[3/5] spi: Use a 32-bit DT property for spi-cs-setup-delay-ns
Commit Message
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 | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)
Comments
On Wed, Jan 04, 2023 at 06:36:29PM +0900, Janne Grunau wrote:
> 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.
This breaks allmodconfig builds (I tested x86 but this should happen
for anything with -Werror):
/build/stage/linux/drivers/spi/spi.c: In function ‘of_spi_parse_dt’:
/build/stage/linux/drivers/spi/spi.c:2243:13: error: unused variable ‘cs_setup’ [-Werror=unused-variable]
2243 | u16 cs_setup;
| ^~~~~~~~
cc1: all warnings being treated as errors
On 07/01/2023 01.26, Mark Brown wrote:
> On Wed, Jan 04, 2023 at 06:36:29PM +0900, Janne Grunau wrote:
>
>> 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.
>
> This breaks allmodconfig builds (I tested x86 but this should happen
> for anything with -Werror):
>
> /build/stage/linux/drivers/spi/spi.c: In function ‘of_spi_parse_dt’:
> /build/stage/linux/drivers/spi/spi.c:2243:13: error: unused variable ‘cs_setup’ [-Werror=unused-variable]
> 2243 | u16 cs_setup;
> | ^~~~~~~~
> cc1: all warnings being treated as errors
Yeah, the kernel test robot caught this one too. Sorry for missing it
(it got buried in warning noise in a rather large rebuild on my side).
That line should've been removed in #3 :(
I see two patches got applied already. Do you want me to just respin #3-#5?
- Hector
On Sat, Jan 07, 2023 at 01:40:49AM +0900, Hector Martin wrote:
> Yeah, the kernel test robot caught this one too. Sorry for missing it
> (it got buried in warning noise in a rather large rebuild on my side).
> That line should've been removed in #3 :(
> I see two patches got applied already. Do you want me to just respin #3-#5?
Yes, please.
@@ -2220,6 +2220,22 @@ 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)
{
@@ -2310,10 +2326,8 @@ 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;
}