Something went wrong. Try again.
(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
C
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843// SPDX-License-Identifier: GPL-2.0/* * Componentized device handling. */#include <linux/component.h>#include <linux/device.h>#include <linux/list.h>#include <linux/mutex.h>#include <linux/of.h>#include <linux/slab.h>#include <linux/debugfs.h>
/** * DOC: overview * * The component helper allows drivers to collect a pile of sub-devices, * including their bound drivers, into an aggregate driver. Various subsystems * already provide functions to get hold of such components, e.g. * of_clk_get_by_name(). The component helper can be used when such a * subsystem-specific way to find a device is not available: The component * helper fills the niche of aggregate drivers for specific hardware, where * further standardization into a subsystem would not be practical. The common * example is when a logical device (e.g. a DRM display driver) is spread around * the SoC on various components (scanout engines, blending blocks, transcoders * for various outputs and so on). * * The component helper also doesn't solve runtime dependencies, e.g. for system * suspend and resume operations. See also :ref:`device links<device_link>`. * * Components are registered using component_add() and unregistered with * component_del(), usually from the driver's probe and disconnect functions. * * Aggregate drivers first assemble a component match list of what they need * using component_match_add(). This is then registered as an aggregate driver * using component_master_add_with_match(), and unregistered using * component_master_del(). */
struct component;
struct component_match_array { void *data; int (*compare)(struct device *, void *); int (*compare_typed)(struct device *, int, void *); void (*release)(struct device *, void *); struct component *component; bool duplicate;};
struct component_match { size_t alloc; size_t num; struct component_match_array *compare;};
struct aggregate_device { struct list_head node; bool bound;
const struct component_master_ops *ops; struct device *parent; struct component_match *match;};
struct component { struct list_head node; struct aggregate_device *adev; bool bound;
const struct component_ops *ops; int subcomponent; struct device *dev;};
static DEFINE_MUTEX(component_mutex);static LIST_HEAD(component_list);static LIST_HEAD(aggregate_devices);
#ifdef CONFIG_DEBUG_FS
static struct dentry *component_debugfs_dir;
static int component_devices_show(struct seq_file *s, void *data){ struct aggregate_device *m = s->private; struct component_match *match = m->match; size_t i;
mutex_lock(&component_mutex); seq_printf(s, "%-50s %20s\n", "aggregate_device name", "status"); seq_puts(s, "-----------------------------------------------------------------------\n"); seq_printf(s, "%-50s %20s\n\n", dev_name(m->parent), m->bound ? "bound" : "not bound");
seq_printf(s, "%-50s %20s\n", "device name", "status"); seq_puts(s, "-----------------------------------------------------------------------\n"); for (i = 0; i < match->num; i++) { struct component *component = match->compare[i].component;
seq_printf(s, "%-50s %20s\n", component ? dev_name(component->dev) : "(unknown)", component ? (component->bound ? "bound" : "not bound") : "not registered"); } mutex_unlock(&component_mutex);
return 0;}
DEFINE_SHOW_ATTRIBUTE(component_devices);
static int __init component_debug_init(void){ component_debugfs_dir = debugfs_create_dir("device_component", NULL);
return 0;}
core_initcall(component_debug_init);
static void component_debugfs_add(struct aggregate_device *m){ debugfs_create_file(dev_name(m->parent), 0444, component_debugfs_dir, m, &component_devices_fops);}
static void component_debugfs_del(struct aggregate_device *m){ debugfs_lookup_and_remove(dev_name(m->parent), component_debugfs_dir);}
#else
static void component_debugfs_add(struct aggregate_device *m){ }
static void component_debugfs_del(struct aggregate_device *m){ }
#endif
static struct aggregate_device *__aggregate_find(struct device *parent, const struct component_master_ops *ops){ struct aggregate_device *m;
list_for_each_entry(m, &aggregate_devices, node) if (m->parent == parent && (!ops || m->ops == ops)) return m;
return NULL;}
static struct component *find_component(struct aggregate_device *adev, struct component_match_array *mc){ struct component *c;
list_for_each_entry(c, &component_list, node) { if (c->adev && c->adev != adev) continue;
