Commits
Vladimir Zapolskiy committed 10b4640833e
spi: sh-msiof: Fix bit field overflow writes to TSCR/RSCR
The change fixes a bit field overflow which allows to write to higher
bits while calculating SPI transfer clock and setting BRPS and BRDV
bit fields, the problem is reproduced if 'parent_rate' to 'spi_hz'
ratio is greater than 1024, for instance
p->min_div = 2,
MSO rate = 33333333,
SPI device rate = 10000
results in
k = 5, i.e. BRDV = 0b100 or 1/32 prescaler output,
BRPS = 105,
TSCR value = 0x6804, thus MSSEL and MSIMM bit fields are non-zero.
Fixes: 65d5665bb260 ("spi: sh-msiof: Update calculation of frequency dividing")
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>