret=%d\n", __func__, ret);
    return -1;
}

Obtain MIPI DSI configuration parameters by calling the following function:

int32_t MipiDsiGetCfg(DevHandle handle, struct MipiCfg *cfg);

Table 3 Description of MipiDsiGetCfg

Parameter	Description
handle	MIPI DSI device handle
cfg	Pointer to MIPI DSI configuration parameters
Return Value	Description
0	Succeeded in obtaining MIPI DSI configuration parameters.
Negative value	Failed to obtain MIPI DSI configuration parameters.

int32_t ret;
struct MipiCfg cfg;
memset(&cfg, 0, sizeof(struct MipiCfg));
ret = MipiDsiGetCfg(g_handle, &cfg);
if (ret != HDF_SUCCESS) {
    HDF_LOGE("%s: GetMipiCfg fail!\n", __func__);
    return HDF_FAILURE;
}

Sending/Receiving the Pointer to a Command

Send the pointer to a specified command by calling the following function:

int32_t MipiDsiTx(PalHandle handle, struct DsiCmdDesc *cmd);

Table 4 Description of MipiDsiTx

Parameter	Description
handle	MIPI DSI device handle
cmd	Pointer to the command to be sent
Return Value	Description
0	Succeeded in sending the specified command.
Negative value	Failed to send the specified command.

int32_t ret;
struct DsiCmdDesc *cmd = OsalMemCalloc(sizeof(struct DsiCmdDesc));
if (cmd == NULL) {
    return HDF_FAILURE;
}
cmd->dtype = DTYPE_DCS_WRITE;
cmd->dlen = 1;
cmd->payload = OsalMemCalloc(sizeof(uint8_t));
if (cmd->payload == NULL) {
    HdfFree(cmd);
    return HDF_FAILURE;
}
*(cmd->payload) = DTYPE_GEN_LWRITE;
MipiDsiSetLpMode(mipiHandle);
ret = MipiDsiTx(mipiHandle, cmd);
MipiDsiSetHsMode(mipiHandle);
if (ret != HDF_SUCCESS) {
    HDF_LOGE("%s: PalMipiDsiTx fail! ret=%d\n", __func__, ret);
    HdfFree(cmd->payload);
    HdfFree(cmd);
    return HDF_FAILURE;
}
HdfFree(cmd->payload);
HdfFree(cmd);

Receive a specified command by calling the following function:

int32_t MipiDsiRx(DevHandle handle, struct DsiCmdDesc *cmd, uint32_t readLen, uint8_t *out);

Table 5 Description of MipiDsiRx

Parameter	Description
handle	MIPI DSI device handle
cmd	Pointer to the command to be received
readLen	Length of the data to read.
out	Pointer to the read data.
Return Value	Description
0	Succeeded in receiving the specified command.
Negative value	Failed to receive the specified command.

int32_t ret;
uint8_t readVal = 0;

struct DsiCmdDesc *cmdRead = OsalMemCalloc(sizeof(struct DsiCmdDesc));
if (cmdRead == NULL) {
    return HDF_FAILURE;
}
cmdRead->dtype = DTYPE_DCS_READ;
cmdRead->dlen = 1;
cmdRead->payload = OsalMemCalloc(sizeof(uint8_t));
if (cmdRead->payload == NULL) {
    HdfFree(cmdRead);
    return HDF_FAILURE;
}
*(cmdRead->payload) = DDIC_REG_STATUS;
MipiDsiSetLpMode(g_handle);
ret = MipiDsiRx(g_handle, cmdRead, sizeof(readVal), &readVal);
MipiDsiSetHsMode(g_handle);
if (ret != HDF_SUCCESS) {
    HDF_LOGE("%s: MipiDsiRx fail! ret=%d\n", __func__, ret);
    HdfFree(cmdRead->payload);
    HdfFree(cmdRead);
    return HDF_FAILURE;
}
HdfFree(cmdRead->payload);
HdfFree(cmdRead);

Releasing the MIPI DSI Device Handle

After the MIPI DSI communication, release the MIPI DSI device handle by calling the following function:

void MipiDsiClose(DevHandle handle);

This function releases the resources requested by MipiDsiOpen.

Table 6 Description of MipiDsiClose

Parameter	Description
handle	MIPI DSI device handle

MipiDsiClose(mipiHandle); /* Release the MIPI DSI device handle */

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Usage Guidelines

How to Use

Obtaining a MIPI DSI Device Handle

Setting MIPI DSI Configuration Parameters

Sending/Receiving the Pointer to a Command

Releasing the MIPI DSI Device Handle

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Usage Guidelines

How to Use

Obtaining a MIPI DSI Device Handle

Setting MIPI DSI Configuration Parameters

Sending/Receiving the Pointer to a Command

Releasing the MIPI DSI Device Handle

简介

发行版

贡献者

近期动态

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