spi: Provide per-message prepare and unprepare operations
Many SPI drivers perform setup and tear down on every message, usually
doing things like DMA mapping the message. Provide hooks for them to use
to provide such operations.
This is of limited value for drivers that implement transfer_one_message()
but will be of much greater utility with future factoring out of standard
implementations of that function.
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 8bef0c9..8a30c6b 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -606,6 +606,18 @@
trace_spi_message_start(master->cur_msg);
+ if (master->prepare_message) {
+ ret = master->prepare_message(master, master->cur_msg);
+ if (ret) {
+ dev_err(&master->dev,
+ "failed to prepare message: %d\n", ret);
+ master->cur_msg->status = ret;
+ spi_finalize_current_message(master);
+ return;
+ }
+ master->cur_msg_prepared = true;
+ }
+
ret = master->transfer_one_message(master, master->cur_msg);
if (ret) {
dev_err(&master->dev,
@@ -687,6 +699,7 @@
{
struct spi_message *mesg;
unsigned long flags;
+ int ret;
spin_lock_irqsave(&master->queue_lock, flags);
mesg = master->cur_msg;
@@ -695,6 +708,15 @@
queue_kthread_work(&master->kworker, &master->pump_messages);
spin_unlock_irqrestore(&master->queue_lock, flags);
+ if (master->cur_msg_prepared && master->unprepare_message) {
+ ret = master->unprepare_message(master, mesg);
+ if (ret) {
+ dev_err(&master->dev,
+ "failed to unprepare message: %d\n", ret);
+ }
+ }
+ master->cur_msg_prepared = false;
+
mesg->state = NULL;
if (mesg->complete)
mesg->complete(mesg->context);