On 10/08/2013 12:08 PM, Stephen Warren wrote: > On 10/08/2013 10:14 AM, Nishanth Menon wrote: >> On 10/08/2013 09:39 AM, Laxman Dewangan wrote: >>> Thanks Nishanth for review. >>> >>> On Tuesday 08 October 2013 06:59 PM, Nishanth Menon wrote: >>>> On 10/08/2013 08:21 AM, Laxman Dewangan wrote: >>>>> Palmas devices has two clock output CLK32K_KG and CLK32K_KG_AUDIO >>>> not all palmas devices have 2 clocks - example: tps659038 >>> >>> This is for generic palmas and I have seen it for TPS65913, TPS65914, >>> TPS80036. If the generic one is not compatible then it need to add >>> device specific and at that time, it is require to update the binding >>> document accordingly. >> >> ?? you do have two clocks inside the device they should be represented >> as two compatible entities - that simplifies everyone's life. > > I think the terminology you're using here is quite confusing. > > Are you talking about having two different compatible values for two > different HW designs, where those different designs implement different > sets of clocks (which makes sense), or two different DT nodes for two > different clocks (which IMHO doesn't always, unless those different > clocks *truly* are separate IP blocks with completely independent > register regions, and where those IP blocks are likely to be re-used > as-is in other chips). > clk32k and clk32k_audio are two different resources and since these are two different resource instances - a "compatible" matching an actual device is my suggestion. clk32k and clk32k_audio are two different resources because they have their specific set of controls registers and may even be independently present in a Palmas variant. To highlight this: The example of tps659038 where clk32k is not present, but clk32k_audio is present (and happens to be disabled by default - thanks to an OTP on the chip - on platform like DRA7-evm, it is used to for 32k clk for wlan -currently hacked in u-boot using plain i2c writes[1] - yes it is yucky). Obviously, there are many ways to implement this. based on the current implementation, it indicates that if i create a node with "ti,palmas-clk" -i'd create two clocks - that is wrong for tps659038. Now (with the current approach), if I have to create a one clock for tps659038, i have to fix the for adding clock providers, add up "ti,tps659038-clk" etc.. it is doable - but IMHO, I dont need to do it with only the relevant nodes in dts. Further, it has no way to indicate that device X uses clock Y using clocks =<&xyz> either. [1] DRA7-evm u-boot hack. i2c dev 0 i2c probe i2c mw 0x58 0xfb 0x2b (select secondary function for GPIO_5) i2c mw 0x58 0xd5 0x01 (enable audio clock) -- Regards, Nishanth Menon -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
