Implement PWM interface for SAMD21 (#157)

* machine/atsamd21: implement PWM interface for all pins that support it
* machine/atsamd21: correct PWM channel mapping for pin PA18
* machine/atsamd21: move clock init into InitPWM() to hopefully save power
Этот коммит содержится в:
Ron Evans 2019-01-28 13:48:52 +01:00 коммит произвёл GitHub
родитель 7461c298dd
коммит 19b4476cbb
Не найден ключ, соответствующий данной подписи
Идентификатор ключа GPG: 4AEE18F83AFDEB23
2 изменённых файлов: 428 добавлений и 220 удалений

Просмотреть файл

@ -4,20 +4,20 @@ package machine
// GPIO Pins // GPIO Pins
const ( const (
D0 = 11 // UART0 RX: SERCOM0/PAD[3] D0 = 11 // UART0 RX
D1 = 10 // UART0 TX: SERCOM0/PAD[2] D1 = 10 // UART0 TX
D2 = 14 D2 = 14
D3 = 9 D3 = 9 // PWM available
D4 = 8 D4 = 8 // PWM available
D5 = 15 D5 = 15 // PWM available
D6 = 20 D6 = 20 // PWM available
D7 = 21 D7 = 21
D8 = 6 D8 = 6 // PWM available
D9 = 7 D9 = 7 // PWM available
D10 = 18 // UART1 TX(1): SERCOM1/PAD[2] can be used for UART1 TX D10 = 18 // can be used for PWM or UART1 RX
D11 = 16 // UART1 TX(2): SERCOM1/PAD[0] can be used for UART1 TX D11 = 16 // can be used for PWM or UART1 TX
D12 = 19 D12 = 19 // PWM available
D13 = 17 D13 = 17 // PWM available
) )
const ( const (
@ -32,6 +32,6 @@ const (
// I2C pins // I2C pins
const ( const (
SDA_PIN = 22 // // SDA: SERCOM3/PAD[0] SDA_PIN = 22 // SDA: SERCOM3/PAD[0]
SCL_PIN = 23 // // SCL: SERCOM3/PAD[1] SCL_PIN = 23 // SCL: SERCOM3/PAD[1]
) )

Просмотреть файл

@ -77,224 +77,22 @@ func (p GPIO) Set(high bool) {
// getPMux returns the value for the correct PMUX register for this pin. // getPMux returns the value for the correct PMUX register for this pin.
func (p GPIO) getPMux() sam.RegValue8 { func (p GPIO) getPMux() sam.RegValue8 {
pin := p.Pin >> 1 return getPMux(p.Pin)
switch pin {
case 0:
return sam.PORT.PMUX0_0
case 1:
return sam.PORT.PMUX0_1
case 2:
return sam.PORT.PMUX0_2
case 3:
return sam.PORT.PMUX0_3
case 4:
return sam.PORT.PMUX0_4
case 5:
return sam.PORT.PMUX0_5
case 6:
return sam.PORT.PMUX0_6
case 7:
return sam.PORT.PMUX0_7
case 8:
return sam.PORT.PMUX0_8
case 9:
return sam.PORT.PMUX0_9
case 10:
return sam.PORT.PMUX0_10
case 11:
return sam.PORT.PMUX0_11
case 12:
return sam.PORT.PMUX0_12
case 13:
return sam.PORT.PMUX0_13
case 14:
return sam.PORT.PMUX0_14
case 15:
return sam.PORT.PMUX0_15
default:
return 0
}
} }
// setPMux sets the value for the correct PMUX register for this pin. // setPMux sets the value for the correct PMUX register for this pin.
func (p GPIO) setPMux(val sam.RegValue8) { func (p GPIO) setPMux(val sam.RegValue8) {
pin := p.Pin >> 1 setPMux(p.Pin, val)
switch pin {
case 0:
sam.PORT.PMUX0_0 = val
case 1:
sam.PORT.PMUX0_1 = val
case 2:
sam.PORT.PMUX0_2 = val
case 3:
sam.PORT.PMUX0_3 = val
case 4:
sam.PORT.PMUX0_4 = val
case 5:
sam.PORT.PMUX0_5 = val
case 6:
sam.PORT.PMUX0_6 = val
case 7:
sam.PORT.PMUX0_7 = val
case 8:
sam.PORT.PMUX0_8 = val
case 9:
sam.PORT.PMUX0_9 = val
case 10:
sam.PORT.PMUX0_10 = val
case 11:
sam.PORT.PMUX0_11 = val
case 12:
sam.PORT.PMUX0_12 = val
case 13:
sam.PORT.PMUX0_13 = val
case 14:
sam.PORT.PMUX0_14 = val
case 15:
sam.PORT.PMUX0_15 = val
}
} }
// getPinCfg returns the value for the correct PINCFG register for this pin. // getPinCfg returns the value for the correct PINCFG register for this pin.
