Files
tinygo/src/machine/machine_atsamd51.go
T
Ayke van Laethem 2f1f8fb075 machine: move PinMode to central location
It is always implemented exactly the same way (as an uint8) so there is
no reason to implement it in each target separately.

This also makes it easier to add some documentation to it.
2021-05-06 13:59:12 +02:00

2715 lines
80 KiB
Go

// +build sam,atsamd51 sam,atsame5x
// Peripheral abstraction layer for the atsamd51.
//
// Datasheet:
// http://ww1.microchip.com/downloads/en/DeviceDoc/60001507C.pdf
//
package machine
import (
"device/arm"
"device/sam"
"errors"
"runtime/interrupt"
"runtime/volatile"
"unsafe"
)
func CPUFrequency() uint32 {
return 120000000
}
const (
PinAnalog PinMode = 1
PinSERCOM PinMode = 2
PinSERCOMAlt PinMode = 3
PinTimer PinMode = 4
PinTimerAlt PinMode = 5
PinTCCPDEC PinMode = 6
PinCom PinMode = 7
PinSDHC PinMode = 8
PinI2S PinMode = 9
PinPCC PinMode = 10
PinGMAC PinMode = 11
PinACCLK PinMode = 12
PinCCL PinMode = 13
PinDigital PinMode = 14
PinInput PinMode = 15
PinInputPullup PinMode = 16
PinOutput PinMode = 17
PinTCCE PinMode = PinTimer
PinTCCF PinMode = PinTimerAlt
PinTCCG PinMode = PinTCCPDEC
PinInputPulldown PinMode = 18
PinCAN PinMode = 19
PinCAN0 PinMode = PinSDHC
PinCAN1 PinMode = PinCom
)
type PinChange uint8
// Pin change interrupt constants for SetInterrupt.
const (
PinRising PinChange = sam.EIC_CONFIG_SENSE0_RISE
PinFalling PinChange = sam.EIC_CONFIG_SENSE0_FALL
PinToggle PinChange = sam.EIC_CONFIG_SENSE0_BOTH
)
// Callbacks to be called for pins configured with SetInterrupt. Unfortunately,
// we also need to keep track of which interrupt channel is used by which pin,
// as the only alternative would be iterating through all pins.
//
// We're using the magic constant 16 here because the SAM D21 has 16 interrupt
// channels configurable for pins.
var (
interruptPins [16]Pin // warning: the value is invalid when pinCallbacks[i] is not set!
pinCallbacks [16]func(Pin)
)
// Hardware pins
const (
PA00 Pin = 0
PA01 Pin = 1
PA02 Pin = 2
PA03 Pin = 3
PA04 Pin = 4
PA05 Pin = 5
PA06 Pin = 6
PA07 Pin = 7
PA08 Pin = 8
PA09 Pin = 9
PA10 Pin = 10
PA11 Pin = 11
PA12 Pin = 12
PA13 Pin = 13
PA14 Pin = 14
PA15 Pin = 15
PA16 Pin = 16
PA17 Pin = 17
PA18 Pin = 18
PA19 Pin = 19
PA20 Pin = 20
PA21 Pin = 21
PA22 Pin = 22
PA23 Pin = 23
PA24 Pin = 24
PA25 Pin = 25
PA26 Pin = 26
PA27 Pin = 27
PA28 Pin = 28
PA29 Pin = 29
PA30 Pin = 30
PA31 Pin = 31
PB00 Pin = 32
PB01 Pin = 33
PB02 Pin = 34
PB03 Pin = 35
PB04 Pin = 36
PB05 Pin = 37
PB06 Pin = 38
PB07 Pin = 39
PB08 Pin = 40
PB09 Pin = 41
PB10 Pin = 42
PB11 Pin = 43
PB12 Pin = 44
PB13 Pin = 45
PB14 Pin = 46
PB15 Pin = 47
PB16 Pin = 48
PB17 Pin = 49
PB18 Pin = 50
PB19 Pin = 51
PB20 Pin = 52
PB21 Pin = 53
PB22 Pin = 54
PB23 Pin = 55
PB24 Pin = 56
PB25 Pin = 57
PB26 Pin = 58
PB27 Pin = 59
PB28 Pin = 60
PB29 Pin = 61
PB30 Pin = 62
PB31 Pin = 63
PC00 Pin = 64
PC01 Pin = 65
PC02 Pin = 66
PC03 Pin = 67
PC04 Pin = 68
PC05 Pin = 69
PC06 Pin = 70
PC07 Pin = 71
PC08 Pin = 72
PC09 Pin = 73
PC10 Pin = 74
PC11 Pin = 75
PC12 Pin = 76
PC13 Pin = 77
PC14 Pin = 78
PC15 Pin = 79
PC16 Pin = 80
PC17 Pin = 81
PC18 Pin = 82
PC19 Pin = 83
PC20 Pin = 84
PC21 Pin = 85
PC22 Pin = 86
PC23 Pin = 87
PC24 Pin = 88
PC25 Pin = 89
PC26 Pin = 90
PC27 Pin = 91
PC28 Pin = 92
PC29 Pin = 93
PC30 Pin = 94
PC31 Pin = 95
PD00 Pin = 96
PD01 Pin = 97
PD02 Pin = 98
PD03 Pin = 99
PD04 Pin = 100
PD05 Pin = 101
PD06 Pin = 102
PD07 Pin = 103
PD08 Pin = 104
PD09 Pin = 105
PD10 Pin = 106
PD11 Pin = 107
PD12 Pin = 108
PD13 Pin = 109
PD14 Pin = 110
PD15 Pin = 111
PD16 Pin = 112
PD17 Pin = 113
PD18 Pin = 114
PD19 Pin = 115
PD20 Pin = 116
PD21 Pin = 117
PD22 Pin = 118
PD23 Pin = 119
PD24 Pin = 120
PD25 Pin = 121
PD26 Pin = 122
PD27 Pin = 123
PD28 Pin = 124
PD29 Pin = 125
PD30 Pin = 126
PD31 Pin = 127
)
const (
pinPadMapSERCOM0Pad0 uint16 = 0x1000
pinPadMapSERCOM1Pad0 uint16 = 0x2000
pinPadMapSERCOM2Pad0 uint16 = 0x3000
pinPadMapSERCOM3Pad0 uint16 = 0x4000
pinPadMapSERCOM4Pad0 uint16 = 0x5000
pinPadMapSERCOM5Pad0 uint16 = 0x6000
pinPadMapSERCOM6Pad0 uint16 = 0x7000
pinPadMapSERCOM7Pad0 uint16 = 0x8000
pinPadMapSERCOM0Pad2 uint16 = 0x1200
pinPadMapSERCOM1Pad2 uint16 = 0x2200
pinPadMapSERCOM2Pad2 uint16 = 0x3200
pinPadMapSERCOM3Pad2 uint16 = 0x4200
pinPadMapSERCOM4Pad2 uint16 = 0x5200
pinPadMapSERCOM5Pad2 uint16 = 0x6200
pinPadMapSERCOM6Pad2 uint16 = 0x7200
pinPadMapSERCOM7Pad2 uint16 = 0x8200
pinPadMapSERCOM0AltPad0 uint16 = 0x0010
pinPadMapSERCOM1AltPad0 uint16 = 0x0020
pinPadMapSERCOM2AltPad0 uint16 = 0x0030
pinPadMapSERCOM3AltPad0 uint16 = 0x0040
pinPadMapSERCOM4AltPad0 uint16 = 0x0050
pinPadMapSERCOM5AltPad0 uint16 = 0x0060
pinPadMapSERCOM6AltPad0 uint16 = 0x0070
pinPadMapSERCOM7AltPad0 uint16 = 0x0080
pinPadMapSERCOM0AltPad1 uint16 = 0x0011
pinPadMapSERCOM1AltPad1 uint16 = 0x0021
pinPadMapSERCOM2AltPad1 uint16 = 0x0031
pinPadMapSERCOM3AltPad1 uint16 = 0x0041
pinPadMapSERCOM4AltPad1 uint16 = 0x0051
pinPadMapSERCOM5AltPad1 uint16 = 0x0061
pinPadMapSERCOM6AltPad1 uint16 = 0x0071
pinPadMapSERCOM7AltPad1 uint16 = 0x0081
pinPadMapSERCOM0AltPad2 uint16 = 0x0012
pinPadMapSERCOM1AltPad2 uint16 = 0x0022
pinPadMapSERCOM2AltPad2 uint16 = 0x0032
pinPadMapSERCOM3AltPad2 uint16 = 0x0042
pinPadMapSERCOM4AltPad2 uint16 = 0x0052
pinPadMapSERCOM5AltPad2 uint16 = 0x0062
pinPadMapSERCOM6AltPad2 uint16 = 0x0072
pinPadMapSERCOM7AltPad2 uint16 = 0x0082
)
// pinPadMapping lists which pins have which SERCOMs attached to them.
// The encoding is rather dense, with each uint16 encoding two pins and both
// SERCOM and SERCOM-ALT.
//
// Observations:
// * There are eight SERCOMs. Those SERCOM numbers can be encoded in 4 bits.
// * Even pad numbers are usually on even pins, and odd pad numbers are usually
// on odd pins. The exception is SERCOM-ALT, which sometimes swaps pad 0 and 1.
// With that, there is still an invariant that the pad number for an odd pin is
// the pad number for the corresponding even pin with the low bit toggled.
// * Pin pads come in pairs. If PA00 has pad 0, then PA01 has pad 1.
// With this information, we can encode SERCOM pin/pad numbers much more
// efficiently. Due to pads coming in pairs, we can ignore half the pins: the
// information for an odd pin can be calculated easily from the preceding even
// pin.
//
// Each word below is split in two bytes. The 8 high bytes are for SERCOM and
// the 8 low bits are for SERCOM-ALT. Of each byte, the 4 high bits encode the
// SERCOM + 1 while the two low bits encodes the pad number (the pad number for
// the odd pin can be trivially calculated by toggling the low bit of the pad
// number). It encodes SERCOM + 1 instead of just the SERCOM number, to make it
// easy to check whether a nibble is set at all.
//
// Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/60001507E.pdf
var pinPadMapping = [64]uint16{
// page 32
PA00 / 2: 0 | pinPadMapSERCOM1AltPad0,
// page 33
PB08 / 2: 0 | pinPadMapSERCOM4AltPad0,
PA04 / 2: 0 | pinPadMapSERCOM0AltPad0,
PA06 / 2: 0 | pinPadMapSERCOM0AltPad2,
PC04 / 2: pinPadMapSERCOM6Pad0 | 0,
PC06 / 2: pinPadMapSERCOM6Pad2 | 0,
PA08 / 2: pinPadMapSERCOM0Pad0 | pinPadMapSERCOM2AltPad1,
PA10 / 2: pinPadMapSERCOM0Pad2 | pinPadMapSERCOM2AltPad2,
PB10 / 2: 0 | pinPadMapSERCOM4AltPad2,
PB12 / 2: pinPadMapSERCOM4Pad0 | 0,
PB14 / 2: pinPadMapSERCOM4Pad2 | 0,
PD08 / 2: pinPadMapSERCOM7Pad0 | pinPadMapSERCOM6AltPad1,
PD10 / 2: pinPadMapSERCOM7Pad2 | pinPadMapSERCOM6AltPad2,
PC10 / 2: pinPadMapSERCOM6Pad2 | pinPadMapSERCOM7AltPad2,
// page 34
PC12 / 2: pinPadMapSERCOM7Pad0 | pinPadMapSERCOM6AltPad1,
PC14 / 2: pinPadMapSERCOM7Pad2 | pinPadMapSERCOM6AltPad2,
PA12 / 2: pinPadMapSERCOM2Pad0 | pinPadMapSERCOM4AltPad1,
PA14 / 2: pinPadMapSERCOM2Pad2 | pinPadMapSERCOM4AltPad2,
PA16 / 2: pinPadMapSERCOM1Pad0 | pinPadMapSERCOM3AltPad1,
PA18 / 2: pinPadMapSERCOM1Pad2 | pinPadMapSERCOM3AltPad2,
PC16 / 2: pinPadMapSERCOM6Pad0 | pinPadMapSERCOM0AltPad1,
PC18 / 2: pinPadMapSERCOM6Pad2 | pinPadMapSERCOM0AltPad2,
PC22 / 2: pinPadMapSERCOM1Pad0 | pinPadMapSERCOM3AltPad1,
PD20 / 2: pinPadMapSERCOM1Pad2 | pinPadMapSERCOM3AltPad2,
PB16 / 2: pinPadMapSERCOM5Pad0 | 0,
PB18 / 2: pinPadMapSERCOM5Pad2 | pinPadMapSERCOM7AltPad2,
// page 35
PB20 / 2: pinPadMapSERCOM3Pad0 | pinPadMapSERCOM7AltPad1,
PA20 / 2: pinPadMapSERCOM5Pad2 | pinPadMapSERCOM3AltPad2,
PA22 / 2: pinPadMapSERCOM3Pad0 | pinPadMapSERCOM5AltPad1,
PA24 / 2: pinPadMapSERCOM3Pad2 | pinPadMapSERCOM5AltPad2,
PB22 / 2: pinPadMapSERCOM1Pad2 | pinPadMapSERCOM5AltPad2,
PB24 / 2: pinPadMapSERCOM0Pad0 | pinPadMapSERCOM2AltPad1,
PB26 / 2: pinPadMapSERCOM2Pad0 | pinPadMapSERCOM4AltPad1,
PB28 / 2: pinPadMapSERCOM2Pad2 | pinPadMapSERCOM4AltPad2,
PC24 / 2: pinPadMapSERCOM0Pad2 | pinPadMapSERCOM2AltPad2,
//PC26 / 2: pinPadMapSERCOM1Pad1 | 0, // note: PC26 doesn't support SERCOM, but PC27 does
//PC28 / 2: pinPadMapSERCOM1Pad1 | 0, // note: PC29 doesn't exist in the datasheet?
