This patch introduces a character device interface for the Counter subsystem. Device data is exposed through standard character device read operations. Device data is gathered when a Counter event is pushed by the respective Counter device driver. Configuration is handled via ioctl operations on the respective Counter character device node.
Cc: David Lechner <[email protected]> Cc: Gwendal Grignou <[email protected]> Cc: Dan Carpenter <[email protected]> Signed-off-by: William Breathitt Gray <[email protected]> --- MAINTAINERS | 1 + drivers/counter/Makefile | 2 +- drivers/counter/counter-chrdev.c | 476 +++++++++++++++++++++++++++++++ drivers/counter/counter-chrdev.h | 16 ++ drivers/counter/counter-core.c | 38 ++- drivers/counter/counter-sysfs.c | 51 +++- include/linux/counter.h | 66 +++-- include/uapi/linux/counter.h | 105 +++++++ 8 files changed, 711 insertions(+), 44 deletions(-) create mode 100644 drivers/counter/counter-chrdev.c create mode 100644 drivers/counter/counter-chrdev.h create mode 100644 include/uapi/linux/counter.h diff --git a/MAINTAINERS b/MAINTAINERS index 5e0d8ca70912..beda3366b64c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4453,6 +4453,7 @@ F: Documentation/ABI/testing/sysfs-bus-counter* F: Documentation/driver-api/generic-counter.rst F: drivers/counter/ F: include/linux/counter.h +F: include/uapi/linux/counter.h CPMAC ETHERNET DRIVER M: Florian Fainelli <[email protected]> diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile index cbe1d06af6a9..c4870eb5b1dd 100644 --- a/drivers/counter/Makefile +++ b/drivers/counter/Makefile @@ -4,7 +4,7 @@ # obj-$(CONFIG_COUNTER) += counter.o -counter-y := counter-core.o counter-sysfs.o +counter-y := counter-core.o counter-sysfs.o counter-chrdev.o obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o obj-$(CONFIG_STM32_TIMER_CNT) += stm32-timer-cnt.o diff --git a/drivers/counter/counter-chrdev.c b/drivers/counter/counter-chrdev.c new file mode 100644 index 000000000000..96fa7fbeef92 --- /dev/null +++ b/drivers/counter/counter-chrdev.c @@ -0,0 +1,476 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Generic Counter character device interface + * Copyright (C) 2020 William Breathitt Gray + */ + +#include <linux/cdev.h> +#include <linux/counter.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/export.h> +#include <linux/fs.h> +#include <linux/list.h> +#include <linux/nospec.h> +#include <linux/poll.h> +#include <linux/kdev_t.h> +#include <linux/kfifo.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/timekeeping.h> +#include <linux/types.h> +#include <linux/wait.h> +#include <linux/uaccess.h> + +#include "counter-chrdev.h" + +struct counter_comp_node { + struct list_head l; + struct counter_component component; + struct counter_comp comp; + void *parent; +}; + +static ssize_t counter_chrdev_read(struct file *filp, char __user *buf, + size_t len, loff_t *f_ps) +{ + struct counter_device *const counter = filp->private_data; + int err; + unsigned long flags; + unsigned int copied; + + if (len < sizeof(struct counter_event)) + return -EINVAL; + + do { + if (kfifo_is_empty(&counter->events)) { + if (filp->f_flags & O_NONBLOCK) + return -EAGAIN; + + err = wait_event_interruptible(counter->events_wait, + !kfifo_is_empty(&counter->events)); + if (err) + return err; + } + + raw_spin_lock_irqsave(&counter->events_lock, flags); + err = kfifo_to_user(&counter->events, buf, len, &copied); + raw_spin_unlock_irqrestore(&counter->events_lock, flags); + if (err) + return err; + } while (!copied); + + return copied; +} + +static __poll_t counter_chrdev_poll(struct file *filp, + struct poll_table_struct *pollt) +{ + struct