diff options
Diffstat (limited to '')
7 files changed, 348 insertions, 0 deletions
diff --git a/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/devfs.go b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/devfs.go new file mode 100644 index 0000000..3c7704f --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/devfs.go @@ -0,0 +1,80 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +//go:build linux +// +build linux + +package i2c + +import ( + "fmt" + "io" + "os" + "syscall" + + "golang.org/x/exp/io/i2c/driver" +) + +// Devfs is an I2C driver that works against the devfs. +// You need to load the "i2c-dev" kernel module to use this driver. +type Devfs struct { + // Dev is the I2C bus device, e.g. /dev/i2c-1. Required. + Dev string +} + +const ( + i2c_SLAVE = 0x0703 // TODO(jbd): Allow users to use I2C_SLAVE_FORCE? + i2c_TENBIT = 0x0704 +) + +// TODO(jbd): Support I2C_RETRIES and I2C_TIMEOUT at the driver and implementation level. + +func (d *Devfs) Open(addr int, tenbit bool) (driver.Conn, error) { + f, err := os.OpenFile(d.Dev, os.O_RDWR, os.ModeDevice) + if err != nil { + return nil, err + } + conn := &devfsConn{f: f} + if tenbit { + if err := conn.ioctl(i2c_TENBIT, uintptr(1)); err != nil { + conn.Close() + return nil, fmt.Errorf("cannot enable the 10-bit address mode on bus %v: %v", d.Dev, err) + } + } + if err := conn.ioctl(i2c_SLAVE, uintptr(addr)); err != nil { + conn.Close() + return nil, fmt.Errorf("error opening the address (%v) on the bus (%v): %v", addr, d.Dev, err) + } + return conn, nil +} + +type devfsConn struct { + f *os.File +} + +func (c *devfsConn) Tx(w, r []byte) error { + if w != nil { + if _, err := c.f.Write(w); err != nil { + return err + } + c.f.Sync() + } + if r != nil { + if _, err := io.ReadFull(c.f, r); err != nil { + return err + } + } + return nil +} + +func (c *devfsConn) Close() error { + return c.f.Close() +} + +func (c *devfsConn) ioctl(arg1, arg2 uintptr) error { + if _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, c.f.Fd(), arg1, arg2); errno != 0 { + return syscall.Errno(errno) + } + return nil +} diff --git a/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/devfs_nonlinux.go b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/devfs_nonlinux.go new file mode 100644 index 0000000..619fb9f --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/devfs_nonlinux.go @@ -0,0 +1,25 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +//go:build !linux +// +build !linux + +package i2c + +import ( + "errors" + + "golang.org/x/exp/io/i2c/driver" +) + +// Devfs is no-implementation so developers using cross compilation +// can rely on local tools even though the real implementation isn't +// available on their platform. +type Devfs struct { + Dev string +} + +func (d *Devfs) Open(addr int, tenbit bool) (driver.Conn, error) { + return nil, errors.New("not implemented on this platform") +} diff --git a/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/driver/driver.go b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/driver/driver.go new file mode 100644 index 0000000..3fe51a4 --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/driver/driver.go @@ -0,0 +1,24 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package driver contains interfaces to be implemented by various I2C implementations. +package driver // import "golang.org/x/exp/io/i2c/driver" + +// Opener opens a connection to an I2C device to communicate with +// the I2C address given. If the address is an 10-bit I2C address, +// tenbit is true. +type Opener interface { + Open(addr int, tenbit bool) (Conn, error) +} + +// Conn represents an active connection to an I2C device. +type Conn interface { + // Tx first writes w (if not nil), then reads len(r) + // bytes from device into r (if not nil) in a single + // I2C transaction. + Tx(w, r []byte) error + + // Close closes the connection. + Close() error +} diff --git a/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/example/displayip/main.go b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/example/displayip/main.go new file mode 100644 index 0000000..58fe694 --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/example/displayip/main.go @@ -0,0 +1,89 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package main contains a program that displays the IPv4 address +// of the machine on an a Grove-LCD RGB backlight. +package main + +import ( + "fmt" + "net" + + "golang.org/x/exp/io/i2c" +) + +const ( + DISPLAY_RGB_ADDR = 0x62 + DISPLAY_TEXT_ADDR = 0x3e +) + +func main() { + d, err := i2c.Open(&i2c.Devfs{Dev: "/dev/i2c-1"}, DISPLAY_RGB_ADDR) + if err != nil { + panic(err) + } + + td, err := i2c.Open(&i2c.Devfs{Dev: "/dev/i2c-1"}, DISPLAY_TEXT_ADDR) + if err != nil { + panic(err) + } + + // Set the backlight color to 100,100,100. + write(d, []byte{0, 0}) + write(d, []byte{1, 0}) + write(d, []byte{0x08, 0xaa}) + write(d, []byte{4, 100}) // R value + write(d, []byte{3, 100}) // G value + write(d, []byte{2, 100}) // B value + + ip, err := resolveIP() + if err != nil { + panic(err) + } + + fmt.Printf("host machine IP is %v\n", ip) + + write(td, []byte{0x80, 0x02}) // return home + write(td, []byte{0x80, 0x01}) // clean the display + write(td, []byte{0x80, 0x08 | 0x04}) // no cursor + write(td, []byte{0x80, 0x28}) // two lines + + for _, s := range ip { + write(td, []byte{0x40, byte(s)}) + } +} + +func write(d *i2c.Device, buf []byte) { + err := d.Write(buf) + if err != nil { + panic(err) + } +} + +func resolveIP() (string, error) { + var ip net.IP + ifaces, err := net.Interfaces() + if err != nil { + panic(err) + } + for _, i := range ifaces { + addrs, err := i.Addrs() + if err != nil { + panic(err) + } + for _, addr := range addrs { + switch v := addr.