tree 116a0ba4981a5e54960d934e0b5339809f089b99
parent e5ca42458b6278b7d5866e08dae7c45349af2157
author Mika Westerberg <mika.westerberg@linux.intel.com> 1465562601 +0300
committer Thierry Reding <thierry.reding@gmail.com> 1468231644 +0200

pwm: lpss: Prevent on_time_div overflow on lower frequencies

If duty_ns is large enough multiplying it by 255 overflows and results
wrong duty cycle value being programmed. For example with 10ms duty when
period is 20ms (50%) we get

  255 * 10000000 / 20000000 = -87

because 255 * 10000000 overlows int. Whereas correct value should be

  255 * 10000000 / 20000000 = 127

Fix this by using unsigned long long as type for on_time_div and changing
integer literals to use proper type annotation.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>