counter_device *const counter = filp->private_data; + __poll_t events = 0; + + poll_wait(filp, &counter->events_wait, pollt); + + if (!kfifo_is_empty(&counter->events)) + events = EPOLLIN | EPOLLRDNORM; + + return events; +} + +static void counter_events_list_free(struct list_head *const events_list) +{ + struct counter_event_node *p, *n; + struct counter_comp_node *q, *o; + + list_for_each_entry_safe(p, n, events_list, l) { + /* Free associated component nodes */ + list_for_each_entry_safe(q, o, &p->comp_list, l) { + list_del(&q->l); + kfree(q); + } + + /* Free event node */ + list_del(&p->l); + kfree(p); + } +} + +static int counter_set_event_node(struct counter_device *const counter, + struct counter_watch *const watch, + const struct counter_comp_node *const cfg) +{ + struct counter_event_node *event_node; + struct counter_comp_node *comp_node; + + /* Search for event in the list */ + list_for_each_entry(event_node, &counter->next_events_list, l) + if (event_node->event == watch->event && + event_node->channel == watch->channel) + break; + + /* If event is not already in the list */ + if (&event_node->l == &counter->next_events_list) { + /* Allocate new event node */ + event_node = kmalloc(sizeof(*event_node), GFP_ATOMIC); + if (!event_node) + return -ENOMEM; + + /* Configure event node and add to the list */ + event_node->event = watch->event; + event_node->channel = watch->channel; + INIT_LIST_HEAD(&event_node->comp_list); + list_add(&event_node->l, &counter->next_events_list); + } + + /* Check if component watch has already been set before */ + list_for_each_entry(comp_node, &event_node->comp_list, l) + if (comp_node->parent == cfg->parent && + comp_node->comp.count_u8_read == cfg->comp.count_u8_read) + return -EINVAL; + + /* Allocate component node */ + comp_node = kmalloc(sizeof(*comp_node), GFP_ATOMIC); + if (!comp_node) { + /* Free event node if no one else is watching */ + if (list_empty(&event_node->comp_list)) { + list_del(&event_node->l); + kfree(event_node); + } + return -ENOMEM; + } + *comp_node = *cfg; + + /* Add component node to event node */ + list_add_tail(&comp_node->l, &event_node->comp_list); + + return 0; +} + +static int counter_add_watch(struct counter_device *const counter, + const unsigned long arg) +{ + void __user *const uwatch = (void __user *)arg; + struct counter_watch watch; + struct counter_comp_node comp_node = {0}; + size_t parent, id; + struct counter_comp *ext; + size_t num_ext; + + if (copy_from_user(&watch, uwatch, sizeof(watch))) + return -EFAULT; + + /* Dummy components can skip evaluation */ + if (watch.component.type == COUNTER_COMPONENT_DUMMY) + goto dummy_component; + + parent = watch.component.parent; + + /* Configure parent component info for comp node */ + switch (watch.component.scope) { + case COUNTER_SCOPE_DEVICE: + ext = counter->ext; + num_ext = counter->num_ext; + break; + case COUNTER_SCOPE_SIGNAL: + if (parent >= counter->num_signals) + return -EINVAL; + parent = array_index_nospec(parent, counter->num_signals); + + comp_node.parent = counter->signals + parent; + + ext = counter->signals[parent].ext; + num_ext = counter->signals[parent].num_ext; + break; + case COUNTER_SCOPE_COUNT: + if (parent >= counter->num_counts) + return -EINVAL; + parent = array_index_nospec(parent, counter->num_counts); + + comp_node.parent = counter->counts + parent; + + ext = counter->counts[parent].ext; + num_ext = counter->counts[parent].num_ext; + break; + default: + return -EINVAL; + } + + id = watch.component.id; + + /* Configure component info for comp node */ + switch (watch.component.type) { + case COUNTER_COMPONENT_SIGNAL: + if (watch.component.scope != COUNTER_SCOPE_SIGNAL) + return -EINVAL; + + comp_node.comp.type = COUNTER_COMP_SIGNAL_LEVEL; + comp_node.comp.signal_u8_read = counter->ops->signal_read; + break; + case COUNTER_COMPONENT_COUNT: + if (watch.component.scope != COUNTER_SCOPE_COUNT) + return -EINVAL; + + comp_node.comp.type = COUNTER_COMP_U64; + comp_node.comp.count_u64_read = counter->ops->count_read; + break; + case COUNTER_COMPONENT_FUNCTION: + if (watch.component.scope != COUNTER_SCOPE_COUNT) + return -EINVAL; + + comp_node.comp.type = COUNTER_COMP_FUNCTION; + comp_node.comp.count_u8_read = counter->ops->function_read; + break; + case COUNTER_COMPONENT_SYNAPSE_ACTION: + if (watch.component.scope != COUNTER_SCOPE_COUNT) + return -EINVAL; + if (id >= counter->counts[parent].num_synapses) + return -EINVAL; + id = array_index_nospec(id, counter->counts[parent].num_synapses); + + comp_node.comp.type = COUNTER_COMP_SYNAPSE_ACTION; + comp_node.comp.action_read = counter->ops->action_read; + comp_node.comp.priv = counter->counts[parent].synapses + id; + break; + case COUNTER_COMPONENT_EXTENSION: + if (id >= num_ext) + return -EINVAL; + id = array_index_nospec(id, num_ext); + + comp_node.comp = ext[id]; + break; + default: + return -EINVAL; + } + /* Check if any read callback is set; this is part of a union */ + if (!comp_node.comp.count_u8_read) + return -EOPNOTSUPP; + +dummy_component: + comp_node.component = watch.component; + + return counter_set_event_node(counter, &watch, &comp_node); +} + +static long counter_chrdev_ioctl(struct file *filp, unsigned int cmd, + unsigned long arg) +{ + struct counter_device *const counter = filp->private_data; + raw_spinlock_t *const events_lock = &counter->events_lock; + unsigned long flags; + struct list_head *const events_list = &counter->events_list; + struct list_head *const next_events_list = &counter->next_events_list; + int err = 0; + + switch (cmd) { + case COUNTER_CLEAR_WATCHES_IOCTL: + raw_spin_lock_irqsave(events_lock, flags); + + counter_events_list_free(events_list); + + if (counter->ops->events_config) + err = counter->ops->events_config(counter); + + raw_spin_unlock_irqrestore(events_lock, flags); + + counter_events_list_free(next_events_list); + break; + case COUNTER_ADD_WATCH_IOCTL: + return counter_add_watch(counter, arg); + case COUNTER_LOAD_WATCHES_IOCTL: + raw_spin_lock_irqsave(events_lock, flags); + + counter_events_list_free(events_list); + list_replace_init(next_events_list, events_list); + + if (counter->ops->events_config) + err = counter->ops->events_config(counter); + + raw_spin_unlock_irqrestore(events_lock, flags); + break; + default: + return -ENOIOCTLCMD; + } + + return err; +} + +static int counter_chrdev_open(struct inode *inode, struct file *filp) +{ + struct counter_device *const counter = container_of(inode->i_cdev, + typeof(*counter), + chrdev); + + get_device(&counter->dev); + filp->private_data = counter; + + return nonseekable_open(inode, filp); +} + +static int counter_chrdev_release(struct inode *inode, struct file *filp) +{ + struct counter_device *const counter = filp->private_data; + unsigned long flags; + + raw_spin_lock_irqsave(&counter->events_lock, flags); + counter_events_list_free(&counter->events_list); + raw_spin_unlock_irqrestore(&counter->events_lock, flags); + counter_events_list_free(&counter->next_events_list); + + put_device(&counter->dev); + + return 0; +} + +static const struct file_operations counter_fops = { + .llseek = no_llseek, + .read = counter_chrdev_read, + .poll = counter_chrdev_poll, + .unlocked_ioctl = counter_chrdev_ioctl, + .open = counter_chrdev_open, + .release = counter_chrdev_release, +}; + +int