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_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  */
  17 static 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  */
  44 uint32_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 }
  64 EXPORT_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  */
  79 int 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 }
 151 EXPORT_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  */
 161 int 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 }
 185 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);