This patch adds a helper function for parsing videomodes from the devicetree.
The videomode can be either converted to a struct drm_display_mode or a
struct fb_videomode.
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
changes since v1:
- use hyphens instead of underscores for property names
.../devicetree/bindings/video/displaymode | 40 ++++++++
drivers/of/Kconfig | 5 +
drivers/of/Makefile | 1 +
drivers/of/of_videomode.c | 108 ++++++++++++++++++++
include/linux/of_videomode.h | 19 ++++
5 files changed, 173 insertions(+)
create mode 100644 Documentation/devicetree/bindings/video/displaymode
create mode 100644 drivers/of/of_videomode.c
create mode 100644 include/linux/of_videomode.h
diff --git a/Documentation/devicetree/bindings/video/displaymode
b/Documentation/devicetree/bindings/video/displaymode
new file mode 100644
index 0000000..43cc17d
--- /dev/null
+++ b/Documentation/devicetree/bindings/video/displaymode
@@ -0,0 +1,40 @@
+videomode bindings
+==================
+
+Required properties:
+ - xres, yres: Display resolution
+ - left-margin, right-margin, hsync-len: Horizontal Display timing parameters
+ in pixels
+ upper-margin, lower-margin, vsync-len: Vertical display timing parameters in
+ lines
+ - clock: displayclock in Hz
+
+Optional properties:
+ - width-mm, height-mm: Display dimensions in mm
+ - hsync-active-high (bool): Hsync pulse is active high
+ - vsync-active-high (bool): Vsync pulse is active high
+ - interlaced (bool): This is an interlaced mode
+ - doublescan (bool): This is a doublescan mode
+
+There are different ways of describing a display mode. The devicetree
representation
+corresponds to the one used by the Linux Framebuffer framework described here
in
+Documentation/fb/framebuffer.txt. This representation has been chosen because
it's
+the only format which does not allow for inconsistent parameters.Unlike the
Framebuffer
+framework the devicetree has the clock in Hz instead of ps.
+
+Example:
+
+ display at 0 {
+ /* 1920x1080p24 */
+ clock = <52000000>;
+ xres = <1920>;
+ yres = <1080>;
+ left-margin = <25>;
+ right-margin = <25>;
+ hsync-len = <25>;
+ lower-margin = <2>;
+ upper-margin = <2>;
+ vsync-len = <2>;
+ hsync-active-high;
+ };
+
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index dfba3e6..a3acaa3 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -83,4 +83,9 @@ config OF_MTD
depends on MTD
def_bool y
+config OF_VIDEOMODE
+ def_bool y
+ help
+ helper to parse videomodes from the devicetree
+
endmenu # OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index e027f44..80e6db3 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_OF_MDIO) += of_mdio.o
obj-$(CONFIG_OF_PCI) += of_pci.o
obj-$(CONFIG_OF_PCI_IRQ) += of_pci_irq.o
obj-$(CONFIG_OF_MTD) += of_mtd.o
+obj-$(CONFIG_OF_VIDEOMODE) += of_videomode.o
diff --git a/drivers/of/of_videomode.c b/drivers/of/of_videomode.c
new file mode 100644
index 0000000..50d3bd2
--- /dev/null
+++ b/drivers/of/of_videomode.c
@@ -0,0 +1,108 @@
+/*
+ * OF helpers for parsing display modes
+ *
+ * Copyright (c) 2012 Sascha Hauer <s.hauer at pengutronix.de>, Pengutronix
+ *
+ * This file is released under the GPLv2
+ */
+#include <linux/of.h>
+#include <linux/fb.h>
+#include <linux/export.h>
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+
+int of_get_video_mode(struct device_node *np, struct drm_display_mode *dmode,
