On Thu, May 15, 2014 at 4:25 AM, Roger Quadros <rog...@ti.com> wrote: > 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.
yes, thank you for clarifying - it does indeed redundant to have "ti,ext-clk". and apologies on being a little obscure in the comment. Regards, Nishanth Menon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
