gpu/drm/drm_of.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 #include <linux/component.h>
0003 #include <linux/export.h>
0004 #include <linux/list.h>
0005 #include <linux/media-bus-format.h>
0006 #include <linux/of.h>
0007 #include <linux/of_graph.h>
0008
0009 #include <drm/drm_bridge.h>
0010 #include <drm/drm_crtc.h>
0011 #include <drm/drm_device.h>
0012 #include <drm/drm_encoder.h>
0013 #include <drm/drm_of.h>
0014 #include <drm/drm_panel.h>
0015
0016 /**
0017  * DOC: overview
0018  *
0019  * A set of helper functions to aid DRM drivers in parsing standard DT
0020  * properties.
0021  */
0022
0023 /**
0024  * drm_of_crtc_port_mask - find the mask of a registered CRTC by port OF node
0025  * @dev: DRM device
0026  * @port: port OF node
0027  *
0028  * Given a port OF node, return the possible mask of the corresponding
0029  * CRTC within a device's list of CRTCs.  Returns zero if not found.
0030  */
0031 uint32_t drm_of_crtc_port_mask(struct drm_device *dev,
0032                 struct device_node *port)
0033 {
0034     unsigned int index = 0;
0035     struct drm_crtc *tmp;
0036
0037     drm_for_each_crtc(tmp, dev) {
0038         if (tmp->port == port)
0039             return 1 << index;
0040
0041         index++;
0042     }
0043
0044     return 0;
0045 }
0046 EXPORT_SYMBOL(drm_of_crtc_port_mask);
0047
0048 /**
0049  * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
0050  * @dev: DRM device
0051  * @port: encoder port to scan for endpoints
0052  *
0053  * Scan all endpoints attached to a port, locate their attached CRTCs,
0054  * and generate the DRM mask of CRTCs which may be attached to this
0055  * encoder.
0056  *
0057  * See Documentation/devicetree/bindings/graph.txt for the bindings.
0058  */
0059 uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
0060                     struct device_node *port)
0061 {
0062     struct device_node *remote_port, *ep;
0063     uint32_t possible_crtcs = 0;
0064
0065     for_each_endpoint_of_node(port, ep) {
0066         remote_port = of_graph_get_remote_port(ep);
0067         if (!remote_port) {
0068             of_node_put(ep);
0069             return 0;
0070         }
0071
0072         possible_crtcs |= drm_of_crtc_port_mask(dev, remote_port);
0073
0074         of_node_put(remote_port);
0075     }
0076
0077     return possible_crtcs;
0078 }
0079 EXPORT_SYMBOL(drm_of_find_possible_crtcs);
0080
0081 /**
0082  * drm_of_component_match_add - Add a component helper OF node match rule
0083  * @master: master device
0084  * @matchptr: component match pointer
0085  * @compare: compare function used for matching component
0086  * @node: of_node
0087  */
0088 void drm_of_component_match_add(struct device *master,
0089                 struct component_match **matchptr,
0090                 int (*compare)(struct device *, void *),
0091                 struct device_node *node)
0092 {
0093     of_node_get(node);
0094     component_match_add_release(master, matchptr, component_release_of,
0095                     compare, node);
0096 }
0097 EXPORT_SYMBOL_GPL(drm_of_component_match_add);
0098
0099 /**
0100  * drm_of_component_probe - Generic probe function for a component based master
0101  * @dev: master device containing the OF node
0102  * @compare_of: compare function used for matching components
0103  * @m_ops: component master ops to be used
0104  *
0105  * Parse the platform device OF node and bind all the components associated
0106  * with the master. Interface ports are added before the encoders in order to
0107  * satisfy their .bind requirements
0108  * See Documentation/devicetree/bindings/graph.txt for the bindings.
0109  *
0110  * Returns zero if successful, or one of the standard error codes if it fails.
