spi: make spi-max-frequency optional

We only need a spi-max-frequency when we specifically request a
spi frequency lower than the max speed of spi host.
This property is already documented as optional property and current
host drivers are implemented to operate at highest speed possible
when spi->max_speed_hz is 0.
This patch makes spi-max-frequency an optional property so that
we could just omit it to use max controller speed.

Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Link: https://lore.kernel.org/r/20200306085052.28258-2-gch981213@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 38b4c78df506c060fa49d9b86e97020e7a910b48..c0c55dc799726f3a2924ae4f3a57c956fd4fe7e5 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1955,13 +1955,8 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
                spi->mode |= SPI_CS_HIGH;
 
        /* Device speed */
-       rc = of_property_read_u32(nc, "spi-max-frequency", &value);
-       if (rc) {
-               dev_err(&ctlr->dev,
-                       "%pOF has no valid 'spi-max-frequency' property (%d)\n", nc, rc);
-               return rc;
-       }
-       spi->max_speed_hz = value;
+       if (!of_property_read_u32(nc, "spi-max-frequency", &value))
+               spi->max_speed_hz = value;
 
        return 0;
 }