diff options
| -rw-r--r-- | .circleci/config.yml | 1 | ||||
| -rw-r--r-- | src/examples/i2s/i2s.go | 25 | ||||
| -rw-r--r-- | src/machine/board_circuitplay_express.go | 12 | ||||
| -rw-r--r-- | src/machine/board_itsybitsy-m0.go | 12 | ||||
| -rw-r--r-- | src/machine/i2s.go | 54 | ||||
| -rw-r--r-- | src/machine/machine_atsamd21.go | 229 |
6 files changed, 333 insertions, 0 deletions
diff --git a/.circleci/config.yml b/.circleci/config.yml index 9ca20a993..a1bfead64 100644 --- a/.circleci/config.yml +++ b/.circleci/config.yml @@ -82,6 +82,7 @@ commands: - run: tinygo build -size short -o test.elf -target=circuitplay-express examples/blinky1 - run: tinygo build -size short -o test.elf -target=stm32f4disco examples/blinky1 - run: tinygo build -size short -o test.elf -target=stm32f4disco examples/blinky2 + - run: tinygo build -size short -o test.elf -target=circuitplay-express examples/i2s - run: tinygo build -o wasm.wasm -target=wasm examples/wasm/export - run: tinygo build -o wasm.wasm -target=wasm examples/wasm/main test-linux: diff --git a/src/examples/i2s/i2s.go b/src/examples/i2s/i2s.go new file mode 100644 index 000000000..2f2c2f5b2 --- /dev/null +++ b/src/examples/i2s/i2s.go @@ -0,0 +1,25 @@ +// Example using the i2s hardware interface on the Adafruit Circuit Playground Express +// to read data from the onboard MEMS microphone. +// +package main + +import ( + "machine" +) + +func main() { + machine.I2S0.Configure(machine.I2SConfig{ + Mode: machine.I2SModePDM, + ClockSource: machine.I2SClockSourceExternal, + Stereo: true, + }) + + data := make([]uint32, 64) + + for { + // get the next group of samples + machine.I2S0.Read(data) + + println("data", data[0], data[1], data[2], data[4], "...") + } +} diff --git a/src/machine/board_circuitplay_express.go b/src/machine/board_circuitplay_express.go index 8da4276ab..311eeaae7 100644 --- a/src/machine/board_circuitplay_express.go +++ b/src/machine/board_circuitplay_express.go @@ -99,3 +99,15 @@ const ( var ( SPI0 = SPI{Bus: sam.SERCOM3_SPI} ) + +// I2S pins +const ( + I2S_SCK_PIN = PA10 + I2S_SD_PIN = PA08 + I2S_WS_PIN = 0xff // no WS, instead uses SCK to sync +) + +// I2S on the Circuit Playground Express. +var ( + I2S0 = I2S{Bus: sam.I2S} +) diff --git a/src/machine/board_itsybitsy-m0.go b/src/machine/board_itsybitsy-m0.go index 93966f282..f0ff15efc 100644 --- a/src/machine/board_itsybitsy-m0.go +++ b/src/machine/board_itsybitsy-m0.go @@ -73,3 +73,15 @@ const ( var ( SPI0 = SPI{Bus: sam.SERCOM4_SPI} ) + +// I2S pins +const ( + I2S_SCK_PIN = PA10 + I2S_SD_PIN = PA08 + I2S_WS_PIN = 0xff // TODO: figure out what this is on ItsyBitsy M0. +) + +// I2S on the ItsyBitsy M0. +var ( + I2S0 = I2S{Bus: sam.I2S} +) diff --git a/src/machine/i2s.go b/src/machine/i2s.go new file mode 100644 index 000000000..ed7589579 --- /dev/null +++ b/src/machine/i2s.go @@ -0,0 +1,54 @@ +// +build sam + +// This is the definition for I2S bus functions. +// Actual implementations if available for any given hardware +// are to be found in its the board definition. +// +// For more info about I2S, see: https://en.wikipedia.org/wiki/I%C2%B2S +// + +package machine + +type I2SMode uint8 +type I2SStandard uint8 +type I2SClockSource uint8 +type I2SDataFormat uint8 + +const ( + I2SModeMaster I2SMode = iota + I2SModeSlave + I2SModePDM +) + +const ( + I2StandardPhilips