From d96d1337e339521a2bd56dc9d51fef140c1a49ee Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 18 May 2011 14:41:18 +0100 Subject: [PATCH] staging:iio: Add infrastructure for irq_chip based triggers V3: Get rid of separate interrupt pool. This is well handled by irq_get_descs and irq_free_descs. Two functions I simply wasn't aware of previously. Thus the allocation for a given trigger is now handled by core code rather than us reinventing the wheel. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/staging/iio/Kconfig | 7 + drivers/staging/iio/industrialio-trigger.c | 173 +++++++++++++++++---- drivers/staging/iio/trigger.h | 57 ++++++- 3 files changed, 202 insertions(+), 35 deletions(-) diff --git a/drivers/staging/iio/Kconfig b/drivers/staging/iio/Kconfig index 6775bf90e2f..e6235d172cb 100644 --- a/drivers/staging/iio/Kconfig +++ b/drivers/staging/iio/Kconfig @@ -48,6 +48,13 @@ config IIO_TRIGGER 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/industrialio-trigger.c b/drivers/staging/iio/industrialio-trigger.c index 083847c5c2d..5496ee272e2 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 +179,13 @@ 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 +227,31 @@ 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 (pf->thread) { + bool notinuse + = bitmap_empty(trig->pool, + CONFIG_IIO_CONSUMERS_PER_TRIGGER); - 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); + 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 +263,63 @@ 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 +386,22 @@ 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); + } + + irq_free_descs(trig->subirq_base, + CONFIG_IIO_CONSUMERS_PER_TRIGGER); + } kfree(trig); iio_put(); } @@ -345,11 +410,30 @@ 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 +441,41 @@ 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 + = irq_alloc_descs(-1, 0, + CONFIG_IIO_CONSUMERS_PER_TRIGGER, + 0); + 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 c6ab32f74c8..0c44c5efd01 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 + #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_ */