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

- List: linux-fbdev
- 2 messages, 2 authors
- Page: https://ratatoskr.run/linux-fbdev/2012/11/8065942/t

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

- From: Laurent Pinchart \<hidden\>
- Date: 2012-11-21 22:02:44 
- Message: https://ratatoskr.run/linux-fbdev/2012/11/8065942.md

```text
Hi Steffen,

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

On Tuesday 20 November 2012 16:54:53 Steffen Trumtrar wrote:
> 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;
> +
> +	fbmode->yres = vm->vactive;
> +	fbmode->upper_margin = vm->vback_porch;
> +	fbmode->lower_margin = vm->vfront_porch;
> +	fbmode->vsync_len = vm->vsync_len;
> +
> +	fbmode->pixclock = KHZ2PICOS(vm->pixelclock / 1000);
> +
> +	fbmode->sync = 0;
> +	fbmode->vmode = 0;
> +	if (vm->hah)
> +		fbmode->sync |= FB_SYNC_HOR_HIGH_ACT;
> +	if (vm->vah)
> +		fbmode->sync |= FB_SYNC_VERT_HIGH_ACT;
> +	if (vm->interlaced)
> +		fbmode->vmode |= FB_VMODE_INTERLACED;
> +	if (vm->doublescan)
> +		fbmode->vmode |= FB_VMODE_DOUBLE;
> +	if (vm->de)
> +		fbmode->sync |= FB_SYNC_DATA_ENABLE_HIGH_ACT;
> +	fbmode->flag = 0;
> +
> +	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.

> +
> +	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

```

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

- From: Sascha Hauer \<hidden\>
- Date: 2012-11-22 06:20:00 
- Message: https://ratatoskr.run/linux-fbdev/2012/11/8065949.md

```text
Hi Laurent,

On Wed, Nov 21, 2012 at 11:02:44PM +0100, Laurent Pinchart wrote:
> Hi Steffen,
> 
> > +
> > +	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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```