PA30 / 2: 0 | pinPadMapSERCOM1AltPad2,
// page 36
PB30 / 2: 0 | pinPadMapSERCOM5AltPad1,
PB00 / 2: 0 | pinPadMapSERCOM5AltPad2,
PB02 / 2: 0 | pinPadMapSERCOM5AltPad0,
}
// findPinPadMapping looks up the pad number and the pinmode for a given pin and
// SERCOM number. The result can either be SERCOM, SERCOM-ALT, or "not found"
// (indicated by returning ok=false). The pad number is returned to calculate
// the DOPO/DIPO bitfields of the various serial peripherals.
func findPinPadMapping(sercom uint8, pin Pin) (pinMode PinMode, pad uint32, ok bool) {
if int(pin)/2 >= len(pinPadMapping) {
// This is probably NoPin, for which no mapping is available.
return
}
bytes := pinPadMapping[pin/2]
upper := byte(bytes >> 8)
lower := byte(bytes & 0xff)
if upper != 0 {
// SERCOM
if (upper>>4)-1 == sercom {
pinMode = PinSERCOM
pad |= uint32(upper % 4)
ok = true
}
}
if lower != 0 {
// SERCOM-ALT
if (lower>>4)-1 == sercom {
pinMode = PinSERCOMAlt
pad |= uint32(lower % 4)
ok = true
}
}
if ok {
// If the pin is uneven, toggle the lowest bit of the pad number.
if pin&1 != 0 {
pad ^= 1
}
}
return
}
// SetInterrupt sets an interrupt to be executed when a particular pin changes
// state. The pin should already be configured as an input, including a pull up
// or down if no external pull is provided.
//
// This call will replace a previously set callback on this pin. You can pass a
// nil func to unset the pin change interrupt. If you do so, the change
// parameter is ignored and can be set to any value (such as 0).
func (p Pin) SetInterrupt(change PinChange, callback func(Pin)) error {
// Most pins follow a common pattern where the EXTINT value is the pin
// number modulo 16. However, there are a few exceptions, as you can see
// below.
extint := uint8(0)
switch p {
case PA08:
// Connected to NMI. This is not currently supported.
return ErrInvalidInputPin
case PB26:
extint = 12
case PB27:
extint = 13
case PB28:
extint = 14
case PB29:
extint = 15
case PC07:
extint = 9
case PD08:
extint = 3
case PD09:
extint = 4
case PD10:
extint = 5
case PD11:
extint = 6
case PD12:
extint = 7
case PD20:
extint = 10
case PD21:
extint = 11
default:
// All other pins follow a normal pattern.
extint = uint8(p) % 16
}
if callback == nil {
// Disable this pin interrupt (if it was enabled).
sam.EIC.INTENCLR.Set(1 << extint)
if pinCallbacks[extint] != nil {
pinCallbacks[extint] = nil
}
return nil
}
if pinCallbacks[extint] != nil {
// The pin was already configured.
// To properly re-configure a pin, unset it first and set a new
// configuration.
return ErrNoPinChangeChannel
}
pinCallbacks[extint] = callback
interruptPins[extint] = p
if !sam.EIC.CTRLA.HasBits(sam.EIC_CTRLA_ENABLE) {
// EIC peripheral has not yet been initialized. Initialize it now.
// The EIC needs two clocks: CLK_EIC_APB and GCLK_EIC. CLK_EIC_APB is
// enabled by default, so doesn't have to be re-enabled. The other is
// required for detecting edges and must be enabled manually.
sam.GCLK.PCHCTRL[4].Set((sam.GCLK_PCHCTRL_GEN_GCLK0 << sam.GCLK_PCHCTRL_GEN_Pos) | sam.GCLK_PCHCTRL_CHEN)
// should not be necessary (CLKCTRL is not synchronized)
for sam.GCLK.SYNCBUSY.HasBits(sam.GCLK_SYNCBUSY_GENCTRL_GCLK0 << sam.GCLK_SYNCBUSY_GENCTRL_Pos) {
}
}
// CONFIG register is enable-protected, so disable EIC.
sam.EIC.CTRLA.ClearBits(sam.EIC_CTRLA_ENABLE)
// Configure this pin. Set the 4 bits of the EIC.CONFIGx register to the
// sense value (filter bit set to 0, sense bits set to the change value).
addr := &sam.EIC.CONFIG[0]
if extint >= 8 {
addr = &sam.EIC.CONFIG[1]
}
pos := (extint % 8) * 4 // bit position in register
addr.ReplaceBits(uint32(change), 0xf, pos)
// Enable external interrupt for this pin.
sam.EIC.INTENSET.Set(1 << extint)
sam.EIC.CTRLA.Set(sam.EIC_CTRLA_ENABLE)
for sam.EIC.SYNCBUSY.HasBits(sam.EIC_SYNCBUSY_ENABLE) {
}
// Set the PMUXEN flag, while keeping the INEN and PULLEN flags (if they
// were set before). This avoids clearing the pin pull mode while
// configuring the pin interrupt.
p.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN | (p.getPinCfg() & (sam.PORT_GROUP_PINCFG_INEN | sam.PORT_GROUP_PINCFG_PULLEN)))
if p&1 > 0 {
// odd pin, so save the even pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
p.setPMux(val | (0 << sam.PORT_GROUP_PMUX_PMUXO_Pos))
} else {
// even pin, so save the odd pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
p.setPMux(val | (0 << sam.PORT_GROUP_PMUX_PMUXE_Pos))
}
handleEICInterrupt := func(interrupt.Interrupt) {
flags := sam.EIC.INTFLAG.Get()
sam.EIC.INTFLAG.Set(flags) // clear interrupt
for i := uint(0); i < 16; i++ { // there are 16 channels
if flags&(1<<i) != 0 {
pinCallbacks[i](interruptPins[i])
}
}
}
switch extint {
case 0:
interrupt.New(sam.IRQ_EIC_EXTINT_0, handleEICInterrupt).Enable()
case 1:
interrupt.New(sam.IRQ_EIC_EXTINT_1, handleEICInterrupt).Enable()
case 2:
interrupt.New(sam.IRQ_EIC_EXTINT_2, handleEICInterrupt).Enable()
case 3:
interrupt.New(sam.IRQ_EIC_EXTINT_3, handleEICInterrupt).Enable()
case 4:
interrupt.New(sam.IRQ_EIC_EXTINT_4, handleEICInterrupt).Enable()
case 5:
interrupt.New(sam.IRQ_EIC_EXTINT_5, handleEICInterrupt).Enable()
case 6:
interrupt.New(sam.IRQ_EIC_EXTINT_6, handleEICInterrupt).Enable()
case 7:
interrupt.New(sam.IRQ_EIC_EXTINT_7, handleEICInterrupt).Enable()
case 8:
interrupt.New(sam.IRQ_EIC_EXTINT_8, handleEICInterrupt).Enable()
case 9:
interrupt.New(sam.IRQ_EIC_EXTINT_9, handleEICInterrupt).Enable()
case 10:
interrupt.New(sam.IRQ_EIC_EXTINT_10, handleEICInterrupt).Enable()
case 11:
interrupt.New(sam.IRQ_EIC_EXTINT_11, handleEICInterrupt).Enable()
case 12:
interrupt.New(sam.IRQ_EIC_EXTINT_12, handleEICInterrupt).Enable()
case 13:
interrupt.New(sam.IRQ_EIC_EXTINT_13, handleEICInterrupt).Enable()
case 14:
interrupt.New(sam.IRQ_EIC_EXTINT_14, handleEICInterrupt).Enable()
case 15:
interrupt.New(sam.IRQ_EIC_EXTINT_15, handleEICInterrupt).Enable()
}
return nil
}
// Return the register and mask to enable a given GPIO pin. This can be used to
// implement bit-banged drivers.
func (p Pin) PortMaskSet() (*uint32, uint32) {
group, pin_in_group := p.getPinGrouping()
return &sam.PORT.GROUP[group].OUTSET.Reg, 1 << pin_in_group
}
// Return the register and mask to disable a given port. This can be used to
// implement bit-banged drivers.
func (p Pin) PortMaskClear() (*uint32, uint32) {
group, pin_in_group := p.getPinGrouping()
return &sam.PORT.GROUP[group].OUTCLR.Reg, 1 << pin_in_group
}
// Set the pin to high or low.
// Warning: only use this on an output pin!
func (p Pin) Set(high bool) {
group, pin_in_group := p.getPinGrouping()
if high {
sam.PORT.GROUP[group].OUTSET.Set(1 << pin_in_group)
} else {
sam.PORT.GROUP[group].OUTCLR.Set(1 << pin_in_group)
}
}
// Get returns the current value of a GPIO pin.
func (p Pin) Get() bool {
group, pin_in_group := p.getPinGrouping()
return (sam.PORT.GROUP[group].IN.Get()>>pin_in_group)&1 > 0
}
// Toggle switches an output pin from low to high or from high to low.
// Warning: only use this on an output pin!
func (p Pin) Toggle() {
group, pin_in_group := p.getPinGrouping()
sam.PORT.GROUP[group].OUTTGL.Set(1 << pin_in_group)
}
// Configure this pin with the given configuration.
func (p Pin) Configure(config PinConfig) {
group, pin_in_group := p.getPinGrouping()
switch config.Mode {
case PinOutput:
sam.PORT.GROUP[group].DIRSET.Set(1 << pin_in_group)
// output is also set to input enable so pin can read back its own value
p.setPinCfg(sam.PORT_GROUP_PINCFG_INEN)
case PinInput:
sam.PORT.GROUP[group].DIRCLR.Set(1 << pin_in_group)
p.setPinCfg(sam.PORT_GROUP_PINCFG_INEN)
case PinInputPulldown:
sam.PORT.GROUP[group].DIRCLR.Set(1 << pin_in_group)
sam.PORT.GROUP[group].OUTCLR.Set(1 << pin_in_group)
p.setPinCfg(sam.PORT_GROUP_PINCFG_INEN | sam.PORT_GROUP_PINCFG_PULLEN)
case PinInputPullup:
sam.PORT.GROUP[group].DIRCLR.Set(1 << pin_in_group)
sam.PORT.GROUP[group].OUTSET.Set(1 << pin_in_group)
p.setPinCfg(sam.PORT_GROUP_PINCFG_INEN | sam.PORT_GROUP_PINCFG_PULLEN)
case PinSERCOM:
if p&1 > 0 {
// odd pin, so save the even pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
p.setPMux(val | (uint8(PinSERCOM) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
} else {
// even pin, so save the odd pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
p.setPMux(val | (uint8(PinSERCOM) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
}
// enable port config
p.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN | sam.PORT_GROUP_PINCFG_DRVSTR | sam.PORT_GROUP_PINCFG_INEN)
case PinSERCOMAlt:
if p&1 > 0 {
// odd pin, so save the even pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
p.setPMux(val | (uint8(PinSERCOMAlt) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
} else {
// even pin, so save the odd pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
p.setPMux(val | (uint8(PinSERCOMAlt) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
}
// enable port config
p.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN | sam.PORT_GROUP_PINCFG_DRVSTR)
case PinCom:
if p&1 > 0 {
// odd pin, so save the even pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
p.setPMux(val | (uint8(PinCom) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
} else {
// even pin, so save the odd pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
p.setPMux(val | (uint8(PinCom) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
}
// enable port config
p.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN)
case PinAnalog:
if p&1 > 0 {
// odd pin, so save the even pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
p.setPMux(val | (uint8(PinAnalog) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
} else {
// even pin, so save the odd pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
p.setPMux(val | (uint8(PinAnalog) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
}
// enable port config
p.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN | sam.PORT_GROUP_PINCFG_DRVSTR)
case PinSDHC:
if p&1 > 0 {
// odd pin, so save the even pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
p.setPMux(val | (uint8(PinSDHC) << sam.PORT_GROUP_PMUX_PMUXO_Pos))
} else {
// even pin, so save the odd pins
val := p.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
p.setPMux(val | (uint8(PinSDHC) << sam.PORT_GROUP_PMUX_PMUXE_Pos))
}
// enable port config
p.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN)
}
}
// getPMux returns the value for the correct PMUX register for this pin.
func (p Pin) getPMux() uint8 {
group, pin_in_group := p.getPinGrouping()
return sam.PORT.GROUP[group].PMUX[pin_in_group>>1].Get()
}
// setPMux sets the value for the correct PMUX register for this pin.
func (p Pin) setPMux(val uint8) {
group, pin_in_group := p.getPinGrouping()
sam.PORT.GROUP[group].PMUX[pin_in_group>>1].Set(val)
}
// getPinCfg returns the value for the correct PINCFG register for this pin.
func (p Pin) getPinCfg() uint8 {
group, pin_in_group := p.getPinGrouping()
return sam.PORT.GROUP[group].PINCFG[pin_in_group].Get()
}
// setPinCfg sets the value for the correct PINCFG register for this pin.
func (p Pin) setPinCfg(val uint8) {
group, pin_in_group := p.getPinGrouping()
sam.PORT.GROUP[group].PINCFG[pin_in_group].Set(val)
}
// getPinGrouping calculates the gpio group and pin id from the pin number.
