machine/k210: implement i2c.SetBaudRate()

Signed-off-by: deadprogram <[email protected]>

src/machine/machine_k210.go

@@ -566,16 +566,7 @@ func (i2c *I2C) Configure(config I2CConfig) error {
 		config.SCL.SetFPIOAFunction(FUNC_I2C2_SCLK)
 	}
 
-	div := CPUFrequency() / config.Frequency / 16
-
-	// Disable controller before setting the prescale register.
-	i2c.Bus.ENABLE.Set(0)
-
-	i2c.Bus.CON.Set(0x63)
-
-	// Set prescaler registers.
-	i2c.Bus.SS_SCL_HCNT.Set(uint32(div))
-	i2c.Bus.SS_SCL_LCNT.Set(uint32(div))
+	i2c.SetBaudRate(config.Frequency)
 
 	i2c.Bus.INTR_MASK.Set(0)
 	i2c.Bus.DMA_CR.Set(0x03)
@@ -587,7 +578,17 @@ func (i2c *I2C) Configure(config I2CConfig) error {
 
 // SetBaudRate sets the communication speed for I2C.
 func (i2c *I2C) SetBaudRate(br uint32) error {
-	// TODO: implement
+	div := CPUFrequency() / br / 16
+
+	// Disable controller before setting the prescale register.
+	i2c.Bus.ENABLE.Set(0)
+
+	i2c.Bus.CON.Set(0x63)
+
+	// Set prescaler registers.
+	i2c.Bus.SS_SCL_HCNT.Set(uint32(div))
+	i2c.Bus.SS_SCL_LCNT.Set(uint32(div))
+
 	return nil
 }