From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH 1/3] irq: If an IRQ is a GPIO, request and configure it Date: Thu, 04 Aug 2011 20:54:59 -0500 Message-ID: <4E3B4D73.9030505@gmail.com> References: <1312498820-2275-1-git-send-email-swarren@nvidia.com> <1312498820-2275-2-git-send-email-swarren@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1312498820-2275-2-git-send-email-swarren@nvidia.com> Sender: linux-mmc-owner@vger.kernel.org To: Stephen Warren Cc: Thomas Gleixner , Mark Brown , Liam Girdwood , Chris Ball , ccross@android.com, olof@lixom.net, alsa-devel@alsa-project.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-tegra@vger.kernel.org On 08/04/2011 06:00 PM, Stephen Warren wrote: > Many IRQs are associated with GPIO pins. When the pin is used as an IRQ, > it can't be used as anything else; it should be requested. Enhance the > core interrupt code to call gpio_request() and gpio_direction_input() for > any IRQ that is also a GPIO. This prevents duplication of these calls in > each driver that uses an IRQ. > > Signed-off-by: Stephen Warren > --- > kernel/irq/manage.c | 23 +++++++++++++++++++++-- > 1 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c > index 0a7840a..6e2db72 100644 > --- a/kernel/irq/manage.c > +++ b/kernel/irq/manage.c > @@ -7,6 +7,7 @@ > * This file contains driver APIs to the irq subsystem. > */ > > +#include > #include > #include > #include > @@ -875,7 +876,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) > struct irqaction *old, **old_ptr; > const char *old_name = NULL; > unsigned long flags, thread_mask = 0; > - int ret, nested, shared = 0; > + int ret, nested, shared = 0, gpio = -1; > cpumask_var_t mask; > > if (!desc) > @@ -978,6 +979,16 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) > old = *old_ptr; > } while (old); > shared = 1; > + } else { > + gpio = irq_to_gpio(irq); If you read the documentation for gpio, it is not recommended to use irq_to_gpio. There's only a handful of users. Part of the problem is it is platform specific and the gpio core cannot convert irq to gpio number. Here is the relevant section: Non-error values returned from irq_to_gpio() would most commonly be used with gpio_get_value(), for example to initialize or update driver state when the IRQ is edge-triggered. Note that some platforms don't support this reverse mapping, so you should avoid using it. Rob > + if (gpio_is_valid(gpio)) { > + ret = gpio_request(gpio, new->name); > + if (ret < 0) > + goto out_mask; > + ret = gpio_direction_input(gpio); > + if (ret < 0) > + goto out_mask; > + } > } > > /* > @@ -1083,6 +1094,8 @@ mismatch: > ret = -EBUSY; > > out_mask: > + if (gpio_is_valid(gpio)) > + gpio_free(gpio); > raw_spin_unlock_irqrestore(&desc->lock, flags); > free_cpumask_var(mask); > > @@ -1127,6 +1140,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) > struct irq_desc *desc = irq_to_desc(irq); > struct irqaction *action, **action_ptr; > unsigned long flags; > + int gpio; > > WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); > > @@ -1165,8 +1179,13 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) > #endif > > /* If this was the last handler, shut down the IRQ line: */ > - if (!desc->action) > + if (!desc->action) { > irq_shutdown(desc); > + /* If the IRQ line is a GPIO, it's no longer in use */ > + gpio = irq_to_gpio(irq); > + if (gpio_is_valid(gpio)) > + gpio_free(gpio); > + } > > #ifdef CONFIG_SMP > /* make sure affinity_hint is cleaned up */ From mboxrd@z Thu Jan 1 00:00:00 1970 From: robherring2@gmail.com (Rob Herring) Date: Thu, 04 Aug 2011 20:54:59 -0500 Subject: [PATCH 1/3] irq: If an IRQ is a GPIO, request and configure it In-Reply-To: <1312498820-2275-2-git-send-email-swarren@nvidia.com> References: <1312498820-2275-1-git-send-email-swarren@nvidia.com> <1312498820-2275-2-git-send-email-swarren@nvidia.com> Message-ID: <4E3B4D73.9030505@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 08/04/2011 06:00 PM, Stephen Warren wrote: > Many IRQs are associated with GPIO pins. When the pin is used as an IRQ, > it can't be used as anything else; it should be requested. Enhance the > core interrupt code to call gpio_request() and gpio_direction_input() for > any IRQ that is also a GPIO. This prevents duplication of these calls in > each driver that uses an IRQ. > > Signed-off-by: Stephen Warren > --- > kernel/irq/manage.c | 23 +++++++++++++++++++++-- > 1 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c > index 0a7840a..6e2db72 100644 > --- a/kernel/irq/manage.c > +++ b/kernel/irq/manage.c > @@ -7,6 +7,7 @@ > * This file contains driver APIs to the irq subsystem. > */ > > +#include > #include > #include > #include > @@ -875,7 +876,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) > struct irqaction *old, **old_ptr; > const char *old_name = NULL; > unsigned long flags, thread_mask = 0; > - int ret, nested, shared = 0; > + int ret, nested, shared = 0, gpio = -1; > cpumask_var_t mask; > > if (!desc) > @@ -978,6 +979,16 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) > old = *old_ptr; > } while (old); > shared = 1; > + } else { > + gpio = irq_to_gpio(irq); If you read the documentation for gpio, it is not recommended to use irq_to_gpio. There's only a handful of users. Part of the problem is it is platform specific and the gpio core cannot convert irq to gpio number. Here is the relevant section: Non-error values returned from irq_to_gpio() would most commonly be used with gpio_get_value(), for example to initialize or update driver state when the IRQ is edge-triggered. Note that some platforms don't support this reverse mapping, so you should avoid using it. Rob > + if (gpio_is_valid(gpio)) { > + ret = gpio_request(gpio, new->name); > + if (ret < 0) > + goto out_mask; > + ret = gpio_direction_input(gpio); > + if (ret < 0) > + goto out_mask; > + } > } > > /* > @@ -1083,6 +1094,8 @@ mismatch: > ret = -EBUSY; > > out_mask: > + if (gpio_is_valid(gpio)) > + gpio_free(gpio); > raw_spin_unlock_irqrestore(&desc->lock, flags); > free_cpumask_var(mask); > > @@ -1127,6 +1140,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) > struct irq_desc *desc = irq_to_desc(irq); > struct irqaction *action, **action_ptr; > unsigned long flags; > + int gpio; > > WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); > > @@ -1165,8 +1179,13 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) > #endif > > /* If this was the last handler, shut down the IRQ line: */ > - if (!desc->action) > + if (!desc->action) { > irq_shutdown(desc); > + /* If the IRQ line is a GPIO, it's no longer in use */ > + gpio = irq_to_gpio(irq); > + if (gpio_is_valid(gpio)) > + gpio_free(gpio); > + } > > #ifdef CONFIG_SMP > /* make sure affinity_hint is cleaned up */