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Subject[PATCH 15/21] staging:iio: Add infrastructure for irq_chip based triggers
Date
---
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/iio.h | 13 ++
drivers/staging/iio/industrialio-board-info.c | 25 ++++
drivers/staging/iio/industrialio-core.c | 28 +++++
drivers/staging/iio/industrialio-trigger.c | 146 ++++++++++++++++++++-----
drivers/staging/iio/trigger.h | 40 +++++++-
10 files changed, 275 insertions(+), 30 deletions(-)
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index cfd13cd..ee7594c 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -42,7 +42,7 @@ obj-$(CONFIG_HYPERV) += hv/
obj-$(CONFIG_VME_BUS) += vme/
obj-$(CONFIG_MRST_RAR_HANDLER) += memrar/
obj-$(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@cam.ac.uk>
+ *
+ * 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@cam.ac.uk>
+ *
+ * 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/iio.h b/drivers/staging/iio/iio.h
index fb6caae..add0659 100644
--- a/drivers/staging/iio/iio.h
+++ b/drivers/staging/iio/iio.h
@@ -304,6 +304,19 @@ extern dev_t iio_devt;
extern struct bus_type iio_bus_type;

/**
+ * iio_irq_pool_get_range() - get a set of irqs from the pool
+ * @num: number of interrupts requested
+ **/
+int iio_irq_pool_get_range(int num);
+
+/**
+ * iio_irq_pool_put_range()
+ * @start: first irq to return to the pool
+ * @num: number to return
+ **/
+void iio_irq_pool_put_range(int start, int num);
+
+/**
* iio_put_device() - reference counted deallocation of struct device
* @dev: the iio_device containing the device
**/
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-core.c b/drivers/staging/iio/industrialio-core.c
index 0473f55..39b987d 100644
--- a/drivers/staging/iio/industrialio-core.c
+++ b/drivers/staging/iio/industrialio-core.c
@@ -23,6 +23,7 @@
#include <linux/cdev.h>
#include <linux/slab.h>
#include "iio.h"
+#include "iio-core.h"
#include "trigger_consumer.h"

#define IIO_ID_PREFIX "device"
@@ -35,6 +36,33 @@ static DEFINE_IDA(iio_chrdev_ida);
/* Lock used to protect both of the above */
static DEFINE_SPINLOCK(iio_ida_lock);

+static DEFINE_MUTEX(iio_irq_pool_lock);
+static unsigned long iio_irq_pool_mask[BITS_TO_LONGS(IIO_MAX_POOL)] = {};
+
+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;
+}
+EXPORT_SYMBOL(iio_irq_pool_get_range);
+
+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);
+}
+EXPORT_SYMBOL(iio_irq_pool_put_range);
+
dev_t iio_devt;
EXPORT_SYMBOL(iio_devt);

diff --git a/drivers/staging/iio/industrialio-trigger.c b/drivers/staging/iio/industrialio-trigger.c
index 083847c..8100822 100644
--- a/drivers/staging/iio/industrialio-trigger.c
+++ b/drivers/staging/iio/industrialio-trigger.c
@@ -163,6 +163,7 @@ 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 +179,11 @@ void iio_trigger_poll(struct iio_trigger *trig, s64 time)
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 +225,23 @@ 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 (pf->handler) {
+ pf->irq = iio_trigger_get_irq(trig);
+ ret = request_threaded_irq(pf->irq, NULL, pf->handler,
+ pf->type, pf->name,
+ pf);
+ } 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);
@@ -240,31 +253,42 @@ 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 (pf->handler) {
+ ret = trig->set_trigger_state(trig, false);
+ if (ret)
+ goto error_ret;
+ 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);
}
- 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);
+ spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);
}
- spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);

error_ret:
return ret;
@@ -337,6 +361,21 @@ 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++) {
+ set_irq_flags(trig->subirq_base + i, 0);
+ irq_set_chip(trig->subirq_base + i,
+ NULL);
+ irq_set_handler(trig->subirq_base + i,
+ NULL);
+ }
+
+ kfree(trig->subirq_chip.name);
+ iio_irq_pool_put_range(trig->subirq_base,
+ CONFIG_IIO_CONSUMERS_PER_TRIGGER);
+ }
kfree(trig);
iio_put();
}
@@ -345,11 +384,30 @@ 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 +415,42 @@ 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->subirq_chip.name = kstrdup(name, GFP_KERNEL);
+ if (trig->subirq_chip.name == NULL) {
+ kfree(trig);
+ return NULL;
+ }
+ 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);
+ set_irq_flags(trig->subirq_base + i,
+ IRQF_VALID);
+ }
+ }
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..2e52004 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
*
@@ -137,6 +171,10 @@ 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 (*handler)(int irq, void *p);
+ int type;
+ char *name;
+ int irq;
};

int iio_alloc_pollfunc(struct iio_dev *indio_dev,
@@ -151,7 +189,7 @@ 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_ */
--
1.7.3.4


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