I2SStandard = iota + I2SStandardMSB + I2SStandardLSB +) + +const ( + I2SClockSourceInternal I2SClockSource = iota + I2SClockSourceExternal +) + +const ( + I2SDataFormatDefault I2SDataFormat = 0 + I2SDataFormat8bit = 8 + I2SDataFormat16bit = 16 + I2SDataFormat24bit = 24 + I2SDataFormat32bit = 32 +) + +// All fields are optional and may not be required or used on a particular platform. +type I2SConfig struct { + SCK uint8 + WS uint8 + SD uint8 + Mode I2SMode + Standard I2SStandard + ClockSource I2SClockSource + DataFormat I2SDataFormat + AudioFrequency uint32 + MasterClockOutput bool + Stereo bool +} diff --git a/src/machine/machine_atsamd21.go b/src/machine/machine_atsamd21.go index 278fa3c0b..89a62292c 100644 --- a/src/machine/machine_atsamd21.go +++ b/src/machine/machine_atsamd21.go @@ -808,6 +808,235 @@ func (i2c I2C) readByte() byte { return byte(i2c.Bus.DATA) } +// I2S on the SAMD21. + +// I2S +type I2S struct { + Bus *sam.I2S_Type +} + +// Configure is used to configure the I2S interface. You must call this +// before you can use the I2S bus. +func (i2s I2S) Configure(config I2SConfig) { + // handle defaults + if config.SCK == 0 { + config.SCK = I2S_SCK_PIN + config.WS = I2S_WS_PIN + config.SD = I2S_SD_PIN + } + + if config.AudioFrequency == 0 { + config.AudioFrequency = 48000 + } + + if config.DataFormat == I2SDataFormatDefault { + if config.Stereo { + config.DataFormat = I2SDataFormat16bit + } else { + config.DataFormat = I2SDataFormat32bit + } + } + + // Turn on clock for I2S + sam.PM.APBCMASK |= sam.PM_APBCMASK_I2S_ + + // setting clock rate for sample. + division_factor := CPU_FREQUENCY / (config.AudioFrequency * uint32(config.DataFormat)) + + // Switch Generic Clock Generator 3 to DFLL48M. + sam.GCLK.GENDIV = sam.RegValue((sam.GCLK_CLKCTRL_GEN_GCLK3 << sam.GCLK_GENDIV_ID_Pos) | + (division_factor << sam.GCLK_GENDIV_DIV_Pos)) + waitForSync() + + sam.GCLK.GENCTRL = sam.RegValue((sam.GCLK_CLKCTRL_GEN_GCLK3 << sam.GCLK_GENCTRL_ID_Pos) | + (sam.GCLK_GENCTRL_SRC_DFLL48M << sam.GCLK_GENCTRL_SRC_Pos) | + sam.GCLK_GENCTRL_IDC | + sam.GCLK_GENCTRL_GENEN) + waitForSync() + + // Use Generic Clock Generator 3 as source for I2S. + sam.GCLK.CLKCTRL = sam.RegValue16((sam.GCLK_CLKCTRL_ID_I2S_0 << sam.GCLK_CLKCTRL_ID_Pos) | + (sam.GCLK_CLKCTRL_GEN_GCLK3 << sam.GCLK_CLKCTRL_GEN_Pos) | + sam.GCLK_CLKCTRL_CLKEN) + waitForSync() + + // reset the device + i2s.Bus.CTRLA |= sam.I2S_CTRLA_SWRST + for (i2s.Bus.SYNCBUSY & sam.I2S_SYNCBUSY_SWRST) > 0 { + } + + // disable device before continuing + for (i2s.Bus.SYNCBUSY & sam.I2S_SYNCBUSY_ENABLE) > 0 { + } + i2s.Bus.CTRLA &^= sam.I2S_CTRLA_ENABLE + + // setup clock + if config.ClockSource == I2SClockSourceInternal { + // TODO: make sure correct for I2S output + + // set serial clock select pin + i2s.Bus.CLKCTRL0 |= sam.I2S_CLKCTRL_SCKSEL + + // set frame select pin + i2s.Bus.CLKCTRL0 |= sam.I2S_CLKCTRL_FSSEL + } else { + // Configure FS generation from SCK clock. + i2s.Bus.CLKCTRL0 &^= sam.I2S_CLKCTRL_FSSEL + } + + if config.Standard == I2StandardPhilips { + // set 1-bit delay + i2s.Bus.CLKCTRL0 |= sam.I2S_CLKCTRL_BITDELAY + } else { + // set 0-bit delay + i2s.Bus.CLKCTRL0 &^= sam.I2S_CLKCTRL_BITDELAY + } + + // set number of slots. + if config.Stereo { + i2s.Bus.CLKCTRL0 |= (1 << sam.I2S_CLKCTRL_NBSLOTS_Pos) + } else { + i2s.Bus.CLKCTRL0 &^= (1 << sam.I2S_CLKCTRL_NBSLOTS_Pos) + } + + // set slot size + switch config.DataFormat { + case I2SDataFormat8bit: + i2s.Bus.CLKCTRL0 |= sam.I2S_CLKCTRL_SLOTSIZE_8 + + case I2SDataFormat16bit: + i2s.Bus.CLKCTRL0 |= sam.I2S_CLKCTRL_SLOTSIZE_16 + + case I2SDataFormat24bit: + i2s.Bus.CLKCTRL0 |= sam.I2S_CLKCTRL_SLOTSIZE_24 + + case I2SDataFormat32bit: + i2s.Bus.CLKCTRL0 |= sam.I2S_CLKCTRL_SLOTSIZE_32 + } + + // configure pin for clock + GPIO{config.SCK}.Configure(GPIOConfig{Mode: GPIO_COM}) + + // configure pin for WS, if needed + if config.WS != 0xff { + GPIO{config.WS}.Configure(GPIOConfig{Mode: GPIO_COM}) + } + + // now set serializer data size. + switch config.DataFormat { + case I2SDataFormat8bit: + i2s.Bus.SERCTRL1 |= sam.I2S_SERCTRL_DATASIZE_8 + + case I2SDataFormat16bit: + i2s.Bus.SERCTRL1 |= sam.I2S_SERCTRL_DATASIZE_16 + + case I2SDataFormat24bit: + i2s.Bus.SERCTRL1 |= sam.I2S_SERCTRL_DATASIZE_24 + + case I2SDataFormat32bit: + case I2SDataFormatDefault: + i2s.Bus.SERCTRL1 |= sam.I2S_SERCTRL_DATASIZE_32 + } + + // set serializer slot adjustment + if config.Standard == I2SStandardLSB { + // adjust right + i2s.Bus.SERCTRL1 &^= sam.I2S_SERCTRL_SLOTADJ + } else { + // adjust left + i2s.Bus.SERCTRL1 |= sam.I2S_SERCTRL_SLOTADJ + + // reverse bit order? + i2s.Bus.SERCTRL1 |= sam.I2S_SERCTRL_BITREV + } + + // set serializer mode. + if config.Mode == I2SModePDM { + i2s.Bus.SERCTRL1 |= sam.I2S_SERCTRL_SERMODE_PDM2 + } else { + i2s.Bus.SERCTRL1 |= sam.I2S_SERCTRL_SERMODE_RX + } + + // configure data pin + GPIO{config.SD}.Configure(GPIOConfig{Mode: GPIO_COM}) + + // re-enable + i2s.Bus.CTRLA |= sam.I2S_CTRLA_ENABLE + for (i2s.Bus.SYNCBUSY & sam.I2S_SYNCBUSY_ENABLE) > 0 { + } + + // enable i2s clock + i2s.Bus.CTRLA |= sam.I2S_CTRLA_CKEN0 + for (i2s.Bus.SYNCBUSY & sam.I2S_SYNCBUSY_CKEN0) > 0 { + } + + // enable i2s serializer + i2s.Bus.CTRLA |= sam.I2S_CTRLA_SEREN1 + for (i2s.Bus.SYNCBUSY & sam.I2S_SYNCBUSY_SEREN1) > 0 { + } +} + +// Read data from the I2S bus into the provided slice. +// The I2S bus must already have been configured correctly. +func (i2s I2S) Read(p []uint32) (n int, err error) { + i := 0 + for i = 0; i < len(p); i++ { + // Wait until ready + for (i2s.Bus.INTFLAG & sam.I2S_INTFLAG_RXRDY1) == 0 { + } + + for (i2s.Bus.SYNCBUSY & sam.I2S_SYNCBUSY_DATA1) > 0 { + } + + // read data + p[i] = uint32(i2s.Bus.DATA1) + + // indicate read complete + i2s.Bus.INTFLAG = sam.I2S_INTFLAG_RXRDY1 + } + + return i, nil +} + +// Write data to the I2S bus from the provided slice. +// The I2S bus must already have been configured correctly. +func (i2s I2S) Write(p []uint32) (n int, err error) { + i := 0 + for i = 0; i < len(p); i++ { + // Wait until ready + for (i2s.Bus.INTFLAG & sam.I2S_INTFLAG_TXRDY1) == 0 { + } + + for (i2s.Bus.SYNCBUSY & sam.I2S_SYNCBUSY_DATA1) > 0 { + } + + // write data + i2s.Bus.DATA1 = sam.RegValue(p[i]) + + // indicate write complete + i2s.Bus.INTFLAG = sam.I2S_INTFLAG_TXRDY1 + } + + return i, nil +} + +// Close the I2S bus. +func (i2s I2S) Close() error { + // Sync wait + for (i2s.Bus.SYNCBUSY & sam.I2S_SYNCBUSY_ENABLE) > 0 { + } + + // disable I2S + i2s.Bus.CTRLA &^= sam.I2S_CTRLA_ENABLE + + return nil +} + +func waitForSync() { + for (sam.GCLK.STATUS & sam.GCLK_STATUS_SYNCBUSY) > 0 { + } +} + // SPI type SPI struct { Bus *sam.SERCOM_SPI_Type |