spi: spi-uclass: Fix spi_claim_bus() speed/mode setup logic

Currently, when different spi slaves claim the bus consecutively using
spi_claim_bus(), spi_set_speed_mode() will only be executed on the first
two calls, leaving the bus in a bad state starting with the third call.

This patch drops spi_slave->speed member and adds caching of bus
speed/mode in dm_spi_bus struct. It also updates spi_claim_bus() to call
spi_set_speed_mode() if either speed or mode is different from what the
bus is currently configured for. Current behavior is to only take into
account the speed, but not the mode, which seems wrong.

Fixes: 60e2809a848 ("dm: spi: Avoid setting the speed with every transfer")
Reviewed-by: Simon Glass <sjg@chromium.org>
Reported-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reported-by: Moshe, Yaniv <yanivmo@amazon.com>
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>

1 files changed, 14 insertions, 4 deletions

diff --git a/include/spi.h b/include/spi.h
index a0342e31695..e81f7996500 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -39,9 +39,22 @@
 
 #define SPI_DEFAULT_WORDLEN	8
 
-/* TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave */
+/**
+ * struct dm_spi_bus - SPI bus info
+ *
+ * This contains information about a SPI bus. To obtain this structure, use
+ * dev_get_uclass_priv(bus) where bus is the SPI bus udevice.
+ *
+ * @max_hz:	Maximum speed that the bus can tolerate.
+ * @speed:	Current bus speed. This is 0 until the bus is first claimed.
+ * @mode:	Current bus mode. This is 0 until the bus is first claimed.
+ *
+ * TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave.
+ */
 struct dm_spi_bus {
 	uint max_hz;
+	uint speed;
+	uint mode;
 };
 
 /**
@@ -112,8 +125,6 @@ enum spi_polarity {
  *
  * @dev:		SPI slave device
  * @max_hz:		Maximum speed for this slave
- * @speed:		Current bus speed. This is 0 until the bus is first
- *			claimed.
  * @bus:		ID of the bus that the slave is attached to. For
  *			driver model this is the sequence number of the SPI
  *			bus (dev_seq(bus)) so does not need to be stored
@@ -131,7 +142,6 @@ struct spi_slave {
 #if CONFIG_IS_ENABLED(DM_SPI)
 	struct udevice *dev;	/* struct spi_slave is dev->parentdata */
 	uint max_hz;
-	uint speed;
 #else
 	unsigned int bus;
 	unsigned int cs;