if (mc->compare && mc->compare(c->dev, mc->data)) return c;
if (mc->compare_typed && mc->compare_typed(c->dev, c->subcomponent, mc->data)) return c; }
return NULL;}
static int find_components(struct aggregate_device *adev){ struct component_match *match = adev->match; size_t i; int ret = 0;
/* * Scan the array of match functions and attach * any components which are found to this adev. */ for (i = 0; i < match->num; i++) { struct component_match_array *mc = &match->compare[i]; struct component *c;
dev_dbg(adev->parent, "Looking for component %zu\n", i);
if (match->compare[i].component) continue;
c = find_component(adev, mc); if (!c) { ret = -ENXIO; break; }
dev_dbg(adev->parent, "found component %s, duplicate %u\n", dev_name(c->dev), !!c->adev);
/* Attach this component to the adev */ match->compare[i].duplicate = !!c->adev; match->compare[i].component = c; c->adev = adev; } return ret;}
/* Detach component from associated aggregate_device */static void remove_component(struct aggregate_device *adev, struct component *c){ size_t i;
/* Detach the component from this adev. */ for (i = 0; i < adev->match->num; i++) if (adev->match->compare[i].component == c) adev->match->compare[i].component = NULL;}
/* * Try to bring up an aggregate device. If component is NULL, we're interested * in this aggregate device, otherwise it's a component which must be present * to try and bring up the aggregate device. * * Returns 1 for successful bringup, 0 if not ready, or -ve errno. */static int try_to_bring_up_aggregate_device(struct aggregate_device *adev, struct component *component){ int ret;
dev_dbg(adev->parent, "trying to bring up adev\n");
if (find_components(adev)) { dev_dbg(adev->parent, "master has incomplete components\n"); return 0; }
if (component && component->adev != adev) { dev_dbg(adev->parent, "master is not for this component (%s)\n", dev_name(component->dev)); return 0; }
if (!devres_open_group(adev->parent, adev, GFP_KERNEL)) return -ENOMEM;
/* Found all components */ ret = adev->ops->bind(adev->parent); if (ret < 0) { devres_release_group(adev->parent, NULL); if (ret != -EPROBE_DEFER) dev_info(adev->parent, "adev bind failed: %d\n", ret); return ret; }
devres_close_group(adev->parent, NULL); adev->bound = true; return 1;}
static int try_to_bring_up_masters(struct component *component){ struct aggregate_device *adev; int ret = 0;
list_for_each_entry(adev, &aggregate_devices, node) { if (!adev->bound) { ret = try_to_bring_up_aggregate_device(adev, component); if (ret != 0) break; } }
return ret;}
static void take_down_aggregate_device(struct aggregate_device *adev){ if (adev->bound) { adev->ops->unbind(adev->parent); devres_release_group(adev->parent, adev); adev->bound = false; }}
/** * component_compare_of - A common component compare function for of_node * @dev: component device * @data: @compare_data from component_match_add_release() * * A common compare function when compare_data is device of_node. e.g. * component_match_add_release(masterdev, &match, component_release_of, * component_compare_of, component_dev_of_node) */int component_compare_of(struct device *dev, void *data){ return device_match_of_node(dev, data);}EXPORT_SYMBOL_GPL(component_compare_of);
/** * component_release_of - A common component release function for of_node * @dev: component device * @data: @compare_data from component_match_add_release() * * About the example, Please see component_compare_of(). */void component_release_of(struct device *dev, void *data){ of_node_put(data);}EXPORT_SYMBOL_GPL(component_release_of);
/** * component_compare_dev - A common component compare function for dev * @dev: component device * @data: @compare_data from component_match_add_release() * * A common compare function when compare_data is struce device. e.g. * component_match_add(masterdev, &match, component_compare_dev, component_dev) */int component_compare_dev(struct device *dev, void *data){ return dev == data;}EXPORT_SYMBOL_GPL(component_compare_dev);
/** * component_compare_dev_name - A common component compare function for device name * @dev: component device * @data: @compare_data from component_match_add_release() * * A common compare function when compare_data is device name string. e.g. * component_match_add(masterdev, &match, component_compare_dev_name, * "component_dev_name") */int component_compare_dev_name(struct device *dev, void *data){ return device_match_name(dev, data);}EXPORT_SYMBOL_GPL(component_compare_dev_name);
