spi: Support transfer speed checking in the core

Allow drivers to avoid implementing their own checks for simple rates by
specifying the limits in the master structure.

Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 978dda2c5239..a52f16685d6a 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1387,6 +1387,13 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
                                         BIT(xfer->bits_per_word - 1)))
                                 return -EINVAL;
                 }
+
+                if (xfer->speed_hz && master->min_speed_hz &&
+                    xfer->speed_hz < master->min_speed_hz)
+                        return -EINVAL;
+                if (xfer->speed_hz && master->max_speed_hz &&
+                    xfer->speed_hz > master->max_speed_hz)
+                        return -EINVAL;
         }
 
         message->spi = spi;