On 1/7/14 6:37 PM, Jaehoon Chung wrote: > Hi, Dinh. > > Sorry for replying too late. > > ..[snip].. >>>>>>>> + sdr_timing[1] = ddr_timing[1] = 1; >>>>>>>> + of_property_read_u32_array(np, >>>>>>>> + "samsung,dw-mshc-sdr-timing", sdr_timing, 2); >>>>>>>> + >>>>>>>> + of_property_read_u32_array(np, >>>>>>>> + "samsung,dw-mshc-ddr-timing", ddr_timing, 2); >>>>>>>> + >>>>>>>> + pdata->cclk_in_drv = 1; >>>>>>>> + if ((sdr_timing[1] == 0) || (ddr_timing[1] == 0)) >>>>>>>> + pdata->cclk_in_drv = 0; >>>>>>>> + >>>>>>> Have some concern about whether it is suitable putting "samsung,~" >>>>>>> property in dw_mmc.c, is it supposed to be platform related? >>>>>>> Any conflict with drivers/mmc/host/dw_mmc-exynos.c? >>>>>>> If they are really commonly used, how about change name and define in >>>>>>> Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt? >>>>>> I had submitted a patch to make this a common binding before: >>>>>> >>>>>> http://www.spinics.net/lists/devicetree/msg00638.html >>>>>> >>>>>> I think the ultimate conclusion to that thread was that its perfectly >>>>>> acceptable to re-use bindings from other >>>>>> platforms. >>>>>> >>>>> Hmm, ususally I may look for the properties of dw_mmc.c in >>>>> synopsys-dw-mshc.txt. >>>>> If this is the conclusion before, then just ignore this noise. >>>> If can be removed the samsung property, then i think property of clock >>>> timing can be used into dw-mmc.c >>>> But if samsung property is used, well. I think right that it's used into >>>> dw_mmc-exynos.c. >>>> Dw-mmc.c is general driver..so we don't want to include any SoC specific >>>> code. >>> Then do you suggest I go forward with an attempt to add a new generic >>> "snps,dw-mshc-sdr-timing" >>> binding? >> Ping Jaehoon? >> >> Do you think I need to add a generic "snps,dw-mshc-sdr-timing" and >> "snps,dw-mshc-ddr-timing" bindings then? > Well, i think it's also something wrong. ddr/sdr-timing is exynos specific > value, not synopsys value. > If synopsys use the sdr/ddr timing, then it's right that "snps, > dw-mshc-sdr/ddr-timing" is used. I went through the databook and I think that the timing values are mentioned throughout the spec. It just does not explicitly mentions ddr/sdr timing, but it is mentioned as cclk_in_drv(aka drvsel), and cclk_in_sample(aka smpsel). Even the macro in dw_mmc-exynos, SDMMC_CLKSEL_CCLK_DRIVE() and SDMMC_CLKSEL_CCLK_SAMPLE() is stating this.
So I do not believe that "samsung, dw-mshc-sdr-timing" and "samsung,dw-mshc-ddr-timing" are not exclusive to only the exynos platform. Just the fact that the SOCFPGA platform can re-use the same "samsung,dw-mshc-sdr-timing" property proves that this is not just an exynos specific value. > But i didn't see sdr/ddr timing in synopsys DoC. > I know you want to control the hold-reg bit. > But this approach is not good. The spec has a table on when to use the hold-reg bit. The conditions for using the hold-reg bit is only dependent the hold-reg hw implementation and the value of cclk_in_drv. The value of cclk_in_drv is specified by the 2nd parameter of "samsung,dw-mshc-sdr-timing". So I don't understand why you think this approach is "not good"? Thanks, Dinh > Rather, how about using the callback function for exynos specific value. > Then other SoC can also use it. > > Best Regards, > Jaehoon Chung > >> Dinh >>> Dinh >>>> If i missed something, then let me know, plz. >>>> >>>> Best Regards, >>>> Jaehoon Chung >>>>> Thanks >>>>> >>> >> >> >> -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
