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_bridge.h>
   7 #include <drm/drm_crtc.h>
   8 #include <drm/drm_encoder.h>
   9 #include <drm/drm_panel.h>
  10 #include <drm/drm_of.h>
  11
  12 static void drm_release_of(struct device *dev, void *data)
  13 {
  14         of_node_put(data);
  15 }
  16
  17 /**
  18  * drm_crtc_port_mask - find the mask of a registered CRTC by port OF node
  19  * @dev: DRM device
  20  * @port: port OF node
  21  *
  22  * Given a port OF node, return the possible mask of the corresponding
  23  * CRTC within a device's list of CRTCs.  Returns zero if not found.
  24  */
  25 static uint32_t drm_crtc_port_mask(struct drm_device *dev,
  26                                    struct device_node *port)
  27 {
  28         unsigned int index = 0;
  29         struct drm_crtc *tmp;
  30
  31         drm_for_each_crtc(tmp, dev) {
  32                 if (tmp->port == port)
  33                         return 1 << index;
  34
  35                 index++;
  36         }
  37
  38         return 0;
  39 }
  40
  41 /**
  42  * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
  43  * @dev: DRM device
  44  * @port: encoder port to scan for endpoints
  45  *
  46  * Scan all endpoints attached to a port, locate their attached CRTCs,
  47  * and generate the DRM mask of CRTCs which may be attached to this
  48  * encoder.
  49  *
  50  * See Documentation/devicetree/bindings/graph.txt for the bindings.
  51  */
  52 uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
  53                                     struct device_node *port)
  54 {
  55         struct device_node *remote_port, *ep;
  56         uint32_t possible_crtcs = 0;
  57
  58         for_each_endpoint_of_node(port, ep) {
  59                 remote_port = of_graph_get_remote_port(ep);
  60                 if (!remote_port) {
  61                         of_node_put(ep);
  62                         return 0;
  63                 }
  64
  65                 possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
  66
  67                 of_node_put(remote_port);
  68         }
  69
  70         return possible_crtcs;
  71 }
  72 EXPORT_SYMBOL(drm_of_find_possible_crtcs);
  73
  74 /**
  75  * drm_of_component_match_add - Add a component helper OF node match rule
  76  * @master: master device
  77  * @matchptr: component match pointer
  78  * @compare: compare function used for matching component
  79  * @node: of_node
  80  */
  81 void drm_of_component_match_add(struct device *master,
  82                                 struct component_match **matchptr,
  83                                 int (*compare)(struct device *, void *),
  84                                 struct device_node *node)
  85 {
  86         of_node_get(node);
  87         component_match_add_release(master, matchptr, drm_release_of,
  88                                     compare, node);
  89 }
  90 EXPORT_SYMBOL_GPL(drm_of_component_match_add);
  91
  92 /**
  93  * drm_of_component_probe - Generic probe function for a component based master
  94  * @dev: master device containing the OF node
  95  * @compare_of: compare function used for matching components
  96  * @master_ops: component master ops to be used
  97  *
  98  * Parse the platform device OF node and bind all the components associated
  99  * with the master. Interface ports are added before the encoders in order to
 100  * satisfy their .bind requirements
 101  * See Documentation/devicetree/bindings/graph.txt for the bindings.
 102  *
 103  * Returns zero if successful, or one of the standard error codes if it fails.
