[PATCH 22/29] video: Add display timing from devicetree helper
Sascha Hauer
s.hauer at pengutronix.de
Fri Mar 14 10:32:42 EDT 2014
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
drivers/video/Makefile | 1 +
drivers/video/of_display_timing.c | 238 ++++++++++++++++++++++++++++++++++++++
include/fb.h | 14 ++-
3 files changed, 252 insertions(+), 1 deletion(-)
create mode 100644 drivers/video/of_display_timing.c
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 31edfca..d36d83d 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -1,4 +1,5 @@
obj-$(CONFIG_VIDEO) += fb.o
+obj-$(CONFIG_OFDEVICE) += of_display_timing.o
obj-$(CONFIG_DRIVER_VIDEO_ATMEL) += atmel_lcdfb.o atmel_lcdfb_core.o
obj-$(CONFIG_DRIVER_VIDEO_ATMEL_HLCD) += atmel_hlcdfb.o atmel_lcdfb_core.o
diff --git a/drivers/video/of_display_timing.c b/drivers/video/of_display_timing.c
new file mode 100644
index 0000000..5dfd5b3
--- /dev/null
+++ b/drivers/video/of_display_timing.c
@@ -0,0 +1,238 @@
+/*
+ * OF helpers for parsing display timings
+ *
+ * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar at pengutronix.de>, Pengutronix
+ *
+ * based on of_videomode.c by Sascha Hauer <s.hauer at pengutronix.de>
+ *
+ * This file is released under the GPLv2
+ */
+#include <common.h>
+#include <of.h>
+#include <fb.h>
+#include <malloc.h>
+
+void display_timings_release(struct display_timings *disp)
+{
+ free(disp->modes);
+ free(disp);
+}
+EXPORT_SYMBOL_GPL(display_timings_release);
+
+/**
+ * parse_timing_property - parse timing_entry from device_node
+ * @np: device_node with the property
+ * @name: name of the property
+ * @result: will be set to the return value
+ *
+ * DESCRIPTION:
+ * Every display_timing can be specified with either just the typical value or
+ * a range consisting of min/typ/max. This function helps handling this
+ **/
+static int parse_timing_property(const struct device_node *np, const char *name,
+ u32 *res)
+{
+ struct property *prop;
+ int length, cells, ret;
+
+ prop = of_find_property(np, name, &length);
+ if (!prop) {
+ pr_err("%s: could not find property %s\n",
+ np->full_name, name);
+ return -EINVAL;
+ }
+
+ cells = length / sizeof(u32);
+ if (cells == 1) {
+ ret = of_property_read_u32(np, name, res);
+ } else {
+ pr_err("%s: illegal timing specification in %s\n",
+ np->full_name, name);
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+/**
+ * of_parse_display_timing - parse display_timing entry from device_node
+ * @np: device_node with the properties
+ **/
+static int of_parse_display_timing(const struct device_node *np,
+ struct fb_videomode *mode)
+{
+ u32 val = 0, pixelclock = 0;
+ int ret = 0;
+
+ memset(mode, 0, sizeof(*mode));
+
+ ret |= parse_timing_property(np, "hback-porch", &mode->left_margin);
+ ret |= parse_timing_property(np, "hfront-porch", &mode->right_margin);
+ ret |= parse_timing_property(np, "hactive", &mode->xres);
+ ret |= parse_timing_property(np, "hsync-len", &mode->hsync_len);
+ ret |= parse_timing_property(np, "vback-porch", &mode->upper_margin);
+ ret |= parse_timing_property(np, "vfront-porch", &mode->lower_margin);
+ ret |= parse_timing_property(np, "vactive", &mode->yres);
+ ret |= parse_timing_property(np, "vsync-len", &mode->vsync_len);
+ ret |= parse_timing_property(np, "clock-frequency", &pixelclock);
+
+ mode->pixclock = pixelclock ? KHZ2PICOS(pixelclock / 1000) : 0;
+
+ if (!of_property_read_u32(np, "vsync-active", &val))
+ mode->sync |= val ? FB_SYNC_VERT_HIGH_ACT : 0;
+ if (!of_property_read_u32(np, "hsync-active", &val))
+ mode->sync |= val ? FB_SYNC_HOR_HIGH_ACT : 0;
+ if (!of_property_read_u32(np, "de-active", &val))
+ mode->display_flags |= val ? DISPLAY_FLAGS_DE_HIGH :
+ DISPLAY_FLAGS_DE_LOW;
+ if (!of_property_read_u32(np, "pixelclk-active", &val))
+ mode->display_flags |= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE :
+ DISPLAY_FLAGS_PIXDATA_NEGEDGE;
+
+ if (ret) {
+ pr_err("%s: error reading timing properties\n",
+ np->full_name);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * of_get_display_timing - parse a display_timing entry
+ * @np: device_node with the timing subnode
+ * @name: name of the timing node