func (p GPIO) getPinCfg() sam.RegValue8 { func (p GPIO) getPinCfg() sam.RegValue8 {
switch p.Pin { return getPinCfg(p.Pin)
case 0:
return sam.PORT.PINCFG0_0
case 1:
return sam.PORT.PINCFG0_1
case 2:
return sam.PORT.PINCFG0_2
case 3:
return sam.PORT.PINCFG0_3
case 4:
return sam.PORT.PINCFG0_4
case 5:
return sam.PORT.PINCFG0_5
case 6:
return sam.PORT.PINCFG0_6
case 7:
return sam.PORT.PINCFG0_7
case 8:
return sam.PORT.PINCFG0_8
case 9:
return sam.PORT.PINCFG0_9
case 10:
return sam.PORT.PINCFG0_10
case 11:
return sam.PORT.PINCFG0_11
case 12:
return sam.PORT.PINCFG0_12
case 13:
return sam.PORT.PINCFG0_13
case 14:
return sam.PORT.PINCFG0_14
case 15:
return sam.PORT.PINCFG0_15
case 16:
return sam.PORT.PINCFG0_16
case 17:
return sam.PORT.PINCFG0_17
case 18:
return sam.PORT.PINCFG0_18
case 19:
return sam.PORT.PINCFG0_19
case 20:
return sam.PORT.PINCFG0_20
case 21:
return sam.PORT.PINCFG0_21
case 22:
return sam.PORT.PINCFG0_22
case 23:
return sam.PORT.PINCFG0_23
case 24:
return sam.PORT.PINCFG0_24
case 25:
return sam.PORT.PINCFG0_25
case 26:
return sam.PORT.PINCFG0_26
case 27:
return sam.PORT.PINCFG0_27
case 28:
return sam.PORT.PINCFG0_28
case 29:
return sam.PORT.PINCFG0_29
case 30:
return sam.PORT.PINCFG0_30
case 31:
return sam.PORT.PINCFG0_31
default:
return 0
}
} }
// setPinCfg sets the value for the correct PINCFG register for this pin. // setPinCfg sets the value for the correct PINCFG register for this pin.
func (p GPIO) setPinCfg(val sam.RegValue8) { func (p GPIO) setPinCfg(val sam.RegValue8) {
switch p.Pin { setPinCfg(p.Pin, val)
case 0:
sam.PORT.PINCFG0_0 = val
case 1:
sam.PORT.PINCFG0_1 = val
case 2:
sam.PORT.PINCFG0_2 = val
case 3:
sam.PORT.PINCFG0_3 = val
case 4:
sam.PORT.PINCFG0_4 = val
case 5:
sam.PORT.PINCFG0_5 = val
case 6:
sam.PORT.PINCFG0_6 = val
case 7:
sam.PORT.PINCFG0_7 = val
case 8:
sam.PORT.PINCFG0_8 = val
case 9:
sam.PORT.PINCFG0_9 = val
case 10:
sam.PORT.PINCFG0_10 = val
case 11:
sam.PORT.PINCFG0_11 = val
case 12:
sam.PORT.PINCFG0_12 = val
case 13:
sam.PORT.PINCFG0_13 = val
case 14:
sam.PORT.PINCFG0_14 = val
case 15:
sam.PORT.PINCFG0_15 = val
case 16:
sam.PORT.PINCFG0_16 = val
case 17:
sam.PORT.PINCFG0_17 = val
case 18:
sam.PORT.PINCFG0_18 = val
case 19:
sam.PORT.PINCFG0_19 = val
case 20:
sam.PORT.PINCFG0_20 = val
case 21:
sam.PORT.PINCFG0_21 = val
case 22:
sam.PORT.PINCFG0_22 = val
case 23:
sam.PORT.PINCFG0_23 = val
case 24:
sam.PORT.PINCFG0_24 = val
case 25:
sam.PORT.PINCFG0_25 = val
case 26:
sam.PORT.PINCFG0_26 = val
case 27:
sam.PORT.PINCFG0_27 = val
case 28:
sam.PORT.PINCFG0_28 = val
case 29:
sam.PORT.PINCFG0_29 = val
case 30:
sam.PORT.PINCFG0_30 = val
case 31:
sam.PORT.PINCFG0_31 = val
}
} }
// UART on the SAMD21. // UART on the SAMD21.
