MDB adapter v2.0 over SPI

When VMC and keyboard (also I2C master) were talking to mega
simultaneously, mega (or keyboard) would go crazy, respond as random
slave addresses (as shown by i2cdetect) then stop responding at all.
Most likely it was caused by incorrect handling of TW_STATUS in my mega
firmware. Wasted two days of random changes without stable solution.

So we decided to rewrite everything to SPI, primarily because it's a
separate (even electrically) bus. Had we got ATMega328PB on hands or
similar device with more peripherals, I would choose UART for VMC-mega
communication.

Current implementation of SPI handler on mega is blocking other
interrupts for longer than required. This caused UART errors (likely buffer overflow).
Applied workaround to defer keyboard reports back to VMC while MDB
session in progress. It works reliably now with SPI speed 200-500KHz
and could be further improved by separating SPI IO from processing as
done in UART(MDB) part.

Among with other changes in mega protocol, basically it was downgraded
to single-tasking that Alex wanted from the start. I failed to make
ambitious async protocol work and it cost us precious time.

Author: temoto

cmd/display-mt16-test/main.go

@@ -37,7 +37,6 @@ func main() {
 
 	for {
 		d.WriteBytes(translate("Добро спасёт мир\n"))
-		time.Sleep(2000 * time.Millisecond)
 		d.WriteBytes(translate("если повезёт "))
 		d.Data(0x1c)
 		d.Data(0xbc)

cmd/mdb-cli/main.go

@@ -36,9 +36,8 @@ func main() {
 	cmdline := flag.NewFlagSet(os.Args[0], flag.ExitOnError)
 	devicePath := cmdline.String("device", "/dev/ttyAMA0", "")
 	iodinPath := cmdline.String("iodin", "./iodin", "Path to iodin executable")
-	megaI2CBus := cmdline.Uint("mega-i2c-bus", 0, "mega I2C bus number")
-	megaI2CAddr := cmdline.Uint("mega-i2c-addr", 0x78, "mega I2C address")
-	megaPin := cmdline.Int("mega-pin", 25, "mega notify pin")
+	megaSpi := cmdline.String("mega-spi", "", "mega SPI port")
+	megaPin := cmdline.String("mega-pin", "25", "mega notify pin")
 	uarterName := cmdline.String("io", "file", "file|iodin|mega")
 	cmdline.Parse(os.Args[1:])
 
@@ -55,7 +54,7 @@ func main() {
 		}
 		uarter = mdb.NewIodinUart(iodin)
 	case "mega":
-		mega, err := mega.NewClient(byte(*megaI2CBus), byte(*megaI2CAddr), *megaPin, log)
+		mega, err := mega.NewClient(*megaSpi, *megaPin, log)
 		if err != nil {
 			log.Fatal(errors.Trace(err))
 		}

cmd/mega-cli/main.go

@@ -27,14 +27,13 @@ var log = log2.NewStderr(log2.LDebug)
 
 func main() {
 	cmdline := flag.NewFlagSet(os.Args[0], flag.ExitOnError)
-	i2cBusNo := cmdline.Uint("i2cbus", 0, "")
-	addr := cmdline.Uint("addr", 0x78, "")
-	pin := cmdline.Int("pin", 25, "")
+	spiPort := cmdline.String("spi", "", "")
+	pin := cmdline.String("pin", "25", "")
 	cmdline.Parse(os.Args[1:])
 
 	log.SetFlags(log2.LInteractiveFlags)
 
