This creates an IIO configfs subsystem named "iio", which has one default
group named "triggers". This allows us to easily create/destroy software
triggers. One must create a driver which implements iio_configfs_trigger.h
interface and then add its trigger type to IIO configfs core.
See Documentation/iio/iio_configfs.txt for more details on how configfs
support for IIO works.
Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
---
drivers/iio/Kconfig | 8 +
drivers/iio/Makefile | 1 +
drivers/iio/industrialio-configfs.c | 297 +++++++++++++++++++++++++++++++
include/linux/iio/iio_configfs_trigger.h | 48 +++++
4 files changed, 354 insertions(+)
create mode 100644 drivers/iio/industrialio-configfs.c
create mode 100644 include/linux/iio/iio_configfs_trigger.h
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 4132935..39f1b69 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -18,6 +18,14 @@ config IIO_BUFFER
Provide core support for various buffer based data
acquisition methods.
+config IIO_CONFIGFS
+ tristate "Enable IIO configuration via configfs"
+ select CONFIGFS_FS
+ help
+ This allows configuring various IIO bits through configfs
+ (e.g software trigger creation / destruction). For more info
+ see Documentation/iio/iio_configfs.txt.
+
if IIO_BUFFER
config IIO_BUFFER_CB
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 698afc2..90cc407 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -5,6 +5,7 @@
obj-$(CONFIG_IIO) += industrialio.o
industrialio-y := industrialio-core.o industrialio-event.o inkern.o
industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o
+industrialio-$(CONFIG_IIO_CONFIGFS) += industrialio-configfs.o
industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
industrialio-$(CONFIG_IIO_BUFFER_CB) += buffer_cb.o
diff --git a/drivers/iio/industrialio-configfs.c b/drivers/iio/industrialio-configfs.c
new file mode 100644
index 0000000..4d2133a
--- /dev/null
+++ b/drivers/iio/industrialio-configfs.c
@@ -0,0 +1,297 @@
+/*
+ * 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/slab.h>
+
+#include <linux/iio/iio_configfs_trigger.h>
+
+static const char *trigger_types[] =
+{
+ "none",
+};
+
+struct iio_configfs_ops iio_none_ops = {
+ .get_freq = iio_none_get_freq,
+ .set_freq = iio_none_set_freq,
+ .probe = iio_none_probe,
+ .remove = iio_none_remove,
+};
+
+struct iio_trigger_item {
+ struct config_item item;
+ struct iio_configfs_trigger_info *trigger_info;
+};
+
+static
+inline struct iio_trigger_item *to_iio_trigger_item(struct config_item *item)
+{
+ if (!item)
+ return NULL;
+ return container_of(item, struct iio_trigger_item, item);
+}
+
+static unsigned int iio_trigger_get_type(const char *type_str)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(trigger_types); i++) {
+ if (!strncmp(trigger_types[i], type_str,
+ strlen(trigger_types[i])))
+ return i;
+ }
+ return -EINVAL;
+}
+
+static
+void iio_trigger_set_configfs_ops(struct iio_configfs_trigger_info *trig_info,
+ unsigned int type)
+{
+ switch (type) {
+ case IIO_TRIGGER_TYPE_NONE:
+ trig_info->configfs_ops = &iio_none_ops;
+ break;
+ default:
+ pr_err("Setting configfs ops failed! Unknown type %d\n", type);
+ break;
+ }
+}
+
+CONFIGFS_ATTR_STRUCT(iio_trigger_item);
+
+#define IIO_TRIGGER_ITEM_ATTR(_name, _mode, _show, _store) \
+struct iio_trigger_item_attribute iio_trigger_item_attr_##_name = \
