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path: root/drivers/gpio/gpiolib.c
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Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r--drivers/gpio/gpiolib.c101
1 files changed, 83 insertions, 18 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index f48817d97480..d9c9cb4665db 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1363,6 +1363,11 @@ void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
int parent_irq,
irq_flow_handler_t parent_handler)
{
+ if (gpiochip->can_sleep) {
+ chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
+ return;
+ }
+
irq_set_chained_handler(parent_irq, parent_handler);
/*
* The parent irqchip is already using the chip_data for this
@@ -1372,6 +1377,12 @@ void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
}
EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
+/*
+ * This lock class tells lockdep that GPIO irqs are in a different
+ * category than their parents, so it won't report false recursion.
+ */
+static struct lock_class_key gpiochip_irq_lock_class;
+
/**
* gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
* @d: the irqdomain used by this irqchip
@@ -1388,22 +1399,35 @@ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
struct gpio_chip *chip = d->host_data;
irq_set_chip_data(irq, chip);
+ irq_set_lockdep_class(irq, &gpiochip_irq_lock_class);
irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
+ /* Chips that can sleep need nested thread handlers */
+ if (chip->can_sleep)
+ irq_set_nested_thread(irq, 1);
#ifdef CONFIG_ARM
set_irq_flags(irq, IRQF_VALID);
#else
irq_set_noprobe(irq);
#endif
- irq_set_irq_type(irq, chip->irq_default_type);
+ /*
+ * No set-up of the hardware will happen if IRQ_TYPE_NONE
+ * is passed as default type.
+ */
+ if (chip->irq_default_type != IRQ_TYPE_NONE)
+ irq_set_irq_type(irq, chip->irq_default_type);
return 0;
}
static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
{
+ struct gpio_chip *chip = d->host_data;
+
#ifdef CONFIG_ARM
set_irq_flags(irq, 0);
#endif
+ if (chip->can_sleep)
+ irq_set_nested_thread(irq, 0);
irq_set_chip_and_handler(irq, NULL, NULL);
irq_set_chip_data(irq, NULL);
}
@@ -1471,7 +1495,8 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
* @first_irq: if not dynamically assigned, the base (first) IRQ to
* allocate gpiochip irqs from
* @handler: the irq handler to use (often a predefined irq core function)
- * @type: the default type for IRQs on this irqchip
+ * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
+ * to have the core avoid setting up any default type in the hardware.
*
* This function closely associates a certain irqchip with a certain
* gpiochip, providing an irq domain to translate the local IRQs to
@@ -2571,22 +2596,27 @@ void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
mutex_unlock(&gpio_lookup_lock);
}
-#ifdef CONFIG_OF
static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
unsigned int idx,
enum gpio_lookup_flags *flags)
{
+ static const char *suffixes[] = { "gpios", "gpio" };
char prop_name[32]; /* 32 is max size of property name */
enum of_gpio_flags of_flags;
struct gpio_desc *desc;
+ unsigned int i;
- if (con_id)
- snprintf(prop_name, 32, "%s-gpios", con_id);
- else
- snprintf(prop_name, 32, "gpios");
+ for (i = 0; i < ARRAY_SIZE(suffixes); i++) {
+ if (con_id)
+ snprintf(prop_name, 32, "%s-%s", con_id, suffixes[i]);
+ else
+ snprintf(prop_name, 32, "%s", suffixes[i]);
- desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
- &of_flags);
+ desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
+ &of_flags);
+ if (!IS_ERR(desc))
+ break;
+ }
if (IS_ERR(desc))
return desc;
@@ -2596,14 +2626,6 @@ static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
return desc;
}
-#else
-static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
- unsigned int idx,
- enum gpio_lookup_flags *flags)
-{
- return ERR_PTR(-ENODEV);
-}
-#endif
static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
unsigned int idx,
@@ -2701,7 +2723,7 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
}
/**
- * gpio_get - obtain a GPIO for a given GPIO function
+ * gpiod_get - obtain a GPIO for a given GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
*
@@ -2716,6 +2738,22 @@ struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id)
EXPORT_SYMBOL_GPL(gpiod_get);
/**
+ * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
+ * @dev: GPIO consumer, can be NULL for system-global GPIOs
+ * @con_id: function within the GPIO consumer
+ *
+ * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
+ * the requested function it will return NULL. This is convenient for drivers
+ * that need to handle optional GPIOs.
+ */
+struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
+ const char *con_id)
+{
+ return gpiod_get_index_optional(dev, con_id, 0);
+}
+EXPORT_SYMBOL_GPL(gpiod_get_optional);
+
+/**
* gpiod_get_index - obtain a GPIO from a multi-index GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
@@ -2778,6 +2816,33 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
EXPORT_SYMBOL_GPL(gpiod_get_index);
/**
+ * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
+ * function
+ * @dev: GPIO consumer, can be NULL for system-global GPIOs
+ * @con_id: function within the GPIO consumer
+ * @index: index of the GPIO to obtain in the consumer
+ *
+ * This is equivalent to gpiod_get_index(), except that when no GPIO with the
+ * specified index was assigned to the requested function it will return NULL.
+ * This is convenient for drivers that need to handle optional GPIOs.
+ */
+struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
+ const char *con_id,
+ unsigned int index)
+{
+ struct gpio_desc *desc;
+
+ desc = gpiod_get_index(dev, con_id, index);
+ if (IS_ERR(desc)) {
+ if (PTR_ERR(desc) == -ENOENT)
+ return NULL;
+ }
+
+ return desc;
+}
+EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
+
+/**
* gpiod_put - dispose of a GPIO descriptor
* @desc: GPIO descriptor to dispose of
*