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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
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| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /samples/configfs/configfs_sample.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'samples/configfs/configfs_sample.c')
| -rw-r--r-- | samples/configfs/configfs_sample.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/samples/configfs/configfs_sample.c b/samples/configfs/configfs_sample.c new file mode 100644 index 000000000..c1b108ec4 --- /dev/null +++ b/samples/configfs/configfs_sample.c @@ -0,0 +1,368 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * configfs_example_macros.c - This file is a demonstration module + * containing a number of configfs subsystems. It uses the helper + * macros defined by configfs.h + * + * Based on sysfs: + * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel + * + * configfs Copyright (C) 2005 Oracle. All rights reserved. + */ + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/configfs.h> + +/* + * 01-childless + * + * This first example is a childless subsystem. It cannot create + * any config_items. It just has attributes. + * + * Note that we are enclosing the configfs_subsystem inside a container. + * This is not necessary if a subsystem has no attributes directly + * on the subsystem. See the next example, 02-simple-children, for + * such a subsystem. + */ + +struct childless { + struct configfs_subsystem subsys; + int showme; + int storeme; +}; + +static inline struct childless *to_childless(struct config_item *item) +{ + return container_of(to_configfs_subsystem(to_config_group(item)), + struct childless, subsys); +} + +static ssize_t childless_showme_show(struct config_item *item, char *page) +{ + struct childless *childless = to_childless(item); + ssize_t pos; + + pos = sprintf(page, "%d\n", childless->showme); + childless->showme++; + + return pos; +} + +static ssize_t childless_storeme_show(struct config_item *item, char *page) +{ + return sprintf(page, "%d\n", to_childless(item)->storeme); +} + +static ssize_t childless_storeme_store(struct config_item *item, + const char *page, size_t count) +{ + struct childless *childless = to_childless(item); + int ret; + + ret = kstrtoint(page, 10, &childless->storeme); + if (ret) + return ret; + + return count; +} + +static ssize_t childless_description_show(struct config_item *item, char *page) +{ + return sprintf(page, +"[01-childless]\n" +"\n" +"The childless subsystem is the simplest possible subsystem in\n" +"configfs. It does not support the creation of child config_items.\n" +"It only has a few attributes. In fact, it isn't much different\n" +"than a directory in /proc.\n"); +} + +CONFIGFS_ATTR_RO(childless_, showme); +CONFIGFS_ATTR(childless_, storeme); +CONFIGFS_ATTR_RO(childless_, description); + +static struct configfs_attribute *childless_attrs[] = { + &childless_attr_showme, + &childless_attr_storeme, + &childless_attr_description, + NULL, +}; + +static const struct config_item_type childless_type = { + .ct_attrs = childless_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct childless childless_subsys = { + .subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "01-childless", + .ci_type = &childless_type, + }, + }, + }, +}; + +/* ----------------------------------------------------------------- */ + +/* + * 02-simple-children + * + * This example merely has a simple one-attribute child. Note that + * there is no extra attribute structure, as the child's attribute is + * known from the get-go. Also, there is no container for the + * subsystem, as it has no attributes of its own. + */ + +struct simple_child { + struct config_item item; + int storeme; +}; + +static inline struct simple_child *to_simple_child(struct config_item *item) +{ + return container_of(item, struct simple_child, item); +} + +static ssize_t simple_child_storeme_show(struct config_item *item, char *page) +{ + return sprintf(page, "%d\n", to_simple_child(item)->storeme); +} + +static ssize_t simple_child_storeme_store(struct config_item *item, + const char *page, size_t count) +{ + struct simple_child *simple_child = to_simple_child(item); + int ret; + + ret = kstrtoint(page, 10, &simple_child->storeme); + if (ret) + return ret; + + return count; +} + +CONFIGFS_ATTR(simple_child_, storeme); + +static struct configfs_attribute *simple_child_attrs[] = { + &simple_child_attr_storeme, + NULL, +}; + +static void simple_child_release(struct config_item *item) +{ + kfree(to_simple_child(item)); +} + +static const struct configfs_item_operations simple_child_item_ops = { + .release = simple_child_release, +}; + +static const struct config_item_type simple_child_type = { + .ct_item_ops = &simple_child_item_ops, + .ct_attrs = simple_child_attrs, + .ct_owner = THIS_MODULE, +}; + +struct simple_children { + struct config_group group; +}; + +static inline struct simple_children *to_simple_children(struct