add status string method

examples/sd/main.go

@@ -62,7 +62,7 @@ func main() {
 	var buf [512]byte
 	for i := 0; i < 11; i += 1 {
 		time.Sleep(100 * time.Millisecond)
-		err = sdcard.ReadBlock(int64(i), buf[:])
+		err = sdcard.ReadBlock(0, buf[:])
 		if err != nil {
 			println("err reading block", i, ":", err.Error())
 			continue

sd/card.go

@@ -43,6 +43,8 @@ type SPICard struct {
 	timers    [2]timer
 	numblocks int64
 	timeout   time.Duration
+	// relative card address.
+	rca uint32
 }
 
 func NewSPICard(spi drivers.SPI, cs digitalPinout) *SPICard {
@@ -182,6 +184,12 @@ func (d *SPICard) Init() error {
 		return errNoblocks
 	}
 	d.numblocks = int64(nb)
+
+	err = d.readRegister(cmdSendRelativeAddr, d.buf[:4])
+	if err != nil {
+		return err
+	}
+	d.rca = binary.BigEndian.Uint32(d.buf[:4])
 	return nil
 }
 
@@ -271,6 +279,13 @@ func (d *SPICard) WriteBlock(block int64, src []byte) error {
 	return nil
 }
 
+func (d *SPICard) ReadStatus() (response1, error) {
+	if err := d.readRegister(cmdSendStatus, d.buf[:4]); err != nil {
+		return 0, err
+	}
+	return response1(binary.BigEndian.Uint32(d.buf[:4])), nil
+}
+
 // CID returns a copy of the Card Identification Register value last read.
 func (d *SPICard) CID() CID { return d.cid }
 

sd/definitions.go

@@ -476,6 +476,106 @@ const (
 	tokWRITE_MULT  = 0xfc
 )
 
+type status uint32
+
+// First status bits.
+//
+//go:generate stringer -type=status -trimprefix=status -output=status_string.go
+const (
+	statusRsvd0 status = iota
+	statusRsvd1
+	statusRsvd2
+	statusAuthSeqError
+	statusRsvdSDIO
+	statusAppCmd
+	statusFXEvent
+	statusRsvd7
+	statusReadyForData
+)
+
+// Upper bound status bits.
+const (
+	statusEraseReset status = iota + 13
+	statusECCDisabled
+	statusWPEraseSkip
+	statusCSDOverwrite
+	_
+	_
+	statusGenericError
+	statusControllerError // internal card controller error
+	statusECCFailed
+	statusIllegalCommand
+	statusComCRCError // CRC check of previous command failed
+	statusLockUnlockFailed
+	statusCardIsLocked    // Signals that the card is locked by the host.
+	statusWPViolation     // Write protected violation
+	statusEraseParamError // invalid write block selection for erase
+	statusEraseSeqError   // error in erase sequence
+	statusBlockLenError   // tx block length not allowed
+	statusAddrError       // misaligned address
+	statusAddrOutOfRange  // address out of range
+)
+
+// r1 is the normal response to a command.
+type r1 struct {
+	data [48 / 8]byte // 48 bits of response.
+}
+
+func (r *r1) RawCopy() [6]byte { return r.data }
+func (r *r1) startbit() bool {
+	return r.data[0]&(1<<7) != 0
+}
+func (r *r1) txbit() bool {
+	return r.data[0]&(1<<6) != 0
+}
+func (r *r1) cmdidx() uint8 {
+	return r.data[0] & 0b11_1111
+}
+func (r *r1) cardstatus() status {
+	return status(binary.BigEndian.Uint32(r.data[1:5]))
+}
+func (r *r1) CRC7() uint8  { return r.data[5] >> 1 }
+func (r *r1) endbit() bool { return r.data[5]&1 != 0 }
+
+func (r *r1) IsValid() bool {
+	return r.endbit() && CRC7(r.data[:5]) == r.CRC7()
+}
+
+type r6 struct {
+	data [48 / 8]byte
+}
+
+func (r *r6) RawCopy() [6]byte { return r.data }
+func (r *r6) startbit() bool {
+	return r.data[0]&(1<<7) != 0
+}
+func (r *r6) txbit() bool {
+	return r.data[0]&(1<<6) != 0
+}
+func (r *r6) cmdidx() uint8 {
+	return r.data[0] & 0b11_1111
+}
+func (r *r6) rca() uint16 {
+	return binary.BigEndian.Uint16(r.data[1:3])
+}
+func (r *r6) cardstatus() status {
+	moveBit := func(b status, from, to uint) status {
+		return (b & (1 << from)) >> from << to
+	}
+	// See 4.9.5 R6 (Published RCA response) of the SD Simplified Specification.
+	s := status(binary.BigEndian.Uint16(r.data[1:5]))
+	s = moveBit(s, 13, 19)
+	s = moveBit(s, 14, 22)
+	s = moveBit(s, 15, 23)
+	return s
+}
+func (r *r6) CRC7() uint8  { return r.data[5] >> 1 }
+func (r *r6) endbit() bool { return r.data[5]&1 != 0 }
+
+func (r *r6) IsValid() bool {
+	return r.endbit() && CRC7(r.data[:5]) == r.CRC7()
+}
+
 type response1 uint8
 
