0,0 → 1,333 |
/* |
* Copyright (c) 2014 Samsung Electronics Co., Ltd |
* |
* Permission is hereby granted, free of charge, to any person obtaining a |
* copy of this software and associated documentation files (the "Software"), |
* to deal in the Software without restriction, including without limitation |
* the rights to use, copy, modify, merge, publish, distribute, sub license, |
* and/or sell copies of the Software, and to permit persons to whom the |
* Software is furnished to do so, subject to the following conditions: |
* |
* The above copyright notice and this permission notice (including the |
* next paragraph) shall be included in all copies or substantial portions |
* of the Software. |
* |
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
* DEALINGS IN THE SOFTWARE. |
*/ |
|
#include <linux/err.h> |
#include <linux/module.h> |
|
#include <drm/drm_crtc.h> |
|
#include "drm/drmP.h" |
|
/** |
* DOC: overview |
* |
* drm_bridge represents a device that hangs on to an encoder. These are handy |
* when a regular drm_encoder entity isn't enough to represent the entire |
* encoder chain. |
* |
* A bridge is always associated to a single drm_encoder at a time, but can be |
* either connected to it directly, or through an intermediate bridge: |
* |
* encoder ---> bridge B ---> bridge A |
* |
* Here, the output of the encoder feeds to bridge B, and that furthers feeds to |
* bridge A. |
* |
* The driver using the bridge is responsible to make the associations between |
* the encoder and bridges. Once these links are made, the bridges will |
* participate along with encoder functions to perform mode_set/enable/disable |
* through the ops provided in drm_bridge_funcs. |
* |
* drm_bridge, like drm_panel, aren't drm_mode_object entities like planes, |
* crtcs, encoders or connectors. They just provide additional hooks to get the |
* desired output at the end of the encoder chain. |
*/ |
|
static DEFINE_MUTEX(bridge_lock); |
static LIST_HEAD(bridge_list); |
|
/** |
* drm_bridge_add - add the given bridge to the global bridge list |
* |
* @bridge: bridge control structure |
* |
* RETURNS: |
* Unconditionally returns Zero. |
*/ |
int drm_bridge_add(struct drm_bridge *bridge) |
{ |
mutex_lock(&bridge_lock); |
list_add_tail(&bridge->list, &bridge_list); |
mutex_unlock(&bridge_lock); |
|
return 0; |
} |
EXPORT_SYMBOL(drm_bridge_add); |
|
/** |
* drm_bridge_remove - remove the given bridge from the global bridge list |
* |
* @bridge: bridge control structure |
*/ |
void drm_bridge_remove(struct drm_bridge *bridge) |
{ |
mutex_lock(&bridge_lock); |
list_del_init(&bridge->list); |
mutex_unlock(&bridge_lock); |
} |
EXPORT_SYMBOL(drm_bridge_remove); |
|
/** |
* drm_bridge_attach - associate given bridge to our DRM device |
* |
* @dev: DRM device |
* @bridge: bridge control structure |
* |
* called by a kms driver to link one of our encoder/bridge to the given |
* bridge. |
* |
* Note that setting up links between the bridge and our encoder/bridge |
* objects needs to be handled by the kms driver itself |
* |
* RETURNS: |
* Zero on success, error code on failure |
*/ |
int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge) |
{ |
if (!dev || !bridge) |
return -EINVAL; |
|
if (bridge->dev) |
return -EBUSY; |
|
bridge->dev = dev; |
|
if (bridge->funcs->attach) |
return bridge->funcs->attach(bridge); |
|
return 0; |
} |
EXPORT_SYMBOL(drm_bridge_attach); |
|
/** |
* DOC: bridge callbacks |
* |
* The drm_bridge_funcs ops are populated by the bridge driver. The drm |
* internals(atomic and crtc helpers) use the helpers defined in drm_bridge.c |
* These helpers call a specific drm_bridge_funcs op for all the bridges |
* during encoder configuration. |
* |
* When creating a bridge driver, one can implement drm_bridge_funcs op with |
* the help of these rough rules: |
* |
* pre_enable: this contains things needed to be done for the bridge before |
* its clock and timings are enabled by its source. For a bridge, its source |
* is generally the encoder or bridge just before it in the encoder chain. |
* |
* enable: this contains things needed to be done for the bridge once its |
* source is enabled. In other words, enable is called once the source is |
* ready with clock and timing needed by the bridge. |
* |
* disable: this contains things needed to be done for the bridge assuming |
* that its source is still enabled, i.e. clock and timings are still on. |
* |
* post_disable: this contains things needed to be done for the bridge once |
* its source is disabled, i.e. once clocks and timings are off. |
* |
* mode_fixup: this should fixup the given mode for the bridge. It is called |
* after the encoder's mode fixup. mode_fixup can also reject a mode completely |
* if it's unsuitable for the hardware. |
* |
* mode_set: this sets up the mode for the bridge. It assumes that its source |
* (an encoder or a bridge) has set the mode too. |
*/ |
|
/** |
* drm_bridge_mode_fixup - fixup proposed mode for all bridges in the |
* encoder chain |