static void devm_component_match_release(struct device *parent, void *res){ struct component_match *match = res; unsigned int i;
for (i = 0; i < match->num; i++) { struct component_match_array *mc = &match->compare[i];
if (mc->release) mc->release(parent, mc->data); }
kfree(match->compare);}
static int component_match_realloc(struct component_match *match, size_t num){ struct component_match_array *new;
if (match->alloc == num) return 0;
new = kmalloc_objs(*new, num); if (!new) return -ENOMEM;
if (match->compare) { memcpy(new, match->compare, sizeof(*new) * min(match->num, num)); kfree(match->compare); } match->compare = new; match->alloc = num;
return 0;}
static void __component_match_add(struct device *parent, struct component_match **matchptr, void (*release)(struct device *, void *), int (*compare)(struct device *, void *), int (*compare_typed)(struct device *, int, void *), void *compare_data){ struct component_match *match = *matchptr;
if (IS_ERR(match)) return;
if (!match) { match = devres_alloc(devm_component_match_release, sizeof(*match), GFP_KERNEL); if (!match) { *matchptr = ERR_PTR(-ENOMEM); return; }
devres_add(parent, match);
*matchptr = match; }
if (match->num == match->alloc) { size_t new_size = match->alloc + 16; int ret;
ret = component_match_realloc(match, new_size); if (ret) { *matchptr = ERR_PTR(ret); return; } }
match->compare[match->num].compare = compare; match->compare[match->num].compare_typed = compare_typed; match->compare[match->num].release = release; match->compare[match->num].data = compare_data; match->compare[match->num].component = NULL; match->num++;}
/** * component_match_add_release - add a component match entry with release callback * @parent: parent device of the aggregate driver * @matchptr: pointer to the list of component matches * @release: release function for @compare_data * @compare: compare function to match against all components * @compare_data: opaque pointer passed to the @compare function * * Adds a new component match to the list stored in @matchptr, which the * aggregate driver needs to function. The list of component matches pointed to * by @matchptr must be initialized to NULL before adding the first match. This * only matches against components added with component_add(). * * The allocated match list in @matchptr is automatically released using devm * actions, where upon @release will be called to free any references held by * @compare_data, e.g. when @compare_data is a &device_node that must be * released with of_node_put(). * * See also component_match_add() and component_match_add_typed(). */void component_match_add_release(struct device *parent, struct component_match **matchptr, void (*release)(struct device *, void *), int (*compare)(struct device *, void *), void *compare_data){ __component_match_add(parent, matchptr, release, compare, NULL, compare_data);}EXPORT_SYMBOL(component_match_add_release);
/** * component_match_add_typed - add a component match entry for a typed component * @parent: parent device of the aggregate driver * @matchptr: pointer to the list of component matches * @compare_typed: compare function to match against all typed components * @compare_data: opaque pointer passed to the @compare function * * Adds a new component match to the list stored in @matchptr, which the * aggregate driver needs to function. The list of component matches pointed to * by @matchptr must be initialized to NULL before adding the first match. This * only matches against components added with component_add_typed(). * * The allocated match list in @matchptr is automatically released using devm * actions. * * See also component_match_add_release() and component_match_add_typed(). */void component_match_add_typed(struct device *parent, struct component_match **matchptr, int (*compare_typed)(struct device *, int, void *), void *compare_data){ __component_match_add(parent, matchptr, NULL, NULL, compare_typed, compare_data);}EXPORT_SYMBOL(component_match_add_typed);
static void free_aggregate_device(struct aggregate_device *adev){ struct component_match *match = adev->match; int i;
component_debugfs_del(adev); list_del(&adev->node);
if (match) { for (i = 0; i < match->num; i++) { struct component *c = match->compare[i].component; if (c) c->adev = NULL; } }
kfree(adev);}
