diff options
author | Stephen Rothwell <sfr@canb.auug.org.au> | 2015-11-23 15:13:06 +1100 |
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committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2015-11-23 15:13:06 +1100 |
commit | 4c76a7ec9159ef8e56926454ce0dc8492ba735b0 (patch) | |
tree | 8daad3eb95d029fa2c6d5c681abf4ea375e63bcd | |
parent | d2c9dee1a8aa101e905108b58c8ff32a2fee07fd (diff) | |
parent | 5ccbdf2b710802e4673bd42e79c7029612256cd9 (diff) |
Merge branch 'akpm/master'
-rw-r--r-- | Documentation/ABI/testing/configfs-iio | 21 | ||||
-rw-r--r-- | Documentation/iio/iio_configfs.txt | 93 | ||||
-rw-r--r-- | drivers/iio/Kconfig | 16 | ||||
-rw-r--r-- | drivers/iio/Makefile | 2 | ||||
-rw-r--r-- | drivers/iio/industrialio-configfs.c | 50 | ||||
-rw-r--r-- | drivers/iio/industrialio-sw-trigger.c | 181 | ||||
-rw-r--r-- | drivers/iio/trigger/Kconfig | 10 | ||||
-rw-r--r-- | drivers/iio/trigger/Makefile | 2 | ||||
-rw-r--r-- | drivers/iio/trigger/iio-trig-hrtimer.c | 193 | ||||
-rw-r--r-- | include/linux/iio/sw_trigger.h | 71 |
10 files changed, 639 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/configfs-iio b/Documentation/ABI/testing/configfs-iio new file mode 100644 index 000000000000..2483756fccf5 --- /dev/null +++ b/Documentation/ABI/testing/configfs-iio @@ -0,0 +1,21 @@ +What: /config/iio +Date: October 2015 +KernelVersion: 4.4 +Contact: linux-iio@vger.kernel.org +Description: + This represents Industrial IO configuration entry point + directory. It contains sub-groups corresponding to IIO + objects. + +What: /config/iio/triggers +Date: October 2015 +KernelVersion: 4.4 +Description: + Industrial IO software triggers directory. + +What: /config/iio/triggers/hrtimers +Date: October 2015 +KernelVersion: 4.4 +Description: + High resolution timers directory. Creating a directory here + will result in creating a hrtimer trigger in the IIO subsystem. diff --git a/Documentation/iio/iio_configfs.txt b/Documentation/iio/iio_configfs.txt new file mode 100644 index 000000000000..f0add35cd52e --- /dev/null +++ b/Documentation/iio/iio_configfs.txt @@ -0,0 +1,93 @@ +Industrial IIO configfs support + +1. Overview + +Configfs is a filesystem-based manager of kernel objects. IIO uses some +objects that could be easily configured using configfs (e.g.: devices, +triggers). + +See Documentation/filesystems/configfs/configfs.txt for more information +about how configfs works. + +2. Usage + +In order to use configfs support in IIO we need to select it at compile +time via CONFIG_IIO_CONFIGFS config option. + +Then, mount the configfs filesystem (usually under /config directory): + +$ mkdir /config +$ mount -t configfs none /config + +At this point, all default IIO groups will be created and can be accessed +under /config/iio. Next chapters will describe available IIO configuration +objects. + +3. Software triggers + +One of the IIO default configfs groups is the "triggers" group. It is +automagically accessible when the configfs is mounted and can be found +under /config/iio/triggers. + +IIO software triggers implementation offers support for creating multiple +trigger types. A new trigger type is usually implemented as a separate +kernel module following the interface in include/linux/iio/sw_trigger.h: + +/* + * drivers/iio/trigger/iio-trig-sample.c + * sample kernel module implementing a new trigger type + */ +#include <linux/iio/sw_trigger.h> + + +static