// Pins are split into groups of 32, and each group has its own set of
// control registers.
func (p Pin) getPinGrouping() (uint8, uint8) {
group := uint8(p) >> 5
pin_in_group := uint8(p) & 0x1f
return group, pin_in_group
}
// InitADC initializes the ADC.
func InitADC() {
// ADC Bias Calibration
// NVMCTRL_SW0 0x00800080
// #define ADC0_FUSES_BIASCOMP_ADDR NVMCTRL_SW0
// #define ADC0_FUSES_BIASCOMP_Pos 2 /**< \brief (NVMCTRL_SW0) ADC Comparator Scaling */
// #define ADC0_FUSES_BIASCOMP_Msk (_Ul(0x7) << ADC0_FUSES_BIASCOMP_Pos)
// #define ADC0_FUSES_BIASCOMP(value) (ADC0_FUSES_BIASCOMP_Msk & ((value) << ADC0_FUSES_BIASCOMP_Pos))
// #define ADC0_FUSES_BIASR2R_ADDR NVMCTRL_SW0
// #define ADC0_FUSES_BIASR2R_Pos 8 /**< \brief (NVMCTRL_SW0) ADC Bias R2R ampli scaling */
// #define ADC0_FUSES_BIASR2R_Msk (_Ul(0x7) << ADC0_FUSES_BIASR2R_Pos)
// #define ADC0_FUSES_BIASR2R(value) (ADC0_FUSES_BIASR2R_Msk & ((value) << ADC0_FUSES_BIASR2R_Pos))
// #define ADC0_FUSES_BIASREFBUF_ADDR NVMCTRL_SW0
// #define ADC0_FUSES_BIASREFBUF_Pos 5 /**< \brief (NVMCTRL_SW0) ADC Bias Reference Buffer Scaling */
// #define ADC0_FUSES_BIASREFBUF_Msk (_Ul(0x7) << ADC0_FUSES_BIASREFBUF_Pos)
// #define ADC0_FUSES_BIASREFBUF(value) (ADC0_FUSES_BIASREFBUF_Msk & ((value) << ADC0_FUSES_BIASREFBUF_Pos))
// #define ADC1_FUSES_BIASCOMP_ADDR NVMCTRL_SW0
// #define ADC1_FUSES_BIASCOMP_Pos 16 /**< \brief (NVMCTRL_SW0) ADC Comparator Scaling */
// #define ADC1_FUSES_BIASCOMP_Msk (_Ul(0x7) << ADC1_FUSES_BIASCOMP_Pos)
// #define ADC1_FUSES_BIASCOMP(value) (ADC1_FUSES_BIASCOMP_Msk & ((value) << ADC1_FUSES_BIASCOMP_Pos))
// #define ADC1_FUSES_BIASR2R_ADDR NVMCTRL_SW0
// #define ADC1_FUSES_BIASR2R_Pos 22 /**< \brief (NVMCTRL_SW0) ADC Bias R2R ampli scaling */
// #define ADC1_FUSES_BIASR2R_Msk (_Ul(0x7) << ADC1_FUSES_BIASR2R_Pos)
// #define ADC1_FUSES_BIASR2R(value) (ADC1_FUSES_BIASR2R_Msk & ((value) << ADC1_FUSES_BIASR2R_Pos))
// #define ADC1_FUSES_BIASREFBUF_ADDR NVMCTRL_SW0
// #define ADC1_FUSES_BIASREFBUF_Pos 19 /**< \brief (NVMCTRL_SW0) ADC Bias Reference Buffer Scaling */
// #define ADC1_FUSES_BIASREFBUF_Msk (_Ul(0x7) << ADC1_FUSES_BIASREFBUF_Pos)
// #define ADC1_FUSES_BIASREFBUF(value) (ADC1_FUSES_BIASREFBUF_Msk & ((value) << ADC1_FUSES_BIASREFBUF_Pos))
adcFuse := *(*uint32)(unsafe.Pointer(uintptr(0x00800080)))
// uint32_t biascomp = (*((uint32_t *)ADC0_FUSES_BIASCOMP_ADDR) & ADC0_FUSES_BIASCOMP_Msk) >> ADC0_FUSES_BIASCOMP_Pos;
biascomp := (adcFuse & uint32(0x7<<2)) //>> 2
// uint32_t biasr2r = (*((uint32_t *)ADC0_FUSES_BIASR2R_ADDR) & ADC0_FUSES_BIASR2R_Msk) >> ADC0_FUSES_BIASR2R_Pos;
biasr2r := (adcFuse & uint32(0x7<<8)) //>> 8
// uint32_t biasref = (*((uint32_t *)ADC0_FUSES_BIASREFBUF_ADDR) & ADC0_FUSES_BIASREFBUF_Msk) >> ADC0_FUSES_BIASREFBUF_Pos;
biasref := (adcFuse & uint32(0x7<<5)) //>> 5
// calibrate ADC0
sam.ADC0.CALIB.Set(uint16(biascomp | biasr2r | biasref))
// biascomp = (*((uint32_t *)ADC1_FUSES_BIASCOMP_ADDR) & ADC1_FUSES_BIASCOMP_Msk) >> ADC1_FUSES_BIASCOMP_Pos;
biascomp = (adcFuse & uint32(0x7<<16)) //>> 16
// biasr2r = (*((uint32_t *)ADC1_FUSES_BIASR2R_ADDR) & ADC1_FUSES_BIASR2R_Msk) >> ADC1_FUSES_BIASR2R_Pos;
biasr2r = (adcFuse & uint32(0x7<<22)) //>> 22
// biasref = (*((uint32_t *)ADC1_FUSES_BIASREFBUF_ADDR) & ADC1_FUSES_BIASREFBUF_Msk) >> ADC1_FUSES_BIASREFBUF_Pos;
biasref = (adcFuse & uint32(0x7<<19)) //>> 19
// calibrate ADC1
sam.ADC1.CALIB.Set(uint16((biascomp | biasr2r | biasref) >> 16))
}
// Configure configures a ADCPin to be able to be used to read data.
func (a ADC) Configure(config ADCConfig) {
for _, adc := range []*sam.ADC_Type{sam.ADC0, sam.ADC1} {
for adc.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_CTRLB) {
} // wait for sync
adc.CTRLA.SetBits(sam.ADC_CTRLA_PRESCALER_DIV32 << sam.ADC_CTRLA_PRESCALER_Pos)
var resolution uint32
switch config.Resolution {
case 8:
resolution = sam.ADC_CTRLB_RESSEL_8BIT
case 10:
resolution = sam.ADC_CTRLB_RESSEL_10BIT
case 12:
resolution = sam.ADC_CTRLB_RESSEL_12BIT
case 16:
resolution = sam.ADC_CTRLB_RESSEL_16BIT
default:
resolution = sam.ADC_CTRLB_RESSEL_12BIT
}
adc.CTRLB.SetBits(uint16(resolution << sam.ADC_CTRLB_RESSEL_Pos))
adc.SAMPCTRL.Set(5) // sampling Time Length
for adc.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_SAMPCTRL) {
} // wait for sync
// No Negative input (Internal Ground)
adc.INPUTCTRL.Set(sam.ADC_INPUTCTRL_MUXNEG_GND << sam.ADC_INPUTCTRL_MUXNEG_Pos)
for adc.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_INPUTCTRL) {
} // wait for sync
// Averaging (see datasheet table in AVGCTRL register description)
var samples uint32
switch config.Samples {
case 1:
samples = sam.ADC_AVGCTRL_SAMPLENUM_1
case 2:
samples = sam.ADC_AVGCTRL_SAMPLENUM_2
case 4:
samples = sam.ADC_AVGCTRL_SAMPLENUM_4
case 8:
samples = sam.ADC_AVGCTRL_SAMPLENUM_8
case 16:
samples = sam.ADC_AVGCTRL_SAMPLENUM_16
case 32:
samples = sam.ADC_AVGCTRL_SAMPLENUM_32
case 64:
samples = sam.ADC_AVGCTRL_SAMPLENUM_64
case 128:
samples = sam.ADC_AVGCTRL_SAMPLENUM_128
case 256:
samples = sam.ADC_AVGCTRL_SAMPLENUM_256
case 512:
samples = sam.ADC_AVGCTRL_SAMPLENUM_512
case 1024:
samples = sam.ADC_AVGCTRL_SAMPLENUM_1024
default: // 1 sample only (no oversampling nor averaging), adjusting result by 0
samples = sam.ADC_AVGCTRL_SAMPLENUM_1
}
adc.AVGCTRL.Set(uint8(samples<<sam.ADC_AVGCTRL_SAMPLENUM_Pos) |
(0 << sam.ADC_AVGCTRL_ADJRES_Pos))
for adc.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_AVGCTRL) {
} // wait for sync
for adc.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_REFCTRL) {
} // wait for sync
// TODO: use config.Reference to set AREF level
// default is 3V3 reference voltage
adc.REFCTRL.SetBits(sam.ADC_REFCTRL_REFSEL_INTVCC1)
}
a.Pin.Configure(PinConfig{Mode: PinAnalog})
}
// Get returns the current value of a ADC pin, in the range 0..0xffff.
func (a ADC) Get() uint16 {
bus := a.getADCBus()
ch := a.getADCChannel()
for bus.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_INPUTCTRL) {
}
// Selection for the positive ADC input channel
bus.INPUTCTRL.ClearBits(sam.ADC_INPUTCTRL_MUXPOS_Msk)
for bus.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_ENABLE) {
}
bus.INPUTCTRL.SetBits((uint16(ch) & sam.ADC_INPUTCTRL_MUXPOS_Msk) << sam.ADC_INPUTCTRL_MUXPOS_Pos)
for bus.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_ENABLE) {
}
// Enable ADC
bus.CTRLA.SetBits(sam.ADC_CTRLA_ENABLE)
for bus.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_ENABLE) {
}
// Start conversion
bus.SWTRIG.SetBits(sam.ADC_SWTRIG_START)
for !bus.INTFLAG.HasBits(sam.ADC_INTFLAG_RESRDY) {
}
// Clear the Data Ready flag
bus.INTFLAG.ClearBits(sam.ADC_INTFLAG_RESRDY)
for bus.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_ENABLE) {
}
// Start conversion again, since first conversion after reference voltage changed is invalid.
bus.SWTRIG.SetBits(sam.ADC_SWTRIG_START)
// Waiting for conversion to complete
for !bus.INTFLAG.HasBits(sam.ADC_INTFLAG_RESRDY) {
}
val := bus.RESULT.Get()
// Disable ADC
for bus.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_ENABLE) {
}
bus.CTRLA.ClearBits(sam.ADC_CTRLA_ENABLE)
for bus.SYNCBUSY.HasBits(sam.ADC_SYNCBUSY_ENABLE) {
}
// scales to 16-bit result
switch (bus.CTRLB.Get() & sam.ADC_CTRLB_RESSEL_Msk) >> sam.ADC_CTRLB_RESSEL_Pos {
case sam.ADC_CTRLB_RESSEL_8BIT:
val = val << 8
case sam.ADC_CTRLB_RESSEL_10BIT:
val = val << 6
case sam.ADC_CTRLB_RESSEL_16BIT:
val = val << 4
case sam.ADC_CTRLB_RESSEL_12BIT:
val = val << 4
}
return val
}
func (a ADC) getADCBus() *sam.ADC_Type {
if (a.Pin >= PB04 && a.Pin <= PB07) || (a.Pin >= PC00) {
return sam.ADC1
}
return sam.ADC0
}
func (a ADC) getADCChannel() uint8 {
switch a.Pin {
case PA02:
return 0
case PB08:
return 2
case PB09:
return 3
case PA04:
return 4
case PA05:
return 5
case PA06:
return 6
case PA07:
return 7
case PB00:
return 12
case PB01:
return 13
case PB02:
return 14
case PB03:
return 15
case PA09:
return 17
case PA11:
return 19
case PB04:
return 6
case PB05:
return 7
case PB06:
return 8
case PB07:
return 9
case PC00:
return 10
case PC01:
return 11
case PC02:
return 4
case PC03:
return 5
case PC30:
return 12
case PC31:
return 13
case PD00:
return 14
case PD01:
return 15
default:
panic("Invalid ADC pin")
}
}
// UART on the SAMD51.
type UART struct {
Buffer *RingBuffer
Bus *sam.SERCOM_USART_INT_Type
SERCOM uint8
Interrupt interrupt.Interrupt // RXC interrupt
}
var (
// UART0 is actually a USB CDC interface.
