Re: [PATCH v4 1/4] iio: Support triggered events

[Jonathan Cameron <jic23@kernel.org>]

On 20/08/15 20:43, Vladimir Barinov wrote:
> Verified event and buffer polling works concurrently on the same trigger with hi-8435.
> The buffer interface part for hi-8435 was not sent.
> 
> On 20.08.2015 22:37, Vladimir Barinov wrote:
>> Support triggered events.
>>
>> This is useful for chips that don't have their own interrupt sources.
>> It allows to use generic/standalone iio triggers for those drivers.
>>
>> Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Applied with a certain amount of fuzz (the buffers have moved out into
their own directory).

Jonathan
>> ---
>> Changes in version 2:
>> - initially added
>> Changes in version 3:
>> - fixed grammar in patch description
>> - changed license header to match "GNU Public License v2 or later"
>> Changes in version 4:
>> - added pollfunc_event to separate triggering buffer and event
>> interfaces. This allows runnig both from the same trigger
>> - removed 'currentmode' for triggered buffer since useless
>> - renamed parameters of iio_triggered_event_setup
>>
>>   drivers/iio/Kconfig                        |  6 +++
>>   drivers/iio/Makefile                       |  1 +
>>   drivers/iio/industrialio-core.c            |  4 +-
>>   drivers/iio/industrialio-trigger.c         | 12 +++++-
>>   drivers/iio/industrialio-triggered-event.c | 68 ++++++++++++++++++++++++++++++
>>   include/linux/iio/iio.h                    |  3 ++
>>   include/linux/iio/triggered_event.h        | 11 +++++
>>   7 files changed, 101 insertions(+), 4 deletions(-)
>>   create mode 100644 drivers/iio/industrialio-triggered-event.c
>>   create mode 100644 include/linux/iio/triggered_event.h
>>
>> diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
>> index 4011eff..8fcc92f 100644
>> --- a/drivers/iio/Kconfig
>> +++ b/drivers/iio/Kconfig
>> @@ -58,6 +58,12 @@ config IIO_CONSUMERS_PER_TRIGGER
>>       This value controls the maximum number of consumers that a
>>       given trigger may handle. Default is 2.
>>   +config IIO_TRIGGERED_EVENT
>> +    tristate
>> +    select IIO_TRIGGER
>> +    help
>> +      Provides helper functions for setting up triggered events.
>> +
>>   source "drivers/iio/accel/Kconfig"
>>   source "drivers/iio/adc/Kconfig"
>>   source "drivers/iio/amplifiers/Kconfig"
>> diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
>> index 698afc2..40dc13e 100644
>> --- a/drivers/iio/Makefile
>> +++ b/drivers/iio/Makefile
>> @@ -9,6 +9,7 @@ industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
>>   industrialio-$(CONFIG_IIO_BUFFER_CB) += buffer_cb.o
>>     obj-$(CONFIG_IIO_TRIGGERED_BUFFER) += industrialio-triggered-buffer.o
>> +obj-$(CONFIG_IIO_TRIGGERED_EVENT) += industrialio-triggered-event.o
>>   obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
>>     obj-y += accel/
>> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
>> index b3fcc2c..2c3b6a1 100644
>> --- a/drivers/iio/industrialio-core.c
>> +++ b/drivers/iio/industrialio-core.c
>> @@ -962,7 +962,7 @@ static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
>>   static void iio_dev_release(struct device *device)
>>   {
>>       struct iio_dev *indio_dev = dev_to_iio_dev(device);
>> -    if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
>> +    if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
>>           iio_device_unregister_trigger_consumer(indio_dev);
>>       iio_device_unregister_eventset(indio_dev);
>>       iio_device_unregister_sysfs(indio_dev);
>> @@ -1241,7 +1241,7 @@ int iio_device_register(struct iio_dev *indio_dev)
>>               "Failed to register event set\n");
>>           goto error_free_sysfs;
>>       }
>> -    if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
>> +    if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
>>           iio_device_register_trigger_consumer(indio_dev);
>>         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
>> diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
>> index 570606c..ae2806a 100644
>> --- a/drivers/iio/industrialio-trigger.c
>> +++ b/drivers/iio/industrialio-trigger.c
>> @@ -366,10 +366,18 @@ static ssize_t iio_trigger_write_current(struct device *dev,
>>         indio_dev->trig = trig;
>>   -    if (oldtrig)
>> +    if (oldtrig) {
>> +        if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
>> +            iio_trigger_detach_poll_func(oldtrig,
>> +                             indio_dev->pollfunc_event);
>>           iio_trigger_put(oldtrig);
>> -    if (indio_dev->trig)
>> +    }
>> +    if (indio_dev->trig) {
>>           iio_trigger_get(indio_dev->trig);
>> +        if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
>> +            iio_trigger_attach_poll_func(indio_dev->trig,
>> +                             indio_dev->pollfunc_event);
>> +    }
>>         return len;
>>   }
>> diff --git a/drivers/iio/industrialio-triggered-event.c b/drivers/iio/industrialio-triggered-event.c
