iio: accel: mma9553: document use of mutex

Fix checkpatch.pl --strict check:
CHECK: struct mutex definition without comment
+     struct mutex mutex;

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/accel/mma9553.c b/drivers/iio/accel/mma9553.c
index 08f28c3eb6cc1fd7860461dadc4ee1ce81e80c92..a605280637e933ccacd0d07917b8054904634bba 100644 (file)
--- a/drivers/iio/accel/mma9553.c
+++ b/drivers/iio/accel/mma9553.c
@@ -182,6 +182,10 @@ struct mma9553_conf_regs {
 
 struct mma9553_data {
        struct i2c_client *client;
+       /*
+        * 1. Serialize access to HW (requested by mma9551_core API).
+        * 2. Serialize sequences that power on/off the device and access HW.
+        */
        struct mutex mutex;
        struct mma9553_conf_regs conf;
        struct mma9553_event events[MMA9553_EVENTS_INFO_SIZE];