Change of plan here.
It's perfectly possible, (but somewhat under utilized) to call irq_alloc_descs
to give us a dynamically allocated range of irq's. It may be dependant on sparse irq
though so will need to look into that or provide alternative method such
as this one.
> fix to merge back for the incorrect multiple trigger handling
>
> V2: Stop silly name duplication.
> Move pool handling to industrialio-trigger as that is the only user.
> Changed over to using irq_modify_status rather than the arm
> specific set_irq_flags as per Thomas Gleixner's suggestion.
>
> Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxx>
> ---
> drivers/staging/Makefile | 2 +-
> drivers/staging/iio/Kconfig | 12 ++
> drivers/staging/iio/Makefile | 2 +
> drivers/staging/iio/iio-board-info.h | 24 +++
> drivers/staging/iio/iio-core.h | 13 ++
> drivers/staging/iio/industrialio-board-info.c | 25 +++
> drivers/staging/iio/industrialio-trigger.c | 200 +++++++++++++++++++++----
> drivers/staging/iio/trigger.h | 57 +++++++-
> 8 files changed, 298 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
> index eb93012..0955c7c 100644
> --- a/drivers/staging/Makefile
> +++ b/drivers/staging/Makefile
> @@ -41,7 +41,7 @@ obj-$(CONFIG_VT6656) += vt6656/
> obj-$(CONFIG_HYPERV) += hv/
> obj-$(CONFIG_VME_BUS) += vme/
> obj-$(CONFIG_DX_SEP) += sep/
> -obj-$(CONFIG_IIO) += iio/
> +obj-y += iio/
> obj-$(CONFIG_CS5535_GPIO) += cs5535_gpio/
> obj-$(CONFIG_ZRAM) += zram/
> obj-$(CONFIG_XVMALLOC) += zram/
> diff --git a/drivers/staging/iio/Kconfig b/drivers/staging/iio/Kconfig
> index 6775bf9..df9aa08 100644
> --- a/drivers/staging/iio/Kconfig
> +++ b/drivers/staging/iio/Kconfig
> @@ -12,6 +12,10 @@ menuconfig IIO
> Documentation/industrialio for more information.
> if IIO
>
> +config IIO_BOARDINFO
> + boolean
> + default y
> +
> config IIO_RING_BUFFER
> bool "Enable ring buffer support within IIO"
> help
> @@ -42,12 +46,20 @@ endif # IIO_RINGBUFFER
>
> config IIO_TRIGGER
> boolean "Enable triggered sampling support"
> + depends on IIO_BOARDINFO
> help
> Provides IIO core support for triggers. Currently these
> are used to initialize capture of samples to push into
> ring buffers. The triggers are effectively a 'capture
> data now' interrupt.
>
> +config IIO_CONSUMERS_PER_TRIGGER
> + int "Maximum number of consumers per trigger"
> + depends on IIO_TRIGGER
> + default "2"
> + help
> + This value controls the maximum number of consumers that a
> + given trigger may handle. Default is 2.
>
> source "drivers/staging/iio/accel/Kconfig"
> source "drivers/staging/iio/adc/Kconfig"
> diff --git a/drivers/staging/iio/Makefile b/drivers/staging/iio/Makefile
> index bb5c95c..37b4d12 100644
> --- a/drivers/staging/iio/Makefile
> +++ b/drivers/staging/iio/Makefile
> @@ -2,6 +2,8 @@
> # Makefile for the industrial I/O core.
> #
>
> +obj-$(CONFIG_IIO_BOARDINFO) += industrialio-board-info.o
> +
> obj-$(CONFIG_IIO) += industrialio.o
> industrialio-y := industrialio-core.o
> industrialio-$(CONFIG_IIO_RING_BUFFER) += industrialio-ring.o
> diff --git a/drivers/staging/iio/iio-board-info.h b/drivers/staging/iio/iio-board-info.h
> new file mode 100644
> index 0000000..c608a4d
> --- /dev/null
> +++ b/drivers/staging/iio/iio-board-info.h
> @@ -0,0 +1,24 @@
> +/*
> + * Board information for IIO.
> + *
> + * Copyright (c) 2011 Jonathan Cameron <jic23@xxxxxxxxx>
> + *
> + * 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.
