Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756445Ab3FGRmK (ORCPT ); Fri, 7 Jun 2013 13:42:10 -0400 Received: from mail-bk0-f54.google.com ([209.85.214.54]:35314 "EHLO mail-bk0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754981Ab3FGRmI (ORCPT ); Fri, 7 Jun 2013 13:42:08 -0400 From: Tomasz Figa To: Doug Anderson Cc: Chris Ball , Olof Johansson , Andrew Bresticker , Alim Akhtar , Abhilash Kesavan , Jaehoon Chung , Seungwon Jeon , Grant Likely , Rob Herring , Rob Landley , Will Newton , devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org Subject: Re: [PATCH v2 1/2] mmc: dw_mmc: Handle late vmmc regulators with EPROBE_DEFER Date: Fri, 07 Jun 2013 19:42:03 +0200 Message-ID: <2536139.bTRcfOkXer@flatron> User-Agent: KMail/4.10.4 (Linux/3.9.4-gentoo; KDE/4.10.4; x86_64; ; ) In-Reply-To: <1370626110-1731-1-git-send-email-dianders@chromium.org> References: <1370580406-10254-1-git-send-email-dianders@chromium.org> <1370626110-1731-1-git-send-email-dianders@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4669 Lines: 144 On Friday 07 of June 2013 10:28:29 Doug Anderson wrote: > It is possible to specify a regulator that should be turned on when > dw_mmc is probed. At the moment dw_mmc will fail to use the regulator > properly if the regulator probes after dw_mmc. Fix this problem by > honoring EPROBE_DEFER. > > At the same time move the regulator code out of the slot init code. > We only specify one regulator for the whole device A question just out of curiousity: Is it really correct to have one vmmc regulator for the whole device, instead of one regulator per slot? This might be something obvious, but I don't know any details about dw_mmc, so sorry if it's the case. Best regards, Tomasz > and other parts of > the code (like suspend/resume) assume that the regulator has only been > enabled once. > > Signed-off-by: Doug Anderson > --- > Changes in v2: > - Avoid hackery to detect regulators that will never show up. > - Move regulator out of slot init--it doesn't belong there. > > .../devicetree/bindings/mmc/synopsis-dw-mshc.txt | 4 +++ > drivers/mmc/host/dw_mmc.c | 40 > ++++++++++++---------- 2 files changed, 25 insertions(+), 19 > deletions(-) > > diff --git a/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt > b/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt index > 726fd21..d5cc94e 100644 > --- a/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt > +++ b/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt > @@ -55,6 +55,9 @@ Optional properties: > > * broken-cd: as documented in mmc core bindings. > > +* vmmc-supply: The phandle to the regulator to use for vmmc. If this > is + specified we'll defer probe until we can find this regulator. + > Aliases: > > - All the MSHC controller nodes should be represented in the aliases > node using @@ -79,6 +82,7 @@ board specific portions as listed below. > broken-cd; > fifo-depth = <0x80>; > card-detect-delay = <200>; > + vmmc-supply = <&buck8>; > > slot@0 { > reg = <0>; > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index bc3a1bc..ab5642d 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -1895,7 +1895,7 @@ static int dw_mci_init_slot(struct dw_mci *host, > unsigned int id) struct mmc_host *mmc; > struct dw_mci_slot *slot; > const struct dw_mci_drv_data *drv_data = host->drv_data; > - int ctrl_id, ret; > + int ctrl_id; > u8 bus_width; > > mmc = mmc_alloc_host(sizeof(struct dw_mci_slot), host->dev); > @@ -1985,19 +1985,6 @@ static int dw_mci_init_slot(struct dw_mci *host, > unsigned int id) #endif /* CONFIG_MMC_DW_IDMAC */ > } > > - host->vmmc = devm_regulator_get(mmc_dev(mmc), "vmmc"); > - if (IS_ERR(host->vmmc)) { > - pr_info("%s: no vmmc regulator found\n", mmc_hostname(mmc)); > - host->vmmc = NULL; > - } else { > - ret = regulator_enable(host->vmmc); > - if (ret) { > - dev_err(host->dev, > - "failed to enable regulator: %d\n", ret); > - goto err_setup_bus; > - } > - } > - > if (dw_mci_get_cd(mmc)) > set_bit(DW_MMC_CARD_PRESENT, &slot->flags); > else > @@ -2023,10 +2010,6 @@ static int dw_mci_init_slot(struct dw_mci *host, > unsigned int id) queue_work(host->card_workqueue, &host->card_work); > > return 0; > - > -err_setup_bus: > - mmc_free_host(mmc); > - return -EINVAL; > } > > static void dw_mci_cleanup_slot(struct dw_mci_slot *slot, unsigned int > id) @@ -2229,11 +2212,29 @@ int dw_mci_probe(struct dw_mci *host) > } > } > > + host->vmmc = devm_regulator_get(host->dev, "vmmc"); > + if (IS_ERR(host->vmmc)) { > + ret = PTR_ERR(host->vmmc); > + if (ret == -EPROBE_DEFER) > + goto err_clk_ciu; > + > + dev_info(host->dev, "no vmmc regulator found: %d\n", ret); > + host->vmmc = NULL; > + } else { > + ret = regulator_enable(host->vmmc); > + if (ret) { > + if (ret != -EPROBE_DEFER) > + dev_err(host->dev, > + "regulator_enable fail: %d\n", ret); > + goto err_clk_ciu; > + } > + } > + > if (!host->bus_hz) { > dev_err(host->dev, > "Platform data must supply bus speed\n"); > ret = -ENODEV; > - goto err_clk_ciu; > + goto err_regulator; > } > > host->quirks = host->pdata->quirks; > @@ -2378,6 +2379,7 @@ err_dmaunmap: > if (host->use_dma && host->dma_ops->exit) > host->dma_ops->exit(host); > > +err_regulator: > if (host->vmmc) > regulator_disable(host->vmmc); -- 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/