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spi/rockchip: Avoid accidentally turning off the clock 

If our client is requesting a clock that is above the maximum clock
then the following division will result in 0:
  rs->max_freq / rs->speed

We'll then program 0 into the SPI_BAUDR register.  The Rockchip TRM
says: "If the value is 0, the serial output clock (sclk_out) is
disabled."

It's much better to end up with the fastest possible clock rather than
a clock that is off, so enforce a minimum value.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Doug Anderson 2014-08-28 16:43:48 -07:00 committed by Mark Brown
parent 0ac7a4904a
commit 5d1d150d7d
1 changed files with 1 additions and 1 deletions
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2
drivers/spi/spi-rockchip.c
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@ -499,7 +499,7 @@ static void rockchip_spi_config(struct rockchip_spi *rs)
}
/* div doesn't support odd number */
div = rs->max_freq / rs->speed;
div = max_t(u32, rs->max_freq / rs->speed, 1);
div = (div + 1) & 0xfffe;
spi_enable_chip(rs, 0);