drm: atmel-hlcdc: support extended timing ranges on sama5d4 and sama5d2

The display timings on old SoCs older than the sama5d4 are quite limited
and prevent the use of many displays. Add support for extended timing
ranges on sama5d2 and sama5d4.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: Nicolas Ferre <nicolas.ferre@atmel.com>

drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c

@@ -50,6 +50,9 @@ static const struct atmel_hlcdc_dc_desc atmel_hlcdc_dc_at91sam9n12 = {
 	.min_height = 0,
 	.max_width = 1280,
 	.max_height = 860,
+	.max_spw = 0x3f,
+	.max_vpw = 0x3f,
+	.max_hpw = 0xff,
 	.nlayers = ARRAY_SIZE(atmel_hlcdc_at91sam9n12_layers),
 	.layers = atmel_hlcdc_at91sam9n12_layers,
 };
@@ -134,6 +137,9 @@ static const struct atmel_hlcdc_dc_desc atmel_hlcdc_dc_at91sam9x5 = {
 	.min_height = 0,
 	.max_width = 800,
 	.max_height = 600,
+	.max_spw = 0x3f,
+	.max_vpw = 0x3f,
+	.max_hpw = 0xff,
 	.nlayers = ARRAY_SIZE(atmel_hlcdc_at91sam9x5_layers),
 	.layers = atmel_hlcdc_at91sam9x5_layers,
 };
@@ -237,6 +243,9 @@ static const struct atmel_hlcdc_dc_desc atmel_hlcdc_dc_sama5d3 = {
 	.min_height = 0,
 	.max_width = 2048,
 	.max_height = 2048,
+	.max_spw = 0x3f,
+	.max_vpw = 0x3f,
+	.max_hpw = 0x1ff,
 	.nlayers = ARRAY_SIZE(atmel_hlcdc_sama5d3_layers),
 	.layers = atmel_hlcdc_sama5d3_layers,
 };
@@ -320,6 +329,9 @@ static const struct atmel_hlcdc_dc_desc atmel_hlcdc_dc_sama5d4 = {
 	.min_height = 0,
 	.max_width = 2048,
 	.max_height = 2048,
+	.max_spw = 0xff,
+	.max_vpw = 0xff,
+	.max_hpw = 0x3ff,
 	.nlayers = ARRAY_SIZE(atmel_hlcdc_sama5d4_layers),
 	.layers = atmel_hlcdc_sama5d4_layers,
 };
@@ -358,19 +370,19 @@ int atmel_hlcdc_dc_mode_valid(struct atmel_hlcdc_dc *dc,
 	int hback_porch = mode->htotal - mode->hsync_end;
 	int hsync_len = mode->hsync_end - mode->hsync_start;
 
-	if (hsync_len > 0x40 || hsync_len < 1)
+	if (hsync_len > dc->desc->max_spw + 1 || hsync_len < 1)
 		return MODE_HSYNC;
 
-	if (vsync_len > 0x40 || vsync_len < 1)
+	if (vsync_len > dc->desc->max_spw + 1 || vsync_len < 1)
 		return MODE_VSYNC;
 
-	if (hfront_porch > 0x200 || hfront_porch < 1 ||
+	if (hfront_porch > dc->desc->max_hpw + 1 || hfront_porch < 1 ||
-	    hback_porch > 0x200 || hback_porch < 1 ||
+	    hback_porch > dc->desc->max_hpw + 1 || hback_porch < 1 ||
 	    mode->hdisplay < 1)
 		return MODE_H_ILLEGAL;
 
-	if (vfront_porch > 0x40 || vfront_porch < 1 ||
+	if (vfront_porch > dc->desc->max_vpw + 1 || vfront_porch < 1 ||
-	    vback_porch > 0x40 || vback_porch < 0 ||
+	    vback_porch > dc->desc->max_vpw || vback_porch < 0 ||
 	    mode->vdisplay < 1)
 		return MODE_V_ILLEGAL;
 

drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h

@@ -50,6 +50,9 @@
  * @min_height: minimum height supported by the Display Controller
  * @max_width: maximum width supported by the Display Controller
  * @max_height: maximum height supported by the Display Controller
+ * @max_spw: maximum vertical/horizontal pulse width
+ * @max_vpw: maximum vertical back/front porch width
+ * @max_hpw: maximum horizontal back/front porch width
  * @layers: a layer description table describing available layers
  * @nlayers: layer description table size
  */
@@ -58,6 +61,9 @@ struct atmel_hlcdc_dc_desc {
 	int min_height;
 	int max_width;
 	int max_height;
+	int max_spw;
+	int max_vpw;
+	int max_hpw;
 	const struct atmel_hlcdc_layer_desc *layers;
 	int nlayers;
 };