* @bridge: bridge control structure |
* @mode: desired mode to be set for the bridge |
* @adjusted_mode: updated mode that works for this bridge |
* |
* Calls 'mode_fixup' drm_bridge_funcs op for all the bridges in the |
* encoder chain, starting from the first bridge to the last. |
* |
* Note: the bridge passed should be the one closest to the encoder |
* |
* RETURNS: |
* true on success, false on failure |
*/ |
bool drm_bridge_mode_fixup(struct drm_bridge *bridge, |
const struct drm_display_mode *mode, |
struct drm_display_mode *adjusted_mode) |
{ |
bool ret = true; |
|
if (!bridge) |
return true; |
|
if (bridge->funcs->mode_fixup) |
ret = bridge->funcs->mode_fixup(bridge, mode, adjusted_mode); |
|
ret = ret && drm_bridge_mode_fixup(bridge->next, mode, adjusted_mode); |
|
return ret; |
} |
EXPORT_SYMBOL(drm_bridge_mode_fixup); |
|
/** |
* drm_bridge_disable - calls 'disable' drm_bridge_funcs op for all |
* bridges in the encoder chain. |
* @bridge: bridge control structure |
* |
* Calls 'disable' drm_bridge_funcs op for all the bridges in the encoder |
* chain, starting from the last bridge to the first. These are called before |
* calling the encoder's prepare op. |
* |
* Note: the bridge passed should be the one closest to the encoder |
*/ |
void drm_bridge_disable(struct drm_bridge *bridge) |
{ |
if (!bridge) |
return; |
|
drm_bridge_disable(bridge->next); |
|
bridge->funcs->disable(bridge); |
} |
EXPORT_SYMBOL(drm_bridge_disable); |
|
/** |
* drm_bridge_post_disable - calls 'post_disable' drm_bridge_funcs op for |
* all bridges in the encoder chain. |
* @bridge: bridge control structure |
* |
* Calls 'post_disable' drm_bridge_funcs op for all the bridges in the |
* encoder chain, starting from the first bridge to the last. These are called |
* after completing the encoder's prepare op. |
* |
* Note: the bridge passed should be the one closest to the encoder |
*/ |
void drm_bridge_post_disable(struct drm_bridge *bridge) |
{ |
if (!bridge) |
return; |
|
bridge->funcs->post_disable(bridge); |
|
drm_bridge_post_disable(bridge->next); |
} |
EXPORT_SYMBOL(drm_bridge_post_disable); |
|
/** |
* drm_bridge_mode_set - set proposed mode for all bridges in the |
* encoder chain |
* @bridge: bridge control structure |
* @mode: desired mode to be set for the bridge |
* @adjusted_mode: updated mode that works for this bridge |
* |
* Calls 'mode_set' drm_bridge_funcs op for all the bridges in the |
* encoder chain, starting from the first bridge to the last. |
* |
* Note: the bridge passed should be the one closest to the encoder |
*/ |
void drm_bridge_mode_set(struct drm_bridge *bridge, |
struct drm_display_mode *mode, |
struct drm_display_mode *adjusted_mode) |
{ |
if (!bridge) |
return; |
|
if (bridge->funcs->mode_set) |
bridge->funcs->mode_set(bridge, mode, adjusted_mode); |
|
drm_bridge_mode_set(bridge->next, mode, adjusted_mode); |
} |
EXPORT_SYMBOL(drm_bridge_mode_set); |
|
/** |
* drm_bridge_pre_enable - calls 'pre_enable' drm_bridge_funcs op for all |
* bridges in the encoder chain. |
* @bridge: bridge control structure |
* |
* Calls 'pre_enable' drm_bridge_funcs op for all the bridges in the encoder |
* chain, starting from the last bridge to the first. These are called |
* before calling the encoder's commit op. |
* |
* Note: the bridge passed should be the one closest to the encoder |
*/ |
void drm_bridge_pre_enable(struct drm_bridge *bridge) |
{ |
if (!bridge) |
return; |
|
drm_bridge_pre_enable(bridge->next); |
|
bridge->funcs->pre_enable(bridge); |
} |
EXPORT_SYMBOL(drm_bridge_pre_enable); |
|
/** |
* drm_bridge_enable - calls 'enable' drm_bridge_funcs op for all bridges |
* in the encoder chain. |
* @bridge: bridge control structure |
* |
* Calls 'enable' drm_bridge_funcs op for all the bridges in the encoder |
* chain, starting from the first bridge to the last. These are called |
* after completing the encoder's commit op. |
* |
* Note that the bridge passed should be the one closest to the encoder |
*/ |
void drm_bridge_enable(struct drm_bridge *bridge) |
{ |
if (!bridge) |
return; |
|
bridge->funcs->enable(bridge); |
|
drm_bridge_enable(bridge->next); |
} |
EXPORT_SYMBOL(drm_bridge_enable); |
|
#ifdef CONFIG_OF |
/** |
* of_drm_find_bridge - find the bridge corresponding to the device node in |
* the global bridge list |
* |
* @np: device node |
* |
* RETURNS: |
* drm_bridge control struct on success, NULL on failure |
*/ |
struct drm_bridge *of_drm_find_bridge(struct device_node *np) |
{ |
struct drm_bridge *bridge; |
|
mutex_lock(&bridge_lock); |
|
list_for_each_entry(bridge, &bridge_list, list) { |
if (bridge->of_node == np) { |
mutex_unlock(&bridge_lock); |
return bridge; |
} |
} |
|
mutex_unlock(&bridge_lock); |
return NULL; |
} |
EXPORT_SYMBOL(of_drm_find_bridge); |
#endif |
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MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>"); |
MODULE_DESCRIPTION("DRM bridge infrastructure"); |
MODULE_LICENSE("GPL and additional rights"); |