UART0 = USBCDC{Buffer: NewRingBuffer()}
)
const (
sampleRate16X = 16
lsbFirst = 1
)
// Configure the UART.
func (uart UART) Configure(config UARTConfig) error {
// Default baud rate to 115200.
if config.BaudRate == 0 {
config.BaudRate = 115200
}
// determine pins
if config.TX == 0 && config.RX == 0 {
// use default pins
config.TX = UART_TX_PIN
config.RX = UART_RX_PIN
}
// Determine transmit pinout.
txPinMode, txPad, ok := findPinPadMapping(uart.SERCOM, config.TX)
if !ok {
return ErrInvalidOutputPin
}
var txPinOut uint32
// See CTRLA.RXPO bits of the SERCOM USART peripheral (page 945-946) for how
// pads are mapped to pinout values.
switch txPad {
case 0:
txPinOut = 0
default:
// TODO: flow control (RTS/CTS)
return ErrInvalidOutputPin
}
// Determine receive pinout.
rxPinMode, rxPad, ok := findPinPadMapping(uart.SERCOM, config.RX)
if !ok {
return ErrInvalidInputPin
}
// As you can see in the CTRLA.RXPO bits of the SERCOM USART peripheral
// (page 945), input pins are mapped directly.
rxPinOut := rxPad
// configure pins
config.TX.Configure(PinConfig{Mode: txPinMode})
config.RX.Configure(PinConfig{Mode: rxPinMode})
// reset SERCOM
uart.Bus.CTRLA.SetBits(sam.SERCOM_USART_INT_CTRLA_SWRST)
for uart.Bus.CTRLA.HasBits(sam.SERCOM_USART_INT_CTRLA_SWRST) ||
uart.Bus.SYNCBUSY.HasBits(sam.SERCOM_USART_INT_SYNCBUSY_SWRST) {
}
// set UART mode/sample rate
// SERCOM_USART_CTRLA_MODE(mode) |
// SERCOM_USART_CTRLA_SAMPR(sampleRate);
// sam.SERCOM_USART_CTRLA_MODE_USART_INT_CLK = 1?
uart.Bus.CTRLA.Set((1 << sam.SERCOM_USART_INT_CTRLA_MODE_Pos) |
(1 << sam.SERCOM_USART_INT_CTRLA_SAMPR_Pos)) // sample rate of 16x
// Set baud rate
uart.SetBaudRate(config.BaudRate)
// setup UART frame
// SERCOM_USART_CTRLA_FORM( (parityMode == SERCOM_NO_PARITY ? 0 : 1) ) |
// dataOrder << SERCOM_USART_CTRLA_DORD_Pos;
uart.Bus.CTRLA.SetBits((0 << sam.SERCOM_USART_INT_CTRLA_FORM_Pos) | // no parity
(lsbFirst << sam.SERCOM_USART_INT_CTRLA_DORD_Pos)) // data order
// set UART stop bits/parity
// SERCOM_USART_CTRLB_CHSIZE(charSize) |
// nbStopBits << SERCOM_USART_CTRLB_SBMODE_Pos |
// (parityMode == SERCOM_NO_PARITY ? 0 : parityMode) << SERCOM_USART_CTRLB_PMODE_Pos; //If no parity use default value
uart.Bus.CTRLB.SetBits((0 << sam.SERCOM_USART_INT_CTRLB_CHSIZE_Pos) | // 8 bits is 0
(0 << sam.SERCOM_USART_INT_CTRLB_SBMODE_Pos) | // 1 stop bit is zero
(0 << sam.SERCOM_USART_INT_CTRLB_PMODE_Pos)) // no parity
// set UART pads. This is not same as pins...
// SERCOM_USART_CTRLA_TXPO(txPad) |
// SERCOM_USART_CTRLA_RXPO(rxPad);
uart.Bus.CTRLA.SetBits((txPinOut << sam.SERCOM_USART_INT_CTRLA_TXPO_Pos) |
(rxPinOut << sam.SERCOM_USART_INT_CTRLA_RXPO_Pos))
// Enable Transceiver and Receiver
//sercom->USART.CTRLB.reg |= SERCOM_USART_CTRLB_TXEN | SERCOM_USART_CTRLB_RXEN ;
uart.Bus.CTRLB.SetBits(sam.SERCOM_USART_INT_CTRLB_TXEN | sam.SERCOM_USART_INT_CTRLB_RXEN)
// Enable USART1 port.
// sercom->USART.CTRLA.bit.ENABLE = 0x1u;
uart.Bus.CTRLA.SetBits(sam.SERCOM_USART_INT_CTRLA_ENABLE)
for uart.Bus.SYNCBUSY.HasBits(sam.SERCOM_USART_INT_SYNCBUSY_ENABLE) {
}
// setup interrupt on receive
uart.Bus.INTENSET.Set(sam.SERCOM_USART_INT_INTENSET_RXC)
// Enable RX IRQ.
// This is a small note at the bottom of the NVIC section of the datasheet:
// > The integer number specified in the source refers to the respective bit
// > position in the INTFLAG register of respective peripheral.
// Therefore, if we only need to listen to the RXC interrupt source (in bit
// position 2), we only need interrupt source 2 for this SERCOM device.
uart.Interrupt.Enable()
return nil
}
// SetBaudRate sets the communication speed for the UART.
func (uart UART) SetBaudRate(br uint32) {
// Asynchronous fractional mode (Table 24-2 in datasheet)
// BAUD = fref / (sampleRateValue * fbaud)
// (multiply by 8, to calculate fractional piece)
// uint32_t baudTimes8 = (SystemCoreClock * 8) / (16 * baudrate);
baud := (SERCOM_FREQ_REF * 8) / (sampleRate16X * br)
// sercom->USART.BAUD.FRAC.FP = (baudTimes8 % 8);
// sercom->USART.BAUD.FRAC.BAUD = (baudTimes8 / 8);
uart.Bus.BAUD.Set(uint16(((baud % 8) << sam.SERCOM_USART_INT_BAUD_FRAC_MODE_FP_Pos) |
((baud / 8) << sam.SERCOM_USART_INT_BAUD_FRAC_MODE_BAUD_Pos)))
}
// WriteByte writes a byte of data to the UART.
func (uart UART) WriteByte(c byte) error {
// wait until ready to receive
for !uart.Bus.INTFLAG.HasBits(sam.SERCOM_USART_INT_INTFLAG_DRE) {
}
uart.Bus.DATA.Set(uint32(c))
return nil
}
func (uart *UART) handleInterrupt(interrupt.Interrupt) {
// should reset IRQ
uart.Receive(byte((uart.Bus.DATA.Get() & 0xFF)))
uart.Bus.INTFLAG.SetBits(sam.SERCOM_USART_INT_INTFLAG_RXC)
}
// I2C on the SAMD51.
type I2C struct {
Bus *sam.SERCOM_I2CM_Type
SERCOM uint8
}
// I2CConfig is used to store config info for I2C.
type I2CConfig struct {
Frequency uint32
SCL Pin
SDA Pin
}
const (
// SERCOM_FREQ_REF is always reference frequency on SAMD51 regardless of CPU speed.
SERCOM_FREQ_REF = 48000000
// Default rise time in nanoseconds, based on 4.7K ohm pull up resistors
riseTimeNanoseconds = 125
// wire bus states
wireUnknownState = 0
wireIdleState = 1
wireOwnerState = 2
wireBusyState = 3
// wire commands
wireCmdNoAction = 0
wireCmdRepeatStart = 1
wireCmdRead = 2
wireCmdStop = 3
)
const i2cTimeout = 1000
// Configure is intended to setup the I2C interface.
func (i2c *I2C) Configure(config I2CConfig) error {
// Default I2C bus speed is 100 kHz.
if config.Frequency == 0 {
config.Frequency = TWI_FREQ_100KHZ
}
// Use default I2C pins if not set.
if config.SDA == 0 && config.SCL == 0 {
config.SDA = SDA_PIN
config.SCL = SCL_PIN
}
sclPinMode, sclPad, ok := findPinPadMapping(i2c.SERCOM, config.SCL)
if !ok || sclPad != 1 {
// SCL must be on pad 1, according to section 36.4 of the datasheet.
// Note: this is not an exhaustive test for I2C support on the pin: not
// all pins support I2C.
return ErrInvalidClockPin
}
sdaPinMode, sdaPad, ok := findPinPadMapping(i2c.SERCOM, config.SDA)
if !ok || sdaPad != 0 {
// SDA must be on pad 0, according to section 36.4 of the datasheet.
// Note: this is not an exhaustive test for I2C support on the pin: not
// all pins support I2C.
return ErrInvalidDataPin
}
// reset SERCOM
i2c.Bus.CTRLA.SetBits(sam.SERCOM_I2CM_CTRLA_SWRST)
for i2c.Bus.CTRLA.HasBits(sam.SERCOM_I2CM_CTRLA_SWRST) ||
i2c.Bus.SYNCBUSY.HasBits(sam.SERCOM_I2CM_SYNCBUSY_SWRST) {
}
// Set i2c controller mode
//SERCOM_I2CM_CTRLA_MODE( I2C_MASTER_OPERATION )
// sam.SERCOM_I2CM_CTRLA_MODE_I2C_MASTER = 5?
i2c.Bus.CTRLA.Set(5 << sam.SERCOM_I2CM_CTRLA_MODE_Pos) // |
i2c.SetBaudRate(config.Frequency)
// Enable I2CM port.
// sercom->USART.CTRLA.bit.ENABLE = 0x1u;
i2c.Bus.CTRLA.SetBits(sam.SERCOM_I2CM_CTRLA_ENABLE)
for i2c.Bus.SYNCBUSY.HasBits(sam.SERCOM_I2CM_SYNCBUSY_ENABLE) {
}
// set bus idle mode
i2c.Bus.STATUS.SetBits(wireIdleState << sam.SERCOM_I2CM_STATUS_BUSSTATE_Pos)
for i2c.Bus.SYNCBUSY.HasBits(sam.SERCOM_I2CM_SYNCBUSY_SYSOP) {
}
// enable pins
config.SDA.Configure(PinConfig{Mode: sdaPinMode})
config.SCL.Configure(PinConfig{Mode: sclPinMode})
return nil
}
// SetBaudRate sets the communication speed for the I2C.
func (i2c *I2C) SetBaudRate(br uint32) {
// Synchronous arithmetic baudrate, via Adafruit SAMD51 implementation:
// sercom->I2CM.BAUD.bit.BAUD = SERCOM_FREQ_REF / ( 2 * baudrate) - 1 ;
baud := SERCOM_FREQ_REF/(2*br) - 1
i2c.Bus.BAUD.Set(baud)
}
// Tx does a single I2C transaction at the specified address.
// It clocks out the given address, writes the bytes in w, reads back len(r)
// bytes and stores them in r, and generates a stop condition on the bus.
func (i2c *I2C) Tx(addr uint16, w, r []byte) error {
var err error
if len(w) != 0 {
// send start/address for write
i2c.sendAddress(addr, true)
// wait until transmission complete
timeout := i2cTimeout
for !i2c.Bus.INTFLAG.HasBits(sam.SERCOM_I2CM_INTFLAG_MB) {
timeout--
if timeout == 0 {
return errI2CWriteTimeout
}
}
// ACK received (0: ACK, 1: NACK)
if i2c.Bus.STATUS.HasBits(sam.SERCOM_I2CM_STATUS_RXNACK) {
return errI2CAckExpected
}
// write data
for _, b := range w {
err = i2c.WriteByte(b)
if err != nil {
return err
}
}
err = i2c.signalStop()
if err != nil {
return err
}
}
if len(r) != 0 {
// send start/address for read
i2c.sendAddress(addr, false)
// wait transmission complete
for !i2c.Bus.INTFLAG.HasBits(sam.SERCOM_I2CM_INTFLAG_SB) {
// If the peripheral NACKS the address, the MB bit will be set.
