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Tue, 18 Jun 2019 05:12:23 -0700 (PDT) Date: Tue, 18 Jun 2019 14:12:21 +0200 From: Daniel Vetter To: Cheng-yi Chiang Subject: Re: [PATCH 1/7] video: add HDMI state notifier support Message-ID: <20190618121220.GU12905@phenom.ffwll.local> Mail-Followup-To: Cheng-yi Chiang , Hans Verkuil , linux-kernel , Bartlomiej Zolnierkiewicz , Greg Kroah-Hartman , Philipp Zabel , Mark Brown , Liam Girdwood , Takashi Iwai , Jaroslav Kysela , Russell King , Andrzej Hajda , Laurent Pinchart , David Airlie , Rob Herring , Heiko Stuebner , Doug Anderson , Dylan Reid , tzungbi@chromium.org, linux-media@vger.kernel.org, "moderated list:SOUND - SOC LAYER / DYNAMIC AUDIO POWER MANAGEM..." , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, devicetree@vger.kernel.org, Dariusz Marcinkiewicz References: <20190603043251.226549-1-cychiang@chromium.org> <20190603043251.226549-2-cychiang@chromium.org> <41e7052b-a58c-5a8c-5d94-37237e0c2070@xs4all.nl> <20190603080931.GG21222@phenom.ffwll.local> <20190604072411.GP21222@phenom.ffwll.local> <20190611123455.GD2458@phenom.ffwll.local> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Operating-System: Linux phenom 4.19.0-5-amd64 User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190618_051227_415393_6E6DFDF1 X-CRM114-Status: GOOD ( 55.68 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "moderated list:SOUND - SOC LAYER / DYNAMIC AUDIO POWER MANAGEM..." , Heiko Stuebner , Liam Girdwood , David Airlie , dri-devel@lists.freedesktop.org, Takashi Iwai , Hans Verkuil , Andrzej Hajda , Laurent Pinchart , linux-rockchip@lists.infradead.org, Dylan Reid , linux-media@vger.kernel.org, devicetree@vger.kernel.org, tzungbi@chromium.org, Daniel Vetter , Bartlomiej Zolnierkiewicz , Russell King , Rob Herring , Jaroslav Kysela , linux-arm-kernel@lists.infradead.org, Greg Kroah-Hartman , Doug Anderson , linux-kernel , Mark Brown , Philipp Zabel , Dariusz Marcinkiewicz Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jun 18, 2019 at 07:48:06PM +0800, Cheng-yi Chiang wrote: > On Tue, Jun 11, 2019 at 8:35 PM Daniel Vetter wrote: > > > > On Tue, Jun 11, 2019 at 08:10:38PM +0800, Cheng-yi Chiang wrote: > > > On Tue, Jun 4, 2019 at 3:24 PM Daniel Vetter wrote: > > > > > > > > On Tue, Jun 04, 2019 at 10:32:50AM +0800, Cheng-yi Chiang wrote: > > > > > On Mon, Jun 3, 2019 at 4:09 PM Daniel Vetter wrote: > > > > > > > > > > > > On Mon, Jun 03, 2019 at 09:45:49AM +0200, Hans Verkuil wrote: > > > > > > > On 6/3/19 6:32 AM, Cheng-Yi Chiang wrote: > > > > > > > > From: Hans Verkuil > > > > > > > > > > > > > > > > Add support for HDMI hotplug and EDID notifiers, which is used to convey > > > > > > > > information from HDMI drivers to their CEC and audio counterparts. > > > > > > > > > > > > > > > > Based on an earlier version from Russell King: > > > > > > > > > > > > > > > > https://patchwork.kernel.org/patch/9277043/ > > > > > > > > > > > > > > > > The hdmi_notifier is a reference counted object containing the HDMI state > > > > > > > > of an HDMI device. > > > > > > > > > > > > > > > > When a new notifier is registered the current state will be reported to > > > > > > > > that notifier at registration time. > > > > > > > > > > > > > > > > Based on Hans Verkuil's patch: > > > > > > > > > > > > > > > > https://patchwork.kernel.org/patch/9472521/ > > > > > > > > > > > > > > Erm, you are aware that this patch morphed into a CEC-specific notifier > > > > > > > found in drivers/media/cec/cec-notifier.c? > > > > > > > > > > > > > > I don't think it makes sense to have two notifier implementations in the kernel. > > > > > > > The original intention was to have the notifier deal with both CEC and ASoC > > > > > > > notifications, but there was not enough interest for the ASoC bits at the time > > > > > > > and it was dropped. > > > > > > > > > > > > > > I