counter_chrdev_add(struct counter_device *const counter, + const dev_t counter_devt) +{ + struct device *const dev = &counter->dev; + struct cdev *const chrdev = &counter->chrdev; + + /* Initialize Counter events lists */ + INIT_LIST_HEAD(&counter->events_list); + INIT_LIST_HEAD(&counter->next_events_list); + raw_spin_lock_init(&counter->events_lock); + + /* Initialize Counter events queue */ + INIT_KFIFO(counter->events); + init_waitqueue_head(&counter->events_wait); + + /* Initialize character device */ + cdev_init(chrdev, &counter_fops); + dev->devt = MKDEV(MAJOR(counter_devt), counter->id); + cdev_set_parent(chrdev, &dev->kobj); + + return cdev_add(chrdev, dev->devt, 1); +} + +void counter_chrdev_remove(struct counter_device *const counter) +{ + cdev_del(&counter->chrdev); +} + +static int counter_get_data(struct counter_device *const counter, + const struct counter_comp_node *const comp_node, + u64 *const value) +{ + const struct counter_comp *const comp = &comp_node->comp; + void *const parent = comp_node->parent; + int err = 0; + u8 value_u8; + + /* Dummy components don't have data so return early */ + if (comp_node->component.type == COUNTER_COMPONENT_DUMMY) + return 0; + + switch (comp->type) { + case COUNTER_COMP_U8: + case COUNTER_COMP_BOOL: + case COUNTER_COMP_SIGNAL_LEVEL: + case COUNTER_COMP_FUNCTION: + case COUNTER_COMP_ENUM: + case COUNTER_COMP_COUNT_DIRECTION: + case COUNTER_COMP_COUNT_MODE: + switch (comp_node->component.scope) { + case COUNTER_SCOPE_DEVICE: + err = comp->device_u8_read(counter, &value_u8); + break; + case COUNTER_SCOPE_SIGNAL: + err = comp->signal_u8_read(counter, parent, &value_u8); + break; + case COUNTER_SCOPE_COUNT: + err = comp->count_u8_read(counter, parent, &value_u8); + break; + } + if (err) + return err; + *value = value_u8; + break; + case COUNTER_COMP_U64: + switch (comp_node->component.scope) { + case COUNTER_SCOPE_DEVICE: + return comp->device_u64_read(counter, value); + case COUNTER_SCOPE_SIGNAL: + return comp->signal_u64_read(counter, parent, value); + case COUNTER_SCOPE_COUNT: + return comp->count_u64_read(counter, parent, value); + } + break; + case COUNTER_COMP_SYNAPSE_ACTION: + err = comp->action_read(counter, parent, comp->priv, &value_u8); + if (err) + return err; + *value = value_u8; + break; + } + + return 0; +} + +/** + * counter_push_event - queue event for userspace reading + * @counter: pointer to Counter structure + * @event: triggered event + * @channel: event channel + * + * Note: If no one is watching for the respective event, it is silently + * discarded. + * + * RETURNS: + * 0 on success, negative error number on failure. + */ +int counter_push_event(struct counter_device *const counter, const u8 event, + const u8 channel) +{ + struct counter_event ev = {0}; + unsigned int copied = 0; + unsigned long flags; + struct counter_event_node *event_node; + struct counter_comp_node *comp_node; + int err = 0; + + ev.timestamp = ktime_get_ns(); + ev.watch.event = event; + ev.watch.channel = channel; + + raw_spin_lock_irqsave(&counter->events_lock, flags); + + /* Search for event in the list */ + list_for_each_entry(event_node, &counter->events_list, l) + if (event_node->event == event && + event_node->channel == channel) + break; + + /* If event is not in the list */ + if (&event_node->l == &counter->events_list) + goto exit_early; + + /* Read and queue relevant comp for userspace */ + list_for_each_entry(comp_node, &event_node->comp_list, l) { + err = counter_get_data(counter, comp_node, &ev.value); + if (err) + goto exit_early; + + ev.watch.component = comp_node->component; + + copied += kfifo_put(&counter->events, ev); + } + + if (copied) + wake_up_poll(&counter->events_wait, EPOLLIN); + +exit_early: + raw_spin_unlock_irqrestore(&counter->events_lock, flags); + + return err; +} +EXPORT_SYMBOL_GPL(counter_push_event); diff --git a/drivers/counter/counter-chrdev.h b/drivers/counter/counter-chrdev.h new file mode 100644 index 000000000000..cf5a318fe540 --- /dev/null +++ b/drivers/counter/counter-chrdev.