struct iio_sw_trigger *iio_trig_sample_probe(const char *name) +{ + /* + * This allocates and registers an IIO trigger plus other + * trigger type specific initialization. + */ +} + +static int iio_trig_hrtimer_remove(struct iio_sw_trigger *swt) +{ + /* + * This undoes the actions in iio_trig_sample_probe + */ +} + +static const struct iio_sw_trigger_ops iio_trig_sample_ops = { + .probe = iio_trig_sample_probe, + .remove = iio_trig_sample_remove, +}; + +static struct iio_sw_trigger_type iio_trig_sample = { + .name = "trig-sample", + .owner = THIS_MODULE, + .ops = &iio_trig_sample_ops, +}; + +module_iio_sw_trigger_driver(iio_trig_sample); + +Each trigger type has its own directory under /config/iio/triggers. Loading +iio-trig-sample module will create 'trig-sample' trigger type directory +/config/iio/triggers/trig-sample. + +We support the following interrupt sources (trigger types): + * hrtimer, uses high resolution timers as interrupt source + +3.1 Hrtimer triggers creation and destruction + +Loading iio-trig-hrtimer module will register hrtimer trigger types allowing +users to create hrtimer triggers under /config/iio/triggers/hrtimer. + +e.g: + +$ mkdir /config/triggers/hrtimer/instance1 +$ rmdir /config/triggers/hrtimer/instance1 + +Each trigger can have one or more attributes specific to the trigger type. + +3.2 "hrtimer" trigger types attributes + +"hrtimer" trigger type doesn't have any configurable attribute from /config dir. +It does introduce the sampling_frequency attribute to trigger directory. diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig index 66792e707d74..5dfb4f1c348c 100644 --- a/drivers/iio/Kconfig +++ b/drivers/iio/Kconfig @@ -22,6 +22,14 @@ if IIO_BUFFER source "drivers/iio/buffer/Kconfig" endif # IIO_BUFFER +config IIO_CONFIGFS + tristate "Enable IIO configuration via configfs" + select CONFIGFS_FS + help + This allows configuring various IIO bits through configfs + (e.g. software triggers). For more info see + Documentation/iio/iio_configfs.txt. + config IIO_TRIGGER bool "Enable triggered sampling support" help @@ -38,6 +46,14 @@ config IIO_CONSUMERS_PER_TRIGGER This value controls the maximum number of consumers that a given trigger may handle. Default is 2. +config IIO_SW_TRIGGER + tristate "Enable software triggers support" + select IIO_CONFIGFS + help + Provides IIO core support for software triggers. A software + trigger can be created via configfs or directly by a driver + using the API provided. + config IIO_TRIGGERED_EVENT tristate select IIO_TRIGGER diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile index aeca7269fe44..dc73c1f1583f 100644 --- a/drivers/iio/Makefile +++ b/drivers/iio/Makefile @@ -7,6 +7,8 @@ industrialio-y := industrialio-core.o industrialio-event.o inkern.o industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o +obj-$(CONFIG_IIO_CONFIGFS) += industrialio-configfs.o +obj-$(CONFIG_IIO_SW_TRIGGER) += industrialio-sw-trigger.o obj-$(CONFIG_IIO_TRIGGERED_EVENT) += industrialio-triggered-event.o obj-y += accel/ diff --git a/drivers/iio/industrialio-configfs.c b/drivers/iio/industrialio-configfs.c new file mode 100644 index 000000000000..83563dd7fcf4 --- /dev/null +++ b/drivers/iio/industrialio-configfs.c @@ -0,0 +1,50 @@ +/* + * Industrial I/O configfs bits + * + * Copyright (c) 2015 Intel Corporation + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/configfs.