On 05/15/2014 12:15 PM, Kishon Vijay Abraham I wrote: > Hi Nishanth, > > On Wednesday 14 May 2014 09:04 PM, Nishanth Menon wrote: >> On Wed, May 14, 2014 at 10:19 AM, Kishon Vijay Abraham I <kis...@ti.com> >> wrote: >>> Hi Roger, >>> >>> On Wednesday 14 May 2014 06:46 PM, Roger Quadros wrote: >>>> Hi Kishon, >>>> >>>> On 05/06/2014 04:33 PM, Kishon Vijay Abraham I wrote: >>>>> APLL used by PCIE phy can either use external clock as input or the clock >>>>> from DPLL. Added support for the APLL to use external clock as input here. >>>>> >>>>> Cc: Rajendra Nayak <rna...@ti.com> >>>>> Cc: Tero Kristo <t-kri...@ti.com> >>>>> Cc: Paul Walmsley <p...@pwsan.com> >>>>> Signed-off-by: Kishon Vijay Abraham I <kis...@ti.com> >>>>> --- >>>>> Documentation/devicetree/bindings/phy/ti-phy.txt | 4 ++ >>>>> drivers/phy/phy-ti-pipe3.c | 75 >>>>> ++++++++++++++-------- >>>>> 2 files changed, 52 insertions(+), 27 deletions(-) >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/phy/ti-phy.txt >>>>> b/Documentation/devicetree/bindings/phy/ti-phy.txt >>>>> index bc9afb5..d50f8ee 100644 >>>>> --- a/Documentation/devicetree/bindings/phy/ti-phy.txt >>>>> +++ b/Documentation/devicetree/bindings/phy/ti-phy.txt >>>>> @@ -76,6 +76,10 @@ Required properties: >>>>> * "dpll_ref_m2" - external dpll ref clk >>>>> * "phy-div" - divider for apll >>>>> * "div-clk" - apll clock >>>>> + * "apll_mux" - mux for pcie apll >>>>> + * "refclk_ext" - external reference clock for pcie apll >>>>> + - ti,ext-clk: To specifiy if PCIE apll should use external clock. >>>>> Applicable >>>>> + only to PCIE PHY. >>>> >>>> Instead of specifying both clock sources "dpll_ref_clock", "refclk_ext" >>>> and then specifying a 3rd control option "ti,ext-clk" to select one of the >>>> 2 sources, why can't the DT just supply one clock source, i.e. the one >>>> that is being used in the board instance? The driver should then just >>>> configure the clock rate that is needed at that node. Shouldn't the clock >>>> framework automatically take care of muxing and parent rates? >>> >>> Want the dt to have all the clocks used by the controller. "ti,ext-clk" >>> should >>> go in the board dt file (suggested by Nishanth). >>> The point is at some point later if some one wants to change the clock >>> source, >>> it should be a simple enabling "ti,ext-clk" flag instead of finding the >>> clock >>> phandle etc.. >> >> Wonder if that is implicit by the presence of "refclk_ext" in the >> clocks provided? > > IMO the presence of "refclk_ext" is useless unless the board indicates it > provides the clock source. > > refclk_ext holds phandle for *fixed-clock*, so irrespective of whether the > board provides a clock or not, it can have that handle for configuring in > PRCM. > However if the board does not provide the clock source, configuring refclk_ext > in PRCM is useless.
I think what Nishant meant is that if "refclk_ext" is provided it means that the driver should use that over "dpll_ref_clock" so no need of a separate "ti,ext-clk" flag. cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