/** * component_master_add_with_match - register an aggregate driver * @parent: parent device of the aggregate driver * @ops: callbacks for the aggregate driver * @match: component match list for the aggregate driver * * Registers a new aggregate driver consisting of the components added to @match * by calling one of the component_match_add() functions. Once all components in * @match are available, it will be assembled by calling * &component_master_ops.bind from @ops. Must be unregistered by calling * component_master_del(). */int component_master_add_with_match(struct device *parent, const struct component_master_ops *ops, struct component_match *match){ struct aggregate_device *adev; int ret;
/* Reallocate the match array for its true size */ ret = component_match_realloc(match, match->num); if (ret) return ret;
adev = kzalloc_obj(*adev); if (!adev) return -ENOMEM;
adev->parent = parent; adev->ops = ops; adev->match = match;
component_debugfs_add(adev); /* Add to the list of available aggregate devices. */ mutex_lock(&component_mutex); list_add(&adev->node, &aggregate_devices);
ret = try_to_bring_up_aggregate_device(adev, NULL);
if (ret < 0) free_aggregate_device(adev);
mutex_unlock(&component_mutex);
return ret < 0 ? ret : 0;}EXPORT_SYMBOL_GPL(component_master_add_with_match);
/** * component_master_del - unregister an aggregate driver * @parent: parent device of the aggregate driver * @ops: callbacks for the aggregate driver * * Unregisters an aggregate driver registered with * component_master_add_with_match(). If necessary the aggregate driver is first * disassembled by calling &component_master_ops.unbind from @ops. */void component_master_del(struct device *parent, const struct component_master_ops *ops){ struct aggregate_device *adev;
mutex_lock(&component_mutex); adev = __aggregate_find(parent, ops); if (adev) { take_down_aggregate_device(adev); free_aggregate_device(adev); } mutex_unlock(&component_mutex);}EXPORT_SYMBOL_GPL(component_master_del);
bool component_master_is_bound(struct device *parent, const struct component_master_ops *ops){ struct aggregate_device *adev;
guard(mutex)(&component_mutex); adev = __aggregate_find(parent, ops); if (!adev) return 0;
return adev->bound;}EXPORT_SYMBOL_GPL(component_master_is_bound);
static void component_unbind(struct component *component, struct aggregate_device *adev, void *data){ if (WARN_ON(!component->bound)) return;
dev_dbg(adev->parent, "unbinding %s component %p (ops %ps)\n", dev_name(component->dev), component, component->ops);
if (component->ops && component->ops->unbind) component->ops->unbind(component->dev, adev->parent, data); component->bound = false;
/* Release all resources claimed in the binding of this component */ devres_release_group(component->dev, component);}
/** * component_unbind_all - unbind all components of an aggregate driver * @parent: parent device of the aggregate driver * @data: opaque pointer, passed to all components * * Unbinds all components of the aggregate device by passing @data to their * &component_ops.unbind functions. Should be called from * &component_master_ops.unbind. */void component_unbind_all(struct device *parent, void *data){ struct aggregate_device *adev; struct component *c; size_t i;
WARN_ON(!mutex_is_locked(&component_mutex));
adev = __aggregate_find(parent, NULL); if (!adev) return;
/* Unbind components in reverse order */ for (i = adev->match->num; i--; ) if (!adev->match->compare[i].duplicate) { c = adev->match->compare[i].component; component_unbind(c, adev, data); }}EXPORT_SYMBOL_GPL(component_unbind_all);
static int component_bind(struct component *component, struct aggregate_device *adev, void *data){ int ret;
/* * Each component initialises inside its own devres group. * This allows us to roll-back a failed component without * affecting anything else. */ if (!devres_open_group(adev->parent, NULL, GFP_KERNEL)) return -ENOMEM;
/* * Also open a group for the device itself: this allows us * to release the resources claimed against the sub-device * at the appropriate moment. */ if (!devres_open_group(component->dev, component, GFP_KERNEL)) { devres_release_group(adev->parent, NULL); return -ENOMEM; }
dev_dbg(adev->parent, "binding %s (ops %ps)\n", dev_name(component->dev), component->ops);
ret = component->ops->bind(component->dev, adev->parent, data); if (!ret) { component->bound = true;
/* * Close the component device's group so that resources * allocated in the binding are encapsulated for removal * at unbind. Remove the group on the DRM device as we * can clean those resources up independently. */ devres_close_group(component->dev, NULL); devres_remove_group(adev->parent, NULL);