// In that case, send a stop condition and return error.
if i2c.Bus.INTFLAG.HasBits(sam.SERCOM_I2CM_INTFLAG_MB) {
i2c.Bus.CTRLB.SetBits(wireCmdStop << sam.SERCOM_I2CM_CTRLB_CMD_Pos) // Stop condition
return errI2CAckExpected
}
}
// ACK received (0: ACK, 1: NACK)
if i2c.Bus.STATUS.HasBits(sam.SERCOM_I2CM_STATUS_RXNACK) {
return errI2CAckExpected
}
// read first byte
r[0] = i2c.readByte()
for i := 1; i < len(r); i++ {
// Send an ACK
i2c.Bus.CTRLB.ClearBits(sam.SERCOM_I2CM_CTRLB_ACKACT)
i2c.signalRead()
// Read data and send the ACK
r[i] = i2c.readByte()
}
// Send NACK to end transmission
i2c.Bus.CTRLB.SetBits(sam.SERCOM_I2CM_CTRLB_ACKACT)
err = i2c.signalStop()
if err != nil {
return err
}
}
return nil
}
// WriteByte writes a single byte to the I2C bus.
func (i2c *I2C) WriteByte(data byte) error {
// Send data byte
i2c.Bus.DATA.Set(data)
// wait until transmission successful
timeout := i2cTimeout
for !i2c.Bus.INTFLAG.HasBits(sam.SERCOM_I2CM_INTFLAG_MB) {
// check for bus error
if i2c.Bus.STATUS.HasBits(sam.SERCOM_I2CM_STATUS_BUSERR) {
return errI2CBusError
}
timeout--
if timeout == 0 {
return errI2CWriteTimeout
}
}
if i2c.Bus.STATUS.HasBits(sam.SERCOM_I2CM_STATUS_RXNACK) {
return errI2CAckExpected
}
return nil
}
// sendAddress sends the address and start signal
func (i2c *I2C) sendAddress(address uint16, write bool) error {
data := (address << 1)
if !write {
data |= 1 // set read flag
}
// wait until bus ready
timeout := i2cTimeout
for !i2c.Bus.STATUS.HasBits(wireIdleState<<sam.SERCOM_I2CM_STATUS_BUSSTATE_Pos) &&
!i2c.Bus.STATUS.HasBits(wireOwnerState<<sam.SERCOM_I2CM_STATUS_BUSSTATE_Pos) {
timeout--
if timeout == 0 {
return errI2CBusReadyTimeout
}
}
i2c.Bus.ADDR.Set(uint32(data))
return nil
}
func (i2c *I2C) signalStop() error {
i2c.Bus.CTRLB.SetBits(wireCmdStop << sam.SERCOM_I2CM_CTRLB_CMD_Pos) // Stop command
timeout := i2cTimeout
for i2c.Bus.SYNCBUSY.HasBits(sam.SERCOM_I2CM_SYNCBUSY_SYSOP) {
timeout--
if timeout == 0 {
return errI2CSignalStopTimeout
}
}
return nil
}
func (i2c *I2C) signalRead() error {
i2c.Bus.CTRLB.SetBits(wireCmdRead << sam.SERCOM_I2CM_CTRLB_CMD_Pos) // Read command
timeout := i2cTimeout
for i2c.Bus.SYNCBUSY.HasBits(sam.SERCOM_I2CM_SYNCBUSY_SYSOP) {
timeout--
if timeout == 0 {
return errI2CSignalReadTimeout
}
}
return nil
}
func (i2c *I2C) readByte() byte {
for !i2c.Bus.INTFLAG.HasBits(sam.SERCOM_I2CM_INTFLAG_SB) {
}
return byte(i2c.Bus.DATA.Get())
}
// SPI
type SPI struct {
Bus *sam.SERCOM_SPIM_Type
SERCOM uint8
}
// SPIConfig is used to store config info for SPI.
type SPIConfig struct {
Frequency uint32
SCK Pin
SDO Pin
SDI Pin
LSBFirst bool
Mode uint8
}
// Configure is intended to setup the SPI interface.
func (spi SPI) Configure(config SPIConfig) error {
// Use default pins if not set.
if config.SCK == 0 && config.SDO == 0 && config.SDI == 0 {
config.SCK = SPI0_SCK_PIN
config.SDO = SPI0_SDO_PIN
config.SDI = SPI0_SDI_PIN
}
// set default frequency
if config.Frequency == 0 {
config.Frequency = 4000000
}
// Determine the input pinout (for SDI).
var dataInPinout uint32
var SDIPinMode PinMode
if config.SDI != NoPin {
var ok bool
SDIPinMode, dataInPinout, ok = findPinPadMapping(spi.SERCOM, config.SDI)
if !ok {
return ErrInvalidInputPin
}
}
// Determine the output pinout (for SDO/SCK).
// See DOPO field in the CTRLA register on page 986 of the datasheet.
var dataOutPinout uint32
sckPinMode, sckPad, ok := findPinPadMapping(spi.SERCOM, config.SCK)
if !ok || sckPad != 1 {
// SCK pad must always be 1
return ErrInvalidOutputPin
}
SDOPinMode, SDOPad, ok := findPinPadMapping(spi.SERCOM, config.SDO)
if !ok {
return ErrInvalidOutputPin
}
switch SDOPad {
case 0:
dataOutPinout = 0x0
case 3:
dataOutPinout = 0x2
default:
return ErrInvalidOutputPin
}
// Disable SPI port.
spi.Bus.CTRLA.ClearBits(sam.SERCOM_SPIM_CTRLA_ENABLE)
for spi.Bus.SYNCBUSY.HasBits(sam.SERCOM_SPIM_SYNCBUSY_ENABLE) {
}
// enable pins
config.SCK.Configure(PinConfig{Mode: sckPinMode})
config.SDO.Configure(PinConfig{Mode: SDOPinMode})
if config.SDI != NoPin {
config.SDI.Configure(PinConfig{Mode: SDIPinMode})
}
// reset SERCOM
spi.Bus.CTRLA.SetBits(sam.SERCOM_SPIM_CTRLA_SWRST)
for spi.Bus.CTRLA.HasBits(sam.SERCOM_SPIM_CTRLA_SWRST) ||
spi.Bus.SYNCBUSY.HasBits(sam.SERCOM_SPIM_SYNCBUSY_SWRST) {
}
// set bit transfer order
dataOrder := uint32(0)
if config.LSBFirst {
dataOrder = 1
}
// Set SPI controller
// SERCOM_SPIM_CTRLA_MODE_SPI_MASTER = 3
spi.Bus.CTRLA.Set((3 << sam.SERCOM_SPIM_CTRLA_MODE_Pos) |
(dataOutPinout << sam.SERCOM_SPIM_CTRLA_DOPO_Pos) |
(dataInPinout << sam.SERCOM_SPIM_CTRLA_DIPO_Pos) |
(dataOrder << sam.SERCOM_SPIM_CTRLA_DORD_Pos))
spi.Bus.CTRLB.SetBits((0 << sam.SERCOM_SPIM_CTRLB_CHSIZE_Pos) | // 8bit char size
sam.SERCOM_SPIM_CTRLB_RXEN) // receive enable
for spi.Bus.SYNCBUSY.HasBits(sam.SERCOM_SPIM_SYNCBUSY_CTRLB) {
}
// set mode
switch config.Mode {
case 0:
spi.Bus.CTRLA.ClearBits(sam.SERCOM_SPIM_CTRLA_CPHA)
spi.Bus.CTRLA.ClearBits(sam.SERCOM_SPIM_CTRLA_CPOL)
case 1:
spi.Bus.CTRLA.SetBits(sam.SERCOM_SPIM_CTRLA_CPHA)
spi.Bus.CTRLA.ClearBits(sam.SERCOM_SPIM_CTRLA_CPOL)
case 2:
spi.Bus.CTRLA.ClearBits(sam.SERCOM_SPIM_CTRLA_CPHA)
spi.Bus.CTRLA.SetBits(sam.SERCOM_SPIM_CTRLA_CPOL)
case 3:
spi.Bus.CTRLA.SetBits(sam.SERCOM_SPIM_CTRLA_CPHA | sam.SERCOM_SPIM_CTRLA_CPOL)
default: // to mode 0
spi.Bus.CTRLA.ClearBits(sam.SERCOM_SPIM_CTRLA_CPHA)
spi.Bus.CTRLA.ClearBits(sam.SERCOM_SPIM_CTRLA_CPOL)
}
// Set synch speed for SPI
baudRate := SERCOM_FREQ_REF / (2 * config.Frequency)
if baudRate > 0 {
baudRate--
}
spi.Bus.BAUD.Set(uint8(baudRate))
// Enable SPI port.
spi.Bus.CTRLA.SetBits(sam.SERCOM_SPIM_CTRLA_ENABLE)
for spi.Bus.SYNCBUSY.HasBits(sam.SERCOM_SPIM_SYNCBUSY_ENABLE) {
}
return nil
}
// Transfer writes/reads a single byte using the SPI interface.
func (spi SPI) Transfer(w byte) (byte, error) {
// write data
spi.Bus.DATA.Set(uint32(w))
// wait for receive
for !spi.Bus.INTFLAG.HasBits(sam.SERCOM_SPIM_INTFLAG_RXC) {
}
// return data
return byte(spi.Bus.DATA.Get()), nil
}
var (
ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
)
// Tx handles read/write operation for SPI interface. Since SPI is a syncronous write/read
// interface, there must always be the same number of bytes written as bytes read.
// The Tx method knows about this, and offers a few different ways of calling it.
//
// This form sends the bytes in tx buffer, putting the resulting bytes read into the rx buffer.
// Note that the tx and rx buffers must be the same size:
//
// spi.Tx(tx, rx)
//
// This form sends the tx buffer, ignoring the result. Useful for sending "commands" that return zeros
// until all the bytes in the command packet have been received:
//
// spi.Tx(tx, nil)
//
// This form sends zeros, putting the result into the rx buffer. Good for reading a "result packet":
//
// spi.Tx(nil, rx)
//
func (spi SPI) Tx(w, r []byte) error {
switch {
case w == nil:
// read only, so write zero and read a result.
spi.rx(r)
case r == nil:
// write only
spi.tx(w)
default:
// write/read
if len(w) != len(r) {
return ErrTxInvalidSliceSize
}
spi.txrx(w, r)
}
return nil
}
func (spi SPI) tx(tx []byte) {
for i := 0; i < len(tx); i++ {
for !spi.Bus.INTFLAG.HasBits(sam.SERCOM_SPIM_INTFLAG_DRE) {
}
spi.Bus.DATA.Set(uint32(tx[i]))
}
for !spi.Bus.INTFLAG.HasBits(sam.SERCOM_SPIM_INTFLAG_TXC) {
}
// read to clear RXC register
for spi.Bus.INTFLAG.HasBits(sam.SERCOM_SPIM_INTFLAG_RXC) {
spi.Bus.DATA.Get()
}
}
func (spi SPI) rx(rx []byte) {
spi.Bus.DATA.Set(0)
for !spi.Bus.INTFLAG.HasBits(sam.SERCOM_SPIM_INTFLAG_DRE) {
}
for i := 1; i < len(rx); i++ {
spi.Bus.DATA.Set(0)
for !spi.Bus.INTFLAG.HasBits(sam.SERCOM_SPIM_INTFLAG_RXC) {
}
rx[i-1] = byte(spi.Bus.DATA.Get())
}
for !spi.Bus.INTFLAG.HasBits(sam.SERCOM_SPIM_INTFLAG_RXC) {
}
rx[len(rx)-1] = byte(spi.Bus.DATA.Get())
}
func (spi SPI) txrx(tx, rx []byte) {
spi.Bus.DATA.Set(uint32(tx[0]))
for !spi.Bus.INTFLAG.HasBits(sam.SERCOM_SPIM_INTFLAG_DRE) {
}
for i := 1; i < len(rx); i++ {
spi.Bus.DATA.Set(uint32(tx[i]))
for !spi.Bus.INTFLAG.HasBits(sam.SERCOM_SPIM_INTFLAG_RXC) {
}
rx[i-1] = byte(spi.Bus.DATA.Get())
}
for !spi.Bus.INTFLAG.HasBits(sam.SERCOM_SPIM_INTFLAG_RXC) {
}
rx[len(rx)-1] = byte(spi.Bus.DATA.Get())
}
// The QSPI peripheral on ATSAMD51 is only available on the following pins
const (
QSPI_SCK = PB10
QSPI_CS = PB11
QSPI_DATA0 = PA08
QSPI_DATA1 = PA09
QSPI_DATA2 = PA10
QSPI_DATA3 = PA11
)
// TCC is one timer peripheral, which consists of a counter and multiple output
// channels (that can be connected to actual pins). You can set the frequency
// using SetPeriod, but only for all the channels in this timer peripheral at
// once.
type TCC sam.TCC_Type
//go:inline
func (tcc *TCC) timer() *sam.TCC_Type {
return (*sam.TCC_Type)(tcc)
}
// Configure enables and configures this TCC.
func (tcc *TCC) Configure(config PWMConfig) error {
// Enable the TCC clock to be able to use the TCC.
tcc.configureClock()
// Disable timer (if it was enabled). This is necessary because
// tcc.setPeriod may want to change the prescaler bits in CTRLA, which is
// only allowed when the TCC is disabled.
tcc.timer().CTRLA.ClearBits(sam.TCC_CTRLA_ENABLE)
// Use "Normal PWM" (single-slope PWM)
tcc.timer().WAVE.Set(sam.TCC_WAVE_WAVEGEN_NPWM)
// Wait for synchronization of all changed registers.
for tcc.timer().SYNCBUSY.Get() != 0 {
}
// Set the period and prescaler.
err := tcc.setPeriod(config.Period, true)
// Enable the timer.
tcc.timer().CTRLA.SetBits(sam.TCC_CTRLA_ENABLE)
// Wait for synchronization of all changed registers.
for tcc.timer().SYNCBUSY.Get() != 0 {
}
// Return any error that might have occured in the tcc.setPeriod call.
return err
}
// SetPeriod updates the period of this TCC peripheral.
// To set a particular frequency, use the following formula:
//
// period = 1e9 / frequency
//
// If you use a period of 0, a period that works well for LEDs will be picked.
