The virtio specification received a new mandatory feature
(VIRTIO_I2C_F_ZERO_LENGTH_REQUEST) for zero length requests. Fail if the
feature isn't offered by the device.
For each read-request, set the VIRTIO_I2C_FLAGS_M_RD flag, as required
by the VIRTIO_I2C_F_ZERO_LENGTH_REQUEST feature.
This allows us to support zero length requests, like SMBUS Quick, where
the buffer need not be sent anymore.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/7c58868cd26d2fc4bd82d0d8b0dfb55636380110.1634808714.git.viresh.kumar@linaro.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jie Deng <jie.deng@intel.com> # once the spec is merged
Add an I2C bus driver for virtio para-virtualization.
The controller can be emulated by the backend driver in
any device model software by following the virtio protocol.
The device specification can be found on
https://lists.oasis-open.org/archives/virtio-comment/202101/msg00008.html.
By following the specification, people may implement different
backend drivers to emulate different controllers according to
their needs.
Co-developed-by: Conghui Chen <conghui.chen@intel.com>
Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Signed-off-by: Jie Deng <jie.deng@intel.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Viresh Kumar