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Code cleanup, improve go report card
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@ulisesflynn
ulisesflynn committed Mar 8, 2016
1 parent 88fd93f commit 30a8aa2
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Showing 2 changed files with 230 additions and 111 deletions.
110 changes: 59 additions & 51 deletions platforms/i2c/mcp23017_driver.go
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Original file line number Diff line number Diff line change
Expand Up @@ -17,8 +17,7 @@ limitations under the License.
package i2c

import (
"bytes"
"encoding/binary"
"fmt"
"log"
"strings"
"time"
Expand All @@ -27,24 +26,24 @@ import (
)

var (
Debug = true // Set this to true to see debugging information
debug = false // Set this to true to see debugging information
// Register this Driver
_ gobot.Driver = (*MCP23017Driver)(nil)
)

// Port contains all the registers for the device.
type port struct {
IODIR byte // I/O direction register: 0=output / 1=input
IPOL byte // Input polarity register: 0=normal polarity / 1=inversed
GPINTEN byte // Interrupt on change control register: 0=disabled / 1=enabled
DEFVAL byte // Default compare register for interrupt on change
INTCON byte // Interrupt control register: bit set to 0= use defval bit value to compare pin value/ bit set to 1= pin value compared to previous pin value
IOCON byte // Configuration register
GPPU byte // Pull-up resistor configuration register: 0=enabled / 1=disabled
INTF byte // Interrupt flag register: 0=no interrupt / 1=pin caused interrupt
INTCAP byte // Interrupt capture register, captures pin values during interrupt: 0=logic low / 1=logic high
GPIO byte // Port register, reading from this register reads the port
OLAT byte // Output latch register, write modifies the pins: 0=logic low / 1=logic high
IODIR uint8 // I/O direction register: 0=output / 1=input
IPOL uint8 // Input polarity register: 0=normal polarity / 1=inversed
GPINTEN uint8 // Interrupt on change control register: 0=disabled / 1=enabled
DEFVAL uint8 // Default compare register for interrupt on change
INTCON uint8 // Interrupt control register: bit set to 0= use defval bit value to compare pin value/ bit set to 1= pin value compared to previous pin value
IOCON uint8 // Configuration register
GPPU uint8 // Pull-up resistor configuration register: 0=enabled / 1=disabled
INTF uint8 // Interrupt flag register: 0=no interrupt / 1=pin caused interrupt
INTCAP uint8 // Interrupt capture register, captures pin values during interrupt: 0=logic low / 1=logic high
GPIO uint8 // Port register, reading from this register reads the port
OLAT uint8 // Output latch register, write modifies the pins: 0=logic low / 1=logic high
}

// Registers in the MCP23017 have different address based on which bank is used.
Expand All @@ -62,7 +61,8 @@ func getBank(bnk uint8) bank {
return bank{PortA: port{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A}, PortB: port{0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A}}
}

// MCP23017Config contains the device configuration settings to be loaded at startup.
// MCP23017Config contains the device configuration for the IOCON register.
// These fields should only be set with values 0 or 1.
type MCP23017Config struct {
Bank uint8
Mirror uint8
Expand All @@ -73,12 +73,12 @@ type MCP23017Config struct {
Intpol uint8
}

// getBytes returns the mcp23017 configuration as a slice of bytes.
func (conf *MCP23017Config) getBytes() []byte {
return []byte{conf.Bank, conf.Mirror, conf.Seqop, conf.Disslw, conf.Haen, conf.Odr, conf.Intpol}
// GetUint8Value returns the configuration data as a packed value.
func (mc *MCP23017Config) GetUint8Value() uint8 {
return mc.Bank<<7 | mc.Mirror<<6 | mc.Seqop<<5 | mc.Disslw<<4 | mc.Haen<<3 | mc.Odr<<2 | mc.Intpol<<1
}

// MCP23107Driver contains the driver configuration parameters.
// MCP23017Driver contains the driver configuration parameters.
type MCP23017Driver struct {
name string
connection I2c
Expand All @@ -101,14 +101,15 @@ func NewMCP23017Driver(a I2c, name string, conf MCP23017Config, deviceAddress in
}

m.AddCommand("WriteGPIO", func(params map[string]interface{}) interface{} {
pin := params["pin"].(float64)
val := params["val"].(float64)
pin := params["pin"].(uint8)
val := params["val"].(uint8)
port := params["port"].(string)
return m.WriteGPIO(pin, val, port)
err := m.WriteGPIO(pin, val, port)
return map[string]interface{}{"err": err}
})

m.AddCommand("ReadGPIO", func(params map[string]interface{}) interface{} {
pin := params["pin"].(float64)
pin := params["pin"].(uint8)
port := params["port"].(string)
val, err := m.ReadGPIO(pin, port)
return map[string]interface{}{"val": val, "err": err}
Expand All @@ -117,34 +118,31 @@ func NewMCP23017Driver(a I2c, name string, conf MCP23017Config, deviceAddress in
return m
}

// Name return the driver name.
func (m *MCP23017Driver) Name() string { return m.name }

// Connection returns the I2c connection.
func (m *MCP23017Driver) Connection() gobot.Connection { return m.connection.(gobot.Connection) }

// Halt stops the driver.
func (m *MCP23017Driver) Halt() (err []error) { return }

// Start writes initialization bytes and reads.
// Start writes the device configuration.
func (m *MCP23017Driver) Start() (errs []error) {
if err := m.connection.I2cStart(m.mcp23017Address); err != nil {
return []error{err}
}
// Set IOCON register with the given configuration.
selectedPort := m.getPort("A") // IOCON address is the same for Port A or B.
var ioval uint8
buf := bytes.NewReader(m.conf.getBytes())
err := binary.Read(buf, binary.LittleEndian, &ioval)
if err != nil {
return []error{err}
}
if err := m.connection.I2cWrite(m.mcp23017Address, []byte{selectedPort.IOCON, ioval}); err != nil {
// Set IOCON register with MCP23017 configuration.
ioconReg := m.getPort("A").IOCON // IOCON address is the same for Port A or B.
ioconVal := m.conf.GetUint8Value()
if err := m.connection.I2cWrite(m.mcp23017Address, []uint8{ioconReg, ioconVal}); err != nil {
return []error{err}
}
return
}

// WriteGPIO writes a value to a gpio pin (0-7) and a
// port (A or B).
func (m *MCP23017Driver) WriteGPIO(pin float64, val float64, portStr string) (err error) {
// WriteGPIO writes a value to a gpio pin (0-7) and a port (A or B).
func (m *MCP23017Driver) WriteGPIO(pin uint8, val uint8, portStr string) (err error) {
selectedPort := m.getPort(portStr)
// Set IODIR register bit for given pin to an output.
if err := m.write(selectedPort.IODIR, uint8(pin), 0); err != nil {
Expand All @@ -159,19 +157,19 @@ func (m *MCP23017Driver) WriteGPIO(pin float64, val float64, portStr string) (er

// ReadGPIO reads a value from a given gpio pin (0-7) and a
// port (A or B).
func (m *MCP23017Driver) ReadGPIO(pin float64, portStr string) (val bool, err error) {
func (m *MCP23017Driver) ReadGPIO(pin uint8, portStr string) (val uint8, err error) {
selectedPort := m.getPort(portStr)
gpio, err := m.read(selectedPort.GPIO)
val, err = m.read(selectedPort.GPIO)
if err != nil {
return false, err
return val, err
}
return ((1 << uint8(pin) & gpio) != 0), nil
return (1 << uint8(pin) & val), nil
}

// SetPullUp sets the pull up state of a given pin based on the value:
// val = 1 pull up enabled.
// val = 0 pull up disabled.
func (m *MCP23017Driver) SetPullUp(pin uint8, val byte, portStr string) error {
func (m *MCP23017Driver) SetPullUp(pin uint8, val uint8, portStr string) error {
selectedPort := m.getPort(portStr)
if err := m.write(selectedPort.GPPU, pin, val); err != nil {
return err
Expand All @@ -182,7 +180,7 @@ func (m *MCP23017Driver) SetPullUp(pin uint8, val byte, portStr string) error {
// SetGPIOPolarity will change a given pin's polarity based on the value:
// val = 1 opposite logic state of the input pin.
// val = 0 same logic state of the input pin.
func (m *MCP23017Driver) SetGPIOPolarity(pin uint8, val byte, portStr string) (err error) {
func (m *MCP23017Driver) SetGPIOPolarity(pin uint8, val uint8, portStr string) (err error) {
selectedPort := m.getPort(portStr)
if err := m.write(selectedPort.IPOL, pin, val); err != nil {
return err
Expand All @@ -192,7 +190,7 @@ func (m *MCP23017Driver) SetGPIOPolarity(pin uint8, val byte, portStr string) (e

// write gets the value of the passed in register, and then overwrites
// the bit specified by the pin, with the given value.
func (m *MCP23017Driver) write(reg byte, pin uint8, val byte) (err error) {
func (m *MCP23017Driver) write(reg uint8, pin uint8, val uint8) (err error) {
var ioval uint8
iodir, err := m.read(reg)
if err != nil {
Expand All @@ -203,23 +201,33 @@ func (m *MCP23017Driver) write(reg byte, pin uint8, val byte) (err error) {
} else if val == 1 {
ioval = setBit(iodir, uint8(pin))
}
if err = m.connection.I2cWrite(m.mcp23017Address, []byte{reg, ioval}); err != nil {
if debug {
log.Printf("Writing: MCP address: 0x%X, register: 0x%X\t, value: 0x%X\n", m.mcp23017Address, reg, ioval)
}
if err = m.connection.I2cWrite(m.mcp23017Address, []uint8{reg, ioval}); err != nil {
return err
}
return nil
}

// Read returns the values in the given register.
func (m *MCP23017Driver) read(reg byte) (val uint8, err error) {
bytesToRead := int(reg)
v, err := m.connection.I2cRead(m.mcp23017Address, bytesToRead+1)
// read get the data from a given register. The I2cRead does not read a specific
// register from the device, rather it will read n bytes starting at the base
// device address. To read a specific register, read register + 1 bytes, and then index
// the result with the given register to get the value.
func (m *MCP23017Driver) read(reg uint8) (val uint8, err error) {
register := int(reg)
bytesToRead := register + 1
v, err := m.connection.I2cRead(m.mcp23017Address, bytesToRead)
if err != nil {
return val, err
}
if Debug {
log.Printf("Register addr:0x%X val: 0x%X\n", reg, v[bytesToRead])
if len(v) != bytesToRead {
return val, fmt.Errorf("Read was unable to get %d bytes for register: 0x%X\n", bytesToRead, reg)
}
if debug {
log.Printf("Reading: MCP address: 0x%X, register:0x%X\t,value: 0x%X\n", m.mcp23017Address, reg, v[register])
}
return v[bytesToRead], nil
return v[register], nil
}

// getPort return the port (A or B) given a string and the bank.
Expand Down
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