在一些特殊的使用场合，有需要使用AWR1642对PMIC的输出电压进行调节，或是读取PMIC 内部的工作状态，此时需要I2C接口对PMIC进行读写操作，本文介绍了在现有的mmWave SDK demo中集成I2C接口驱动所需的步骤及操作。 本文的测试环境如下： 1. 在mmWave SDK demo中增加I2C驱动代码 第一步是添加代码以包含和初始化I2C驱动程序。从I2C接口发送和接收均需要此驱动程序的支持，以下是在mss_main.c中添加的初始化I2C驱动程序的C代码。此测试代码可以复制到现有工程中。I2C驱动操作步骤为：GPIO初始化，I2C驱动初始化，配置I2C改写PMIC(LP87524B)寄存器以实现PMIC输出电压调节。 #include <ti/drivers/i2c/i2c.h>
static int32_t I2C_GPIOInit(void) { #if (defined(SOC_XWR14XX)) /* Setup the PINMUX to bring out the XWR14xx I2C pins */ Pinmux_Set_OverrideCtrl(SOC_XWR14XX_PINR3_PADAH, PINMUX_OUTEN_RETAIN_HW_CTRL, PINMUX_INPEN_RETAIN_HW_CTRL); Pinmux_Set_FuncSel(SOC_XWR14XX_PINR3_PADAH, SOC_XWR14XX_PINR3_PADAH_I2C_SDA); Pinmux_Set_OverrideCtrl(SOC_XWR14XX_PINP4_PADAI, PINMUX_OUTEN_RETAIN_HW_CTRL, PINMUX_INPEN_RETAIN_HW_CTRL); Pinmux_Set_FuncSel(SOC_XWR14XX_PINP4_PADAI, SOC_XWR14XX_PINP4_PADAI_I2C_SCL); #else /* Setup the PINMUX to bring out the XWR16xx I2C pins */ Pinmux_Set_OverrideCtrl(SOC_XWR16XX_PINF13_PADAH, PINMUX_OUTEN_RETAIN_HW_CTRL, PINMUX_INPEN_RETAIN_HW_CTRL); Pinmux_Set_FuncSel(SOC_XWR16XX_PINF13_PADAH, SOC_XWR16XX_PINF13_PADAH_I2C_SDA);
Pinmux_Set_OverrideCtrl(SOC_XWR16XX_PING14_PADAI, PINMUX_OUTEN_RETAIN_HW_CTRL, PINMUX_INPEN_RETAIN_HW_CTRL); Pinmux_Set_FuncSel(SOC_XWR16XX_PING14_PADAI, SOC_XWR16XX_PING14_PADAI_I2C_SCL); #endif return 0; } static int32_t I2C_Communication_Test() { bool retVal = false; int32_t errCode = 0; uint32_t arg; uint8_t rxData[16]; uint8_t txData[16]; I2C_Transaction i2cTransaction; I2C_Handle i2cHandle; I2C_Params i2cParams;
/* Reset the transmit and receive buffer */ memset(&rxData, 0, sizeof (rxData));
/* Initializa the I2C driver */ I2C_init();
/* Initialize the I2C driver default parameters */ I2C_Params_init(&i2cParams);
i2cParams.transferMode = I2C_MODE_BLOCKING; i2cParams.bitRate = I2C_100kHz;
/* Open the I2C driver */ i2cHandle = I2C_open(0, &i2cParams);
if (i2cHandle == NULL) { System_printf ("Error: I2C Driver Open failed\n"); return -1; }
/* Configure the I2C device in I2C_CMD_ADDR_MODE mode */ arg = 0;//arg set to 0, and the I2C addr mode is 7-bit. errCode = I2C_control (i2cHandle, I2C_CMD_ADDR_MODE, (void* )&arg); if (errCode < 0) { System_printf ("Error: I2C control Set I2C_CMD_ADDR_MODE failed [Error code %d]\n", errCode); return -1; }
//read the LP87524B buck3 output voltage register txData[0] = 0x10; i2cTransaction.slaveAddress = 0x60;//LP87524B/J-Q1 Device Address = 0x60 i2cTransaction.writeBuf = txData; i2cTransaction.writeCount = 1; i2cTransaction.readBuf = rxData; i2cTransaction.readCount = 1; retVal = I2C_transfer(i2cHandle, &i2cTransaction); if (retVal == false) { System_printf ("Error: I2C Transfer failed\n"); return -1; } System_printf("I2C_READ: addr=0x%x, Val=0x%x\n",txData[0],rxData[0]); //write the LP87524B buck3 output voltage = 2.0V txData[0] = 0x10; txData[1] = 0xbb;//default=0xca,2.3V,0xb1=1.8V, 0xbb=2.0V i2cTransaction.slaveAddress = 0x60;//LP87524B/J-Q1 Device Address = 0x60 i2cTransaction.writeBuf = txData; i2cTransaction.writeCount = 2; i2cTransaction.readBuf = rxData; i2cTransaction.readCount = 0; retVal = I2C_transfer(i2cHandle, &i2cTransaction); if (retVal == false) { System_printf ("Error: I2C Transfer failed\n"); return -1; } System_printf("I2C_Write: LP87524B buck3 = 2.0V Done\n");
