diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2014-03-08 08:59:58 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2014-03-12 16:00:24 +0100 |
| commit | c1bacbae8192dd2a9ebadd22d793b68054f6c6e5 (patch) | |
| tree | a2d402e83d75c77a390e47c0150078230bc0101a | |
| parent | fa389e220254c69ffae0d403eac4146171062d08 (diff) | |
genirq: Provide irq_request/release_resources chip callbacks
For certain irq types, e.g. gpios, it's necessary to request resources
before starting up the irq.
This might fail so we cannot use the irq_startup() callback because we
might call the irq_set_type() callback before that which does not make
sense when the resource is not available. Calling irq_startup() before
irq_set_type() can lead to spurious interrupts which is not desired
either.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1403080857160.18573@ionos.tec.linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | include/linux/irq.h | 6 | ||||
| -rw-r--r-- | kernel/irq/manage.c | 28 |
2 files changed, 33 insertions, 1 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h index 7dc10036eff5..e675971bdc3f 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -303,6 +303,10 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d) * @irq_pm_shutdown: function called from core code on shutdown once per chip * @irq_calc_mask: Optional function to set irq_data.mask for special cases * @irq_print_chip: optional to print special chip info in show_interrupts + * @irq_request_resources: optional to request resources before calling + * any other callback related to this irq + * @irq_release_resources: optional to release resources acquired with + * irq_request_resources * @flags: chip specific flags */ struct irq_chip { @@ -336,6 +340,8 @@ struct irq_chip { void (*irq_calc_mask)(struct irq_data *data); void (*irq_print_chip)(struct irq_data *data, struct seq_file *p); + int (*irq_request_resources)(struct irq_data *data); + void (*irq_release_resources)(struct irq_data *data); unsigned long flags; }; diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index d3bf660cb57f..5d35cbe22896 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -896,6 +896,23 @@ static void irq_setup_forced_threading(struct irqaction *new) } } +static int irq_request_resources(struct irq_desc *desc) +{ + struct irq_data *d = &desc->irq_data; + struct irq_chip *c = d->chip; + + return c->irq_request_resources ? c->irq_request_resources(d) : 0; +} + +static void irq_release_resources(struct irq_desc *desc) +{ + struct irq_data *d = &desc->irq_data; + struct irq_chip *c = d->chip; + + if (c->irq_release_resources) + c->irq_release_resources(d); +} + /* * Internal function to register an irqaction - typically used to * allocate special interrupts that are part of the architecture. @@ -1091,6 +1108,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) } if (!shared) { + ret = irq_request_resources(desc); + if (ret) { + pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n", + new->name, irq, desc->irq_data.chip->name); + goto out_mask; + } + init_waitqueue_head(&desc->wait_for_threads); /* Setup the type (level, edge polarity) if configured: */ @@ -1261,8 +1285,10 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) *action_ptr = action->next; /* If this was the last handler, shut down the IRQ line: */ - if (!desc->action) + if (!desc->action) { irq_shutdown(desc); + irq_release_resources(desc); + } #ifdef CONFIG_SMP /* make sure affinity_hint is cleaned up */ |