Hello.
On 13-03-2011 17:34, Michael Williamson wrote:
The current davinci SPI driver, in DMA mode, is limited to 65535
words for a single transfer. Modify the driver by configuring a
3 dimensional EDMA transfer to support up to 65535x65535
words.
Signed-off-by: Michael Williamson<[email protected]>
[...]
diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
index 037ba82..411cc32 100644
--- a/drivers/spi/davinci_spi.c
+++ b/drivers/spi/davinci_spi.c
[...]
@@ -599,14 +600,30 @@ static int davinci_spi_bufs(struct spi_device *spi,
struct spi_transfer *t)
}
}
+ /*
+ * If number of words is greater than 65535, then we need
+ * to configure a 3 dimension transfer. Use the BCNTRLD
+ * feature to allow for transfers that aren't even multiples
+ * of 65535 (or any other possible b size) by first transferring
+ * the remainder amount then grabbing the next N blocks of
+ * 65535 words.
+ */
+
+ c = dspi->wcount/(SZ_64K-1); /* N 65535 count Blocks */
+ b = dspi->wcount-c*(SZ_64K-1); /* Remainder */
The driver style (and general Linux kernel style) assumes spaces around
operators.
WRB, Sergei
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