This adds __spi_validate() to validate spi messages. This function is a
stripped down version from the Kernel. The motivation for adding this
was to fill in xfer->bits_per_word from spi->bits_per_word so that a
spi bus driver can use the former.
Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
drivers/spi/spi.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
include/spi/spi.h | 4 ++++
2 files changed, 50 insertions(+)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index bd615b4e99..0694f14c39 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -297,8 +297,54 @@ struct spi_controller *spi_get_controller(int bus)
return NULL;
}
+static int __spi_validate(struct spi_device *spi, struct spi_message *message)
+{
+ struct spi_controller *ctlr = spi->controller;
+ struct spi_transfer *xfer;
+ int w_size;
+
+ if (list_empty(&message->transfers))
+ return -EINVAL;
+
+ list_for_each_entry(xfer, &message->transfers, transfer_list) {
+ if (!xfer->bits_per_word)
+ xfer->bits_per_word = spi->bits_per_word;
+
+ if (!xfer->speed_hz)
+ xfer->speed_hz = spi->max_speed_hz;
+
+ if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
+ xfer->speed_hz = ctlr->max_speed_hz;
+
+ /*
+ * SPI transfer length should be multiple of SPI word size
+ * where SPI word size should be power-of-two multiple
+ */
+ if (xfer->bits_per_word <= 8)
+ w_size = 1;
+ else if (xfer->bits_per_word <= 16)
+ w_size = 2;
+ else
+ w_size = 4;
+
+ /* No partial transfers accepted */
+ if (xfer->len % w_size)
+ return -EINVAL;
+ }
+
+ message->status = -EINPROGRESS;
+
+ return 0;
+}
+
int spi_sync(struct spi_device *spi, struct spi_message *message)
{
+ int status;
+
+ status = __spi_validate(spi, message);
+ if (status != 0)
+ return status;
+
return spi->controller->transfer(spi, message);
}
diff --git a/include/spi/spi.h b/include/spi/spi.h
index 48a90bcca7..66e0500d04 100644
--- a/include/spi/spi.h
+++ b/include/spi/spi.h
@@ -126,6 +126,7 @@ struct spi_message;
* SPI slaves, and are numbered from zero to num_chipselects.
* each slave has a chipselect signal, but it's common that not
* every chipselect is connected to a slave.
+ * @max_speed_hz: Highest supported transfer speed
* @setup: updates the device mode and clocking records used by a
* device's SPI controller; protocol code may call this. This
* must fail if an unrecognized or unsupported mode is requested.
@@ -171,6 +172,9 @@ struct spi_controller {
*/
u16 num_chipselect;
+ /* limits on transfer speed */
+ u32 max_speed_hz;
+
/* setup mode and clock, etc (spi driver may call many times) */
int (*setup)(struct spi_device *spi);
--
2.26.0.rc2
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