Add helper to get drm_display_mode from devicetree.
Signed-off-by: Steffen Trumtrar <s.trumtrar at pengutronix.de>
---
drivers/gpu/drm/drm_modes.c | 42 ++++++++++++++++++++++++++++++++++++++++++
include/drm/drmP.h | 5 +++++
2 files changed, 47 insertions(+)
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 049624d..d51afe6 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -35,6 +35,7 @@
#include <linux/export.h>
#include <drm/drmP.h>
#include <drm/drm_crtc.h>
+#include <linux/of.h>
#include <linux/videomode.h>
/**
@@ -540,6 +541,47 @@ int videomode_to_display_mode(struct videomode *vm, struct
drm_display_mode *dmo
EXPORT_SYMBOL_GPL(videomode_to_display_mode);
#endif
+#if IS_ENABLED(CONFIG_OF_VIDEOMODE)
+static void dump_drm_displaymode(struct drm_display_mode *m)
+{
+ pr_debug("drm_displaymode = %d %d %d %d %d %d %d %d %d\n",
+ m->hdisplay, m->hsync_start, m->hsync_end, m->htotal,
+ m->vdisplay, m->vsync_start, m->vsync_end, m->vtotal,
+ m->clock);
+}
+
+/**
+ * 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
+ *
+ * DESCRIPTION:
+ * 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_timing_list
ond
+ * work with that instead.
+ */
+int of_get_drm_display_mode(struct device_node *np, struct drm_display_mode
*dmode,
+ int index)
+{
+ struct videomode vm;
+ int ret;
+
+ ret = of_get_videomode(np, &vm, index);
+ if (ret)
+ return ret;
+
+ videomode_to_display_mode(&vm, dmode);
+
+ pr_info("%s: got %dx%d display mode from %s\n", __func__, vm.hactive,
+ vm.vactive, np->name);
+ dump_drm_displaymode(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 e9fa1e3..4f9c44e 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 */
@@ -1457,6 +1458,10 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev,
extern int videomode_to_display_mode(struct videomode *vm,
struct drm_display_mode *dmode);
+extern int of_get_drm_display_mode(struct device_node *np,
+ struct drm_display_mode *dmode,
+ int index);
+
/* Modesetting support */
extern void drm_vblank_pre_modeset(struct drm_device *dev, int crtc);
extern void drm_vblank_post_modeset(struct drm_device *dev, int crtc);
--
1.7.10.4
