Hi, On Thu, Apr 24, 2014 at 6:08 AM, Anton Tikhomirov <av.tikhomirov@xxxxxxxxxxx> wrote: > Hi, > >> Hi, >> >> > -----Original Message----- >> > From: linux-usb-owner@xxxxxxxxxxxxxxx [mailto:linux-usb- >> > owner@xxxxxxxxxxxxxxx] On Behalf Of Vivek Gautam >> > Sent: Monday, April 21, 2014 9:17 PM >> > >> > Facilitate getting required 3.3V and 1.0V VDD supply for >> > OHCI controller on Exynos. >> > >> > With patches for regulators' nodes merged in 3.15: >> > c8c253f ARM: dts: Add regulator entries to smdk5420 >> > 275dcd2 ARM: dts: add max77686 pmic node for smdk5250, >> > >> > certain perripherals will now need to ensure that, >> > they request VDD regulators in their drivers, and enable >> > them so as to make them working. >> > >> > Signed-off-by: Vivek Gautam <gautam.vivek@xxxxxxxxxxx> >> > Cc: Jingoo Han <jg1.han@xxxxxxxxxxx> >> > --- >> > >> > Based on 'usb-next' branch of Greg's usb tree. >> > >> > drivers/usb/host/ohci-exynos.c | 47 >> > ++++++++++++++++++++++++++++++++++++++++ >> > 1 file changed, 47 insertions(+) >> > >> > diff --git a/drivers/usb/host/ohci-exynos.c b/drivers/usb/host/ohci- >> > exynos.c >> > index 68588d8..e2e72a8 100644 >> > --- a/drivers/usb/host/ohci-exynos.c >> > +++ b/drivers/usb/host/ohci-exynos.c [snip] >> > static void exynos_ohci_phy_enable(struct platform_device *pdev) >> > @@ -98,6 +101,28 @@ static int exynos_ohci_probe(struct >> platform_device >> > *pdev) >> > exynos_ohci->otg = phy->otg; >> > } >> > >> > + exynos_ohci->vdd33 = devm_regulator_get(&pdev->dev, "vdd33"); >> > + if (IS_ERR(exynos_ohci->vdd33)) { >> > + err = PTR_ERR(exynos_ohci->vdd33); >> > + goto fail_regulator1; >> > + } >> > + err = regulator_enable(exynos_ohci->vdd33); >> > + if (err) { >> > + dev_err(&pdev->dev, "Failed to enable VDD33 supply\n"); >> > + goto fail_regulator1; >> > + } >> > + >> > + exynos_ohci->vdd10 = devm_regulator_get(&pdev->dev, "vdd10"); >> > + if (IS_ERR(exynos_ohci->vdd10)) { >> > + err = PTR_ERR(exynos_ohci->vdd10); >> > + goto fail_regulator2; >> > + } >> > + err = regulator_enable(exynos_ohci->vdd10); >> > + if (err) { >> > + dev_err(&pdev->dev, "Failed to enable VDD10 supply\n"); >> > + goto fail_regulator2; >> > + } >> > + >> >> Do we need to skip regulator settings together with PHY configuration >> in case of exynos5440? >> >> > skip_phy: >> > exynos_ohci->clk = devm_clk_get(&pdev->dev, "usbhost"); >> > [snip] >> > @@ -218,6 +253,18 @@ static int exynos_ohci_resume(struct device *dev) >> > struct usb_hcd *hcd = dev_get_drvdata(dev); >> > struct exynos_ohci_hcd *exynos_ohci = to_exynos_ohci(hcd); >> > struct platform_device *pdev = to_platform_device(dev); >> > + int ret; >> > + >> > + ret = regulator_enable(exynos_ohci->vdd33); >> > + if (ret) { >> > + dev_err(dev, "Failed to enable VDD33 supply\n"); >> > + return ret; >> >> Not sure, but shall we continue resuming and do everything >> we can in case of error? At least it will avoid >> WARN_ON(clk->enable_count == 0) on next system suspend. True, i will modify it. > > On the other hand, if power is not applied to the controller, > register access in ohci_resume() may lead to undefined behavior. > What's your opinion? AFA i think, it is obvious that the regulators would not work without a VDD supply. So the question is, do we have VDD LDOs available on all Exynos systems for usb ? >From the schemata of Exynos5250 and Exynos5420 boards, i can see the required VDD LDOs for USB. Unfortunately at present i don't have a Exynos4* schemata. If regulator is not a mandatory, then we can make it option similar to what Jingoo has also suggested in subsequent mail. [snip] -- Best Regards Vivek Gautam Samsung R&D Institute, Bangalore India -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
