Re: [PATCH v12 3/6] fbmon: add videomode helpers

Started by Laurent Pinchart on Nov 21, 2012 · 2 messages from 2 authors · Last reply Nov 22, 2012

open the first message on its own page

Message details and related content
Hi Steffen,

Sorry, I've just found another small bug below.

On Tuesday 20 November 2012 16:54:53 Steffen Trumtrar wrote:
quoted hunk
Add a function to convert from the generic videomode to a fb_videomode.

Signed-off-by: Steffen Trumtrar <redacted>
Reviewed-by: Thierry Reding <redacted>
Acked-by: Thierry Reding <redacted>
Tested-by: Thierry Reding <redacted>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/video/fbmon.c |   46 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/fb.h    |    6 ++++++
 2 files changed, 52 insertions(+)
diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c
index cef6557..c1939a6 100644
--- a/drivers/video/fbmon.c
+++ b/drivers/video/fbmon.c
@@ -31,6 +31,7 @@
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include <video/edid.h>
+#include <linux/videomode.h>
 #ifdef CONFIG_PPC_OF
 #include <asm/prom.h>
 #include <asm/pci-bridge.h>
@@ -1373,6 +1374,51 @@ int fb_get_mode(int flags, u32 val, struct
fb_var_screeninfo *var, struct fb_inf kfree(timings);
 	return err;
 }
+
+#if IS_ENABLED(CONFIG_VIDEOMODE)
+int fb_videomode_from_videomode(const struct videomode *vm,
+				struct fb_videomode *fbmode)
+{
+	unsigned int htotal, vtotal;
+
+	fbmode->xres = vm->hactive;
+	fbmode->left_margin = vm->hback_porch;
+	fbmode->right_margin = vm->hfront_porch;
+	fbmode->hsync_len = vm->hsync_len;

27 more quoted lines

This will fail if vm->pixelclock >= ((1 << 32) / 1000). The easiest solution 
is probably to use 64-bit computation.
quoted hunk
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fb_videomode_from_videomode);
+#endif
+
+
 #else
 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
 {
diff --git a/include/linux/fb.h b/include/linux/fb.h
index c7a9571..920cbe3 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -14,6 +14,7 @@
 #include <linux/backlight.h>
 #include <linux/slab.h>
 #include <asm/io.h>
+#include <linux/videomode.h>

 struct vm_area_struct;
 struct fb_info;
@@ -714,6 +715,11 @@ extern void fb_destroy_modedb(struct fb_videomode
*modedb); extern int fb_find_mode_cvt(struct fb_videomode *mode, int
margins, int rb); extern unsigned char *fb_ddc_read(struct i2c_adapter
*adapter);

+#if IS_ENABLED(CONFIG_VIDEOMODE)
+extern int fb_videomode_from_videomode(const struct videomode *vm,
+				       struct fb_videomode *fbmode);
+#endif
+
 /* drivers/video/modedb.c */
 #define VESA_MODEDB_SIZE 34
 extern void fb_var_to_videomode(struct fb_videomode *mode,
-- 
Regards,

Laurent Pinchart
Message details and related content
Hi Laurent,

On Wed, Nov 21, 2012 at 11:02:44PM +0100, Laurent Pinchart wrote:
Hi Steffen,
quoted
+
+	htotal = vm->hactive + vm->hfront_porch + vm->hback_porch +
+		 vm->hsync_len;
+	vtotal = vm->vactive + vm->vfront_porch + vm->vback_porch +
+		 vm->vsync_len;
+	fbmode->refresh = (vm->pixelclock * 1000) / (htotal * vtotal);
This will fail if vm->pixelclock >= ((1 << 32) / 1000). The easiest solution 
is probably to use 64-bit computation.
You have displays with a pixelclock > 4GHz?

Sascha

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