// SPDX-License-Identifier: GPL-2.0-only #include <linux/component.h> #include <linux/export.h> #include <linux/list.h> #include <linux/media-bus-format.h> #include <linux/of.h> #include <linux/of_graph.h> #include <drm/drm_bridge.h> #include <drm/drm_crtc.h> #include <drm/drm_device.h> #include <drm/drm_encoder.h> #include <drm/drm_mipi_dsi.h> #include <drm/drm_of.h> #include <drm/drm_panel.h> /** * DOC: overview * * A set of helper functions to aid DRM drivers in parsing standard DT * properties. */ /** * drm_of_crtc_port_mask - find the mask of a registered CRTC by port OF node * @dev: DRM device * @port: port OF node * * Given a port OF node, return the possible mask of the corresponding * CRTC within a device's list of CRTCs. Returns zero if not found. */ uint32_t drm_of_crtc_port_mask(struct drm_device *dev, struct device_node *port) { unsigned int index = 0; struct drm_crtc *tmp; drm_for_each_crtc(tmp, dev) { if (tmp->port == port) return 1 << index; index++; } return 0; } EXPORT_SYMBOL(drm_of_crtc_port_mask); /** * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port * @dev: DRM device * @port: encoder port to scan for endpoints * * Scan all endpoints attached to a port, locate their attached CRTCs, * and generate the DRM mask of CRTCs which may be attached to this * encoder. * * See https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/graph.yaml * for the bindings. */ uint32_t drm_of_find_possible_crtcs(struct drm_device *dev, struct device_node *port) { struct device_node *remote_port, *ep; uint32_t possible_crtcs = 0; for_each_endpoint_of_node(port, ep) { remote_port = of_graph_get_remote_port(ep); if (!remote_port) { of_node_put(ep); return 0; } possible_crtcs |= drm_of_crtc_port_mask(dev, remote_port); of_node_put(remote_port); } return possible_crtcs; } EXPORT_SYMBOL(drm_of_find_possible_crtcs); /** * drm_of_component_match_add - Add a component helper OF node match rule * @master: master device * @matchptr: component match pointer * @compare: compare function used for matching component * @node: of_node */ void drm_of_component_match_add(struct device *master, struct component_match **matchptr, int (*compare)(struct device *, void *), struct device_node *node) { of_node_get(node); component_match_add_release(master, matchptr, component_release_of, compare, node); } EXPORT_SYMBOL_GPL(drm_of_component_match_add); /** * drm_of_component_probe - Generic probe function for a component based master * @dev: master device containing the OF node * @compare_of: compare function used for matching components * @m_ops: component master ops to be used * * Parse the platform device OF node and bind all the components associated * with the master. Interface ports are added before the encoders in order to * satisfy their .bind requirements * * See https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/graph.yaml * for the bindings. * * Returns zero if successful, or one of the standard error codes if it fails. */ int drm_of_component_probe(struct device *dev, int (*compare_of)(struct device *, void *), const struct component_master_ops *m_ops) { struct device_node *ep, *port, *remote; struct component_match *match = NULL; int i; if (!dev->of_node) return -EINVAL; /* * Bind the crtc's ports first, so that drm_of_find_possible_crtcs() * called from encoder's .bind callbacks works as expected */ for (i = 0; ; i++) { port = of_parse_phandle(dev->of_node, "ports", i); if (!port) break; if (of_device_is_available(port->parent)) drm_of_component_match_add(dev, &match, compare_of, port); of_node_put(port); } if (i == 0) { dev_err(dev, "missing 'ports' property\n"); return -ENODEV; } if (!match) { dev_err(dev, "no available port\n"); return -ENODEV; } /* * For bound crtcs, bind the encoders attached to their remote endpoint */ for (i = 0; ; i++) { port = of_parse_phandle(dev->of_node, "ports", i); if (!port) break; if (!of_device_is_available(port->parent)) { of_node_put(port); continue; } for_each_child_of_node(port, ep) { remote = of_graph_get_remote_port_parent(ep); if (!remote || !of_device_is_available(remote)) { of_node_put(remote); continue; } else if (!of_device_is_available(remote->parent)) { dev_warn(dev, "parent device of %pOF is not