Re: [PATCH v2 3/7] drm_modes: add videomode_from_drm_display_mode

From: Emil Velikov <emil.l.velikov@gmail.com>
To: Philipp Zabel <p.zabel@pengutronix.de>,
	Steve Longerbeam <slongerbeam@gmail.com>
Cc: Fabio Estevam <fabio.estevam@freescale.com>,
	linux-fbdev@vger.kernel.org,
	Steve Longerbeam <steve_longerbeam@mentor.com>,
	emil.l.velikov@gmail.com, linux-kernel@vger.kernel.org,
	dri-devel@lists.freedesktop.org, Denis Carikli <denis@eukrea.com>,
	Tomi Valkeinen <tomi.valkeinen@ti.com>,
	Russell King <rmk+kernel@arm.linux.org.uk>,
	Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Subject: Re: [PATCH v2 3/7] drm_modes: add videomode_from_drm_display_mode
Date: Fri, 19 Dec 2014 19:03:49 +0000	[thread overview]
Message-ID: <54947695.3020108@gmail.com> (raw)
In-Reply-To: <1418986984.3165.64.camel@pengutronix.de>

On 19/12/14 11:03, Philipp Zabel wrote:
> Am Donnerstag, den 18.12.2014, 18:00 -0800 schrieb Steve Longerbeam:
>> Add conversion from drm_display_mode to videomode.
>>
>> Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
>> ---
>>  drivers/gpu/drm/drm_modes.c |   40 ++++++++++++++++++++++++++++++++++++++++
>>  include/drm/drm_modes.h     |    2 ++
>>  2 files changed, 42 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
>> index 6d8b941..583a391 100644
>> --- a/drivers/gpu/drm/drm_modes.c
>> +++ b/drivers/gpu/drm/drm_modes.c
>> @@ -615,6 +615,46 @@ void drm_display_mode_from_videomode(const struct videomode *vm,
>>  }
>>  EXPORT_SYMBOL_GPL(drm_display_mode_from_videomode);
>>  
>> +/**
>> + * videomode_from_drm_display_mode - fill in @vm using @dmode,
>> + * @dmode: drm_display_mode structure to use as source
>> + * @vm: videomode structure to use as destination
>> + *
>> + * Fills out @vm using the display mode specified in @dmode.
>> + */
>> +void videomode_from_drm_display_mode(const struct drm_display_mode *dmode,
>> +				     struct videomode *vm)
>> +{
>> +	vm->hactive = dmode->hdisplay;
>> +	vm->hfront_porch = dmode->hsync_start - dmode->hdisplay;
>> +	vm->hsync_len = dmode->hsync_end - dmode->hsync_start;
>> +	vm->hback_porch = dmode->htotal - dmode->hsync_end;
>> +
>> +	vm->vactive = dmode->vdisplay;
>> +	vm->vfront_porch = dmode->vsync_start - dmode->vdisplay;
>> +	vm->vsync_len = dmode->vsync_end - dmode->vsync_start;
>> +	vm->vback_porch = dmode->vtotal - dmode->vsync_end;
>> +
>> +	vm->pixelclock = dmode->clock * 1000;
>> +
>> +	vm->flags = 0;
>> +	if (dmode->flags & DRM_MODE_FLAG_PHSYNC)
>> +		vm->flags |= DISPLAY_FLAGS_HSYNC_HIGH;
>> +	else if (dmode->flags & DRM_MODE_FLAG_NHSYNC)
>> +		vm->flags |= DISPLAY_FLAGS_HSYNC_LOW;
>> +	if (dmode->flags & DRM_MODE_FLAG_PVSYNC)
>> +		vm->flags |= DISPLAY_FLAGS_VSYNC_HIGH;
>> +	else if (dmode->flags & DRM_MODE_FLAG_NVSYNC)
>> +		vm->flags |= DISPLAY_FLAGS_VSYNC_LOW;
>> +	if (dmode->flags & DRM_MODE_FLAG_INTERLACE)
>> +		vm->flags |= DISPLAY_FLAGS_INTERLACED;
>> +	if (dmode->flags & DRM_MODE_FLAG_DBLSCAN)
>> +		vm->flags |= DISPLAY_FLAGS_DOUBLESCAN;
>> +	if (dmode->flags & DRM_MODE_FLAG_DBLCLK)
>> +		vm->flags |= DISPLAY_FLAGS_DOUBLECLK;
>> +}
>> +EXPORT_SYMBOL_GPL(videomode_from_drm_display_mode);
> 
> Is it ok for drm_modes to export a function that doesn't start with
> drm_ ? We could just rename this to drm_display_mode_to_videomode if
> necessary. I can fix it up as I apply it, but I'd like to know which is
> preferred.
> 
Non-native English speaker here, and drm_display_mode_to_videomode
sounds better. Plus I think that *to* functions are more common than
*from* ones.

I'm not a drm dev, so just my 2c :)

Cheers,
Emil