From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:54945 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751185AbcCKR7A (ORCPT ); Fri, 11 Mar 2016 12:59:00 -0500 Date: Fri, 11 Mar 2016 11:58:50 -0600 From: Bjorn Helgaas To: Christoph Fritz Cc: Richard Zhu , Lucas Stach , Shawn Guo , Fabio Estevam , Bjorn Helgaas , Lee Jones , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3 2/2] PCI: imx6: add initial imx6sx support Message-ID: <20160311175850.GA4725@localhost> References: <1456411669-4699-1-git-send-email-chf.fritz@googlemail.com> <1456411669-4699-3-git-send-email-chf.fritz@googlemail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1456411669-4699-3-git-send-email-chf.fritz@googlemail.com> Sender: linux-pci-owner@vger.kernel.org List-ID: Hi Christoph (and Lee; there's a question for you below, too), On Thu, Feb 25, 2016 at 03:47:49PM +0100, Christoph Fritz wrote: > This patch adds initial PCIe support for the imx6 SoC derivate imx6sx. > PCI_MSI support is untested as its necessary suspend/resume quirk is > left out of this patch. > This patch is heavily based on patches by Richard Zhu. > > Signed-off-by: Christoph Fritz > --- > .../devicetree/bindings/pci/fsl,imx6q-pcie.txt | 6 +- > drivers/pci/host/pci-imx6.c | 130 ++++++++++++++------- > 2 files changed, 96 insertions(+), 40 deletions(-) > > diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt > index 6fbba53..c4323be 100644 > --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt > +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt > @@ -4,7 +4,7 @@ This PCIe host controller is based on the Synopsis Designware PCIe IP > and thus inherits all the common properties defined in designware-pcie.txt. > > Required properties: > -- compatible: "fsl,imx6q-pcie" > +- compatible: "fsl,imx6q-pcie", "fsl,imx6sx-pcie" > - reg: base addresse and length of the pcie controller I folded in a typo fix for "addresse". > - interrupts: A list of interrupt outputs of the controller. Must contain an > entry for each entry in the interrupt-names property. > @@ -13,6 +13,10 @@ Required properties: > - clock-names: Must include the following additional entries: > - "pcie_phy" > > +Additional required properties for imx6sx-pcie: > +- clock names: Must include the following additional entries: > + - "pcie_inbound_axi" > + > Example: > > pcie@0x01000000 { > diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c > index fe60096..7e634a6 100644 > --- a/drivers/pci/host/pci-imx6.c > +++ b/drivers/pci/host/pci-imx6.c > @@ -35,9 +35,11 @@ struct imx6_pcie { > struct gpio_desc *reset_gpio; > struct clk *pcie_bus; > struct clk *pcie_phy; > + struct clk *pcie_inbound_axi; > struct clk *pcie; > struct pcie_port pp; > struct regmap *iomuxc_gpr; > + bool is_imx6sx; > void __iomem *mem_base; > }; > > @@ -214,35 +216,46 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp) > struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); > u32 val, gpr1, gpr12; > > - /* > - * If the bootloader already enabled the link we need some special > - * handling to get the core back into a state where it is safe to > - * touch it for configuration. As there is no dedicated reset signal > - * wired up for MX6QDL, we need to manually force LTSSM into "detect" > - * state before completely disabling LTSSM, which is a prerequisite > - * for core configuration. > - * > - * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong > - * indication that the bootloader activated the link. > - */ > - regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1); > - regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12); > - > - if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) && > - (gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) { > - val = readl(pp->dbi_base + PCIE_PL_PFLR); > - val &= ~PCIE_PL_PFLR_LINK_STATE_MASK; > - val |= PCIE_PL_PFLR_FORCE_LINK; > - writel(val, pp->dbi_base + PCIE_PL_PFLR); > - > + if (imx6_pcie->is_imx6sx) { > regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > - IMX6Q_GPR12_PCIE_CTL_2, 0 << 10); > - } > + IMX6SX_GPR12_PCIE_TEST_POWERDOWN, > + IMX6SX_GPR12_PCIE_TEST_POWERDOWN); > + /* Force PCIe PHY reset */ > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5, > + IMX6SX_GPR5_PCIE_BTNRST_RESET, > + IMX6SX_GPR5_PCIE_BTNRST_RESET); Since there's nothing after the "else" clause, I think it's better to return immediately here. Then we don't have extra diffs that merely indent the original function. I did make this change (I'll attach my resulting patch), and that made some other changes to the indented code more visible. > + } else { > + /* > + * If the bootloader already enabled the link we need some > + * special handling to