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author | Uwe Kleine-König <uwe@kleine-koenig.org> | 2021-12-22 09:13:37 +0100 |
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committer | Uwe Kleine-König <uwe@kleine-koenig.org> | 2021-12-22 09:13:37 +0100 |
commit | b8a660806fe0ee12070d1ef1fee7195972c977b8 (patch) | |
tree | a02b2ec2a6c706a2984db6cbf1be5eba05c1d063 | |
parent | 6c5656ee057080cc93d8ddc3a071d42c775a8cfa (diff) | |
download | linux-counter-dev-livetime.tar.gz linux-counter-dev-livetime.tar.xz |
-rw-r--r-- | drivers/counter/counter-core.c | 129 | ||||
-rw-r--r-- | include/linux/counter.h | 14 |
2 files changed, 142 insertions, 1 deletions
diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c index 224e2ad6319c..e68bd8d1124c 100644 --- a/drivers/counter/counter-core.c +++ b/drivers/counter/counter-core.c @@ -15,6 +15,7 @@ #include <linux/kdev_t.h> #include <linux/module.h> #include <linux/mutex.h> +#include <linux/slab.h> #include <linux/types.h> #include <linux/wait.h> @@ -24,13 +25,21 @@ /* Provides a unique ID for each counter device */ static DEFINE_IDA(counter_ida); +struct counter_device_allochelper { + struct counter_device counter; + unsigned long privdata[0]; +}; + static void counter_device_release(struct device *dev) { struct counter_device *const counter = - container_of(dev, struct struct counter_device, dev); + container_of(dev, struct counter_device, dev); counter_chrdev_remove(counter); ida_free(&counter_ida, dev->id); + + if (!counter->legacy_device) + kfree(container_of(counter, struct counter_device_allochelper, counter)); } static struct device_type counter_device_type = { @@ -62,6 +71,8 @@ int counter_register(struct counter_device *const counter) int id; int err; + counter->legacy_device = true; + /* Acquire unique ID */ id = ida_alloc(&counter_ida, GFP_KERNEL); if (id < 0) @@ -102,6 +113,110 @@ err_free_id: } EXPORT_SYMBOL_GPL(counter_register); +void *counter_priv(const struct counter_device *const counter) +{ + if (counter->legacy_device) { + return counter->priv; + } else { + struct counter_device_allochelper *ch = + container_of(counter, struct counter_device_allochelper, counter); + + return &ch->privdata; + } +} +EXPORT_SYMBOL_GPL(counter_priv); + +/** + * counter_alloc - allocate a counter_device + * @sizeof_priv: size of the driver private data + * + * This is part one of counter registration. The structure is allocated + * dynamically to ensure the right lifetime for the embedded struct device. + * + * If this succeeds, call counter_put() to get rid of the counter_device again. + */ +struct counter_device *counter_alloc(size_t sizeof_priv) +{ + struct counter_device_allochelper *ch; + struct counter_device *counter; + struct device *dev; + int id, err; + + ch = kzalloc(sizeof(*ch) + sizeof_priv, GFP_KERNEL); + if (!ch) { + err = -ENOMEM; + goto err_alloc_ch; + } + + counter = &ch->counter; + dev = &counter->dev; + + /* Acquire unique ID */ + err = ida_alloc(&counter_ida, GFP_KERNEL); + if (err < 0) { + goto err_ida_alloc; + } + dev->id = err; + + err = counter_chrdev_add(counter); + if (err < 0) + goto err_chrdev_add; + + device_initialize(dev); + /* Configure device structure for Counter */ + dev->type = &counter_device_type; + dev->bus = &counter_bus_type; + dev->devt = MKDEV(MAJOR(counter_devt), id); + + mutex_init(&counter->ops_exist_lock); + + return counter; + +err_chrdev_add: + + ida_free(&counter_ida, dev->id); +err_ida_alloc: + + kfree(ch); +err_alloc_ch: + + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(counter_alloc); + +void counter_put(struct counter_device *counter) +{ + put_device(&counter->dev); +} + +/** + * counter_add - complete registration of a counter + * @counter: the counter to add + * + * This is part two of counter registration. + * + * If this succeeds, call counter_unregister() to get rid of the counter_device again. + */ +int counter_add(struct counter_device *counter) +{ + int err; + struct device *dev = &counter->dev; + + if (counter->parent) { + dev->parent = counter->parent; + dev->of_node = counter->parent->of_node; + } + + err = counter_sysfs_add(counter); + if (err < 0) + return err; + + /* implies device_add(dev) */ + err = cdev_device_add(&counter->chrdev, dev); + + return err; +} + /** * counter_unregister - unregister Counter from the system * @counter: pointer to Counter to unregister @@ -156,6 +271,18 @@ int devm_counter_register(struct device *dev, } EXPORT_SYMBOL_GPL(devm_counter_register); +int devm_counter_add(struct device *dev, + struct counter_device *const counter) +{ + int err; + + err = counter_add(counter); + if (err < 0) + return err; + + return devm_add_action_or_reset(dev, devm_counter_release, counter); +} + #define COUNTER_DEV_MAX 256 static int __init counter_init(void) diff --git a/include/linux/counter.h b/include/linux/counter.h index b7d0a00a61cf..9a937dbd0eb0 100644 --- a/include/linux/counter.h +++ b/include/linux/counter.h @@ -327,12 +327,26 @@ struct counter_device { spinlock_t events_in_lock; struct mutex events_out_lock; struct mutex ops_exist_lock; + + /* + * This can go away once all drivers are converted to + * counter_alloc()/counter_add(). + */ + bool legacy_device; }; int counter_register(struct counter_device *const counter); + +void *counter_priv(const struct counter_device *const counter); +struct counter_device *counter_alloc(size_t sizeof_priv); +void counter_put(struct counter_device *const counter); +int counter_add(struct counter_device *const counter); + void counter_unregister(struct counter_device *const counter); int devm_counter_register(struct device *dev, struct counter_device *const counter); +int devm_counter_add(struct device *dev, + struct counter_device *const counter); void counter_push_event(struct counter_device *const counter, const u8 event, const u8 channel); |