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Counter character device interface + * Copyright (C) 2020 William Breathitt Gray + */ +#ifndef _COUNTER_CHRDEV_H_ +#define _COUNTER_CHRDEV_H_ + +#include <linux/counter.h> +#include <linux/types.h> + +int counter_chrdev_add(struct counter_device *const counter, + const dev_t counter_devt); +void counter_chrdev_remove(struct counter_device *const counter); + +#endif /* _COUNTER_CHRDEV_H_ */ diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c index 251627b95a3a..088886e93898 100644 --- a/drivers/counter/counter-core.c +++ b/drivers/counter/counter-core.c @@ -5,12 +5,16 @@ */ #include <linux/counter.h> #include <linux/device.h> +#include <linux/device/bus.h> #include <linux/export.h> +#include <linux/fs.h> #include <linux/gfp.h> #include <linux/idr.h> #include <linux/init.h> #include <linux/module.h> +#include <linux/types.h> +#include "counter-chrdev.h" #include "counter-sysfs.h" /* Provides a unique ID for each counter device */ @@ -33,6 +37,8 @@ static struct bus_type counter_bus_type = { .name = "counter" }; +static dev_t counter_devt; + /** * counter_register - register Counter to the system * @counter: pointer to Counter to register @@ -51,7 +57,6 @@ int counter_register(struct counter_device *const counter) if (counter->id < 0) return counter->id; - /* Configure device structure for Counter */ dev->type = &counter_device_type; dev->bus = &counter_bus_type; if (counter->parent) { @@ -62,18 +67,25 @@ int counter_register(struct counter_device *const counter) device_initialize(dev); dev_set_drvdata(dev, counter); + /* Add Counter character device */ + err = counter_chrdev_add(counter, counter_devt); + if (err) + goto err_free_id; + /* Add Counter sysfs attributes */ err = counter_sysfs_add(counter); if (err) - goto err_free_id; + goto err_remove_chrdev; /* Add device to system */ err = device_add(dev); if (err) - goto err_free_id; + goto err_remove_chrdev; return 0; +err_remove_chrdev: + counter_chrdev_remove(counter); err_free_id: put_device(dev); return err; @@ -92,6 +104,7 @@ void counter_unregister(struct counter_device *const counter) return; device_unregister(&counter->dev); + counter_chrdev_remove(counter); } EXPORT_SYMBOL_GPL(counter_unregister); @@ -135,13 +148,30 @@ int devm_counter_register(struct device *dev, } EXPORT_SYMBOL_GPL(devm_counter_register); +#define COUNTER_DEV_MAX 256 + static int __init counter_init(void) { - return bus_register(&counter_bus_type); + int err; + + err = bus_register(&counter_bus_type); + if (err < 0) + return err; + + err = alloc_chrdev_region(&counter_devt, 0, COUNTER_DEV_MAX, "counter"); + if (err < 0) + goto err_unregister_bus; + + return 0; + +err_unregister_bus: + bus_unregister(&counter_bus_type); + return err; } static void __exit counter_exit(void) { + unregister_chrdev_region(counter_devt, COUNTER_DEV_MAX); bus_unregister(&counter_bus_type); } diff --git a/drivers/counter/counter-sysfs.c b/drivers/counter/counter-sysfs.c index c767754d0310..7b677c7de251 100644 --- a/drivers/counter/counter-sysfs.c +++ b/drivers/counter/counter-sysfs.c @@ -437,6 +437,7 @@ static ssize_t counter_comp_name_show(struct device *dev, static int counter_name_attr_create(struct device *const dev, struct counter_attribute_group *const