diff options
| author | Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com> | 2018-10-30 21:09:48 +0100 |
|---|---|---|
| committer | Simon Glass <sjg@chromium.org> | 2018-11-20 19:14:22 -0700 |
| commit | 12bfb2e05fc29bfbec7eb76ea8cc02e130268801 (patch) | |
| tree | 05dd2716fc3975376ba204b216211318369584cc /drivers/spi | |
| parent | b23644858bec1a21743debccb6643af7df5c48b4 (diff) | |
dm: spi: prevent setting a speed of 0 Hz
When the device tree is missing a correct spi slave description below
the bus (compatible "spi-flash" or spi-max-frequency are missing),
the 'set_speed' callback can be called with 'speed' == 0 Hz.
At least with cadence qspi, this leads to a division by zero.
Prevent this by initializing speed to 100 kHz in this case (same
fallback value as is done in 'dm_spi_claim_bus') and issue a warning
to console.
Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-uclass.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c index b84255bd27..2bc289a74c 100644 --- a/drivers/spi/spi-uclass.c +++ b/drivers/spi/spi-uclass.c @@ -15,6 +15,8 @@ DECLARE_GLOBAL_DATA_PTR; +#define SPI_DEFAULT_SPEED_HZ 100000 + static int spi_set_speed_mode(struct udevice *bus, int speed, int mode) { struct dm_spi_ops *ops; @@ -58,7 +60,7 @@ int dm_spi_claim_bus(struct udevice *dev) speed = spi->max_hz; } if (!speed) - speed = 100000; + speed = SPI_DEFAULT_SPEED_HZ; if (speed != slave->speed) { int ret = spi_set_speed_mode(bus, speed, slave->mode); @@ -300,7 +302,13 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode, } plat = dev_get_parent_platdata(dev); plat->cs = cs; - plat->max_hz = speed; + if (speed) { + plat->max_hz = speed; + } else { + printf("Warning: SPI speed fallback to %u kHz\n", + SPI_DEFAULT_SPEED_HZ / 1000); + plat->max_hz = SPI_DEFAULT_SPEED_HZ; + } plat->mode = mode; created = true; } else if (ret) { @@ -374,7 +382,8 @@ int spi_slave_ofdata_to_platdata(struct udevice *dev, int value; plat->cs = dev_read_u32_default(dev, "reg", -1); - plat->max_hz = dev_read_u32_default(dev, "spi-max-frequency", 0); + plat->max_hz = dev_read_u32_default(dev, "spi-max-frequency", + SPI_DEFAULT_SPEED_HZ); if (dev_read_bool(dev, "spi-cpol")) mode |= SPI_CPOL; if (dev_read_bool(dev, "spi-cpha")) |