[ARM] pxafb: add support for overlay1 and overlay2 as framebuffer devices

PXA27x and later processors support overlay1 and overlay2 on-top of the
base framebuffer (although under-neath the base is also possible). They
support palette and no-palette RGB formats, as well as YUV formats (only
available on overlay2). These overlays have dedicated DMA channels and
behave in a similar way as a framebuffer.

This heavily simplified and re-structured work is based on the original
pxafb_overlay.c (which is pending for mainline merge for a long time).

The major problems with this pxafb_overlay.c are (if you are interested
in the history):

  1. heavily redundant (the control logics for overlay1 and overlay2 are
     actually identical except for some small operations,  which are now
     abstracted into a 'pxafb_layer_ops' structure)

  2. a lot of useless and un-tested code (two workarounds which are now
     fixed on mature silicons)

  3. cursorfb is actually useless, hardware cursor should not be used
     this way, and the code was actually un-tested for a long time.

The code in this patch should be self-explanatory, I tried to add minimum
comments. As said, this is basically simplified, there are several things
still on the pending list:

  1. palette mode is un-supported and un-tested (although re-using the
     palette code of the base framebuffer is actually very easy now with
     previous clean-up patches)

  2. fb_pan_display for overlay(s) is un-supported

  3. the base framebuffer can actually be abstracted by 'pxafb_layer' as
     well, which will help further re-use of the code and keep a better
     and consistent structure. (This is the reason I named it 'pxafb_layer'
     instead of 'pxafb_overlay' or something alike)

See Documentation/fb/pxafb.txt for additional usage information.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Cc: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Eric Miao <ycmiao@ycmiao-hp520.(none)>

1 files changed, 45 insertions, 0 deletions

diff --git a/drivers/video/pxafb.h b/drivers/video/pxafb.h
index ae3cbc1ca64f..2353521c5c8c 100644
--- a/drivers/video/pxafb.h
+++ b/drivers/video/pxafb.h
@@ -64,6 +64,47 @@ struct pxafb_dma_buff {
         struct pxafb_dma_descriptor dma_desc[DMA_MAX * 2];
 };
 
+enum {
+        OVERLAY1,
+        OVERLAY2,
+};
+
+enum {
+        OVERLAY_FORMAT_RGB = 0,
+        OVERLAY_FORMAT_YUV444_PACKED,
+        OVERLAY_FORMAT_YUV444_PLANAR,
+        OVERLAY_FORMAT_YUV422_PLANAR,
+        OVERLAY_FORMAT_YUV420_PLANAR,
+};
+
+#define NONSTD_TO_XPOS(x)       (((x) >> 0)  & 0x3ff)
+#define NONSTD_TO_YPOS(x)       (((x) >> 10) & 0x3ff)
+#define NONSTD_TO_PFOR(x)       (((x) >> 20) & 0x7)
+
+struct pxafb_layer;
+
+struct pxafb_layer_ops {
+        void (*enable)(struct pxafb_layer *);
+        void (*disable)(struct pxafb_layer *);
+        void (*setup)(struct pxafb_layer *);
+};
+
+struct pxafb_layer {
+        struct fb_info          fb;
+        int                     id;
+        atomic_t                usage;
+        uint32_t                control[2];
+
+        struct pxafb_layer_ops  *ops;
+
+        void __iomem            *video_mem;
+        unsigned long           video_mem_phys;
+        size_t                  video_mem_size;
+        struct completion       branch_done;
+
+        struct pxafb_info       *fbi;
+};
+
 struct pxafb_info {
         struct fb_info          fb;
         struct device           *dev;
@@ -114,6 +155,10 @@ struct pxafb_info {
         struct task_struct      *smart_thread;
 #endif
 
+#ifdef CONFIG_FB_PXA_OVERLAY
+        struct pxafb_layer      overlay[2];
+#endif
+
 #ifdef CONFIG_CPU_FREQ
         struct notifier_block   freq_transition;
         struct notifier_block   freq_policy;