> + */
> +
> +#ifdef CONFIG_IIO_BOARDINFO
> +
> +/**
> + * iio_set_irq_pool() - provid iio with a pool of virtaul interrupts to use
> + * @start: start of the pool
> + * @num: number of interupts in the pool
> + **/
> +void iio_set_irq_pool(int start, int num);
> +
> +#else
> +
> +static inline void iio_set_irq_pool(int start, int num) {};
> +
> +#endif
> diff --git a/drivers/staging/iio/iio-core.h b/drivers/staging/iio/iio-core.h
> new file mode 100644
> index 0000000..2c4f433
> --- /dev/null
> +++ b/drivers/staging/iio/iio-core.h
> @@ -0,0 +1,13 @@
> +/*
> + * IIO core header. Should never be included by drivers.
> + *
> + * Copyright (c) 2011 Jonathan Cameron <jic23@xxxxxxxxx>
> + *
> + * 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.
> + */
> +
> +#define IIO_MAX_POOL 128
> +extern int __iio_irqstart;
> +extern int __iio_irqnum;
> diff --git a/drivers/staging/iio/industrialio-board-info.c b/drivers/staging/iio/industrialio-board-info.c
> new file mode 100644
> index 0000000..28f9156
> --- /dev/null
> +++ b/drivers/staging/iio/industrialio-board-info.c
> @@ -0,0 +1,25 @@
> +/* IIO Board info
> + *
> + * Copyright (c) 2011 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/module.h>
> +#include <linux/kernel.h>
> +#include "iio-core.h"
> +
> +int __iio_irqstart;
> +EXPORT_SYMBOL(__iio_irqstart);
> +int __iio_irqnum;
> +EXPORT_SYMBOL(__iio_irqnum);
> +
> +void __init iio_set_irq_pool(int start, int num)
> +{
> + __iio_irqstart = start;
> + __iio_irqnum = num;
> + if (num > IIO_MAX_POOL)
> + __iio_irqnum = IIO_MAX_POOL;
> +}
> diff --git a/drivers/staging/iio/industrialio-trigger.c b/drivers/staging/iio/industrialio-trigger.c
> index 083847c..9ccc789 100644
> --- a/drivers/staging/iio/industrialio-trigger.c
> +++ b/drivers/staging/iio/industrialio-trigger.c
> @@ -19,6 +19,7 @@
> #include "iio.h"
> #include "trigger.h"
> #include "trigger_consumer.h"
> +#include "iio-core.h"
>
> /* RFC - Question of approach
> * Make the common case (single sensor single trigger)
> @@ -38,6 +39,31 @@ static DEFINE_SPINLOCK(iio_trigger_idr_lock);
> static LIST_HEAD(iio_trigger_list);
> static DEFINE_MUTEX(iio_trigger_list_lock);
>
> +static DEFINE_MUTEX(iio_irq_pool_lock);
> +static unsigned long iio_irq_pool_mask[BITS_TO_LONGS(IIO_MAX_POOL)] = {};
> +
> +static int iio_irq_pool_get_range(int num)
> +{
> + int ret;
> +
> + mutex_lock(&iio_irq_pool_lock);
> + ret = bitmap_find_free_region(iio_irq_pool_mask,
> + __iio_irqnum, ilog2(num));
> + if (ret >= 0)
> + ret += __iio_irqstart;
> + mutex_unlock(&iio_irq_pool_lock);
> +
> + return ret;
> +}
> +
> +static void iio_irq_pool_put_range(int start, int num)
> +{
> + mutex_lock(&iio_irq_pool_lock);
> + bitmap_release_region(iio_irq_pool_mask,
> + start - __iio_irqstart, ilog2(num));
> + mutex_unlock(&iio_irq_pool_lock);
> +}
> +
> /**
> * iio_trigger_register_sysfs() - create a device for this trigger
> * @trig_info: the trigger
> @@ -163,6 +189,7 @@ static struct iio_trigger *iio_trigger_find_by_name(const char *name,
>
> void iio_trigger_poll(struct iio_trigger *trig, s64 time)
> {
> + int i;
> struct iio_poll_func *pf_cursor;
>
> list_for_each_entry(pf_cursor, &trig->pollfunc_list, list) {
> @@ -178,6 +205,13 @@ void iio_trigger_poll(struct iio_trigger *trig, s64 time)
> trig->use_count++;
> }
> }
> + 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);
>
> @@ -219,16 +253,31 @@ int iio_trigger_attach_poll_func(struct iio_trigger *trig,
> int ret = 0;
> unsigned long flags;
>
> - spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
> - list_add_tail(&pf->list, &trig->pollfunc_list);
> - spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);
> -
> - if (trig->set_trigger_state)
> - ret = trig->set_trigger_state(trig, true);
> - if (ret) {
> - printk(KERN_ERR "set trigger state failed\n");
> - list_del(&pf->list);
> + if (pf->thread) {
> + bool notinuse
> + = bitmap_empty(trig->pool,
> + CONFIG_IIO_CONSUMERS_PER_TRIGGER);
> +
> + pf->irq = iio_trigger_get_irq(trig);
> + ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
> + pf->type, pf->name,
> + pf);
> + if (trig->set_trigger_state && notinuse) {
> + ret = trig->set_trigger_state(trig, true);
> + } else {
> + spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
> + list_add_tail(&pf->list, &trig->pollfunc_list);
> + spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);
> +
> + if (trig->set_trigger_state)
> + ret = trig->set_trigger_state(trig, true);
> + }
> + if (ret) {
> + printk(KERN_ERR "set trigger state failed\n");
> + list_del(&pf->list);
> + }
> }
> +
> return ret;
> }
> EXPORT_SYMBOL(iio_trigger_attach_poll_func);
> @@ -240,37 +289,63 @@ int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
> unsigned long flags;
> int ret = -EINVAL;
>
> - spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
> - list_for_each_entry(pf_cursor, &trig->pollfunc_list, list)
> - if (pf_cursor == pf) {
> - ret = 0;
> - break;
> - }
> - if (!ret) {
> - if (list_is_singular(&trig->pollfunc_list)
> - && trig->set_trigger_state) {
> - spin_unlock_irqrestore(&trig->pollfunc_list_lock,
> - flags);
> - /* May sleep hence cannot hold the spin lock */
> + if (pf->thread) {
> + bool no_other_users
> + = (bitmap_weight(trig->pool,
> + CONFIG_IIO_CONSUMERS_PER_TRIGGER)
> + == 1);
> + if (trig->set_trigger_state && no_other_users) {
> ret = trig->set_trigger_state(trig, false);
> if (ret)
> goto error_ret;
> - spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
> + } else
> + ret = 0;
> + iio_trigger_put_irq(trig, pf->irq);
> + free_irq(pf->irq, pf);
> + } else {
> + spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
> + list_for_each_entry(pf_cursor, &trig->pollfunc_list, list)
> + if (pf_cursor == pf) {
> + ret = 0;
> + break;
> + }
> + if (!ret) {
> + if (list_is_singular(&trig->pollfunc_list)
> + && trig->set_trigger_state) {
> + spin_unlock_irqrestore(&trig
> + ->pollfunc_list_lock,
> + flags);
> + /* May sleep hence cannot hold the spin lock */
> + ret = trig->set_trigger_state(trig, false);
> + if (ret)
> + goto error_ret;
> + spin_lock_irqsave(&trig->pollfunc_list_lock,
> + flags);
> + }
> + /*
> + * Now we can delete safe in the knowledge that, if
> + * this is the last pollfunc then we have disabled
> + * the trigger anyway and so nothing should be able
> + * to call the pollfunc.
> + */
> + list_del(&pf_cursor->list);
> }
> - /*
> - * Now we can delete safe in the knowledge that, if this is
> - * the last pollfunc then we have disabled the trigger anyway
> - * and so nothing should be able to call the pollfunc.
> - */
> - list_del(&pf_cursor->list);
> + spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);
> }
> - spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);
>
> error_ret:
> return ret;
> }
> EXPORT_SYMBOL(iio_trigger_dettach_poll_func);
>
> +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);
> +
> /**
> * iio_trigger_read_currrent() - trigger consumer sysfs query which trigger
> *
> @@ -337,6 +412,22 @@ static const struct attribute_group iio_trigger_consumer_attr_group = {
> 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);
> + }
> +
> + iio_irq_pool_put_range(trig->subirq_base,
> + CONFIG_IIO_CONSUMERS_PER_TRIGGER);
> + }
> kfree(trig);
> iio_put();
> }
> @@ -345,11 +436,30 @@ static struct device_type iio_trig_type = {
> .release = iio_trig_release,
> };
>
> -struct iio_trigger *iio_allocate_trigger(void)
> +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_named(const char *name)
> {
> 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);
> @@ -357,10 +467,40 @@ struct iio_trigger *iio_allocate_trigger(void)
> spin_lock_init(&trig->pollfunc_list_lock);
> INIT_LIST_HEAD(&trig->list);
> INIT_LIST_HEAD(&trig->pollfunc_list);
> +
> + if (name) {
> + mutex_init(&trig->pool_lock);
> + trig->subirq_base
> + = iio_irq_pool_get_range(
> + CONFIG_IIO_CONSUMERS_PER_TRIGGER);
> + if (trig->subirq_base < 0) {
> + kfree(trig);
> + return NULL;
> + }
> + trig->name = name;
> + trig->subirq_chip.name = 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);
> + }
> + }
> iio_get();
> }
> return trig;
> }
> +EXPORT_SYMBOL(iio_allocate_trigger_named);
> +
> +struct iio_trigger *iio_allocate_trigger(void)
> +{
> + return iio_allocate_trigger_named(NULL);
> +}
> EXPORT_SYMBOL(iio_allocate_trigger);
>
> void iio_free_trigger(struct iio_trigger *trig)
> diff --git a/drivers/staging/iio/trigger.h b/drivers/staging/iio/trigger.h
> index c6ab32f..0c44c5e 100644
> --- a/drivers/staging/iio/trigger.h
> +++ b/drivers/staging/iio/trigger.h
> @@ -6,9 +6,15 @@
> * under the terms of the GNU General Public License version 2 as published by
> * the Free Software Foundation.
