On Friday 11 October 2013 12:23 PM, Kishon Vijay Abraham I wrote: > Hi, > > On Friday 11 October 2013 12:00 PM, Nishanth Menon wrote: >> On Fri, Oct 11, 2013 at 1:13 AM, Kishon Vijay Abraham I <kishon@xxxxxx> wrote: >>> >>>> regulator-boot-on indicates that PMIC enables it by default as part of >>>> OTP or some internal behavior -> Looking at the measurements done on >>>> uEVM and OTP information -> regulator-boot-on should be kept here. >>> >>> No. Actually I don’t want PMIC to enable it by default. I want the palmas-usb >>> driver to handle it. >>> Enabling it by default makes palmas-usb to detect VBUS interrupt. This should >>> ideally be detected only when you connect a host cable. >>> Btw I didn't exactly get why you want regulator-boot-on should be kept here. >> >> binding description states: >> - regulator-boot-on: bootloader/firmware enabled regulator >> Further info: include/linux/regulator/machine.h >> * @boot_on: Set if the regulator is enabled when the system is initially >> * started. If the regulator is not enabled by the hardware or >> * bootloader then it will be enabled when the constraints are >> * applied. >> >> What that means is that it is enabled by firmware/bootloader (in our >> case One Time Program {OTP} inside Palmas) when the system switches on >> even before the kernel starts. and we know SMPS10 is autoenabled by >> Palmas OTP configuration even before first instruction in A15 >> executes. > > Not sure about that. Please note SMPS10 has two outputs OUT1 and OUT2 and I > tend to think that it might be OUT2 that's getting enabled by the OTP. >> >> I think you misunderstand this to mean that you'd like the regulator >> to be *switched on* automatically at kernel boot by regulator >> framework - there is no reasoning why we'd want such a binding since >> we'd expect drivers to do their job of requesting and enabling >> regulators on need.. > > The comment you just quoted tells it enables the regulator if its not enabled > by hardware. "If the regulator is not enabled by the hardware or bootloader > then it will be enabled when the constraints are applied." At-least that's what > I understood from that comment. > > Also from our experiments it doesn't look like SMPS10_OUT1 is enabled by the > OTP and it gets enabled when we have *regulator-boot-on* constraints. btw.. I think this is the code in regulator fw that's responsible for enabling.. /* If the constraints say the regulator should be on at this point * and we have control then make sure it is enabled. */ if ((rdev->constraints->always_on || rdev->constraints->boot_on) && ops->enable) { ret = ops->enable(rdev); if (ret < 0) { rdev_err(rdev, "failed to enable\n"); goto out; } } Thanks Kishon -- 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