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path: root/drivers/base/component.c
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2020-03-18component: allow missing unbind callbackMarco Felsch
The component framework reuses the devres managed functions. There is no need to specify an unbind() callback if the driver only wants to release the devres managed resources. The bind/unbind is like the probe/remove pair. The bind/probe is necessary and the unbind/remove is optional. Signed-off-by: Marco Felsch <m.felsch@pengutronix.de> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> Link: https://lore.kernel.org/r/20200227104547.30085-1-m.felsch@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14component: do not dereference opaque pointer in debugfsLubomir Rintel
The match data does not have to be a struct device pointer, and indeed very often is not. Attempt to treat it as such easily results in a crash. For the components that are not registered, we don't know which device is missing. Once it it is there, we can use the struct component to get the device and whether it's bound or not. Fixes: 59e73854b5fd ('component: add debugfs support') Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Cc: stable <stable@vger.kernel.org> Cc: Arnaud Pouliquen <arnaud.pouliquen@st.com> Link: https://lore.kernel.org/r/20191118115431.63626-1-lkundrak@v3.sk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14drivers/component: remove modular codeMasahiro Yamada
drivers/base/Makefile always adds component.o to obj-y, like this: obj-y := component.o core.o bus.o dd.o syscore.o \ Hence it is never compiled as a module. Remove useless modular code. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20191218144307.19243-1-masahiroy@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-19drivers/component: kerneldoc polishDaniel Vetter
Polish the kerneldoc a bit with suggestions from Randy. v2: Randy found another typo: s/compent/component/ Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Ramalingam C <ramalingam.c@intel.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08components: multiple components for a deviceDaniel Vetter
Component framework is extended to support multiple components for a struct device. These will be matched with different masters based on its sub component value. We are introducing this, as I915 needs two different components with different subcomponent value, which will be matched to two different component masters(Audio and HDCP) based on the subcomponent values. v2: Add documenation. v3: Rebase on top of updated documenation. v4: Review from Rafael: - Remove redundant "This" from kerneldoc (also in the previous patch) - Streamline the logic in find_component() a bit. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v1 code) Signed-off-by: Ramalingam C <ramalingam.c@intel.com> (v1 commit message) Cc: Ramalingam C <ramalingam.c@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20190207232759.14553-2-daniel.vetter@ffwll.ch
2019-02-08component: Add documentationDaniel Vetter
While typing these I think doing an s/component_master/aggregate/ would be useful: - it's shorter :-) - I think component/aggregate is much more meaningful naming than component/puppetmaster or something like that. At least to my English ear "aggregate" emphasizes much more the "assemble a pile of things into something bigger" aspect, and there's not really much of a control hierarchy between aggregate and constituing components. But that's way more than a quick doc typing exercise ... Thanks to Ram for commenting on an initial draft of these docs. v2: Review from Rafael: - git add Documenation/driver-api/component.rst - lots of polish to the wording + spelling fixes. v3: Review from Russell: - s/framework/helper - clarify the documentation for component_match_add functions. v4: Remove a few superflous "This". Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "C, Ramalingam" <ramalingam.c@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190207232759.14553-1-daniel.vetter@ffwll.ch
2018-12-20component: convert to DEFINE_SHOW_ATTRIBUTEYangtao Li
Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-16component: fix loop condition to call unbind() if bind() failsBanajit Goswami
During component_bind_all(), if bind() fails for any particular component associated with a master, unbind() should be called for all previous components in that master's match array, whose bind() might have completed successfully. As per the current logic, if bind() fails for the component at position 'n' in the master's match array, it would start calling unbind() from component in 'n'th position itself and work backwards, and will always skip calling unbind() for component in 0th position in the master's match array. Fix this by updating the loop condition, and the logic to refer to the components in master's match array, so that unbind() is called for all components starting from 'n-1'st position in the array, until (and including) component in 0th position. Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-18component: add debugfs supportMaciej Purski
Currently there is no information in any vfs about which devices a master component consists of, what makes debugging hard if one of the component devices fails to register. Add 'device_component' directory to debugfs. Create a new file for each component master, when it has been added. Remove it on a master deletion. Show a list of devices required by the given master and their status (registered or not). This provides an easy way to check, which device has failed to register if the given master device is not available in the system. Signed-off-by: Maciej Purski <m.purski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07driver core: Remove redundant license textGreg Kroah-Hartman
Now that the SPDX tag is in all driver core files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07driver core: add SPDX identifiers to all driver core filesGreg Kroah-Hartman
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the driver core files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: William Breathitt Gray <vilhelm.gray@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-14Merge 4.5-rc4 into driver-core-nextGreg Kroah-Hartman
We want the fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-11component: remove device from master match list on failed addDaniel Stone
Calling component_add() may result in the completion of a set of devices, which will try to bring up a master. In bringing the master up, we populate its match array with the current set of children. If binding any of the devices fails, component_add() itself will fail, free the struct component entry, and return to the caller. The now-freed entry is never removed from the master's match array, and will later be used in a futile attempt to bind to freed memory. Bring component_add's behaviour on failure to bring up a master into line with component_del by removing the (to-be-freed) component from the master's match array. The specific case which broke was: - rockchip_drm_drv adds a component master - dwhdmi_rockchip adds a child component in probe (master incomplete) - rockchip_drm_vop adds two children in probe, which completes the set - inside component_add, we try to bring up the master, having populated the master's match array, and fail with EPROBE_DEFER from dwhdmi_rockchip; we delete the putative component - rockchip_drm_vop's probe fails and returns EPROBE_DEFER - we later re-probe rockchip_drm_vop and add the component; the master is complete, so we attempt to bring it up again - walking the match array, we find the previous child, whose master pointer doesn't match (as it has been freed in the meantime) - rockchip_drm_vop probe fails, and will never be attempted again Fixes: ffc30b74fd6d01588bd3fdebc3b1acc0857e6fc8 Signed-off-by: Daniel Stone <daniels@collabora.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Thierry Reding <treding@nvidia.com> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-02-09component: remove impossible conditionSudip Mukherjee
