diff options
Diffstat (limited to 'drivers/gpu/drm/drm_of.c')
| -rw-r--r-- | drivers/gpu/drm/drm_of.c | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c new file mode 100644 index 000000000..7bbcb999b --- /dev/null +++ b/drivers/gpu/drm/drm_of.c @@ -0,0 +1,495 @@ +// 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_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 Documentation/devicetree/bindings/graph.txt 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 Documentation/devicetree/bindings/graph.txt 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; + } + + /* No panel found yet, check for a bridge next. */ + if (bridge) { + if (ret) { + *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; +} + +/** + * drm_of_lvds_get_dual_link_pixel_order - Get LVDS dual-link 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; + + /* + * A valid dual-lVDS bus is found when one remote port is marked with + * "dual-lvds-even-pixels", and the other remote port is marked with + * "dual-lvds-odd-pixels", bail out if the markers are not right. + */ + if (remote_p1_pt + remote_p2_pt != DRM_OF_LVDS_EVEN + DRM_OF_LVDS_ODD) + return -EINVAL; + + return remote_p1_pt == DRM_OF_LVDS_EVEN ? + DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS : + DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS; +} +EXPORT_SYMBOL_GPL(drm_of_lvds_get_dual_link_pixel_order); + +/** + * 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_RGB888_1X7X4_SPWG - data-mapping is "vesa-24" + * * -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, "vesa-24")) + return MEDIA_BUS_FMT_RGB888_1X7X4_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); |