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authorJoy Chakraborty <joychakr@google.com>2023-05-12 10:47:44 +0000
committerMark Brown <broonie@kernel.org>2023-05-15 10:46:17 +0900
commit020a3947e7f18e790cc72785281755f8c49e11d4 (patch)
tree820a48a67b87bc4fa8b434b531568f958ee39d8b /drivers/spi
parentd1ca1c5297ba9260942c0b3f1171a98a432bdfec (diff)
spi: dw: Add DMA address widths capability check
Store address width capabilities of DMA controller during init and check the same per transfer to make sure the bits/word requirement can be met. Current DW DMA driver requires both tx and rx channel to be configured and functional hence a subset of both tx and rx channel address width capability is checked with the width requirement(n_bytes) for a transfer. * tested on Baikal-T1 based system with DW SPI-looped back interface transferring a chunk of data with DFS:8,12,16. Signed-off-by: Joy Chakraborty <joychakr@google.com Reviewed-by: Serge Semin <fancer.lancer@gmail.com Tested-by: Serge Semin <fancer.lancer@gmail.com Link: https://lore.kernel.org/r/20230512104746.1797865-3-joychakr@google.com Signed-off-by: Mark Brown <broonie@kernel.org
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-dw-dma.c15
-rw-r--r--drivers/spi/spi-dw.h1
2 files changed, 15 insertions, 1 deletions
diff --git a/drivers/spi/spi-dw-dma.c b/drivers/spi/spi-dw-dma.c
index 2363317a0dca..df819652901a 100644
--- a/drivers/spi/spi-dw-dma.c
+++ b/drivers/spi/spi-dw-dma.c
@@ -98,6 +98,13 @@ static int dw_spi_dma_caps_init(struct dw_spi *dws)
else
dws->dma_sg_burst = 0;
+ /*
+ * Assuming both channels belong to the same DMA controller hence the
+ * peripheral side address width capabilities most likely would be
+ * the same.
+ */
+ dws->dma_addr_widths = tx.dst_addr_widths & rx.src_addr_widths;
+
return 0;
}
@@ -239,8 +246,14 @@ static bool dw_spi_can_dma(struct spi_controller *master,
struct spi_device *spi, struct spi_transfer *xfer)
{
struct dw_spi *dws = spi_controller_get_devdata(master);
+ enum dma_slave_buswidth dma_bus_width;
+
+ if (xfer->len <= dws->fifo_len)
+ return false;
+
+ dma_bus_width = dw_spi_dma_convert_width(dws->n_bytes);
- return xfer->len > dws->fifo_len;
+ return dws->dma_addr_widths & BIT(dma_bus_width);
}
static int dw_spi_dma_wait(struct dw_spi *dws, unsigned int len, u32 speed)
diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
index 9e8eb2b52d5c..3962e6dcf880 100644
--- a/drivers/spi/spi-dw.h
+++ b/drivers/spi/spi-dw.h
@@ -190,6 +190,7 @@ struct dw_spi {
struct dma_chan *rxchan;
u32 rxburst;
u32 dma_sg_burst;
+ u32 dma_addr_widths;
unsigned long dma_chan_busy;
dma_addr_t dma_addr; /* phy address of the Data register */
const struct dw_spi_dma_ops *dma_ops;