Struct IoRequest

pub struct IoRequest<'a> { /* private fields */ }

An IO request for a specific device and resource.

Implementations

impl<'a> IoRequest<'a>

pub fn iomap_sized<const SIZE: usize>( self, ) -> impl PinInit<Devres<IoMem<SIZE>>, Error> + 'a

Maps an IoRequest where the size is known at compile time.

This uses the ioremap() C API.

Examples

The following example uses a kernel::platform::Device for illustration purposes.

use kernel::{bindings, c_str, platform, of, device::Core};
struct SampleDriver;

impl platform::Driver for SampleDriver {

   fn probe(
      pdev: &platform::Device<Core>,
      info: Option<&Self::IdInfo>,
   ) -> Result<Pin<KBox<Self>>> {
      let offset = 0; // Some offset.

      // If the size is known at compile time, use [`Self::iomap_sized`].
      //
      // No runtime checks will apply when reading and writing.
      let request = pdev.io_request_by_index(0).ok_or(ENODEV)?;
      let iomem = request.iomap_sized::<42>();
      let iomem = KBox::pin_init(iomem, GFP_KERNEL)?;

      let io = iomem.access(pdev.as_ref())?;

      // Read and write a 32-bit value at `offset`.
      let data = io.read32_relaxed(offset);

      io.write32_relaxed(data, offset);

    }
}

pub fn iomap_exclusive_sized<const SIZE: usize>( self, ) -> impl PinInit<Devres<ExclusiveIoMem<SIZE>>, Error> + 'a

Same as Self::iomap_sized but with exclusive access to the underlying region.

This uses the ioremap() C API.

pub fn iomap(self) -> impl PinInit<Devres<IoMem<0>>, Error> + 'a

Maps an IoRequest where the size is not known at compile time,

This uses the ioremap() C API.

Examples

The following example uses a kernel::platform::Device for illustration purposes.

use kernel::{bindings, c_str, platform, of, device::Core};
struct SampleDriver;

impl platform::Driver for SampleDriver {

   fn probe(
      pdev: &platform::Device<Core>,
      info: Option<&Self::IdInfo>,
   ) -> Result<Pin<KBox<Self>>> {
      let offset = 0; // Some offset.

      // Unlike [`Self::iomap_sized`], here the size of the memory region
      // is not known at compile time, so only the `try_read*` and `try_write*`
      // family of functions should be used, leading to runtime checks on every
      // access.
      let request = pdev.io_request_by_index(0).ok_or(ENODEV)?;
      let iomem = request.iomap();
      let iomem = KBox::pin_init(iomem, GFP_KERNEL)?;

      let io = iomem.access(pdev.as_ref())?;

      let data = io.try_read32_relaxed(offset)?;

      io.try_write32_relaxed(data, offset)?;

    }
}

pub fn iomap_exclusive( self, ) -> impl PinInit<Devres<ExclusiveIoMem<0>>, Error> + 'a

Same as Self::iomap but with exclusive access to the underlying region.