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Subject[PATCH v2 1/3] spi: Use a 32-bit DT property for spi-cs-setup-delay-ns
Date
From: Janne Grunau <j@jannau.net>

65us is not a reasonable maximum for this property, as some devices
might need a much longer setup time (e.g. those driven by firmware on
the other end). Plus, device tree property values are in 32-bit cells
and smaller widths should not be used without good reason.

Also move the logic to a helper function, since this will later be used
to parse other CS delay properties too.

Fixes: 33a2fde5f77b ("spi: Introduce spi-cs-setup-ns property")
Signed-off-by: Janne Grunau <j@jannau.net>
Signed-off-by: Hector Martin <marcan@marcan.st>
---
drivers/spi/spi.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 15f174f4e056..3f33934f5429 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2220,11 +2220,26 @@ void spi_flush_queue(struct spi_controller *ctlr)
/*-------------------------------------------------------------------------*/

#if defined(CONFIG_OF)
+static void of_spi_parse_dt_cs_delay(struct device_node *nc,
+ struct spi_delay *delay, const char *prop)
+{
+ u32 value;
+
+ if (!of_property_read_u32(nc, prop, &value)) {
+ if (value > U16_MAX) {
+ delay->value = DIV_ROUND_UP(value, 1000);
+ delay->unit = SPI_DELAY_UNIT_USECS;
+ } else {
+ delay->value = value;
+ delay->unit = SPI_DELAY_UNIT_NSECS;
+ }
+ }
+}
+
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.) */
@@ -2310,10 +2325,8 @@ 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-delay-ns", &cs_setup)) {
- spi->cs_setup.value = cs_setup;
- spi->cs_setup.unit = SPI_DELAY_UNIT_NSECS;
- }
+ /* Device CS delays */
+ of_spi_parse_dt_cs_delay(nc, &spi->cs_setup, "spi-cs-setup-delay-ns");

return 0;
}
--
2.35.1
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