//read the LP87524B buck3 output voltage register txData[0] = 0x10; i2cTransaction.slaveAddress = 0x60;//LP87524B/J-Q1 Device Address = 0x60 i2cTransaction.writeBuf = txData; i2cTransaction.writeCount = 1; i2cTransaction.readBuf = rxData; i2cTransaction.readCount = 1; retVal = I2C_transfer(i2cHandle, &i2cTransaction); if (retVal == false) { System_printf ("Error: I2C Transfer failed\n"); return -1; } System_printf("I2C_READ: addr=0x%x, Val=0x%x\r\n",txData[0],rxData[0]);
//write the LP87524B buck2 output voltage = 1.5V txData[0] = 0x0e; txData[1] = 0Xa2;//default=0xb1,1.8V, 0x4d=1V 0xa2=1.5V i2cTransaction.slaveAddress = 0x60;//LP87524B/J-Q1 Device Address = 0x60 i2cTransaction.writeBuf = txData; i2cTransaction.writeCount = 2; i2cTransaction.readBuf = rxData; i2cTransaction.readCount = 0; retVal = I2C_transfer(i2cHandle, &i2cTransaction); if (retVal == false) { System_printf ("Error: I2C Transfer failed\n"); return -1; } System_printf("I2C_Write: LP87524B buck2 = 1.5V Done\n"); if (retVal == false) { System_printf ("Error: I2C combined Transfer to Slave failed\n"); return -1; } /* Close I2C driver */ I2C_close(i2cHandle); return 0; }
//Call these function in void MmwDemo_mssInitTask(UArg arg0, UArg arg1) errCode = I2C_GPIOInit(); if (errCode == -1) System_printf("I2C_GPIOInit Error\r\n"); errCode = I2C_Communication_Test(); if (errCode == -1) System_printf("I2C_Communication_Test Error\n"); else System_printf("I2C_Communication_Test Done\n"); 2. 将工程链接到I2C驱动库 最后一步是通过链接I2C驱动程序来构建可执行文件。 如果使用CCS项目，可以将I2C驱动程序添加到项目的链接器属性中，如图1所示。 图1. CCS Project Linker Properties
如果使用makefile编译工程，执行相同的程序。 ################################################################################### # Additional libraries which are required to build the DEMO: ################################################################################### MSS_MMW_DEMO_STD_LIBS = $(R4F_COMMON_STD_LIB) \ -llibpinmux_$(MMWAVE_SDK_DEVICE_TYPE).$(R4F_LIB_EXT) \ -llibdma_$(MMWAVE_SDK_DEVICE_TYPE).$(R4F_LIB_EXT) \ -llibcrc_$(MMWAVE_SDK_DEVICE_TYPE).$(R4F_LIB_EXT) \ -llibuart_$(MMWAVE_SDK_DEVICE_TYPE).$(R4F_LIB_EXT) \ -llibgpio_$(MMWAVE_SDK_DEVICE_TYPE).$(R4F_LIB_EXT) \ -llibmailbox_$(MMWAVE_SDK_DEVICE_TYPE).$(R4F_LIB_EXT) \ -llibmmwavelink_$(MMWAVE_SDK_DEVICE_TYPE).$(R4F_LIB_EXT) \ -llibmmwave_$(MMWAVE_SDK_DEVICE_TYPE).$(R4F_LIB_EXT) \ -llibcli_$(MMWAVE_SDK_DEVICE_TYPE).$(R4F_LIB_EXT) \ -llibi2c_$(MMWAVE_SDK_DEVICE_TYPE).$(R4F_LIB_EXT) MSS_MMW_DEMO_LOC_LIBS = $(R4F_COMMON_LOC_LIB) \ -i$(MMWAVE_SDK_INSTALL_PATH)/ti/drivers/pinmux/lib \ -i$(MMWAVE_SDK_INSTALL_PATH)/ti/drivers/uart/lib \ -i$(MMWAVE_SDK_INSTALL_PATH)/ti/drivers/dma/lib \ -i$(MMWAVE_SDK_INSTALL_PATH)/ti/drivers/crc/lib \ -i$(MMWAVE_SDK_INSTALL_PATH)/ti/drivers/gpio/lib \ -i$(MMWAVE_SDK_INSTALL_PATH)/ti/drivers/mailbox/lib \ -i$(MMWAVE_SDK_INSTALL_PATH)/ti/control/mmwavelink/lib \ -i$(MMWAVE_SDK_INSTALL_PATH)/ti/control/mmwave/lib \ -i$(MMWAVE_SDK_INSTALL_PATH)/ti/utils/cli/lib \ -i$(MMWAVE_SDK_INSTALL_PATH)/ti/utils/i2c/lib
3. 运行测试例程 运行测试程序后，CCS控制台输出打印信息如下，使用万用表测量LP87524输出电压即为设置的电压，I2C驱动添加成功。 ********************************************** Debug: Launching the Millimeter Wave Demo ********************************************** I2C_READ: addr=0x10, Val=0xca I2C_Write: LP87524B buck3 = 2.0V Done I2C_READ: addr=0x10, Val=0xbb I2C_Write: LP87524B buck2 = 1.5V Done I2C_Communication_Test Done
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