177 lines
4.9 KiB
C
177 lines
4.9 KiB
C
/*
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* Copyright (C) 2013, NVIDIA Corporation. All rights reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sub license,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the
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* next paragraph) shall be included in all copies or substantial portions
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* of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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* DEALINGS IN THE SOFTWARE.
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*/
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#include <linux/err.h>
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#include <linux/module.h>
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#include <drm/drm_crtc.h>
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#include <drm/drm_panel.h>
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static DEFINE_MUTEX(panel_lock);
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static LIST_HEAD(panel_list);
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/**
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* DOC: drm panel
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*
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* The DRM panel helpers allow drivers to register panel objects with a
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* central registry and provide functions to retrieve those panels in display
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* drivers.
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*/
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/**
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* drm_panel_init - initialize a panel
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* @panel: DRM panel
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*
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* Sets up internal fields of the panel so that it can subsequently be added
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* to the registry.
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*/
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void drm_panel_init(struct drm_panel *panel)
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{
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INIT_LIST_HEAD(&panel->list);
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}
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EXPORT_SYMBOL(drm_panel_init);
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/**
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* drm_panel_add - add a panel to the global registry
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* @panel: panel to add
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*
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* Add a panel to the global registry so that it can be looked up by display
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* drivers.
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*
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* Return: 0 on success or a negative error code on failure.
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*/
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int drm_panel_add(struct drm_panel *panel)
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{
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mutex_lock(&panel_lock);
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list_add_tail(&panel->list, &panel_list);
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mutex_unlock(&panel_lock);
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return 0;
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}
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EXPORT_SYMBOL(drm_panel_add);
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/**
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* drm_panel_remove - remove a panel from the global registry
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* @panel: DRM panel
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*
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* Removes a panel from the global registry.
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*/
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void drm_panel_remove(struct drm_panel *panel)
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{
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mutex_lock(&panel_lock);
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list_del_init(&panel->list);
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mutex_unlock(&panel_lock);
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}
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EXPORT_SYMBOL(drm_panel_remove);
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/**
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* drm_panel_attach - attach a panel to a connector
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* @panel: DRM panel
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* @connector: DRM connector
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*
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* After obtaining a pointer to a DRM panel a display driver calls this
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* function to attach a panel to a connector.
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*
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* An error is returned if the panel is already attached to another connector.
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*
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* When unloading, the driver should detach from the panel by calling
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* drm_panel_detach().
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*
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* Return: 0 on success or a negative error code on failure.
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*/
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int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector)
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{
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if (panel->connector)
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return -EBUSY;
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panel->connector = connector;
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panel->drm = connector->dev;
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return 0;
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}
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EXPORT_SYMBOL(drm_panel_attach);
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/**
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* drm_panel_detach - detach a panel from a connector
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* @panel: DRM panel
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*
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* Detaches a panel from the connector it is attached to. If a panel is not
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* attached to any connector this is effectively a no-op.
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*
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* This function should not be called by the panel device itself. It
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* is only for the drm device that called drm_panel_attach().
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*
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* Return: 0 on success or a negative error code on failure.
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*/
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int drm_panel_detach(struct drm_panel *panel)
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{
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panel->connector = NULL;
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panel->drm = NULL;
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return 0;
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}
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EXPORT_SYMBOL(drm_panel_detach);
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#ifdef CONFIG_OF
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/**
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* of_drm_find_panel - look up a panel using a device tree node
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* @np: device tree node of the panel
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*
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* Searches the set of registered panels for one that matches the given device
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* tree node. If a matching panel is found, return a pointer to it.
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*
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* Return: A pointer to the panel registered for the specified device tree
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* node or an ERR_PTR() if no panel matching the device tree node can be found.
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*
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* Possible error codes returned by this function:
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*
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* - EPROBE_DEFER: the panel device has not been probed yet, and the caller
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* should retry later
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* - ENODEV: the device is not available (status != "okay" or "ok")
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*/
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struct drm_panel *of_drm_find_panel(const struct device_node *np)
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{
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struct drm_panel *panel;
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if (!of_device_is_available(np))
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return ERR_PTR(-ENODEV);
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mutex_lock(&panel_lock);
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list_for_each_entry(panel, &panel_list, list) {
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if (panel->dev->of_node == np) {
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mutex_unlock(&panel_lock);
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return panel;
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}
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}
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mutex_unlock(&panel_lock);
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return ERR_PTR(-EPROBE_DEFER);
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}
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EXPORT_SYMBOL(of_drm_find_panel);
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#endif
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MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
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MODULE_DESCRIPTION("DRM panel infrastructure");
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MODULE_LICENSE("GPL and additional rights");
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