-	client, err := mega.NewClient(byte(*i2cBusNo), byte(*addr), *pin, log)
+	client, err := mega.NewClient(*spiPort, *pin, log)
 	if err != nil {
 		log.Fatal(errors.ErrorStack(errors.Trace(err)))
 	}
@@ -115,23 +114,23 @@ func newExecutor(client *mega.Client) func(string) {
 					}
 					p, err := client.DoTimeout(mega.Command_t(bs[0]), bs[1:], mega.DefaultTimeout)
 					if err != nil {
-						log.Errorf("p rq=%x rs=%s err=%v", bs, p.String(), err)
+						log.Errorf("p rq=%x rs=%s err=%v", bs, p.ResponseString(), err)
 						return
 					}
-					log.Debugf("response=%x %s", p.Bytes(), p.String())
+					log.Infof("response=%s", p.ResponseString())
 				}
 			case word[0] == 'p':
 				if bs, err := hex.DecodeString(word[1:]); err != nil {
 					log.Errorf("token=%s err=%v", word, err)
 					return
 				} else {
-					p := mega.Packet{}
-					err := p.Parse(bs)
+					f := mega.Frame{}
+					err := f.Parse(bs)
 					if err != nil {
 						log.Errorf("parse input=%x err=%v", bs, err)
 						return
 					}
-					log.Info(p.String())
+					log.Info(f.ResponseString())
 				}
 			case word[0] == 'r':
 				if i, err := strconv.ParseUint(word[1:], 10, 32); err != nil {
@@ -140,15 +139,15 @@ func newExecutor(client *mega.Client) func(string) {
 					if i < 1 {
 						return
 					}
-					r := mega.PacketError{}
-					client.Tx(0, nil, true, 0, &r)
-					switch r.E {
+					r := mega.Frame{}
+					err = client.Tx(nil, &r, 0)
+					switch err {
 					case mega.ErrResponseEmpty:
 						log.Infof("read empty")
 					case nil:
-						log.Infof("packet=%s %s", r.P.SimpleHex(), r.P.String())
+						log.Infof("frame=%x %s", r.Bytes(), r.ResponseString())
 					default:
-						log.Errorf("read err=%v", r.E)
+						log.Errorf("read err=%v", err)
 						return
 					}
 				}
@@ -160,16 +159,20 @@ func newExecutor(client *mega.Client) func(string) {
 					time.Sleep(time.Duration(i) * time.Millisecond)
 				}
 			case word[0] == 't':
-				if bs, err := hex.DecodeString(word[1:]); err != nil {
-					log.Fatalf("token=%s err=%v", word, errors.ErrorStack(err))
+				bs, err := hex.DecodeString(word[1:])
+				if err != nil {
+					log.Errorf("token=%s err=%v", word, errors.ErrorStack(err))
+					return
+				}
+				f := new(mega.Frame)
+				if err = f.Parse(bs); err != nil {
+					log.Errorf("token=%x parse err=%v", bs, errors.ErrorStack(err))
+					return
+				}
+				err = client.Tx(f, nil, 0)
+				if err != nil {
+					log.Errorf("send err=%v", err)
 					return
-				} else {
-					r := mega.PacketError{}
-					client.Tx(0, bs, false, 0, &r)
-					if r.E != nil {
-						log.Errorf("send err=%v", r.E)
-						return
-					}
 				}
 			default:
 				log.Errorf("unknown command '%s'", word)

go.mod

@@ -2,20 +2,29 @@ module github.com/temoto/vender
 
 require (
 	github.com/awalterschulze/gographviz v0.0.0-20190221210632-1e9ccb565bca
-	github.com/brian-armstrong/gpio v0.0.0-20181227042754-72b0058bbbcb
 	github.com/c-bata/go-prompt v0.2.3
 	github.com/coreos/go-systemd v0.0.0-20190212144455-93d5ec2c7f76
 	github.com/golang/protobuf v1.2.0
 	github.com/hashicorp/hcl v1.0.0
 	github.com/juju/errors v0.0.0-20190207033735-e65537c515d7
+	github.com/juju/loggo v0.0.0-20190212223446-d976af380377 // indirect
+	github.com/juju/testing v0.0.0-20180920084828-472a3e8b2073 // indirect
+	github.com/kr/pretty v0.1.0 // indirect
+	github.com/mattn/go-colorable v0.1.1 // indirect
+	github.com/mattn/go-isatty v0.0.7 // indirect
 	github.com/mattn/go-runewidth v0.0.4 // indirect
+	github.com/mattn/go-tty v0.0.0-20181127064339-e4f871175a2f // indirect
 	github.com/nathan-osman/go-rpigpio v0.0.0-20160701025123-bce6190607da
 	github.com/paulrosania/go-charset v0.0.0-20151028000031-621bb39fcc83
 	github.com/pkg/errors v0.8.1
 	github.com/pkg/term v0.0.0-20190109203006-aa71e9d9e942 // indirect
 	github.com/temoto/alive v0.0.0-20180810133442-4a79f8881856
 	github.com/temoto/iodin v0.0.0-20190211111721-99c87617ba86
-	golang.org/x/net v0.0.0-20190213061140-3a22650c66bd
-	golang.org/x/sys v0.0.0-20190220154126-629670e5acc5
+	golang.org/x/net v0.0.0-20180826012351-8a410e7b638d
+	golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223
 	google.golang.org/grpc v1.18.0
+	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
+	gopkg.in/mgo.v2 v2.0.0-20180705113604-9856a29383ce // indirect
+	gopkg.in/yaml.v2 v2.2.2 // indirect
+	periph.io/x/periph v3.4.0+incompatible
 )