0111  */
0112 int drm_of_component_probe(struct device *dev,
0113                int (*compare_of)(struct device *, void *),
0114                const struct component_master_ops *m_ops)
0115 {
0116     struct device_node *ep, *port, *remote;
0117     struct component_match *match = NULL;
0118     int i;
0119
0120     if (!dev->of_node)
0121         return -EINVAL;
0122
0123     /*
0124      * Bind the crtc's ports first, so that drm_of_find_possible_crtcs()
0125      * called from encoder's .bind callbacks works as expected
0126      */
0127     for (i = 0; ; i++) {
0128         port = of_parse_phandle(dev->of_node, "ports", i);
0129         if (!port)
0130             break;
0131
0132         if (of_device_is_available(port->parent))
0133             drm_of_component_match_add(dev, &match, compare_of,
0134                            port);
0135
0136         of_node_put(port);
0137     }
0138
0139     if (i == 0) {
0140         dev_err(dev, "missing 'ports' property\n");
0141         return -ENODEV;
0142     }
0143
0144     if (!match) {
0145         dev_err(dev, "no available port\n");
0146         return -ENODEV;
0147     }
0148
0149     /*
0150      * For bound crtcs, bind the encoders attached to their remote endpoint
0151      */
0152     for (i = 0; ; i++) {
0153         port = of_parse_phandle(dev->of_node, "ports", i);
0154         if (!port)
0155             break;
0156
0157         if (!of_device_is_available(port->parent)) {
0158             of_node_put(port);
0159             continue;
0160         }
0161
0162         for_each_child_of_node(port, ep) {
0163             remote = of_graph_get_remote_port_parent(ep);
0164             if (!remote || !of_device_is_available(remote)) {
0165                 of_node_put(remote);
0166                 continue;
0167             } else if (!of_device_is_available(remote->parent)) {
0168                 dev_warn(dev, "parent device of %pOF is not available\n",
0169                      remote);
0170                 of_node_put(remote);
0171                 continue;
0172             }
0173
0174             drm_of_component_match_add(dev, &match, compare_of,
0175                            remote);
0176             of_node_put(remote);
0177         }
0178         of_node_put(port);
0179     }
0180
0181     return component_master_add_with_match(dev, m_ops, match);
0182 }
0183 EXPORT_SYMBOL(drm_of_component_probe);
0184
0185 /*
0186  * drm_of_encoder_active_endpoint - return the active encoder endpoint
0187  * @node: device tree node containing encoder input ports
0188  * @encoder: drm_encoder
0189  *
0190  * Given an encoder device node and a drm_encoder with a connected crtc,
0191  * parse the encoder endpoint connecting to the crtc port.
0192  */
0193 int drm_of_encoder_active_endpoint(struct device_node *node,
0194                    struct drm_encoder *encoder,
0195                    struct of_endpoint *endpoint)
0196 {
0197     struct device_node *ep;
0198     struct drm_crtc *crtc = encoder->crtc;
0199     struct device_node *port;
0200     int ret;
0201
0202     if (!node || !crtc)
0203         return -EINVAL;
0204
0205     for_each_endpoint_of_node(node, ep) {
0206         port = of_graph_get_remote_port(ep);
0207         of_node_put(port);
0208         if (port == crtc->port) {
0209             ret = of_graph_parse_endpoint(ep, endpoint);
0210             of_node_put(ep);
0211             return ret;
0212         }
0213     }
0214
0215     return -EINVAL;
0216 }
0217 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
0218
0219 /**
0220  * drm_of_find_panel_or_bridge - return connected panel or bridge device
0221  * @np: device tree node containing encoder output ports
0222  * @port: port in the device tree node
0223  * @endpoint: endpoint in the device tree node
0224  * @panel: pointer to hold returned drm_panel
0225  * @bridge: pointer to hold returned drm_bridge
0226  *
0227  * Given a DT node's port and endpoint number, find the connected node and
0228  * return either the associated struct drm_panel or drm_bridge device. Either
0229  * @panel or @bridge must not be NULL.
0230  *
0231  * This function is deprecated and should not be used in new drivers. Use
0232  * devm_drm_of_get_bridge() instead.
0233  *
0234  * Returns zero if successful, or one of the standard error codes if it fails.
0235  */
0236 int drm_of_find_panel_or_bridge(const struct device_node *np,
0237                 int port, int endpoint,
0238                 struct drm_panel **panel,
0239                 struct drm_bridge **bridge)
0240 {
0241     int ret = -EPROBE_DEFER;
0242     struct device_node *remote;
0243
0244     if (!panel && !bridge)
0245         return -EINVAL;
0246     if (panel)
0247         *panel = NULL;
0248
0249     /*
0250      * of_graph_get_remote_node() produces a noisy error message if port
0251      * node isn't found and the absence of the port is a legit case here,
0252      * so at first we silently check whether graph presents in the
0253      * device-tree node.
