[RFC 1/3] drm/omap: Add ability to check if requested plane modes can be supported

[Benoit Parrot]

We currently assumed that an overlay has the same width and height as
the overlay manager. This assumption is incorrect. On some variant the
overlay manager is twice the width that the overlay can handle. We need
to add the appropriate data per variant as well as export a helper
function to retrieve the data so check can be made dynamically. We
currently add such a check in the dispc_ovl_setup() which will return an
error along with a WARN in case the required width exceed the overlay's
ability.

Signed-off-by: Benoit Parrot <bparrot at ti.com>
---
 drivers/gpu/drm/omapdrm/dss/dispc.c   | 29 +++++++++++++++++++++++++++++
 drivers/gpu/drm/omapdrm/dss/omapdss.h |  2 ++
 2 files changed, 31 insertions(+)

diff --git a/drivers/gpu/drm/omapdrm/dss/dispc.c b/drivers/gpu/drm/omapdrm/dss/dispc.c
index cfdcc3681494..1b7a6ef7897f 100644
--- a/drivers/gpu/drm/omapdrm/dss/dispc.c
+++ b/drivers/gpu/drm/omapdrm/dss/dispc.c
@@ -103,6 +103,8 @@ struct dispc_features {
 	u8 mgr_height_start;
 	u16 mgr_width_max;
 	u16 mgr_height_max;
+	u16 ovl_width_max;
+	u16 ovl_height_max;
 	unsigned long max_lcd_pclk;
 	unsigned long max_tv_pclk;
 	unsigned int max_downscale;
@@ -2605,6 +2607,13 @@ static int dispc_ovl_calc_scaling(struct dispc_device *dispc,
 	return 0;
 }
 
+static void dispc_ovl_get_max_size(struct dispc_device *dispc,
+				   u16 *width, u16 *height)
+{
+	*width = dispc->feat->ovl_width_max;
+	*height = dispc->feat->ovl_height_max;
+}
+
 static int dispc_ovl_setup_common(struct dispc_device *dispc,
 				  enum omap_plane_id plane,
 				  enum omap_overlay_caps caps,
@@ -2648,6 +2657,11 @@ static int dispc_ovl_setup_common(struct dispc_device *dispc,
 	out_width = out_width == 0 ? width : out_width;
 	out_height = out_height == 0 ? height : out_height;
 
+	if (WARN(out_width > dispc->feat->ovl_width_max,
+		 "Requested OVL width (%d) is larger than can be supported (%d).\n",
+		 out_width, dispc->feat->ovl_width_max))
+		return -EINVAL;
+
 	if (plane != OMAP_DSS_WB) {
 		if (ilace && height == out_height)
 			fieldmode = true;
@@ -4262,6 +4276,8 @@ static const struct dispc_features omap24xx_dispc_feats = {
 	.mgr_height_start	=	26,
 	.mgr_width_max		=	2048,
 	.mgr_height_max		=	2048,
+	.ovl_width_max		=	2048,
+	.ovl_height_max		=	2048,
 	.max_lcd_pclk		=	66500000,
 	.max_downscale		=	2,
 	/*
@@ -4299,6 +4315,8 @@ static const struct dispc_features omap34xx_rev1_0_dispc_feats = {
 	.mgr_height_start	=	26,
 	.mgr_width_max		=	2048,
 	.mgr_height_max		=	2048,
+	.ovl_width_max		=	2048,
+	.ovl_height_max		=	2048,
 	.max_lcd_pclk		=	173000000,
 	.max_tv_pclk		=	59000000,
 	.max_downscale		=	4,
@@ -4333,6 +4351,8 @@ static const struct dispc_features omap34xx_rev3_0_dispc_feats = {
 	.mgr_height_start	=	26,
 	.mgr_width_max		=	2048,
 	.mgr_height_max		=	2048,
+	.ovl_width_max		=	2048,
+	.ovl_height_max		=	2048,
 	.max_lcd_pclk		=	173000000,
 	.max_tv_pclk		=	59000000,
 	.max_downscale		=	4,
@@ -4367,6 +4387,8 @@ static const struct dispc_features omap36xx_dispc_feats = {
 	.mgr_height_start	=	26,
 	.mgr_width_max		=	2048,
 	.mgr_height_max		=	2048,
+	.ovl_width_max		=	2048,
+	.ovl_height_max		=	2048,
 	.max_lcd_pclk		=	173000000,
 	.max_tv_pclk		=	59000000,
 	.max_downscale		=	4,
@@ -4401,6 +4423,8 @@ static const struct dispc_features am43xx_dispc_feats = {
 	.mgr_height_start	=	26,
 	.mgr_width_max		=	2048,
 	.mgr_height_max		=	2048,
+	.ovl_width_max		=	2048,
+	.ovl_height_max		=	2048,
 	.max_lcd_pclk		=	173000000,
 	.max_tv_pclk		=	59000000,
 	.max_downscale		=	4,
@@ -4435,6 +4459,8 @@ static const struct dispc_features omap44xx_dispc_feats = {
 	.mgr_height_start	=	26,
 	.mgr_width_max		=	2048,
 	.mgr_height_max		=	2048,
+	.ovl_width_max		=	2048,
+	.ovl_height_max		=	2048,
 	.max_lcd_pclk		=	170000000,
 	.max_tv_pclk		=	185625000,
 	.max_downscale		=	4,
@@ -4474,6 +4500,8 @@ static const struct dispc_features omap54xx_dispc_feats = {
 	.mgr_height_start	=	27,
 	.mgr_width_max		=	4096,
 	.mgr_height_max		=	4096,
+	.ovl_width_max		=	2048,
+	.ovl_height_max		=	4096,
 	.max_lcd_pclk		=	170000000,
 	.max_tv_pclk		=	186000000,
 	.max_downscale		=	4,
@@ -4749,6 +4777,7 @@ static const struct dispc_ops dispc_ops = {
 	.ovl_enable = dispc_ovl_enable,
 	.ovl_setup = dispc_ovl_setup,
 	.ovl_get_color_modes = dispc_ovl_get_color_modes,
+	.ovl_get_max_size = dispc_ovl_get_max_size,
 
 	.wb_get_framedone_irq = dispc_wb_get_framedone_irq,
 	.wb_setup = dispc_wb_setup,
diff --git a/drivers/gpu/drm/omapdrm/dss/omapdss.h b/drivers/gpu/drm/omapdrm/dss/omapdss.h
index 14d74adb13fb..3f264759eecb 100644
--- a/drivers/gpu/drm/omapdrm/dss/omapdss.h
+++ b/drivers/gpu/drm/omapdrm/dss/omapdss.h
@@ -743,6 +743,8 @@ struct dispc_ops {
 
 	const u32 *(*ovl_get_color_modes)(struct dispc_device *dispc,
 					  enum omap_plane_id plane);
+	void (*ovl_get_max_size)(struct dispc_device *dispc,
+				 u16 *width, u16 *height);
 
 	u32 (*wb_get_framedone_irq)(struct dispc_device *dispc);
 	int (*wb_setup)(struct dispc_device *dispc,
-- 
2.9.0