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