am planning changes to the cec-notifier API, I hope to work on that this > > > > > > > week. I'll CC you when I post those. Those might be a good starting point > > > > > > > to convert the cec-notifier to an hdmi-notifier as was originally intended. > > > > > > > > > > > > > > I've added your colleague Dariusz Marcinkiewicz to the CC list since he's been > > > > > > > working on some nice cec-notifier improvements as well. > > > > > > > > > > > > We also have some interfaces for drm/alsa interactions around hdmi > > > > > > already in drm/drm_audio_component.h, but it's not used by anything > > > > > > outside of i915. Imo we should extend that, not reinvent a new wheel. > > > > > > > > > > > Hi Daniel, > > > > > Thank you for the pointer. Looking at the ops, it seems that it is > > > > > specific to HDA. > > > > > I am not familiar with drm and HDA. I am not sure how applicable it > > > > > would be to report jack status to ASoC. > > > > > There is a use case in sound/soc/codecs/hdac_hdmi.c though so it > > > > > should be possible. > > > > > > > > Currently hda is the only user, but the idea was to make it more generic. > > > > Jack status in alsa is what drm calls connector status btw. > > > > > > > > So if we can take that as a baseline and extend it (probably needs some > > > > registration boilerplate and helpers to look up the right endpoint using > > > > of/dt for soc systems, we use component.c in i915/hda for this), that > > > > would be great I think. > > > > > > > > > > Another note: notifiers considered evil, imo. Gets the job done for one > > > > > > case, as soon as you have multiple devices and need to make sure you get > > > > > > the update for the right one it all comes crashing down. Please create an > > > > > > api which registers for updates from a specific device only, plus > > > > > > something that has real callbacks (like the drm_audio_component.h thing we > > > > > > started already). > > > > > > > > > > To clarify a bit, this hdmi-notifier indeed supports updating from a > > > > > specific device only. > > > > > hdmi_notifier_get takes a device and return the notifier. > > > > > > > > Hm I missed that, I thought it's global, so one of my usual notifier > > > > concerns addressed. > > > > > > > > > It seems that a major difference between drm_audio_components and > > > > > hdmi-notifier is that > > > > > drm_audio_components defines all supported ops in drm_audio_component_audio_ops. > > > > > On the other hand, hdmi-notifier passes different events using an enum > > > > > like HDMI_CONNECTED and let listener handle different events. > > > > > In this regard I agree with you that drm_audio_component is cleaner. > > > > > Anyway, I will look into it a bit more and see how it works. > > > > > > > > Yeah I think if we could combine the approach, i.e. notifier side for > > > > registration, some _ops structure for the actual notifications, then > > > > there's a solid interface. I just really don't like the opaque void * > > > > interface notifier provides, it encourages abuse way too much. > > > > > > > > Ofc the registration side would then no longer be based on the notifier > > > > datastructure, list_head (like cec-notifier.c) of registeres devices with > > > > their _ops structure should be enough. > > > > -Daniel > > > > > > Hi Daniel, > > > Yes, I agree the above statement that we should have a more solid interface. > > > > > > Hi Hans, > > > I am not sure if I missed the patch. > > > Do you have a estimated timeline for new cec-notifier interface you > > > are working on? > > > It seems that your PoC patch needs Dariusz's patch to work. > > > I would like to seek your advice on whether I can proceed without your > > > patch and Dariusz's patch. > > > > > > I looked through the patch from Dariusz > > > > > > https://lkml.org/lkml/2019/5/21/389 > > > > > > , and saw that you were thinking whether we should use cec-notifier > > > for both HDMI and CEC. > > > > > > https://lkml.org/lkml/2019/5/24/298 > > > > > > Could you please let me know your latest thought on whether we should > > > reuse cec-notifier? > > > > Nah, see later in that thread, I think cec and audio seem to be different > > use-cases. > > > Ack > > But definitely a good idea to sync with Dariusz, I forgot to pull the two > > threads together. Thanks for doing that. > > > > > I agree with you that I should not proceed with hdmi-notifier. Reasons include: > > > 1. Method like cec_notifier_parse_hdmi_phandle can be reused. It is > > > error prone to memory leak if it is implemented by user, like the > > > patch in hdmi-codec.c in this series did not handle the ref count. > > > 2. cec-notifier has a simpler implementation of register / unregister > > > because there is no call chain. I am not aware of the need for > > > hdmi-notifier to support a chain of callbacks. So I think that call > > > chain support can be removed. > > > > > > If I go ahead and add a new interface to register ops to handle > > > connector status report from cec-notifer, based on current > > > cec-notifier, do you think that would work ? > > > I think it might work if I add another cec_notifier object inside > > > dw-hdmi.c, but only for HDMI jack reporting, not for CEC related > > > reporting. > > > > > > And after some investigation, I realize that my requirement is even > > > simpler. I don't need hdmi_event_new_edid and hdmi_event_new_eld in my > > > use case. > > > > Yeah, connector status is how we started with the drm/alsa interface in > > i915 too, but later on had to extend it. I think eventually we'll need it > > all, that's why I suggested to use that as the interface between drm and > > alsa side, but augmented with some register/unregister and bind logic. > > > Hi Daniel, > Sorry for the late reply. > I spent some time investigating how drm_audio_component works. > The coupling of HDA in drm_audio_component framework makes the > register/unregister logic looks complicated to me as I don't use HDA > in my use case. > After some time, I found another patch series which also use component > framework to communicate between drm and mei world. > > https://patchwork.kernel.org/patch/10824527/ > > And from that patch, I realized that I can follow the similar approach > to register a master component on ALSA side, a slave component on DRM > side, and use device and subcomponent to match them. Sorry for the confusion here. My suggestion is _not_ to use the component framework. That's only meant for one-off special case solutions. For that part I think you need to build a new register/unregister/bind/unbind infrastructure, like we have for lots of other things in the kernel already (clocks, gpio, drm_panel, drm_bridge as just a few examples). My suggestion with the i915/hda interface is to build on the actual interface for signalling connector status and exchanging eld and stuff like that. > I should be able to do this without touching anything specific to HDA. > After that, DRM world should be able to use the ops in > drm_audio_component_audio_ops to notify ALSA world some event when > there is something happen in DRM world. > Currently the ops like pin_eld_notify, pin2port are too specific to HDA. > I think I can add an ops to drm_audio_component_audio_ops to convey > connector status. Hm why? The pin2port is maybe not the best one, since port is an intel construct, and pin a hda construct. So we'd need to change those to talk in terms of the higher-level concepts (alsa output pin and drm crtc probably). The other stuff should work a bit better. Either way my idea was to evolve that interface (and put in the place the required type-casting for i915/hda), since more users increases the