get the core back into a state where > + * it is safe to touch it for configuration. As there is no > + * dedicated reset signal to manually force LTSSM into "detect" > + * state before completely disabling LTSSM, which is a > + * prerequisite for core configuration. For example, you changed this comment, and now the last sentence is no longer a sentence. I don't know if this was an editing mistake or if this comment really does need to change. If it does need to change, it needs to stay a sentence. > + * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have > + * a strong indication that the bootloader activated the link. > + */ > + regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1); > + regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12); > + > + if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) && > + (gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) { > + val = readl(pp->dbi_base + PCIE_PL_PFLR); > + val &= ~PCIE_PL_PFLR_LINK_STATE_MASK; > + val |= PCIE_PL_PFLR_FORCE_LINK; > + writel(val, pp->dbi_base + PCIE_PL_PFLR); > + > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > + IMX6Q_GPR12_PCIE_CTL_2, 0); > + } > > - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > - IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18); > - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > - IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16); > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > + IMX6Q_GPR1_PCIE_TEST_PD, > + IMX6Q_GPR1_PCIE_TEST_PD); > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > + IMX6Q_GPR1_PCIE_REF_CLK_EN, 0); And there are subtle changes here (changing "1 << 18" to IMX6Q_GPR1_PCIE_TEST_PD, etc.) These are fine, but should be in a separate patch because (a) they're not related to imx6sx and (b) it makes them obvious and easy to review. As it is, they just get snuck in under the radar. > + } > > return 0; > } > @@ -270,18 +283,30 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) > goto err_pcie; > } > > - /* power up core phy and enable ref clock */ > - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > - IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); > - /* > - * the async reset input need ref clock to sync internally, > - * when the ref clock comes after reset, internal synced > - * reset time is too short, cannot meet the requirement. > - * add one ~10us delay here. > - */ > - udelay(10); > - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > - IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16); > + if (imx6_pcie->is_imx6sx) { > + ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi); > + if (ret) { > + dev_err(pp->dev, "unable to enable pcie_axi clock\n"); > + goto err_inbound_axi; > + } > + > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > + IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0); > + } else { > + /* power up core phy and enable ref clock */ > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > + IMX6Q_GPR1_PCIE_TEST_PD, 0); > + /* > + * the async reset input need ref clock to sync internally, > + * when the ref clock comes after reset, internal synced > + * reset time is too short , cannot meet the requirement. > + * add one ~10us delay here. > + */ > + udelay(10); > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > + IMX6Q_GPR1_PCIE_REF_CLK_EN, > + IMX6Q_GPR1_PCIE_REF_CLK_EN); > + } Here again the diff is bigger than necessary because it re-indents the original code (and makes another unrelated "1 << 16" to IMX6Q_GPR1_PCIE_REF_CLK_EN change). I'll show a different proposal in my patch below. > /* allow the clocks to stabilize */ > usleep_range(200, 500); > @@ -292,8 +317,15 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) > msleep(100); > gpiod_set_value_cansleep(imx6_pcie->reset_gpio, 1); > } > + > + if (imx6_pcie->is_imx6sx) > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5, > + IMX6SX_GPR5_PCIE_BTNRST_RESET, 0); > + > return 0; > > +err_inbound_axi: > + clk_disable_unprepare(imx6_pcie->pcie); > err_pcie: > clk_disable_unprepare(imx6_pcie->pcie_bus); > err_pcie_bus: > @@ -307,6 +339,12 @@ static void imx6_pcie_init_phy(struct pcie_port *pp) > { > struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); > > + if (imx6_pcie->is_imx6sx) { > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > + IMX6SX_GPR12_PCIE_RX_EQ_MASK, > + IMX6SX_GPR12_PCIE_RX_EQ_2); I see that you added definitions for IMX6SX_GPR12_PCIE_RX_EQ_MASK and IMX6SX_GPR12_PCIE_RX_EQ_2 in the first patch of this series, but doing that separately creates a merge problem. I can't put this change in my tree by itself because it won't build. If Lee applied the first patch to a git branch, I