mirror of
https://github.com/stianeikeland/go-rpio.git
synced 2025-01-23 02:31:05 +01:00
add support for PWM balanced mode
This commit is contained in:
youngkin
parent
2ab4c0432c
commit
02c0360e26
64
rpio.go
64
rpio.go
|
|
@ -100,10 +100,10 @@ const (
|
|||
|
||||
// BCM 2711 has a different mechanism for pull-up/pull-down/enable
|
||||
const (
|
||||
GPPUPPDN0 = 57 // Pin pull-up/down for pins 15:0
|
||||
GPPUPPDN1 = 58 // Pin pull-up/down for pins 31:16
|
||||
GPPUPPDN2 = 59 // Pin pull-up/down for pins 47:32
|
||||
GPPUPPDN3 = 60 // Pin pull-up/down for pins 57:48
|
||||
GPPUPPDN0 = 57 // Pin pull-up/down for pins 15:0
|
||||
GPPUPPDN1 = 58 // Pin pull-up/down for pins 31:16
|
||||
GPPUPPDN2 = 59 // Pin pull-up/down for pins 47:32
|
||||
GPPUPPDN3 = 60 // Pin pull-up/down for pins 57:48
|
||||
)
|
||||
|
||||
var (
|
||||
|
|
@ -146,6 +146,12 @@ const (
|
|||
High
|
||||
)
|
||||
|
||||
// Which PWM algorithm to use, Balanced or Mark/Space
|
||||
const (
|
||||
Balanced = iota
|
||||
MarkSpace
|
||||
)
|
||||
|
||||
// Pull Up / Down / Off
|
||||
const (
|
||||
PullOff Pull = iota
|
||||
|
|
@ -222,6 +228,11 @@ func (pin Pin) DutyCycle(dutyLen, cycleLen uint32) {
|
|||
SetDutyCycle(pin, dutyLen, cycleLen)
|
||||
}
|
||||
|
||||
// DutyCycleMsen: Set duty cycle for Pwm pin (see doc of SetDutyCycle)
|
||||
func (pin Pin) DutyCycleMsen(dutyLen, cycleLen, msen uint32) {
|
||||
SetDutyCycleMsen(pin, dutyLen, cycleLen, msen)
|
||||
}
|
||||
|
||||
// Mode: Set pin Mode
|
||||
func (pin Pin) Mode(mode Mode) {
|
||||
PinMode(pin, mode)
|
||||
|
|
@ -259,7 +270,7 @@ func (pin Pin) PullOff() {
|
|||
|
||||
func (pin Pin) ReadPull() Pull {
|
||||
if !isBCM2711() {
|
||||
return PullNone // Can't read pull-up/pull-down state on other Pi boards
|
||||
return PullNone // Can't read pull-up/pull-down state on other Pi boards
|
||||
}
|
||||
|
||||
reg := GPPUPPDN0 + (uint8(pin) >> 4)
|
||||
|
|
@ -272,7 +283,7 @@ func (pin Pin) ReadPull() Pull {
|
|||
case 2:
|
||||
return PullDown
|
||||
default:
|
||||
return PullNone // Invalid
|
||||
return PullNone // Invalid
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -481,51 +492,51 @@ func EdgeDetected(pin Pin) bool {
|
|||
}
|
||||
|
||||
func PullMode(pin Pin, pull Pull) {
|
||||
|
||||
|
||||
memlock.Lock()
|
||||
defer memlock.Unlock()
|
||||
|
||||
if isBCM2711() {
|
||||
pullreg := GPPUPPDN0 + (pin >> 4)
|
||||
pullshift := (pin & 0xf) << 1
|
||||
|
||||
var p uint32
|
||||
|
||||
|
||||
var p uint32
|
||||
|
||||
switch pull {
|
||||
case PullOff:
|
||||
p = 0
|
||||
case PullUp:
|
||||
p = 1
|
||||
case PullDown:
|
||||
p = 2;
|
||||
p = 2
|
||||
}
|
||||
|
||||
|
||||
// This is verbatim C code from raspi-gpio.c
|
||||
pullbits := gpioMem[pullreg]
|
||||
pullbits &= ^(3 << pullshift)
|
||||
pullbits |= (p << pullshift)
|
||||
gpioMem[pullreg]= pullbits
|
||||
