On 20/04/15 15:02, Daniel Baluta wrote:
> This creates an IIO configfs subystem named "iio", with a default "triggers"
> group.
>
> Triggers group is used for handling software triggers. To create a new
> software
> trigger one must create a directory inside the trigger directory.
>
> Software trigger name MUST follow the following convention:
> * <trigger-type>-<trigger-name>
> Where:
> * <trigger_type>, specifies the interrupt source (e.g: hrtimer)
> * <trigger-name>, specifies the IIO device trigger name
>
> Failing to follow this convention will result in an directory creation error.
>
> E.g, assuming that hrtimer trigger type is registered with IIO software
> trigger core:
>
> $ mkdir /config/iio/triggers/hrtimer-instance1
>
> Signed-off-by: Daniel Baluta <daniel.bal...@intel.com>
Looks good. Couple of little comments inline.
Jonathan
> ---
> drivers/iio/Kconfig | 8 +++
> drivers/iio/Makefile | 1 +
> drivers/iio/industrialio-configfs.c | 117
> ++++++++++++++++++++++++++++++++++++
> 3 files changed, 126 insertions(+)
> create mode 100644 drivers/iio/industrialio-configfs.c
>
> diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
> index de7f1d9..c310156 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 triggers). 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 df87975..31aead3 100644
> --- a/drivers/iio/Makefile
> +++ b/drivers/iio/Makefile
> @@ -10,6 +10,7 @@ industrialio-$(CONFIG_IIO_SW_TRIGGER) +=
> industrialio-sw-trigger.o
> industrialio-$(CONFIG_IIO_BUFFER_CB) += buffer_cb.o
>
> obj-$(CONFIG_IIO_TRIGGERED_BUFFER) += industrialio-triggered-buffer.o
> +obj-$(CONFIG_IIO_CONFIGFS) += industrialio-configfs.o
> obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
>
> obj-y += accel/
> diff --git a/drivers/iio/industrialio-configfs.c
> b/drivers/iio/industrialio-configfs.c
> new file mode 100644
> index 0000000..0361434
> --- /dev/null
> +++ b/drivers/iio/industrialio-configfs.c
> @@ -0,0 +1,117 @@
> +/*
> + * 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>
> +#include <linux/iio/sw_trigger.h>
> +
> +#define MAX_NAME_LEN 32
Strikes me as perhaps a little short given we want to allow 'almost' arbitary
names for the triggers.
> +
> +static struct config_group *trigger_make_group(struct config_group *group,
> + const char *name)
> +{
> + char *type_name;
> + char *trigger_name;
> + char buf[MAX_NAME_LEN];
> + struct iio_sw_trigger *t;
> +
> + snprintf(buf, MAX_NAME_LEN, "%s", name);
> +
> + /* group name should have the form <trigger-type>-<trigger-name> */
> + type_name = buf;
> + trigger_name = strchr(buf, '-');
> + if (!trigger_name) {
> + pr_err("Unable to locate '-' in %s. Use <type>-<name>.\n", buf);
> + return ERR_PTR(-EINVAL);
> + }
> +
> + /* replace - with \0, this nicely separates the two strings */
> + *trigger_name = '\0';
Dirty trick, but I like it.
> + trigger_name++;
> +
> + t = iio_sw_trigger_create(type_name, trigger_name);
> + if (IS_ERR(t))
> + return ERR_CAST(t);
> +
> + config_item_set_name(&t->group.cg_item, 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);
> +
> + if (t)
> + iio_sw_trigger_destroy(t);
> + config_item_put(item);
> +}
> +
> +static struct configfs_group_operations triggers_ops = {
> + .make_group = &trigger_make_group,
> + .drop_item = &trigger_drop_group,
> +};
> +
> +static struct config_item_type iio_triggers_group_type = {
> + .ct_group_ops = &triggers_ops,
> + .ct_owner = THIS_MODULE,
> +};
> +
> +static struct config_group iio_triggers_group = {
> + .cg_item = {
> + .ci_namebuf = "triggers",
> + .ci_type = &iio_triggers_group_type,
> + },
> +};
> +
> +static struct config_group *iio_root_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_root_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.bal...@intel.com>");
> +MODULE_DESCRIPTION("Industrial I/O configfs support");
> +MODULE_LICENSE("GPL v2");
>
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