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authorTudor Ambarus <tudor.ambarus@microchip.com>2022-11-17 13:52:43 +0300
committerMark Brown <broonie@kernel.org>2022-11-18 14:57:09 +0300
commit33a2fde5f77bd744b8bd0c694bc173cc968e55a5 (patch)
tree67cc49125abe8eac4af3bd85488405989ed90a4b /drivers/spi
parentf6c911f3308c1cfb97ae1da6654080d7104e2df2 (diff)
downloadlinux-33a2fde5f77bd744b8bd0c694bc173cc968e55a5.tar.xz
spi: Introduce spi-cs-setup-ns property
SPI NOR flashes have specific cs-setup time requirements without which they can't work at frequencies close to their maximum supported frequency, as they miss the first bits of the instruction command. Unrecognized commands are ignored, thus the flash will be unresponsive. Introduce the spi-cs-setup-ns property to allow spi devices to specify their cs setup time. Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Link: https://lore.kernel.org/r/20221117105249.115649-3-tudor.ambarus@microchip.com Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 4ddd250481f5..b93a6085d9a0 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2224,6 +2224,7 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
struct device_node *nc)
{
u32 value;
+ u16 cs_setup;
int rc;
/* Mode (clock phase/polarity/etc.) */
@@ -2309,6 +2310,11 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
if (!of_property_read_u32(nc, "spi-max-frequency", &value))
spi->max_speed_hz = value;
+ if (!of_property_read_u16(nc, "spi-cs-setup-ns", &cs_setup)) {
+ spi->cs_setup.value = cs_setup;
+ spi->cs_setup.unit = SPI_DELAY_UNIT_NSECS;
+ }
+
return 0;
}