[PATCHv2 2/2] v4l: vsp1: Provide a writeback video device

[Geert Uytterhoeven]

On Fri, Nov 4, 2016 at 6:53 PM, Kieran Bingham
 wrote:
> --- a/drivers/media/platform/vsp1/vsp1_video.c
> +++ b/drivers/media/platform/vsp1/vsp1_video.c

> +static void vsp1_video_wb_process_buffer(struct vsp1_video *video)
> +{

> +   if (buf) {
> +   video->rwpf->mem = buf->mem;
> +
> +   /*
> +* Store this buffer as pending. It will commence at the next
> +* frame start interrupt
> +*/
> +   video->pending = buf;
> +   list_del(>queue);
> +   } else {
> +   /* Disable writeback with no buffer */
> +   video->rwpf->mem = (struct vsp1_rwpf_memory) { 0 };

drivers/media/platform/vsp1/vsp1_video.c:946:30: warning: missing
braces around initializer [-Wmissing-braces]
   video->rwpf->mem = (struct vsp1_rwpf_memory) { 0 };

> +static void vsp1_video_wb_stop_streaming(struct vb2_queue *vq)
> +{
> +   struct vsp1_video *video = vb2_get_drv_priv(vq);
> +   struct vsp1_rwpf *rwpf = video->rwpf;
> +   struct vsp1_pipeline *pipe = rwpf->pipe;
> +   struct vsp1_vb2_buffer *buffer;
> +   unsigned long flags;
> +
> +   /*
> +* Disable the completion interrupts, and clear the WPF memory to
> +* prevent writing out frames
> +*/
> +   spin_lock_irqsave(>irqlock, flags);
> +   video->frame_end = NULL;
> +   rwpf->mem = (struct vsp1_rwpf_memory) { 0 };

drivers/media/platform/vsp1/vsp1_video.c:1008:22: warning: missing
braces around initializer [-Wmissing-braces]
  rwpf->mem = (struct vsp1_rwpf_memory) { 0 };

Either drop the "0":

mem = (struct vsp1_rwpf_memory) { };

or add an additional pair of braces:

mem = (struct vsp1_rwpf_memory) { { 0 } };

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 
linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

[PATCHv2 2/2] v4l: vsp1: Provide a writeback video device

[Kieran Bingham]

When the VSP1 is used in an active display pipeline, the output of the
WPF can supply the LIF entity directly and simultaneously write to
memory.

Support this functionality in the VSP1 driver, by extending the WPF
source pads, and establishing a V4L2 video device node connected to the
new source.

The source will be able to perform pixel format conversion, but not
rescaling, and as such the output from the memory node will always be
of the same dimensions as the display output.

Signed-off-by: Kieran Bingham 

---
Changes since RFC
 - Fix checkpatch.pl warnings
 - Adapt to use a single source pad for the Writeback and LIF
 - Use WPF properties to determine when to create links instead of VSP
 - Remove incorrect vsp1_video_verify_format() changes
 - Spelling and grammar fixes
---
 drivers/media/platform/vsp1/vsp1.h   |   1 +
 drivers/media/platform/vsp1/vsp1_drm.c   |  19 
 drivers/media/platform/vsp1/vsp1_drv.c   |   5 +-
 drivers/media/platform/vsp1/vsp1_rwpf.h  |   1 +
 drivers/media/platform/vsp1/vsp1_video.c | 150 ++-
 drivers/media/platform/vsp1/vsp1_video.h |   5 ++
 drivers/media/platform/vsp1/vsp1_wpf.c   |  19 +++-
 7 files changed, 193 insertions(+), 7 deletions(-)

diff --git a/drivers/media/platform/vsp1/vsp1.h 
b/drivers/media/platform/vsp1/vsp1.h
index 85387a64179a..a2d462264312 100644
--- a/drivers/media/platform/vsp1/vsp1.h
+++ b/drivers/media/platform/vsp1/vsp1.h
@@ -54,6 +54,7 @@ struct vsp1_uds;
 #define VSP1_HAS_WPF_HFLIP (1 << 6)
 #define VSP1_HAS_HGO   (1 << 7)
 #define VSP1_HAS_HGT   (1 << 8)
+#define VSP1_HAS_WPF_WRITEBACK (1 << 9)

