Merge branch 'gpio-irq-validmask' into devel

3 files changed, 75 insertions, 3 deletions

diff --git a/Documentation/gpio/driver.txt b/Documentation/gpio/driver.txt
index 6cb35a78eff4..368d5a294d89 100644
--- a/Documentation/gpio/driver.txt
+++ b/Documentation/gpio/driver.txt
@@ -262,6 +262,12 @@ symbol:
   to the container using container_of().
   (See Documentation/driver-model/design-patterns.txt)
 
+  If there is a need to exclude certain GPIOs from the IRQ domain, one can
+  set .irq_need_valid_mask of the gpiochip before gpiochip_add_data() is
+  called. This allocates .irq_valid_mask with as many bits set as there are
+  GPIOs in the chip. Drivers can exclude GPIOs by clearing bits from this
+  mask. The mask must be filled in before gpiochip_irqchip_add() is called.
+
 * gpiochip_set_chained_irqchip(): sets up a chained irq handler for a
   gpio_chip from a parent IRQ and passes the struct gpio_chip* as handler
   data. (Notice handler data, since the irqchip data is likely used by the
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 53ff25ac66d8..23be4daefeed 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -71,6 +71,8 @@ LIST_HEAD(gpio_devices);
 
 static void gpiochip_free_hogs(struct gpio_chip *chip);
 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
+static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
+static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
 
 static bool gpiolib_initialized;
 
@@ -1167,6 +1169,10 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
 	if (status)
 		goto err_remove_from_list;
 
+	status = gpiochip_irqchip_init_valid_mask(chip);
+	if (status)
+		goto err_remove_from_list;
+
 	status = of_gpiochip_add(chip);
 	if (status)
 		goto err_remove_chip;
@@ -1192,6 +1198,7 @@ err_remove_chip:
 	acpi_gpiochip_remove(chip);
 	gpiochip_free_hogs(chip);
 	of_gpiochip_remove(chip);
+	gpiochip_irqchip_free_valid_mask(chip);
 err_remove_from_list:
 	spin_lock_irqsave(&gpio_lock, flags);
 	list_del(&gdev->list);
@@ -1401,6 +1408,40 @@ static struct gpio_chip *find_chip_by_name(const char *name)
  * The following is irqchip helper code for gpiochips.
  */
 
+static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
+{
+	int i;
+
+	if (!gpiochip->irq_need_valid_mask)
+		return 0;
+
+	gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio),
+					   sizeof(long), GFP_KERNEL);
+	if (!gpiochip->irq_valid_mask)
+		return -ENOMEM;
+
+	/* Assume by default all GPIOs are valid */
+	for (i = 0; i < gpiochip->ngpio; i++)
+		set_bit(i, gpiochip->irq_valid_mask);
+
+	return 0;
+}
+
+static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
+{
+	kfree(gpiochip->irq_valid_mask);
+	gpiochip->irq_valid_mask = NULL;
+}
+
+static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
+				       unsigned int offset)
+{
+	/* No mask means all valid */
+	if (likely(!gpiochip->irq_valid_mask))
+		return true;
+	return test_bit(offset, gpiochip->irq_valid_mask);
+}
+
 /**
  * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
  * @gpiochip: the gpiochip to set the irqchip chain to
@@ -1442,9 +1483,12 @@ void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
 	}
 
 	/* Set the parent IRQ for all affected IRQs */
-	for (offset = 0; offset < gpiochip->ngpio; offset++)
+	for (offset = 0; offset < gpiochip->ngpio; offset++) {
+		if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
+			continue;
 		irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
 			       parent_irq);
+	}
 }
 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
 
@@ -1551,9 +1595,12 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
 
 	/* Remove all IRQ mappings and delete the domain */
 	if (gpiochip->irqdomain) {
-		for (offset = 0; offset < gpiochip->ngpio; offset++)
+		for (offset = 0; offset < gpiochip->ngpio; offset++) {
+			if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
+				continue;
 			irq_dispose_mapping(
 				irq_find_mapping(gpiochip->irqdomain, offset));
+		}
 		irq_domain_remove(gpiochip->irqdomain);
 	}
 
@@ -1562,6 +1609,8 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
 		gpiochip->irqchip->irq_release_resources = NULL;
 		gpiochip->irqchip = NULL;
 	}
+
+	gpiochip_irqchip_free_valid_mask(gpiochip);
 }
 
 /**
@@ -1597,6 +1646,7 @@ int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
 			  struct lock_class_key *lock_key)
 {
 	struct device_node *of_node;
+	bool irq_base_set = false;
 	unsigned int offset;
 	unsigned irq_base = 0;
 
@@ -1646,13 +1696,17 @@ int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
 	 * necessary to allocate descriptors for all IRQs.
 	 */
 	for (offset = 0; offset < gpiochip->ngpio; offset++) {
+		if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
+			continue;
 		irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
-		if (offset == 0)
+		if (!irq_base_set) {
 			/*
 			 * Store the base into the gpiochip to be used when
 			 * unmapping the irqs.
 			 */
 			gpiochip->irq_base = irq_base;
+			irq_base_set = true;
+		}
 	}
 
 	acpi_gpiochip_request_interrupts(gpiochip);
@@ -1664,6 +1718,12 @@ EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
 #else /* CONFIG_GPIOLIB_IRQCHIP */
 
 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
+static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
+{
+	return 0;
+}
+static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
+{ }
 
 #endif /* CONFIG_GPIOLIB_IRQCHIP */
 
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 50882e09289b..420b837f2aa7 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -112,6 +112,10 @@ enum single_ended_mode {
  *	initialization, provided by GPIO driver
  * @irq_parent: GPIO IRQ chip parent/bank linux irq number,
  *	provided by GPIO driver
+ * @irq_need_valid_mask: If set core allocates @irq_valid_mask with all
+ *	bits set to one
+ * @irq_valid_mask: If not %NULL holds bitmask of GPIOs which are valid to
+ *	be included in IRQ domain of the chip
  * @lock_key: per GPIO IRQ chip lockdep class
  *
  * A gpio_chip can help platforms abstract various sources of GPIOs so
@@ -190,6 +194,8 @@ struct gpio_chip {
 	irq_flow_handler_t	irq_handler;
 	unsigned int		irq_default_type;
 	int			irq_parent;
+	bool			irq_need_valid_mask;
+	unsigned long		*irq_valid_mask;
 	struct lock_class_key	*lock_key;
 #endif