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kmod.h> +#include <linux/slab.h> + +#include <linux/iio/iio.h> + +static struct config_item_type iio_root_group_type = { + .ct_owner = THIS_MODULE, +}; + +struct configfs_subsystem iio_configfs_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "iio", + .ci_type = &iio_root_group_type, + }, + }, + .su_mutex = __MUTEX_INITIALIZER(iio_configfs_subsys.su_mutex), +}; +EXPORT_SYMBOL(iio_configfs_subsys); + +static int __init iio_configfs_init(void) +{ + config_group_init(&iio_configfs_subsys.su_group); + + return configfs_register_subsystem(&iio_configfs_subsys); +} +module_init(iio_configfs_init); + +static void __exit iio_configfs_exit(void) +{ + configfs_unregister_subsystem(&iio_configfs_subsys); +} +module_exit(iio_configfs_exit); + +MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>"); +MODULE_DESCRIPTION("Industrial I/O configfs support"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/iio/industrialio-sw-trigger.c b/drivers/iio/industrialio-sw-trigger.c new file mode 100644 index 000000000000..22262f68db6e --- /dev/null +++ b/drivers/iio/industrialio-sw-trigger.c @@ -0,0 +1,181 @@ +/* + * The Industrial I/O core, software trigger functions + * + * Copyright (c) 2015 Intel Corporation + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kmod.h> +#include <linux/list.h> +#include <linux/slab.h> + +#include <linux/iio/sw_trigger.h> +#include <linux/configfs.h> + +static struct config_group *iio_triggers_group; +static struct config_item_type iio_trigger_type_group_type; + +static struct config_item_type iio_triggers_group_type = { + .ct_owner = THIS_MODULE, +}; + +static LIST_HEAD(iio_trigger_types_list); +static DEFINE_MUTEX(iio_trigger_types_lock); + +static +struct iio_sw_trigger_type *__iio_find_sw_trigger_type(const char *name, + unsigned len) +{ + struct iio_sw_trigger_type *t = NULL, *iter; + + list_for_each_entry(iter, &iio_trigger_types_list, list) + if (!strcmp(iter->name, name)) { + t = iter; + break; + } + + return t; +} + +int iio_register_sw_trigger_type(struct iio_sw_trigger_type *t) +{ + struct iio_sw_trigger_type *iter; + int ret = 0; + + mutex_lock(&iio_trigger_types_lock); + iter = __iio_find_sw_trigger_type(t->name, strlen(t->name)); + if (iter) + ret = -EBUSY; + else + list_add_tail(&t->list, &iio_trigger_types_list); + mutex_unlock(&iio_trigger_types_lock); + + if (ret) + return ret; + + t->group = configfs_register_default_group(iio_triggers_group, t->name, + &iio_trigger_type_group_type); + if (IS_ERR(t->group)) + ret = PTR_ERR(t->group); + + return ret; +} +EXPORT_SYMBOL(iio_register_sw_trigger_type); + +void iio_unregister_sw_trigger_type(struct iio_sw_trigger_type *t) +{ + struct iio_sw_trigger_type *iter; + + mutex_lock(&iio_trigger_types_lock); + iter = __iio_find_sw_trigger_type(t->name, strlen(t->name)); + if (iter) + list_del(&t->list); + mutex_unlock(&iio_trigger_types_lock); + + configfs_unregister_default_group(t->group); +} +EXPORT_SYMBOL(iio_unregister_sw_trigger_type); + +static +struct iio_sw_trigger_type *iio_get_sw_trigger_type(const char *name) +{ + struct iio_sw_trigger_type *t; + + mutex_lock(&iio_trigger_types_lock); + t = __iio_find_sw_trigger_type(name, strlen(name)); + if (t && !try_module_get(t->owner)) + t = NULL; + mutex_unlock(&iio_trigger_types_lock); + + return t; +} + +struct iio_sw_trigger *iio_sw_trigger_create(const