Quelle  panel.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 * Copyright (C) 2017 Broadcom
 */

#include <linux/debugfs.h>
#include <linux/export.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_connector.h>
#include <drm/drm_encoder.h>
#include <drm/drm_managed.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

struct panel_bridge {
 struct drm_bridge bridge;
 struct drm_connector connector;
 struct drm_panel *panel;
 u32 connector_type;
};

static inline struct panel_bridge *
drm_bridge_to_panel_bridge(struct drm_bridge *bridge)
{
 return container_of(bridge, struct panel_bridge, bridge);
}

static inline struct panel_bridge *
drm_connector_to_panel_bridge(struct drm_connector *connector)
{
 return container_of(connector, struct panel_bridge, connector);
}

static int panel_bridge_connector_get_modes(struct drm_connector *connector)
{
 struct panel_bridge *panel_bridge =
  drm_connector_to_panel_bridge(connector);

 return drm_panel_get_modes(panel_bridge->panel, connector);
}

static const struct drm_connector_helper_funcs
panel_bridge_connector_helper_funcs = {
 .get_modes = panel_bridge_connector_get_modes,
};

static const struct drm_connector_funcs panel_bridge_connector_funcs = {
 .reset = drm_atomic_helper_connector_reset,
 .fill_modes = drm_helper_probe_single_connector_modes,
 .destroy = drm_connector_cleanup,
 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static int panel_bridge_attach(struct drm_bridge *bridge,
          struct drm_encoder *encoder,
          enum drm_bridge_attach_flags flags)
{
 struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
 struct drm_connector *connector = &panel_bridge->connector;
 int ret;

 if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
  return 0;

 drm_connector_helper_add(connector,
     &panel_bridge_connector_helper_funcs);

 ret = drm_connector_init(bridge->dev, connector,
     &panel_bridge_connector_funcs,
     panel_bridge->connector_type);
 if (ret) {
  DRM_ERROR("Failed to initialize connector\n");
  return ret;
 }

 drm_panel_bridge_set_orientation(connector, bridge);

 drm_connector_attach_encoder(&panel_bridge->connector,
       encoder);

 if (bridge->dev->registered) {
  if (connector->funcs->reset)
   connector->funcs->reset(connector);
  drm_connector_register(connector);
 }

 return 0;
}

static void panel_bridge_detach(struct drm_bridge *bridge)
{
 struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
 struct drm_connector *connector = &panel_bridge->connector;

 /*
 * Cleanup the connector if we know it was initialized.
 *
 * FIXME: This wouldn't be needed if the panel_bridge structure was
 * allocated with drmm_kzalloc(). This might be tricky since the
 * drm_device pointer can only be retrieved when the bridge is attached.
 */
 if (connector->dev)
  drm_connector_cleanup(connector);
}

static void panel_bridge_atomic_pre_enable(struct drm_bridge *bridge,
        struct drm_atomic_state *atomic_state)
{
 struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
 struct drm_encoder *encoder = bridge->encoder;
 struct drm_crtc *crtc;
 struct drm_crtc_state *old_crtc_state;

 crtc = drm_atomic_get_new_crtc_for_encoder(atomic_state, encoder);
 if (!crtc)
  return;

 old_crtc_state = drm_atomic_get_old_crtc_state(atomic_state, crtc);
 if (old_crtc_state && old_crtc_state->self_refresh_active)
  return;

 drm_panel_prepare(panel_bridge->panel);
}

static void panel_bridge_atomic_enable(struct drm_bridge *bridge,
           struct drm_atomic_state *atomic_state)
{
 struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
 struct drm_encoder *encoder = bridge->encoder;
 struct drm_crtc *crtc;
 struct drm_crtc_state *old_crtc_state;

 crtc = drm_atomic_get_new_crtc_for_encoder(atomic_state, encoder);
 if (!crtc)
  return;

 old_crtc_state = drm_atomic_get_old_crtc_state(atomic_state, crtc);
 if (old_crtc_state && old_crtc_state->self_refresh_active)
  return;

 drm_panel_enable(panel_bridge->panel);
}

static void panel_bridge_atomic_disable(struct drm_bridge *bridge,
     struct drm_atomic_state *atomic_state)
{
 struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
 struct drm_encoder *encoder = bridge->encoder;
 struct drm_crtc *crtc;
 struct drm_crtc_state *new_crtc_state;

