bcm27xx: import latest patches from the RPi foundation

bcm2708: boot tested on RPi B+ v1.2
bcm2709: boot tested on RPi 3B v1.2 and RPi 4B v1.1 4G
bcm2710: boot tested on RPi 3B v1.2
bcm2711: boot tested on RPi 4B v1.1 4G

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 217 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.4/950-0638-Documentation-media-Document-read-only-subdevice.patch b/target/linux/bcm27xx/patches-5.4/950-0638-Documentation-media-Document-read-only-subdevice.patch
new file mode 100644
index 0000000000..1983334ae1
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0638-Documentation-media-Document-read-only-subdevice.patch
@@ -0,0 +1,217 @@
+From c1a630e792140b4791bad84974e31b4a1cf09b1b Mon Sep 17 00:00:00 2001
+From: Jacopo Mondi <jacopo@jmondi.org>
+Date: Tue, 7 Apr 2020 17:21:56 +0200
+Subject: [PATCH] Documentation: media: Document read-only subdevice
+
+Document a new kAPI function to register subdev device nodes in read only
+mode and for each affected ioctl report how access is restricted.
+
+Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
+Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
+---
+ Documentation/media/kapi/v4l2-subdev.rst      | 44 +++++++++++++++++++
+ Documentation/media/uapi/v4l/dev-subdev.rst   |  5 +++
+ .../media/uapi/v4l/vidioc-g-dv-timings.rst    |  6 +++
+ Documentation/media/uapi/v4l/vidioc-g-std.rst |  6 +++
+ .../media/uapi/v4l/vidioc-subdev-g-crop.rst   |  9 ++++
+ .../media/uapi/v4l/vidioc-subdev-g-fmt.rst    |  8 ++++
+ .../v4l/vidioc-subdev-g-frame-interval.rst    |  8 ++++
+ .../uapi/v4l/vidioc-subdev-g-selection.rst    |  8 ++++
+ 8 files changed, 94 insertions(+)
+
+--- a/Documentation/media/kapi/v4l2-subdev.rst
++++ b/Documentation/media/kapi/v4l2-subdev.rst
+@@ -332,6 +332,50 @@ Private ioctls
+ 	All ioctls not in the above list are passed directly to the sub-device
+ 	driver through the core::ioctl operation.
+ 
++Read-only sub-device userspace API
++----------------------------------
++
++Bridge drivers that control their connected subdevices through direct calls to
++the kernel API realized by :c:type:`v4l2_subdev_ops` structure do not usually
++want userspace to be able to change the same parameters through the subdevice
++device node and thus do not usually register any.
++
++It is sometimes useful to report to userspace the current subdevice
++configuration through a read-only API, that does not permit applications to
++change to the device parameters but allows interfacing to the subdevice device
++node to inspect them.
++
++For instance, to implement cameras based on computational photography, userspace
++needs to know the detailed camera sensor configuration (in terms of skipping,
++binning, cropping and scaling) for each supported output resolution. To support
++such use cases, bridge drivers may expose the subdevice operations to userspace
++through a read-only API.
++
++To create a read-only device node for all the subdevices registered with the
++``V4L2_SUBDEV_FL_HAS_DEVNODE`` set, the :c:type:`v4l2_device` driver should call
++:c:func:`v4l2_device_register_ro_subdev_nodes`.
++
++Access to the following ioctls for userspace applications is restricted on
++sub-device device nodes registered with
++:c:func:`v4l2_device_register_ro_subdev_nodes`.
++
++``VIDIOC_SUBDEV_S_FMT``,
++``VIDIOC_SUBDEV_S_CROP``,
++``VIDIOC_SUBDEV_S_SELECTION``:
++
++	These ioctls are only allowed on a read-only subdevice device node
++	for the :ref:`V4L2_SUBDEV_FORMAT_TRY <v4l2-subdev-format-whence>`
++	formats and selection rectangles.