dev_info(adev->parent, "bound %s (ops %ps)\n", dev_name(component->dev), component->ops); } else { devres_release_group(component->dev, NULL); devres_release_group(adev->parent, NULL);
if (ret != -EPROBE_DEFER) dev_err(adev->parent, "failed to bind %s (ops %ps): %d\n", dev_name(component->dev), component->ops, ret); }
return ret;}
/** * component_bind_all - bind all components of an aggregate driver * @parent: parent device of the aggregate driver * @data: opaque pointer, passed to all components * * Binds all components of the aggregate @dev by passing @data to their * &component_ops.bind functions. Should be called from * &component_master_ops.bind. */int component_bind_all(struct device *parent, void *data){ struct aggregate_device *adev; struct component *c; size_t i; int ret = 0;
WARN_ON(!mutex_is_locked(&component_mutex));
adev = __aggregate_find(parent, NULL); if (!adev) return -EINVAL;
/* Bind components in match order */ for (i = 0; i < adev->match->num; i++) if (!adev->match->compare[i].duplicate) { c = adev->match->compare[i].component; ret = component_bind(c, adev, data); if (ret) break; }
if (ret != 0) { for (; i > 0; i--) if (!adev->match->compare[i - 1].duplicate) { c = adev->match->compare[i - 1].component; component_unbind(c, adev, data); } }
return ret;}EXPORT_SYMBOL_GPL(component_bind_all);
static int __component_add(struct device *dev, const struct component_ops *ops, int subcomponent){ struct component *component; int ret;
component = kzalloc_obj(*component); if (!component) return -ENOMEM;
component->ops = ops; component->dev = dev; component->subcomponent = subcomponent;
dev_dbg(dev, "adding component (ops %ps)\n", ops);
mutex_lock(&component_mutex); list_add_tail(&component->node, &component_list);
ret = try_to_bring_up_masters(component); if (ret < 0) { if (component->adev) remove_component(component->adev, component); list_del(&component->node);
kfree(component); } mutex_unlock(&component_mutex);
return ret < 0 ? ret : 0;}
/** * component_add_typed - register a component * @dev: component device * @ops: component callbacks * @subcomponent: nonzero identifier for subcomponents * * Register a new component for @dev. Functions in @ops will be call when the * aggregate driver is ready to bind the overall driver by calling * component_bind_all(). See also &struct component_ops. * * @subcomponent must be nonzero and is used to differentiate between multiple * components registered on the same device @dev. These components are match * using component_match_add_typed(). * * The component needs to be unregistered at driver unload/disconnect by * calling component_del(). * * See also component_add(). */int component_add_typed(struct device *dev, const struct component_ops *ops, int subcomponent){ if (WARN_ON(subcomponent == 0)) return -EINVAL;
return __component_add(dev, ops, subcomponent);}EXPORT_SYMBOL_GPL(component_add_typed);
/** * component_add - register a component * @dev: component device * @ops: component callbacks * * Register a new component for @dev. Functions in @ops will be called when the * aggregate driver is ready to bind the overall driver by calling * component_bind_all(). See also &struct component_ops. * * The component needs to be unregistered at driver unload/disconnect by * calling component_del(). * * See also component_add_typed() for a variant that allows multiple different * components on the same device. */int component_add(struct device *dev, const struct component_ops *ops){ return __component_add(dev, ops, 0);}EXPORT_SYMBOL_GPL(component_add);
/** * component_del - unregister a component * @dev: component device * @ops: component callbacks * * Unregister a component added with component_add(). If the component is bound * into an aggregate driver, this will force the entire aggregate driver, including * all its components, to be unbound. */void component_del(struct device *dev, const struct component_ops *ops){ struct component *c, *component = NULL;
mutex_lock(&component_mutex); list_for_each_entry(c, &component_list, node) if (c->dev == dev && c->ops == ops) { list_del(&c->node); component = c; break; }
if (component && component->adev) { take_down_aggregate_device(component->adev); remove_component(component->adev, component); }
mutex_unlock(&component_mutex);
WARN_ON(!component); kfree(component);}EXPORT_SYMBOL_GPL(component_del);