 crtc = drm_atomic_get_old_crtc_for_encoder(atomic_state, encoder);
 if (!crtc)
  return;

 new_crtc_state = drm_atomic_get_new_crtc_state(atomic_state, crtc);
 if (new_crtc_state && new_crtc_state->self_refresh_active)
  return;

 drm_panel_disable(panel_bridge->panel);
}

static void panel_bridge_atomic_post_disable(struct drm_bridge *bridge,
          struct drm_atomic_state *atomic_state)
{
 struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
 struct drm_encoder *encoder = bridge->encoder;
 struct drm_crtc *crtc;
 struct drm_crtc_state *new_crtc_state;

 crtc = drm_atomic_get_old_crtc_for_encoder(atomic_state, encoder);
 if (!crtc)
  return;

 new_crtc_state = drm_atomic_get_new_crtc_state(atomic_state, crtc);
 if (new_crtc_state && new_crtc_state->self_refresh_active)
  return;

 drm_panel_unprepare(panel_bridge->panel);
}

static int panel_bridge_get_modes(struct drm_bridge *bridge,
      struct drm_connector *connector)
{
 struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);

 return drm_panel_get_modes(panel_bridge->panel, connector);
}

static void panel_bridge_debugfs_init(struct drm_bridge *bridge,
          struct dentry *root)
{
 struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
 struct drm_panel *panel = panel_bridge->panel;

 root = debugfs_create_dir("panel", root);
 if (panel->funcs->debugfs_init)
  panel->funcs->debugfs_init(panel, root);
}

static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
 .attach = panel_bridge_attach,
 .detach = panel_bridge_detach,
 .atomic_pre_enable = panel_bridge_atomic_pre_enable,
 .atomic_enable = panel_bridge_atomic_enable,
 .atomic_disable = panel_bridge_atomic_disable,
 .atomic_post_disable = panel_bridge_atomic_post_disable,
 .get_modes = panel_bridge_get_modes,
 .atomic_reset = drm_atomic_helper_bridge_reset,
 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
 .atomic_get_input_bus_fmts = drm_atomic_helper_bridge_propagate_bus_fmt,
 .debugfs_init = panel_bridge_debugfs_init,
};

/**
 * drm_bridge_is_panel - Checks if a drm_bridge is a panel_bridge.
 *
 * @bridge: The drm_bridge to be checked.
 *
 * Returns true if the bridge is a panel bridge, or false otherwise.
 */
bool drm_bridge_is_panel(const struct drm_bridge *bridge)
{
 return bridge->funcs == &panel_bridge_bridge_funcs;
}
EXPORT_SYMBOL(drm_bridge_is_panel);

/**
 * drm_panel_bridge_add - Creates a &drm_bridge and &drm_connector that
 * just calls the appropriate functions from &drm_panel.
 *
 * @panel: The drm_panel being wrapped.  Must be non-NULL.
 *
 * For drivers converting from directly using drm_panel: The expected
 * usage pattern is that during either encoder module probe or DSI
 * host attach, a drm_panel will be looked up through
 * drm_of_find_panel_or_bridge().  drm_panel_bridge_add() is used to
 * wrap that panel in the new bridge, and the result can then be
 * passed to drm_bridge_attach().  The drm_panel_prepare() and related
 * functions can be dropped from the encoder driver (they're now
 * called by the KMS helpers before calling into the encoder), along
 * with connector creation.  When done with the bridge (after
 * drm_mode_config_cleanup() if the bridge has already been attached), then
 * drm_panel_bridge_remove() to free it.
 *
 * The connector type is set to @panel->connector_type, which must be set to a
 * known type. Calling this function with a panel whose connector type is
 * DRM_MODE_CONNECTOR_Unknown will return ERR_PTR(-EINVAL).
 *
 * See devm_drm_panel_bridge_add() for an automatically managed version of this
 * function.
 */
struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel)
{
 if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
  return ERR_PTR(-EINVAL);

 return drm_panel_bridge_add_typed(panel, panel->connector_type);
}
EXPORT_SYMBOL(drm_panel_bridge_add);