odds that it actually is a good design. > I will work toward this approach these days. > If you have other thought please let me know. > Thanks! > > > > I just need to report the connector status from synopsys/dw-hdmi.c to > > > codecs/hdmi-codec.c for codec driver to update the jack status. > > > Do you think I can proceed in this direction ? Or do you prefer I wait > > > for a while and work on it based on your new patch. > > > > I think most important part here is that we sync across all the different > > people pushing for better drm/alsa integration. What the solution looks > > like in the end doesn't matter much imo, as long as we don't end up with 3 > > different things :-) > > Totally agree. Anyway just my thoughts, let's keep chatting. Cheers, Daniel > Thanks again! > > > > > Cheers, Daniel > > > > > > > > Thanks a lot! > > > > > > > > > > > > > > > > > > > > Thanks again! > > > > > > > > > > > -Daniel > > > > > > > > > > > > > > > > > > > > Regards, > > > > > > > > > > > > > > Hans > > > > > > > > > > > > > > > > > > > > > > > Modified by Cheng-Yi Chiang: > > > > > > > > - Add a section in MAINTAINER. > > > > > > > > - Changes connected and has_eld to bitfield of unsigned int. > > > > > > > > - Other minor fixes to pass checkpatch.pl --strict checks. > > > > > > > > > > > > > > > > Signed-off-by: Hans Verkuil > > > > > > > > Acked-by: Philipp Zabel > > > > > > > > Signed-off-by: Cheng-Yi Chiang > > > > > > > > --- > > > > > > > > The original patch is at > > > > > > > > https://lore.kernel.org/linux-arm-kernel/20161213150813.37966-2-hverkuil@xs4all.nl > > > > > > > > > > > > > > > > MAINTAINERS | 6 ++ > > > > > > > > drivers/video/Kconfig | 3 + > > > > > > > > drivers/video/Makefile | 1 + > > > > > > > > drivers/video/hdmi-notifier.c | 145 ++++++++++++++++++++++++++++++++++ > > > > > > > > include/linux/hdmi-notifier.h | 112 ++++++++++++++++++++++++++ > > > > > > > > 5 files changed, 267 insertions(+) > > > > > > > > create mode 100644 drivers/video/hdmi-notifier.c > > > > > > > > create mode 100644 include/linux/hdmi-notifier.h > > > > > > > > > > > > > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > > > > > > > index 5cfbea4ce575..ffb7376f9509 100644 > > > > > > > > --- a/MAINTAINERS > > > > > > > > +++ b/MAINTAINERS > > > > > > > > @@ -16676,6 +16676,12 @@ W: https://linuxtv.org > > > > > > > > S: Maintained > > > > > > > > F: drivers/media/platform/vicodec/* > > > > > > > > > > > > > > > > +VIDEO FRAMEWORK > > > > > > > > +M: Hans Verkuil > > > > > > > > +L: linux-media@vger.kernel.org > > > > > > > > +F: drivers/video/hdmi-notifier.* > > > > > > > > +S: Maintained > > > > > > > > + > > > > > > > > VIDEO MULTIPLEXER DRIVER > > > > > > > > M: Philipp Zabel > > > > > > > > L: linux-media@vger.kernel.org > > > > > > > > diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig > > > > > > > > index 83d3d271ca15..000ba9bc0ae7 100644 > > > > > > > > --- a/drivers/video/Kconfig > > > > > > > > +++ b/drivers/video/Kconfig > > > > > > > > @@ -34,6 +34,9 @@ config VIDEOMODE_HELPERS > > > > > > > > config HDMI > > > > > > > > bool > > > > > > > > > > > > > > > > +config HDMI_NOTIFIERS > > > > > > > > + bool > > > > > > > > + > > > > > > > > endif # HAS_IOMEM > > > > > > > > > > > > > > > > if VT > > > > > > > > diff --git a/drivers/video/Makefile b/drivers/video/Makefile > > > > > > > > index df7650adede9..eff4736102ca 100644 > > > > > > > > --- a/drivers/video/Makefile > > > > > > > > +++ b/drivers/video/Makefile > > > > > > > > @@ -1,6 +1,7 @@ > > > > > > > > # SPDX-License-Identifier: GPL-2.0 > > > > > > > > obj-$(CONFIG_VGASTATE) += vgastate.o > > > > > > > > obj-$(CONFIG_HDMI) += hdmi.o > > > > > > > > +obj-$(CONFIG_HDMI_NOTIFIERS) += hdmi-notifier.o > > > > > > > > > > > > > > > > obj-$(CONFIG_VT) += console/ > > > > > > > > obj-$(CONFIG_FB_STI) += console/ > > > > > > > > diff --git a/drivers/video/hdmi-notifier.c b/drivers/video/hdmi-notifier.c > > > > > > > > new file mode 100644 > > > > > > > > index 000000000000..d1eedf661648 > > > > > > > > --- /dev/null > > > > > > > > +++ b/drivers/video/hdmi-notifier.c > > > > > > > > @@ -0,0 +1,145 @@ > > > > > > > > +// SPDX-License-Identifier: GPL-2.0 > > > > > > > > +/* hdmi-notifier.c - notify interested parties of (dis)connect and EDID > > > > > > > > + * events > > > > > > > > + * > > > > > > > > + * Copyright 2016 Russell King > > > > > > > > + * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. > > > > > > > > + * All rights reserved. > > > > > > > > + */ > > > > > > > > + > > > > > > > > +#include > > > > > > > > +#include > > > > > > > > +#include > > > > > > > > +#include > > > > > > > > +#include > > > > > > > > + > > > > > > > > +static LIST_HEAD(hdmi_notifiers); > > > > > > > > +static DEFINE_MUTEX(hdmi_notifiers_lock); > > > > > > > > + > > > > > > > > +struct hdmi_notifier *hdmi_notifier_get(struct device *dev) > > > > > > > > +{ > > > > > > > > + struct hdmi_notifier *n; > > > > > > > > + > > > > > > > > + mutex_lock(&hdmi_notifiers_lock); > > > > > > > > + list_for_each_entry(n, &hdmi_notifiers, head) { > > > > > > > > + if (n->dev == dev) { > > > > > > > > + mutex_unlock(&hdmi_notifiers_lock); > > > > > > > > + kref_get(&n->kref); > > > > > > > > + return n; > > > > > > > > + } > > > > > > > > + } > > > > > > > > + n = kzalloc(sizeof(*n), GFP_KERNEL); > > > > > > > > + if (!n) > > > > > > > > + goto unlock; > > > > > > > > + n->dev = dev; > > > > > > > > + mutex_init(&n->lock); > > > > > > > > + BLOCKING_INIT_NOTIFIER_HEAD(&n->notifiers); > > > > > > > > + kref_init(&n->kref); > > > > > > > > + list_add_tail(&n->head, &hdmi_notifiers); > > > > > > > > +unlock: > > > > > > > > + mutex_unlock(&hdmi_notifiers_lock); > > > > > > > > + return n; > > > > > > > > +} > > > > > > > > +EXPORT_SYMBOL_GPL(hdmi_notifier_get); > > > > > > > > + > > > > > > > > +static void hdmi_notifier_release(struct kref *kref) > > > > > > > > +{ > > > > > > > > + struct hdmi_notifier *n = > > > > > > > > + container_of(kref, struct hdmi_notifier, kref); > > > > > > > > + > > > > > > > > + mutex_lock(&hdmi_notifiers_lock); > > > > > > > > + list_del(&n->head); > > > > > > > > + mutex_unlock(&hdmi_notifiers_lock); > > > > > > > > + kfree(n->edid); > > > > > > > > + kfree(n); > > > > > > > > +} > > > > > > > > + > > > > > > > > +void hdmi_notifier_put(struct hdmi_notifier *n) > > > > > > > > +{ > > > > > > > > + kref_put(&n->kref, hdmi_notifier_release); > > > > > > > > +} > > > > > > > > +EXPORT_SYMBOL_GPL(hdmi_notifier_put); > > > > > > > > + > > > > > > > > +int hdmi_notifier_register(struct hdmi_notifier *n, struct notifier_block *nb) > > > > > > > > +{ > > > > > > > > + int ret = blocking_notifier_chain_register(&n->notifiers, nb); > > > > > > > > + > > > > > > > > + if (ret) > > > > > > > > + return ret; > > > > > > > > + kref_get(&n->kref); > > > > > > > > + mutex_lock(&n->lock); > > > > > > > > + if (n->connected) { > > > > > > > > + blocking_notifier_call_chain(&n->notifiers, HDMI_CONNECTED, n); > > > > > > > > + if (n->edid_size) > > > > > > > > + blocking_notifier_call_chain(&n->notifiers, > > > > > > > > + HDMI_NEW_EDID, n); > > > > > > > > + if (n->has_eld) > > > > > > > > + blocking_notifier_call_chain(&n->notifiers, > > > > > > > > + HDMI_NEW_ELD, n); > > > > > > > > + } > > > > > > > > + mutex_unlock(&n->lock); > > > > > > > > + return 0; > > > > > > > > +} > > > > > > > > +EXPORT_SYMBOL_GPL(hdmi_notifier_register); > > > > > > > > + > > > > > > > > +int hdmi_notifier_unregister(struct hdmi_notifier *n, struct notifier_block *nb) > > > > > > > > +{ > > > > > > > > + int ret = blocking_notifier_chain_unregister(&n->notifiers, nb); > > > > > > > > + > > > > > > > > + if (ret == 