+ struct fb_videomode *fbmode)
+{
+ int ret = 0;
+ u32 left_margin, xres, right_margin, hsync_len;
+ u32 upper_margin, yres, lower_margin, vsync_len;
+ u32 width_mm = 0, height_mm = 0;
+ u32 clock;
+ bool hah = false, vah = false, interlaced = false, doublescan = false;
+
+ if (!np)
+ return -EINVAL;
+
+ ret |= of_property_read_u32(np, "left-margin", &left_margin);
+ ret |= of_property_read_u32(np, "xres", &xres);
+ ret |= of_property_read_u32(np, "right-margin", &right_margin);
+ ret |= of_property_read_u32(np, "hsync-len", &hsync_len);
+ ret |= of_property_read_u32(np, "upper-margin", &upper_margin);
+ ret |= of_property_read_u32(np, "yres", &yres);
+ ret |= of_property_read_u32(np, "lower-margin", &lower_margin);
+ ret |= of_property_read_u32(np, "vsync-len", &vsync_len);
+ ret |= of_property_read_u32(np, "clock", &clock);
+ if (ret)
+ return -EINVAL;
+
+ of_property_read_u32(np, "width-mm", &width_mm);
+ of_property_read_u32(np, "height-mm", &height_mm);
+
+ hah = of_property_read_bool(np, "hsync-active-high");
+ vah = of_property_read_bool(np, "vsync-active-high");
+ interlaced = of_property_read_bool(np, "interlaced");
+ doublescan = of_property_read_bool(np, "doublescan");
+
+ if (dmode) {
+ memset(dmode, 0, sizeof(*dmode));
+
+ dmode->hdisplay = xres;
+ dmode->hsync_start = xres + right_margin;
+ dmode->hsync_end = xres + right_margin + hsync_len;
+ dmode->htotal = xres + right_margin + hsync_len + left_margin;
+
+ dmode->vdisplay = yres;
+ dmode->vsync_start = yres + lower_margin;
+ dmode->vsync_end = yres + lower_margin + vsync_len;
+ dmode->vtotal = yres + lower_margin + vsync_len + upper_margin;
+
+ dmode->width_mm = width_mm;
+ dmode->height_mm = height_mm;
+
+ dmode->clock = clock / 1000;
+
+ if (hah)
+ dmode->flags |= DRM_MODE_FLAG_PHSYNC;
+ else
+ dmode->flags |= DRM_MODE_FLAG_NHSYNC;
+ if (vah)
+ dmode->flags |= DRM_MODE_FLAG_PVSYNC;
+ else
+ dmode->flags |= DRM_MODE_FLAG_NVSYNC;
+ if (interlaced)
+ dmode->flags |= DRM_MODE_FLAG_INTERLACE;
+ if (doublescan)
+ dmode->flags |= DRM_MODE_FLAG_DBLSCAN;
+
+ drm_mode_set_name(dmode);
+ }
+
+ if (fbmode) {
+ memset(fbmode, 0, sizeof(*fbmode));
+
+ fbmode->xres = xres;
+ fbmode->left_margin = left_margin;
+ fbmode->right_margin = right_margin;
+ fbmode->hsync_len = hsync_len;
+
+ fbmode->yres = yres;
+ fbmode->upper_margin = upper_margin;
+ fbmode->lower_margin = lower_margin;
+ fbmode->vsync_len = vsync_len;
+
+ fbmode->pixclock = KHZ2PICOS(clock / 1000);
+
+ if (hah)
+ fbmode->sync |= FB_SYNC_HOR_HIGH_ACT;
+ if (vah)
+ fbmode->sync |= FB_SYNC_VERT_HIGH_ACT;
+ if (interlaced)
+ fbmode->vmode |= FB_VMODE_INTERLACED;
+ if (doublescan)
+ fbmode->vmode |= FB_VMODE_DOUBLE;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(of_get_video_mode);
diff --git a/include/linux/of_videomode.h b/include/linux/of_videomode.h
new file mode 100644
index 0000000..a988429
--- /dev/null
+++ b/include/linux/of_videomode.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright 2012 Sascha Hauer <s.hauer at pengutronix.de>
+ *
+ * OF helpers for videomodes.
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __LINUX_OF_VIDEOMODE_H
+#define __LINUX_OF_VIDEOMODE_H
+
+struct device_node;
+struct fb_videomode;
+struct drm_display_mode;
+
+int of_get_video_mode(struct device_node *np, struct drm_display_mode *dmode,
+ struct fb_videomode *fbmode);
+
+#endif /* __LINUX_OF_VIDEOMODE_H */
--
1.7.10
