ARM: 9480/1: entry: expand comment in __switch_tografted

As per discussion between the developers in the mail thread
linked, expand the comment in __switch_to so that readers
of the code understand what is going on.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

1 files changed, 55 insertions, 0 deletions

diff --git a/Documentation/gpu/meson.rst b/Documentation/gpu/meson.rst
new file mode 100644
index 000000000..b9e2f9aa3
--- /dev/null
+++ b/Documentation/gpu/meson.rst
@@ -0,0 +1,55 @@
+=============================================
+drm/meson AmLogic Meson Video Processing Unit
+=============================================
+
+.. kernel-doc:: drivers/gpu/drm/meson/meson_drv.c
+   :doc: Video Processing Unit
+
+Video Processing Unit
+=====================
+
+The Amlogic Meson Display controller is composed of several components
+that are going to be documented below:
+
+.. code::
+
+  DMC|---------------VPU (Video Processing Unit)----------------|------HHI------|
+     | vd1   _______     _____________    _________________     |               |
+  D  |-------|      |----|            |   |                |    |   HDMI PLL    |
+  D  | vd2   | VIU  |    | Video Post |   | Video Encoders |<---|-----VCLK      |
+  R  |-------|      |----| Processing |   |                |    |               |
+     | osd2  |      |    |            |---| Enci ----------|----|-----VDAC------|
+  R  |-------| CSC  |----| Scalers    |   | Encp ----------|----|----HDMI-TX----|
+  A  | osd1  |      |    | Blenders   |   | Encl ----------|----|---------------|
+  M  |-------|______|----|____________|   |________________|    |               |
+  ___|__________________________________________________________|_______________|
+
+Video Input Unit
+================
+
+.. kernel-doc:: drivers/gpu/drm/meson/meson_viu.c
+   :doc: Video Input Unit
+
+Video Post Processing
+=====================
+
+.. kernel-doc:: drivers/gpu/drm/meson/meson_vpp.c
+   :doc: Video Post Processing
+
+Video Encoder
+=============
+
+.. kernel-doc:: drivers/gpu/drm/meson/meson_venc.c
+   :doc: Video Encoder
+
+Video Clocks
+============
+
+.. kernel-doc:: drivers/gpu/drm/meson/meson_vclk.c
+   :doc: Video Clocks
+
+HDMI Video Output
+=================
+
+.. kernel-doc:: drivers/gpu/drm/meson/meson_dw_hdmi.c
+   :doc: HDMI Output