Merge branch 'gpio-irq-validmask' of /home/linus/linux-pinctrl 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 043128d3e831..19a665f8d455 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);
@@ -1397,6 +1404,40 @@ 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
@@ -1438,9 +1479,12 @@ 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);
 
@@ -1547,9 +1591,12 @@ 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);
         }
 
@@ -1558,6 +1605,8 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
                 gpiochip->irqchip->irq_release_resources = NULL;
                 gpiochip->irqchip = NULL;
         }
+
+        gpiochip_irqchip_free_valid_mask(gpiochip);
 }
 
 /**
@@ -1593,6 +1642,7 @@ 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;
 
@@ -1656,13 +1706,17 @@ 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);
@@ -1674,6 +1728,12 @@ 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 216e6f275aa8..1f0be7213e6d 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