go.sum

@@ -1,16 +1,14 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
-github.com/awalterschulze/gographviz v0.0.0-20181013152038-b2885df04310 h1:t+qxRrRtwNiUYA+Xh2jSXhoG2grnMCMKX4Fg6lx9X1U=
-github.com/awalterschulze/gographviz v0.0.0-20181013152038-b2885df04310/go.mod h1:GEV5wmg4YquNw7v1kkyoX9etIk8yVmXj+AkDHuuETHs=
 github.com/awalterschulze/gographviz v0.0.0-20190221210632-1e9ccb565bca h1:xwIXr1FpA2XBoohlpvgb11No/zbsh5Clm/98PWPcHVA=
 github.com/awalterschulze/gographviz v0.0.0-20190221210632-1e9ccb565bca/go.mod h1:GEV5wmg4YquNw7v1kkyoX9etIk8yVmXj+AkDHuuETHs=
-github.com/brian-armstrong/gpio v0.0.0-20181227042754-72b0058bbbcb h1:VmtJv/dx6i7ze0RWn6iXfRyTEFdgK06+7elSCYec4Fg=
-github.com/brian-armstrong/gpio v0.0.0-20181227042754-72b0058bbbcb/go.mod h1:akEYRl6/10JSSoNEyjgoLKKrw1M8+uBh5xsQQzxXvHs=
 github.com/c-bata/go-prompt v0.2.3 h1:jjCS+QhG/sULBhAaBdjb2PlMRVaKXQgn+4yzaauvs2s=
 github.com/c-bata/go-prompt v0.2.3/go.mod h1:VzqtzE2ksDBcdln8G7mk2RX9QyGjH+OVqOCSiVIqS34=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/coreos/go-systemd v0.0.0-20190212144455-93d5ec2c7f76 h1:FE783w8WFh+Rvg+7bZ5g8p7gP4SeVS4AoNwkvazlsBg=
 github.com/coreos/go-systemd v0.0.0-20190212144455-93d5ec2c7f76/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b h1:VKtxabqXZkF25pY9ekfRL6a582T4P37/31XEstQ5p58=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
@@ -19,9 +17,26 @@ github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/juju/errors v0.0.0-20190207033735-e65537c515d7 h1:dMIPRDg6gi7CUp0Kj2+HxqJ5kTr1iAdzsXYIrLCNSmU=
 github.com/juju/errors v0.0.0-20190207033735-e65537c515d7/go.mod h1:W54LbzXuIE0boCoNJfwqpmkKJ1O4TCTZMetAt6jGk7Q=
+github.com/juju/loggo v0.0.0-20190212223446-d976af380377 h1:n6QjW3g5JNY3xPmIjFt6z1H6tFQA6BhwOC2bvTAm1YU=
+github.com/juju/loggo v0.0.0-20190212223446-d976af380377/go.mod h1:vgyd7OREkbtVEN/8IXZe5Ooef3LQePvuBm9UWj6ZL8U=
+github.com/juju/testing v0.0.0-20180920084828-472a3e8b2073 h1:WQM1NildKThwdP7qWrNAFGzp4ijNLw8RlgENkaI4MJs=
+github.com/juju/testing v0.0.0-20180920084828-472a3e8b2073/go.mod h1:63prj8cnj0tU0S9OHjGJn+b1h0ZghCndfnbQolrYTwA=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/mattn/go-colorable v0.1.1 h1:G1f5SKeVxmagw/IyvzvtZE4Gybcc4Tr1tf7I8z0XgOg=
+github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcnceauSikq3lYCQ=
+github.com/mattn/go-isatty v0.0.5 h1:tHXDdz1cpzGaovsTB+TVB8q90WEokoVmfMqoVcrLUgw=
+github.com/mattn/go-isatty v0.0.5/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
+github.com/mattn/go-isatty v0.0.7 h1:UvyT9uN+3r7yLEYSlJsbQGdsaB/a0DlgWP3pql6iwOc=
+github.com/mattn/go-isatty v0.0.7/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
 github.com/mattn/go-runewidth v0.0.4 h1:2BvfKmzob6Bmd4YsL0zygOqfdFnK7GR4QL06Do4/p7Y=
