On 7/25/2023 11:32 PM, Douglas Anderson wrote:
In the patch ("spi: spi-qcom-qspi: Fallback to PIO for xfers that
aren't multiples of 4 bytes") we detect reads that we can't handle
properly and fallback to PIO mode. While that's correct behavior, we
can do better by adding "spi_controller_mem_ops" for our
controller. Once we do this then the caller will give us a transfer
that's a multiple of 4-bytes so we can DMA.
Fixes: b5762d95607e ("spi: spi-qcom-qspi: Add DMA mode support")
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
I checked with a couple of folks here and seemingly the POR for QSPI
controller is for storage device only, so in all likelihood we should be
having a spi-flash at the other end.
For other devices there is QUP anyway.
Hence personally I am happy with this change.
Thank you...
Reviewed-by: Vijaya Krishna Nivarthi <quic_vnivarth@xxxxxxxxxxx>
---
drivers/spi/spi-qcom-qspi.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
index 39b4d8a8107a..b2bbcfd93637 100644
--- a/drivers/spi/spi-qcom-qspi.c
+++ b/drivers/spi/spi-qcom-qspi.c
@@ -659,6 +659,30 @@ static irqreturn_t qcom_qspi_irq(int irq, void *dev_id)
return ret;
}
+static int qcom_qspi_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
+{
+ /*
+ * If qcom_qspi_can_dma() is going to return false we don't need to
+ * adjust anything.
+ */
+ if (op->data.nbytes <= QSPI_MAX_BYTES_FIFO)
+ return 0;
+
+ /*
+ * When reading, the transfer needs to be a multiple of 4 bytes so
+ * shrink the transfer if that's not true. The caller will then do a
+ * second transfer to finish things up.
+ */
+ if (op->data.dir == SPI_MEM_DATA_IN && (op->data.nbytes & 0x3))
+ op->data.nbytes &= ~0x3;
+
+ return 0;
+}
+
+static const struct spi_controller_mem_ops qcom_qspi_mem_ops = {
+ .adjust_op_size = qcom_qspi_adjust_op_size,
+};
+
static int qcom_qspi_probe(struct platform_device *pdev)
{
int ret;
@@ -743,6 +767,7 @@ static int qcom_qspi_probe(struct platform_device *pdev)
if (of_property_read_bool(pdev->dev.of_node, "iommus"))
master->can_dma = qcom_qspi_can_dma;
master->auto_runtime_pm = true;
+ master->mem_ops = &qcom_qspi_mem_ops;
ret = devm_pm_opp_set_clkname(&pdev->dev, "core");
if (ret)
