added smbus_read_i2c_block_data

Author: mibo-fdc

Cargo.toml

@@ -2,7 +2,7 @@
 
 name = "i2cdev"
 build = "build.rs"
-version = "0.3.0"
+version = "0.3.1"
 authors = ["Paul Osborne <[email protected]>"]
 license = "MIT/Apache-2.0"
 repository = "https://github.com/rust-embedded/rust-i2cdev"

src/core.rs

@@ -90,6 +90,11 @@ pub trait I2CDevice {
     /// count bytes read from the device.
     fn smbus_read_block_data(&mut self, register: u8) -> Result<Vec<u8>, Self::Error>;
 
+    /// Read a block of up to 32 bytes from a device
+    ///
+    /// Uses read_i2c_block_data instead read_block_data.
+    fn smbus_read_i2c_block_data(&mut self, register: u8, len: u8) -> Result<Vec<u8>, Self::Error>;
+
     /// Write a block of up to 32 bytes to a device
     ///
     /// The opposite of the Block Read command, this writes up to 32 bytes to

src/ffi.rs

@@ -338,6 +338,23 @@ pub fn i2c_smbus_read_block_data(fd: RawFd, register: u8) -> Result<Vec<u8>, I2C
     Ok((&data.block[1..(count + 1) as usize]).to_vec())
 }
 
+pub fn i2c_smbus_read_i2c_block_data(fd: RawFd, register: u8, len: u8) -> Result<Vec<u8>, I2CError> {
+    let mut data = i2c_smbus_data::empty();
+    data.block[0] = len;
+    try!(unsafe {
+        i2c_smbus_access(fd,
+                         I2CSMBusReadWrite::I2C_SMBUS_READ,
+                         register,
+                         I2CSMBusSize::I2C_SMBUS_I2C_BLOCK_DATA,
+                         &mut data)
+    });
+
+    // create a vector from the data in the block starting at byte
+    // 1 and ending after count bytes after that
+    let count = data.block[0];
+    Ok((&data.block[1..(count + 1) as usize]).to_vec())
+}
+
 #[inline]
 pub fn i2c_smbus_write_block_data(fd: RawFd, register: u8, values: &[u8]) -> Result<(), I2CError> {
     let mut data = i2c_smbus_data::empty();

src/linux.rs

@@ -196,6 +196,11 @@ impl I2CDevice for LinuxI2CDevice {
         ffi::i2c_smbus_read_block_data(self.as_raw_fd(), register).map_err(From::from)
     }
 
+    /// Read a block of up to 32 bytes from a device via i2c_smbus_i2c_read_block_data
+    fn smbus_read_i2c_block_data(&mut self, register: u8, len: u8) -> Result<Vec<u8>, LinuxI2CError> {
+        ffi::i2c_smbus_read_i2c_block_data(self.as_raw_fd(), register, len).map_err(From::from)
+    }
+
     /// Write a block of up to 32 bytes to a device
     ///
     /// The opposite of the Block Read command, this writes up to 32 bytes to

src/mock.rs

@@ -91,4 +91,8 @@ impl I2CDevice for MockI2CDevice {
     fn smbus_process_block(&mut self, _register: u8, _values: &[u8]) -> I2CResult<()> {
         unimplemented!()
     }
+
+    fn smbus_read_i2c_block_data(&mut self, register: u8, len: u8) -> I2CResult<Vec<u8>> {
+        unimplemented!()
+    }
 }