0254      */
0255     if (!of_graph_is_present(np))
0256         return -ENODEV;
0257
0258     remote = of_graph_get_remote_node(np, port, endpoint);
0259     if (!remote)
0260         return -ENODEV;
0261
0262     if (panel) {
0263         *panel = of_drm_find_panel(remote);
0264         if (!IS_ERR(*panel))
0265             ret = 0;
0266         else
0267             *panel = NULL;
0268     }
0269
0270     /* No panel found yet, check for a bridge next. */
0271     if (bridge) {
0272         if (ret) {
0273             *bridge = of_drm_find_bridge(remote);
0274             if (*bridge)
0275                 ret = 0;
0276         } else {
0277             *bridge = NULL;
0278         }
0279
0280     }
0281
0282     of_node_put(remote);
0283     return ret;
0284 }
0285 EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);
0286
0287 enum drm_of_lvds_pixels {
0288     DRM_OF_LVDS_EVEN = BIT(0),
0289     DRM_OF_LVDS_ODD = BIT(1),
0290 };
0291
0292 static int drm_of_lvds_get_port_pixels_type(struct device_node *port_node)
0293 {
0294     bool even_pixels =
0295         of_property_read_bool(port_node, "dual-lvds-even-pixels");
0296     bool odd_pixels =
0297         of_property_read_bool(port_node, "dual-lvds-odd-pixels");
0298
0299     return (even_pixels ? DRM_OF_LVDS_EVEN : 0) |
0300            (odd_pixels ? DRM_OF_LVDS_ODD : 0);
0301 }
0302
0303 static int drm_of_lvds_get_remote_pixels_type(
0304             const struct device_node *port_node)
0305 {
0306     struct device_node *endpoint = NULL;
0307     int pixels_type = -EPIPE;
0308
0309     for_each_child_of_node(port_node, endpoint) {
0310         struct device_node *remote_port;
0311         int current_pt;
0312
0313         if (!of_node_name_eq(endpoint, "endpoint"))
0314             continue;
0315
0316         remote_port = of_graph_get_remote_port(endpoint);
0317         if (!remote_port) {
0318             of_node_put(endpoint);
0319             return -EPIPE;
0320         }
0321
0322         current_pt = drm_of_lvds_get_port_pixels_type(remote_port);
0323         of_node_put(remote_port);
0324         if (pixels_type < 0)
0325             pixels_type = current_pt;
0326
0327         /*
0328          * Sanity check, ensure that all remote endpoints have the same
0329          * pixel type. We may lift this restriction later if we need to
0330          * support multiple sinks with different dual-link
0331          * configurations by passing the endpoints explicitly to
0332          * drm_of_lvds_get_dual_link_pixel_order().
0333          */
0334         if (!current_pt || pixels_type != current_pt) {
0335             of_node_put(endpoint);
0336             return -EINVAL;
0337         }
0338     }
0339
0340     return pixels_type;
0341 }
0342
0343 /**
0344  * drm_of_lvds_get_dual_link_pixel_order - Get LVDS dual-link pixel order
0345  * @port1: First DT port node of the Dual-link LVDS source
0346  * @port2: Second DT port node of the Dual-link LVDS source
0347  *
0348  * An LVDS dual-link connection is made of two links, with even pixels
0349  * transitting on one link, and odd pixels on the other link. This function
0350  * returns, for two ports of an LVDS dual-link source, which port shall transmit
0351  * the even and odd pixels, based on the requirements of the connected sink.
0352  *
0353  * The pixel order is determined from the dual-lvds-even-pixels and
0354  * dual-lvds-odd-pixels properties in the sink's DT port nodes. If those
0355  * properties are not present, or if their usage is not valid, this function
0356  * returns -EINVAL.
0357  *
0358  * If either port is not connected, this function returns -EPIPE.
0359  *
0360  * @port1 and @port2 are typically DT sibling nodes, but may have different
0361  * parents when, for instance, two separate LVDS encoders carry the even and odd
0362  * pixels.
0363  *
0364  * Return:
0365  * * DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS - @port1 carries even pixels and @port2
0366  *   carries odd pixels
0367  * * DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS - @port1 carries odd pixels and @port2
0368  *   carries even pixels
0369  * * -EINVAL - @port1 and @port2 are not connected to a dual-link LVDS sink, or
0370  *   the sink configuration is invalid
0371  * * -EPIPE - when @port1 or @port2 are not connected
0372  */
0373 int drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1,
0374                       const struct device_node *port2)
0375 {
0376     int remote_p1_pt, remote_p2_pt;
0377
0378     if (!port1 || !port2)
0379         return -EINVAL;
0380
0381     remote_p1_pt = drm_of_lvds_get_remote_pixels_type(port1);
0382     if (remote_p1_pt < 0)
0383         return remote_p1_pt;
0384
0385     remote_p2_pt = drm_of_lvds_get_remote_pixels_type(port2);
0386     if (remote_p2_pt < 0)
0387         return remote_p2_pt;
0388
0389     /*
0390      * A valid dual-lVDS bus is found when one remote port is marked with
0391      * "dual-lvds-even-pixels", and the other remote port is marked with
0392      * "dual-lvds-odd-pixels", bail out if the markers are not right.
