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| author | Viresh Kumar <viresh.kumar@linaro.org> | 2021-10-21 15:17:49 +0530 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2021-11-01 05:26:48 -0400 |
| commit | dcce162559ee1ce5f64992c4c65197f9270e3d4f (patch) | |
| tree | a6130ea2ab1b5b628b4fd77d276b894a39cf295f /include/uapi/linux | |
| parent | f1aa12f53529ccd67722241792f39248bc89d353 (diff) | |
| download | linux-stable-dcce162559ee1ce5f64992c4c65197f9270e3d4f.tar.gz linux-stable-dcce162559ee1ce5f64992c4c65197f9270e3d4f.tar.bz2 linux-stable-dcce162559ee1ce5f64992c4c65197f9270e3d4f.zip | |
i2c: virtio: Add support for zero-length requests
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
Diffstat (limited to 'include/uapi/linux')
| -rw-r--r-- | include/uapi/linux/virtio_i2c.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/uapi/linux/virtio_i2c.h b/include/uapi/linux/virtio_i2c.h index 7c6a6fc01ad6..acf3b6069136 100644 --- a/include/uapi/linux/virtio_i2c.h +++ b/include/uapi/linux/virtio_i2c.h @@ -11,9 +11,15 @@ #include <linux/const.h> #include <linux/types.h> +/* Virtio I2C Feature bits */ +#define VIRTIO_I2C_F_ZERO_LENGTH_REQUEST 0 + /* The bit 0 of the @virtio_i2c_out_hdr.@flags, used to group the requests */ #define VIRTIO_I2C_FLAGS_FAIL_NEXT _BITUL(0) +/* The bit 1 of the @virtio_i2c_out_hdr.@flags, used to mark a buffer as read */ +#define VIRTIO_I2C_FLAGS_M_RD _BITUL(1) + /** * struct virtio_i2c_out_hdr - the virtio I2C message OUT header * @addr: the controlled device address |