NetSilicon & Digi Confidential NET+OS 6.1 Training 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential I2C device topics Introduction I2C APIs I2C examples 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential I2C device basic Simple 4-wire device. Multiple I2C devices can be connected to the same I2C bus. We support two types (all) I2C devices – I2C Master and I2C Slave. 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Performance We support 100Kbits/sec or 400Kbits/sec. Support 7 & 10 bit addressing Dedicated I/O. No change to the gpio.h 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential IC2 Master Interface 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential I2C Slave 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential 7bit addressing format Slave Address Data(8Bit) RW A S 1. Received of slave side 2. Transmitted of slave side 1 P S = Start A = ACK P = STOP / Repeat Start From master to slave From slave to master 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential 10bit addressing format Address Upper Address Lower RW A Data(8Bit) S 1. Received of slave side 2. Transmitted of slave side 1 P S = Start A = ACK P = STOP / Repeat Start From master to slave From slave to master 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Device Open() Calls i2c_dev_open() Example i2cPort = open("/i2c/0",I2C_SLAVE); or i2cPort = open("/i2c/0",I2C_MASTER); I2C device channel: /i2c/0 I2C device mode: I2C_MASTER, or I2C_SLAVE. 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Device close() Calls i2c_dev_close() Closes the I2C channel. Example: ret = close(fd); 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Device Read() Calls i2c_dev_read(). int i2c_dev_read(int channel, void * i2cMsg, int notUsed, int * notUsed1); Note: i2cMsg is pointer to the i2cMsg type. The i2cMeg will be returned by a read callback function in an ISR. DO NOT access it before it is returned. 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Device Write() Calls i2c_dev_write(). int i2c_dev_write(int channel, void * i2cMsg, int notUsed, int * notUsed1) The i2cMsg will be returned by a write callback function in an ISR context. DO NOT access the message before it is returned. 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Device Ioctl() Calls i2c_dev_ioctl() Important flags: I2C_SET_READ_CALLBACK_FUNC I2C_SET_WRITE_CALLBACK_FUNC I2C_SET_CLOCK_SPEED I2C_SET_GCA_IRQ_ENABLE I2C_FLUSH_BUFFER 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Other APIs void MCI2cBuildMsg(MC_I2C_MESSAGE_TYPE* i2cMsg, char* buf, unsigned long bufLength, unsigned char addr); 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential I2C Specific…. I2C driver is interrupt driven and the I2C interrupt is part of the BBUS interrupt. After we install the I2C interrupt function, on receiving every data byte and I2C commannd, we will receive an interrupt generated by the I2C IP. The MCI2cInterrupt() function will then be called by the ISR handler. Based on the state of the current I2C bus and whether the Mercury is acting as an I2C Master or Slave, the appropriate function will be called. Please refer to the I2C Master or Slave State machine for ISR handling details. A semaphore is used to keep multiple I2C port from opening at the same time. A Event flag is created in the application example; but it is up to the application to decide whether to use it or not. The same applies to the Event flag in the nausbdevapp example as well. 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Example Typical User application A typical open function call is fd = open(“i2c/0”, I2C_MASTER); Or fd = open(“i2c/0”, I2C_SLAVE); A typical close function call is Ret = close(fd); 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Read() Example Typical usage: The third parameter is ignored. Ret=Read(fd, i2cMsg, 0x0); If (ret == -1) printf(“ read failed.\n”); 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Write() example Typical usage: The third parameter is ignored. Ret=write(fd, i2cMsg, 0x0); If (ret == -1) printf(“ write failed.\n”); 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential I2C message defination typedef struct _MESSAGE_TYPE { char * buffer; unsigned short address; unsigned long bufLength; /* size of the buffer */ unsigned long availableDataLen; MC_I2C_BUFFER_STATE state; } MC_I2C_MESSAGE_TYPE; 11/15/2018 NetSilicon & Digi Confidential

Typical write Callback function void writeCallBackFunc(MC_I2C_MESSAGE_TYPE * ptrData) { if (ptrData->state != I2C_INIT) tx_event_flags_set(&i2cEvent,I2C_WRITE_EVENT_FLAG, TX_OR); /* free(ptrData); */ } return; 11/15/2018 NetSilicon & Digi Confidential

Typical read callback function void readCallBackFunc(MC_I2C_MESSAGE_TYPE * ptrData) { if (ptrData->state != I2C_INIT) tx_event_flags_set(&i2cEvent,I2C_READ_EVENT_FLAG, TX_OR); /* free(ptrData); */ } return; 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Example application MCI2cBuildMsg(i2cMsg, ptrTemp, 26, 0x60); ret = write(i2cPort, i2cMsg, 0); MCInstallIsr (I2C_INTERRUPT, (MC_ISR_HANDLER) MCI2cInterrupt, (void *) 0, 0); while( 1 /* mySleepCount < 6 */) { ret = tx_event_flags_get(&i2cEvent, I2C_WRITE_EVENT_FLAG|I2C_READ_EVENT_FLAG, TX_OR_CLEAR, &actualEvent, TX_WAIT_FOREVER); …… 11/15/2018 NetSilicon & Digi Confidential

NetSilicon & Digi Confidential Important files Driver: Src/bsp/devices/i2c/* Example: Src/examples/nai2capp/itc_test.c 11/15/2018 NetSilicon & Digi Confidential