On Thu, Apr 17, 2014 at 07:49:31AM +0000, Li.Xiubo@xxxxxxxxxxxxx wrote: > > > + ftm0: ftm@40038000 { > > > + compatible = "fsl,vf610-ftm-timer"; > > > + reg = <0x40038000 0x2000>; > > > + interrupts = <0 42 IRQ_TYPE_LEVEL_HIGH>; > > > + clock-names = "ftm0", "ftm1", > > > + "ftm0_counter_en", "ftm1_counter_en"; > > > + clocks = <&clks VF610_CLK_FTM0>, > > > + <&clks VF610_CLK_FTM1>, > > > + <&clks VF610_CLK_FTM0_EXT_FIX_EN>, > > > + <&clks VF610_CLK_FTM1_EXT_FIX_EN>; > > > + status = "disabled"; > > > > For such completely internal block which has no pins route out on board, > > we should probably just not have this "disabled" status line. > > > > Well, from IEEE 1275, there defined a standard 'status' property indicating > The operational status of one device. The 'status' property has four possible > values: 'okay/ok', 'disabled', 'fail' and 'fail-xxx'. > > If it is absent, that means the status of the device is unknown or okay. Yes, missing 'disabled' status equals to a 'okay' status from Linux implementation. Then, the device is always available in device tree, and Linux Kconfig option will control whether the driver for the device is enabled. > > If discard the status line here in vf610.dtsi, this device will be enabled > as default though 'no pins route out' on the board, and actually there has > pins route out on the board, as timer devices here we just not use it, but > as PWM devices the pins will be used. > > How about let the node disabled in vf610.dtsi, and then enable it in vf610-twr.dts > if it will be used in TWR board... ? Okay. If there is some use cases that have board level configuration like pin out, I'm fine with your existing code. Shawn -- 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