[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 ae3cbc1..2353521 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;