mfd: Deny ab8500 suspend if i2c transfer is ongoing

If we are in the middle of an I2C transfer we need to deny suspend
of the AB8500 core. Implement an atomic reference counter for the
I2C operations to make sure we don't do this.

Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Reviewed-by: Mattias Wallin <mattias.wallin@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/include/linux/mfd/abx500/ab8500.h b/include/linux/mfd/abx500/ab8500.h
index d798f5b6a55f..91dd3ef63e99 100644
--- a/include/linux/mfd/abx500/ab8500.h
+++ b/include/linux/mfd/abx500/ab8500.h
@@ -7,6 +7,7 @@
 #ifndef MFD_AB8500_H
 #define MFD_AB8500_H
 
+#include <linux/atomic.h>
 #include <linux/mutex.h>
 
 struct device;
@@ -224,6 +225,7 @@ enum ab8500_version {
  * @dev: parent device
  * @lock: read/write operations lock
  * @irq_lock: genirq bus lock
+ * @transfer_ongoing: 0 if no transfer ongoing
  * @irq: irq line
  * @version: chip version id (e.g. ab8500 or ab9540)
  * @chip_id: chip revision id
@@ -242,7 +244,7 @@ struct ab8500 {
         struct device   *dev;
         struct mutex    lock;
         struct mutex    irq_lock;
-
+        atomic_t        transfer_ongoing;
         int             irq_base;
         int             irq;
         enum ab8500_version version;
@@ -288,6 +290,8 @@ extern int __devinit ab8500_init(struct ab8500 *ab8500,
                                  enum ab8500_version version);
 extern int __devexit ab8500_exit(struct ab8500 *ab8500);
 
+extern int ab8500_suspend(struct ab8500 *ab8500);
+
 static inline int is_ab8500(struct ab8500 *ab)
 {
         return ab->version == AB8500_VERSION_AB8500;