machine/stm32: add i2c Frequency and SetBaudRate() function for boards that were missing implementation

Signed-off-by: deadprogram <ron@hybridgroup.com>

src/machine/machine_stm32_i2c_revb.go

@@ -45,11 +45,21 @@ type I2C struct {
 
 // I2CConfig is used to store config info for I2C.
 type I2CConfig struct {
-	SCL Pin
+	Frequency uint32
-	SDA Pin
+	SCL       Pin
+	SDA       Pin
 }
 
 func (i2c *I2C) Configure(config I2CConfig) error {
+	// Frequency range
+	switch config.Frequency {
+	case 0:
+		config.Frequency = 100 * KHz
+	case 10 * KHz, 100 * KHz, 400 * KHz, 500 * KHz:
+	default:
+		return errI2CNotImplemented
+	}
+
 	// disable I2C interface before any configuration changes
 	i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_PE)
 
@@ -63,8 +73,7 @@ func (i2c *I2C) Configure(config I2CConfig) error {
 	}
 	i2c.configurePins(config)
 
-	// Frequency range
+	i2c.Bus.TIMINGR.Set(i2c.getFreqRange(config.Frequency))
-	i2c.Bus.TIMINGR.Set(i2c.getFreqRange())
 
 	// Disable Own Address1 before set the Own Address1 configuration
 	i2c.Bus.OAR1.ClearBits(stm32.I2C_OAR1_OA1EN)
@@ -86,8 +95,21 @@ func (i2c *I2C) Configure(config I2CConfig) error {
 
 // SetBaudRate sets the communication speed for I2C.
 func (i2c *I2C) SetBaudRate(br uint32) error {
-	// TODO: implement
+	switch br {
-	return errI2CNotImplemented
+	case 10 * KHz, 100 * KHz, 400 * KHz, 500 * KHz:
+	default:
+		return errI2CNotImplemented
+	}
+
+	// disable I2C interface before any configuration changes
+	i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_PE)
+
+	i2c.Bus.TIMINGR.Set(i2c.getFreqRange(br))
+
+	// Disable Generalcall and NoStretch, Enable peripheral
+	i2c.Bus.CR1.Set(stm32.I2C_CR1_PE)
+
+	return nil
 }
 
 func (i2c *I2C) Tx(addr uint16, w, r []byte) error {

src/machine/machine_stm32f7x2.go

@@ -51,9 +51,20 @@ func (uart *UART) setRegisters() {
 //---------- I2C related code
 
 // Gets the value for TIMINGR register
-func (i2c *I2C) getFreqRange() uint32 {
+func (i2c *I2C) getFreqRange(br uint32) uint32 {
 	// This is a 'magic' value calculated by STM32CubeMX
 	// for 27MHz PCLK1 (216MHz CPU Freq / 8).
 	// TODO: Do calculations based on PCLK1
-	return 0x00606A9B
+	switch br {
+	case 10 * KHz:
+		return 0x5010C0FF
+	case 100 * KHz:
+		return 0x00606A9B
+	case 400 * KHz:
+		return 0x00201625
+	case 500 * KHz:
+		return 0x00100429
+	default:
+		return 0
+	}
 }

src/machine/machine_stm32l0.go

@@ -298,9 +298,20 @@ func (spi SPI) configurePins(config SPIConfig) {
 //---------- I2C related types and code
 
 // Gets the value for TIMINGR register
-func (i2c I2C) getFreqRange() uint32 {
+func (i2c I2C) getFreqRange(br uint32) uint32 {
 	// This is a 'magic' value calculated by STM32CubeMX
-	// for 80MHz PCLK1.
+	// for 16MHz PCLK1.
 	// TODO: Do calculations based on PCLK1
-	return 0x00303D5B
+	switch br {
+	case 10 * KHz:
+		return 0x40003EFF
+	case 100 * KHz:
+		return 0x00303D5B
+	case 400 * KHz:
+		return 0x0010061A
+	case 500 * KHz:
+		return 0x00000117
+	default:
+		return 0
+	}
 }

src/machine/machine_stm32l4x2.go

@@ -17,9 +17,20 @@ const APB2_TIM_FREQ = 80e6 // 80MHz
 //---------- I2C related code
 
