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authorVladimir Oltean <vladimir.oltean@nxp.com>2020-03-18 02:16:01 +0200
committerMark Brown <broonie@kernel.org>2020-03-18 22:45:01 +0000
commit138f56ef914b30087c560492e5997f17d494d043 (patch)
tree6de060b63092cbf4720e72c760cb0ca221465a16 /drivers/spi
parent5b342c5ab7cde6c543faf46e30bb501feaa2e435 (diff)
downloadlinux-138f56ef914b30087c560492e5997f17d494d043.tar.bz2
spi: spi-fsl-dspi: Add support for LS1028A
This is similar to the DSPI instantiation on LS1028A, except that: - The A-011218 erratum has been fixed, so DMA works - The endianness is different, which has implications on XSPI mode Some benchmarking with the following command: spidev_test --device /dev/spidev2.0 --bpw 8 --size 256 --cpha --iter 10000000 --speed 20000000 shows that in DMA mode, it can achieve around 2400 kbps, and in XSPI mode, the same command goes up to 4700 kbps. This is somewhat to be expected, since the DMA buffer size is extremely small at 8 bytes, the winner becomes whomever can prepare the buffers for transmission quicker, and DMA mode has higher overhead there. So XSPI FIFO mode has been chosen as the operating mode for this chip. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20200318001603.9650-11-olteanv@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-fsl-dspi.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 5873752a091e..50e41f66a2d7 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -124,6 +124,7 @@ struct fsl_dspi_devtype_data {
enum {
LS1021A,
LS1012A,
+ LS1028A,
LS1043A,
LS1046A,
LS2080A,
@@ -151,6 +152,11 @@ static const struct fsl_dspi_devtype_data devtype_data[] = {
.max_clock_factor = 8,
.fifo_size = 16,
},
+ [LS1028A] = {
+ .trans_mode = DSPI_XSPI_MODE,
+ .max_clock_factor = 8,
+ .fifo_size = 4,
+ },
[LS1043A] = {
/* Has A-011218 DMA erratum */
.trans_mode = DSPI_XSPI_MODE,
@@ -1051,6 +1057,9 @@ static const struct of_device_id fsl_dspi_dt_ids[] = {
.compatible = "fsl,ls1012a-dspi",
.data = &devtype_data[LS1012A],
}, {
+ .compatible = "fsl,ls1028a-dspi",
+ .data = &devtype_data[LS1028A],
+ }, {
.compatible = "fsl,ls1043a-dspi",
.data = &devtype_data[LS1043A],
}, {