diff options
author | Jonathan Cameron <jic23@kernel.org> | 2012-04-25 14:54:59 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-04-25 18:11:38 (GMT) |
commit | a980e046098b0a40eaff5e4e7fcde6cf035b7c06 (patch) | |
tree | 23375fc2bba39f088974cf621f7abf006d43d087 /drivers/iio/industrialio-trigger.c | |
parent | 06458e277eac2b8761b0a04d3c808d57be281a2e (diff) | |
download | linux-a980e046098b0a40eaff5e4e7fcde6cf035b7c06.tar.xz |
IIO: Move the core files to drivers/iio
Take the core support + the kfifo buffer implentation out of
staging. Whilst we are far from done in improving this subsystem
it is now at a stage where the userspae interfaces (provided by
the core) can be considered stable.
Drivers will follow over a longer time scale.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/iio/industrialio-trigger.c')
-rw-r--r-- | drivers/iio/industrialio-trigger.c | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c new file mode 100644 index 0000000..03fee2e --- /dev/null +++ b/drivers/iio/industrialio-trigger.c @@ -0,0 +1,509 @@ +/* The industrial I/O core, trigger handling functions + * + * Copyright (c) 2008 Jonathan Cameron + * + * 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/idr.h> +#include <linux/err.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/slab.h> + +#include <linux/iio/iio.h> +#include <linux/iio/trigger.h> +#include "iio_core.h" +#include "iio_core_trigger.h" +#include <linux/iio/trigger_consumer.h> + +/* RFC - Question of approach + * Make the common case (single sensor single trigger) + * simple by starting trigger capture from when first sensors + * is added. + * + * Complex simultaneous start requires use of 'hold' functionality + * of the trigger. (not implemented) + * + * Any other suggestions? + */ + +static DEFINE_IDA(iio_trigger_ida); + +/* Single list of all available triggers */ +static LIST_HEAD(iio_trigger_list); +static DEFINE_MUTEX(iio_trigger_list_lock); + +/** + * iio_trigger_read_name() - retrieve useful identifying name + **/ +static ssize_t iio_trigger_read_name(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_trigger *trig = dev_get_drvdata(dev); + return sprintf(buf, "%s\n", trig->name); +} + +static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL); + +/** + * iio_trigger_register_sysfs() - create a device for this trigger + * @trig_info: the trigger + * + * Also adds any control attribute registered by the trigger driver + **/ +static int iio_trigger_register_sysfs(struct iio_trigger *trig_info) +{ + return sysfs_add_file_to_group(&trig_info->dev.kobj, + &dev_attr_name.attr, + NULL); +} + +static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info) +{ + sysfs_remove_file_from_group(&trig_info->dev.kobj, + &dev_attr_name.attr, + NULL); +} + +int iio_trigger_register(struct iio_trigger *trig_info) +{ + int ret; + + trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL); + if (trig_info->id < 0) { + ret = trig_info->id; + goto error_ret; + } + /* Set the name used for the sysfs directory etc */ + dev_set_name(&trig_info->dev, "trigger%ld", + (unsigned long) trig_info->id); + + ret = device_add(&trig_info->dev); + if (ret) + goto error_unregister_id; + + ret = iio_trigger_register_sysfs(trig_info); + if (ret) + goto error_device_del; + + /* Add to list of available triggers held by the IIO core */ + mutex_lock(&iio_trigger_list_lock); + list_add_tail(&trig_info->list, &iio_trigger_list); + mutex_unlock(&iio_trigger_list_lock); + + return 0; + +error_device_del: + device_del(&trig_info->dev); +error_unregister_id: + ida_simple_remove(&iio_trigger_ida, trig_info->id); +error_ret: + return ret; +} +EXPORT_SYMBOL(iio_trigger_register); + +void iio_trigger_unregister(struct iio_trigger *trig_info) +{ + mutex_lock(&iio_trigger_list_lock); + list_del(&trig_info->list); + mutex_unlock(&iio_trigger_list_lock); + + iio_trigger_unregister_sysfs(trig_info); + ida_simple_remove(&iio_trigger_ida, trig_info->id); + /* Possible issue in here */ + device_unregister(&trig_info->dev); +} +EXPORT_SYMBOL(iio_trigger_unregister); + +static struct iio_trigger *iio_trigger_find_by_name(const char *name, + size_t len) +{ + struct iio_trigger *trig = NULL, *iter; + + mutex_lock(&iio_trigger_list_lock); + list_for_each_entry(iter, &iio_trigger_list, list) + if (sysfs_streq(iter->name, name)) { + trig = iter; + break; + } + mutex_unlock(&iio_trigger_list_lock); + + return trig; +} + +void iio_trigger_poll(struct iio_trigger *trig, s64 time) +{ + int i; + if (!trig->use_count) + for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) + if (trig->subirqs[i].enabled) { + trig->use_count++; + generic_handle_irq(trig->subirq_base + i); + } +} +EXPORT_SYMBOL(iio_trigger_poll); + +irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private) +{ + iio_trigger_poll(private, iio_get_time_ns()); + return IRQ_HANDLED; +} +EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll); + +void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time) +{ + int i; + if (!trig->use_count) + for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) + if (trig->subirqs[i].enabled) { + trig->use_count++; + handle_nested_irq(trig->subirq_base + i); + } +} +EXPORT_SYMBOL(iio_trigger_poll_chained); + +void iio_trigger_notify_done(struct iio_trigger *trig) +{ + trig->use_count--; + if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable) + if (trig->ops->try_reenable(trig)) + /* Missed and interrupt so launch new poll now */ + iio_trigger_poll(trig, 0); +} +EXPORT_SYMBOL(iio_trigger_notify_done); + +/* Trigger Consumer related functions */ +static int iio_trigger_get_irq(struct iio_trigger *trig) +{ + int ret; + mutex_lock(&trig->pool_lock); + ret = bitmap_find_free_region(trig->pool, + CONFIG_IIO_CONSUMERS_PER_TRIGGER, + ilog2(1)); + mutex_unlock(&trig->pool_lock); + if (ret >= 0) + ret += trig->subirq_base; + + return ret; +} + +static void iio_trigger_put_irq(struct iio_trigger *trig, int irq) +{ + mutex_lock(&trig->pool_lock); + clear_bit(irq - trig->subirq_base, trig->pool); + mutex_unlock(&trig->pool_lock); +} + +/* Complexity in here. With certain triggers (datardy) an acknowledgement + * may be needed if the pollfuncs do not include the data read for the + * triggering device. + * This is not currently handled. Alternative of not enabling trigger unless + * the relevant function is in there may be the best option. + */ +/* Worth protecting against double additions?*/ +static int iio_trigger_attach_poll_func(struct iio_trigger *trig, + struct iio_poll_func *pf) +{ + int ret = 0; + bool notinuse + = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER); + + /* Prevent the module being removed whilst attached to a trigger */ + __module_get(pf->indio_dev->info->driver_module); + pf->irq = iio_trigger_get_irq(trig); + ret = request_threaded_irq(pf->irq, pf->h, pf->thread, + pf->type, pf->name, + pf); + if (ret < 0) { + module_put(pf->indio_dev->info->driver_module); + return ret; + } + + if (trig->ops && trig->ops->set_trigger_state && notinuse) { + ret = trig->ops->set_trigger_state(trig, true); + if (ret < 0) + module_put(pf->indio_dev->info->driver_module); + } + + return ret; +} + +static int iio_trigger_dettach_poll_func(struct iio_trigger *trig, + struct iio_poll_func *pf) +{ + int ret = 0; + bool no_other_users + = (bitmap_weight(trig->pool, + CONFIG_IIO_CONSUMERS_PER_TRIGGER) + == 1); + if (trig->ops && trig->ops->set_trigger_state && no_other_users) { + ret = trig->ops->set_trigger_state(trig, false); + if (ret) + goto error_ret; + } + iio_trigger_put_irq(trig, pf->irq); + free_irq(pf->irq, pf); + module_put(pf->indio_dev->info->driver_module); + +error_ret: + return ret; +} + +irqreturn_t iio_pollfunc_store_time(int irq, void *p) +{ + struct iio_poll_func *pf = p; + pf->timestamp = iio_get_time_ns(); + return IRQ_WAKE_THREAD; +} +EXPORT_SYMBOL(iio_pollfunc_store_time); + +struct iio_poll_func +*iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p), + irqreturn_t (*thread)(int irq, void *p), + int type, + struct iio_dev *indio_dev, + const char *fmt, + ...) +{ + va_list vargs; + struct iio_poll_func *pf; + + pf = kmalloc(sizeof *pf, GFP_KERNEL); + if (pf == NULL) + return NULL; + va_start(vargs, fmt); + pf->name = kvasprintf(GFP_KERNEL, fmt, vargs); + va_end(vargs); + if (pf->name == NULL) { + kfree(pf); + return NULL; + } + pf->h = h; + pf->thread = thread; + pf->type = type; + pf->indio_dev = indio_dev; + + return pf; +} +EXPORT_SYMBOL_GPL(iio_alloc_pollfunc); + +void iio_dealloc_pollfunc(struct iio_poll_func *pf) +{ + kfree(pf->name); + kfree(pf); +} +EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc); + +/** + * iio_trigger_read_current() - trigger consumer sysfs query which trigger + * + * For trigger consumers the current_trigger interface allows the trigger + * used by the device to be queried. + **/ +static ssize_t iio_trigger_read_current(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + + if (indio_dev->trig) + return sprintf(buf, "%s\n", indio_dev->trig->name); + return 0; +} + +/** + * iio_trigger_write_current() trigger consumer sysfs set current trigger + * + * For trigger consumers the current_trigger interface allows the trigger + * used for this device to be specified at run time based on the triggers + * name. + **/ +static ssize_t iio_trigger_write_current(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t len) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct iio_trigger *oldtrig = indio_dev->trig; + struct iio_trigger *trig; + int ret; + + mutex_lock(&indio_dev->mlock); + if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) { + mutex_unlock(&indio_dev->mlock); + return -EBUSY; + } + mutex_unlock(&indio_dev->mlock); + + trig = iio_trigger_find_by_name(buf, len); + if (oldtrig == trig) + return len; + + if (trig && indio_dev->info->validate_trigger) { + ret = indio_dev->info->validate_trigger(indio_dev, trig); + if (ret) + return ret; + } + + if (trig && trig->ops && trig->ops->validate_device) { + ret = trig->ops->validate_device(trig, indio_dev); + if (ret) + return ret; + } + + indio_dev->trig = trig; + + if (oldtrig && indio_dev->trig != oldtrig) + iio_put_trigger(oldtrig); + if (indio_dev->trig) + iio_get_trigger(indio_dev->trig); + + return len; +} + +static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR, + iio_trigger_read_current, + iio_trigger_write_current); + +static struct attribute *iio_trigger_consumer_attrs[] = { + &dev_attr_current_trigger.attr, + NULL, +}; + +static const struct attribute_group iio_trigger_consumer_attr_group = { + .name = "trigger", + .attrs = iio_trigger_consumer_attrs, +}; + +static void iio_trig_release(struct device *device) +{ + struct iio_trigger *trig = to_iio_trigger(device); + int i; + + if (trig->subirq_base) { + for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) { + irq_modify_status(trig->subirq_base + i, + IRQ_NOAUTOEN, + IRQ_NOREQUEST | IRQ_NOPROBE); + irq_set_chip(trig->subirq_base + i, + NULL); + irq_set_handler(trig->subirq_base + i, + NULL); + } + + irq_free_descs(trig->subirq_base, + CONFIG_IIO_CONSUMERS_PER_TRIGGER); + } + kfree(trig->name); + kfree(trig); +} + +static struct device_type iio_trig_type = { + .release = iio_trig_release, +}; + +static void iio_trig_subirqmask(struct irq_data *d) +{ + struct irq_chip *chip = irq_data_get_irq_chip(d); + struct iio_trigger *trig + = container_of(chip, + struct iio_trigger, subirq_chip); + trig->subirqs[d->irq - trig->subirq_base].enabled = false; +} + +static void iio_trig_subirqunmask(struct irq_data *d) +{ + struct irq_chip *chip = irq_data_get_irq_chip(d); + struct iio_trigger *trig + = container_of(chip, + struct iio_trigger, subirq_chip); + trig->subirqs[d->irq - trig->subirq_base].enabled = true; +} + +struct iio_trigger *iio_allocate_trigger(const char *fmt, ...) +{ + va_list vargs; + struct iio_trigger *trig; + trig = kzalloc(sizeof *trig, GFP_KERNEL); + if (trig) { + int i; + trig->dev.type = &iio_trig_type; + trig->dev.bus = &iio_bus_type; + device_initialize(&trig->dev); + dev_set_drvdata(&trig->dev, (void *)trig); + + mutex_init(&trig->pool_lock); + trig->subirq_base + = irq_alloc_descs(-1, 0, + CONFIG_IIO_CONSUMERS_PER_TRIGGER, + 0); + if (trig->subirq_base < 0) { + kfree(trig); + return NULL; + } + va_start(vargs, fmt); + trig->name = kvasprintf(GFP_KERNEL, fmt, vargs); + va_end(vargs); + if (trig->name == NULL) { + irq_free_descs(trig->subirq_base, + CONFIG_IIO_CONSUMERS_PER_TRIGGER); + kfree(trig); + return NULL; + } + trig->subirq_chip.name = trig->name; + trig->subirq_chip.irq_mask = &iio_trig_subirqmask; + trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask; + for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) { + irq_set_chip(trig->subirq_base + i, + &trig->subirq_chip); + irq_set_handler(trig->subirq_base + i, + &handle_simple_irq); + irq_modify_status(trig->subirq_base + i, + IRQ_NOREQUEST | IRQ_NOAUTOEN, + IRQ_NOPROBE); + } + get_device(&trig->dev); + } + return trig; +} +EXPORT_SYMBOL(iio_allocate_trigger); + +void iio_free_trigger(struct iio_trigger *trig) +{ + if (trig) + put_device(&trig->dev); +} +EXPORT_SYMBOL(iio_free_trigger); + +void iio_device_register_trigger_consumer(struct iio_dev *indio_dev) +{ + indio_dev->groups[indio_dev->groupcounter++] = + &iio_trigger_consumer_attr_group; +} + +void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev) +{ + /* Clean up and associated but not attached triggers references */ + if (indio_dev->trig) + iio_put_trigger(indio_dev->trig); +} + +int iio_triggered_buffer_postenable(struct iio_dev *indio_dev) +{ + return iio_trigger_attach_poll_func(indio_dev->trig, + indio_dev->pollfunc); +} +EXPORT_SYMBOL(iio_triggered_buffer_postenable); + +int iio_triggered_buffer_predisable(struct iio_dev *indio_dev) +{ + return iio_trigger_dettach_poll_func(indio_dev->trig, + indio_dev->pollfunc); +} +EXPORT_SYMBOL(iio_triggered_buffer_predisable); |