2 files changed, 21 insertions, 0 deletions

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 978dda2c5239..361cced68069 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -553,6 +553,10 @@ static void spi_pump_messages(struct kthread_work *work)
                     master->unprepare_transfer_hardware(master))
                         dev_err(&master->dev,
                                 "failed to unprepare transfer hardware\n");
+                if (master->auto_runtime_pm) {
+                        pm_runtime_mark_last_busy(master->dev.parent);
+                        pm_runtime_put_autosuspend(master->dev.parent);
+                }
                 return;
         }
 
@@ -572,11 +576,23 @@ static void spi_pump_messages(struct kthread_work *work)
                 master->busy = true;
         spin_unlock_irqrestore(&master->queue_lock, flags);
 
+        if (!was_busy && master->auto_runtime_pm) {
+                ret = pm_runtime_get_sync(master->dev.parent);
+                if (ret < 0) {
+                        dev_err(&master->dev, "Failed to power device: %d\n",
+                                ret);
+                        return;
+                }
+        }
+
         if (!was_busy && master->prepare_transfer_hardware) {
                 ret = master->prepare_transfer_hardware(master);
                 if (ret) {
                         dev_err(&master->dev,
                                 "failed to prepare transfer hardware\n");
+
+                        if (master->auto_runtime_pm)
+                                pm_runtime_put(master->dev.parent);
                         return;
                 }
         }
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 28e440be1c07..bf0204c00053 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -254,6 +254,9 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  * @busy: message pump is busy
  * @running: message pump is running
  * @rt: whether this queue is set to run as a realtime task
+ * @auto_runtime_pm: the core should ensure a runtime PM reference is held
+ *                   while the hardware is prepared, using the parent
+ *                   device for the spidev
  * @prepare_transfer_hardware: a message will soon arrive from the queue
  *      so the subsystem requests the driver to prepare the transfer hardware
  *      by issuing this call
@@ -374,11 +377,13 @@ struct spi_master {
         bool                            busy;
         bool                            running;
         bool                            rt;
+        bool                            auto_runtime_pm;
 
         int (*prepare_transfer_hardware)(struct spi_master *master);
         int (*transfer_one_message)(struct spi_master *master,
                                     struct spi_message *mesg);
         int (*unprepare_transfer_hardware)(struct spi_master *master);
+
         /* gpio chip select */
         int                     *cs_gpios;
 };