gpioMem[pullreg] = pullbits
|
||||
} else {
|
||||
// Pull up/down/off register has offset 38 / 39, pull is 37
|
||||
pullClkReg := pin/32 + 38
|
||||
pullReg := 37
|
||||
shift := pin % 32
|
||||
|
||||
|
||||
switch pull {
|
||||
case PullDown, PullUp:
|
||||
gpioMem[pullReg] |= uint32(pull)
|
||||
case PullOff:
|
||||
gpioMem[pullReg] &^= 3
|
||||
}
|
||||
|
||||
|
||||
// Wait for value to clock in, this is ugly, sorry :(
|
||||
time.Sleep(time.Microsecond)
|
||||
|
||||
|
||||
gpioMem[pullClkReg] = 1 << shift
|
||||
|
||||
|
||||
// Wait for value to clock in
|
||||
time.Sleep(time.Microsecond)
|
||||
|
||||
|
||||
gpioMem[pullReg] &^= 3
|
||||
gpioMem[pullClkReg] = 0
|
||||
}
|
||||
|
|
@ -550,7 +561,7 @@ func SetFreq(pin Pin, freq int) {
|
|||
if isBCM2711() {
|
||||
sourceFreq = 52000000
|
||||
}
|
||||
const divMask = 4095 // divi and divf have 12 bits each
|
||||
const divMask = 4095 // divi and divf have 12 bits each
|
||||
|
||||
divi := uint32(sourceFreq / freq)
|
||||
divf := uint32(((sourceFreq % freq) << 12) / freq)
|
||||
|
|
@ -628,11 +639,22 @@ func SetFreq(pin Pin, freq int) {
|
|||
// channel 1 (pwm0) for pins 12, 18, 40
|
||||
// channel 2 (pwm1) for pins 13, 19, 41, 45.
|
||||
func SetDutyCycle(pin Pin, dutyLen, cycleLen uint32) {
|
||||
SetDutyCycleMsen(pin, dutyLen, cycleLen, 1) // Default PWM algorithm is Mark/Space, msen = 1
|
||||
|
||||
}
|
||||
|
||||
// SetDutyCycleMsen extends SetDutyCycle to allow for the specification of the PWM
|
||||
// algorithm to be used, Balanced or Mark/Space. 'msen' is used to indicate which
|
||||
// PWM algorithm to use. The constants Balanced or Markspace should be used as the
|
||||
// value. See 'SetDutyCycle(pin, dutyLen, cycleLen)' above for more information
|
||||
// regarding how to use 'SetDutyCycleMsen()'
|
||||
func SetDutyCycleMsen(pin Pin, dutyLen, cycleLen, msen uint32) {
|
||||
const pwmCtlReg = 0
|
||||
var (
|
||||
pwmDatReg uint
|
||||
pwmRngReg uint
|
||||
shift uint // offset inside ctlReg
|
||||
|
||||
)
|
||||
|
||||
switch pin {
|
||||
|
|
@ -646,11 +668,12 @@ func SetDutyCycle(pin Pin, dutyLen, cycleLen uint32) {
|
|||
shift = 8
|
||||
default:
|
||||
return
|
||||
|
||||
}
|
||||
|
||||
const ctlMask = 255 // ctl setting has 8 bits for each channel
|
||||
const pwen = 1 << 0 // enable pwm
|
||||
const msen = 1 << 7 // use M/S transition instead of pwm algorithm
|
||||
msen = msen << 7
|
||||
|
||||
// reset settings
|
||||
pwmMem[pwmCtlReg] = pwmMem[pwmCtlReg]&^(ctlMask<<shift) | msen<<shift | pwen<<shift
|
||||
|
|
@ -660,6 +683,7 @@ func SetDutyCycle(pin Pin, dutyLen, cycleLen uint32) {
|
|||
time.Sleep(time.Microsecond * 10)
|
||||
|
||||
// NOTE without root permission this changes will simply do nothing successfully
|
||||
|
||||
}
|
||||
|
||||
// StopPwm: Stop pwm for both channels
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user