linux/drivers/gpu/drm/omapdrm/dss/dss-of.c

83 lines
2.0 KiB
C

/*
* Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
* Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/seq_file.h>
#include "omapdss.h"
static struct device_node *
dss_of_port_get_parent_device(struct device_node *port)
{
struct device_node *np;
int i;
if (!port)
return NULL;
np = of_get_parent(port);
for (i = 0; i < 2 && np; ++i) {
struct property *prop;
prop = of_find_property(np, "compatible", NULL);
if (prop)
return np;
np = of_get_next_parent(np);
}
return NULL;
}
struct omap_dss_device *
omapdss_of_find_connected_device(struct device_node *node, unsigned int port)
{
struct device_node *src_node;
struct device_node *src_port;
struct device_node *ep;
struct omap_dss_device *src;
u32 port_number = 0;
/* Get the endpoint... */
ep = of_graph_get_endpoint_by_regs(node, port, 0);
if (!ep)
return NULL;
/* ... and its remote port... */
src_port = of_graph_get_remote_port(ep);
of_node_put(ep);
if (!src_port)
return NULL;
/* ... and the remote port's number and parent... */
of_property_read_u32(src_port, "reg", &port_number);
src_node = dss_of_port_get_parent_device(src_port);
of_node_put(src_port);
if (!src_node)
return ERR_PTR(-EINVAL);
/* ... and finally the connected device. */
src = omapdss_find_device_by_port(src_node, port_number);
of_node_put(src_node);
return src ? src : ERR_PTR(-EPROBE_DEFER);
}
EXPORT_SYMBOL_GPL(omapdss_of_find_connected_device);