//
// SetPeriod will not change the prescaler, but also won't change the current
// value in any of the channels. This means that you may need to update the
// value for the particular channel.
//
// Note that you cannot pick any arbitrary period after the TCC peripheral has
// been configured. If you want to switch between frequencies, pick the lowest
// frequency (longest period) once when calling Configure and adjust the
// frequency here as needed.
func (tcc *TCC) SetPeriod(period uint64) error {
return tcc.setPeriod(period, false)
}
// setPeriod sets the period of this TCC, possibly updating the prescaler as
// well. The prescaler can only modified when the TCC is disabled, that is, in
// the Configure function.
func (tcc *TCC) setPeriod(period uint64, updatePrescaler bool) error {
var top uint64
if period == 0 {
// Make sure the TOP value is at 0xffff (enough for a 16-bit timer).
top = 0xffff
} else {
// The formula below calculates the following formula, optimized:
// period * (120e6 / 1e9)
// This assumes that the chip is running from generic clock generator 0
// at 120MHz.
top = period * 3 / 25
}
maxTop := uint64(0xffff)
if tcc.timer() == sam.TCC0 || tcc.timer() == sam.TCC1 {
// Only TCC0 and TCC1 are 24-bit timers, the rest are 16-bit.
maxTop = 0xffffff
}
if updatePrescaler {
// This function was called during Configure(), with the timer disabled.
// Note that updating the prescaler can only happen while the peripheral
// is disabled.
var prescaler uint32
switch {
case top <= maxTop:
prescaler = sam.TCC_CTRLA_PRESCALER_DIV1
case top/2 <= maxTop:
prescaler = sam.TCC_CTRLA_PRESCALER_DIV2
top = top / 2
case top/4 <= maxTop:
prescaler = sam.TCC_CTRLA_PRESCALER_DIV4
top = top / 4
case top/8 <= maxTop:
prescaler = sam.TCC_CTRLA_PRESCALER_DIV8
top = top / 8
case top/16 <= maxTop:
prescaler = sam.TCC_CTRLA_PRESCALER_DIV16
top = top / 16
case top/64 <= maxTop:
prescaler = sam.TCC_CTRLA_PRESCALER_DIV64
top = top / 64
case top/256 <= maxTop:
prescaler = sam.TCC_CTRLA_PRESCALER_DIV256
top = top / 256
case top/1024 <= maxTop:
prescaler = sam.TCC_CTRLA_PRESCALER_DIV1024
top = top / 1024
default:
return ErrPWMPeriodTooLong
}
tcc.timer().CTRLA.Set((tcc.timer().CTRLA.Get() &^ sam.TCC_CTRLA_PRESCALER_Msk) | (prescaler << sam.TCC_CTRLA_PRESCALER_Pos))
} else {
// Do not update the prescaler, but use the already-configured
// prescaler. This is the normal SetPeriod case, where the prescaler
// must not be changed.
prescaler := (tcc.timer().CTRLA.Get() & sam.TCC_CTRLA_PRESCALER_Msk) >> sam.TCC_CTRLA_PRESCALER_Pos
switch prescaler {
case sam.TCC_CTRLA_PRESCALER_DIV1:
top /= 1 // no-op
case sam.TCC_CTRLA_PRESCALER_DIV2:
top /= 2
case sam.TCC_CTRLA_PRESCALER_DIV4:
top /= 4
case sam.TCC_CTRLA_PRESCALER_DIV8:
top /= 8
case sam.TCC_CTRLA_PRESCALER_DIV16:
top /= 16
case sam.TCC_CTRLA_PRESCALER_DIV64:
top /= 64
case sam.TCC_CTRLA_PRESCALER_DIV256:
top /= 256
case sam.TCC_CTRLA_PRESCALER_DIV1024:
top /= 1024
default:
// unreachable
}
if top > maxTop {
return ErrPWMPeriodTooLong
}
}
// Set the period (the counter top).
tcc.timer().PER.Set(uint32(top) - 1)
// Wait for synchronization of CTRLA.PRESCALER and PER registers.
for tcc.timer().SYNCBUSY.Get() != 0 {
}
return nil
}
// Top returns the current counter top, for use in duty cycle calculation. It
// will only change with a call to Configure or SetPeriod, otherwise it is
// constant.
//
// The value returned here is hardware dependent. In general, it's best to treat
// it as an opaque value that can be divided by some number and passed to
// tcc.Set (see tcc.Set for more information).
func (tcc *TCC) Top() uint32 {
return tcc.timer().PER.Get() + 1
}
// Counter returns the current counter value of the timer in this TCC
// peripheral. It may be useful for debugging.
func (tcc *TCC) Counter() uint32 {
tcc.timer().CTRLBSET.Set(sam.TCC_CTRLBSET_CMD_READSYNC << sam.TCC_CTRLBSET_CMD_Pos)
for tcc.timer().SYNCBUSY.Get() != 0 {
}
return tcc.timer().COUNT.Get()
}
// Constants that encode a TCC number and WO number together in a single byte.
const (
pinTCC0 = 1 << 4 // keep the value 0 usable as "no value"
pinTCC1 = 2 << 4
pinTCC2 = 3 << 4
pinTCC3 = 4 << 4
pinTCC4 = 5 << 4
pinTCC0_0 = pinTCC0 | 0
pinTCC0_1 = pinTCC0 | 1
pinTCC0_2 = pinTCC0 | 2
pinTCC0_3 = pinTCC0 | 3
pinTCC0_4 = pinTCC0 | 4
pinTCC0_5 = pinTCC0 | 5
pinTCC0_6 = pinTCC0 | 6
pinTCC1_0 = pinTCC1 | 0
pinTCC1_2 = pinTCC1 | 2
pinTCC1_4 = pinTCC1 | 4
pinTCC1_6 = pinTCC1 | 6
pinTCC2_0 = pinTCC2 | 0
pinTCC2_2 = pinTCC2 | 2
pinTCC3_0 = pinTCC3 | 0
pinTCC4_0 = pinTCC4 | 0
)
// This is a copy of columns F and G (the TCC columns) of table 6-1 in the
// datasheet:
// http://ww1.microchip.com/downloads/en/DeviceDoc/60001507E.pdf
// For example, "TCC0/WO[2]" is converted to pinTCC0_2.
// Only the even pin numbers are stored here. The odd pin numbers are left out,
// because their PWM output can be determined from the even number: just add one
// to the wave output (WO) number.
var pinTimerMapping = [...]struct{ F, G uint8 }{
// page 33
PC04 / 2: {pinTCC0_0, 0},
PA08 / 2: {pinTCC0_0, pinTCC1_4},
PA10 / 2: {pinTCC0_2, pinTCC1_6},
PB10 / 2: {pinTCC0_4, pinTCC1_0},
PB12 / 2: {pinTCC3_0, pinTCC0_0},
PB14 / 2: {pinTCC4_0, pinTCC0_2},
PD08 / 2: {pinTCC0_1, 0},
PD10 / 2: {pinTCC0_3, 0},
PD12 / 2: {pinTCC0_5, 0},
PC10 / 2: {pinTCC0_0, pinTCC1_4},
// page 34
PC12 / 2: {pinTCC0_2, pinTCC1_6},
PC14 / 2: {pinTCC0_4, pinTCC1_0},
PA12 / 2: {pinTCC0_6, pinTCC1_2},
PA14 / 2: {pinTCC2_0, pinTCC1_2},
PA16 / 2: {pinTCC1_0, pinTCC0_4},
PA18 / 2: {pinTCC1_2, pinTCC0_6},
PC16 / 2: {pinTCC0_0, 0},
PC18 / 2: {pinTCC0_2, 0},
PC20 / 2: {pinTCC0_4, 0},
PC22 / 2: {pinTCC0_6, 0},
PD20 / 2: {pinTCC1_0, 0},
PB16 / 2: {pinTCC3_0, pinTCC0_4},
PB18 / 2: {pinTCC1_0, 0},
// page 35
PB20 / 2: {pinTCC1_2, 0},
PA20 / 2: {pinTCC1_4, pinTCC0_0},
PA22 / 2: {pinTCC1_6, pinTCC0_2},
PA24 / 2: {pinTCC2_2, 0},
PB26 / 2: {pinTCC1_2, 0},
PB28 / 2: {pinTCC1_4, 0},
PA30 / 2: {pinTCC2_0, 0},
// page 36
PB30 / 2: {pinTCC4_0, pinTCC0_6},
PB02 / 2: {pinTCC2_2, 0},
}
// findPinPadMapping returns the pin mode (PinTCCF or PinTCCG) and the channel
// number for a given timer and pin. A zero PinMode is returned if no mapping
// could be found.
func findPinTimerMapping(timer uint8, pin Pin) (PinMode, uint8) {
if int(pin/2) >= len(pinTimerMapping) {
return 0, 0 // invalid pin number
}
mapping := pinTimerMapping[pin/2]
// Check for column F in the datasheet.
if mapping.F>>4-1 == timer {
return PinTCCF, mapping.F&0x0f + uint8(pin)&1
}
// Check for column G in the datasheet.
if mapping.G>>4-1 == timer {
return PinTCCG, mapping.G&0x0f + uint8(pin)&1
}
// Nothing found.
return 0, 0
}
// Channel returns a PWM channel for the given pin. Note that one channel may be
// shared between multiple pins, and so will have the same duty cycle. If this
// is not desirable, look for a different TCC or consider using a different pin.
func (tcc *TCC) Channel(pin Pin) (uint8, error) {
pinMode, woOutput := findPinTimerMapping(tcc.timerNum(), pin)
if pinMode == 0 {
// No pin could be found.
return 0, ErrInvalidOutputPin
}
// Convert from waveform output to channel, assuming WEXCTRL.OTMX equals 0.
// See table 49-4 "Output Matrix Channel Pin Routing Configuration" on page
// 1829 of the datasheet.
// The number of channels varies by TCC instance, hence the need to switch
// over them. For TCC2-4 the number of channels is equal to the number of
// waveform outputs, so the WO number maps directly to the channel number.
// For TCC0 and TCC1 this is not the case so they will need some special
// handling.
channel := woOutput
switch tcc.timer() {
case sam.TCC0:
channel = woOutput % 6
case sam.TCC1:
channel = woOutput % 4
}
// Enable the port multiplexer for pin
pin.setPinCfg(sam.PORT_GROUP_PINCFG_PMUXEN)
// Connect timer/mux to pin.
if pin&1 > 0 {
// odd pin, so save the even pins
val := pin.getPMux() & sam.PORT_GROUP_PMUX_PMUXE_Msk
pin.setPMux(val | uint8(pinMode<<sam.PORT_GROUP_PMUX_PMUXO_Pos))
} else {
// even pin, so save the odd pins
val := pin.getPMux() & sam.PORT_GROUP_PMUX_PMUXO_Msk
pin.setPMux(val | uint8(pinMode<<sam.PORT_GROUP_PMUX_PMUXE_Pos))
}
return channel, nil
}
// SetInverting sets whether to invert the output of this channel.
// Without inverting, a 25% duty cycle would mean the output is high for 25% of
// the time and low for the rest. Inverting flips the output as if a NOT gate
// was placed at the output, meaning that the output would be 25% low and 75%
// high with a duty cycle of 25%.
func (tcc *TCC) SetInverting(channel uint8, inverting bool) {
if inverting {
tcc.timer().WAVE.SetBits(1 << (sam.TCC_WAVE_POL0_Pos + channel))
} else {
tcc.timer().WAVE.ClearBits(1 << (sam.TCC_WAVE_POL0_Pos + channel))
}
// Wait for synchronization of the WAVE register.
for tcc.timer().SYNCBUSY.Get() != 0 {
}
}
// Set updates the channel value. This is used to control the channel duty
// cycle, in other words the fraction of time the channel output is high (or low
// when inverted). For example, to set it to a 25% duty cycle, use:
//
// tcc.Set(channel, tcc.Top() / 4)
//
// tcc.Set(channel, 0) will set the output to low and tcc.Set(channel,
// tcc.Top()) will set the output to high, assuming the output isn't inverted.
func (tcc *TCC) Set(channel uint8, value uint32) {
// Update CCBUF, which provides double buffering. The update is applied on
// the next cycle.
tcc.timer().CCBUF[channel].Set(value)
for tcc.timer().SYNCBUSY.Get() != 0 {
}
}
// USBCDC is the USB CDC aka serial over USB interface on the SAMD21.
type USBCDC struct {
Buffer *RingBuffer
TxIdx volatile.Register8
waitTxc bool
waitTxcRetryCount uint8
sent bool
}
const (
usbcdcTxSizeMask uint8 = 0x3F
usbcdcTxBankMask uint8 = ^usbcdcTxSizeMask
usbcdcTxBank1st uint8 = 0x00
usbcdcTxBank2nd uint8 = usbcdcTxSizeMask + 1
usbcdcTxMaxRetriesAllowed uint8 = 5
)
// Flush flushes buffered data.
