X-Git-Url: http://git.rot13.org/?p=goodfet;a=blobdiff_plain;f=firmware%2Fapps%2Fi2c%2Fi2c.c;h=e58b266dc96f438a57ca85527a1556572c7459ce;hp=1f92b9e92b478d7f0b5456e1b8c5647677a3c72c;hb=6373a97ac3426c9d9966cf6a08286ecd13cc2ced;hpb=aa1ad64b8f1a87590c9a94d32a1561bca33e843c diff --git a/firmware/apps/i2c/i2c.c b/firmware/apps/i2c/i2c.c index 1f92b9e..e58b266 100644 --- a/firmware/apps/i2c/i2c.c +++ b/firmware/apps/i2c/i2c.c @@ -1,5 +1,8 @@ -//GoodFET I2C Master Application -//Handles basic I/O +/*! \file i2c.c + \author Travis Goodspeed + \brief I2C Master +*/ + //Higher level left to client application. @@ -8,28 +11,73 @@ #include "platform.h" #include "command.h" +#include "i2c.h" #include -#include +#include #include //Pins and I/O -#define SS BIT3 -#define SDA BIT2 -#define SCL BIT3 +#include + +//! Handles an i2c command. +void i2c_handle_fn( uint8_t const app, + uint8_t const verb, + uint32_t const len); + +// define the i2c app's app_t +app_t const i2c_app = { + + /* app number */ + I2C_APP, + + /* handle fn */ + i2c_handle_fn, + + /* name */ + "I2C", + + /* desc */ + "\tThe I2C app implements the i2c bus protocol thus\n" + "\tturning your GoodFET into a USB-to-i2c adapter.\n" +}; + +#define I2CDELAY(x) delay(x<<4) + + +//2xx only, need 1xx compat code +#if (board == tilaunchpad) +// P3.1 SDA +// P3.3 SCL +#define SDA (1<<1) +#define SCL (1<<3) + +#define CLRSDA P3OUT&=~SDA +#define SETSDA P3OUT|=SDA +#define CLRSCL P3OUT&=~SCL +#define SETSCL P3OUT|=SCL + +#define READSDA (P3IN&SDA?1:0) +#define SDAINPUT P3DIR&=~SDA +#define SDAOUTPUT P3DIR|=SDA +#define SCLINPUT P3DIR&=~SCL +#define SCLOUTPUT P3DIR|=SCL +#define SETBOTH P3OUT|=(SDA|SCL) + +#else -#define I2CDELAY(x) delay(x) +#define SDA TDI +#define SCL TDO -//Bits are cleared by output of low. -//Bits are set but input and pull-up resistor. -#define SETSDA P5DIR&=~SDA -#define CLRSDA P5DIR|=SDA -#define SETSCL P5DIR&=~SCL -#define CLRSCL P5DIR|=SCL +#define CLRSDA P5OUT&=~SDA +#define SETSDA P5OUT|=SDA +#define CLRSCL P5OUT&=~SCL +#define SETSCL P5OUT|=SCL #define READSDA (P5IN&SDA?1:0) -#define SETBOTH P5DIR&=~(SDA|SCL) +#define SETBOTH P5OUT|=(SDA|SCL) +#endif #define I2C_DATA_HI() SETSDA #define I2C_DATA_LO() CLRSDA @@ -37,6 +85,39 @@ #define I2C_CLOCK_HI() SETSCL #define I2C_CLOCK_LO() CLRSCL +//#warning "Using internal resistors. Won't work on 161x devices." + +//! Inits bitbanging port, must be called before using the functions below +void I2C_Init() +{ + + //Clear SDA and SCL. + //Direction, not value, is used to set the value. + //(Pull-up or 0.) + +#if (platform == tilaunchpad) + SDAOUTPUT; + SCLOUTPUT; +#else + P5DIR|=(SDA|SCL); +#endif + //P5REN|=SDA|SCL; + + + I2C_CLOCK_HI(); + I2C_DATA_HI(); + + I2CDELAY(1); +} + +#if (platform == tilaunchpad) +void I2C_Exit() +{ + SDAINPUT; + SCLINPUT; +} +#endif + //! Write an I2C bit. void I2C_WriteBit( unsigned char c ) { @@ -63,29 +144,18 @@ unsigned char I2C_ReadBit() I2C_DATA_HI(); I2C_CLOCK_HI(); + SDAINPUT; I2CDELAY(1); - + unsigned char c = READSDA; I2C_CLOCK_LO(); I2CDELAY(1); + SDAOUTPUT; return c; } -//! Inits bitbanging port, must be called before using the functions below -void I2C_Init() -{ - //Clear SDA and SCL. - //Direction, not value, is used to set the value. - //(Pull-up or 0.) - P5OUT&=~(SDA|SCL); - - I2C_CLOCK_HI(); - I2C_DATA_HI(); - - I2CDELAY(1); -} //! Send a START Condition void I2C_Start() @@ -116,7 +186,7 @@ unsigned char I2C_Write( unsigned char c ) { char i; for (i=0;i<8;i++){ - I2C_WriteBit( c & 128 ); + I2C_WriteBit( c & 0x80 ); c<<=1; } @@ -146,41 +216,48 @@ unsigned char I2C_Read( unsigned char ack ) } -//! Handles a monitor command. -void i2chandle(unsigned char app, - unsigned char verb, - unsigned char len){ - unsigned char i; - switch(verb){ - - case PEEK: - break; - case POKE: - break; - - case READ: - if(len>0) //optional parameter of length - len=cmddata[0]; - if(len==0) //default value of 1 - len=1; - for(i=0;i 0) //optional parameter of length + l=cmddata[0]; + if(!l) //default value of 1 + l=1; + for(i = 0; i < l; i++) + cmddata[i]=I2C_Read(1); //Always acknowledge + txdata(app,verb,l); + break; + case WRITE: + cmddata[0]=0; + for(i=0;i