linux-stable/drivers/gpu/drm/drm_of.c
Philipp Zabel 4cacf91fcb drm: add drm_of_encoder_active_endpoint helpers
This patch adds a helper to parse the encoder endpoint connected to the
encoder's crtc and two helpers to return its id and port id.

This can be used to determine input mux setting from endpoint or port ids.

Suggested-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-02-10 14:19:21 +01:00

185 lines
4.6 KiB
C

#include <linux/component.h>
#include <linux/export.h>
#include <linux/list.h>
#include <linux/of_graph.h>
#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_of.h>
/**
* drm_crtc_port_mask - find the mask of a registered CRTC by port OF node
* @dev: DRM device
* @port: port OF node
*
* Given a port OF node, return the possible mask of the corresponding
* CRTC within a device's list of CRTCs. Returns zero if not found.
*/
static uint32_t drm_crtc_port_mask(struct drm_device *dev,
struct device_node *port)
{
unsigned int index = 0;
struct drm_crtc *tmp;
drm_for_each_crtc(tmp, dev) {
if (tmp->port == port)
return 1 << index;
index++;
}
return 0;
}
/**
* drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
* @dev: DRM device
* @port: encoder port to scan for endpoints
*
* Scan all endpoints attached to a port, locate their attached CRTCs,
* and generate the DRM mask of CRTCs which may be attached to this
* encoder.
*
* See Documentation/devicetree/bindings/graph.txt for the bindings.
*/
uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
struct device_node *port)
{
struct device_node *remote_port, *ep;
uint32_t possible_crtcs = 0;
for_each_endpoint_of_node(port, ep) {
remote_port = of_graph_get_remote_port(ep);
if (!remote_port) {
of_node_put(ep);
return 0;
}
possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
of_node_put(remote_port);
}
return possible_crtcs;
}
EXPORT_SYMBOL(drm_of_find_possible_crtcs);
/**
* drm_of_component_probe - Generic probe function for a component based master
* @dev: master device containing the OF node
* @compare_of: compare function used for matching components
* @master_ops: component master ops to be used
*
* Parse the platform device OF node and bind all the components associated
* with the master. Interface ports are added before the encoders in order to
* satisfy their .bind requirements
* See Documentation/devicetree/bindings/graph.txt for the bindings.
*
* Returns zero if successful, or one of the standard error codes if it fails.
*/
int drm_of_component_probe(struct device *dev,
int (*compare_of)(struct device *, void *),
const struct component_master_ops *m_ops)
{
struct device_node *ep, *port, *remote;
struct component_match *match = NULL;
int i;
if (!dev->of_node)
return -EINVAL;
/*
* Bind the crtc's ports first, so that drm_of_find_possible_crtcs()
* called from encoder's .bind callbacks works as expected
*/
for (i = 0; ; i++) {
port = of_parse_phandle(dev->of_node, "ports", i);
if (!port)
break;
if (!of_device_is_available(port->parent)) {
of_node_put(port);
continue;
}
component_match_add(dev, &match, compare_of, port);
of_node_put(port);
}
if (i == 0) {
dev_err(dev, "missing 'ports' property\n");
return -ENODEV;
}
if (!match) {
dev_err(dev, "no available port\n");
return -ENODEV;
}
/*
* For bound crtcs, bind the encoders attached to their remote endpoint
*/
for (i = 0; ; i++) {
port = of_parse_phandle(dev->of_node, "ports", i);
if (!port)
break;
if (!of_device_is_available(port->parent)) {
of_node_put(port);
continue;
}
for_each_child_of_node(port, ep) {
remote = of_graph_get_remote_port_parent(ep);
if (!remote || !of_device_is_available(remote)) {
of_node_put(remote);
continue;
} else if (!of_device_is_available(remote->parent)) {
dev_warn(dev, "parent device of %s is not available\n",
remote->full_name);
of_node_put(remote);
continue;
}
component_match_add(dev, &match, compare_of, remote);
of_node_put(remote);
}
of_node_put(port);
}
return component_master_add_with_match(dev, m_ops, match);
}
EXPORT_SYMBOL(drm_of_component_probe);
/*
* drm_of_encoder_active_endpoint - return the active encoder endpoint
* @node: device tree node containing encoder input ports
* @encoder: drm_encoder
*
* Given an encoder device node and a drm_encoder with a connected crtc,
* parse the encoder endpoint connecting to the crtc port.
*/
int drm_of_encoder_active_endpoint(struct device_node *node,
struct drm_encoder *encoder,
struct of_endpoint *endpoint)
{
struct device_node *ep;
struct drm_crtc *crtc = encoder->crtc;
struct device_node *port;
int ret;
if (!node || !crtc)
return -EINVAL;
for_each_endpoint_of_node(node, ep) {
port = of_graph_get_remote_port(ep);
of_node_put(port);
if (port == crtc->port) {
ret = of_graph_parse_endpoint(ep, endpoint);
of_node_put(ep);
return ret;
}
}
return -EINVAL;
}
EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);