+ * @dt: display_timing struct to fill
+ **/
+int of_get_display_timing(struct device_node *np, const char *name,
+ struct fb_videomode *mode)
+{
+ struct device_node *timing_np;
+
+ if (!np) {
+ pr_err("%s: no devicenode given\n", np->full_name);
+ return -EINVAL;
+ }
+
+ timing_np = of_get_child_by_name(np, name);
+ if (!timing_np) {
+ pr_err("%s: could not find node '%s'\n",
+ np->full_name, name);
+ return -ENOENT;
+ }
+
+ return of_parse_display_timing(timing_np, mode);
+}
+EXPORT_SYMBOL_GPL(of_get_display_timing);
+
+/**
+ * of_get_display_timings - parse all display_timing entries from a device_node
+ * @np: device_node with the subnodes
+ **/
+struct display_timings *of_get_display_timings(struct device_node *np)
+{
+ struct device_node *timings_np;
+ struct device_node *entry;
+ struct device_node *native_mode;
+ struct display_timings *disp;
+
+ if (!np) {
+ pr_err("%s: no device node given\n", np->full_name);
+ return NULL;
+ }
+
+ timings_np = of_get_child_by_name(np, "display-timings");
+ if (!timings_np) {
+ pr_debug("%s: could not find display-timings node\n",
+ np->full_name);
+ return NULL;
+ }
+
+ disp = xzalloc(sizeof(*disp));
+
+ entry = of_parse_phandle(timings_np, "native-mode", 0);
+ /* assume first child as native mode if none provided */
+ if (!entry)
+ entry = of_get_next_available_child(np, NULL);
+ /* if there is no child, it is useless to go on */
+ if (!entry) {
+ pr_err("%s: no timing specifications given\n",
+ np->full_name);
+ goto entryfail;
+ }
+
+ pr_debug("%s: using %s as default timing\n",
+ np->full_name, entry->name);
+
+ native_mode = entry;
+
+ disp->num_modes = of_get_child_count(timings_np);
+ if (disp->num_modes == 0) {
+ /* should never happen, as entry was already found above */
+ pr_err("%s: no timings specified\n", np->full_name);
+ goto entryfail;
+ }
+
+ disp->modes = xzalloc(sizeof(struct fb_videomode) * disp->num_modes);
+
+ disp->num_modes = 0;
+ disp->native_mode = 0;
+
+ for_each_child_of_node(timings_np, entry) {
+ struct fb_videomode *mode;
+ int r;
+
+ mode = &disp->modes[disp->num_modes];
+
+ r = of_parse_display_timing(entry, mode);
+ if (r) {
+ /*
+ * to not encourage wrong devicetrees, fail in case of
+ * an error
+ */
+ pr_err("%s: error in timing %d\n",
+ np->full_name, disp->num_modes + 1);
+ goto timingfail;
+ }
+
+ mode->name = xstrdup(entry->name);
+
+ if (native_mode == entry)
+ disp->native_mode = disp->num_modes;
+
+ disp->num_modes++;
+ }
+
+ pr_debug("%s: got %d timings. Using timing #%d as default\n",
+ np->full_name, disp->num_modes,
+ disp->native_mode + 1);
+
+ return disp;
+
+timingfail:
+ display_timings_release(disp);
+entryfail:
+ free(disp);
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(of_get_display_timings);
+
+/**
+ * of_display_timings_exist - check if a display-timings node is provided
+ * @np: device_node with the timing
+ **/
+int of_display_timings_exist(struct device_node *np)
+{
+ struct device_node *timings_np;
+
+ if (!np)
+ return -EINVAL;
+
+ timings_np = of_parse_phandle(np, "display-timings", 0);
+ if (!timings_np)
+ return -EINVAL;
+
+ return 1;
+}
+EXPORT_SYMBOL_GPL(of_display_timings_exist);
diff --git a/include/fb.h b/include/fb.h
index 91d3fe4..8d255c0 100644
--- a/include/fb.h
+++ b/include/fb.h
@@ -32,6 +32,16 @@
#define PICOS2KHZ(a) (1000000000UL/(a))
#define KHZ2PICOS(a) (1000000000UL/(a))
+enum display_flags {
+ /* data enable flag */
+ DISPLAY_FLAGS_DE_LOW = BIT(4),
+ DISPLAY_FLAGS_DE_HIGH = BIT(5),
+ /* drive data on pos. edge */
+ DISPLAY_FLAGS_PIXDATA_POSEDGE = BIT(6),
+ /* drive data on neg. edge */
+ DISPLAY_FLAGS_PIXDATA_NEGEDGE = BIT(7),
+};
+
struct fb_videomode {
const char *name; /* optional */
u32 refresh; /* optional */
@@ -46,7 +56,7 @@ struct fb_videomode {
u32 vsync_len;
u32 sync;
u32 vmode;
- u32 flag;
+ u32 display_flags;
};
/* Interpretation of offset for color fields: All offsets are from the right,
@@ -125,6 +135,8 @@ struct fb_info {
*/
};
+struct display_timings *of_get_display_timings(struct device_node *np);
+
int register_framebuffer(struct fb_info *info);
#define FBIOGET_SCREENINFO _IOR('F', 1, loff_t)
--
1.9.0
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