2 files changed, 76 insertions, 27 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index aa6a11b452e2..8fbc67a88465 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1458,26 +1458,14 @@ EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
  * on each other, and help provide better diagnostics in debugfs.
  * They're called even less than the "set direction" calls.
  */
-static int gpiod_request(struct gpio_desc *desc, const char *label)
+static int __gpiod_request(struct gpio_desc *desc, const char *label)
 {
-        struct gpio_chip        *chip;
-        int                     status = -EPROBE_DEFER;
+        struct gpio_chip        *chip = desc->chip;
+        int                     status;
         unsigned long           flags;
 
-        if (!desc) {
-                pr_warn("%s: invalid GPIO\n", __func__);
-                return -EINVAL;
-        }
-
         spin_lock_irqsave(&gpio_lock, flags);
 
-        chip = desc->chip;
-        if (chip == NULL)
-                goto done;
-
-        if (!try_module_get(chip->owner))
-                goto done;
-
         /* NOTE:  gpio_request() can be called in early boot,
          * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
          */
@@ -1487,7 +1475,6 @@ static int gpiod_request(struct gpio_desc *desc, const char *label)
                 status = 0;
         } else {
                 status = -EBUSY;
-                module_put(chip->owner);
                 goto done;
         }
 
@@ -1499,7 +1486,6 @@ static int gpiod_request(struct gpio_desc *desc, const char *label)
 
                 if (status < 0) {
                         desc_set_label(desc, NULL);
-                        module_put(chip->owner);
                         clear_bit(FLAG_REQUESTED, &desc->flags);
                         goto done;
                 }
@@ -1511,9 +1497,34 @@ static int gpiod_request(struct gpio_desc *desc, const char *label)
                 spin_lock_irqsave(&gpio_lock, flags);
         }
 done:
+        spin_unlock_irqrestore(&gpio_lock, flags);
+        return status;
+}
+
+static int gpiod_request(struct gpio_desc *desc, const char *label)
+{
+        int status = -EPROBE_DEFER;
+        struct gpio_chip *chip;
+
+        if (!desc) {
+                pr_warn("%s: invalid GPIO\n", __func__);
+                return -EINVAL;
+        }
+
+        chip = desc->chip;
+        if (!chip)
+                goto done;
+
+        if (try_module_get(chip->owner)) {
+                status = __gpiod_request(desc, label);
+                if (status < 0)
+                        module_put(chip->owner);
+        }
+
+done:
         if (status)
                 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
-        spin_unlock_irqrestore(&gpio_lock, flags);
+
         return status;
 }
 
@@ -1523,18 +1534,14 @@ int gpio_request(unsigned gpio, const char *label)
 }
 EXPORT_SYMBOL_GPL(gpio_request);
 
-static void gpiod_free(struct gpio_desc *desc)
+static bool __gpiod_free(struct gpio_desc *desc)
 {
+        bool                    ret = false;
         unsigned long           flags;
         struct gpio_chip        *chip;
 
         might_sleep();
 
-        if (!desc) {
-                WARN_ON(extra_checks);
-                return;
-        }
-
         gpiod_unexport(desc);
 
         spin_lock_irqsave(&gpio_lock, flags);
@@ -1548,15 +1555,23 @@ static void gpiod_free(struct gpio_desc *desc)
                         spin_lock_irqsave(&gpio_lock, flags);
                 }
                 desc_set_label(desc, NULL);
-                module_put(desc->chip->owner);
                 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
                 clear_bit(FLAG_REQUESTED, &desc->flags);
                 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
                 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
-        } else
-                WARN_ON(extra_checks);
+                ret = true;
+        }
 
         spin_unlock_irqrestore(&gpio_lock, flags);
+        return ret;
+}
+
+static void gpiod_free(struct gpio_desc *desc)
+{
+        if (desc && __gpiod_free(desc))
+                module_put(desc->chip->owner);
+        else
+                WARN_ON(extra_checks);
 }
 
 void gpio_free(unsigned gpio)
@@ -1678,6 +1693,37 @@ const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
 }
 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
 
+/**
+ * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
+ * @desc: GPIO descriptor to request
+ * @label: label for the GPIO
+ *
+ * Function allows GPIO chip drivers to request and use their own GPIO
+ * descriptors via gpiolib API. Difference to gpiod_request() is that this
+ * function will not increase reference count of the GPIO chip module. This
+ * allows the GPIO chip module to be unloaded as needed (we assume that the
+ * GPIO chip driver handles freeing the GPIOs it has requested).
+ */
+int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label)
+{
+        if (!desc || !desc->chip)
+                return -EINVAL;
+
+        return __gpiod_request(desc, label);
+}
+
+/**
+ * gpiochip_free_own_desc - Free GPIO requested by the chip driver
+ * @desc: GPIO descriptor to free
+ *
+ * Function frees the given GPIO requested previously with
+ * gpiochip_request_own_desc().
+ */
+void gpiochip_free_own_desc(struct gpio_desc *desc)
+{
+        if (desc)
+                __gpiod_free(desc);
+}
 
 /* Drivers MUST set GPIO direction before making get/set calls.  In
  * some cases this is done in early boot, before IRQs are enabled.
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 82be586c1f90..cf092941a9fd 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -43,4 +43,7 @@ acpi_get_gpiod_by_index(struct device *dev, int index,
 }
 #endif
 
+int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label);
+void gpiochip_free_own_desc(struct gpio_desc *desc);
+
 #endif /* GPIOLIB_H */