[PATCH 08/12] spi: allow reporting the effectivly used speed_hz for a transfer

[Marco Felsch <m.felsch@pengutronix.de>]

This is a copy of Linux commit:

8<-------------------------------------------------------------------------
commit 5d7e2b5ed5858fe739d4cb8ad22dcce7bd9dbe7b
Author: Martin Sperl <kernel@martin.sperl.org>
Date:   Sat Feb 23 08:49:49 2019 +0000

    spi: core: allow reporting the effectivly used speed_hz for a transfer

    Provide a means for the spi bus driver to report the effectively used
    spi clock frequency used for each spi_transfer.

    Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
    Signed-off-by: Mark Brown <broonie@kernel.org>
8<-------------------------------------------------------------------------

to sync the spi core more with Linux which is required for the later
core common message handling.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 drivers/spi/spi.c | 1 +
 include/spi/spi.h | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index e8a0b1b84be5..78569301776f 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -415,6 +415,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
 	message->spi = spi;
 
 	list_for_each_entry(xfer, &message->transfers, transfer_list) {
+		xfer->effective_speed_hz = 0;
 		if (!xfer->bits_per_word)
 			xfer->bits_per_word = spi->bits_per_word;
 
diff --git a/include/spi/spi.h b/include/spi/spi.h
index 8363e73c6754..2b441e934d12 100644
--- a/include/spi/spi.h
+++ b/include/spi/spi.h
@@ -330,6 +330,9 @@ static inline size_t spi_max_transfer_size(struct spi_device *spi)
  * @len: size of rx and tx buffers (in bytes)
  * @speed_hz: Select a speed other then the device default for this
  *      transfer. If 0 the default (from @spi_device) is used.
+ * @effective_speed_hz: the effective SCK-speed that was used to
+ *      transfer this transfer. Set to 0 if the SPI bus driver does
+ *      not support it.
  * @bits_per_word: select a bits_per_word other then the device default
  *      for this transfer. If 0 the default (from @spi_device) is used.
  * @cs_change: affects chipselect after this transfer completes
@@ -399,6 +402,8 @@ struct spi_transfer {
 	u16		delay_usecs;
 	u32		speed_hz;
 
+	u32		effective_speed_hz;
+
 	struct list_head transfer_list;
 };
 
-- 
2.39.5