@@ -4189,6 +4189,16 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
if (_spi_xfer_word_delay_update(xfer, spi))
return -EINVAL;
+
+ /* make sure controller supports required offload features */
+ if (xfer->offload_flags) {
+ if (!message->offload)
+ return -EINVAL;
+
+ if ((xfer->offload_flags & ctlr->offload_xfer_flags)
+ != xfer->offload_flags)
+ return -EINVAL;
+ }
}
message->status = -EINPROGRESS;
@@ -501,6 +501,8 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch
* This field is optional and should only be implemented if the
* controller has native support for memory like operations.
* @mem_caps: controller capabilities for the handling of memory operations.
+ * @offload_xfer_flags: flags supported by this controller for offloading
+ * transfers. See struct spi_transfer for the list of flags.
* @offload_ops: operations for controllers with offload support.
* @unprepare_message: undo any work done by prepare_message().
* @slave_abort: abort the ongoing transfer request on an SPI slave controller
@@ -751,6 +753,7 @@ struct spi_controller {
const struct spi_controller_mem_caps *mem_caps;
/* Operations for controllers with offload support. */
+ unsigned int offload_xfer_flags;
const struct spi_controller_offload_ops *offload_ops;
/* GPIO chip select */
@@ -991,6 +994,7 @@ struct spi_res {
* @transfer_list: transfers are sequenced through @spi_message.transfers
* @tx_sg: Scatterlist for transmit, currently not for client use
* @rx_sg: Scatterlist for receive, currently not for client use
+ * @offload_flags: flags for xfers that use special hardware offload features
* @ptp_sts_word_pre: The word (subject to bits_per_word semantics) offset
* within @tx_buf for which the SPI device is requesting that the time
* snapshot for this transfer begins. Upon completing the SPI transfer,
@@ -1107,6 +1111,12 @@ struct spi_transfer {
u32 effective_speed_hz;
+ unsigned int offload_flags;
+/* this is write xfer but TX uses external data stream rather than tx_buf */
+#define SPI_OFFLOAD_XFER_TX_STREAM BIT(0)
+/* this is read xfer but RX uses external data stream rather than rx_buf */
+#define SPI_OFFLOAD_XFER_RX_STREAM BIT(1)
+
unsigned int ptp_sts_word_pre;
unsigned int ptp_sts_word_post;
Most configuration of SPI offloads is handles opaquely using the ID handle that is passed to the various offload functions. However, there are some offload features that need to be controller on a per transfer basis. This patch adds a flags field to the spi_transfer structure to allow specifying such features. The first feature to be added is the ability to stream data to/from a hardware sink/source rather than using a tx or rx buffer. Additional flags can be added in the future as needed. A flags field is also added to the controller struct for controllers to indicate which flags are supported. This allows for generic checking of offload capabilities during __spi_validate() so that each controller doesn't have to provide their own validation. Signed-off-by: David Lechner <dlechner@baylibre.com> --- v2 changes: This is also split out from "spi: add core support for controllers with offload capabilities". In the previous version, we were using (void *)-1 as a sentinel value that could be assigned, e.g. to rx_buf. But this was naive since there is core code that would try to dereference this pointer. So instead, we've added a new flags field to the spi_transfer structure for this sort of thing. This also has the advantage of being able to be used in the future for other arbitrary features. --- drivers/spi/spi.c | 10 ++++++++++ include/linux/spi/spi.h | 10 ++++++++++ 2 files changed, 20 insertions(+)