Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966856Ab3HHWp1 (ORCPT ); Thu, 8 Aug 2013 18:45:27 -0400 Received: from mail-bk0-f53.google.com ([209.85.214.53]:43675 "EHLO mail-bk0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966781Ab3HHWp0 (ORCPT ); Thu, 8 Aug 2013 18:45:26 -0400 From: Tomasz Figa To: Cho KyongHo Cc: "'Linux ARM Kernel'" , "'Linux IOMMU'" , "'Linux Kernel'" , "'Linux Samsung SOC'" , devicetree@vger.kernel.org, "'Joerg Roedel'" , "'Kukjin Kim'" , "'Prathyush'" , "'Rahul Sharma'" , "'Subash Patel'" , "'Grant Grundler'" , "'Antonios Motakis'" , kvmarm@lists.cs.columbia.edu, "'Sachin Kamat'" Subject: Re: [PATCH v9 08/16] iommu/exynos: gating clocks of master H/W Date: Fri, 09 Aug 2013 00:45:17 +0200 Message-ID: <7908536.azGeeOL56k@flatron> User-Agent: KMail/4.10.5 (Linux/3.10.4-gentoo; KDE/4.10.5; x86_64; ; ) In-Reply-To: <002c01ce941b$1fd0ab80$5f720280$@samsung.com> References: <002c01ce941b$1fd0ab80$5f720280$@samsung.com> 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: 5205 Lines: 176 Hi KyongHo, On Thursday 08 of August 2013 18:39:05 Cho KyongHo wrote: > This patch gates clocks of master H/W as well as clocks of System MMU > if master clocks are specified. > > Some Exynos SoCs (i.e. GScalers in Exynos5250) have dependencies in > the gating clocks of master H/W and its System MMU. If a H/W is the > case, accessing control registers of System MMU is prohibited unless > both of the gating clocks of System MMU and its master H/W. > > Signed-off-by: Cho KyongHo > --- > drivers/iommu/exynos-iommu.c | 38 > ++++++++++++++++++++++++++++++++++---- 1 files changed, 34 > insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c > index 0ee73e8..005a7ed 100644 > --- a/drivers/iommu/exynos-iommu.c > +++ b/drivers/iommu/exynos-iommu.c > @@ -173,6 +173,7 @@ struct sysmmu_drvdata { > struct device *dev; /* Owner of system MMU */ > int nsfrs; > struct clk *clk; > + struct clk *clk_master; > int activations; > rwlock_t lock; > struct iommu_domain *domain; > @@ -263,6 +264,8 @@ void exynos_sysmmu_set_prefbuf(struct device *dev, > if (!is_sysmmu_active(data)) > goto finish; > > + clk_enable(data->clk_master); > + > for (i = 0; i < data->nsfrs; i++) { > if ((readl(data->sfrbases[i] + REG_MMU_VERSION) >> 28) == 3) { > if (!sysmmu_block(data->sfrbases[i])) > @@ -288,6 +291,8 @@ void exynos_sysmmu_set_prefbuf(struct device *dev, > sysmmu_unblock(data->sfrbases[i]); > } > } > + > + clk_disable(data->clk_master); > finish: > read_unlock_irqrestore(&data->lock, flags); > } > @@ -358,6 +363,8 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void > *dev_id) break; > } > > + clk_enable(data->clk_master); > + > if (i == pdev->num_resources) { > itype = SYSMMU_FAULT_UNKNOWN; > } else { > @@ -391,6 +398,8 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void > *dev_id) if (itype != SYSMMU_FAULT_UNKNOWN) > sysmmu_unblock(data->sfrbases[i]); > > + clk_disable(data->clk_master); > + > read_unlock(&data->lock); > > return IRQ_HANDLED; > @@ -407,11 +416,14 @@ static bool __exynos_sysmmu_disable(struct > sysmmu_drvdata *data) if (!set_sysmmu_inactive(data)) > goto finish; > > + clk_enable(data->clk_master); > + > for (i = 0; i < data->nsfrs; i++) > __raw_writel(CTRL_DISABLE, data->sfrbases[i] + REG_MMU_CTRL); > > - if (data->clk) > - clk_disable(data->clk); > + clk_disable(data->clk_master); > + > + clk_disable(data->clk); > > disabled = true; > data->pgtable = 0; > @@ -454,11 +466,12 @@ static int __exynos_sysmmu_enable(struct > sysmmu_drvdata *data, goto finish; > } > > - if (data->clk) > - clk_enable(data->clk); > + clk_enable(data->clk); > > data->pgtable = pgtable; > > + clk_enable(data->clk_master); > + > for (i = 0; i < data->nsfrs; i++) { > __sysmmu_set_ptbase(data->sfrbases[i], pgtable); > > @@ -473,6 +486,8 @@ static int __exynos_sysmmu_enable(struct > sysmmu_drvdata *data, __raw_writel(CTRL_ENABLE, data->sfrbases[i] + > REG_MMU_CTRL); } > > + clk_disable(data->clk_master); > + > data->domain = domain; > > dev_dbg(data->sysmmu, "Enabled\n"); > @@ -528,6 +543,7 @@ static void sysmmu_tlb_invalidate_entry(struct > device *dev, unsigned long iova) > > if (is_sysmmu_active(data)) { > int i; > + clk_enable(data->clk_master); > for (i = 0; i < data->nsfrs; i++) { > if (sysmmu_block(data->sfrbases[i])) { > __sysmmu_tlb_invalidate_entry( > @@ -535,6 +551,7 @@ static void sysmmu_tlb_invalidate_entry(struct > device *dev, unsigned long iova) sysmmu_unblock(data->sfrbases[i]); > } > } > + clk_disable(data->clk_master); > } else { > dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n"); > } > @@ -551,12 +568,14 @@ void exynos_sysmmu_tlb_invalidate(struct device > *dev) > > if (is_sysmmu_active(data)) { > int i; > + clk_enable(data->clk_master); > for (i = 0; i < data->nsfrs; i++) { > if (sysmmu_block(data->sfrbases[i])) { > __sysmmu_tlb_invalidate(data- >sfrbases[i]); > sysmmu_unblock(data->sfrbases[i]); > } > } > + clk_disable(data->clk_master); > } else { > dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n"); > } > @@ -637,6 +656,17 @@ static int __init exynos_sysmmu_probe(struct > platform_device *pdev) return ret; > } > > + data->clk_master = devm_clk_get(dev, "master"); > + if (IS_ERR(data->clk_master)) > + data->clk_master = NULL; > + > + ret = clk_prepare(data->clk_master); > + if (ret) { > + clk_unprepare(data->clk); > + dev_err(dev, "Failed to prepare master's clk\n"); > + return ret; > + } > + > rwlock_init(&data->lock); > INIT_LIST_HEAD(&data->node); This should be done in a more appropriate way, but at the moment the PM Core doesn't have any provision to implement any sane solution for this kind of problems, so this is fine. Reviewed-by: Tomasz Figa Best regards, Tomasz -- 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/