mirror of
https://github.com/tinygo-org/drivers.git
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soypat
103 lines
2.6 KiB
Go
103 lines
2.6 KiB
Go
package sd
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import (
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"errors"
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"time"
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"tinygo.org/x/drivers"
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)
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// See rustref.go for the new implementation.
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var (
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errBadCSDCID = errors.New("sd:bad CSD/CID in CRC or always1")
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errNoSDCard = errors.New("sd:no card")
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errCardNotSupported = errors.New("sd:card not supported")
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errWaitStartBlock = errors.New("sd:did not find start block token")
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errNeedBlockLenMultiple = errors.New("sd:need blocksize multiple for I/O")
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errWrite = errors.New("sd:write")
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errWriteTimeout = errors.New("sd:write timeout")
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errReadTimeout = errors.New("sd:read timeout")
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errBusyTimeout = errors.New("sd:busy card timeout")
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errOOB = errors.New("sd:oob block access")
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errNoblocks = errors.New("sd:no readable blocks")
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)
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type digitalPinout = func(b bool)
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type SPICard struct {
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bus drivers.SPI
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cs digitalPinout
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timers [2]timer
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numblocks int64
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timeout time.Duration
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wait time.Duration
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// Card Identification Register.
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cid CID
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// Card Specific Register.
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csd CSD
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bufcmd [6]byte
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kind CardKind
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// shift to calculate blocksize, taken from CSD.
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blockshift uint8
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lastCRC uint16
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}
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func NewSPICard(spi drivers.SPI, cs digitalPinout) *SPICard {
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const defaultTimeout = 300 * time.Millisecond
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s := &SPICard{
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bus: spi,
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cs: cs,
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}
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s.setTimeout(defaultTimeout)
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return s
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}
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// setTimeout sets the timeout for all operations and the wait time between each yield during busy spins.
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func (c *SPICard) setTimeout(timeout time.Duration) {
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if timeout <= 0 {
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panic("timeout must be positive")
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}
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c.timeout = timeout
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c.wait = timeout / 512
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}
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func (c *SPICard) csEnable(b bool) {
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c.cs(!b)
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}
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// LastReadCRC returns the CRC for the last ReadBlock operation.
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func (c *SPICard) LastReadCRC() uint16 { return c.lastCRC }
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// Init initializes the SD card. This routine should be performed with a SPI clock
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// speed of around 100..400kHz. One may increase the clock speed after initialization.
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func (d *SPICard) Init() error {
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return d.initRs()
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}
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func (d *SPICard) NumberOfBlocks() int64 {
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return d.numblocks
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}
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// CID returns a copy of the Card Identification Register value last read.
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func (d *SPICard) CID() CID { return d.cid }
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// CSD returns a copy of the Card Specific Data Register value last read.
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func (d *SPICard) CSD() CSD { return d.csd }
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func (d *SPICard) yield() { time.Sleep(d.wait) }
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type timer struct {
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deadline time.Time
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}
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func (t *timer) setTimeout(timeout time.Duration) *timer {
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t.deadline = time.Now().Add(timeout)
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return t
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}
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func (t timer) expired() bool {
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return time.Since(t.deadline) >= 0
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}
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