spi: sunxi: set maximum and minimum speed of SPI master

The speed limits are unset in the sun4i and sun6i SPI drivers.

The maximum speed of SPI master is used when maximum speed of SPI slave
is not specified. Also the __spi_validate function should check that
transfer speeds do not exceed the master limits.

The user manual for A10 and A31 specifies maximum
speed of the SPI clock as 100MHz and minimum as 3kHz.

Setting the SPI clock to out-of-spec values can lock up the SoC.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
--
v2:
new patch
v3:
fix constant style
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c
index 07ce7c9..d02cf98 100644 (file)
--- a/drivers/spi/spi-sun4i.c
+++ b/drivers/spi/spi-sun4i.c
@@ -392,6 +392,8 @@ static int sun4i_spi_probe(struct platform_device *pdev)
        }
 
        sspi->master = master;
+       master->max_speed_hz = 100 * 1000 * 1000;
+       master->min_speed_hz = 3 * 1000;
        master->set_cs = sun4i_spi_set_cs;
        master->transfer_one = sun4i_spi_transfer_one;
        master->num_chipselect = 4;

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 6fa6ff1..d5a6a2e 100644 (file)
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -390,6 +390,8 @@ static int sun6i_spi_probe(struct platform_device *pdev)
        }
 
        sspi->master = master;
+       master->max_speed_hz = 100 * 1000 * 1000;
+       master->min_speed_hz = 3 * 1000;
        master->set_cs = sun6i_spi_set_cs;
        master->transfer_one = sun6i_spi_transfer_one;
        master->num_chipselect = 4;