 // Gets the value for TIMINGR register
-func (i2c *I2C) getFreqRange() uint32 {
+func (i2c *I2C) getFreqRange(br uint32) uint32 {
-	// This is a 'magic' value calculated by STM32CubeMX
+	// These are 'magic' values calculated by STM32CubeMX
 	// for 80MHz PCLK1.
 	// TODO: Do calculations based on PCLK1
-	return 0x10909CEC
+	switch br {
+	case 10 * KHz:
+		return 0xF010F3FE
+	case 100 * KHz:
+		return 0x10909CEC
+	case 400 * KHz:
+		return 0x00702991
+	case 500 * KHz:
+		return 0x00300E84
+	default:
+		return 0
+	}
 }

src/machine/machine_stm32l4x5.go

@@ -17,9 +17,20 @@ const APB2_TIM_FREQ = 120e6 // 120MHz
 //---------- I2C related code
 
 // Gets the value for TIMINGR register
-func (i2c *I2C) getFreqRange() uint32 {
+func (i2c *I2C) getFreqRange(br uint32) uint32 {
 	// This is a 'magic' value calculated by STM32CubeMX
 	// for 120MHz PCLK1.
 	// TODO: Do calculations based on PCLK1
-	return 0x307075B1
+	switch br {
+	case 10 * KHz:
+		return 0x0 // does this even work? zero is weird here.
+	case 100 * KHz:
+		return 0x307075B1
+	case 400 * KHz:
+		return 0x00B03FDB
+	case 500 * KHz:
+		return 0x005017C7
+	default:
+		return 0
+	}
 }

src/machine/machine_stm32l4x6.go

@@ -17,9 +17,20 @@ const APB2_TIM_FREQ = 80e6 // 80MHz
 //---------- I2C related code
 
 // Gets the value for TIMINGR register
-func (i2c *I2C) getFreqRange() uint32 {
+func (i2c *I2C) getFreqRange(br uint32) uint32 {
 	// This is a 'magic' value calculated by STM32CubeMX
 	// for 80MHz PCLK1.
 	// TODO: Do calculations based on PCLK1
-	return 0x10909CEC
+	switch br {
+	case 10 * KHz:
+		return 0xF010F3FE
+	case 100 * KHz:
+		return 0x10909CEC
+	case 400 * KHz:
+		return 0x00702991
+	case 500 * KHz:
+		return 0x00300E84
+	default:
+		return 0
+	}
 }

src/machine/machine_stm32l5x2.go

@@ -49,9 +49,20 @@ func (uart *UART) setRegisters() {
 //---------- I2C related code
 
 // Gets the value for TIMINGR register
-func (i2c *I2C) getFreqRange() uint32 {
+func (i2c *I2C) getFreqRange(br uint32) uint32 {
 	// This is a 'magic' value calculated by STM32CubeMX
 	// for 110MHz PCLK1.
 	// TODO: Do calculations based on PCLK1
-	return 0x40505681
+	switch br {
+	case 10 * KHz:
+		return 0x0 // does this even work? zero is weird here.
+	case 100 * KHz:
+		return 0x40505681
+	case 400 * KHz:
+		return 0x00A03AC8
+	case 500 * KHz:
+		return 0x005015B6
+	default:
+		return 0
+	}
 }

src/machine/machine_stm32wlx.go

@@ -289,11 +289,22 @@ func (spi SPI) getBaudRate(config SPIConfig) uint32 {
 //---------- I2C related code
 
 // Gets the value for TIMINGR register
-func (i2c *I2C) getFreqRange() uint32 {
+func (i2c *I2C) getFreqRange(br uint32) uint32 {
 	// This is a 'magic' value calculated by STM32CubeMX
 	// for 48Mhz PCLK1.
 	// TODO: Do calculations based on PCLK1
-	return 0x20303E5D
+	switch br {
+	case 10 * KHz:
+		return 0x9010DEFF
+	case 100 * KHz:
+		return 0x20303E5D
+	case 400 * KHz:
+		return 0x2010091A
+	case 500 * KHz:
+		return 0x00201441
+	default:
+		return 0
+	}
 }
 
 //---------- UART related code