On Mon, December 16, 2013, Zhangfei Gao wrote: > Dear Seungwon > > On 12/16/2013 11:50 AM, Seungwon Jeon wrote: > > On Sat, December 14, 2013, Zhangfei Gao wrote: > > >> + /* SoC portion */ > >> + dwmmc_0: dwmmc0@fcd03000 { > >> + compatible = "hisilicon,hi4511-dw-mshc"; > >> + reg = <0xfcd03000 0x1000>; > >> + interrupts = <0 16 4>; > >> + #address-cells = <1>; > >> + #size-cells = <0>; > >> + clocks = <&mmc_clock HI3620_SD_CIUCLK>, <&clock HI3620_DDRC_PER_CLK>; > >> + clock-names = "ciu", "biu"; > >> + clock-freq-table = > >> + <25000000 0 50000000 25000000 50000000 100000000 0 50000000>; > > I think it could be solved with mmc->f_min and mmc->f_max(from clock-freq-min-max property) > > if there is no limitation per each speed mode. As seeing described table, it looks that. > > Have tried them before, but unfortunately, they are different. > > The controller can not generate clock itself, while depending on the > outside clock generator, which may require to change clock source in > differnt mode. > > The value we want is set the capacibility of the clock input and the max > clock freq where mmc works stable in that mode, which may be different > in different mode. > > clock-freq-min-max will set the value for set_ios. > For example, we use 25M as clock capability when init, which can not be > set as freq-min, and used as set_ios, where 400K should be used, > otherwise init definitely fail. Can you check 'f_init' within 'drivers/mmc/core/core.c' file? If you set 'f_min = 25000000' for init-sequence, mmc_set_ios() will pass that rate through 'ios.clock' Then, dw_mmc-k3 can do clk_set_rate() with 25MHz at dw_mci_k3_set_ios(). And other required speeds for each mode seem not specific compared with standard spec. Also clk_set_rate() would be possible with 'ios.clock' instead of specific table. I just referred your example's clock-freq-table above. > > >> +static int dw_mci_k3_suspend(struct device *dev) > >> +{ > >> + struct dw_mci *host = dev_get_drvdata(dev); > >> + > >> + if (!IS_ERR(host->ciu_clk)) > >> + clk_disable_unprepare(host->ciu_clk); > >> + > >> + return dw_mci_suspend(host); > > If k3 needs clk_disable here, dw_mci_suspend()is expected to be called prior to > clk_disable_unprepare()? > > Of course, it's ok at present though. > > > > Sure, it can be switched, though dw_mci_suspend does nothing related > with clock now. Yes, but if some works with ciu_clk is added in dw_mci_suspend(), it will affect. Thanks, Seungwon Jeon -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html