linux/drivers/gpu/drm/drm_bridge.c
Sean Paul 5ade071ba1 drm: Add atomic variants for bridge enable/disable
This patch adds atomic variants for all of
pre_enable/enable/disable/post_disable bridge functions. These will be
called from the appropriate atomic helper functions. If the bridge
driver doesn't implement the atomic version of the function, we will
fall back to the vanilla implementation.

Note that some drivers call drm_bridge_disable directly, and these cases
are not covered. It's up to the driver to decide whether to implement
both atomic_disable and disable, or if it's not necessary.

Changes in v3:
- Added to the patchset
Changes in v4:
- Fix up docbook references (Daniel)
Changes in v5:
- None

Link to v3: https://patchwork.freedesktop.org/patch/msgid/20190502194956.218441-4-sean@poorly.run
Link to v4: https://patchwork.freedesktop.org/patch/msgid/20190508160920.144739-4-sean@poorly.run

Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190611160844.257498-4-sean@poorly.run
2019-06-13 13:00:29 -04:00

497 lines
14 KiB
C

/*
* 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 <linux/mutex.h>
#include <drm/drm_bridge.h>
#include <drm/drm_encoder.h>
#include "drm_crtc_internal.h"
/**
* DOC: overview
*
* &struct 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 attached 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 and hence are not visible to userspace. They
* just provide additional hooks to get the desired output at the end of the
* encoder chain.
*
* Bridges can also be chained up using the &drm_bridge.next pointer.
*
* Both legacy CRTC helpers and the new atomic modeset helpers support bridges.
*/
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
*/
void drm_bridge_add(struct drm_bridge *bridge)
{
mutex_lock(&bridge_lock);
list_add_tail(&bridge->list, &bridge_list);
mutex_unlock(&bridge_lock);
}
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 - attach the bridge to an encoder's chain
*
* @encoder: DRM encoder
* @bridge: bridge to attach
* @previous: previous bridge in the chain (optional)
*
* Called by a kms driver to link the bridge to an encoder's chain. The previous
* argument specifies the previous bridge in the chain. If NULL, the bridge is
* linked directly at the encoder's output. Otherwise it is linked at the
* previous bridge's output.
*
* If non-NULL the previous bridge must be already attached by a call to this
* function.
*
* Note that bridges attached to encoders are auto-detached during encoder
* cleanup in drm_encoder_cleanup(), so drm_bridge_attach() should generally
* *not* be balanced with a drm_bridge_detach() in driver code.
*
* RETURNS:
* Zero on success, error code on failure
*/
int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
struct drm_bridge *previous)
{
int ret;
if (!encoder || !bridge)
return -EINVAL;
if (previous && (!previous->dev || previous->encoder != encoder))
return -EINVAL;
if (bridge->dev)
return -EBUSY;
bridge->dev = encoder->dev;
bridge->encoder = encoder;
if (bridge->funcs->attach) {
ret = bridge->funcs->attach(bridge);
if (ret < 0) {
bridge->dev = NULL;
bridge->encoder = NULL;
return ret;
}
}
if (previous)
previous->next = bridge;
else
encoder->bridge = bridge;
return 0;
}
EXPORT_SYMBOL(drm_bridge_attach);
void drm_bridge_detach(struct drm_bridge *bridge)
{
if (WARN_ON(!bridge))
return;
if (WARN_ON(!bridge->dev))
return;
if (bridge->funcs->detach)
bridge->funcs->detach(bridge);
bridge->dev = NULL;
}
/**
* 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.
*
* For detailed specification of the bridge callbacks see &drm_bridge_funcs.
*/
/**
* 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 &drm_bridge_funcs.mode_fixup 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_mode_valid - validate the mode against all bridges in the
* encoder chain.
* @bridge: bridge control structure
* @mode: desired mode to be validated
*
* Calls &drm_bridge_funcs.mode_valid for all the bridges in the encoder
* chain, starting from the first bridge to the last. If at least one bridge
* does not accept the mode the function returns the error code.
*
* Note: the bridge passed should be the one closest to the encoder.
*
* RETURNS:
* MODE_OK on success, drm_mode_status Enum error code on failure
*/
enum drm_mode_status drm_bridge_mode_valid(struct drm_bridge *bridge,
const struct drm_display_mode *mode)
{
enum drm_mode_status ret = MODE_OK;
if (!bridge)
return ret;
if (bridge->funcs->mode_valid)
ret = bridge->funcs->mode_valid(bridge, mode);
if (ret != MODE_OK)
return ret;
return drm_bridge_mode_valid(bridge->next, mode);
}
EXPORT_SYMBOL(drm_bridge_mode_valid);
/**
* drm_bridge_disable - disables all bridges in the encoder chain
* @bridge: bridge control structure
*
* Calls &drm_bridge_funcs.disable 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);
