1#include <linux/component.h>
  2#include <linux/export.h>
  3#include <linux/list.h>
  4#include <linux/of_graph.h>
  5#include <drm/drmP.h>
  6#include <drm/drm_crtc.h>
  7#include <drm/drm_of.h>
  8
  9/**
 10 * drm_crtc_port_mask - find the mask of a registered CRTC by port OF node
 11 * @dev: DRM device
 12 * @port: port OF node
 13 *
 14 * Given a port OF node, return the possible mask of the corresponding
 15 * CRTC within a device's list of CRTCs.  Returns zero if not found.
 16 */
 17static uint32_t drm_crtc_port_mask(struct drm_device *dev,
 18				   struct device_node *port)
 19{
 20	unsigned int index = 0;
 21	struct drm_crtc *tmp;
 22
 23	drm_for_each_crtc(tmp, dev) {
 24		if (tmp->port == port)
 25			return 1 << index;
 26
 27		index++;
 28	}
 29
 30	return 0;
 31}
 32
 33/**
 34 * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
 35 * @dev: DRM device
 36 * @port: encoder port to scan for endpoints
 37 *
 38 * Scan all endpoints attached to a port, locate their attached CRTCs,
 39 * and generate the DRM mask of CRTCs which may be attached to this
 40 * encoder.
 41 *
 42 * See Documentation/devicetree/bindings/graph.txt for the bindings.
 43 */
 44uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
 45				    struct device_node *port)
 46{
 47	struct device_node *remote_port, *ep;
 48	uint32_t possible_crtcs = 0;
 49
 50	for_each_endpoint_of_node(port, ep) {
 51		remote_port = of_graph_get_remote_port(ep);
 52		if (!remote_port) {
 53			of_node_put(ep);
 54			return 0;
 55		}
 56
 57		possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
 58
 59		of_node_put(remote_port);
 60	}
 61
 62	return possible_crtcs;
 63}
 64EXPORT_SYMBOL(drm_of_find_possible_crtcs);
 65
 66/**
 67 * drm_of_component_probe - Generic probe function for a component based master
 68 * @dev: master device containing the OF node
 69 * @compare_of: compare function used for matching components
 70 * @master_ops: component master ops to be used
 71 *
 72 * Parse the platform device OF node and bind all the components associated
 73 * with the master. Interface ports are added before the encoders in order to
 74 * satisfy their .bind requirements
 75 * See Documentation/devicetree/bindings/graph.txt for the bindings.
 76 *
 77 * Returns zero if successful, or one of the standard error codes if it fails.
 78 */
 79int drm_of_component_probe(struct device *dev,
 80			   int (*compare_of)(struct device *, void *),
 81			   const struct component_master_ops *m_ops)
 82{
 83	struct device_node *ep, *port, *remote;
 84	struct component_match *match = NULL;
 85	int i;
 86
 87	if (!dev->of_node)
 88		return -EINVAL;
 89
 90	/*
 91	 * Bind the crtc's ports first, so that drm_of_find_possible_crtcs()
 92	 * called from encoder's .bind callbacks works as expected
 93	 */
 94	for (i = 0; ; i++) {
 95		port = of_parse_phandle(dev->of_node, "ports", i);
 96		if (!port)
 97			break;
 98
 99		if (!of_device_is_available(port->parent)) {
100			of_node_put(port);
101			continue;
102		}
103
104		component_match_add(dev, &match, compare_of, port);
105		of_node_put(port);
106	}
107
108	if (i == 0) {
109		dev_err(dev, "missing 'ports' property\n");
110		return -ENODEV;
111	}
112
113	if (!match) {
114		dev_err(dev, "no available port\n");
115		return -ENODEV;
116	}
117
118	/*
119	 * For bound crtcs, bind the encoders attached to their remote endpoint
120	 */
121	for (i = 0; ; i++) {
122		port = of_parse_phandle(dev->of_node, "ports", i);
123		if (!port)
124			break;
125
126		if (!of_device_is_available(port->parent)) {
127			of_node_put(port);
128			continue;
129		}
130
131		for_each_child_of_node(port, ep) {
132			remote = of_graph_get_remote_port_parent(ep);
133			if (!remote || !of_device_is_available(remote)) {
134				of_node_put(remote);
135				continue;
136			} else if (!of_device_is_available(remote->parent)) {
137				dev_warn(dev, "parent device of %s is not available\n",
138					 remote->full_name);
139				of_node_put(remote);
140				continue;
141			}
142
143			component_match_add(dev, &match, compare_of, remote);
144			of_node_put(remote);
145		}
146		of_node_put(port);
147	}
148
149	return component_master_add_with_match(dev, m_ops, match);
150}
151EXPORT_SYMBOL(drm_of_component_probe);
152
153/*
154 * drm_of_encoder_active_endpoint - return the active encoder endpoint
155 * @node: device tree node containing encoder input ports
156 * @encoder: drm_encoder
157 *
158 * Given an encoder device node and a drm_encoder with a connected crtc,
159 * parse the encoder endpoint connecting to the crtc port.
160 */
161int drm_of_encoder_active_endpoint(struct device_node *node,
162				   struct drm_encoder *encoder,
163				   struct of_endpoint *endpoint)
164{
165	struct device_node *ep;
166	struct drm_crtc *crtc = encoder->crtc;
167	struct device_node *port;
168	int ret;
169
170	if (!node || !crtc)
171		return -EINVAL;
172
173	for_each_endpoint_of_node(node, ep) {
174		port = of_graph_get_remote_port(ep);
175		of_node_put(port);
176		if (port == crtc->port) {
177			ret = of_graph_parse_endpoint(ep, endpoint);
178			of_node_put(ep);
179			return ret;
180		}
181	}
182
183	return -EINVAL;
184}
185EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);