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-rw-r--r--include/video/display_timing.h124
1 files changed, 124 insertions, 0 deletions
diff --git a/include/video/display_timing.h b/include/video/display_timing.h
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+++ b/include/video/display_timing.h
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+/*
+ * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>
+ *
+ * description of display timings
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __LINUX_DISPLAY_TIMING_H
+#define __LINUX_DISPLAY_TIMING_H
+
+#include <linux/bitops.h>
+#include <linux/types.h>
+
+/* VESA display monitor timing parameters */
+#define VESA_DMT_HSYNC_LOW BIT(0)
+#define VESA_DMT_HSYNC_HIGH BIT(1)
+#define VESA_DMT_VSYNC_LOW BIT(2)
+#define VESA_DMT_VSYNC_HIGH BIT(3)
+
+/* display specific flags */
+#define DISPLAY_FLAGS_DE_LOW BIT(0) /* data enable flag */
+#define DISPLAY_FLAGS_DE_HIGH BIT(1)
+#define DISPLAY_FLAGS_PIXDATA_POSEDGE BIT(2) /* drive data on pos. edge */
+#define DISPLAY_FLAGS_PIXDATA_NEGEDGE BIT(3) /* drive data on neg. edge */
+#define DISPLAY_FLAGS_INTERLACED BIT(4)
+#define DISPLAY_FLAGS_DOUBLESCAN BIT(5)
+
+/*
+ * A single signal can be specified via a range of minimal and maximal values
+ * with a typical value, that lies somewhere inbetween.
+ */
+struct timing_entry {
+ u32 min;
+ u32 typ;
+ u32 max;
+};
+
+enum timing_entry_index {
+ TE_MIN = 0,
+ TE_TYP = 1,
+ TE_MAX = 2,
+};
+
+/*
+ * Single "mode" entry. This describes one set of signal timings a display can
+ * have in one setting. This struct can later be converted to struct videomode
+ * (see include/video/videomode.h). As each timing_entry can be defined as a
+ * range, one struct display_timing may become multiple struct videomodes.
+ *
+ * Example: hsync active high, vsync active low
+ *
+ * Active Video
+ * Video ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
+ * |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
+ * | | porch | | porch |
+ *
+ * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯
+ *
+ * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________
+ */
+struct display_timing {
+ struct timing_entry pixelclock;
+
+ struct timing_entry hactive; /* hor. active video */
+ struct timing_entry hfront_porch; /* hor. front porch */
+ struct timing_entry hback_porch; /* hor. back porch */
+ struct timing_entry hsync_len; /* hor. sync len */
+
+ struct timing_entry vactive; /* ver. active video */
+ struct timing_entry vfront_porch; /* ver. front porch */
+ struct timing_entry vback_porch; /* ver. back porch */
+ struct timing_entry vsync_len; /* ver. sync len */
+
+ unsigned int dmt_flags; /* VESA DMT flags */
+ unsigned int data_flags; /* video data flags */
+};
+
+/*
+ * This describes all timing settings a display provides.
+ * The native_mode is the default setting for this display.
+ * Drivers that can handle multiple videomodes should work with this struct and
+ * convert each entry to the desired end result.
+ */
+struct display_timings {
+ unsigned int num_timings;
+ unsigned int native_mode;
+
+ struct display_timing **timings;
+};
+
+/* get value specified by index from struct timing_entry */
+static inline u32 display_timing_get_value(const struct timing_entry *te,
+ enum timing_entry_index index)
+{
+ switch (index) {
+ case TE_MIN:
+ return te->min;
+ break;
+ case TE_TYP:
+ return te->typ;
+ break;
+ case TE_MAX:
+ return te->max;
+ break;
+ default:
+ return te->typ;
+ }
+}
+
+/* get one entry from struct display_timings */
+static inline struct display_timing *display_timings_get(const struct
+ display_timings *disp,
+ unsigned int index)
+{
+ if (disp->num_timings > index)
+ return disp->timings[index];
+ else
+ return NULL;
+}
+
+void display_timings_release(struct display_timings *disp);
+
+#endif