@ -698,3 +496,413 @@ func (i2c I2C) readByte() byte {
} }
return byte(i2c.Bus.DATA) return byte(i2c.Bus.DATA)
} }
// PWM
const period = 0xFFFF
// InitPWM initializes the PWM interface.
func InitPWM() {
// turn on timer clocks used for PWM
sam.PM.APBCMASK |= sam.PM_APBCMASK_TCC0_ | sam.PM_APBCMASK_TCC1_ | sam.PM_APBCMASK_TCC2_
// Use GCLK0 for TCC0/TCC1
sam.GCLK.CLKCTRL = sam.RegValue16((sam.GCLK_CLKCTRL_ID_TCC0_TCC1 << sam.GCLK_CLKCTRL_ID_Pos) |
(sam.GCLK_CLKCTRL_GEN_GCLK0 << sam.GCLK_CLKCTRL_GEN_Pos) |
sam.GCLK_CLKCTRL_CLKEN)
for (sam.GCLK.STATUS & sam.GCLK_STATUS_SYNCBUSY) > 0 {
}
// Use GCLK0 for TCC2/TC3
sam.GCLK.CLKCTRL = sam.RegValue16((sam.GCLK_CLKCTRL_ID_TCC2_TC3 << sam.GCLK_CLKCTRL_ID_Pos) |
(sam.GCLK_CLKCTRL_GEN_GCLK0 << sam.GCLK_CLKCTRL_GEN_Pos) |
sam.GCLK_CLKCTRL_CLKEN)
for (sam.GCLK.STATUS & sam.GCLK_STATUS_SYNCBUSY) > 0 {
}
}
// Configure configures a PWM pin for output.
func (pwm PWM) Configure() {
// figure out which TCCX timer for this pin
timer := pwm.getTimer()
// disable timer
timer.CTRLA &^= sam.TCC_CTRLA_ENABLE
// Wait for synchronization
for (timer.SYNCBUSY & sam.TCC_SYNCBUSY_ENABLE) > 0 {
}
// Use "Normal PWM" (single-slope PWM)
timer.WAVE |= sam.TCC_WAVE_WAVEGEN_NPWM
// Wait for synchronization
for (timer.SYNCBUSY & sam.TCC_SYNCBUSY_WAVE) > 0 {
}
// Set the period (the number to count to (TOP) before resetting timer)
//TCC0->PER.reg = period;
timer.PER = period
// Wait for synchronization
for (timer.SYNCBUSY & sam.TCC_SYNCBUSY_PER) > 0 {
}
// Set pin as output
sam.PORT.DIRSET0 = (1 << pwm.Pin)
// Set pin to low
sam.PORT.OUTCLR0 = (1 << pwm.Pin)
// Enable the port multiplexer for pin
pwm.setPinCfg(sam.PORT_PINCFG0_PMUXEN)
// Connect TCCX timer to pin.
// we normally use the F channel aka ALT
pwmConfig := GPIO_PWM_ALT
// in the case of PA6 or PA7 we have to use E channel
if pwm.Pin == 6 || pwm.Pin == 7 {
pwmConfig = GPIO_PWM
}
if pwm.Pin&1 > 0 {
// odd pin, so save the even pins
val := pwm.getPMux() & sam.PORT_PMUX0_PMUXE_Msk
pwm.setPMux(val | sam.RegValue8(pwmConfig<<sam.PORT_PMUX0_PMUXO_Pos))
} else {
// even pin, so save the odd pins
val := pwm.getPMux() & sam.PORT_PMUX0_PMUXO_Msk
pwm.setPMux(val | sam.RegValue8(pwmConfig<<sam.PORT_PMUX0_PMUXE_Pos))
}
}
// Set turns on the duty cycle for a PWM pin using the provided value.
