hybridgroup.gobot/drivers/i2c/mcp23017_driver.go

436 lines
14 KiB
Go

package i2c
import (
"fmt"
"log"
"strings"
"gobot.io/x/gobot/v2"
)
// default address for device when a2/a1/a0 pins are all tied to ground
// please consider special handling for MCP23S17
const mcp23017DefaultAddress = 0x20
const mcp23017Debug = false // toggle debugging information
// port contains all the registers for the device.
type port struct {
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
}
// A bank is made up of PortA and PortB pins.
// Port B pins are on the left side of the chip (starting with pin 1), while port A pins are on the right side.
type bank struct {
portA port
portB port
}
// 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
seqop uint8
disslw uint8
haen uint8
odr uint8
intpol uint8
}
type mcp23017Behavior struct {
forceRefresh bool
autoIODirOff bool
}
// MCP23017Driver contains the driver configuration parameters.
type MCP23017Driver struct {
*Driver
mcpConf mcp23017Config
mcpBehav mcp23017Behavior
gobot.Eventer
}
// NewMCP23017Driver creates a new Gobot Driver to the MCP23017 i2c port expander.
// Params:
//
// c Connector - the Adaptor to use with this Driver
//
// Optional params:
//
// i2c.WithBus(int): bus to use with this driver
// i2c.WithAddress(int): address to use with this driver
// i2c.WithMCP23017Bank(int): MCP23017 bank to use with this driver
// i2c.WithMCP23017Mirror(int): MCP23017 mirror to use with this driver
// i2c.WithMCP23017Seqop(int): MCP23017 seqop to use with this driver
// i2c.WithMCP23017Disslw(int): MCP23017 disslw to use with this driver
// i2c.WithMCP23017Haen(int): MCP23017 haen to use with this driver
// i2c.WithMCP23017Odr(int): MCP23017 odr to use with this driver
// i2c.WithMCP23017Intpol(int): MCP23017 intpol to use with this driver
func NewMCP23017Driver(c Connector, options ...func(Config)) *MCP23017Driver {
d := &MCP23017Driver{
Driver: NewDriver(c, "MCP23017", mcp23017DefaultAddress),
mcpConf: mcp23017Config{},
Eventer: gobot.NewEventer(),
}
d.afterStart = d.initialize
for _, option := range options {
option(d)
}
d.AddCommand("WriteGPIO", func(params map[string]interface{}) interface{} {
pin := params["pin"].(uint8)
port := params["port"].(string)
val := params["val"].(uint8)
err := d.WriteGPIO(pin, port, val)
return map[string]interface{}{"err": err}
})
d.AddCommand("ReadGPIO", func(params map[string]interface{}) interface{} {
pin := params["pin"].(uint8)
port := params["port"].(string)
val, err := d.ReadGPIO(pin, port)
return map[string]interface{}{"val": val, "err": err}
})
return d
}
// WithMCP23017Bank option sets the MCP23017Driver bank option
func WithMCP23017Bank(val uint8) func(Config) {
return func(c Config) {
d, ok := c.(*MCP23017Driver)
if ok {
d.mcpConf.bank = val
} else if mcp23017Debug {
log.Printf("trying to set bank for non-MCP23017Driver %v", c)
}
}
}
// WithMCP23017Mirror option sets the MCP23017Driver mirror option
func WithMCP23017Mirror(val uint8) func(Config) {
return func(c Config) {
d, ok := c.(*MCP23017Driver)
if ok {
d.mcpConf.mirror = val
} else if mcp23017Debug {
log.Printf("Trying to set mirror for non-MCP23017Driver %v", c)
}
}
}
// WithMCP23017Seqop option sets the MCP23017Driver seqop option
func WithMCP23017Seqop(val uint8) func(Config) {
return func(c Config) {
d, ok := c.(*MCP23017Driver)
if ok {
d.mcpConf.seqop = val
} else if mcp23017Debug {
log.Printf("Trying to set seqop for non-MCP23017Driver %v", c)
}
}
}
// WithMCP23017Disslw option sets the MCP23017Driver disslw option
func WithMCP23017Disslw(val uint8) func(Config) {
return func(c Config) {
d, ok := c.(*MCP23017Driver)
if ok {
d.mcpConf.disslw = val
} else if mcp23017Debug {
log.Printf("Trying to set disslw for non-MCP23017Driver %v", c)
}
}
}
// WithMCP23017Haen option sets the MCP23017Driver haen option
// This feature is only available for MCP23S17, because address pins are always enabled on the MCP23017.