if (bridge->funcs->disable)
bridge->funcs->disable(bridge);
}
EXPORT_SYMBOL(drm_bridge_disable);
/**
* drm_bridge_post_disable - cleans up after disabling all bridges in the encoder chain
* @bridge: bridge control structure
*
* Calls &drm_bridge_funcs.post_disable 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;
if (bridge->funcs->post_disable)
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 &drm_bridge_funcs.mode_set 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,
const struct drm_display_mode *mode,
const 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 - prepares for enabling all
* bridges in the encoder chain
* @bridge: bridge control structure
*
* Calls &drm_bridge_funcs.pre_enable 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);
if (bridge->funcs->pre_enable)
bridge->funcs->pre_enable(bridge);
}
EXPORT_SYMBOL(drm_bridge_pre_enable);
/**
* drm_bridge_enable - enables all bridges in the encoder chain
* @bridge: bridge control structure
*
* Calls &drm_bridge_funcs.enable 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;
if (bridge->funcs->enable)
bridge->funcs->enable(bridge);
drm_bridge_enable(bridge->next);
}
EXPORT_SYMBOL(drm_bridge_enable);
/**
* drm_atomic_bridge_disable - disables all bridges in the encoder chain
* @bridge: bridge control structure
* @state: atomic state being committed
*
* Calls &drm_bridge_funcs.atomic_disable (falls back on
* &drm_bridge_funcs.disable) op for all the bridges in the encoder chain,
* starting from the last bridge to the first. These are called before calling
* &drm_encoder_helper_funcs.atomic_disable
*
* Note: the bridge passed should be the one closest to the encoder
*/
void drm_atomic_bridge_disable(struct drm_bridge *bridge,
struct drm_atomic_state *state)
{
if (!bridge)
return;
drm_atomic_bridge_disable(bridge->next, state);
if (bridge->funcs->atomic_disable)
bridge->funcs->atomic_disable(bridge, state);
else if (bridge->funcs->disable)
bridge->funcs->disable(bridge);
}
EXPORT_SYMBOL(drm_atomic_bridge_disable);
/**
* drm_atomic_bridge_post_disable - cleans up after disabling all bridges in the
* encoder chain
* @bridge: bridge control structure
* @state: atomic state being committed
*
* Calls &drm_bridge_funcs.atomic_post_disable (falls back on
* &drm_bridge_funcs.post_disable) op for all the bridges in the encoder chain,
* starting from the first bridge to the last. These are called after completing
* &drm_encoder_helper_funcs.atomic_disable
*
* Note: the bridge passed should be the one closest to the encoder
*/
void drm_atomic_bridge_post_disable(struct drm_bridge *bridge,
struct drm_atomic_state *state)
{
if (!bridge)
return;
if (bridge->funcs->atomic_post_disable)
bridge->funcs->atomic_post_disable(bridge, state);
else if (bridge->funcs->post_disable)
bridge->funcs->post_disable(bridge);
drm_atomic_bridge_post_disable(bridge->next, state);
}
EXPORT_SYMBOL(drm_atomic_bridge_post_disable);
/**
* drm_atomic_bridge_pre_enable - prepares for enabling all bridges in the
* encoder chain
* @bridge: bridge control structure
* @state: atomic state being committed
*
* Calls &drm_bridge_funcs.atomic_pre_enable (falls back on
* &drm_bridge_funcs.pre_enable) op for all the bridges in the encoder chain,
* starting from the last bridge to the first. These are called before calling
* &drm_encoder_helper_funcs.atomic_enable
*
* Note: the bridge passed should be the one closest to the encoder
*/
void drm_atomic_bridge_pre_enable(struct drm_bridge *bridge,
struct drm_atomic_state *state)
{
if (!bridge)
return;
drm_atomic_bridge_pre_enable(bridge->next, state);
if (bridge->funcs->atomic_pre_enable)
bridge->funcs->atomic_pre_enable(bridge, state);
else if (bridge->funcs->pre_enable)
bridge->funcs->pre_enable(bridge);
}
EXPORT_SYMBOL(drm_atomic_bridge_pre_enable);
/**
* drm_atomic_bridge_enable - enables all bridges in the encoder chain
* @bridge: bridge control structure
* @state: atomic state being committed
*
* Calls &drm_bridge_funcs.atomic_enable (falls back on
* &drm_bridge_funcs.enable) op for all the bridges in the encoder chain,
* starting from the first bridge to the last. These are called after completing
* &drm_encoder_helper_funcs.atomic_enable
*
* Note: the bridge passed should be the one closest to the encoder
*/
void drm_atomic_bridge_enable(struct drm_bridge *bridge,
struct drm_atomic_state *state)
{
if (!bridge)
return;
if (bridge->funcs->atomic_enable)
bridge->funcs->atomic_enable(bridge, state);
else if (bridge->funcs->enable)
bridge->funcs->enable(bridge);
drm_atomic_bridge_enable(bridge->next, state);
}
EXPORT_SYMBOL(drm_atomic_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
MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>");
MODULE_DESCRIPTION("DRM bridge infrastructure");
MODULE_LICENSE("GPL and additional rights");