func (usbcdc *USBCDC) Flush() error {
if usbLineInfo.lineState > 0 {
idx := usbcdc.TxIdx.Get()
sz := idx & usbcdcTxSizeMask
bk := idx & usbcdcTxBankMask
if 0 < sz {
if usbcdc.waitTxc {
// waiting for the next flush(), because the transmission is not complete
usbcdc.waitTxcRetryCount++
return nil
}
usbcdc.waitTxc = true
usbcdc.waitTxcRetryCount = 0
// set the data
usbEndpointDescriptors[usb_CDC_ENDPOINT_IN].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[usb_CDC_ENDPOINT_IN][bk]))))
if bk == usbcdcTxBank1st {
usbcdc.TxIdx.Set(usbcdcTxBank2nd)
} else {
usbcdc.TxIdx.Set(usbcdcTxBank1st)
}
// clean multi packet size of bytes already sent
usbEndpointDescriptors[usb_CDC_ENDPOINT_IN].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)
// set count of bytes to be sent
usbEndpointDescriptors[usb_CDC_ENDPOINT_IN].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
usbEndpointDescriptors[usb_CDC_ENDPOINT_IN].DeviceDescBank[1].PCKSIZE.SetBits((uint32(sz) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask) << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
// clear transfer complete flag
setEPINTFLAG(usb_CDC_ENDPOINT_IN, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1)
// send data by setting bank ready
setEPSTATUSSET(usb_CDC_ENDPOINT_IN, sam.USB_DEVICE_ENDPOINT_EPSTATUSSET_BK1RDY)
UART0.sent = true
}
}
return nil
}
// WriteByte writes a byte of data to the USB CDC interface.
func (usbcdc *USBCDC) WriteByte(c byte) error {
// Supposedly to handle problem with Windows USB serial ports?
if usbLineInfo.lineState > 0 {
ok := false
for {
mask := interrupt.Disable()
idx := UART0.TxIdx.Get()
if (idx & usbcdcTxSizeMask) < usbcdcTxSizeMask {
udd_ep_in_cache_buffer[usb_CDC_ENDPOINT_IN][idx] = c
UART0.TxIdx.Set(idx + 1)
ok = true
}
interrupt.Restore(mask)
if ok {
break
} else if usbcdcTxMaxRetriesAllowed < UART0.waitTxcRetryCount {
mask := interrupt.Disable()
UART0.waitTxc = false
UART0.waitTxcRetryCount = 0
UART0.TxIdx.Set(0)
usbLineInfo.lineState = 0
interrupt.Restore(mask)
break
} else {
mask := interrupt.Disable()
if UART0.sent {
if UART0.waitTxc {
if (getEPINTFLAG(usb_CDC_ENDPOINT_IN) & sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1) != 0 {
setEPSTATUSCLR(usb_CDC_ENDPOINT_IN, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK1RDY)
setEPINTFLAG(usb_CDC_ENDPOINT_IN, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1)
UART0.waitTxc = false
UART0.Flush()
}
} else {
UART0.Flush()
}
}
interrupt.Restore(mask)
}
}
}
return nil
}
func (usbcdc USBCDC) DTR() bool {
return (usbLineInfo.lineState & usb_CDC_LINESTATE_DTR) > 0
}
func (usbcdc USBCDC) RTS() bool {
return (usbLineInfo.lineState & usb_CDC_LINESTATE_RTS) > 0
}
const (
// these are SAMD51 specific.
usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos = 0
usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask = 0x3FFF
usb_DEVICE_PCKSIZE_SIZE_Pos = 28
usb_DEVICE_PCKSIZE_SIZE_Mask = 0x7
usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos = 14
usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask = 0x3FFF
)
var (
usbEndpointDescriptors [8]usbDeviceDescriptor
udd_ep_in_cache_buffer [7][128]uint8
udd_ep_out_cache_buffer [7][128]uint8
isEndpointHalt = false
isRemoteWakeUpEnabled = false
endPoints = []uint32{usb_ENDPOINT_TYPE_CONTROL,
(usb_ENDPOINT_TYPE_INTERRUPT | usbEndpointIn),
(usb_ENDPOINT_TYPE_BULK | usbEndpointOut),
(usb_ENDPOINT_TYPE_BULK | usbEndpointIn)}
usbConfiguration uint8
usbSetInterface uint8
usbLineInfo = cdcLineInfo{115200, 0x00, 0x00, 0x08, 0x00}
)
// Configure the USB CDC interface. The config is here for compatibility with the UART interface.
func (usbcdc USBCDC) Configure(config UARTConfig) {
// reset USB interface
sam.USB_DEVICE.CTRLA.SetBits(sam.USB_DEVICE_CTRLA_SWRST)
for sam.USB_DEVICE.SYNCBUSY.HasBits(sam.USB_DEVICE_SYNCBUSY_SWRST) ||
sam.USB_DEVICE.SYNCBUSY.HasBits(sam.USB_DEVICE_SYNCBUSY_ENABLE) {
}
sam.USB_DEVICE.DESCADD.Set(uint32(uintptr(unsafe.Pointer(&usbEndpointDescriptors))))
// configure pins
USBCDC_DM_PIN.Configure(PinConfig{Mode: PinCom})
USBCDC_DP_PIN.Configure(PinConfig{Mode: PinCom})
// performs pad calibration from store fuses
handlePadCalibration()
// run in standby
sam.USB_DEVICE.CTRLA.SetBits(sam.USB_DEVICE_CTRLA_RUNSTDBY)
// set full speed
sam.USB_DEVICE.CTRLB.SetBits(sam.USB_DEVICE_CTRLB_SPDCONF_FS << sam.USB_DEVICE_CTRLB_SPDCONF_Pos)
// attach
sam.USB_DEVICE.CTRLB.ClearBits(sam.USB_DEVICE_CTRLB_DETACH)
// enable interrupt for end of reset
sam.USB_DEVICE.INTENSET.SetBits(sam.USB_DEVICE_INTENSET_EORST)
// enable interrupt for start of frame
sam.USB_DEVICE.INTENSET.SetBits(sam.USB_DEVICE_INTENSET_SOF)
// enable USB
sam.USB_DEVICE.CTRLA.SetBits(sam.USB_DEVICE_CTRLA_ENABLE)
// enable IRQ at highest priority
interrupt.New(sam.IRQ_USB_OTHER, handleUSBIRQ).Enable()
interrupt.New(sam.IRQ_USB_SOF_HSOF, handleUSBIRQ).Enable()
interrupt.New(sam.IRQ_USB_TRCPT0, handleUSBIRQ).Enable()
interrupt.New(sam.IRQ_USB_TRCPT1, handleUSBIRQ).Enable()
}
func handlePadCalibration() {
// Load Pad Calibration data from non-volatile memory
// This requires registers that are not included in the SVD file.
// Modeled after defines from samd21g18a.h and nvmctrl.h:
//
// #define NVMCTRL_OTP4 0x00806020
//
// #define USB_FUSES_TRANSN_ADDR (NVMCTRL_OTP4 + 4)
// #define USB_FUSES_TRANSN_Pos 13 /**< \brief (NVMCTRL_OTP4) USB pad Transn calibration */
// #define USB_FUSES_TRANSN_Msk (0x1Fu << USB_FUSES_TRANSN_Pos)
// #define USB_FUSES_TRANSN(value) ((USB_FUSES_TRANSN_Msk & ((value) << USB_FUSES_TRANSN_Pos)))
// #define USB_FUSES_TRANSP_ADDR (NVMCTRL_OTP4 + 4)
// #define USB_FUSES_TRANSP_Pos 18 /**< \brief (NVMCTRL_OTP4) USB pad Transp calibration */
// #define USB_FUSES_TRANSP_Msk (0x1Fu << USB_FUSES_TRANSP_Pos)
// #define USB_FUSES_TRANSP(value) ((USB_FUSES_TRANSP_Msk & ((value) << USB_FUSES_TRANSP_Pos)))
// #define USB_FUSES_TRIM_ADDR (NVMCTRL_OTP4 + 4)
// #define USB_FUSES_TRIM_Pos 23 /**< \brief (NVMCTRL_OTP4) USB pad Trim calibration */
// #define USB_FUSES_TRIM_Msk (0x7u << USB_FUSES_TRIM_Pos)
// #define USB_FUSES_TRIM(value) ((USB_FUSES_TRIM_Msk & ((value) << USB_FUSES_TRIM_Pos)))
//
fuse := *(*uint32)(unsafe.Pointer(uintptr(0x00806020) + 4))
calibTransN := uint16(fuse>>13) & uint16(0x1f)
calibTransP := uint16(fuse>>18) & uint16(0x1f)
calibTrim := uint16(fuse>>23) & uint16(0x7)
if calibTransN == 0x1f {
calibTransN = 5
}
sam.USB_DEVICE.PADCAL.SetBits(calibTransN << sam.USB_DEVICE_PADCAL_TRANSN_Pos)
if calibTransP == 0x1f {
calibTransP = 29
}
sam.USB_DEVICE.PADCAL.SetBits(calibTransP << sam.USB_DEVICE_PADCAL_TRANSP_Pos)
if calibTrim == 0x7 {
calibTransN = 3
}
sam.USB_DEVICE.PADCAL.SetBits(calibTrim << sam.USB_DEVICE_PADCAL_TRIM_Pos)
}
func handleUSBIRQ(interrupt.Interrupt) {
// reset all interrupt flags
flags := sam.USB_DEVICE.INTFLAG.Get()
sam.USB_DEVICE.INTFLAG.Set(flags)
// End of reset
if (flags & sam.USB_DEVICE_INTFLAG_EORST) > 0 {
// Configure control endpoint
initEndpoint(0, usb_ENDPOINT_TYPE_CONTROL)
// Enable Setup-Received interrupt
setEPINTENSET(0, sam.USB_DEVICE_ENDPOINT_EPINTENSET_RXSTP)
usbConfiguration = 0
// ack the End-Of-Reset interrupt
sam.USB_DEVICE.INTFLAG.Set(sam.USB_DEVICE_INTFLAG_EORST)
}
// Start of frame
if (flags & sam.USB_DEVICE_INTFLAG_SOF) > 0 {
UART0.Flush()
// if you want to blink LED showing traffic, this would be the place...
}
// Endpoint 0 Setup interrupt
if getEPINTFLAG(0)&sam.USB_DEVICE_ENDPOINT_EPINTFLAG_RXSTP > 0 {
// ack setup received
setEPINTFLAG(0, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_RXSTP)
// parse setup
setup := newUSBSetup(udd_ep_out_cache_buffer[0][:])
// Clear the Bank 0 ready flag on Control OUT
setEPSTATUSCLR(0, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK0RDY)
usbEndpointDescriptors[0].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
ok := false
if (setup.bmRequestType & usb_REQUEST_TYPE) == usb_REQUEST_STANDARD {
// Standard Requests
ok = handleStandardSetup(setup)
} else {
// Class Interface Requests
if setup.wIndex == usb_CDC_ACM_INTERFACE {
ok = cdcSetup(setup)
}
}
if ok {
// set Bank1 ready
setEPSTATUSSET(0, sam.USB_DEVICE_ENDPOINT_EPSTATUSSET_BK1RDY)
} else {
// Stall endpoint
setEPSTATUSSET(0, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_STALL1)
}
if getEPINTFLAG(0)&sam.USB_DEVICE_ENDPOINT_EPINTFLAG_STALL1 > 0 {
// ack the stall
setEPINTFLAG(0, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_STALL1)
// clear stall request
setEPINTENCLR(0, sam.USB_DEVICE_ENDPOINT_EPINTENCLR_STALL1)
}
}
// Now the actual transfer handlers, ignore endpoint number 0 (setup)
var i uint32
for i = 1; i < uint32(len(endPoints)); i++ {
// Check if endpoint has a pending interrupt
epFlags := getEPINTFLAG(i)
if (epFlags&sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT0) > 0 ||
(epFlags&sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1) > 0 {
switch i {
case usb_CDC_ENDPOINT_OUT:
handleEndpoint(i)
setEPINTFLAG(i, epFlags)
case usb_CDC_ENDPOINT_IN, usb_CDC_ENDPOINT_ACM:
setEPSTATUSCLR(i, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK1RDY)
setEPINTFLAG(i, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1)
if i == usb_CDC_ENDPOINT_IN {
UART0.waitTxc = false
}
}
}
}
}
func initEndpoint(ep, config uint32) {
switch config {
case usb_ENDPOINT_TYPE_INTERRUPT | usbEndpointIn:
// set packet size
usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.SetBits(epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos)
// set data buffer address
usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[ep]))))
// set endpoint type
setEPCFG(ep, ((usb_ENDPOINT_TYPE_INTERRUPT + 1) << sam.USB_DEVICE_ENDPOINT_EPCFG_EPTYPE1_Pos))
case usb_ENDPOINT_TYPE_BULK | usbEndpointOut:
// set packet size
usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.SetBits(epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos)
// set data buffer address
usbEndpointDescriptors[ep].DeviceDescBank[0].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_out_cache_buffer[ep]))))
// set endpoint type
setEPCFG(ep, ((usb_ENDPOINT_TYPE_BULK + 1) << sam.USB_DEVICE_ENDPOINT_EPCFG_EPTYPE0_Pos))
// receive interrupts when current transfer complete
setEPINTENSET(ep, sam.USB_DEVICE_ENDPOINT_EPINTENSET_TRCPT0)
// set byte count to zero, we have not received anything yet
usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
// ready for next transfer
setEPSTATUSCLR(ep, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK0RDY)
case usb_ENDPOINT_TYPE_INTERRUPT | usbEndpointOut:
// TODO: not really anything, seems like...
