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/*
* OF helpers for parsing display timings
*
* Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
*
* based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de>
*
* This file is released under the GPLv2
*/
#include <linux/export.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <video/display_timing.h>
#include <video/of_display_timing.h>
/**
* 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,
struct timing_entry *result)
{
struct property *prop;
int length, cells, ret;
prop = of_find_property(np, name, &length);
if (!prop) {
pr_err("%pOF: could not find property %s\n", np, name);
return -EINVAL;
}
cells = length / sizeof(u32);
if (cells == 1) {
ret = of_property_read_u32(np, name, &result->typ);
result->min = result->typ;
result->max = result->typ;
} else if (cells == 3) {
ret = of_property_read_u32_array(np, name, &result->min, cells);
} else {
pr_err("%pOF: illegal timing specification in %s\n", np, 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 display_timing *dt)
{
u32 val = 0;
int ret = 0;
memset(dt, 0, sizeof(*dt));
ret |= parse_timing_property(np, "hback-porch", &dt->hback_porch);
ret |= parse_timing_property(np, "hfront-porch", &dt->hfront_porch);
ret |= parse_timing_property(np, "hactive", &dt->hactive);
ret |= parse_timing_property(np, "hsync-len", &dt->hsync_len);
ret |= parse_timing_property(np, "vback-porch", &dt->vback_porch);
ret |= parse_timing_property(np, "vfront-porch", &dt->vfront_porch);
ret |= parse_timing_property(np, "vactive", &dt->vactive);
ret |= parse_timing_property(np, "vsync-len", &dt->vsync_len);
ret |= parse_timing_property(np, "clock-frequency", &dt->pixelclock);
dt->flags = 0;
if (!of_property_read_u32(np, "vsync-active", &val))
dt->flags |= val ? DISPLAY_FLAGS_VSYNC_HIGH :
DISPLAY_FLAGS_VSYNC_LOW;
if (!of_property_read_u32(np, "hsync-active", &val))
dt->flags |= val ? DISPLAY_FLAGS_HSYNC_HIGH :
DISPLAY_FLAGS_HSYNC_LOW;
if (!of_property_read_u32(np, "de-active", &val))
dt->flags |= val ? DISPLAY_FLAGS_DE_HIGH :
DISPLAY_FLAGS_DE_LOW;
if (!of_property_read_u32(np, "pixelclk-active", &val))
dt->flags |= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE :
DISPLAY_FLAGS_PIXDATA_NEGEDGE;
if (!of_property_read_u32(np, "syncclk-active", &val))
dt->flags |= val ? DISPLAY_FLAGS_SYNC_POSEDGE :
DISPLAY_FLAGS_SYNC_NEGEDGE;
else if (dt->flags & (DISPLAY_FLAGS_PIXDATA_POSEDGE |
DISPLAY_FLAGS_PIXDATA_NEGEDGE))
dt->flags |= dt->flags & DISPLAY_FLAGS_PIXDATA_POSEDGE ?
DISPLAY_FLAGS_SYNC_POSEDGE :
DISPLAY_FLAGS_SYNC_NEGEDGE;
if (of_property_read_bool(np, "interlaced"))
dt->flags |= DISPLAY_FLAGS_INTERLACED;
if (of_property_read_bool(np, "doublescan"))
dt->flags |= DISPLAY_FLAGS_DOUBLESCAN;
if (of_property_read_bool(np, "doubleclk"))
dt->flags |= DISPLAY_FLAGS_DOUBLECLK;
if (ret) {
pr_err("%pOF: error reading timing properties\n", np);
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(const struct device_node *np, const char *name,
struct display_timing *dt)
{
struct device_node *timing_np;
if (!np)
return -EINVAL;
timing_np = of_get_child_by_name(np, name);
if (!timing_np) {
pr_err("%pOF: could not find node '%s'\n", np, name);
return -ENOENT;
}
return of_parse_display_timing(timing_np, dt);
}
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(const struct device_node *np)
{
struct device_node *timings_np;
struct device_node *entry;
struct device_node *native_mode;
struct display_timings *disp;
if (!np)
return NULL;
timings_np = of_get_child_by_name(np, "display-timings");
if (!timings_np) {
pr_err("%pOF: could not find display-timings node\n", np);
return NULL;
}
disp = kzalloc(sizeof(*disp), GFP_KERNEL);
if (!disp) {
pr_err("%pOF: could not allocate struct disp'\n", np);
goto dispfail;
}
entry = of_parse_phandle(timings_np, "native-mode", 0);
/* assume first child as native mode if none provided */
if (!entry)
entry = of_get_next_child(timings_np, NULL);
/* if there is no child, it is useless to go on */
if (!entry) {
pr_err("%pOF: no timing specifications given\n", np);
goto entryfail;
}
pr_debug("%pOF: using %s as default timing\n", np, entry->name);
native_mode = entry;
disp->num_timings = of_get_child_count(timings_np);
if (disp->num_timings == 0) {
/* should never happen, as entry was already found above */
pr_err("%pOF: no timings specified\n", np);
goto entryfail;
}
disp->timings = kcalloc(disp->num_timings,
sizeof(struct display_timing *),
GFP_KERNEL);
if (!disp->timings) {
pr_err("%pOF: could not allocate timings array\n", np);
goto entryfail;
}
disp->num_timings = 0;
disp->native_mode = 0;
for_each_child_of_node(timings_np, entry) {
struct display_timing *dt;
int r;
dt = kzalloc(sizeof(*dt), GFP_KERNEL);
if (!dt) {
pr_err("%pOF: could not allocate display_timing struct\n",
np);
goto timingfail;
}
r = of_parse_display_timing(entry, dt);
if (r) {
/*
* to not encourage wrong devicetrees, fail in case of
* an error
*/
pr_err("%pOF: error in timing %d\n",
np, disp->num_timings + 1);
kfree(dt);
goto timingfail;
}
if (native_mode == entry)
disp->native_mode = disp->num_timings;
disp->timings[disp->num_timings] = dt;
disp->num_timings++;
}
of_node_put(timings_np);
/*
* native_mode points to the device_node returned by of_parse_phandle
* therefore call of_node_put on it
*/
of_node_put(native_mode);
pr_debug("%pOF: got %d timings. Using timing #%d as default\n",
np, disp->num_timings,
disp->native_mode + 1);
return disp;
timingfail:
of_node_put(native_mode);
display_timings_release(disp);
disp = NULL;
entryfail:
kfree(disp);
dispfail:
of_node_put(timings_np);
return NULL;
}
EXPORT_SYMBOL_GPL(of_get_display_timings);
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