+ __CONFIGFS_ATTR(_name, _mode, _show, _store)
+
+static ssize_t iio_trigger_item_type_read(struct iio_trigger_item *item,
+ char *page)
+{
+ return sprintf(page, "%s\n", trigger_types[item->trigger_info->type]);
+}
+
+static ssize_t iio_trigger_item_type_write(struct iio_trigger_item *item,
+ const char *page, size_t count)
+{
+ int type;
+
+ if (item->trigger_info->active)
+ return -EBUSY;
+
+ type = iio_trigger_get_type(page);
+ if (type < 0)
+ return -EINVAL;
+
+ item->trigger_info->type = type;
+
+ iio_trigger_set_configfs_ops(item->trigger_info, type);
+
+ return count;
+}
+
+static ssize_t iio_trigger_item_activate_read(struct iio_trigger_item *item,
+ char *page)
+{
+ return sprintf(page, "%d\n", item->trigger_info->active);
+}
+
+static ssize_t iio_trigger_item_activate_write(struct iio_trigger_item *item,
+ const char *page, size_t count)
+{
+ bool requested_action;
+ int ret;
+
+ ret = strtobool(page, &requested_action);
+ if (ret < 0)
+ return ret;
+
+ if (requested_action == item->trigger_info->active)
+ return -EINVAL;
+
+ if (requested_action)
+ item->trigger_info->configfs_ops->probe(item->trigger_info);
+ else
+ item->trigger_info->configfs_ops->remove(item->trigger_info);
+
+ item->trigger_info->active = requested_action;
+
+ return count;
+}
+
+static
+ssize_t iio_trigger_item_get_sampling_freq(struct iio_trigger_item *item,
+ char *page)
+{
+ int ret;
+
+ if (!item->trigger_info->active)
+ return -ENODEV;
+
+ ret = item->trigger_info->configfs_ops->get_freq(item->trigger_info);
+ if (ret < 0)
+ return ret;
+ return sprintf(page, "%d\n", ret);
+}
+
+static
+ssize_t iio_trigger_item_set_sampling_freq(struct iio_trigger_item *item,
+ const char *page,
+ size_t count)
+{
+ int ret;
+ unsigned long freq;
+
+ if (!item->trigger_info->active)
+ return -ENODEV;
+
+ ret = kstrtoul(page, 10, &freq);
+ if (ret < 0)
+ return 0;
+
+ ret = item->trigger_info->configfs_ops->set_freq(item->trigger_info,
+ freq);
+ if (ret < 0)
+ return ret;
+
+ return count;
+}
+
+IIO_TRIGGER_ITEM_ATTR(type, S_IRUGO | S_IWUSR,
+ iio_trigger_item_type_read,
+ iio_trigger_item_type_write);
+
+IIO_TRIGGER_ITEM_ATTR(activate, S_IRUGO | S_IWUSR,
+ iio_trigger_item_activate_read,
+ iio_trigger_item_activate_write);
+
+IIO_TRIGGER_ITEM_ATTR(sampling_frequency, S_IRUGO | S_IWUSR,
+ iio_trigger_item_get_sampling_freq,
+ iio_trigger_item_set_sampling_freq);
+
+static struct configfs_attribute *iio_trigger_item_attrs[] = {
+ &iio_trigger_item_attr_type.attr,
+ &iio_trigger_item_attr_sampling_frequency.attr,
+ &iio_trigger_item_attr_activate.attr,
+ NULL
+};
+
+CONFIGFS_ATTR_OPS(iio_trigger_item);
+
+static struct configfs_item_operations iio_trigger_item_ops = {
+ .show_attribute = iio_trigger_item_attr_show,
+ .store_attribute = iio_trigger_item_attr_store,
+};
+
+static struct config_item_type iio_triggers_item_type;
+
+static struct config_item *iio_triggers_make_item(struct config_group *group,
+ const char *name)
+{
+ struct iio_trigger_item *trigger_item;
+ struct iio_configfs_trigger_info *trigger_info;
+
+ trigger_item = kzalloc(sizeof(*trigger_item), GFP_KERNEL);
+ if (!trigger_item)
+ return ERR_PTR(-ENOMEM);
+ trigger_info = kzalloc(sizeof(*trigger_info), GFP_KERNEL);
+ if (!trigger_info)
+ goto out_free_trigger_item;
+
+ trigger_info->name = kstrdup(name, GFP_KERNEL);
+ if (!trigger_info->name)
