linux/drivers/gpu/drm/drm_of.c
Daniel Vetter 7f9e7ec92b drm/doc: Include drm_of.c helpers
Fixes a dead link I spotted in the struct drm_crtc docs. Comments
themselves are in a surprisingly good state.

v2: Fix subject typo (Sean).

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180709084016.23750-14-daniel.vetter@ffwll.ch
2018-07-13 18:40:28 +02:00

278 lines
6.7 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>
/**
* DOC: overview
*
* A set of helper functions to aid DRM drivers in parsing standard DT
* properties.
*/
static void drm_release_of(struct device *dev, void *data)
{
of_node_put(data);
}
/**
* drm_of_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.
*/
uint32_t drm_of_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;
}
EXPORT_SYMBOL(drm_of_crtc_port_mask);
/**
* 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_of_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
* @m_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))
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 %pOF is not available\n",
remote);
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;
if (panel)
*panel = NULL;
remote = of_graph_get_remote_node(np, port, endpoint);
if (!remote)
return -ENODEV;
if (!of_device_is_available(remote)) {
of_node_put(remote);
return -ENODEV;
}
if (panel) {
*panel = of_drm_find_panel(remote);
if (!IS_ERR(*panel))
ret = 0;
else
*panel = NULL;
}
/* 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);