/**
 * drm_panel_bridge_add_typed - Creates a &drm_bridge and &drm_connector with
 * an explicit connector type.
 * @panel: The drm_panel being wrapped.  Must be non-NULL.
 * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
 *
 * This is just like drm_panel_bridge_add(), but forces the connector type to
 * @connector_type instead of infering it from the panel.
 *
 * This function is deprecated and should not be used in new drivers. Use
 * drm_panel_bridge_add() instead, and fix panel drivers as necessary if they
 * don't report a connector type.
 */
struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
           u32 connector_type)
{
 struct panel_bridge *panel_bridge;

 if (!panel)
  return ERR_PTR(-EINVAL);

 panel_bridge = devm_drm_bridge_alloc(panel->dev, struct panel_bridge, bridge,
          &panel_bridge_bridge_funcs);
 if (IS_ERR(panel_bridge))
  return (void *)panel_bridge;

 panel_bridge->connector_type = connector_type;
 panel_bridge->panel = panel;

 panel_bridge->bridge.of_node = panel->dev->of_node;
 panel_bridge->bridge.ops = DRM_BRIDGE_OP_MODES;
 panel_bridge->bridge.type = connector_type;
 panel_bridge->bridge.pre_enable_prev_first = panel->prepare_prev_first;

 drm_bridge_add(&panel_bridge->bridge);

 return &panel_bridge->bridge;
}
EXPORT_SYMBOL(drm_panel_bridge_add_typed);

/**
 * drm_panel_bridge_remove - Unregisters and frees a drm_bridge
 * created by drm_panel_bridge_add().
 *
 * @bridge: The drm_bridge being freed.
 */
void drm_panel_bridge_remove(struct drm_bridge *bridge)
{
 struct panel_bridge *panel_bridge;

 if (!bridge)
  return;

 if (!drm_bridge_is_panel(bridge)) {
  drm_warn(bridge->dev, "%s: called on non-panel bridge!\n", __func__);
  return;
 }

 panel_bridge = drm_bridge_to_panel_bridge(bridge);

 drm_bridge_remove(bridge);
 /* TODO remove this after reworking panel_bridge lifetime */
 devm_drm_put_bridge(panel_bridge->panel->dev, bridge);
}
EXPORT_SYMBOL(drm_panel_bridge_remove);

/**
 * drm_panel_bridge_set_orientation - Set the connector's panel orientation
 * from the bridge that can be transformed to panel bridge.
 *
 * @connector: The connector to be set panel orientation.
 * @bridge: The drm_bridge to be transformed to panel bridge.
 *
 * Returns 0 on success, negative errno on failure.
 */
int drm_panel_bridge_set_orientation(struct drm_connector *connector,
         struct drm_bridge *bridge)
{
 struct panel_bridge *panel_bridge;

 panel_bridge = drm_bridge_to_panel_bridge(bridge);

 return drm_connector_set_orientation_from_panel(connector,
       panel_bridge->panel);
}
EXPORT_SYMBOL(drm_panel_bridge_set_orientation);

static void devm_drm_panel_bridge_release(struct device *dev, void *res)
{
 struct drm_bridge *bridge = *(struct drm_bridge **)res;

 if (!bridge)
  return;

 drm_bridge_remove(bridge);
}

/**
 * devm_drm_panel_bridge_add - Creates a managed &drm_bridge and &drm_connector
 * that just calls the appropriate functions from &drm_panel.
 * @dev: device to tie the bridge lifetime to
 * @panel: The drm_panel being wrapped.  Must be non-NULL.
 *
 * This is the managed version of drm_panel_bridge_add() which automatically
 * calls drm_panel_bridge_remove() when @dev is unbound.
 */
struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
          struct drm_panel *panel)
{
 if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
  return ERR_PTR(-EINVAL);

 return devm_drm_panel_bridge_add_typed(dev, panel,
            panel->connector_type);
}
EXPORT_SYMBOL(devm_drm_panel_bridge_add);

/**
 * devm_drm_panel_bridge_add_typed - Creates a managed &drm_bridge and
 * &drm_connector with an explicit connector type.
 * @dev: device to tie the bridge lifetime to
 * @panel: The drm_panel being wrapped.  Must be non-NULL.
 * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
 *
 * This is just like devm_drm_panel_bridge_add(), but forces the connector type
 * to @connector_type instead of infering it from the panel.
 *
 * This function is deprecated and should not be used in new drivers. Use
 * devm_drm_panel_bridge_add() instead, and fix panel drivers as necessary if
 * they don't report a connector type.
 */
struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
         struct drm_panel *panel,
         u32 connector_type)
{
 struct drm_bridge **ptr, *bridge;

 ptr = devres_alloc(devm_drm_panel_bridge_release, sizeof(*ptr),
      GFP_KERNEL);
 if (!ptr)
  return ERR_PTR(-ENOMEM);

 bridge = drm_panel_bridge_add_typed(panel, connector_type);
 if (IS_ERR(bridge)) {
  devres_free(ptr);
  return bridge;
 }