case usb_ENDPOINT_TYPE_BULK | usbEndpointIn:
// set packet size
usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.SetBits(epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos)
// set data buffer address
usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[ep]))))
// set endpoint type
setEPCFG(ep, ((usb_ENDPOINT_TYPE_BULK + 1) << sam.USB_DEVICE_ENDPOINT_EPCFG_EPTYPE1_Pos))
// NAK on endpoint IN, the bank is not yet filled in.
setEPSTATUSCLR(ep, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK1RDY)
case usb_ENDPOINT_TYPE_CONTROL:
// Control OUT
// set packet size
usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.SetBits(epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos)
// set data buffer address
usbEndpointDescriptors[ep].DeviceDescBank[0].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_out_cache_buffer[ep]))))
// set endpoint type
setEPCFG(ep, getEPCFG(ep)|((usb_ENDPOINT_TYPE_CONTROL+1)<<sam.USB_DEVICE_ENDPOINT_EPCFG_EPTYPE0_Pos))
// Control IN
// set packet size
usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.SetBits(epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos)
// set data buffer address
usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[ep]))))
// set endpoint type
setEPCFG(ep, getEPCFG(ep)|((usb_ENDPOINT_TYPE_CONTROL+1)<<sam.USB_DEVICE_ENDPOINT_EPCFG_EPTYPE1_Pos))
// Prepare OUT endpoint for receive
// set multi packet size for expected number of receive bytes on control OUT
usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.SetBits(64 << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)
// set byte count to zero, we have not received anything yet
usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
// NAK on endpoint OUT to show we are ready to receive control data
setEPSTATUSSET(ep, sam.USB_DEVICE_ENDPOINT_EPSTATUSSET_BK0RDY)
}
}
func handleStandardSetup(setup usbSetup) bool {
switch setup.bRequest {
case usb_GET_STATUS:
buf := []byte{0, 0}
if setup.bmRequestType != 0 { // endpoint
// TODO: actually check if the endpoint in question is currently halted
if isEndpointHalt {
buf[0] = 1
}
}
sendUSBPacket(0, buf)
return true
case usb_CLEAR_FEATURE:
if setup.wValueL == 1 { // DEVICEREMOTEWAKEUP
isRemoteWakeUpEnabled = false
} else if setup.wValueL == 0 { // ENDPOINTHALT
isEndpointHalt = false
}
sendZlp()
return true
case usb_SET_FEATURE:
if setup.wValueL == 1 { // DEVICEREMOTEWAKEUP
isRemoteWakeUpEnabled = true
} else if setup.wValueL == 0 { // ENDPOINTHALT
isEndpointHalt = true
}
sendZlp()
return true
case usb_SET_ADDRESS:
// set packet size 64 with auto Zlp after transfer
usbEndpointDescriptors[0].DeviceDescBank[1].PCKSIZE.Set((epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos) |
uint32(1<<31)) // autozlp
// ack the transfer is complete from the request
setEPINTFLAG(0, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1)
// set bank ready for data
setEPSTATUSSET(0, sam.USB_DEVICE_ENDPOINT_EPSTATUSSET_BK1RDY)
// wait for transfer to complete
timeout := 3000
for (getEPINTFLAG(0) & sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1) == 0 {
timeout--
if timeout == 0 {
return true
}
}
// last, set the device address to that requested by host
sam.USB_DEVICE.DADD.SetBits(setup.wValueL)
sam.USB_DEVICE.DADD.SetBits(sam.USB_DEVICE_DADD_ADDEN)
return true
case usb_GET_DESCRIPTOR:
sendDescriptor(setup)
return true
case usb_SET_DESCRIPTOR:
return false
case usb_GET_CONFIGURATION:
buff := []byte{usbConfiguration}
sendUSBPacket(0, buff)
return true
case usb_SET_CONFIGURATION:
if setup.bmRequestType&usb_REQUEST_RECIPIENT == usb_REQUEST_DEVICE {
for i := 1; i < len(endPoints); i++ {
initEndpoint(uint32(i), endPoints[i])
}
usbConfiguration = setup.wValueL
// Enable interrupt for CDC control messages from host (OUT packet)
setEPINTENSET(usb_CDC_ENDPOINT_ACM, sam.USB_DEVICE_ENDPOINT_EPINTENSET_TRCPT1)
// Enable interrupt for CDC data messages from host
setEPINTENSET(usb_CDC_ENDPOINT_OUT, sam.USB_DEVICE_ENDPOINT_EPINTENSET_TRCPT0)
sendZlp()
return true
} else {
return false
}
case usb_GET_INTERFACE:
buff := []byte{usbSetInterface}
sendUSBPacket(0, buff)
return true
case usb_SET_INTERFACE:
usbSetInterface = setup.wValueL
sendZlp()
return true
default:
return true
}
}
func cdcSetup(setup usbSetup) bool {
if setup.bmRequestType == usb_REQUEST_DEVICETOHOST_CLASS_INTERFACE {
if setup.bRequest == usb_CDC_GET_LINE_CODING {
var b [cdcLineInfoSize]byte
b[0] = byte(usbLineInfo.dwDTERate)
b[1] = byte(usbLineInfo.dwDTERate >> 8)
b[2] = byte(usbLineInfo.dwDTERate >> 16)
b[3] = byte(usbLineInfo.dwDTERate >> 24)
b[4] = byte(usbLineInfo.bCharFormat)
b[5] = byte(usbLineInfo.bParityType)
b[6] = byte(usbLineInfo.bDataBits)
sendUSBPacket(0, b[:])
return true
}
}
if setup.bmRequestType == usb_REQUEST_HOSTTODEVICE_CLASS_INTERFACE {
if setup.bRequest == usb_CDC_SET_LINE_CODING {
b, err := receiveUSBControlPacket()
if err != nil {
return false
}
usbLineInfo.dwDTERate = uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
usbLineInfo.bCharFormat = b[4]
usbLineInfo.bParityType = b[5]
usbLineInfo.bDataBits = b[6]
}
if setup.bRequest == usb_CDC_SET_CONTROL_LINE_STATE {
usbLineInfo.lineState = setup.wValueL
}
if setup.bRequest == usb_CDC_SET_LINE_CODING || setup.bRequest == usb_CDC_SET_CONTROL_LINE_STATE {
// auto-reset into the bootloader
if usbLineInfo.dwDTERate == 1200 && usbLineInfo.lineState&usb_CDC_LINESTATE_DTR == 0 {
ResetProcessor()
} else {
// TODO: cancel any reset
}
sendZlp()
}
if setup.bRequest == usb_CDC_SEND_BREAK {
// TODO: something with this value?
// breakValue = ((uint16_t)setup.wValueH << 8) | setup.wValueL;
// return false;
sendZlp()
}
return true
}
return false
}
//go:noinline
func sendUSBPacket(ep uint32, data []byte) {
copy(udd_ep_in_cache_buffer[ep][:], data)
// Set endpoint address for sending data
usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[ep]))))
// clear multi-packet size which is total bytes already sent
usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)
// set byte count, which is total number of bytes to be sent
usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.SetBits(uint32((len(data) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask) << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos))
}
func receiveUSBControlPacket() ([cdcLineInfoSize]byte, error) {
var b [cdcLineInfoSize]byte
// address
usbEndpointDescriptors[0].DeviceDescBank[0].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_out_cache_buffer[0]))))
// set byte count to zero
usbEndpointDescriptors[0].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
// set ready for next data
setEPSTATUSCLR(0, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK0RDY)
// Wait until OUT transfer is ready.
timeout := 300000
for (getEPSTATUS(0) & sam.USB_DEVICE_ENDPOINT_EPSTATUS_BK0RDY) == 0 {
timeout--
if timeout == 0 {
return b, errUSBCDCReadTimeout
}
}
// Wait until OUT transfer is completed.
timeout = 300000
for (getEPINTFLAG(0) & sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1) == 0 {
timeout--
if timeout == 0 {
return b, errUSBCDCReadTimeout
}
}
// get data
bytesread := uint32((usbEndpointDescriptors[0].DeviceDescBank[0].PCKSIZE.Get() >>
usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask)
if bytesread != cdcLineInfoSize {
return b, errUSBCDCBytesRead
}
copy(b[:7], udd_ep_out_cache_buffer[0][:7])
return b, nil
}
func handleEndpoint(ep uint32) {
// get data
count := int((usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.Get() >>
usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask)
// move to ring buffer
for i := 0; i < count; i++ {
UART0.Receive(byte((udd_ep_out_cache_buffer[ep][i] & 0xFF)))
}
// set byte count to zero
usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
// set multi packet size to 64
usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.SetBits(64 << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)
// set ready for next data
setEPSTATUSCLR(ep, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK0RDY)
}
func sendZlp() {
usbEndpointDescriptors[0].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
}
func epPacketSize(size uint16) uint32 {
switch size {
case 8:
return 0
case 16:
return 1
case 32:
return 2
case 64:
return 3
case 128:
return 4
case 256:
return 5
case 512:
return 6
case 1023:
return 7
default:
return 0
}
}
func getEPCFG(ep uint32) uint8 {
return sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPCFG.Get()
}
func setEPCFG(ep uint32, val uint8) {
sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPCFG.Set(val)
}
func setEPSTATUSCLR(ep uint32, val uint8) {
sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPSTATUSCLR.Set(val)
}
func setEPSTATUSSET(ep uint32, val uint8) {
sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPSTATUSSET.Set(val)
}
func getEPSTATUS(ep uint32) uint8 {
return sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPSTATUS.Get()
}
func getEPINTFLAG(ep uint32) uint8 {
return sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPINTFLAG.Get()
}
func setEPINTFLAG(ep uint32, val uint8) {
sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPINTFLAG.Set(val)
}
func setEPINTENCLR(ep uint32, val uint8) {
sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPINTENCLR.Set(val)
}
func setEPINTENSET(ep uint32, val uint8) {
sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPINTENSET.Set(val)
}
// ResetProcessor should perform a system reset in preparation
// to switch to the bootloader to flash new firmware.
func ResetProcessor() {
arm.DisableInterrupts()
// Perform magic reset into bootloader, as mentioned in
// https://github.com/arduino/ArduinoCore-samd/issues/197
*(*uint32)(unsafe.Pointer(uintptr(0x20000000 + HSRAM_SIZE - 4))) = RESET_MAGIC_VALUE
arm.SystemReset()
}
// DAC on the SAMD51.
type DAC struct {
}
var (
DAC0 = DAC{}
)
// DACConfig placeholder for future expansion.
type DACConfig struct {
}
// Configure the DAC.
// output pin must already be configured.
func (dac DAC) Configure(config DACConfig) {
// Turn on clock for DAC
sam.MCLK.APBDMASK.SetBits(sam.MCLK_APBDMASK_DAC_)
// Use Generic Clock Generator 4 as source for DAC.
sam.GCLK.PCHCTRL[42].Set((sam.GCLK_PCHCTRL_GEN_GCLK4 << sam.GCLK_PCHCTRL_GEN_Pos) | sam.GCLK_PCHCTRL_CHEN)
for sam.GCLK.SYNCBUSY.HasBits(sam.GCLK_SYNCBUSY_GENCTRL_GCLK4 << sam.GCLK_SYNCBUSY_GENCTRL_Pos) {
}
// reset DAC
sam.DAC.CTRLA.Set(sam.DAC_CTRLA_SWRST)
// wait for reset complete
for sam.DAC.CTRLA.HasBits(sam.DAC_CTRLA_SWRST) {
}
for sam.DAC.SYNCBUSY.HasBits(sam.DAC_SYNCBUSY_SWRST) {
}
// enable
sam.DAC.CTRLB.Set(sam.DAC_CTRLB_REFSEL_VREFPU << sam.DAC_CTRLB_REFSEL_Pos)
sam.DAC.DACCTRL[0].SetBits((sam.DAC_DACCTRL_CCTRL_CC12M << sam.DAC_DACCTRL_CCTRL_Pos) | sam.DAC_DACCTRL_ENABLE)
sam.DAC.CTRLA.Set(sam.DAC_CTRLA_ENABLE)
for sam.DAC.SYNCBUSY.HasBits(sam.DAC_SYNCBUSY_ENABLE) {
}
for !sam.DAC.STATUS.HasBits(sam.DAC_STATUS_READY0) {
}
}
// Set writes a single 16-bit value to the DAC.
// Since the ATSAMD51 only has a 12-bit DAC, the passed-in value will be scaled down.
func (dac DAC) Set(value uint16) error {
sam.DAC.DATA[0].Set(value >> 4)
syncDAC()
return nil
}
func syncDAC() {
for !sam.DAC.STATUS.HasBits(sam.DAC_STATUS_EOC0) {
}
for sam.DAC.SYNCBUSY.HasBits(sam.DAC_SYNCBUSY_DATA0) {
}
}