// SPDX-License-Identifier: GPL-2.0/* * Componentized device handling. * * This is work in progress. We gather up the component devices into a list, * and bind them when instructed. At the moment, we're specific to the DRM * subsystem, and only handles one master device, but this doesn't have to be * the case. */#include <linux/component.h>#include <linux/device.h>#include <linux/kref.h>#include <linux/list.h>#include <linux/mutex.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 master { struct list_head node; bool bound; const struct component_master_ops *ops; struct device *dev; struct component_match *match;}; struct component { struct list_head node; struct master *master; 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(masters); #ifdef CONFIG_DEBUG_FS static struct dentry *component_debugfs_dir; static int component_devices_show(struct seq_file *s, void *data){ struct master *m = s->private; struct component_match *match = m->match; size_t i; mutex_lock(&component_mutex); seq_printf(s, "%-40s %20s\n", "master name", "status"); seq_puts(s, "-------------------------------------------------------------\n"); seq_printf(s, "%-40s %20s\n\n", dev_name(m->dev), m->bound ? "bound" : "not bound"); seq_printf(s, "%-40s %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, "%-40s %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_master_debugfs_add(struct master *m){ debugfs_create_file(dev_name(m->dev), 0444, component_debugfs_dir, m, &component_devices_fops);} static void component_master_debugfs_del(struct master *m){ debugfs_remove(debugfs_lookup(dev_name(m->dev), component_debugfs_dir));} #else static void component_master_debugfs_add(struct master *m){ } static void component_master_debugfs_del(struct master *m){ } #endif static struct master *__master_find(struct device *dev, const struct component_master_ops *ops){ struct master *m; list_for_each_entry(m, &masters, node) if (m->dev == dev && (!ops || m->ops == ops)) return m; return NULL;} static struct component *find_component(struct master *master, struct component_match_array *mc){ struct component *c; list_for_each_entry(c, &component_list, node) { if (c->master && c->master != master) 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 master *master){ struct component_match *match = master->match; size_t i; int ret = 0; /* * Scan the array of match functions and attach * any components which are found to this master. */ for (i = 0; i < match->num; i++) { struct component_match_array *mc = &match->compare[i]; struct component *c; dev_dbg(master->dev, "Looking for component %zu\n", i); if (match->compare[i].component) continue; c = find_component(master, mc); if (!c) { ret = -ENXIO; break; } dev_dbg(master->dev, "found component %s, duplicate %u\n", dev_name(c->dev), !!c->master); /* Attach this component to the master */ match->compare[i].duplicate = !!c->master; match->compare[i].component = c; c->master = master; } return ret;} /* Detach component from associated master */static void remove_component(struct master *master, struct component *c){ size_t i; /* Detach the component from this master. */ for (i = 0; i < master->match->num; i++) if (master->match->compare[i].component == c) master->match->compare[i].component = NULL;} /* * Try to bring up a master. If component is NULL, we're interested in * this master, otherwise it's a component which must be present to try * and bring up the master. * * Returns 1 for successful bringup, 0 if not ready, or -ve errno. */static int try_to_bring_up_master(struct master *master, struct component *component){ int ret; dev_dbg(master->dev, "trying to bring up master\n"); if (find_components(master)) { dev_dbg(master->dev, "master has incomplete components\n"); return 0; } if (component && component->master != master) { dev_dbg(master->dev, "master is not for this component (%s)\n", dev_name(component->dev)); return 0; } if (!devres_open_group(master->dev, NULL, GFP_KERNEL)) return -ENOMEM; /* Found all components */ ret = master->ops->bind(master->dev); if (ret < 0) { devres_release_group(master->dev, NULL); if (ret != -EPROBE_DEFER) dev_info(master->dev, "master bind failed: %d\n", ret); return ret; } master->bound = true; return 1;} static int try_to_bring_up_masters(struct component *component){ struct master *m; int ret = 0; list_for_each_entry(m, &masters, node) { if (!m->bound) { ret = try_to_bring_up_master(m, component); if (ret != 0) break; } } return ret;} static void take_down_master(struct master *master){ if (master->bound) { master->ops->unbind(master->dev); devres_release_group(master->dev, NULL); master->bound = false; }} static void component_match_release(struct device *master, struct component_match *match){ unsigned int i; for (i = 0; i < match->num; i++) { struct component_match_array *mc = &match->compare[i]; if (mc->release) mc->release(master, mc->data); } kfree(match->compare);} static void devm_component_match_release(struct device *dev, void *res){ component_match_release(dev, res);} static