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