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Gpio cdev feature #29

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5e8ec37
Reformat project with rust fmt
almusil Dec 14, 2019
b50b73f
Add GPIO cdev feature
almusil Dec 14, 2019
ca1fa88
Gpio cdev add documentation
almusil Dec 15, 2019
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8 changes: 7 additions & 1 deletion Cargo.toml
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Original file line number Diff line number Diff line change
Expand Up @@ -8,14 +8,20 @@ name = "linux-embedded-hal"
repository = "https://github.com/japaric/linux-embedded-hal"
version = "0.3.0"

[features]
default = ["sysfs_gpio"]

gpio_cdev = ["gpio-cdev"]

[dependencies]
embedded-hal = { version = "0.2.3", features = ["unproven"] }
i2cdev = "0.4.3"
spidev = "0.4"
sysfs_gpio = "0.5"
serial-unix = "0.4.0"
serial-core = "0.4.0"
nb = "0.1.1"
sysfs_gpio = { version = "0.5", optional = true }
gpio-cdev = { version="0.2", optional = true }

[dev-dependencies]
openpty = "0.1.0"
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11 changes: 11 additions & 0 deletions README.md
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Expand Up @@ -8,6 +8,17 @@ This project is developed and maintained by the [Embedded Linux team][team].

## [Documentation](https://docs.rs/linux-embedded-hal)

## GPIO character device

Since Linux kernel v4.4 the use of sysfs GPIO was deprecated and replaced by the character device GPIO.
See [gpio-cdev documentation](https://github.com/rust-embedded/gpio-cdev#sysfs-gpio-vs-gpio-character-device) for details.

This crate includes feature flag `gpio_cdev` that replaces [sysfs_gpio](https://crates.io/crates/sysfs_gpio) by [gpio-cdev](https://crates.io/crates/gpio-cdev).
To enable it update your Cargo.toml.
```
linux-embedded-hal = { version = "0.3", features = ["gpio_cdev"] }
```

## License

Licensed under either of
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54 changes: 47 additions & 7 deletions src/lib.rs
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Expand Up @@ -11,15 +11,19 @@
//! [0]: https://crates.io/keywords/embedded-hal

#![deny(missing_docs)]
#![feature(doc_cfg)]
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is it possible to remove this? i don't think we want to stop building on stable

error[E0554]: `#![feature]` may not be used on the stable release channel
  --> src/lib.rs:14:1
   |
14 | #![feature(doc_cfg)]
   | ^^^^^^^^^^^^^^^^^^^^

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Sure, I am afraid that #[doc(cfg(feature = "gpio_cdev"))] won't work then. So I guess no point in keeping them either. WDYT?

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ahh yeah, that's a bit frustrating, i think building on stable is more important for now. i'd also like to see ci coverage (even though it's only running cargo check).

i guess we could build both in sub-paths (under default-features gates) and choose the default export with a feature, which would put them both in the docs, not require an additional test run, and let people runtime select if required, but, seems more complicated than is probably necessary.

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Ok I have created alternative PR #30 . Let me know which one we should proceed with. Thanks


extern crate cast;
extern crate embedded_hal as hal;
#[cfg(feature = "gpio_cdev")]
pub extern crate gpio_cdev;
pub extern crate i2cdev;
pub extern crate nb;
pub extern crate serial_core;
pub extern crate serial_unix;
pub extern crate spidev;
#[cfg(not(feature = "gpio_cdev"))]
pub extern crate sysfs_gpio;
pub extern crate serial_unix;
pub extern crate serial_core;
pub extern crate nb;

use std::io::{self, Write};
use std::path::{Path, PathBuf};
Expand Down Expand Up @@ -92,11 +96,32 @@ impl hal::blocking::delay::DelayMs<u64> for Delay {
}
}

/// Newtype around [`gpio_cdev::LineHandle`] that implements the `embedded-hal` traits
///
/// [`gpio_cdev::LineHandle`]: https://docs.rs/gpio-cdev/0.2.0/gpio_cdev/struct.LineHandle.html
#[cfg(feature = "gpio_cdev")]
#[doc(cfg(feature = "gpio_cdev"))]
pub struct Pin(pub gpio_cdev::LineHandle, bool);

#[cfg(feature = "gpio_cdev")]
#[doc(cfg(feature = "gpio_cdev"))]
impl Pin {
/// See [`gpio_cdev::Line::request`][0] for details.
///
/// [0]: https://docs.rs/gpio-cdev/0.2.0/gpio_cdev/struct.Line.html#method.request
pub fn new(handle: gpio_cdev::LineHandle) -> Result<Pin, gpio_cdev::errors::Error> {
let info = handle.line().info()?;
Ok(Pin(handle, info.is_active_low()))
}
}

/// Newtype around [`sysfs_gpio::Pin`] that implements the `embedded-hal` traits
///
/// [`sysfs_gpio::Pin`]: https://docs.rs/sysfs_gpio/0.5.1/sysfs_gpio/struct.Pin.html
#[cfg(not(feature = "gpio_cdev"))]
pub struct Pin(pub sysfs_gpio::Pin);

#[cfg(not(feature = "gpio_cdev"))]
impl Pin {
/// See [`sysfs_gpio::Pin::new`][0] for details.
///
Expand All @@ -117,6 +142,9 @@ impl Pin {
}

impl hal::digital::v2::OutputPin for Pin {
#[cfg(feature = "gpio_cdev")]
type Error = gpio_cdev::errors::Error;
#[cfg(not(feature = "gpio_cdev"))]
type Error = sysfs_gpio::Error;

fn set_low(&mut self) -> Result<(), Self::Error> {
Expand All @@ -129,8 +157,20 @@ impl hal::digital::v2::OutputPin for Pin {
}

impl hal::digital::v2::InputPin for Pin {
#[cfg(feature = "gpio_cdev")]
type Error = gpio_cdev::errors::Error;
#[cfg(not(feature = "gpio_cdev"))]
type Error = sysfs_gpio::Error;

#[cfg(feature = "gpio_cdev")]
fn is_high(&self) -> Result<bool, Self::Error> {
if !self.1 {
self.0.get_value().map(|val| val != 0)
} else {
self.0.get_value().map(|val| val == 0)
}
}
#[cfg(not(feature = "gpio_cdev"))]
fn is_high(&self) -> Result<bool, Self::Error> {
if !self.0.get_active_low()? {
self.0.get_value().map(|val| val != 0)
Expand All @@ -145,6 +185,9 @@ impl hal::digital::v2::InputPin for Pin {
}

impl ops::Deref for Pin {
#[cfg(feature = "gpio_cdev")]
type Target = gpio_cdev::LineHandle;
#[cfg(not(feature = "gpio_cdev"))]
type Target = sysfs_gpio::Pin;

fn deref(&self) -> &Self::Target {
Expand Down Expand Up @@ -220,10 +263,7 @@ impl hal::blocking::i2c::WriteRead for I2cdev {
buffer: &mut [u8],
) -> Result<(), Self::Error> {
self.set_address(address)?;
let mut messages = [
LinuxI2CMessage::write(bytes),
LinuxI2CMessage::read(buffer),
];
let mut messages = [LinuxI2CMessage::write(bytes), LinuxI2CMessage::read(buffer)];
self.inner.transfer(&mut messages).map(drop)
}
}
Expand Down