 struct vsp1_device_info {
u32 version;
diff --git a/drivers/media/platform/vsp1/vsp1_drm.c 
b/drivers/media/platform/vsp1/vsp1_drm.c
index 0daf5f2c06e2..9bb7c1a04157 100644
--- a/drivers/media/platform/vsp1/vsp1_drm.c
+++ b/drivers/media/platform/vsp1/vsp1_drm.c
@@ -27,6 +27,7 @@
 #include "vsp1_lif.h"
 #include "vsp1_pipe.h"
 #include "vsp1_rwpf.h"
+#include "vsp1_video.h"


 /* 
-
@@ -479,6 +480,13 @@ void vsp1_du_atomic_flush(struct device *dev)
__func__, rpf->entity.index);
}

+   /*
+* If we have a writeback node attached, we use this opportunity to
+* update the video buffers.
+*/
+   if (pipe->output->video && pipe->output->video->frame_end)
+   pipe->output->video->frame_end(pipe);
+
/* Configure all entities in the pipeline. */
list_for_each_entry(entity, >entities, list_pipe) {
/* Disconnect unused RPFs from the pipeline. */
@@ -590,6 +598,16 @@ int vsp1_drm_create_links(struct vsp1_device *vsp1)
if (ret < 0)
return ret;

+   if (vsp1->wpf[0]->has_writeback) {
+   /* Connect the video device to the WPF for Writeback support */
+   ret = media_create_pad_link(>wpf[0]->entity.subdev.entity,
+   RWPF_PAD_SOURCE,
+   >wpf[0]->video->video.entity,
+   0, flags);
+   if (ret < 0)
+   return ret;
+   }
+
return 0;
 }

@@ -620,6 +638,7 @@ int vsp1_drm_init(struct vsp1_device *vsp1)
pipe->bru = >bru->entity;
pipe->lif = >lif->entity;
pipe->output = vsp1->wpf[0];
+   pipe->output->pipe = pipe;

return 0;
 }
diff --git a/drivers/media/platform/vsp1/vsp1_drv.c 
b/drivers/media/platform/vsp1/vsp1_drv.c
index 3b084976094b..42fa822b38d3 100644
--- a/drivers/media/platform/vsp1/vsp1_drv.c
+++ b/drivers/media/platform/vsp1/vsp1_drv.c
@@ -408,7 +408,7 @@ static int vsp1_create_entities(struct vsp1_device *vsp1)
vsp1->wpf[i] = wpf;
list_add_tail(>entity.list_dev, >entities);

-   if (vsp1->info->uapi) {
+   if (vsp1->info->uapi || wpf->has_writeback) {
struct vsp1_video *video = vsp1_video_create(vsp1, wpf);

if (IS_ERR(video)) {
@@ -705,7 +705,8 @@ static const struct vsp1_device_info vsp1_device_infos[] = {
.version = VI6_IP_VERSION_MODEL_VSPD_GEN3,
.model = "VSP2-D",
.gen = 3,
-   .features = VSP1_HAS_BRU | VSP1_HAS_LIF | VSP1_HAS_WPF_VFLIP,
+   .features = VSP1_HAS_BRU | VSP1_HAS_LIF | VSP1_HAS_WPF_VFLIP
+ | VSP1_HAS_WPF_WRITEBACK,
.rpf_count = 5,
.wpf_count = 2,
.num_bru_inputs = 5,
diff --git a/drivers/media/platform/vsp1/vsp1_rwpf.h 
b/drivers/media/platform/vsp1/vsp1_rwpf.h
index b4ffc38f48af..7502b467294a 100644
--- a/drivers/media/platform/vsp1/vsp1_rwpf.h
+++ b/drivers/media/platform/vsp1/vsp1_rwpf.h
@@ -53,6 +53,7 @@ struct vsp1_rwpf {

u32 mult_alpha;
u32 outfmt;
+