drivers: spi_mcux_flexcomm: fix calls to pm_policy_device_power_lock_put()

Some error cases, and the asynchronous dma case, were not calling
pm_policy_device_power_lock_put() at the right time.

Signed-off-by: Mike J. Chen <[email protected]>

Author: mjchen0

drivers/spi/spi_mcux_flexcomm.c

@@ -147,6 +147,7 @@ static void spi_mcux_transfer_next_packet(const struct device *dev)
 		LOG_ERR("Transfer could not start");
 		spi_context_cs_control(&data->ctx, false);
 		spi_context_complete(&data->ctx, dev, -EIO);
+		pm_policy_device_power_lock_put(dev);
 	}
 }
 
@@ -338,12 +339,14 @@ static void spi_mcux_dma_callback(const struct device *dev, void *arg,
 			data->status_flags |= SPI_MCUX_FLEXCOMM_DMA_RX_DONE_FLAG;
 			spi_context_cs_control(&data->ctx, false);
 			spi_context_complete(&data->ctx, spi_dev, 0);
+			pm_policy_device_power_lock_put(dev);
 		} else {
 			LOG_ERR("DMA callback channel %d is not valid.",
 								channel);
 			data->status_flags |= SPI_MCUX_FLEXCOMM_DMA_ERROR_FLAG;
 			spi_context_cs_control(&data->ctx, false);
 			spi_context_complete(&data->ctx, spi_dev, -EIO);
+			pm_policy_device_power_lock_put(dev);
 		}
 	}
 }
@@ -683,6 +686,10 @@ static int transceive_dma(const struct device *dev,
 		spi_context_update_rx(&data->ctx, data->word_size_bytes, data->transfer_len);
 		spi_context_cs_control(&data->ctx, false);
 		spi_context_complete(&data->ctx, dev, 0);
+		/* If asynchronous was true, set to false since transfer is done and we
+		 * want to release the power lock below.
+		 */
+		asynchronous = false;
 	} else {
 		/* Enable DMATX/RX. */
 		base->FIFOCFG |= SPI_FIFOCFG_DMARX_MASK | SPI_FIFOCFG_DMATX_MASK;
@@ -693,12 +700,21 @@ static int transceive_dma(const struct device *dev,
 		}
 	}
 
+	/* if asynchronous is true, spi_context_wait_for_completion() just returns 0
+	 * and spi_context_release() is a noop
+	 */
 	ret = spi_context_wait_for_completion(&data->ctx);
 
 out:
 	spi_context_release(&data->ctx, ret);
 
-	pm_policy_device_power_lock_put(dev);
+	if (!asynchronous || (ret != 0)) {
+		/* Only release the power lock if synchronous, or if an error occurred.
+		 * For asynchronous case, the power_lock is released in
+		 * when the transfer is done in the dma completion callback
+		 */
+		pm_policy_device_power_lock_put(dev);
+	}
 
 	return ret;
 }