0) > > > > > > > > + hdmi_notifier_put(n); > > > > > > > > + return ret; > > > > > > > > +} > > > > > > > > +EXPORT_SYMBOL_GPL(hdmi_notifier_unregister); > > > > > > > > + > > > > > > > > +void hdmi_event_connect(struct hdmi_notifier *n) > > > > > > > > +{ > > > > > > > > + mutex_lock(&n->lock); > > > > > > > > + n->connected = true; > > > > > > > > + blocking_notifier_call_chain(&n->notifiers, HDMI_CONNECTED, n); > > > > > > > > + mutex_unlock(&n->lock); > > > > > > > > +} > > > > > > > > +EXPORT_SYMBOL_GPL(hdmi_event_connect); > > > > > > > > + > > > > > > > > +void hdmi_event_disconnect(struct hdmi_notifier *n) > > > > > > > > +{ > > > > > > > > + mutex_lock(&n->lock); > > > > > > > > + n->connected = false; > > > > > > > > + n->has_eld = false; > > > > > > > > + n->edid_size = 0; > > > > > > > > + blocking_notifier_call_chain(&n->notifiers, HDMI_DISCONNECTED, n); > > > > > > > > + mutex_unlock(&n->lock); > > > > > > > > +} > > > > > > > > +EXPORT_SYMBOL_GPL(hdmi_event_disconnect); > > > > > > > > + > > > > > > > > +int hdmi_event_new_edid(struct hdmi_notifier *n, const void *edid, size_t size) > > > > > > > > +{ > > > > > > > > + mutex_lock(&n->lock); > > > > > > > > + if (n->edid_allocated_size < size) { > > > > > > > > + void *p = kmalloc(size, GFP_KERNEL); > > > > > > > > + > > > > > > > > + if (!p) { > > > > > > > > + mutex_unlock(&n->lock); > > > > > > > > + return -ENOMEM; > > > > > > > > + } > > > > > > > > + kfree(n->edid); > > > > > > > > + n->edid = p; > > > > > > > > + n->edid_allocated_size = size; > > > > > > > > + } > > > > > > > > + memcpy(n->edid, edid, size); > > > > > > > > + n->edid_size = size; > > > > > > > > + blocking_notifier_call_chain(&n->notifiers, HDMI_NEW_EDID, n); > > > > > > > > + mutex_unlock(&n->lock); > > > > > > > > + return 0; > > > > > > > > +} > > > > > > > > +EXPORT_SYMBOL_GPL(hdmi_event_new_edid); > > > > > > > > + > > > > > > > > +void hdmi_event_new_eld(struct hdmi_notifier *n, const u8 eld[128]) > > > > > > > > +{ > > > > > > > > + mutex_lock(&n->lock); > > > > > > > > + memcpy(n->eld, eld, sizeof(n->eld)); > > > > > > > > + n->has_eld = true; > > > > > > > > + blocking_notifier_call_chain(&n->notifiers, HDMI_NEW_ELD, n); > > > > > > > > + mutex_unlock(&n->lock); > > > > > > > > +} > > > > > > > > +EXPORT_SYMBOL_GPL(hdmi_event_new_eld); > > > > > > > > diff --git a/include/linux/hdmi-notifier.h b/include/linux/hdmi-notifier.h > > > > > > > > new file mode 100644 > > > > > > > > index 000000000000..c8f35110e3e3 > > > > > > > > --- /dev/null > > > > > > > > +++ b/include/linux/hdmi-notifier.h > > > > > > > > @@ -0,0 +1,112 @@ > > > > > > > > +/* SPDX-License-Identifier: GPL-2.0 > > > > > > > > + * hdmi-notifier.h - notify interested parties of (dis)connect and EDID > > > > > > > > + * events > > > > > > > > + * > > > > > > > > + * Copyright 2016 Russell King > > > > > > > > + * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. > > > > > > > > + * All rights reserved. > > > > > > > > + */ > > > > > > > > + > > > > > > > > +#ifndef LINUX_HDMI_NOTIFIER_H > > > > > > > > +#define LINUX_HDMI_NOTIFIER_H > > > > > > > > + > > > > > > > > +#include > > > > > > > > +#include > > > > > > > > +#include > > > > > > > > + > > > > > > > > +enum { > > > > > > > > + HDMI_CONNECTED, > > > > > > > > + HDMI_DISCONNECTED, > > > > > > > > + HDMI_NEW_EDID, > > > > > > > > + HDMI_NEW_ELD, > > > > > > > > +}; > > > > > > > > + > > > > > > > > +struct device; > > > > > > > > + > > > > > > > > +struct hdmi_notifier { > > > > > > > > + /* Lock to protect callback registration and notification. */ > > > > > > > > + struct mutex lock; > > > > > > > > + struct list_head head; > > > > > > > > + struct kref kref; > > > > > > > > + struct blocking_notifier_head notifiers; > > > > > > > > + struct device *dev; > > > > > > > > + > > > > > > > > + /* Current state */ > > > > > > > > + unsigned