group, + const char *const attr_name, const char *const name) { struct counter_attribute *counter_attr; @@ -451,7 +452,7 @@ static int counter_name_attr_create(struct device *const dev, /* Configure device attribute */ sysfs_attr_init(&counter_attr->dev_attr.attr); - counter_attr->dev_attr.attr.name = "name"; + counter_attr->dev_attr.attr.name = attr_name; counter_attr->dev_attr.attr.mode = 0444; counter_attr->dev_attr.show = counter_comp_name_show; @@ -462,6 +463,18 @@ static int counter_name_attr_create(struct device *const dev, return 0; } +static int counter_ext_name_attr_create(struct device *const dev, + struct counter_attribute_group *const group, const size_t i, + const char *const name) +{ + const char *attr_name; + + attr_name = devm_kasprintf(dev, GFP_KERNEL, "extension%zu_name", i); + if (!attr_name) + return -ENOMEM; + + return counter_name_attr_create(dev, group, attr_name, name); +} static struct counter_comp counter_signal_comp = { .type = COUNTER_COMP_SIGNAL_LEVEL, @@ -477,6 +490,7 @@ static int counter_signal_attrs_create(struct counter_device *const counter, int err; struct counter_comp comp; size_t i; + struct counter_comp *ext; /* Create main Signal attribute */ comp = counter_signal_comp; @@ -486,14 +500,19 @@ static int counter_signal_attrs_create(struct counter_device *const counter, return err; /* Create Signal name attribute */ - err = counter_name_attr_create(dev, group, signal->name); + err = counter_name_attr_create(dev, group, "name", signal->name); if (err) return err; /* Create an attribute for each extension */ for (i = 0; i < signal->num_ext; i++) { - err = counter_attr_create(dev, group, signal->ext + i, scope, - signal); + ext = signal->ext + i; + + err = counter_attr_create(dev, group, ext, scope, signal); + if (err) + return err; + + err = counter_ext_name_attr_create(dev, group, i, ext->name); if (err) return err; } @@ -578,6 +597,7 @@ static int counter_count_attrs_create(struct counter_device *const counter, int err; struct counter_comp comp; size_t i; + struct counter_comp *ext; /* Create main Count attribute */ comp = counter_count_comp; @@ -588,7 +608,7 @@ static int counter_count_attrs_create(struct counter_device *const counter, return err; /* Create Count name attribute */ - err = counter_name_attr_create(dev, group, count->name); + err = counter_name_attr_create(dev, group, "name", count->name); if (err) return err; @@ -602,8 +622,13 @@ static int counter_count_attrs_create(struct counter_device *const counter, /* Create an attribute for each extension */ for (i = 0; i < count->num_ext; i++) { - err = counter_attr_create(dev, group, count->ext + i, scope, - count); + ext = count->ext + i; + + err = counter_attr_create(dev, group, ext, scope, count); + if (err) + return err; + + err = counter_ext_name_attr_create(dev, group, i, ext->name); if (err) return err; } @@ -667,6 +692,7 @@ static int counter_sysfs_attr_add(struct counter_device *const counter, struct device *const dev = &counter->dev; int err; size_t i; + struct counter_comp *ext; /* Add Signals sysfs attributes */ err = counter_sysfs_signals_add(counter, group); @@ -681,7 +707,7 @@ static int counter_sysfs_attr_add(struct counter_device *const counter, group += counter->num_counts; /* Create name attribute */ - err = counter_name_attr_create(dev, group, counter->name); + err = counter_name_attr_create(dev, group, "name", counter->name); if (err) return err; @@ -699,8 +725,13 @@ static int counter_sysfs_attr_add(struct counter_device *const counter, /* Create an attribute for each extension */ for (i = 0; i < counter->num_ext; i++) { - err = counter_attr_create(dev, group, counter->ext + i, scope, - NULL); + ext = counter->ext + i; + + err = counter_attr_create(dev, group, ext, scope, NULL); + if (err) + return err; + + err = counter_ext_name_attr_create(dev, group, i, ext->name); if (err) return err; } diff --git a/include/linux/counter.h b/include/linux/counter.h index 3f3f8ba6c1b4..98cd7c035968 100644 --- a/include/linux/counter.h +++ b/include/linux/counter.h @@ -6,9 +6,14 @@ #ifndef _COUNTER_H_ #define _COUNTER_H_ +#include <linux/cdev.h> #include <linux/device.h> #include <linux/kernel.h> +#include <linux/kfifo.h> +#include <linux/spinlock_types.h> #include <linux/types.h> +#include <linux/wait.h> +#include <uapi/linux/counter.h> struct counter_device; struct counter_count; @@ -27,35 +32,6 @@ enum counter_comp_type { COUNTER_COMP_COUNT_MODE, }; -#define COUNTER_SCOPE_DEVICE 0 -#define COUNTER_SCOPE_SIGNAL 1 -#define COUNTER_SCOPE_COUNT 2 - -#define COUNTER_COUNT_DIRECTION_FORWARD 0 -#define COUNTER_COUNT_DIRECTION_BACKWARD 1 - -#define COUNTER_COUNT_MODE_NORMAL 0 -#define COUNTER_COUNT_MODE_RANGE_LIMIT 1 -#define COUNTER_COUNT_MODE_NON_RECYCLE 2 -#define COUNTER_COUNT_MODE_MODULO_N 3 - -#define COUNTER_FUNCTION_INCREASE 0 -#define COUNTER_FUNCTION_DECREASE 1 -#define COUNTER_FUNCTION_PULSE_DIRECTION 2 -#define COUNTER_FUNCTION_QUADRATURE_X1_A 3 -#define COUNTER_FUNCTION_QUADRATURE_X1_B 4 -#define COUNTER_FUNCTION_QUADRATURE_X2_A 5 -#define COUNTER_FUNCTION_QUADRATURE_X2_B 6 -#define COUNTER_FUNCTION_QUADRATURE_X4 7 - -#define COUNTER_SIGNAL_LEVEL_LOW 0 -#define COUNTER_SIGNAL_LEVEL_HIGH 1 - -#define COUNTER_SYNAPSE_ACTION_NONE 0 -#define COUNTER_SYNAPSE_ACTION_RISING_EDGE 1 -#define COUNTER_SYNAPSE_ACTION_FALLING_EDGE 2 -#define COUNTER_SYNAPSE_ACTION_BOTH_EDGES 3 - /** * struct counter_comp - Counter component node * @type: Counter component data type @@ -195,6 +171,20 @@ struct counter_count { size_t num_ext; }; +/** + * struct counter_event_node - Counter Event node + * @l: list of current watching Counter events + * @event: event that triggers + * @channel: event channel + * @comp_list: list of components to watch when event triggers + */ +struct counter_event_node { + struct list_head l; + u8 event; + u8 channel; + struct list_head comp_list; +}; + /** * struct counter_ops - Callbacks from driver * @signal_read: read callback for Signals. The read value of the @@ -217,6 +207,9 @@ struct counter_count { * @action_write: write callback for Synapse action modes. The action mode * to write for the respective Synapse is passed in via the * action parameter. + * @events_config: write callback to configure events. The list of struct + * counter_event_node may be accessed via the events_list + * member of the counter parameter. */ struct counter_ops { int (*signal_read)(struct counter_device *counter, @@ -235,6 +228,7 @@ struct counter_ops { int (*action_write)(struct counter_device *counter, struct counter_count *count, struct counter_synapse *synapse, u8 action); + int (*events_config)(struct counter_device *counter); }; /** @@ -251,6 +245,12 @@ struct counter_ops { * @priv: optional private data supplied by driver * @id: unique ID used to identify the Counter * @dev: internal device structure + * @chrdev: internal character device structure + * @events_lock: synchronization lock for Counter events + * @events_list: list of current watching Counter events + * @next_events_list: list of next watching Counter events + * @events: queue of detected Counter events + * @events_wait: wait queue to allow blocking reads of Counter events */ struct counter_device { const char *name; @@ -270,12 +270,20 @@ struct counter_device { int id; struct device dev; + struct cdev