On Thu, Sep 13, 2012 at 03:40:40AM +0200, Laurent Pinchart wrote:
Hi Sascha,
+int panel_get_modes(struct panel *panel, const struct fb_videomode **modes) +{
- if (!panel->ops || !panel->ops->get_modes)
return 0;- return panel->ops->get_modes(panel, modes);
+} +EXPORT_SYMBOL_GPL(panel_get_modes);
You have seen my of videomode helper proposal. One result there was that we want to have ranges for the margin/synclen fields. Does it make sense to base this new panel framework on a more sophisticated internal reprentation of the panel parameters?
I think it does, yes. We need a common video mode structure, and the panel framework should use it. I'll try to rebase my patches on top of your proposal. Have you posted the latest version ?
V2 is the newest version. I'd like to implement ranges for the display timings which then makes for a new common video mode structure, which then could be used by drm and fbdev, probably with helper functions to convert from common videomode to drm/fbdev specific variants.
This could then be converted to struct fb_videomode / struct drm_display_mode as needed. This would also make it more suitable for drm drivers which are not interested in struct fb_videomode.
Related to this I suggest to change the API to be able to iterate over the different modes, like:
struct videomode *panel_get_mode(struct panel *panel, int num);
This was we do not have to have an array of modes in memory, which may be a burden for some panel drivers.
I currently have mixed feelings about this. Both approaches have pros and cons. Iterating over the modes would be more complex for drivers that use panels, and would be race-prone if the modes can change at runtime (OK, this isn't supported by the current panel API proposal).
I just remember that the array approach was painful when I worked on an fbdev driver some time ago. There some possible modes came from platform_data, other modes were default modes in the driver and all had to be merged into a single array. I don't remember the situation exactly, but it would have been simpler if it had been a list instead of an array.
Sascha