Merge branch 'next' (accumulated 3.16 merge window patches) into master

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

2 files changed, 45 insertions, 1 deletions

diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index bed128e8f4b..05e53ccb708 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -1,6 +1,7 @@
 #ifndef __LINUX_GPIO_CONSUMER_H
 #define __LINUX_GPIO_CONSUMER_H
 
+#include <linux/bug.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
 
@@ -23,6 +24,12 @@ struct gpio_desc *__must_check gpiod_get(struct device *dev,
 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
 					       const char *con_id,
 					       unsigned int idx);
+struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
+						  const char *con_id);
+struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
+							const char *con_id,
+							unsigned int index);
+
 void gpiod_put(struct gpio_desc *desc);
 
 struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
@@ -30,6 +37,12 @@ struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
 struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
 						    const char *con_id,
 						    unsigned int idx);
+struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
+						       const char *con_id);
+struct gpio_desc *__must_check
+devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
+			      unsigned int index);
+
 void devm_gpiod_put(struct device *dev, struct gpio_desc *desc);
 
 int gpiod_get_direction(const struct gpio_desc *desc);
@@ -73,6 +86,20 @@ static inline struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
 {
 	return ERR_PTR(-ENOSYS);
 }
+
+static inline struct gpio_desc *__must_check
+gpiod_get_optional(struct device *dev, const char *con_id)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline struct gpio_desc *__must_check
+gpiod_get_index_optional(struct device *dev, const char *con_id,
+			 unsigned int index)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
 static inline void gpiod_put(struct gpio_desc *desc)
 {
 	might_sleep();
@@ -93,6 +120,20 @@ struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
 {
 	return ERR_PTR(-ENOSYS);
 }
+
+static inline struct gpio_desc *__must_check
+devm_gpiod_get_optional(struct device *dev, const char *con_id)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline struct gpio_desc *__must_check
+devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
+			      unsigned int index)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
 static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
 {
 	might_sleep();
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 1827b43966d..573e4f3243d 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -51,7 +51,10 @@ struct seq_file;
  *      format specifier for an unsigned int.  It is substituted by the actual
  *      number of the gpio.
  * @can_sleep: flag must be set iff get()/set() methods sleep, as they
- *	must while accessing GPIO expander chips over I2C or SPI
+ *	must while accessing GPIO expander chips over I2C or SPI. This
+ *	implies that if the chip supports IRQs, these IRQs need to be threaded
+ *	as the chip access may sleep when e.g. reading out the IRQ status
+ *	registers.
  * @exported: flags if the gpiochip is exported for use from sysfs. Private.
  *
  * A gpio_chip can help platforms abstract various sources of GPIOs so