[U-Boot] [PATCH 3/5] edid: Add an edid_dtd_to_fbmode() helper function

[Hans de Goede]

Various u-boot video drivers use fb_videomode structs to store timing info,
add a helper function to convert an EDID detailed timing into a fb_videomode
struct.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
 common/edid.c  | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/edid.h | 18 ++++++++++++++++
 2 files changed, 83 insertions(+)

diff --git a/common/edid.c b/common/edid.c
index e66108f..e41cd3e 100644
--- a/common/edid.c
+++ b/common/edid.c
@@ -12,6 +12,7 @@
 
 #include <common.h>
 #include <edid.h>
+#include <errno.h>
 #include <linux/ctype.h>
 #include <linux/string.h>
 
@@ -288,3 +289,67 @@ void edid_print_info(struct edid1_info *edid_info)
 	if (!have_timing)
 		printf("\tNone\n");
 }
+
+int edid_dtd_to_fbmode(struct edid_detailed_timing *t,
+		       struct fb_videomode *mode, char *name, int name_len)
+{
+	int margin, h_total, v_total;
+
+	if (EDID_DETAILED_TIMING_PIXEL_CLOCK(*t) == 0 ||
+	    EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(*t) == 0 ||
+	    EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(*t) == 0 ||
+	    EDID_DETAILED_TIMING_VERTICAL_ACTIVE(*t) == 0 ||
+	    EDID_DETAILED_TIMING_VERTICAL_BLANKING(*t) == 0 ||
+	    EDID_DETAILED_TIMING_HSYNC_OFFSET(*t) == 0 ||
+	    EDID_DETAILED_TIMING_HSYNC_PULSE_WIDTH(*t) == 0 ||
+	    EDID_DETAILED_TIMING_VSYNC_OFFSET(*t) == 0 ||
+	    EDID_DETAILED_TIMING_VSYNC_PULSE_WIDTH(*t) == 0)
+		return -EINVAL;
+
+	mode->name = name;
+	mode->xres = EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(*t);
+	mode->yres = EDID_DETAILED_TIMING_VERTICAL_ACTIVE(*t);
+	mode->pixclock = (EDID_DETAILED_TIMING_PIXEL_CLOCK(*t) + 500) /
+			 1000;
+
+	mode->left_margin = EDID_DETAILED_TIMING_HSYNC_OFFSET(*t);
+	mode->hsync_len = EDID_DETAILED_TIMING_HSYNC_PULSE_WIDTH(*t);
+	margin = EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(*t) -
+			(mode->left_margin + mode->hsync_len);
+	if (margin <= 0)
+		return -EINVAL;
+
+	mode->right_margin = margin;
+
+	mode->lower_margin = EDID_DETAILED_TIMING_VSYNC_OFFSET(*t);
+	mode->vsync_len = EDID_DETAILED_TIMING_VSYNC_PULSE_WIDTH(*t);
+	margin = EDID_DETAILED_TIMING_VERTICAL_BLANKING(*t) -
+			(mode->lower_margin + mode->vsync_len);
+	if (margin <= 0)
+		return -EINVAL;
+
+	mode->upper_margin = margin;
+
+	if (EDID_DETAILED_TIMING_FLAG_INTERLEAVED(*t))
+		mode->vmode = FB_VMODE_INTERLACED;
+	else
+		mode->vmode = FB_VMODE_NONINTERLACED;
+
+	mode->sync = 0;
+	if (EDID_DETAILED_TIMING_FLAG_HSYNC_POLARITY(*t))
+		mode->sync |= FB_SYNC_HOR_HIGH_ACT;
+	if (EDID_DETAILED_TIMING_FLAG_VSYNC_POLARITY(*t))
+		mode->sync |= FB_SYNC_VERT_HIGH_ACT;
+
+	mode->flag = 0;
+
+	h_total = mode->xres + EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(*t);
+	v_total = mode->yres + EDID_DETAILED_TIMING_VERTICAL_BLANKING(*t);
+	mode->refresh = EDID_DETAILED_TIMING_PIXEL_CLOCK(*t) /
+			(h_total * v_total);
+
+	snprintf(name, name_len, "%dx%d@%d", mode->xres, mode->yres,
+		 mode->refresh);
+
+	return 0;
+}
diff --git a/include/edid.h b/include/edid.h
index 480a773..d66f76b 100644
--- a/include/edid.h
+++ b/include/edid.h
@@ -13,6 +13,7 @@
 #ifndef __EDID_H_
 #define __EDID_H_
 
+#include <linux/fb.h>
 #include <linux/types.h>
 
 #define GET_BIT(_x, _pos) \
@@ -86,6 +87,10 @@ struct edid_detailed_timing {
 	GET_BITS((_x).flags, 4, 3)
 #define EDID_DETAILED_TIMING_FLAG_POLARITY(_x) \
 	GET_BITS((_x).flags, 2, 1)
+#define EDID_DETAILED_TIMING_FLAG_VSYNC_POLARITY(_x) \
+	GET_BIT((_x).flags, 2)
+#define EDID_DETAILED_TIMING_FLAG_HSYNC_POLARITY(_x) \
+	GET_BIT((_x).flags, 1)
 #define EDID_DETAILED_TIMING_FLAG_INTERLEAVED(_x) \
 	GET_BIT((_x).flags, 0)
 } __attribute__ ((__packed__));
@@ -255,4 +260,17 @@ int edid_get_ranges(struct edid1_info *edid, unsigned int *hmin,
 		    unsigned int *hmax, unsigned int *vmin,
 		    unsigned int *vmax);
 
+/**
+ * Convert an EDID detailed timing to a fb_videomode
+ *
+ * @param t		The EDID detailed timing to be converted
+ * @param mode		Returns the converted timing
+ * @param name		Buffer for the mode name mode->name will be set to this
+ * @param name_len	Length of name
+ *
+ * @return 0 on success, or a negative errno on error
+ */
+int edid_dtd_to_fbmode(struct edid_detailed_timing *t,
+		       struct fb_videomode *mode, char *name, int name_len);
+
 #endif /* __EDID_H_ */
-- 
2.1.0