int connected : 1; > > > > > > > > + unsigned int has_eld : 1; > > > > > > > > + unsigned char eld[128]; > > > > > > > > + void *edid; > > > > > > > > + size_t edid_size; > > > > > > > > + size_t edid_allocated_size; > > > > > > > > +}; > > > > > > > > + > > > > > > > > +/** > > > > > > > > + * hdmi_notifier_get - find or create a new hdmi_notifier for the given device. > > > > > > > > + * @dev: device that sends the events. > > > > > > > > + * > > > > > > > > + * If a notifier for device @dev already exists, then increase the refcount > > > > > > > > + * and return that notifier. > > > > > > > > + * > > > > > > > > + * If it doesn't exist, then allocate a new notifier struct and return a > > > > > > > > + * pointer to that new struct. > > > > > > > > + * > > > > > > > > + * Return NULL if the memory could not be allocated. > > > > > > > > + */ > > > > > > > > +struct hdmi_notifier *hdmi_notifier_get(struct device *dev); > > > > > > > > + > > > > > > > > +/** > > > > > > > > + * hdmi_notifier_put - decrease refcount and delete when the refcount reaches 0. > > > > > > > > + * @n: notifier > > > > > > > > + */ > > > > > > > > +void hdmi_notifier_put(struct hdmi_notifier *n); > > > > > > > > + > > > > > > > > +/** > > > > > > > > + * hdmi_notifier_register - register the notifier with the notifier_block. > > > > > > > > + * @n: the HDMI notifier > > > > > > > > + * @nb: the notifier_block > > > > > > > > + */ > > > > > > > > +int hdmi_notifier_register(struct hdmi_notifier *n, struct notifier_block *nb); > > > > > > > > + > > > > > > > > +/** > > > > > > > > + * hdmi_notifier_unregister - unregister the notifier with the notifier_block. > > > > > > > > + * @n: the HDMI notifier > > > > > > > > + * @nb: the notifier_block > > > > > > > > + */ > > > > > > > > +int hdmi_notifier_unregister(struct hdmi_notifier *n, > > > > > > > > + struct notifier_block *nb); > > > > > > > > + > > > > > > > > +/** > > > > > > > > + * hdmi_event_connect - send a connect event. > > > > > > > > + * @n: the HDMI notifier > > > > > > > > + * > > > > > > > > + * Send an HDMI_CONNECTED event to any registered parties. > > > > > > > > + */ > > > > > > > > +void hdmi_event_connect(struct hdmi_notifier *n); > > > > > > > > + > > > > > > > > +/** > > > > > > > > + * hdmi_event_disconnect - send a disconnect event. > > > > > > > > + * @n: the HDMI notifier > > > > > > > > + * > > > > > > > > + * Send an HDMI_DISCONNECTED event to any registered parties. > > > > > > > > + */ > > > > > > > > +void hdmi_event_disconnect(struct hdmi_notifier *n); > > > > > > > > + > > > > > > > > +/** > > > > > > > > + * hdmi_event_new_edid - send a new EDID event. > > > > > > > > + * @n: the HDMI notifier > > > > > > > > + * > > > > > > > > + * Send an HDMI_NEW_EDID event to any registered parties. > > > > > > > > + * This function will make a copy the EDID so it can return -ENOMEM if > > > > > > > > + * no memory could be allocated. > > > > > > > > + */ > > > > > > > > +int hdmi_event_new_edid(struct hdmi_notifier *n, const void *edid, size_t size); > > > > > > > > + > > > > > > > > +/** > > > > > > > > + * hdmi_event_new_eld - send a new ELD event. > > > > > > > > + * @n: the HDMI notifier > > > > > > > > + * > > > > > > > > + * Send an HDMI_NEW_ELD event to any registered parties. > > > > > > > > + */ > > > > > > > > +void hdmi_event_new_eld(struct hdmi_notifier *n, const u8 eld[128]); > > > > > > > > + > > > > > > > > +#endif > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > Daniel Vetter > > > > > > Software Engineer, Intel Corporation > > > > > > http://blog.ffwll.ch > > > > > > > > -- > > > > Daniel Vetter > > > > Software Engineer, Intel Corporation > > > > http://blog.ffwll.ch > > > > -- > > Daniel Vetter > > Software Engineer, Intel Corporation > > http://blog.ffwll.ch -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel