drivers/gpu/drm/drm_of.c

   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_encoder.h>
   8 #include <drm/drm_of.h>
   9
  10 static void drm_release_of(struct device *dev, void *data)
  11 {
  12         of_node_put(data);
  13 }
  14
  15 /**
  16  * drm_crtc_port_mask - find the mask of a registered CRTC by port OF node
  17  * @dev: DRM device
  18  * @port: port OF node
  19  *
  20  * Given a port OF node, return the possible mask of the corresponding
  21  * CRTC within a device's list of CRTCs.  Returns zero if not found.
  22  */
  23 static uint32_t drm_crtc_port_mask(struct drm_device *dev,
  24                                    struct device_node *port)
  25 {
  26         unsigned int index = 0;
  27         struct drm_crtc *tmp;
  28
  29         drm_for_each_crtc(tmp, dev) {
  30                 if (tmp->port == port)
  31                         return 1 << index;
  32
  33                 index++;
  34         }
  35
  36         return 0;
  37 }
  38
  39 /**
  40  * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
  41  * @dev: DRM device
  42  * @port: encoder port to scan for endpoints
  43  *
  44  * Scan all endpoints attached to a port, locate their attached CRTCs,
  45  * and generate the DRM mask of CRTCs which may be attached to this
  46  * encoder.
  47  *
  48  * See Documentation/devicetree/bindings/graph.txt for the bindings.
  49  */
  50 uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
  51                                     struct device_node *port)
  52 {
  53         struct device_node *remote_port, *ep;
  54         uint32_t possible_crtcs = 0;
  55
  56         for_each_endpoint_of_node(port, ep) {
  57                 remote_port = of_graph_get_remote_port(ep);
  58                 if (!remote_port) {
  59                         of_node_put(ep);
  60                         return 0;
  61                 }
  62
  63                 possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
  64
  65                 of_node_put(remote_port);
  66         }
  67
  68         return possible_crtcs;
  69 }
  70 EXPORT_SYMBOL(drm_of_find_possible_crtcs);
  71
  72 /**
  73  * drm_of_component_match_add - Add a component helper OF node match rule
  74  * @master: master device
  75  * @matchptr: component match pointer
  76  * @compare: compare function used for matching component
  77  * @node: of_node
  78  */
  79 void drm_of_component_match_add(struct device *master,
  80                                 struct component_match **matchptr,
  81                                 int (*compare)(struct device *, void *),
  82                                 struct device_node *node)
  83 {
  84         of_node_get(node);
  85         component_match_add_release(master, matchptr, drm_release_of,
  86                                     compare, node);
  87 }
  88 EXPORT_SYMBOL_GPL(drm_of_component_match_add);
  89
  90 /**
  91  * drm_of_component_probe - Generic probe function for a component based master
  92  * @dev: master device containing the OF node
  93  * @compare_of: compare function used for matching components
  94  * @master_ops: component master ops to be used
  95  *
  96  * Parse the platform device OF node and bind all the components associated
  97  * with the master. Interface ports are added before the encoders in order to
  98  * satisfy their .bind requirements
  99  * See Documentation/devicetree/bindings/graph.txt for the bindings.
 100  *
 101  * Returns zero if successful, or one of the standard error codes if it fails.
 102  */
 103 int drm_of_component_probe(struct device *dev,
 104                            int (*compare_of)(struct device *, void *),
 105                            const struct component_master_ops *m_ops)
 106 {
 107         struct device_node *ep, *port, *remote;
 108         struct component_match *match = NULL;
 109         int i;
 110
 111         if (!dev->of_node)
 112                 return -EINVAL;
 113
 114         /*
 115          * Bind the crtc's ports first, so that drm_of_find_possible_crtcs()
 116          * called from encoder's .bind callbacks works as expected
 117          */
 118         for (i = 0; ; i++) {
 119                 port = of_parse_phandle(dev->of_node, "ports", i);
 120                 if (!port)
 121                         break;
 122
 123                 if (!of_device_is_available(port->parent)) {
 124                         of_node_put(port);
 125                         continue;
 126                 }
 127
 128                 drm_of_component_match_add(dev, &match, compare_of, port);
 129                 of_node_put(port);
 130         }
 131
 132         if (i == 0) {
 133                 dev_err(dev, "missing 'ports' property\n");
 134                 return -ENODEV;
 135         }
 136
 137         if (!match) {
 138                 dev_err(dev, "no available port\n");
 139                 return -ENODEV;
 140         }
 141
 142         /*
 143          * For bound crtcs, bind the encoders attached to their remote endpoint
 144          */
 145         for (i = 0; ; i++) {
 146                 port = of_parse_phandle(dev->of_node, "ports", i);
 147                 if (!port)
 148                         break;
 149
 150                 if (!of_device_is_available(port->parent)) {
 151                         of_node_put(port);
 152                         continue;
 153                 }
 154
 155                 for_each_child_of_node(port, ep) {
 156                         remote = of_graph_get_remote_port_parent(ep);
 157                         if (!remote || !of_device_is_available(remote)) {
 158                                 of_node_put(remote);
 159                                 continue;
 160                         } else if (!of_device_is_available(remote->parent)) {
 161                                 dev_warn(dev, "parent device of %s is not available\n",
 162                                          remote->full_name);
 163                                 of_node_put(remote);
 164                                 continue;
 165                         }
 166
 167                         drm_of_component_match_add(dev, &match, compare_of,
 168                                                    remote);
 169                         of_node_put(remote);
 170                 }
 171                 of_node_put(port);
 172         }
 173
 174         return component_master_add_with_match(dev, m_ops, match);
 175 }
 176 EXPORT_SYMBOL(drm_of_component_probe);
 177
 178 /*
 179  * drm_of_encoder_active_endpoint - return the active encoder endpoint
 180  * @node: device tree node containing encoder input ports
 181  * @encoder: drm_encoder
 182  *
 183  * Given an encoder device node and a drm_encoder with a connected crtc,
 184  * parse the encoder endpoint connecting to the crtc port.
 185  */
 186 int drm_of_encoder_active_endpoint(struct device_node *node,
 187                                    struct drm_encoder *encoder,
 188                                    struct of_endpoint *endpoint)
 189 {
 190         struct device_node *ep;
 191         struct drm_crtc *crtc = encoder->crtc;
 192         struct device_node *port;
 193         int ret;
 194
 195         if (!node || !crtc)
 196                 return -EINVAL;
 197
 198         for_each_endpoint_of_node(node, ep) {
 199                 port = of_graph_get_remote_port(ep);
 200                 of_node_put(port);
 201                 if (port == crtc->port) {
 202                         ret = of_graph_parse_endpoint(ep, endpoint);
 203                         of_node_put(ep);
 204                         return ret;
 205                 }
 206         }
 207
 208         return -EINVAL;
 209 }
 210 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);