linux/drivers/gpu/drm/drm_of.c
Rob Herring 1f2db3034c drm: of: introduce drm_of_find_panel_or_bridge
Many drivers have a common pattern of searching the OF graph for either an
attached panel or bridge and then finding the DRM struct for the panel
or bridge. Also, most drivers need to handle deferred probing when the
DRM device is not yet instantiated. Create a common function,
drm_of_find_panel_or_bridge, to find the connected node and the
associated DRM panel or bridge device.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
[seanpaul dropped extern from drm_of.h]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
2017-04-06 17:00:27 -04:00

263 lines
6.5 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_bridge.h>
#include <drm/drm_crtc.h>
#include <drm/drm_encoder.h>
#include <drm/drm_panel.h>
#include <drm/drm_of.h>
static void drm_release_of(struct device *dev, void *data)
{
of_node_put(data);
}
/**
* 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_match_add - Add a component helper OF node match rule
* @master: master device
* @matchptr: component match pointer
* @compare: compare function used for matching component
* @node: of_node
*/
void drm_of_component_match_add(struct device *master,
struct component_match **matchptr,
int (*compare)(struct device *, void *),
struct device_node *node)
{
of_node_get(node);
component_match_add_release(master, matchptr, drm_release_of,
compare, node);
}
EXPORT_SYMBOL_GPL(drm_of_component_match_add);
/**
* 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;
}
drm_of_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;
}
drm_of_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);
/*
* drm_of_find_panel_or_bridge - return connected panel or bridge device
* @np: device tree node containing encoder output ports
* @panel: pointer to hold returned drm_panel
* @bridge: pointer to hold returned drm_bridge
*
* Given a DT node's port and endpoint number, find the connected node and
* return either the associated struct drm_panel or drm_bridge device. Either
* @panel or @bridge must not be NULL.
*
* Returns zero if successful, or one of the standard error codes if it fails.
*/
int drm_of_find_panel_or_bridge(const struct device_node *np,
int port, int endpoint,
struct drm_panel **panel,
struct drm_bridge **bridge)
{
int ret = -EPROBE_DEFER;
struct device_node *remote;
if (!panel && !bridge)
return -EINVAL;
remote = of_graph_get_remote_node(np, port, endpoint);
if (!remote)
return -ENODEV;
if (panel) {
*panel = of_drm_find_panel(remote);
if (*panel)
ret = 0;
}
/* No panel found yet, check for a bridge next. */
if (bridge) {
if (ret) {
*bridge = of_drm_find_bridge(remote);
if (*bridge)
ret = 0;
} else {
*bridge = NULL;
}
}
of_node_put(remote);
return ret;
}
EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);