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Diffstat (limited to 'drivers/gpu/drm/drm_of.c')
-rw-r--r--drivers/gpu/drm/drm_of.c495
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);