0393      */
0394     if (remote_p1_pt + remote_p2_pt != DRM_OF_LVDS_EVEN + DRM_OF_LVDS_ODD)
0395         return -EINVAL;
0396
0397     return remote_p1_pt == DRM_OF_LVDS_EVEN ?
0398         DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS :
0399         DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
0400 }
0401 EXPORT_SYMBOL_GPL(drm_of_lvds_get_dual_link_pixel_order);
0402
0403 /**
0404  * drm_of_lvds_get_data_mapping - Get LVDS data mapping
0405  * @port: DT port node of the LVDS source or sink
0406  *
0407  * Convert DT "data-mapping" property string value into media bus format value.
0408  *
0409  * Return:
0410  * * MEDIA_BUS_FMT_RGB666_1X7X3_SPWG - data-mapping is "jeida-18"
0411  * * MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA - data-mapping is "jeida-24"
0412  * * MEDIA_BUS_FMT_RGB888_1X7X4_SPWG - data-mapping is "vesa-24"
0413  * * -EINVAL - the "data-mapping" property is unsupported
0414  * * -ENODEV - the "data-mapping" property is missing
0415  */
0416 int drm_of_lvds_get_data_mapping(const struct device_node *port)
0417 {
0418     const char *mapping;
0419     int ret;
0420
0421     ret = of_property_read_string(port, "data-mapping", &mapping);
0422     if (ret < 0)
0423         return -ENODEV;
0424
0425     if (!strcmp(mapping, "jeida-18"))
0426         return MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
0427     if (!strcmp(mapping, "jeida-24"))
0428         return MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
0429     if (!strcmp(mapping, "vesa-24"))
0430         return MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
0431
0432     return -EINVAL;
0433 }
0434 EXPORT_SYMBOL_GPL(drm_of_lvds_get_data_mapping);
0435
0436 /**
0437  * drm_of_get_data_lanes_count - Get DSI/(e)DP data lane count
0438  * @endpoint: DT endpoint node of the DSI/(e)DP source or sink
0439  * @min: minimum supported number of data lanes
0440  * @max: maximum supported number of data lanes
0441  *
0442  * Count DT "data-lanes" property elements and check for validity.
0443  *
0444  * Return:
0445  * * min..max - positive integer count of "data-lanes" elements
0446  * * -ve - the "data-lanes" property is missing or invalid
0447  * * -EINVAL - the "data-lanes" property is unsupported
0448  */
0449 int drm_of_get_data_lanes_count(const struct device_node *endpoint,
0450                 const unsigned int min, const unsigned int max)
0451 {
0452     int ret;
0453
0454     ret = of_property_count_u32_elems(endpoint, "data-lanes");
0455     if (ret < 0)
0456         return ret;
0457
0458     if (ret < min || ret > max)
0459         return -EINVAL;
0460
0461     return ret;
0462 }
0463 EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count);
0464
0465 /**
0466  * drm_of_get_data_lanes_count_ep - Get DSI/(e)DP data lane count by endpoint
0467  * @port: DT port node of the DSI/(e)DP source or sink
0468  * @port_reg: identifier (value of reg property) of the parent port node
0469  * @reg: identifier (value of reg property) of the endpoint node
0470  * @min: minimum supported number of data lanes
0471  * @max: maximum supported number of data lanes
0472  *
0473  * Count DT "data-lanes" property elements and check for validity.
0474  * This variant uses endpoint specifier.
0475  *
0476  * Return:
0477  * * min..max - positive integer count of "data-lanes" elements
0478  * * -EINVAL - the "data-mapping" property is unsupported
0479  * * -ENODEV - the "data-mapping" property is missing
0480  */
0481 int drm_of_get_data_lanes_count_ep(const struct device_node *port,
0482                    int port_reg, int reg,
0483                    const unsigned int min,
0484                    const unsigned int max)
0485 {
0486     struct device_node *endpoint;
0487     int ret;
0488
0489     endpoint = of_graph_get_endpoint_by_regs(port, port_reg, reg);
0490     ret = drm_of_get_data_lanes_count(endpoint, min, max);
0491     of_node_put(endpoint);
0492
0493     return ret;
0494 }
0495 EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count_ep);