+ goto out_free_trigger_info;
+
+ trigger_info->type = IIO_TRIGGER_TYPE_NONE;
+ trigger_info->configfs_ops = &iio_none_ops;
+
+ trigger_item->trigger_info = trigger_info;
+ config_item_init_type_name(&trigger_item->item, name,
+ &iio_triggers_item_type);
+
+ return &trigger_item->item;
+out_free_trigger_info:
+ kfree(trigger_info);
+out_free_trigger_item:
+ kfree(trigger_item);
+ return ERR_PTR(-ENOMEM);
+}
+
+static void iio_triggers_drop_item(struct config_group *group,
+ struct config_item *item)
+{
+ struct iio_trigger_item *trigger_item;
+
+ trigger_item = container_of(item, struct iio_trigger_item, item);
+
+ kfree(trigger_item->trigger_info->name);
+ kfree(trigger_item->trigger_info);
+ kfree(trigger_item);
+}
+
+static struct configfs_group_operations iio_triggers_group_ops = {
+ .make_item = iio_triggers_make_item,
+ .drop_item = iio_triggers_drop_item,
+};
+
+static struct config_item_type iio_triggers_item_type = {
+ .ct_owner = THIS_MODULE,
+ .ct_item_ops = &iio_trigger_item_ops,
+ .ct_attrs = iio_trigger_item_attrs,
+};
+
+static struct config_item_type iio_triggers_root_type = {
+ .ct_owner = THIS_MODULE,
+ .ct_group_ops = &iio_triggers_group_ops,
+};
+
+static struct config_group iio_triggers_group = {
+ .cg_item = {
+ .ci_namebuf = "triggers",
+ .ci_type = &iio_triggers_root_type,
+ },
+};
+
+static struct config_group *iio_default_groups[] = {
+ &iio_triggers_group,
+ NULL
+};
+
+static struct config_item_type iio_root_group_type = {
+ .ct_owner = THIS_MODULE,
+};
+
+static struct configfs_subsystem iio_configfs_subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "iio",
+ .ci_type = &iio_root_group_type,
+ },
+ .default_groups = iio_default_groups,
+ },
+ .su_mutex = __MUTEX_INITIALIZER(iio_configfs_subsys.su_mutex),
+};
+
+static int __init iio_configfs_init(void)
+{
+ config_group_init(&iio_triggers_group);
+ 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@xxxxxxxxx>");
+MODULE_DESCRIPTION("Industrial I/O configfs support");
diff --git a/include/linux/iio/iio_configfs_trigger.h b/include/linux/iio/iio_configfs_trigger.h
new file mode 100644
index 0000000..e7b5777
--- /dev/null
+++ b/include/linux/iio/iio_configfs_trigger.h
@@ -0,0 +1,48 @@
+#ifndef __IIO_CONFIGFS_TRIGGER
+#define __IIO_CONFIGFS_TRIGGER
+
+#define IIO_TRIGGER_TYPE_NONE 0
+
+struct iio_configfs_trigger_info {
+ const char *name;
+ unsigned int type;
+ unsigned int active;
+ struct iio_trigger *trigger;
+ struct iio_configfs_ops *configfs_ops;
+};
+
+struct iio_configfs_ops {
+ int (*get_freq)(struct iio_configfs_trigger_info* );
+ int (*set_freq)(struct iio_configfs_trigger_info *, unsigned long);
+ int (*probe)(struct iio_configfs_trigger_info* );
+ int (*remove)(struct iio_configfs_trigger_info* );
+};
+
+static
+inline int iio_none_get_freq(struct iio_configfs_trigger_info *trigger_info)
+{
+ return 0;
+}
+
+static
+inline int iio_none_set_freq(struct iio_configfs_trigger_info *trigger_info,
+ unsigned long f)
+{
+ return 0;
+}
+
+static
+inline int iio_none_probe(struct iio_configfs_trigger_info *trigger_info)
+{
+ return 0;
+}
+
+static
+inline int iio_none_remove(struct iio_configfs_trigger_info *trigger_info)
+{
+ return 0;
+}
+
+extern struct iio_configfs_ops iio_hrtimer_ops;
+
+#endif /* __IIO_CONFIGFS_TRIGGER */
--
1.9.1
--
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