func (pwm PWM) Set(value uint16) {
// figure out which TCCX timer for this pin
timer := pwm.getTimer()
// disable output
timer.CTRLA &^= sam.TCC_CTRLA_ENABLE
// Wait for synchronization
for (timer.SYNCBUSY & sam.TCC_SYNCBUSY_ENABLE) > 0 {
}
// Set PWM signal to output duty cycle
pwm.setChannel(sam.RegValue(value))
// Wait for synchronization on all channels
for (timer.SYNCBUSY & (sam.TCC_SYNCBUSY_CC0 |
sam.TCC_SYNCBUSY_CC1 |
sam.TCC_SYNCBUSY_CC2 |
sam.TCC_SYNCBUSY_CC3)) > 0 {
}
// enable
timer.CTRLA |= sam.TCC_CTRLA_ENABLE
// Wait for synchronization
for (timer.SYNCBUSY & sam.TCC_SYNCBUSY_ENABLE) > 0 {
}
}
// getPMux returns the value for the correct PMUX register for this pin.
func (pwm PWM) getPMux() sam.RegValue8 {
return getPMux(pwm.Pin)
}
// setPMux sets the value for the correct PMUX register for this pin.
func (pwm PWM) setPMux(val sam.RegValue8) {
setPMux(pwm.Pin, val)
}
// getPinCfg returns the value for the correct PINCFG register for this pin.
func (pwm PWM) getPinCfg() sam.RegValue8 {
return getPinCfg(pwm.Pin)
}
// setPinCfg sets the value for the correct PINCFG register for this pin.
func (pwm PWM) setPinCfg(val sam.RegValue8) {
setPinCfg(pwm.Pin, val)
}
// getPMux returns the value for the correct PMUX register for this pin.
func getPMux(p uint8) sam.RegValue8 {
pin := p >> 1
switch pin {
case 0:
return sam.PORT.PMUX0_0
case 1:
return sam.PORT.PMUX0_1
case 2:
return sam.PORT.PMUX0_2
case 3:
return sam.PORT.PMUX0_3
case 4:
return sam.PORT.PMUX0_4
case 5:
return sam.PORT.PMUX0_5
case 6:
return sam.PORT.PMUX0_6
case 7:
return sam.PORT.PMUX0_7
case 8:
return sam.PORT.PMUX0_8
case 9:
return sam.PORT.PMUX0_9
case 10:
return sam.PORT.PMUX0_10
case 11:
return sam.PORT.PMUX0_11
case 12:
return sam.PORT.PMUX0_12
case 13:
return sam.PORT.PMUX0_13
case 14:
return sam.PORT.PMUX0_14
case 15:
return sam.PORT.PMUX0_15
default:
return 0
}
}
// setPMux sets the value for the correct PMUX register for this pin.
func setPMux(p uint8, val sam.RegValue8) {
pin := p >> 1
switch pin {
case 0:
sam.PORT.PMUX0_0 = val
case 1:
sam.PORT.PMUX0_1 = val
case 2:
sam.PORT.PMUX0_2 = val
case 3:
sam.PORT.PMUX0_3 = val
case 4:
sam.PORT.PMUX0_4 = val
case 5:
sam.PORT.PMUX0_5 = val
case 6:
sam.PORT.PMUX0_6 = val
case 7:
sam.PORT.PMUX0_7 = val
case 8:
sam.PORT.PMUX0_8 = val
case 9:
sam.PORT.PMUX0_9 = val
case 10:
sam.PORT.PMUX0_10 = val
case 11:
sam.PORT.PMUX0_11 = val
case 12:
sam.PORT.PMUX0_12 = val
case 13:
sam.PORT.PMUX0_13 = val
case 14:
sam.PORT.PMUX0_14 = val
case 15:
sam.PORT.PMUX0_15 = val
}
}
// getPinCfg returns the value for the correct PINCFG register for this pin.
