Re: [PATCH v3 1/2] clk: add clk accuracy retrieval support

2013-12-19 Thread boris brezillon
Le 19/12/2013 20:36, Mike Turquette a écrit : Quoting boris brezillon (2013-12-19 00:54:07) Hello Mike, On 19/12/2013 07:04, Mike Turquette wrote: Quoting Boris BREZILLON (2013-12-17 06:36:22) +unsigned long __clk_get_accuracy(struct clk *clk) +{ + unsigned long ret; + + if (!clk)

Re: [PATCH v3 1/2] clk: add clk accuracy retrieval support

2013-12-19 Thread boris brezillon
Hello Mike, On 19/12/2013 07:04, Mike Turquette wrote: Quoting Boris BREZILLON (2013-12-17 06:36:22) +unsigned long __clk_get_accuracy(struct clk *clk) +{ + unsigned long ret; + + if (!clk) + return 0; + + return clk->accuracy; +} +EXPORT_SYMBOL_GPL(__clk_get_acc

[PATCH v3 1/2] clk: add clk accuracy retrieval support

2013-12-17 Thread Boris BREZILLON
The clock accuracy is expressed in ppb (parts per billion) and represents the possible clock drift. Say you have a clock (e.g. an oscillator) which provides a fixed clock of 20MHz with an accuracy of +- 20Hz. This accuracy expressed in ppb is 20Hz/20MHz = 1000 ppb (or 1 ppm). Clock users may need