++
++``VIDIOC_SUBDEV_S_FRAME_INTERVAL``,
++``VIDIOC_SUBDEV_S_DV_TIMINGS``,
++``VIDIOC_SUBDEV_S_STD``:
++
++	These ioctls are not allowed on a read-only subdevice node.
++
++In case the ioctl is not allowed, or the format to modify is set to
++``V4L2_SUBDEV_FORMAT_ACTIVE``, the core returns a negative error code and
++the errno variable is set to ``-EPERM``.
+ 
+ I2C sub-device drivers
+ ----------------------
+--- a/Documentation/media/uapi/v4l/dev-subdev.rst
++++ b/Documentation/media/uapi/v4l/dev-subdev.rst
+@@ -39,6 +39,11 @@ will feature a character device node on
+ Sub-device character device nodes, conventionally named
+ ``/dev/v4l-subdev*``, use major number 81.
+ 
++Drivers may opt to limit the sub-device character devices to only expose
++operations that do not modify the device state. In such a case the sub-devices
++are referred to as ``read-only`` in the rest of this documentation, and the
++related restrictions are documented in individual ioctls.
++
+ 
+ Controls
+ ========
+--- a/Documentation/media/uapi/v4l/vidioc-g-dv-timings.rst
++++ b/Documentation/media/uapi/v4l/vidioc-g-dv-timings.rst
+@@ -57,6 +57,10 @@ pointer to the struct :c:type:`v4l2_dv_t
+ structure as argument. If the ioctl is not supported or the timing
+ values are not correct, the driver returns ``EINVAL`` error code.
+ 
++Calling ``VIDIOC_SUBDEV_S_DV_TIMINGS`` on a subdev device node that has been
++registered in read-only mode is not allowed. An error is returned and the errno
++variable is set to ``-EPERM``.
++
+ The ``linux/v4l2-dv-timings.h`` header can be used to get the timings of
+ the formats in the :ref:`cea861` and :ref:`vesadmt` standards. If
+ the current input or output does not support DV timings (e.g. if
+@@ -81,6 +85,8 @@ ENODATA
+ EBUSY
+     The device is busy and therefore can not change the timings.
+ 
++EPERM
++    ``VIDIOC_SUBDEV_S_DV_TIMINGS`` has been called on a read-only subdevice.
+ 
+ .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
+ 
+--- a/Documentation/media/uapi/v4l/vidioc-g-std.rst
++++ b/Documentation/media/uapi/v4l/vidioc-g-std.rst
+@@ -66,6 +66,9 @@ video timings (e.g. if :ref:`VIDIOC_ENUM
+ does not set the ``V4L2_IN_CAP_STD`` flag), then ``ENODATA`` error code is
+ returned.
+ 
++Calling ``VIDIOC_SUBDEV_S_STD`` on a subdev device node that has been registered
++in read-only mode is not allowed. An error is returned and the errno variable is
++set to ``-EPERM``.
+ 
+ Return Value
+ ============
+@@ -79,3 +82,6 @@ EINVAL
+ 
+ ENODATA
+     Standard video timings are not supported for this input or output.
++
++EPERM
++    ``VIDIOC_SUBDEV_S_STD`` has been called on a read-only subdevice.
+--- a/Documentation/media/uapi/v4l/vidioc-subdev-g-crop.rst
++++ b/Documentation/media/uapi/v4l/vidioc-subdev-g-crop.rst
+@@ -73,6 +73,11 @@ crop rectangles and stored in the sub-de
+ applications querying the same sub-device would thus not interact with
+ each other.
+ 
++If the subdev device node has been registered in read-only mode, calls to
++``VIDIOC_SUBDEV_S_CROP`` are only valid if the ``which`` field is set to
++``V4L2_SUBDEV_FORMAT_TRY``, otherwise an error is returned and the errno
++variable is set to ``-EPERM``.
