From 33a2fde5f77bd744b8bd0c694bc173cc968e55a5 Mon Sep 17 00:00:00 2001 From: Tudor Ambarus Date: Thu, 17 Nov 2022 12:52:43 +0200 Subject: [PATCH] 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 Link: https://lore.kernel.org/r/20221117105249.115649-3-tudor.ambarus@microchip.com Signed-off-by: Mark Brown --- drivers/spi/spi.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 4ddd250481f5a..b93a6085d9a0f 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; } -- 2.30.2