The code uses of_property_read_u32 and expects positive values. However,
the values are stored in signed int variables. Additionally, the registers
values are also stored in signed variables without a good reason
(readl/writel expect u32).
The only time this caused a real bug was in the new average-samples
property, in which the property is numerically compared and implicitly
expected to be positive.
I believe it's better to change all the properties and registers to u32,
for consistency and warnings reduction.