int component_match_realloc(struct device *dev, struct component_match *match, size_t num){ struct component_match_array *new; if (match->alloc == num) return 0; new = kmalloc_array(num, sizeof(*new), GFP_KERNEL); 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 *master, 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(master, match); *matchptr = match; } if (match->num == match->alloc) { size_t new_size = match->alloc + 16; int ret; ret = component_match_realloc(master, 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 * @master: device with 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 @master * 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 *master, struct component_match **matchptr, void (*release)(struct device *, void *), int (*compare)(struct device *, void *), void *compare_data){ __component_match_add(master, 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 * @master: device with 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 @master * 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 *master, struct component_match **matchptr, int (*compare_typed)(struct device *, int, void *), void *compare_data){ __component_match_add(master, matchptr, NULL, NULL, compare_typed, compare_data);}EXPORT_SYMBOL(component_match_add_typed); static void free_master(struct master *master){ struct component_match *match = master->match; int i; component_master_debugfs_del(master); list_del(&master->node); if (match) { for (i = 0; i < match->num; i++) { struct component *c = match->compare[i].component; if (c) c->master = NULL; } } kfree(master);} /** * component_master_add_with_match - register an aggregate driver * @dev: device with 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 *dev, const struct component_master_ops *ops, struct component_match *match){ struct master *master; int ret; /* Reallocate the match array for its true size */ ret = component_match_realloc(dev, match, match->num); if (ret) return ret; master = kzalloc(sizeof(*master), GFP_KERNEL); if (!master) return -ENOMEM; master->dev = dev; master->ops = ops; master->match = match; component_master_debugfs_add(master); /* Add to the list of available masters. */ mutex_lock(&component_mutex); list_add(&master->node, &masters); ret = try_to_bring_up_master(master, NULL); if (ret < 0) free_master(master); mutex_unlock(&component_mutex); return ret < 0 ? ret : 0;}EXPORT_SYMBOL_GPL(component_master_add_with_match); /**Lines 1–500 of 776. Load more
// SPDX-License-Identifier: GPL-2.0 /* * Componentized device handling. * * This is work in progress. We gather up the component devices into a list, * and bind them when instructed. At the moment, we're specific to the DRM * subsystem, and only handles one master device, but this doesn't have to be * the case. */ #include <linux/component.h> #include <linux/device.h> #include <linux/kref.h> #include <linux/list.h> #include <linux/mutex.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 master { struct list_head node; bool bound; const struct component_master_ops *ops; struct device *dev; struct component_match *match; }; struct component { struct list_head node; struct master *master; 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(masters); #ifdef CONFIG_DEBUG_FS static struct dentry *component_debugfs_dir; static int component_devices_show(struct seq_file *s, void *data) { struct master *m = s->private; struct component_match *match = m->match; size_t i; mutex_lock(&component_mutex); seq_printf(s, "%-40s %20s\n", "master name", "status"); seq_puts(s, "-------------------------------------------------------------\n"); seq_printf(s, "%-40s %20s\n\n", dev_name(m->dev), m->bound ? "bound" : "not bound"); seq_printf(s, "%-40s %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, "%-40s %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_master_debugfs_add(struct master *m) { debugfs_create_file(dev_name(m->dev), 0444, component_debugfs_dir, m, &component_devices_fops); } static void component_master_debugfs_del(struct master *m) { debugfs_remove(debugfs_lookup(dev_name(m->dev), component_debugfs_dir)); } #else static void component_master_debugfs_add(struct master *m) { } static void component_master_debugfs_del(struct master *m) { } #endif static struct master *__master_find(struct device *dev, const struct component_master_ops *ops) { struct master *m; list_for_each_entry(m, &masters, node) if (m->dev == dev && (!ops || m->ops == ops)) return m; return NULL; } static struct component *find_component(struct master *master, struct component_match_array *mc) { struct component *c; list_for_each_entry(c, &component_list, node) { if (c->master && c->master != master) 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 master *master) { struct component_match *match = master->match; size_t i; int ret = 0; /* * Scan the array of match functions and attach * any components which are found to this master. */ for (i = 0; i < match->num; i++) { struct component_match_array *mc = &match->compare[i]; struct component *c; dev_dbg(master->dev, "Looking for component %zu\n", i); if (match->compare[i].component) continue; c = find_component(master, mc); if (!c) { ret = -ENXIO; break; } dev_dbg(master->dev, "found component %s, duplicate %u\n", dev_name(c->dev), !!c->master); /* Attach this component to the master */ match->compare[i].duplicate = !!c->master; match->compare[i].component = c; c->master = master; } return ret; } /* Detach component from associated master */ static void remove_component(struct master *master, struct component *c) { size_t i; /* Detach the component from this master. */ for (i = 0; i < master->match->num; i++) if (master->match->compare[i].component == c) master->match->compare[i].component = NULL; } /* * Try to bring up a master. If component is NULL, we're interested in * this master, otherwise it's a component which must be present to try * and bring up the master. * * Returns 1 for successful bringup, 0 if not ready, or -ve errno. */ static int try_to_bring_up_master(struct master *master, struct component *component) { int ret; dev_dbg(master->dev, "trying to bring up master\n"); if (find_components(master)) { dev_dbg(master->dev, "master has incomplete components\n"); return 0; } if (component && component->master != master) { dev_dbg(master->dev, "master is not for this component (%s)\n", dev_name(component->dev)); return 0; } if (!devres_open_group(master->dev, NULL, GFP_KERNEL)) return -ENOMEM; /* Found all components */ ret = master->ops->bind(master->dev); if (ret < 0) { devres_release_group(master->dev, NULL); if (ret != -EPROBE_DEFER) dev_info(master->dev, "master bind failed: %d\n", ret); return ret; } master->bound = true; return 1; } static int try_to_bring_up_masters(struct component *component) { struct master *m; int ret = 0; list_for_each_entry(m, &masters, node) { if (!m->bound) { ret = try_to_bring_up_master(m, component); if (ret != 0) break; } } return ret; } static void take_down_master(struct master *master) { if (master->bound) { master->ops->unbind(master->dev); devres_release_group(master->dev, NULL); master->bound = false; } } static void component_match_release(struct device *master, struct component_match *match) { unsigned int i; for (i = 0; i < match->num; i++) { struct component_match_array *mc = &match->compare[i]; if (mc->release) mc->release(master, mc->data); } kfree(match->compare); } static void devm_component_match_release(struct device *dev, void *res) { component_match_release(dev, res); } static int component_match_realloc(struct device *dev, struct component_match *match, size_t num) { struct component_match_array *new; if (match->alloc == num) return 0; new = kmalloc_array(num, sizeof(*new), GFP_KERNEL); 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 *master, 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(master, match); *matchptr = match; } if (match->num == match->alloc) { size_t new_size = match->alloc + 16; int ret; ret = component_match_realloc(master, 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 * @master: device with 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 @master * 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 *master, struct component_match **matchptr, void (*release)(struct device *, void *), int (*compare)(struct device *, void *), void *compare_data) { __component_match_add(master, 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 * @master: device with 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 @master * 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 *master, struct component_match **matchptr, int (*compare_typed)(struct device *, int, void *), void *compare_data) { __component_match_add(master, matchptr, NULL, NULL, compare_typed, compare_data); } EXPORT_SYMBOL(component_match_add_typed); static void free_master(struct master *master) { struct component_match *match = master->match; int i; component_master_debugfs_del(master); list_del(&master->node); if (match) { for (i = 0; i < match->num; i++) { struct component *c = match->compare[i].component; if (c) c->master = NULL; } } kfree(master); } /** * component_master_add_with_match - register an aggregate driver * @dev: device with 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 *dev, const struct component_master_ops *ops, struct component_match *match) { struct master *master; int ret; /* Reallocate the match array for its true size */ ret = component_match_realloc(dev, match, match->num); if (ret) return ret; master = kzalloc(sizeof(*master), GFP_KERNEL); if (!master) return -ENOMEM; master->dev = dev; master->ops = ops; master->match = match; component_master_debugfs_add(master); /* Add to the list of available masters. */ mutex_lock(&component_mutex); list_add(&master->node, &masters); ret = try_to_bring_up_master(master, NULL); if (ret < 0) free_master(master); mutex_unlock(&component_mutex); return ret < 0 ? ret : 0; } EXPORT_SYMBOL_GPL(component_master_add_with_match); /**