config_item *item) +{ + return container_of(to_config_group(item), + struct simple_children, group); +} + +static struct config_item *simple_children_make_item(struct config_group *group, + const char *name) +{ + struct simple_child *simple_child; + + simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL); + if (!simple_child) + return ERR_PTR(-ENOMEM); + + config_item_init_type_name(&simple_child->item, name, + &simple_child_type); + + return &simple_child->item; +} + +static ssize_t simple_children_description_show(struct config_item *item, + char *page) +{ + return sprintf(page, +"[02-simple-children]\n" +"\n" +"This subsystem allows the creation of child config_items. These\n" +"items have only one attribute that is readable and writeable.\n"); +} + +CONFIGFS_ATTR_RO(simple_children_, description); + +static struct configfs_attribute *simple_children_attrs[] = { + &simple_children_attr_description, + NULL, +}; + +static void simple_children_release(struct config_item *item) +{ + kfree(to_simple_children(item)); +} + +static const struct configfs_item_operations simple_children_item_ops = { + .release = simple_children_release, +}; + +/* + * Note that, since no extra work is required on ->drop_item(), + * no ->drop_item() is provided. + */ +static const struct configfs_group_operations simple_children_group_ops = { + .make_item = simple_children_make_item, +}; + +static const struct config_item_type simple_children_type = { + .ct_item_ops = &simple_children_item_ops, + .ct_group_ops = &simple_children_group_ops, + .ct_attrs = simple_children_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem simple_children_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "02-simple-children", + .ci_type = &simple_children_type, + }, + }, +}; + +/* ----------------------------------------------------------------- */ + +/* + * 03-group-children + * + * This example reuses the simple_children group from above. However, + * the simple_children group is not the subsystem itself, it is a + * child of the subsystem. Creation of a group in the subsystem creates + * a new simple_children group. That group can then have simple_child + * children of its own. + */ + +static struct config_group *group_children_make_group( + struct config_group *group, const char *name) +{ + struct simple_children *simple_children; + + simple_children = kzalloc(sizeof(struct simple_children), + GFP_KERNEL); + if (!simple_children) + return ERR_PTR(-ENOMEM); + + config_group_init_type_name(&simple_children->group, name, + &simple_children_type); + + return &simple_children->group; +} + +static ssize_t group_children_description_show(struct config_item *item, + char *page) +{ + return sprintf(page, +"[03-group-children]\n" +"\n" +"This subsystem allows the creation of child config_groups. These\n" +"groups are like the subsystem simple-children.\n"); +} + +CONFIGFS_ATTR_RO(group_children_, description); + +static struct configfs_attribute *group_children_attrs[] = { + &group_children_attr_description, + NULL, +}; + +/* + * Note that, since no extra work is required on ->drop_item(), + * no ->drop_item() is provided. + */ +static const struct configfs_group_operations group_children_group_ops = { + .make_group = group_children_make_group, +}; + +static const struct config_item_type group_children_type = { + .ct_group_ops = &group_children_group_ops, + .ct_attrs = group_children_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem group_children_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "03-group-children", + .ci_type = &group_children_type, + }, + }, +}; + +/* ----------------------------------------------------------------- */ + +/* + * We're now done with our subsystem definitions. + * For convenience in this module, here's a list of them all. It + * allows the init function to easily register them. Most modules + * will only have one subsystem, and will only call register_subsystem + * on it directly. + */ +static struct configfs_subsystem *example_subsys[] = { + &childless_subsys.subsys, + &simple_children_subsys, + &group_children_subsys, + NULL, +}; + +static int __init configfs_example_init(void) +{ + struct configfs_subsystem *subsys; + int ret, i; + + for (i = 0; example_subsys[i]; i++) { + subsys = example_subsys[i]; + + config_group_init(&subsys->su_group); + mutex_init(&subsys->su_mutex); + ret = configfs_register_subsystem(subsys); + if (ret) { + pr_err("Error %d while registering subsystem %s\n", + ret, subsys->su_group.cg_item.ci_namebuf); + goto out_unregister; + } + } + + return 0; + +out_unregister: + for (i--; i >= 0; i--) + configfs_unregister_subsystem(example_subsys[i]); + + return ret; +} + +static void __exit configfs_example_exit(void) +{ + int i; + + for (i = 0; example_subsys[i]; i++) + configfs_unregister_subsystem(example_subsys[i]); +} + +module_init(configfs_example_init); +module_exit(configfs_example_exit); +MODULE_DESCRIPTION("Sample configfs module"); +MODULE_LICENSE("GPL"); |