chrdev; + raw_spinlock_t events_lock; + struct list_head events_list; + struct list_head next_events_list; + DECLARE_KFIFO(events, struct counter_event, 64); + wait_queue_head_t events_wait; }; int counter_register(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 counter_push_event(struct counter_device *const counter, const u8 event, + const u8 channel); #define COUNTER_COMP_DEVICE_U8(_name, _read, _write) \ { \ diff --git a/include/uapi/linux/counter.h b/include/uapi/linux/counter.h new file mode 100644 index 000000000000..0a3a412c7061 --- /dev/null +++ b/include/uapi/linux/counter.h @@ -0,0 +1,105 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * Userspace ABI for Counter character devices + * Copyright (C) 2020 William Breathitt Gray + */ +#ifndef _UAPI_COUNTER_H_ +#define _UAPI_COUNTER_H_ + +#include <linux/ioctl.h> +#include <linux/types.h> + +/* Component type definitions */ +#define COUNTER_COMPONENT_DUMMY 0 +#define COUNTER_COMPONENT_SIGNAL 1 +#define COUNTER_COMPONENT_COUNT 2 +#define COUNTER_COMPONENT_FUNCTION 3 +#define COUNTER_COMPONENT_SYNAPSE_ACTION 4 +#define COUNTER_COMPONENT_EXTENSION 5 + +/* Component scope definitions */ +#define COUNTER_SCOPE_DEVICE 0 +#define COUNTER_SCOPE_SIGNAL 1 +#define COUNTER_SCOPE_COUNT 2 + +/** + * struct counter_component - Counter component identification + * @type: component type (Count, extension, etc.) + * @scope: component scope (Device, Count, or Signal) + * @parent: parent component identification number + * @id: component identification number + */ +struct counter_component { + __u8 type; + __u8 scope; + __u8 parent; + __u8 id; +}; + +/* Event type definitions */ +#define COUNTER_EVENT_OVERFLOW 0 +#define COUNTER_EVENT_UNDERFLOW 1 +#define COUNTER_EVENT_OVERFLOW_UNDERFLOW 2 +#define COUNTER_EVENT_THRESHOLD 3 +#define COUNTER_EVENT_INDEX 4 + +/** + * struct counter_watch - Counter component watch configuration + * @component: component to watch when event triggers + * @event: event that triggers + * @channel: event channel + */ +struct counter_watch { + struct counter_component component; + __u8 event; + __u8 channel; +}; + +/* ioctl commands */ +#define COUNTER_CLEAR_WATCHES_IOCTL _IO(0x3E, 0x00) +#define COUNTER_ADD_WATCH_IOCTL _IOW(0x3E, 0x01, struct counter_watch) +#define COUNTER_LOAD_WATCHES_IOCTL _IO(0x3E, 0x02) + +/** + * struct counter_event - Counter event data + * @watch: component watch configuration + * @timestamp: best estimate of time of event occurrence, in nanoseconds + * @value: component value + */ +struct counter_event { + struct counter_watch watch; + __aligned_u64 timestamp; + __aligned_u64 value; +}; + +/* Count direction values */ +#define COUNTER_COUNT_DIRECTION_FORWARD 0 +#define COUNTER_COUNT_DIRECTION_BACKWARD 1 + +/* Count mode values */ +#define COUNTER_COUNT_MODE_NORMAL 0 +#define COUNTER_COUNT_MODE_RANGE_LIMIT 1 +#define COUNTER_COUNT_MODE_NON_RECYCLE 2 +#define COUNTER_COUNT_MODE_MODULO_N 3 + +/* Count function values */ +#define COUNTER_FUNCTION_INCREASE 0 +#define COUNTER_FUNCTION_DECREASE 1 +#define COUNTER_FUNCTION_PULSE_DIRECTION 2 +#define COUNTER_FUNCTION_QUADRATURE_X1_A 3 +#define COUNTER_FUNCTION_QUADRATURE_X1_B 4 +#define COUNTER_FUNCTION_QUADRATURE_X2_A 5 +#define COUNTER_FUNCTION_QUADRATURE_X2_B 6 +#define COUNTER_FUNCTION_QUADRATURE_X4 7 + +/* Signal values */ +#define COUNTER_SIGNAL_LEVEL_LOW 0 +#define COUNTER_SIGNAL_LEVEL_HIGH 1 + +/* Action mode values */ +#define COUNTER_SYNAPSE_ACTION_NONE 0 +#define COUNTER_SYNAPSE_ACTION_RISING_EDGE 1 +#define COUNTER_SYNAPSE_ACTION_FALLING_EDGE 2 +#define COUNTER_SYNAPSE_ACTION_BOTH_EDGES 3 + +#endif /* _UAPI_COUNTER_H_ */ -- 2.29.2