++
+ Drivers must not return an error solely because the requested crop
+ rectangle doesn't match the device capabilities. They must instead
+ modify the rectangle to match what the hardware can provide. The
+@@ -123,3 +128,7 @@ EINVAL
+     references a non-existing pad, the ``which`` field references a
+     non-existing format, or cropping is not supported on the given
+     subdev pad.
++
++EPERM
++    The ``VIDIOC_SUBDEV_S_CROP`` ioctl has been called on a read-only subdevice
++    and the ``which`` field is set to ``V4L2_SUBDEV_FORMAT_ACTIVE``.
+--- a/Documentation/media/uapi/v4l/vidioc-subdev-g-fmt.rst
++++ b/Documentation/media/uapi/v4l/vidioc-subdev-g-fmt.rst
+@@ -78,6 +78,11 @@ current links configuration or sub-devic
+ a low-pass noise filter might crop pixels at the frame boundaries,
+ modifying its output frame size.
+ 
++If the subdev device node has been registered in read-only mode, calls to
++``VIDIOC_SUBDEV_S_FMT`` are only valid if the ``which`` field is set to
++``V4L2_SUBDEV_FORMAT_TRY``, otherwise an error is returned and the errno
++variable is set to ``-EPERM``.
++
+ Drivers must not return an error solely because the requested format
+ doesn't match the device capabilities. They must instead modify the
+ format to match what the hardware can provide. The modified format
+@@ -146,6 +151,9 @@ EINVAL
+     ``pad`` references a non-existing pad, or the ``which`` field
+     references a non-existing format.
+ 
++EPERM
++    The ``VIDIOC_SUBDEV_S_FMT`` ioctl has been called on a read-only subdevice
++    and the ``which`` field is set to ``V4L2_SUBDEV_FORMAT_ACTIVE``.
+ 
+ ============
+ 
+--- a/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst
++++ b/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst
+@@ -65,6 +65,10 @@ struct
+ contains the current frame interval as would be returned by a
+ ``VIDIOC_SUBDEV_G_FRAME_INTERVAL`` call.
+ 
++Calling ``VIDIOC_SUBDEV_S_FRAME_INTERVAL`` on a subdev device node that has been
++registered in read-only mode is not allowed. An error is returned and the errno
++variable is set to ``-EPERM``.
++
+ Drivers must not return an error solely because the requested interval
+ doesn't match the device capabilities. They must instead modify the
+ interval to match what the hardware can provide. The modified interval
+@@ -118,3 +122,7 @@ EINVAL
+     :c:type:`v4l2_subdev_frame_interval`
+     ``pad`` references a non-existing pad, or the pad doesn't support
+     frame intervals.
++
++EPERM
++    The ``VIDIOC_SUBDEV_S_FRAME_INTERVAL`` ioctl has been called on a read-only
++    subdevice.
+--- a/Documentation/media/uapi/v4l/vidioc-subdev-g-selection.rst
++++ b/Documentation/media/uapi/v4l/vidioc-subdev-g-selection.rst
+@@ -53,6 +53,10 @@ function of the crop API, and more, are
+ See :ref:`subdev` for more information on how each selection target
+ affects the image processing pipeline inside the subdevice.
+ 
++If the subdev device node has been registered in read-only mode, calls to
++``VIDIOC_SUBDEV_S_SELECTION`` are only valid if the ``which`` field is set to
++``V4L2_SUBDEV_FORMAT_TRY``, otherwise an error is returned and the errno
++variable is set to ``-EPERM``.
+ 
+ Types of selection targets
+ --------------------------
+@@ -123,3 +127,7 @@ EINVAL
+     ``pad`` references a non-existing pad, the ``which`` field
+     references a non-existing format, or the selection target is not
+     supported on the given subdev pad.
++
++EPERM
++    The ``VIDIOC_SUBDEV_S_SELECTION`` ioctl has been called on a read-only
++    subdevice and the ``which`` field is set to ``V4L2_SUBDEV_FORMAT_ACTIVE``.