>> new file mode 100644
>> index 0000000..8cc254f
>> --- /dev/null
>> +++ b/drivers/iio/industrialio-triggered-event.c
>> @@ -0,0 +1,68 @@
>> +/*
>> + * Copyright (C) 2015 Cogent Embedded, Inc.
>> + *
>> + * This program is free software; you can redistribute  it and/or modify it
>> + * under  the terms of  the GNU General  Public License as published by the
>> + * Free Software Foundation;  either version 2 of the  License, or (at your
>> + * option) any later version.
>> + */
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/export.h>
>> +#include <linux/module.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/triggered_event.h>
>> +#include <linux/iio/trigger_consumer.h>
>> +
>> +/**
>> + * iio_triggered_event_setup() - Setup pollfunc_event for triggered event
>> + * @indio_dev:    IIO device structure
>> + * @h:        Function which will be used as pollfunc_event top half
>> + * @thread:    Function which will be used as pollfunc_event bottom half
>> + *
>> + * This function combines some common tasks which will normally be performed
>> + * when setting up a triggered event. It will allocate the pollfunc_event and
>> + * set mode to use it for triggered event.
>> + *
>> + * Before calling this function the indio_dev structure should already be
>> + * completely initialized, but not yet registered. In practice this means that
>> + * this function should be called right before iio_device_register().
>> + *
>> + * To free the resources allocated by this function call
>> + * iio_triggered_event_cleanup().
>> + */
>> +int iio_triggered_event_setup(struct iio_dev *indio_dev,
>> +                  irqreturn_t (*h)(int irq, void *p),
>> +                  irqreturn_t (*thread)(int irq, void *p))
>> +{
>> +    indio_dev->pollfunc_event = iio_alloc_pollfunc(h,
>> +                               thread,
>> +                               IRQF_ONESHOT,
>> +                               indio_dev,
>> +                               "%s_consumer%d",
>> +                               indio_dev->name,
>> +                               indio_dev->id);
>> +    if (indio_dev->pollfunc_event == NULL)
>> +        return -ENOMEM;
>> +
>> +    /* Flag that events polling is possible */
>> +    indio_dev->modes |= INDIO_EVENT_TRIGGERED;
>> +
>> +    return 0;
>> +}
>> +EXPORT_SYMBOL(iio_triggered_event_setup);
>> +
>> +/**
>> + * iio_triggered_event_cleanup() - Free resources allocated by iio_triggered_event_setup()
>> + * @indio_dev: IIO device structure
>> + */
>> +void iio_triggered_event_cleanup(struct iio_dev *indio_dev)
>> +{
>> +    indio_dev->modes &= ~INDIO_EVENT_TRIGGERED;
>> +    iio_dealloc_pollfunc(indio_dev->pollfunc_event);
>> +}
>> +EXPORT_SYMBOL(iio_triggered_event_cleanup);
>> +
>> +MODULE_AUTHOR("Vladimir Barinov");
>> +MODULE_DESCRIPTION("IIO helper functions for setting up triggered events");
>> +MODULE_LICENSE("GPL");
>> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
>> index 7bb7f67..19c94c9 100644
>> --- a/include/linux/iio/iio.h
>> +++ b/include/linux/iio/iio.h
>> @@ -294,6 +294,7 @@ static inline s64 iio_get_time_ns(void)
>>   #define INDIO_BUFFER_TRIGGERED        0x02
>>   #define INDIO_BUFFER_SOFTWARE        0x04
>>   #define INDIO_BUFFER_HARDWARE        0x08
>> +#define INDIO_EVENT_TRIGGERED        0x10
>>     #define INDIO_ALL_BUFFER_MODES                    \
>>       (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE | INDIO_BUFFER_SOFTWARE)
>> @@ -457,6 +458,7 @@ struct iio_buffer_setup_ops {
>>    * @scan_index_timestamp:[INTERN] cache of the index to the timestamp
>>    * @trig:        [INTERN] current device trigger (buffer modes)
>>    * @pollfunc:        [DRIVER] function run on trigger being received
>> + * @pollfunc_event:    [DRIVER] function run on events trigger being received
>>    * @channels:        [DRIVER] channel specification structure table
>>    * @num_channels:    [DRIVER] number of channels specified in @channels.
>>    * @channel_attr_list:    [INTERN] keep track of automatically created channel
>> @@ -495,6 +497,7 @@ struct iio_dev {
>>       unsigned            scan_index_timestamp;
>>       struct iio_trigger        *trig;
>>       struct iio_poll_func        *pollfunc;
>> +    struct iio_poll_func        *pollfunc_event;
>>         struct iio_chan_spec const    *channels;
>>       int                num_channels;
>> diff --git a/include/linux/iio/triggered_event.h b/include/linux/iio/triggered_event.h
>> new file mode 100644
>> index 0000000..8fe8537
>> --- /dev/null
>> +++ b/include/linux/iio/triggered_event.h
>> @@ -0,0 +1,11 @@
>> +#ifndef _LINUX_IIO_TRIGGERED_EVENT_H_
>> +#define _LINUX_IIO_TRIGGERED_EVENT_H_
>> +
>> +#include <linux/interrupt.h>
>> +
>> +int iio_triggered_event_setup(struct iio_dev *indio_dev,

>> +    irqreturn_t (*h)(int irq, void *p),
>> +    irqreturn_t (*thread)(int irq, void *p));
>> +void iio_triggered_event_cleanup(struct iio_dev *indio_dev);
>> +
>> +#endif
> 
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