Hi,
I'm trying to rationalize some very common I2C code and came across the following:
Every controller except cpu/mpc8xx implements functions like this:
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uchar i2c_reg_read(uchar i2c_addr, uchar reg) { uchar buf;
i2c_read(i2c_addr, reg, 1, &buf, 1); return buf; }
void i2c_reg_write(uchar i2c_addr, uchar reg, uchar val) { i2c_write(i2c_addr, reg, 1, &val, 1); }
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cpu/mpc8xx, however, adds i2c_init() calls:
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uchar i2c_reg_read(uchar i2c_addr, uchar reg) { uchar buf;
i2c_init(CFG_I2C_SPEED, CFG_I2C_SLAVE); i2c_read(i2c_addr, reg, 1, &buf, 1); return (buf); }
void i2c_reg_write(uchar i2c_addr, uchar reg, uchar val) { i2c_init(CFG_I2C_SPEED, CFG_I2C_SLAVE); i2c_write(i2c_addr, reg, 1, &val, 1); }
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Can somebody lend historical perspective as to why these i2c_init() calls are needed?
thanks, Ben