char *type, const char *name) +{ + struct iio_sw_trigger *t; + struct iio_sw_trigger_type *tt; + + tt = iio_get_sw_trigger_type(type); + if (!tt) { + pr_err("Invalid trigger type: %s\n", type); + return ERR_PTR(-EINVAL); + } + t = tt->ops->probe(name); + if (IS_ERR(t)) + goto out_module_put; + + t->trigger_type = tt; + + return t; +out_module_put: + module_put(tt->owner); + return t; +} +EXPORT_SYMBOL(iio_sw_trigger_create); + +void iio_sw_trigger_destroy(struct iio_sw_trigger *t) +{ + struct iio_sw_trigger_type *tt = t->trigger_type; + + tt->ops->remove(t); + module_put(tt->owner); +} +EXPORT_SYMBOL(iio_sw_trigger_destroy); + +static struct config_group *trigger_make_group(struct config_group *group, + const char *name) +{ + struct iio_sw_trigger *t; + + t = iio_sw_trigger_create(group->cg_item.ci_name, name); + if (IS_ERR(t)) + return ERR_CAST(t); + + config_item_set_name(&t->group.cg_item, "%s", name); + + return &t->group; +} + +static void trigger_drop_group(struct config_group *group, + struct config_item *item) +{ + struct iio_sw_trigger *t = to_iio_sw_trigger(item); + + iio_sw_trigger_destroy(t); + config_item_put(item); +} + +static struct configfs_group_operations trigger_ops = { + .make_group = &trigger_make_group, + .drop_item = &trigger_drop_group, +}; + +static struct config_item_type iio_trigger_type_group_type = { + .ct_group_ops = &trigger_ops, + .ct_owner = THIS_MODULE, +}; + +static int __init iio_sw_trigger_init(void) +{ + iio_triggers_group = + configfs_register_default_group(&iio_configfs_subsys.su_group, + "triggers", + &iio_triggers_group_type); + return PTR_ERR_OR_ZERO(iio_triggers_group); +} +module_init(iio_sw_trigger_init); + +static void __exit iio_sw_trigger_exit(void) +{ + configfs_unregister_default_group(iio_triggers_group); +} +module_exit(iio_sw_trigger_exit); + +MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>"); +MODULE_DESCRIPTION("Industrial I/O software triggers support"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/iio/trigger/Kconfig b/drivers/iio/trigger/Kconfig index 79996123a71b..519e6772f6f5 100644 --- a/drivers/iio/trigger/Kconfig +++ b/drivers/iio/trigger/Kconfig @@ -5,6 +5,16 @@ menu "Triggers - standalone" +config IIO_HRTIMER_TRIGGER + tristate "High resolution timer trigger" + depends on IIO_SW_TRIGGER + help + Provides a frequency based IIO trigger using high resolution + timers as interrupt source. + + To compile this driver as a module, choose M here: the + module will be called iio-trig-hrtimer. + config IIO_INTERRUPT_TRIGGER tristate "Generic interrupt trigger" help diff --git a/drivers/iio/trigger/Makefile b/drivers/iio/trigger/Makefile index 0694daecaf22..fe06eb564367 100644 --- a/drivers/iio/trigger/Makefile +++ b/drivers/iio/trigger/Makefile @@ -3,5 +3,7 @@ # # When adding new entries keep the list in alphabetical order + +obj-$(CONFIG_IIO_HRTIMER_TRIGGER) += iio-trig-hrtimer.o obj-$(CONFIG_IIO_INTERRUPT_TRIGGER) += iio-trig-interrupt.o obj-$(CONFIG_IIO_SYSFS_TRIGGER) += iio-trig-sysfs.o diff --git a/drivers/iio/trigger/iio-trig-hrtimer.c b/drivers/iio/trigger/iio-trig-hrtimer.c new file mode 100644 index 000000000000..5e6d451febeb --- /dev/null +++ b/drivers/iio/trigger/iio-trig-hrtimer.c @@ -0,0 +1,193 @@ +/** + * The industrial I/O periodic hrtimer trigger driver + * + * Copyright (C) Intuitive Aerial AB + * Written by Marten Svanfeldt, marten@intuitiveaerial.com + * Copyright (C) 2012, Analog Device Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * Copyright (C) 2015, Intel Corporation + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + */ +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/hrtimer.h> + +#include <linux/iio/iio.h> +#include <linux/iio/trigger.h> +#include <linux/iio/sw_trigger.h> + +/* default sampling frequency - 100Hz */ +#define HRTIMER_DEFAULT_SAMPLING_FREQUENCY 100 + +struct iio_hrtimer_info { + struct iio_sw_trigger swt; + struct hrtimer timer; + unsigned long sampling_frequency; + ktime_t period; +}; + +static struct config_item_type iio_hrtimer_type = { + .ct_owner = THIS_MODULE, +}; + +static +ssize_t iio_hrtimer_show_sampling_frequency(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_trigger *trig = to_iio_trigger(dev); + struct iio_hrtimer_info *info = iio_trigger_get_drvdata(trig); + + return snprintf(buf, PAGE_SIZE, "%lu\n", info->sampling_frequency); +} + +static +ssize_t iio_hrtimer_store_sampling_frequency(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_trigger *trig = to_iio_trigger(dev); + struct iio_hrtimer_info *info = iio_trigger_get_drvdata(trig); + unsigned long val; + int ret; + + ret = kstrtoul(buf, 10, &val); + if (ret) + return ret; + + if (!val || val > NSEC_PER_SEC) + return -EINVAL; + + info->sampling_frequency = val; + info->period = ktime_set(0, NSEC_PER_SEC / val); + + return len; +} + +static DEVICE_ATTR(sampling_frequency, S_IRUGO | S_IWUSR, + iio_hrtimer_show_sampling_frequency, + iio_hrtimer_store_sampling_frequency); + +static struct attribute *iio_hrtimer_attrs[] = { + &dev_attr_sampling_frequency.attr, + NULL +}; + +static const struct attribute_group iio_hrtimer_attr_group = { + .attrs = iio_hrtimer_attrs, +}; + +static const struct attribute_group *iio_hrtimer_attr_groups[] = { + &iio_hrtimer_attr_group, + NULL +}; + +static enum hrtimer_restart iio_hrtimer_trig_handler(struct hrtimer *timer) +{ + struct iio_hrtimer_info *info; + + info = container_of(timer, struct iio_hrtimer_info, timer); + + hrtimer_forward_now(timer, info->period); + iio_trigger_poll(info->swt.trigger); + + return HRTIMER_RESTART; +} + +static int iio_trig_hrtimer_set_state(struct iio_trigger *trig, bool state) +{ + struct iio_hrtimer_info *trig_info; + + trig_info = iio_trigger_get_drvdata(trig); + + if (state) + hrtimer_start(&trig_info->timer, trig_info->period, + HRTIMER_MODE_REL); + else + hrtimer_cancel(&trig_info->timer); + + return 0; +} + +static const struct iio_trigger_ops iio_hrtimer_trigger_ops = { + .owner = THIS_MODULE, + .set_trigger_state = iio_trig_hrtimer_set_state, +}; + +static struct iio_sw_trigger *iio_trig_hrtimer_probe(const char *name) +{ + struct iio_hrtimer_info *trig_info; + int ret; + + trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL); + if (!trig_info) + return ERR_PTR(-ENOMEM); + + trig_info->swt.trigger = iio_trigger_alloc("%s", name); + if (!trig_info->swt.trigger) { + ret = -ENOMEM; + goto err_free_trig_info; + } + + iio_trigger_set_drvdata(trig_info->swt.trigger, trig_info); + trig_info->swt.trigger->ops = &iio_hrtimer_trigger_ops; + trig_info->swt.trigger->dev.groups = iio_hrtimer_attr_groups; + + hrtimer_init(&trig_info->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + trig_info->timer.function = iio_hrtimer_trig_handler; + + trig_info->sampling_frequency = HRTIMER_DEFAULT_SAMPLING_FREQUENCY; + trig_info->period = ktime_set(0, NSEC_PER_SEC / + trig_info->sampling_frequency); + + ret = iio_trigger_register(trig_info->swt.trigger); + if (ret) + goto err_free_trigger; + + iio_swt_group_init_type_name(&trig_info->swt, name, &iio_hrtimer_type); + return &trig_info->swt; +err_free_trigger: + iio_trigger_free(trig_info->swt.trigger); +err_free_trig_info: + kfree(trig_info); + + return ERR_PTR(ret); +} + +static int iio_trig_hrtimer_remove(struct iio_sw_trigger *swt) +{ + struct iio_hrtimer_info *trig_info; + + trig_info = iio_trigger_get_drvdata(swt->trigger); + + iio_trigger_unregister(swt->trigger); + + /* cancel the timer after unreg to make sure no one rearms it */ + hrtimer_cancel(&trig_info->timer); + iio_trigger_free(swt->trigger); + kfree(trig_info); + + return 0; +} + +static const struct iio_sw_trigger_ops iio_trig_hrtimer_ops = { + .probe = iio_trig_hrtimer_probe, + .remove = iio_trig_hrtimer_remove, +}; + +static struct iio_sw_trigger_type iio_trig_hrtimer = { + .name = "hrtimer", + .owner = THIS_MODULE, + .ops = &iio_trig_hrtimer_ops, +}; + +module_iio_sw_trigger_driver(iio_trig_hrtimer); + +MODULE_AUTHOR("Marten Svanfeldt <marten@intuitiveaerial.com>"); +MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>"); +MODULE_DESCRIPTION("Periodic hrtimer trigger for the IIO subsystem"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/iio/sw_trigger.h b/include/linux/iio/sw_trigger.h new file mode 100644 index 000000000000..c2f33b2b35a5 --- /dev/null +++ b/include/linux/iio/sw_trigger.h @@ -0,0 +1,71 @@ +/* + * Industrial I/O software trigger interface + * + * Copyright (c) 2015 Intel Corporation + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#ifndef __IIO_SW_TRIGGER +#define __IIO_SW_TRIGGER + +#include <linux/module.h> +#include <linux/device.h> +#include <linux/iio/iio.h> +#include <linux/configfs.h> + +#define module_iio_sw_trigger_driver(__iio_sw_trigger_type) \ + module_driver(__iio_sw_trigger_type, iio_register_sw_trigger_type, \ + iio_unregister_sw_trigger_type) + +extern struct configfs_subsystem iio_configfs_subsys; +struct iio_sw_trigger_ops; + +struct iio_sw_trigger_type { + const char *name; + struct module *owner; + const struct iio_sw_trigger_ops *ops; + struct list_head list; + struct config_group *group; +}; + +struct iio_sw_trigger { + struct iio_trigger *trigger; + struct iio_sw_trigger_type *trigger_type; + struct config_group group; +}; + +struct iio_sw_trigger_ops { + struct iio_sw_trigger* (*probe)(const char *); + int (*remove)(struct iio_sw_trigger *); +}; + +static inline +struct iio_sw_trigger *to_iio_sw_trigger(struct config_item *item) +{ + return container_of(to_config_group(item), struct iio_sw_trigger, + group); +} + +int iio_register_sw_trigger_type(struct iio_sw_trigger_type *tt); +void iio_unregister_sw_trigger_type(struct iio_sw_trigger_type *tt); + +struct iio_sw_trigger *iio_sw_trigger_create(const char *, const char *); +void iio_sw_trigger_destroy(struct iio_sw_trigger *); + +int iio_sw_trigger_type_configfs_register(struct iio_sw_trigger_type *tt); +void iio_sw_trigger_type_configfs_unregister(struct iio_sw_trigger_type *tt); + +static inline +void iio_swt_group_init_type_name(struct iio_sw_trigger *t, + const char *name, + struct config_item_type *type) +{ +#ifdef CONFIG_CONFIGFS_FS + config_group_init_type_name(&t->group, name, type); +#endif +} + +#endif /* __IIO_SW_TRIGGER */ |