available\n", remote); of_node_put(remote); continue; } drm_of_component_match_add(dev, &match, compare_of, remote); of_node_put(remote); } of_node_put(port); } return component_master_add_with_match(dev, m_ops, match); } EXPORT_SYMBOL(drm_of_component_probe); /* * drm_of_encoder_active_endpoint - return the active encoder endpoint * @node: device tree node containing encoder input ports * @encoder: drm_encoder * * Given an encoder device node and a drm_encoder with a connected crtc, * parse the encoder endpoint connecting to the crtc port. */ int drm_of_encoder_active_endpoint(struct device_node *node, struct drm_encoder *encoder, struct of_endpoint *endpoint) { struct device_node *ep; struct drm_crtc *crtc = encoder->crtc; struct device_node *port; int ret; if (!node || !crtc) return -EINVAL; for_each_endpoint_of_node(node, ep) { port = of_graph_get_remote_port(ep); of_node_put(port); if (port == crtc->port) { ret = of_graph_parse_endpoint(ep, endpoint); of_node_put(ep); return ret; } } return -EINVAL; } EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint); /** * drm_of_find_panel_or_bridge - return connected panel or bridge device * @np: device tree node containing encoder output ports * @port: port in the device tree node * @endpoint: endpoint in the device tree node * @panel: pointer to hold returned drm_panel * @bridge: pointer to hold returned drm_bridge * * Given a DT node's port and endpoint number, find the connected node and * return either the associated struct drm_panel or drm_bridge device. Either * @panel or @bridge must not be NULL. * * This function is deprecated and should not be used in new drivers. Use * devm_drm_of_get_bridge() instead. * * Returns zero if successful, or one of the standard error codes if it fails. */ int drm_of_find_panel_or_bridge(const struct device_node *np, int port, int endpoint, struct drm_panel **panel, struct drm_bridge **bridge) { int ret = -EPROBE_DEFER; struct device_node *remote; if (!panel && !bridge) return -EINVAL; if (panel) *panel = NULL; /* * of_graph_get_remote_node() produces a noisy error message if port * node isn't found and the absence of the port is a legit case here, * so at first we silently check whether graph presents in the * device-tree node. */ if (!of_graph_is_present(np)) return -ENODEV; remote = of_graph_get_remote_node(np, port, endpoint); if (!remote) return -ENODEV; if (panel) { *panel = of_drm_find_panel(remote); if (!IS_ERR(*panel)) ret = 0; else *panel = NULL; } if (bridge) { if (ret) { /* No panel found yet, check for a bridge next. */ *bridge = of_drm_find_bridge(remote); if (*bridge) ret = 0; } else { *bridge = NULL; } } of_node_put(remote); return ret; } EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge); enum drm_of_lvds_pixels { DRM_OF_LVDS_EVEN = BIT(0), DRM_OF_LVDS_ODD = BIT(1), }; static int drm_of_lvds_get_port_pixels_type(struct device_node *port_node) { bool even_pixels = of_property_read_bool(port_node, "dual-lvds-even-pixels"); bool odd_pixels = of_property_read_bool(port_node, "dual-lvds-odd-pixels"); return (even_pixels ? DRM_OF_LVDS_EVEN : 0) | (odd_pixels ? DRM_OF_LVDS_ODD : 0); } static int drm_of_lvds_get_remote_pixels_type( const struct device_node *port_node) { struct device_node *endpoint = NULL; int pixels_type = -EPIPE; for_each_child_of_node(port_node, endpoint) { struct device_node *remote_port; int current_pt; if (!of_node_name_eq(endpoint, "endpoint")) continue; remote_port = of_graph_get_remote_port(endpoint); if (!remote_port) { of_node_put(endpoint); return -EPIPE; } current_pt = drm_of_lvds_get_port_pixels_type(remote_port); of_node_put(remote_port); if (pixels_type < 0) pixels_type = current_pt; /* * Sanity check, ensure that all remote endpoints have the same * pixel type. We may lift this restriction later if we need to * support multiple sinks with different dual-link * configurations by passing the endpoints explicitly to * drm_of_lvds_get_dual_link_pixel_order(). */ if (!current_pt || pixels_type != current_pt) { of_node_put(endpoint); return -EINVAL; } } return pixels_type; } static int __drm_of_lvds_get_dual_link_pixel_order(int p1_pt, int p2_pt) { /* * A valid dual-lVDS bus is found when one port is marked with * "dual-lvds-even-pixels", and the other port is marked with * "dual-lvds-odd-pixels", bail out if the markers are not right. */ if (p1_pt + p2_pt != DRM_OF_LVDS_EVEN + DRM_OF_LVDS_ODD) return -EINVAL; return p1_pt == DRM_OF_LVDS_EVEN ? DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS : DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS; } /** * drm_of_lvds_get_dual_link_pixel_order - Get LVDS dual-link source pixel order * @port1: First DT port node of the Dual-link LVDS source * @port2: Second DT port node of the Dual-link LVDS source * * An LVDS dual-link connection is made of two links, with even pixels * transitting on one link, and odd pixels on the other link. This function * returns, for two ports of an LVDS dual-link source, which port shall transmit * the even and odd pixels, based on the requirements of the connected sink. * * The pixel order is determined from the dual-lvds-even-pixels and * dual-lvds-odd-pixels properties in the sink's DT port nodes. If those * properties are not present, or if their usage is not valid, this function * returns -EINVAL. * * If either port is not connected, this function returns -EPIPE. * * @port1 and @port2 are typically DT sibling nodes, but may have different * parents when, for instance, two separate LVDS encoders carry the even and odd * pixels. * * Return: * * DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS - @port1 carries even pixels and @port2 * carries odd pixels * * DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS - @port1 carries odd pixels and @port2 * carries even pixels * * -EINVAL - @port1 and @port2 are not connected to a dual-link LVDS sink, or * the sink configuration is invalid * * -EPIPE - when @port1 or @port2 are not connected */ int drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1, const struct device_node *port2) { int remote_p1_pt, remote_p2_pt; if (!port1 || !port2) return -EINVAL; remote_p1_pt = drm_of_lvds_get_remote_pixels_type(port1); if (remote_p1_pt < 0) return remote_p1_pt; remote_p2_pt = drm_of_lvds_get_remote_pixels_type(port2); if (remote_p2_pt < 0) return remote_p2_pt; return __drm_of_lvds_get_dual_link_pixel_order(remote_p1_pt, remote_p2_pt); } EXPORT_SYMBOL_GPL(drm_of_lvds_get_dual_link_pixel_order); /** * drm_of_lvds_get_dual_link_pixel_order_sink - Get LVDS dual-link sink pixel order * @port1: First DT port node of the Dual-link LVDS sink * @port2: Second DT port node of the Dual-link LVDS sink * * An LVDS dual-link connection is made of two links, with even pixels * transitting on one link, and odd pixels on the other link. This function * returns, for two ports of an LVDS dual-link sink, which port shall transmit * the even and odd pixels, based on the requirements of the sink. * * The pixel order is determined from the dual-lvds-even-pixels and * dual-lvds-odd-pixels properties in the sink's DT port nodes. If those * properties are not present, or if their usage is not valid, this function * returns -EINVAL. * * If either port is not connected, this function returns -EPIPE. * * @port1 and @port2 are typically DT sibling nodes, but may have different * parents when, for instance, two separate LVDS decoders receive the even and * odd pixels. * * Return: * * DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS - @port1 receives even pixels and @port2 * receives odd pixels * * DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS - @port1 receives odd pixels and @port2 * receives even pixels * * -EINVAL - @port1 or @port2 are NULL * * -EPIPE - when @port1 or @port2 are not connected */ int drm_of_lvds_get_dual_link_pixel_order_sink(struct device_node *port1, struct device_node *port2) { int sink_p1_pt, sink_p2_pt; if (!port1 || !port2) return -EINVAL; sink_p1_pt = drm_of_lvds_get_port_pixels_type(port1); if (!sink_p1_pt) return -EPIPE; sink_p2_pt = drm_of_lvds_get_port_pixels_type(port2); if (!sink_p2_pt) return -EPIPE; return __drm_of_lvds_get_dual_link_pixel_order(sink_p1_pt, sink_p2_pt); } EXPORT_SYMBOL_GPL(drm_of_lvds_get_dual_link_pixel_order_sink); /** * drm_of_lvds_get_data_mapping - Get LVDS data mapping * @port: DT port node of the LVDS source or sink * * Convert DT "data-mapping" property string value into media bus format value. * * Return: * * MEDIA_BUS_FMT_RGB666_1X7X3_SPWG - data-mapping is "jeida-18" * * MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA - data-mapping is "jeida-24" * * MEDIA_BUS_FMT_RGB101010_1X7X5_JEIDA - data-mapping is "jeida-30" * * MEDIA_BUS_FMT_RGB888_1X7X4_SPWG - data-mapping is "vesa-24" * * MEDIA_BUS_FMT_RGB101010_1X7X5_SPWG - data-mapping is "vesa-30" * * -EINVAL - the "data-mapping" property is unsupported * * -ENODEV - the "data-mapping" property is missing */ int drm_of_lvds_get_data_mapping(const struct device_node *port) { const char *mapping; int ret; ret = of_property_read_string(port, "data-mapping", &mapping); if (ret < 0) return -ENODEV; if (!strcmp(mapping, "jeida-18")) return MEDIA_BUS_FMT_RGB666_1X7X3_SPWG; if (!strcmp(mapping, "jeida-24")) return MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA; if (!strcmp(mapping, "jeida-30")) return MEDIA_BUS_FMT_RGB101010_1X7X5_JEIDA; if (!strcmp(mapping, "vesa-24")) return MEDIA_BUS_FMT_RGB888_1X7X4_SPWG; if (!strcmp(mapping, "vesa-30")) return MEDIA_BUS_FMT_RGB101010_1X7X5_SPWG; return -EINVAL; } EXPORT_SYMBOL_GPL(drm_of_lvds_get_data_mapping); /** * drm_of_get_data_lanes_count - Get DSI/(e)DP data lane count * @endpoint: DT endpoint node of the DSI/(e)DP source or sink * @min: minimum supported number of data lanes * @max: maximum supported number of data lanes * * Count DT "data-lanes" property elements and check for validity. * * Return: * * min..max - positive integer count of "data-lanes" elements * * -ve - the "data-lanes" property is missing or invalid * * -EINVAL - the "data-lanes" property is unsupported */ int drm_of_get_data_lanes_count(const struct device_node *endpoint, const unsigned int min, const unsigned int max) { int ret; ret = of_property_count_u32_elems(endpoint, "data-lanes"); if (ret < 0) return ret; if (ret < min || ret > max) return -EINVAL; return ret; } EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count); /** * drm_of_get_data_lanes_count_ep - Get DSI/(e)DP data lane count by endpoint * @port: DT port node of the DSI/(e)DP source or sink * @port_reg: identifier (value of reg property) of the parent port node * @reg: identifier (value of reg property) of the endpoint node * @min: minimum supported number of data lanes * @max: maximum supported number of data lanes * * Count DT "data-lanes" property elements and check for validity. * This variant uses endpoint specifier. * * Return: * * min..max - positive integer count of "data-lanes" elements * * -EINVAL - the "data-mapping" property is unsupported * * -ENODEV - the "data-mapping" property is missing */ int drm_of_get_data_lanes_count_ep(const struct device_node *port, int port_reg, int reg, const unsigned int min, const unsigned int max) { struct device_node *endpoint; int ret; endpoint = of_graph_get_endpoint_by_regs(port, port_reg, reg); ret = drm_of_get_data_lanes_count(endpoint, min, max); of_node_put(endpoint); return ret; } EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count_ep); #if IS_ENABLED(CONFIG_DRM_MIPI_DSI) /** * drm_of_get_dsi_bus - find the DSI bus for a given device * @dev: parent device of display (SPI, I2C) * * Gets parent DSI bus for a DSI device controlled through a bus other * than MIPI-DCS (SPI, I2C, etc.) using the Device Tree. * * This function assumes that the device's port@0 is the DSI input. * * Returns pointer to mipi_dsi_host if successful, -EINVAL if the * request is unsupported, -EPROBE_DEFER if the DSI host is found but * not available, or -ENODEV otherwise. */ struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev) { struct mipi_dsi_host *dsi_host; struct device_node *endpoint, *dsi_host_node; /* * Get first endpoint child from device. */ endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1); if (!endpoint) return ERR_PTR(-ENODEV); /* * Follow the first endpoint to get the DSI host node and then * release the endpoint since we no longer need it. */ dsi_host_node = of_graph_get_remote_port_parent(endpoint); of_node_put(endpoint); if (!dsi_host_node) return ERR_PTR(-ENODEV); /* * Get the DSI host from the DSI host node. If we get an error * or the return is null assume we're not ready to probe just * yet. Release the DSI host node since we're done with it. */ dsi_host = of_find_mipi_dsi_host_by_node(dsi_host_node); of_node_put(dsi_host_node); if (IS_ERR_OR_NULL(dsi_host)) return ERR_PTR(-EPROBE_DEFER); return dsi_host; } EXPORT_SYMBOL_GPL(drm_of_get_dsi_bus); #endif /* CONFIG_DRM_MIPI_DSI */