> */
> +#include <linux/irq.h>
> +
> #ifndef _IIO_TRIGGER_H_
> #define _IIO_TRIGGER_H_
>
> +struct iio_subirq {
> + bool enabled;
> +};
> +
> /**
> * struct iio_trigger - industrial I/O trigger device
> *
> @@ -43,6 +49,13 @@ struct iio_trigger {
>
> int (*set_trigger_state)(struct iio_trigger *trig, bool state);
> int (*try_reenable)(struct iio_trigger *trig);
> +
> + struct irq_chip subirq_chip;
> + int subirq_base;
> +
> + struct iio_subirq subirqs[CONFIG_IIO_CONSUMERS_PER_TRIGGER];
> + unsigned long pool[BITS_TO_LONGS(CONFIG_IIO_CONSUMERS_PER_TRIGGER)];
> + struct mutex pool_lock;
> };
>
> static inline struct iio_trigger *to_iio_trigger(struct device *d)
> @@ -114,6 +127,27 @@ int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
> void iio_trigger_poll(struct iio_trigger *trig, s64 time);
> void iio_trigger_notify_done(struct iio_trigger *trig);
>
> +static inline 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 inline 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);
> +};
> +
> /**
> * struct iio_poll_func - poll function pair
> *
> @@ -125,11 +159,14 @@ void iio_trigger_notify_done(struct iio_trigger *trig);
> * @poll_func_main: function in here is run after all immediates.
> * Reading from sensor etc typically involves
> * scheduling from here.
> - *
> - * The two stage approach used here is only important when multiple sensors are
> - * being triggered by a single trigger. This really comes into its own with
> - * simultaneous sampling devices where a simple latch command can be used to
> - * make the device store the values on all inputs.
> + * @h: the function that is actually run on trigger
> + * @thread: threaded interrupt part
> + * @type: the type of interrupt (basically if oneshot)
> + * @irq: the corresponding irq as allocated from the
> + * trigger pool
> + * @timestamp: some devices need a timestamp grabbed as soon
> + * as possible after the trigger - hence handler
> + * passes it via here.
> **/
> struct iio_poll_func {
> struct list_head list;
> @@ -137,12 +174,20 @@ struct iio_poll_func {
> void (*poll_func_immediate)(struct iio_dev *indio_dev);
> void (*poll_func_main)(struct iio_dev *private_data, s64 time);
>
> + irqreturn_t (*h)(int irq, void *p);
> + irqreturn_t (*thread)(int irq, void *p);
> + int type;
> + char *name;
> + int irq;
> + s64 timestamp;
> };
>
> int iio_alloc_pollfunc(struct iio_dev *indio_dev,
> void (*immediate)(struct iio_dev *indio_dev),
> void (*main)(struct iio_dev *private_data, s64 time));
>
> +irqreturn_t iio_pollfunc_store_time(int irq, void *p);
> +
> /*
> * Two functions for common case where all that happens is a pollfunc
> * is attached and detached from a trigger
> @@ -151,7 +196,7 @@ int iio_triggered_ring_postenable(struct iio_dev *indio_dev);
> int iio_triggered_ring_predisable(struct iio_dev *indio_dev);
>
> struct iio_trigger *iio_allocate_trigger(void);
> -
> +struct iio_trigger *iio_allocate_trigger_named(const char *name);
> void iio_free_trigger(struct iio_trigger *trig);
>
> #endif /* _IIO_TRIGGER_H_ */
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