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      1 /*
      2 * Copyright (c) 2014 - 2016, The Linux Foundation. All rights reserved.
      3 *
      4 * Redistribution and use in source and binary forms, with or without
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      8 *       notice, this list of conditions and the following disclaimer.
      9 *     * Redistributions in binary form must reproduce the above
     10 *       copyright notice, this list of conditions and the following
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     12 *       with the distribution.
     13 *     * Neither the name of The Linux Foundation nor the names of its
     14 *       contributors may be used to endorse or promote products derived
     15 *       from this software without specific prior written permission.
     16 *
     17 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
     18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
     20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
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     23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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     25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
     26 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
     27 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28 */
     29 
     30 /*! @file core_interface.h
     31   @brief Interface file for core of the display subsystem.
     32 
     33   @details Display core is primarily used for loading and unloading different display device
     34   components viz primary, external and virtual. Display core is a statically linked library which
     35   runs in caller's process context.
     36 */
     37 #ifndef __CORE_INTERFACE_H__
     38 #define __CORE_INTERFACE_H__
     39 
     40 #include <stdint.h>
     41 
     42 #include "display_interface.h"
     43 #include "sdm_types.h"
     44 #include "buffer_allocator.h"
     45 #include "buffer_sync_handler.h"
     46 
     47 /*! @brief Display manager interface version.
     48 
     49   @details Display manager interfaces are version tagged to maintain backward compatibility. This
     50   version is supplied as a default argument during display core initialization.
     51 
     52   Client may use an older version of interfaces and link to a higher version of display manager
     53   library, but vice versa is not allowed.
     54 
     55   A 32-bit client must use 32-bit display core library and a 64-bit client must use 64-bit display
     56   core library.
     57 
     58   Display manager interfaces follow default data structures alignment. Client must not override the
     59   default padding rules while using these interfaces.
     60 
     61   @warning It is assumed that client upgrades or downgrades display core interface all at once
     62   and recompile all binaries which use these interfaces. Mix and match of these interfaces can
     63   lead to unpredictable behaviour.
     64 
     65   @sa CoreInterface::CreateCore
     66 */
     67 #define SDM_REVISION_MAJOR (1)
     68 #define SDM_REVISION_MINOR (0)
     69 
     70 #define SDM_VERSION_TAG ((uint32_t) ((SDM_REVISION_MAJOR << 24) | (SDM_REVISION_MINOR << 16) | \
     71                                     (sizeof(SDMCompatibility) << 8) | sizeof(int *)))
     72 
     73 namespace sdm {
     74 
     75 /*! @brief Forward declaration for debug handler.
     76 */
     77 class DebugHandler;
     78 
     79 /*! @brief This enum represents max bandwidth limit mode.
     80 
     81   @sa DisplayInterface::SetMaxBandwidthMode
     82 */
     83 enum HWBwModes {
     84   kBwDefault,      //!< Default state. No change in device bandwidth limit.
     85   kBwCamera,       //!< Camera is on. Bandwidth limit should be reduced accordingly.
     86   kBwVFlip,        //!< VFlip is required. Reduce bandwidth limit accordingly.
     87   kBwHFlip,        //!< HFlip is required.  Reduce bandwidth limit accordingly.
     88   kBwModeMax,      //!< Limiter for maximum available bandwidth modes.
     89 };
     90 
     91 
     92 /*! @brief Information on hardware for the first display
     93 
     94   @details This structure returns the display type of the first display on the device
     95   (internal display or HDMI etc) and whether it is currently connected,
     96 
     97 */
     98 struct HWDisplayInterfaceInfo {
     99   DisplayType type;
    100   bool is_connected;
    101 };
    102 
    103 /*! @brief Display core interface.
    104 
    105   @details This class defines display core interfaces. It contains methods which client shall use
    106   to create/destroy different display devices. This interface is created during display core
    107   CreateCore() and remains valid until DestroyCore().
    108 
    109   @sa CoreInterface::CreateCore
    110   @sa CoreInterface::DestroyCore
    111 */
    112 class CoreInterface {
    113  public:
    114   /*! @brief Method to create and get handle to display core interface.
    115 
    116     @details This method is the entry point into the display core. Client can create and operate on
    117     different display devices only through a valid interface handle obtained using this method. An
    118     object of display core is created and handle to this object is returned via output parameter.
    119     This interface shall be called only once.
    120 
    121     @param[in] debug_handler \link DebugHandler \endlink
    122     @param[in] buffer_allocator \link BufferAllocator \endlink
    123     @param[in] buffer_sync_handler \link BufferSyncHandler \endlink
    124     @param[out] interface \link CoreInterface \endlink
    125     @param[in] version \link SDM_VERSION_TAG \endlink. Client must not override this argument.
    126 
    127     @return \link DisplayError \endlink
    128 
    129     @sa DestroyCore
    130   */
    131   static DisplayError CreateCore(DebugHandler *debug_handler, BufferAllocator *buffer_allocator,
    132                                  BufferSyncHandler *buffer_sync_handler, CoreInterface **interface,
    133                                  uint32_t version = SDM_VERSION_TAG);
    134 
    135   /*! @brief Method to release handle to display core interface.
    136 
    137     @details The object of corresponding display core is destroyed when this method is invoked.
    138     Client must explicitly destroy all created display device objects associated with this handle
    139     before invoking this method.
    140 
    141     @param[in] interface \link CoreInterface \endlink
    142 
    143     @return \link DisplayError \endlink
    144 
    145     @sa CreateCore
    146   */
    147   static DisplayError DestroyCore();
    148 
    149   /*! @brief Method to create a display device for a given type.
    150 
    151     @details Client shall use this method to create each of the connected display type. A handle to
    152     interface associated with this object is returned via output parameter which can be used to
    153     interact further with the display device.
    154 
    155     @param[in] type \link DisplayType \endlink
    156     @param[in] event_handler \link DisplayEventHandler \endlink
    157     @param[out] interface \link DisplayInterface \endlink
    158 
    159     @return \link DisplayError \endlink
    160 
    161     @sa DestroyDisplay
    162   */
    163   virtual DisplayError CreateDisplay(DisplayType type, DisplayEventHandler *event_handler,
    164                                      DisplayInterface **interface) = 0;
    165 
    166   /*! @brief Method to destroy a display device.
    167 
    168     @details Client shall use this method to destroy each of the created display device objects.
    169 
    170     @param[in] interface \link DisplayInterface \endlink
    171 
    172     @return \link DisplayError \endlink
    173 
    174     @sa CreateDisplay
    175   */
    176   virtual DisplayError DestroyDisplay(DisplayInterface *interface) = 0;
    177 
    178   /*! @brief Method to update the bandwidth limit as per given mode.
    179 
    180     @param[in] mode indicate the mode or use case
    181 
    182     @return \link DisplayError \endlink
    183 
    184    */
    185     virtual DisplayError SetMaxBandwidthMode(HWBwModes mode) = 0;
    186 
    187   /*! @brief Method to get characteristics of the first display.
    188 
    189     @details Client shall use this method to determine if the first display is HDMI, and whether
    190     it is currently connected.
    191 
    192     @param[in] hw_disp_info structure that this method will fill up with info.
    193 
    194     @return \link DisplayError \endlink
    195 
    196    */
    197     virtual DisplayError GetFirstDisplayInterfaceType(HWDisplayInterfaceInfo *hw_disp_info) = 0;
    198 
    199 
    200  protected:
    201   virtual ~CoreInterface() { }
    202 };
    203 
    204 }  // namespace sdm
    205 
    206 #endif  // __CORE_INTERFACE_H__
    207 
    208