 github.com/mattn/go-runewidth v0.0.4/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
+github.com/mattn/go-tty v0.0.0-20181127064339-e4f871175a2f h1:4P7Ul+TAnk92vTeVkXs6VLjmf1EhrYtDRa03PCYY6VM=
+github.com/mattn/go-tty v0.0.0-20181127064339-e4f871175a2f/go.mod h1:XPvLUNfbS4fJH25nqRHfWLMa1ONC8Amw+mIA639KxkE=
 github.com/nathan-osman/go-rpigpio v0.0.0-20160701025123-bce6190607da h1:4fuSzRW9Os4EsqurEJtUADEZBAhYBQGDwMYEpm0tY70=
 github.com/nathan-osman/go-rpigpio v0.0.0-20160701025123-bce6190607da/go.mod h1:d9P2zqmuOhe7dbKtAOfSXL4vIB9BAjFj/+/vMULsVfE=
 github.com/paulrosania/go-charset v0.0.0-20151028000031-621bb39fcc83 h1:XQonH5Iv5rbyIkMJOQ4xKmKHQTh8viXtRSmep5Ca5I4=
@@ -35,14 +50,15 @@ github.com/temoto/alive v0.0.0-20180810133442-4a79f8881856/go.mod h1:byZzRaChaco
 github.com/temoto/iodin v0.0.0-20190211111721-99c87617ba86 h1:28eUgClE9ZSaq7N79vvygkYH0CoRSdx2eLBGaB/T4Uk=
 github.com/temoto/iodin v0.0.0-20190211111721-99c87617ba86/go.mod h1:PSCCOZs9yzxJX2JS1q+rk6pzNvFhs5HGfpnAmsELeMY=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
+golang.org/x/net v0.0.0-20180826012351-8a410e7b638d h1:g9qWBGx4puODJTMVyoPrpoxPFgVGd+z1DZwjfRu4d0I=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/net v0.0.0-20190213061140-3a22650c66bd h1:HuTn7WObtcDo9uEEU7rEqL0jYthdXAmZ6PP+meazmaU=
-golang.org/x/net v0.0.0-20190213061140-3a22650c66bd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
+golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f h1:wMNYb4v58l5UBM7MYRLPG6ZhfOqbKu7X5eyFl8ZhKvA=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20180830151530-49385e6e1522 h1:Ve1ORMCxvRmSXBwJK+t3Oy+V2vRW2OetUQBq4rJIkZE=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190220154126-629670e5acc5 h1:3Nsfe5Xa1wTt01QxlAFIY5j9ycDtS+d7mhvI8ZY5bn0=
-golang.org/x/sys v0.0.0-20190220154126-629670e5acc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223 h1:DH4skfRX4EBpamg7iV4ZlCpblAHI6s6TDM39bFZumv8=
+golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20180828015842-6cd1fcedba52/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
@@ -51,4 +67,13 @@ google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8 h1:Nw54tB0rB7hY/N0
 google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/grpc v1.18.0 h1:IZl7mfBGfbhYx2p2rKRtYgDFw6SBz+kclmxYrCksPPA=
 google.golang.org/grpc v1.18.0/go.mod h1:6QZJwpn2B+Zp71q/5VxRsJ6NXXVCE5NRUHRo+f3cWCs=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/mgo.v2 v2.0.0-20180705113604-9856a29383ce h1:xcEWjVhvbDy+nHP67nPDDpbYrY+ILlfndk4bRioVHaU=
+gopkg.in/mgo.v2 v2.0.0-20180705113604-9856a29383ce/go.mod h1:yeKp02qBN3iKW1OzL3MGk2IdtZzaj7SFntXj72NppTA=
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