func getPinCfg(p uint8) sam.RegValue8 {
switch p {
case 0:
return sam.PORT.PINCFG0_0
case 1:
return sam.PORT.PINCFG0_1
case 2:
return sam.PORT.PINCFG0_2
case 3:
return sam.PORT.PINCFG0_3
case 4:
return sam.PORT.PINCFG0_4
case 5:
return sam.PORT.PINCFG0_5
case 6:
return sam.PORT.PINCFG0_6
case 7:
return sam.PORT.PINCFG0_7
case 8:
return sam.PORT.PINCFG0_8
case 9:
return sam.PORT.PINCFG0_9
case 10:
return sam.PORT.PINCFG0_10
case 11:
return sam.PORT.PINCFG0_11
case 12:
return sam.PORT.PINCFG0_12
case 13:
return sam.PORT.PINCFG0_13
case 14:
return sam.PORT.PINCFG0_14
case 15:
return sam.PORT.PINCFG0_15
case 16:
return sam.PORT.PINCFG0_16
case 17:
return sam.PORT.PINCFG0_17
case 18:
return sam.PORT.PINCFG0_18
case 19:
return sam.PORT.PINCFG0_19
case 20:
return sam.PORT.PINCFG0_20
case 21:
return sam.PORT.PINCFG0_21
case 22:
return sam.PORT.PINCFG0_22
case 23:
return sam.PORT.PINCFG0_23
case 24:
return sam.PORT.PINCFG0_24
case 25:
return sam.PORT.PINCFG0_25
case 26:
return sam.PORT.PINCFG0_26
case 27:
return sam.PORT.PINCFG0_27
case 28:
return sam.PORT.PINCFG0_28
case 29:
return sam.PORT.PINCFG0_29
case 30:
return sam.PORT.PINCFG0_30
case 31:
return sam.PORT.PINCFG0_31
default:
return 0
}
}
// setPinCfg sets the value for the correct PINCFG register for this pin.
func setPinCfg(p uint8, val sam.RegValue8) {
switch p {
case 0:
sam.PORT.PINCFG0_0 = val
case 1:
sam.PORT.PINCFG0_1 = val
case 2:
sam.PORT.PINCFG0_2 = val
case 3:
sam.PORT.PINCFG0_3 = val
case 4:
sam.PORT.PINCFG0_4 = val
case 5:
sam.PORT.PINCFG0_5 = val
case 6:
sam.PORT.PINCFG0_6 = val
case 7:
sam.PORT.PINCFG0_7 = val
case 8:
sam.PORT.PINCFG0_8 = val
case 9:
sam.PORT.PINCFG0_9 = val
case 10:
sam.PORT.PINCFG0_10 = val
case 11:
sam.PORT.PINCFG0_11 = val
case 12:
sam.PORT.PINCFG0_12 = val
case 13:
sam.PORT.PINCFG0_13 = val
case 14:
sam.PORT.PINCFG0_14 = val
case 15:
sam.PORT.PINCFG0_15 = val
case 16:
sam.PORT.PINCFG0_16 = val
case 17:
sam.PORT.PINCFG0_17 = val
case 18:
sam.PORT.PINCFG0_18 = val
case 19:
sam.PORT.PINCFG0_19 = val
case 20:
sam.PORT.PINCFG0_20 = val
case 21:
sam.PORT.PINCFG0_21 = val
case 22:
sam.PORT.PINCFG0_22 = val
case 23:
sam.PORT.PINCFG0_23 = val
case 24:
sam.PORT.PINCFG0_24 = val
case 25:
sam.PORT.PINCFG0_25 = val
case 26:
sam.PORT.PINCFG0_26 = val
case 27:
sam.PORT.PINCFG0_27 = val
case 28:
sam.PORT.PINCFG0_28 = val
case 29:
sam.PORT.PINCFG0_29 = val
case 30:
sam.PORT.PINCFG0_30 = val
case 31:
sam.PORT.PINCFG0_31 = val
}
}
// getTimer returns the timer to be used for PWM on this pin
func (pwm PWM) getTimer() *sam.TCC_Type {
switch pwm.Pin {
case 6:
return sam.TCC1
case 7:
return sam.TCC1
case 8:
return sam.TCC1
case 9:
return sam.TCC1
case 14:
return sam.TCC0
case 15:
return sam.TCC0
case 16:
return sam.TCC0
case 17:
return sam.TCC0
case 18:
return sam.TCC0
case 19:
return sam.TCC0
case 20:
return sam.TCC0
case 21:
return sam.TCC0
default:
return nil // not supported on this pin
}
}
// setChannel sets the value for the correct channel for PWM on this pin
func (pwm PWM) setChannel(val sam.RegValue) {
switch pwm.Pin {
case 6:
pwm.getTimer().CC0 = val
case 7:
pwm.getTimer().CC1 = val
case 8:
pwm.getTimer().CC0 = val
case 9:
pwm.getTimer().CC1 = val
case 14:
pwm.getTimer().CC0 = val
case 15:
pwm.getTimer().CC1 = val
case 16:
pwm.getTimer().CC2 = val
case 17:
pwm.getTimer().CC3 = val
case 18:
pwm.getTimer().CC2 = val
case 19:
pwm.getTimer().CC3 = val
case 20:
pwm.getTimer().CC2 = val
case 21:
pwm.getTimer().CC3 = val
default:
return // not supported on this pin
}
}