 func (r response1) IsIdle() bool          { return r&_R1_IDLE_STATE != 0 }

sd/status_string.go

@@ -0,0 +1,79 @@
+package sd
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[statusRsvd0-0]
+	_ = x[statusRsvd1-1]
+	_ = x[statusRsvd2-2]
+	_ = x[statusAuthSeqError-3]
+	_ = x[statusRsvdSDIO-4]
+	_ = x[statusAppCmd-5]
+	_ = x[statusFXEvent-6]
+	_ = x[statusRsvd7-7]
+	_ = x[statusReadyForData-8]
+	_ = x[statusEraseReset-13]
+	_ = x[statusECCDisabled-14]
+	_ = x[statusWPEraseSkip-15]
+	_ = x[statusCSDOverwrite-16]
+	_ = x[statusGenericError-19]
+	_ = x[statusControllerError-20]
+	_ = x[statusECCFailed-21]
+	_ = x[statusIllegalCommand-22]
+	_ = x[statusComCRCError-23]
+	_ = x[statusLockUnlockFailed-24]
+	_ = x[statusCardIsLocked-25]
+	_ = x[statusWPViolation-26]
+	_ = x[statusEraseParamError-27]
+	_ = x[statusEraseSeqError-28]
+	_ = x[statusBlockLenError-29]
+	_ = x[statusAddrError-30]
+	_ = x[statusAddrOutOfRange-31]
+}
+
+const (
+	_status_name_0 = "Rsvd0Rsvd1Rsvd2AuthSeqErrorRsvdSDIOAppCmdFXEventRsvd7ReadyForData"
+	_status_name_1 = "EraseResetECCDisabledWPEraseSkipCSDOverwrite"
+	_status_name_2 = "GenericErrorControllerErrorECCFailedIllegalCommandComCRCErrorLockUnlockFailedCardIsLockedWPViolationEraseParamErrorEraseSeqErrorBlockLenErrorAddrErrorAddrOutOfRange"
+)
+
+var (
+	_status_index_0 = [...]uint8{0, 5, 10, 15, 27, 35, 41, 48, 53, 65}
+	_status_index_1 = [...]uint8{0, 10, 21, 32, 44}
+	_status_index_2 = [...]uint8{0, 12, 27, 36, 50, 61, 77, 89, 100, 115, 128, 141, 150, 164}
+)
+
+func (i status) string() string {
+	switch {
+	case i <= 8:
+		return _status_name_0[_status_index_0[i]:_status_index_0[i+1]]
+	case 13 <= i && i <= 16:
+		i -= 13
+		return _status_name_1[_status_index_1[i]:_status_index_1[i+1]]
+	case 19 <= i && i <= 31:
+		i -= 19
+		return _status_name_2[_status_index_2[i]:_status_index_2[i+1]]
+	default:
+		return ""
+	}
+}
+
+func (s status) String() string {
+	return string(s.appendf(nil, ','))
+}
+
+func (s status) appendf(b []byte, delim byte) []byte {
+	b = append(b, '[')
+	if s == 0 {
+		return append(b, ']')
+	}
+	for bit := 0; bit < 32; bit++ {
+		if s&(1<<bit) != 0 {
+			b = append(b, status(bit).string()...)
+			b = append(b, delim)
+		}
+	}
+	b = append(b[:len(b)-1], ']')
+	return b
+}