Add helper to get drm_display_mode from devicetree.
Signed-off-by: Steffen Trumtrar s.trumtrar@pengutronix.de Reviewed-by: Thierry Reding thierry.reding@avionic-design.de Acked-by: Thierry Reding thierry.reding@avionic-design.de Tested-by: Thierry Reding thierry.reding@avionic-design.de Tested-by: Philipp Zabel p.zabel@pengutronix.de --- drivers/gpu/drm/drm_modes.c | 35 ++++++++++++++++++++++++++++++++++- include/drm/drmP.h | 6 ++++++ 2 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c index 23d951a0..5508037 100644 --- a/drivers/gpu/drm/drm_modes.c +++ b/drivers/gpu/drm/drm_modes.c @@ -35,7 +35,8 @@ #include <linux/export.h> #include <drm/drmP.h> #include <drm/drm_crtc.h> -#include <linux/videomode.h> +#include <linux/of.h> +#include <linux/of_videomode.h>
/** * drm_mode_debug_printmodeline - debug print a mode @@ -541,6 +542,38 @@ int drm_display_mode_from_videomode(struct videomode *vm, EXPORT_SYMBOL_GPL(drm_display_mode_from_videomode); #endif
+#if IS_ENABLED(CONFIG_OF_VIDEOMODE) +/** + * of_get_drm_display_mode - get a drm_display_mode from devicetree + * @np: device_node with the timing specification + * @dmode: will be set to the return value + * @index: index into the list of display timings in devicetree + * + * This function is expensive and should only be used, if only one mode is to be + * read from DT. To get multiple modes start with of_get_display_timings and + * work with that instead. + */ +int of_get_drm_display_mode(struct device_node *np, + struct drm_display_mode *dmode, unsigned int index) +{ + struct videomode vm; + int ret; + + ret = of_get_videomode(np, &vm, index); + if (ret) + return ret; + + drm_display_mode_from_videomode(&vm, dmode); + + pr_info("%s: got %dx%d display mode from %s\n", __func__, vm.hactive, + vm.vactive, np->name); + drm_mode_debug_printmodeline(dmode); + + return 0; +} +EXPORT_SYMBOL_GPL(of_get_drm_display_mode); +#endif + /** * drm_mode_set_name - set the name on a mode * @mode: name will be set in this mode diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 341049c..ae132be 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -56,6 +56,7 @@ #include <linux/cdev.h> #include <linux/mutex.h> #include <linux/slab.h> +#include <linux/of.h> #include <linux/videomode.h> #if defined(__alpha__) || defined(__powerpc__) #include <asm/pgtable.h> /* For pte_wrprotect */ @@ -1459,6 +1460,11 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev, extern int drm_display_mode_from_videomode(struct videomode *vm, struct drm_display_mode *dmode); #endif +#if IS_ENABLED(CONFIG_OF_VIDEOMODE) +extern int of_get_drm_display_mode(struct device_node *np, + struct drm_display_mode *dmode, + unsigned int index); +#endif
/* Modesetting support */ extern void drm_vblank_pre_modeset(struct drm_device *dev, int crtc);