Commit Graph

3 Commits

Author SHA1 Message Date
Heikki Krogerus 6b54783620 clk: fractional-divider: support for divider bypassing
If the divider or multiplier values are 0 in the register, bypassing the
divider and returning the parent clock rate in clk_fd_recalc_rate().

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed commitlog typo]
2015-03-12 12:18:47 -07:00
Heiko Stübner feaefa0ea1 clk: fractional-divider: cast parent_rate to u64 before multiplying
On 32bit architectures, like ARM calculating the fractional rate will
do the multiplication before converting the value to u64 when it gets
assigned to ret, which can produce overflows.

The error in question happened with a parent_rate of 386MHz, m = 3000,
n = 60000, which resulted in a wrong rate value of 15812Hz.

Therefore cast parent_rate to u64 to make sure the multiplication
happens in a 64bit space and produces the correct 192MHz in the example.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-09-10 09:42:37 -07:00
Heikki Krogerus e2d0e90fae clk: new basic clk type for fractional divider
Fractional divider clocks are fairly common. This adds basic
type for them.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-20 13:34:02 +02:00