Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932597AbaFKPjO (ORCPT ); Wed, 11 Jun 2014 11:39:14 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:42529 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755747AbaFKPjL (ORCPT ); Wed, 11 Jun 2014 11:39:11 -0400 Date: Wed, 11 Jun 2014 11:39:10 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Vivek Gautam cc: linux-usb@vger.kernel.org, , , , , , Jingoo Han Subject: Re: [PATCH v2 1/2] usb: ehci-exynos: Make provision for vdd regulators In-Reply-To: <1402064411-18244-1-git-send-email-gautam.vivek@samsung.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 6 Jun 2014, Vivek Gautam wrote: > Facilitate getting required 3.3V and 1.0V VDD supply for > EHCI 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. "Certain peripherals"? Don't you mean "certain controllers"? Does this mean some controllers don't need to use the VDD regulators? > @@ -193,7 +196,31 @@ static int exynos_ehci_probe(struct platform_device *pdev) > > err = exynos_ehci_get_phy(&pdev->dev, exynos_ehci); > if (err) > - goto fail_clk; > + goto fail_regulator1; > + > + exynos_ehci->vdd33 = devm_regulator_get(&pdev->dev, "vdd33"); > + if (!IS_ERR(exynos_ehci->vdd33)) { > + err = regulator_enable(exynos_ehci->vdd33); > + if (err) { > + dev_err(&pdev->dev, > + "Failed to enable 3.3V Vdd supply\n"); > + goto fail_regulator1; > + } > + } else { > + dev_warn(&pdev->dev, "Regulator 3.3V Vdd supply not found\n"); > + } What if this is one of the controllers that don't need to use a VDD regulator? Do you really want to print out a warning in that case? Should you call devm_regulator_get_optional() instead? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/