 *ptr = bridge;
 devres_add(dev, ptr);

 return bridge;
}
EXPORT_SYMBOL(devm_drm_panel_bridge_add_typed);

static void drmm_drm_panel_bridge_release(struct drm_device *drm, void *ptr)
{
 struct drm_bridge *bridge = ptr;

 drm_panel_bridge_remove(bridge);
}

/**
 * drmm_panel_bridge_add - Creates a DRM-managed &drm_bridge and
 *                         &drm_connector that just calls the
 *                         appropriate functions from &drm_panel.
 *
 * @drm: DRM device to tie the bridge lifetime to
 * @panel: The drm_panel being wrapped.  Must be non-NULL.
 *
 * This is the DRM-managed version of drm_panel_bridge_add() which
 * automatically calls drm_panel_bridge_remove() when @dev is cleaned
 * up.
 */
struct drm_bridge *drmm_panel_bridge_add(struct drm_device *drm,
      struct drm_panel *panel)
{
 struct drm_bridge *bridge;
 int ret;

 bridge = drm_panel_bridge_add_typed(panel, panel->connector_type);
 if (IS_ERR(bridge))
  return bridge;

 ret = drmm_add_action_or_reset(drm, drmm_drm_panel_bridge_release,
           bridge);
 if (ret)
  return ERR_PTR(ret);

 return bridge;
}
EXPORT_SYMBOL(drmm_panel_bridge_add);

/**
 * drm_panel_bridge_connector - return the connector for the panel bridge
 * @bridge: The drm_bridge.
 *
 * drm_panel_bridge creates the connector.
 * This function gives external access to the connector.
 *
 * Returns: Pointer to drm_connector
 */
struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge)
{
 struct panel_bridge *panel_bridge;

 panel_bridge = drm_bridge_to_panel_bridge(bridge);

 return &panel_bridge->connector;
}
EXPORT_SYMBOL(drm_panel_bridge_connector);

#ifdef CONFIG_OF
/**
 * devm_drm_of_get_bridge - Return next bridge in the chain
 * @dev: device to tie the bridge lifetime to
 * @np: device tree node containing encoder output ports
 * @port: port in the device tree node
 * @endpoint: endpoint in the device tree node
 *
 * Given a DT node's port and endpoint number, finds the connected node
 * and returns the associated bridge if any, or creates and returns a
 * drm panel bridge instance if a panel is connected.
 *
 * Returns a pointer to the bridge if successful, or an error pointer
 * otherwise.
 */
struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
       struct device_node *np,
       u32 port, u32 endpoint)
{
 struct drm_bridge *bridge;
 struct drm_panel *panel;
 int ret;

 ret = drm_of_find_panel_or_bridge(np, port, endpoint,
       &panel, &bridge);
 if (ret)
  return ERR_PTR(ret);

 if (panel)
  bridge = devm_drm_panel_bridge_add(dev, panel);

 return bridge;
}
EXPORT_SYMBOL(devm_drm_of_get_bridge);

/**
 * drmm_of_get_bridge - Return next bridge in the chain
 * @drm: device to tie the bridge lifetime to
 * @np: device tree node containing encoder output ports
 * @port: port in the device tree node
 * @endpoint: endpoint in the device tree node
 *
 * Given a DT node's port and endpoint number, finds the connected node
 * and returns the associated bridge if any, or creates and returns a
 * drm panel bridge instance if a panel is connected.
 *
 * Returns a drmm managed pointer to the bridge if successful, or an error
 * pointer otherwise.
 */
struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
          struct device_node *np,
          u32 port, u32 endpoint)
{
 struct drm_bridge *bridge;
 struct drm_panel *panel;
 int ret;

 ret = drm_of_find_panel_or_bridge(np, port, endpoint,
       &panel, &bridge);
 if (ret)
  return ERR_PTR(ret);

 if (panel)
  bridge = drmm_panel_bridge_add(drm, panel);

 return bridge;
}
EXPORT_SYMBOL(drmm_of_get_bridge);

#endif