We will be evaluating this condition only if match->num == match->alloc and that means we have already dereferenced match which implies match can not be NULL at this point. Moreover we have done a NULL check on match just before this. Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27component: Detach components when deleting master structJon Medhurst (Tixy)
component_master_add_with_match calls find_components which, if any components already exist, it attaches to the master struct. However, if we later encounter an error the master struct is deleted, leaving components with a dangling pointer to it. If the error was a temporary one, e.g. for probe deferral, then when the master device is re-probed, it will fail to find the required components as they appear to already be attached to a master. Fix this by nulling components pointers to the master struct when it is deleted. This code is factored out into a separate function so it can be shared with component_master_del. Signed-off-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-01-26component: fix crash on x86_64 with hda audio driversRussell King
Maarten reports that the addition of releasing match data to the component helper results in a general protection fault on x86_64. This is caused by the devm resources being freed in reverse order to their allocation, which caused a use-after-free of the match array. Switch the match array to be a more conventional kmalloc/kfree() affair, explicitly freeing it along with the parent match data structure. Reported-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Fixes: ce657b1cddf1 ("component: add support for releasing match data") Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-12-07component: add support for releasing match dataRussell King
The component helper treats the void match data pointer as an opaque object which needs no further management. When device nodes being passed, this is not true: the caller should pass its refcount to the component helper, and there should be a way to drop the refcount when the matching information is destroyed. This patch provides a per-match release method in addition to the match method to solve this issue. Rather than using component_match_add(), users should use component_match_add_release() which takes an additional function pointer for releasing this reference. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-12-07component: track components via array rather than listRussell King
Since we now have an array which defines each component, maintain the components to be bound in the array rather than a separate list. We also need duplicate tracking so we can eliminate multiple bind calls for the same component: we preserve the list-based component order in that the first match which adds the component determines its position. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-12-07component: move check for unbound master into try_to_bring_up_masters()Russell King
Clean up the code a little; we don't need to check that the master is unbound for every invocation of try_to_bring_up_master(), so let's move it to where it's really needed - try_to_bring_up_masters(), where we may encounter already bound masters. Reviewed-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-12-07component: remove old add_components methodRussell King
Now that drivers create an array of component matches at probe time, we can retire the old methods. This involves removing the add_components master method, and removing component_master_add_child() from public view. We also remove component_add_master() as that interface is no longer useful. Acked-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-04component: fix bug with legacy APIRussell King
Sachin Kamat reports that "component: add support for component match array" broke Exynos DRM due to a NULL pointer deref. Fix this. Reported-by: Sachin Kamat <sachin.kamat@samsung.com> Tested-by: Sachin Kamat <sachin.kamat@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-03component: add support for component match arrayRussell King
Add support for generating a set of component matches at master probe time, and submitting them to the component layer. This allows the component layer to perform the matches internally without needing to call into the master driver, and allows for further restructuring of the component helper. Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-03component: ignore multiple additions of the same componentRussell King
Permit masters to call component_master_add_child() and match the same child multiple times. This may happen if there's multiple connections to a single component device from other devices. In such scenarios, we should not return a failure, but instead ignore the attempt. Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-03component: fix missed cleanup in case of devres failureRussell King
In try_to_bring_up_master(), we tear down the master's component list for each error case, except for devres group failure. Fix this oversight by making the code less prone to such mistakes. Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-02-07drivers/base: fix devres handling for master deviceRussell King
We weren't handling the devres issues for the master device failing a bind, or being unbound properly. Add a devres group to contain these, and release the resources at the appropriate points. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10drivers/base: provide an infrastructure for componentised subsystemsRussell King
Subsystems such as ALSA, DRM and others require a single card-level device structure to represent a subsystem. However, firmware tends to describe the individual devices and the connections between them. Therefore, we need a way to gather up the individual component devices together, and indicate when we have all the component devices. We do this in DT by providing a "superdevice" node which specifies the components, eg: imx-drm { compatible = "fsl,drm"; crtcs = <&ipu1>; connectors = <&hdmi>; }; The superdevice is declared into the component support, along with the subcomponents. The superdevice receives callbacks to locate the subcomponents, and identify when all components are present. At this point, we bind the superdevice, which causes the appropriate subsystem to be initialised in the conventional way. When any of the components or superdevice are removed from the system, we unbind the superdevice, thereby taking the subsystem down. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>