func WithMCP23017Haen(val uint8) func(Config) {
return func(c Config) {
d, ok := c.(*MCP23017Driver)
if ok {
d.mcpConf.haen = val
} else if mcp23017Debug {
log.Printf("Trying to set haen for non-MCP23017Driver %v", c)
}
}
}
// WithMCP23017Odr option sets the MCP23017Driver odr option
func WithMCP23017Odr(val uint8) func(Config) {
return func(c Config) {
d, ok := c.(*MCP23017Driver)
if ok {
d.mcpConf.odr = val
} else if mcp23017Debug {
log.Printf("Trying to set odr for non-MCP23017Driver %v", c)
}
}
}
// WithMCP23017Intpol option sets the MCP23017Driver intpol option
func WithMCP23017Intpol(val uint8) func(Config) {
return func(c Config) {
d, ok := c.(*MCP23017Driver)
if ok {
d.mcpConf.intpol = val
} else if mcp23017Debug {
log.Printf("Trying to set intpol for non-MCP23017Driver %v", c)
}
}
}
// WithMCP23017ForceRefresh option modifies the MCP23017Driver forceRefresh option
// Setting to true (1) will force refresh operation to register, although there is no change.
// Normally this is not needed, so default is off (0).
// When there is something flaky, there is a small chance to stabilize by setting this flag to true.
// However, setting this flag to true slows down each IO operation up to 100%.
func WithMCP23017ForceRefresh(val uint8) func(Config) {
return func(c Config) {
d, ok := c.(*MCP23017Driver)
if ok {
d.mcpBehav.forceRefresh = val > 0
} else if mcp23017Debug {
log.Printf("Trying to set forceRefresh for non-MCP23017Driver %v", c)
}
}
}
// WithMCP23017AutoIODirOff option modifies the MCP23017Driver autoIODirOff option
// Set IO direction at each read or write operation ensures the correct direction, which is the default setting.
// Most hardware is configured statically, so this can avoided by setting the direction using SetPinMode(),
// e.g. in the start up sequence. If this way is taken, the automatic set of direction at each call can
// be safely deactivated with this flag (set to true, 1).
// This will speedup each WriteGPIO by 50% and each ReadGPIO by 60%.
func WithMCP23017AutoIODirOff(val uint8) func(Config) {
return func(c Config) {
d, ok := c.(*MCP23017Driver)
if ok {
d.mcpBehav.autoIODirOff = val > 0
} else if mcp23017Debug {
log.Printf("Trying to set autoIODirOff for non-MCP23017Driver %v", c)
}
}
}
// SetPinMode set pin mode of a given pin immediately, based on the value:
// val = 0 output
// val = 1 input
func (m *MCP23017Driver) SetPinMode(pin uint8, portStr string, val uint8) (err error) {
m.mutex.Lock()
defer m.mutex.Unlock()
selectedPort := m.getPort(portStr)
// Set IODIR register bit for given pin to an output/input.
if err = m.write(selectedPort.IODIR, pin, bitState(val)); err != nil {
return
}
return
}
// SetPullUp sets the pull up state of a given pin immediately, based on the value:
// val = 1 pull up enabled.
// val = 0 pull up disabled.
func (m *MCP23017Driver) SetPullUp(pin uint8, portStr string, val uint8) error {
m.mutex.Lock()
defer m.mutex.Unlock()
selectedPort := m.getPort(portStr)
return m.write(selectedPort.GPPU, pin, bitState(val))
}
// SetGPIOPolarity will change a given pin's polarity immediately, 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, portStr string, val uint8) (err error) {
m.mutex.Lock()
defer m.mutex.Unlock()
selectedPort := m.getPort(portStr)
return m.write(selectedPort.IPOL, pin, bitState(val))
}
// WriteGPIO writes a value to a gpio pin (0-7) and a port (A or B).
func (m *MCP23017Driver) WriteGPIO(pin uint8, portStr string, val uint8) (err error) {
m.mutex.Lock()
defer m.mutex.Unlock()
selectedPort := m.getPort(portStr)
if !m.mcpBehav.autoIODirOff {
// Set IODIR register bit for given pin to an output by clearing bit.
// can't call SetPinMode() because mutex will cause deadlock
if err = m.write(selectedPort.IODIR, pin, clear); err != nil {
return err
}
}
// write value to OLAT register bit
err = m.write(selectedPort.OLAT, pin, bitState(val))
if err != nil {
return err
}
return nil
}
// ReadGPIO reads a value from a given gpio pin (0-7) and a port (A or B).
func (m *MCP23017Driver) ReadGPIO(pin uint8, portStr string) (val uint8, err error) {
m.mutex.Lock()
defer m.mutex.Unlock()
selectedPort := m.getPort(portStr)
if !m.mcpBehav.autoIODirOff {
// Set IODIR register bit for given pin to an input by set bit.
// can't call SetPinMode() because mutex will cause deadlock
if err = m.write(selectedPort.IODIR, pin, set); err != nil {
return 0, err
}
}
val, err = m.read(selectedPort.GPIO)
if err != nil {
return val, err
}
val = 1 << pin & val
if val > 1 {
val = 1
}
return val, nil
}
func (m *MCP23017Driver) initialize() (err error) {
// Set IOCON register with MCP23017 configuration.
ioconReg := m.getPort("A").IOCON // IOCON address is the same for Port A or B.
ioconVal := m.mcpConf.getUint8Value()
if _, err := m.connection.Write([]uint8{ioconReg, ioconVal}); err != nil {
return err
}
return
}
// write gets the value of the passed in register, and then sets the bit specified
// by the pin to the given state.
func (m *MCP23017Driver) write(reg uint8, pin uint8, state bitState) (err error) {
valOrg, err := m.read(reg)
if err != nil {
return fmt.Errorf("MCP write-read: %v", err)
}
var val uint8
if state == clear {
val = clearBit(valOrg, pin)
} else {
val = setBit(valOrg, pin)
}
if val != valOrg || m.mcpBehav.forceRefresh {
if mcp23017Debug {
log.Printf("write done: MCP forceRefresh: %t, address: 0x%X, register: 0x%X, name: %s, value: 0x%X\n",
m.mcpBehav.forceRefresh, m.GetAddressOrDefault(mcp23017DefaultAddress), reg, m.getRegName(reg), val)
}
if err = m.connection.WriteByteData(reg, val); err != nil {
return fmt.Errorf("MCP write-WriteByteData(reg=%d,val=%d): %v", reg, val, err)
}
} else {
if mcp23017Debug {
log.Printf("write skipped: MCP forceRefresh: %t, address: 0x%X, register: 0x%X, name: %s, value: 0x%X\n",
m.mcpBehav.forceRefresh, m.GetAddressOrDefault(mcp23017DefaultAddress), reg, m.getRegName(reg), val)
}
}
return nil
}
// read get the data from a given register
// it is mainly a wrapper to create additional debug messages, when activated
func (m *MCP23017Driver) read(reg uint8) (val uint8, err error) {
val, err = m.connection.ReadByteData(reg)
if err != nil {
return val, fmt.Errorf("MCP write-ReadByteData(reg=%d): %v", reg, err)
}
if mcp23017Debug {
log.Printf("reading done: MCP autoIODirOff: %t, address: 0x%X, register:0x%X, name: %s, value: 0x%X\n",
m.mcpBehav.autoIODirOff, m.GetAddressOrDefault(mcp23017DefaultAddress), reg, m.getRegName(reg), val)
}
return val, nil
}
// getPort return the port (A or B) given a string and the bank.
// Port A is the default if an incorrect or no port is specified.
func (m *MCP23017Driver) getPort(portStr string) (selectedPort port) {
portStr = strings.ToUpper(portStr)
switch {
case portStr == "A":
return mcp23017GetBank(m.mcpConf.bank).portA
case portStr == "B":
return mcp23017GetBank(m.mcpConf.bank).portB
default:
return mcp23017GetBank(m.mcpConf.bank).portA
}
}
// 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
}
// getRegName returns the name of the given register related to the configured bank
// and can be used to write nice debug messages
func (m *MCP23017Driver) getRegName(reg uint8) string {
b := mcp23017GetBank(m.mcpConf.bank)
portStr := "A"
regStr := "unknown"
for i := 1; i <= 2; i++ {
if regStr == "unknown" {
p := b.portA
if i == 2 {
p = b.portB
portStr = "B"
}
switch reg {
case p.IODIR:
regStr = "IODIR"
case p.IPOL:
regStr = "IPOL"
case p.GPINTEN:
regStr = "GPINTEN"
case p.DEFVAL:
regStr = "DEFVAL"
case p.INTCON:
regStr = "INTCON"
case p.IOCON:
regStr = "IOCON"
case p.GPPU:
regStr = "GPPU"
case p.INTF:
regStr = "INTF"
case p.INTCAP:
regStr = "INTCAP"
case p.GPIO:
regStr = "GPIO"
case p.OLAT:
regStr = "OLAT"
}
}
}
return fmt.Sprintf("%s_%s", regStr, portStr)
}
// mcp23017GetBank returns a bank's PortA and PortB registers given a bank number (0/1).
func mcp23017GetBank(bnk uint8) bank {
if bnk == 0 {
return bank{portA: port{0x00, 0x02, 0x04, 0x06, 0x08, 0x0A, 0x0C, 0x0E, 0x10, 0x12, 0x14}, portB: port{0x01, 0x03, 0x05, 0x07, 0x09, 0x0B, 0x0D, 0x0F, 0x11, 0x13, 0x15}}
}
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}}
}