(type) { + case *net.IPNet: + ip = v.IP + case *net.IPAddr: + ip = v.IP + } + ip = ip.To4() + if ip != nil && ip.String() != "127.0.0.1" { + return ip.String(), nil + } + } + } + return "", fmt.Errorf("cannot resolve the IP") +} diff --git a/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/example_test.go b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/example_test.go new file mode 100644 index 0000000..aeedaeb --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/example_test.go @@ -0,0 +1,24 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package i2c_test + +import ( + "golang.org/x/exp/io/i2c" +) + +func ExampleOpen() { + d, err := i2c.Open(&i2c.Devfs{Dev: "/dev/i2c-1"}, 0x39) + if err != nil { + panic(err) + } + + // opens a 10-bit address + d, err = i2c.Open(&i2c.Devfs{Dev: "/dev/i2c-1"}, i2c.TenBit(0x78)) + if err != nil { + panic(err) + } + + _ = d +} diff --git a/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/i2c.go b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/i2c.go new file mode 100644 index 0000000..192ad3d --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/i2c.go @@ -0,0 +1,75 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package i2c allows users to read from and write to a slave I2C device. +// +// # Deprecated +// +// This package is not maintained anymore. An actively supported cross-platform +// alternative is https://periph.io/. +package i2c // import "golang.org/x/exp/io/i2c" + +import ( + "golang.org/x/exp/io/i2c/driver" +) + +const tenbitMask = 1 << 12 + +// Device represents an I2C device. Devices must be closed once +// they are no longer in use. +type Device struct { + conn driver.Conn +} + +// TenBit marks an I2C address as a 10-bit address. +func TenBit(addr int) int { + return addr | tenbitMask +} + +// Read reads len(buf) bytes from the device. +func (d *Device) Read(buf []byte) error { + return d.conn.Tx(nil, buf) +} + +// ReadReg is similar to Read but it reads from a register. +func (d *Device) ReadReg(reg byte, buf []byte) error { + return d.conn.Tx([]byte{reg}, buf) +} + +// Write writes the buffer to the device. If it is required to write to a +// specific register, the register should be passed as the first byte in the +// given buffer. +func (d *Device) Write(buf []byte) (err error) { + return d.conn.Tx(buf, nil) +} + +// WriteReg is similar to Write but writes to a register. +func (d *Device) WriteReg(reg byte, buf []byte) (err error) { + // TODO(jbd): Do not allocate, not optimal. + return d.conn.Tx(append([]byte{reg}, buf...), nil) +} + +// Close closes the device and releases the underlying sources. +func (d *Device) Close() error { + return d.conn.Close() +} + +// Open opens a connection to an I2C device. +// All devices must be closed once they are no longer in use. +// For devices that use 10-bit I2C addresses, addr can be marked +// as a 10-bit address with TenBit. +func Open(o driver.Opener, addr int) (*Device, error) { + unmasked, tenbit := resolveAddr(addr) + conn, err := o.Open(unmasked, tenbit) + if err != nil { + return nil, err + } + return &Device{conn: conn}, nil +} + +// resolveAddr returns whether the addr is 10-bit masked or not. +// It also returns the unmasked address. +func resolveAddr(addr int) (unmasked int, tenbit bool) { + return addr & (tenbitMask - 1), addr&tenbitMask == tenbitMask +} diff --git a/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/i2c_test.go b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/i2c_test.go new file mode 100644 index 0000000..8765e3e --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/exp@v0.0.0-20220613132600-b0d781184e0d/io/i2c/i2c_test.go @@ -0,0 +1,31 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package i2c + +import ( + "testing" +) + +func TestTenBit(t *testing.T) { + tc := []struct { + masked int + addrWant int + tenbitWant bool + }{ + {TenBit(0x5), 0x5, true}, + {0x5, 0x5, false}, + {TenBit(0x200), 0x200, true}, + } + + for _, tt := range tc { + unmasked, tenbit := resolveAddr(tt.masked) + if want, got := tt.tenbitWant, tenbit; got != want { + t.Errorf("want address %x as 10-bit; got non 10-bit", tt.masked) + } + if want, got := tt.addrWant, unmasked; got != want { + t.Errorf("want address %v; got %v", want, got) + } + } +} |