 104  */
 105 int drm_of_component_probe(struct device *dev,
 106                            int (*compare_of)(struct device *, void *),
 107                            const struct component_master_ops *m_ops)
 108 {
 109         struct device_node *ep, *port, *remote;
 110         struct component_match *match = NULL;
 111         int i;
 112
 113         if (!dev->of_node)
 114                 return -EINVAL;
 115
 116         /*
 117          * Bind the crtc's ports first, so that drm_of_find_possible_crtcs()
 118          * called from encoder's .bind callbacks works as expected
 119          */
 120         for (i = 0; ; i++) {
 121                 port = of_parse_phandle(dev->of_node, "ports", i);
 122                 if (!port)
 123                         break;
 124
 125                 if (!of_device_is_available(port->parent)) {
 126                         of_node_put(port);
 127                         continue;
 128                 }
 129
 130                 drm_of_component_match_add(dev, &match, compare_of, port);
 131                 of_node_put(port);
 132         }
 133
 134         if (i == 0) {
 135                 dev_err(dev, "missing 'ports' property\n");
 136                 return -ENODEV;
 137         }
 138
 139         if (!match) {
 140                 dev_err(dev, "no available port\n");
 141                 return -ENODEV;
 142         }
 143
 144         /*
 145          * For bound crtcs, bind the encoders attached to their remote endpoint
 146          */
 147         for (i = 0; ; i++) {
 148                 port = of_parse_phandle(dev->of_node, "ports", i);
 149                 if (!port)
 150                         break;
 151
 152                 if (!of_device_is_available(port->parent)) {
 153                         of_node_put(port);
 154                         continue;
 155                 }
 156
 157                 for_each_child_of_node(port, ep) {
 158                         remote = of_graph_get_remote_port_parent(ep);
 159                         if (!remote || !of_device_is_available(remote)) {
 160                                 of_node_put(remote);
 161                                 continue;
 162                         } else if (!of_device_is_available(remote->parent)) {
 163                                 dev_warn(dev, "parent device of %pOF is not available\n",
 164                                          remote);
 165                                 of_node_put(remote);
 166                                 continue;
 167                         }
 168
 169                         drm_of_component_match_add(dev, &match, compare_of,
 170                                                    remote);
 171                         of_node_put(remote);
 172                 }
 173                 of_node_put(port);
 174         }
 175
 176         return component_master_add_with_match(dev, m_ops, match);
 177 }
 178 EXPORT_SYMBOL(drm_of_component_probe);
 179
 180 /*
 181  * drm_of_encoder_active_endpoint - return the active encoder endpoint
 182  * @node: device tree node containing encoder input ports
 183  * @encoder: drm_encoder
 184  *
 185  * Given an encoder device node and a drm_encoder with a connected crtc,
 186  * parse the encoder endpoint connecting to the crtc port.
 187  */
 188 int drm_of_encoder_active_endpoint(struct device_node *node,
 189                                    struct drm_encoder *encoder,
 190                                    struct of_endpoint *endpoint)
 191 {
 192         struct device_node *ep;
 193         struct drm_crtc *crtc = encoder->crtc;
 194         struct device_node *port;
 195         int ret;
 196
 197         if (!node || !crtc)
 198                 return -EINVAL;
 199
 200         for_each_endpoint_of_node(node, ep) {
 201                 port = of_graph_get_remote_port(ep);
 202                 of_node_put(port);
 203                 if (port == crtc->port) {
 204                         ret = of_graph_parse_endpoint(ep, endpoint);
 205                         of_node_put(ep);
 206                         return ret;
 207                 }
 208         }
 209
 210         return -EINVAL;
 211 }
 212 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
 213
 214 /*
 215  * drm_of_find_panel_or_bridge - return connected panel or bridge device
 216  * @np: device tree node containing encoder output ports
 217  * @panel: pointer to hold returned drm_panel
 218  * @bridge: pointer to hold returned drm_bridge
 219  *
 220  * Given a DT node's port and endpoint number, find the connected node and
 221  * return either the associated struct drm_panel or drm_bridge device. Either
 222  * @panel or @bridge must not be NULL.
 223  *
 224  * Returns zero if successful, or one of the standard error codes if it fails.
 225  */
 226 int drm_of_find_panel_or_bridge(const struct device_node *np,
 227                                 int port, int endpoint,
 228                                 struct drm_panel **panel,
 229                                 struct drm_bridge **bridge)
 230 {
 231         int ret = -EPROBE_DEFER;
 232         struct device_node *remote;
 233
 234         if (!panel && !bridge)
 235                 return -EINVAL;
 236         if (panel)
 237                 *panel = NULL;
 238
 239         remote = of_graph_get_remote_node(np, port, endpoint);
 240         if (!remote)
 241                 return -ENODEV;
 242
 243         if (panel) {
 244                 *panel = of_drm_find_panel(remote);
 245                 if (*panel)
 246                         ret = 0;
 247         }
 248
 249         /* No panel found yet, check for a bridge next. */
 250         if (bridge) {
 251                 if (ret) {
 252                         *bridge = of_drm_find_bridge(remote);
 253                         if (*bridge)
 254                                 ret = 0;
 255                 } else {
 256                         *bridge = NULL;
 257                 }
 258
 259         }
 260
 261         of_node_put(remote);
 262         return ret;
 263 }
 264 EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);