guess I could pull that into my tree. But it would be far simpler to just include those new definitions in this patch. > + } > + > regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > IMX6Q_GPR12_PCIE_CTL_2, 0 << 10); > > @@ -571,6 +609,9 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) > pp = &imx6_pcie->pp; > pp->dev = &pdev->dev; > > + imx6_pcie->is_imx6sx = of_device_is_compatible(pp->dev->of_node, > + "fsl,imx6sx-pcie"); > + > /* Added for PCI abort handling */ > hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0, > "imprecise external abort"); > @@ -606,6 +647,16 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) > return PTR_ERR(imx6_pcie->pcie); > } > > + if (imx6_pcie->is_imx6sx) { > + imx6_pcie->pcie_inbound_axi = devm_clk_get(&pdev->dev, > + "pcie_inbound_axi"); > + if (IS_ERR(imx6_pcie->pcie_inbound_axi)) { > + dev_err(&pdev->dev, > + "pcie_incbound_axi clock missing or invalid\n"); > + return PTR_ERR(imx6_pcie->pcie_inbound_axi); > + } > + } > + > /* Grab GPR config register range */ > imx6_pcie->iomuxc_gpr = > syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr"); > @@ -632,6 +683,7 @@ static void imx6_pcie_shutdown(struct platform_device *pdev) > > static const struct of_device_id imx6_pcie_of_match[] = { > { .compatible = "fsl,imx6q-pcie", }, > + { .compatible = "fsl,imx6sx-pcie", }, > {}, > }; > MODULE_DEVICE_TABLE(of, imx6_pcie_of_match); The patches below are what I currently have in my tree, but they're not ready for v4.6 (yet). Note that the second one is very clearly imx6sx-only. It's obvious there are no tweaks to the existing imx6 code, which makes it easier to review, backport, bisect, revert, etc. Obviously, I can't apply these directly. First we have to: - Fix the LTSSM comment - Figure out how to get the IMX6SX_GPR12_PCIE_RX_EQ_MASK definitions commit 78abf60b815a8f28207d029d61f7809647faa43a Author: Bjorn Helgaas Date: Fri Mar 11 11:15:36 2016 -0600 PCI: imx6: Factor out ref clock enable Factor out ref clock enable to make it cleaner to add imx6sx support. No functional change intended. Signed-off-by: Bjorn Helgaas diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c index 8c9b389..ecc8537 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -269,6 +269,23 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp) return 0; } +static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie) +{ + /* power up core phy and enable ref clock */ + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, + IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); + /* + * the async reset input need ref clock to sync internally, + * when the ref clock comes after reset, internal synced + * reset time is too short, cannot meet the requirement. + * add one ~10us delay here. + */ + udelay(10); + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, + IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16); + return 0; +} + static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) { struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); @@ -292,18 +309,11 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) goto err_pcie; } - /* power up core phy and enable ref clock */ - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, - IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); - /* - * the async reset input need ref clock to sync internally, - * when the ref clock comes after reset, internal synced - * reset time is too short, cannot meet the requirement. - * add one ~10us delay here. - */ - udelay(10); - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, - IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16); + ret = imx6_pcie_enable_ref_clk(imx6_pcie); + if (ret) + dev_err(pp->dev, "unable to enable pcie ref clock\n"); + goto err_ref_clk; + } /* allow the clocks to stabilize */ usleep_range(200, 500); @@ -316,6 +326,8 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) } return 0; +err_ref_clk: + clk_disable_unprepare(imx6_pcie->pcie); err_pcie: clk_disable_unprepare(imx6_pcie->pcie_bus); err_pcie_bus: commit d061033570b7fd22a3ed8c029d4793e5df7324e1 Author: Christoph Fritz Date: Thu Mar 10 15:04:25 2016 -0600 PCI: imx6: Add initial imx6sx support Add initial PCIe support for the imx6 SoC derivate imx6sx. PCI MSI support is untested as the necessary suspend/resume quirk is not included in this patch. This patch is heavily based on patches by Richard Zhu. [bhelgaas: factor out refclk enable, fix adjacent typos in fsl,imx6q-pcie.txt] Signed-off-by: Christoph Fritz Acked-by: Richard Zhu Acked-by: Lucas Stach diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt index 3be80c6..0561e88 100644 --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt @@ -4,8 +4,8 @@ This PCIe host controller is based on the Synopsis Designware PCIe IP and thus inherits all the common properties defined in designware-pcie.txt. Required properties: -- compatible: "fsl,imx6q-pcie" -- reg: base addresse and length of the pcie controller +- compatible: "fsl,imx6q-pcie", "fsl,imx6sx-pcie" +- reg: base address and length of the PCIe controller - interrupts: A list of interrupt outputs of the controller. Must contain an entry for each entry in the interrupt-names property. - interrupt-names: Must include the following entries: @@ -20,6 +20,10 @@ Optional properties: - fsl,tx-swing-full: Gen2 TX SWING FULL value. Default: 127 - fsl,tx-swing-low: TX launch amplitude swing_low value. Default: 127 +Additional required properties for imx6sx-pcie: +- clock names: Must include the following additional entries: + - "pcie_inbound_axi" + Example: pcie@0x01000000 { diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c index ecc8537..4d6af21 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -35,9 +35,11 @@ struct imx6_pcie { struct gpio_desc *reset_gpio; struct clk *pcie_bus; struct clk *pcie_phy; + struct clk *pcie_inbound_axi; struct clk *pcie; struct pcie_port pp; struct regmap *iomuxc_gpr; + bool is_imx6sx; void __iomem *mem_base; u32 tx_deemph_gen1; u32 tx_deemph_gen2_3p5db; @@ -236,13 +238,23 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp) struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); u32 val, gpr1, gpr12; + if (imx6_pcie->is_imx6sx) { + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, + IMX6SX_GPR12_PCIE_TEST_POWERDOWN, + IMX6SX_GPR12_PCIE_TEST_POWERDOWN); + /* Force PCIe PHY reset */ + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5, + IMX6SX_GPR5_PCIE_BTNRST_RESET, + IMX6SX_GPR5_PCIE_BTNRST_RESET); + return 0; + } + /* * If the bootloader already enabled the link we need some special * handling to get the core back into a state where it is safe to * touch it for configuration. As there is no dedicated reset signal - * wired up for MX6QDL, we need to manually force LTSSM into "detect" - * state before completely disabling LTSSM, which is a prerequisite - * for core configuration. + * to manually force LTSSM into "detect" state before completely + * disabling LTSSM, which is a prerequisite for core configuration. * * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong * indication that the bootloader activated the link. @@ -271,6 +283,18 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp) static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie) { + if (imx6_pcie->is_imx6sx) { + ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi); + if (ret) { + dev_err(pp->dev, "unable to enable pcie_axi clock\n"); + return ret; + } + + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, + IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0); + return 0; + } + /* power up core phy and enable ref clock */ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); @@ -324,6 +348,11 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) msleep(100); gpiod_set_value_cansleep(imx6_pcie->reset_gpio, 1); } + + if (imx6_pcie->is_imx6sx) + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5, + IMX6SX_GPR5_PCIE_BTNRST_RESET, 0); + return 0; err_ref_clk: @@ -341,6 +370,12 @@ static void imx6_pcie_init_phy(struct pcie_port *pp) { struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); + if (imx6_pcie->is_imx6sx) { + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, + IMX6SX_GPR12_PCIE_RX_EQ_MASK, + IMX6SX_GPR12_PCIE_RX_EQ_2); + } + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6Q_GPR12_PCIE_CTL_2, 0 << 10); @@ -565,6 +600,9 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) pp = &imx6_pcie->pp; pp->dev = &pdev->dev; + imx6_pcie->is_imx6sx = of_device_is_compatible(pp->dev->of_node, + "fsl,imx6sx-pcie"); + /* Added for PCI abort handling */ hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0, "imprecise external abort"); @@ -600,6 +638,16 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) return PTR_ERR(imx6_pcie->pcie); } + if (imx6_pcie->is_imx6sx) { + imx6_pcie->pcie_inbound_axi = devm_clk_get(&pdev->dev, + "pcie_inbound_axi"); + if (IS_ERR(imx6_pcie->pcie_inbound_axi)) { + dev_err(&pdev->dev, + "pcie_incbound_axi clock missing or invalid\n"); + return PTR_ERR(imx6_pcie->pcie_inbound_axi); + } + } + /* Grab GPR config register range */ imx6_pcie->iomuxc_gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr"); @@ -647,6 +695,7 @@ static void imx6_pcie_shutdown(struct platform_device *pdev) static const struct of_device_id imx6_pcie_of_match[] = { { .compatible = "fsl,imx6q-pcie", }, + { .compatible = "fsl,imx6sx-pcie", }, {}, }; MODULE_DEVICE_TABLE(of, imx6_pcie_of_match); From mboxrd@z Thu Jan 1 00:00:00 1970 From: helgaas@kernel.org (Bjorn Helgaas) Date: Fri, 11 Mar 2016 11:58:50 -0600 Subject: [PATCH v3 2/2] PCI: imx6: add initial imx6sx support In-Reply-To: <1456411669-4699-3-git-send-email-chf.fritz@googlemail.com> References: <1456411669-4699-1-git-send-email-chf.fritz@googlemail.com> <1456411669-4699-3-git-send-email-chf.fritz@googlemail.com> Message-ID: <20160311175850.GA4725@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Christoph (and Lee; there's a question for you below, too), On Thu, Feb 25, 2016 at 03:47:49PM +0100, Christoph Fritz wrote: > This patch adds initial PCIe support for the imx6 SoC derivate imx6sx. > PCI_MSI support is untested as its necessary suspend/resume quirk is > left out of this patch. > This patch is heavily based on patches by Richard Zhu. > > Signed-off-by: Christoph Fritz > --- > .../devicetree/bindings/pci/fsl,imx6q-pcie.txt | 6 +- > drivers/pci/host/pci-imx6.c | 130 ++++++++++++++------- > 2 files changed, 96 insertions(+), 40 deletions(-) > > diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt > index 6fbba53..c4323be 100644 > --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt > +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt > @@ -4,7 +4,7 @@ This PCIe host controller is based on the Synopsis Designware PCIe IP > and thus inherits all the common properties defined in designware-pcie.txt. > > Required properties: > -- compatible: "fsl,imx6q-pcie" > +- compatible: "fsl,imx6q-pcie", "fsl,imx6sx-pcie" > - reg: base addresse and length of the pcie controller I folded in a typo fix for "addresse". > - interrupts: A list of interrupt outputs of the controller. Must contain an > entry for each entry in the interrupt-names property. > @@ -13,6 +13,10 @@ Required properties: > - clock-names: Must include the following additional entries: > - "pcie_phy" > > +Additional required properties for imx6sx-pcie: > +- clock names: Must include the following additional entries: > + - "pcie_inbound_axi" > + > Example: > > pcie at 0x01000000 { > diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c > index fe60096..7e634a6 100644 > --- a/drivers/pci/host/pci-imx6.c > +++ b/drivers/pci/host/pci-imx6.c > @@ -35,9 +35,11 @@ struct imx6_pcie { > struct gpio_desc *reset_gpio; > struct clk *pcie_bus; > struct clk *pcie_phy; > + struct clk *pcie_inbound_axi; > struct clk *pcie; > struct pcie_port pp; > struct regmap *iomuxc_gpr; > + bool is_imx6sx; > void __iomem *mem_base; > }; > > @@ -214,35 +216,46 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp) > struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); > u32 val, gpr1, gpr12; > > - /* > - * If the bootloader already enabled the link we need some special > - * handling to get the core back into a state where it is safe to > - * touch it for configuration. As there is no dedicated reset signal > - * wired up for MX6QDL, we need to manually force LTSSM into "detect" > - * state before completely disabling LTSSM, which is a prerequisite > - * for core configuration. > - * > - * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong > - * indication that the bootloader activated the link. > - */ > - regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1); > - regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12); > - > - if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) && > - (gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) { > - val = readl(pp->dbi_base + PCIE_PL_PFLR); > - val &= ~PCIE_PL_PFLR_LINK_STATE_MASK; > - val |= PCIE_PL_PFLR_FORCE_LINK; > - writel(val, pp->dbi_base + PCIE_PL_PFLR); > - > + if (imx6_pcie->is_imx6sx) { > regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > - IMX6Q_GPR12_PCIE_CTL_2, 0 << 10); > - } > + IMX6SX_GPR12_PCIE_TEST_POWERDOWN, > + IMX6SX_GPR12_PCIE_TEST_POWERDOWN); > + /* Force PCIe PHY reset */ > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5, > + IMX6SX_GPR5_PCIE_BTNRST_RESET, > + IMX6SX_GPR5_PCIE_BTNRST_RESET); Since there's nothing after the "else" clause, I think it's better to return immediately here. Then we don't have extra diffs that merely indent the original function. I did make this change (I'll attach my resulting patch), and that made some other changes to the indented code more visible. > + } else { > + /* > + * If the bootloader already enabled the link we need some > + * special handling to get the core back into a state where > + * it is safe to touch it for configuration. As there is no > + * dedicated reset signal to manually force LTSSM into "detect" > + * state before completely disabling LTSSM, which is a > + * prerequisite for core configuration. For example, you changed this comment, and now the last sentence is no longer a sentence. I don't know if this was an editing mistake or if this comment really does need to change. If it does need to change, it needs to stay a sentence. > + * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have > + * a strong indication that the bootloader activated the link. > + */ > + regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1); > + regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12); > + > + if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) && > + (gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) { > + val = readl(pp->dbi_base + PCIE_PL_PFLR); > + val &= ~PCIE_PL_PFLR_LINK_STATE_MASK; > + val |= PCIE_PL_PFLR_FORCE_LINK; > + writel(val, pp->dbi_base + PCIE_PL_PFLR); > + > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > + IMX6Q_GPR12_PCIE_CTL_2, 0); > + } > > - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > - IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18); > - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > - IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16); > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > + IMX6Q_GPR1_PCIE_TEST_PD, > + IMX6Q_GPR1_PCIE_TEST_PD); > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > + IMX6Q_GPR1_PCIE_REF_CLK_EN, 0); And there are subtle changes here (changing "1 << 18" to IMX6Q_GPR1_PCIE_TEST_PD, etc.) These are fine, but should be in a separate patch because (a) they're not related to imx6sx and (b) it makes them obvious and easy to review. As it is, they just get snuck in under the radar. > + } > > return 0; > } > @@ -270,18 +283,30 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) > goto err_pcie; > } > > - /* power up core phy and enable ref clock */ > - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > - IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); > - /* > - * the async reset input need ref clock to sync internally, > - * when the ref clock comes after reset, internal synced > - * reset time is too short, cannot meet the requirement. > - * add one ~10us delay here. > - */ > - udelay(10); > - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > - IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16); > + if (imx6_pcie->is_imx6sx) { > + ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi); > + if (ret) { > + dev_err(pp->dev, "unable to enable pcie_axi clock\n"); > + goto err_inbound_axi; > + } > + > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > + IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0); > + } else { > + /* power up core phy and enable ref clock */ > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > + IMX6Q_GPR1_PCIE_TEST_PD, 0); > + /* > + * the async reset input need ref clock to sync internally, > + * when the ref clock comes after reset, internal synced > + * reset time is too short , cannot meet the requirement. > + * add one ~10us delay here. > + */ > + udelay(10); > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, > + IMX6Q_GPR1_PCIE_REF_CLK_EN, > + IMX6Q_GPR1_PCIE_REF_CLK_EN); > + } Here again the diff is bigger than necessary because it re-indents the original code (and makes another unrelated "1 << 16" to IMX6Q_GPR1_PCIE_REF_CLK_EN change). I'll show a different proposal in my patch below. > /* allow the clocks to stabilize */ > usleep_range(200, 500); > @@ -292,8 +317,15 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) > msleep(100); > gpiod_set_value_cansleep(imx6_pcie->reset_gpio, 1); > } > + > + if (imx6_pcie->is_imx6sx) > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5, > + IMX6SX_GPR5_PCIE_BTNRST_RESET, 0); > + > return 0; > > +err_inbound_axi: > + clk_disable_unprepare(imx6_pcie->pcie); > err_pcie: > clk_disable_unprepare(imx6_pcie->pcie_bus); > err_pcie_bus: > @@ -307,6 +339,12 @@ static void imx6_pcie_init_phy(struct pcie_port *pp) > { > struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); > > + if (imx6_pcie->is_imx6sx) { > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > + IMX6SX_GPR12_PCIE_RX_EQ_MASK, > + IMX6SX_GPR12_PCIE_RX_EQ_2); I see that you added definitions for IMX6SX_GPR12_PCIE_RX_EQ_MASK and IMX6SX_GPR12_PCIE_RX_EQ_2 in the first patch of this series, but doing that separately creates a merge problem. I can't put this change in my tree by itself because it won't build. If Lee applied the first patch to a git branch, I guess I could pull that into my tree. But it would be far simpler to just include those new definitions in this patch. > + } > + > regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > IMX6Q_GPR12_PCIE_CTL_2, 0 << 10); > > @@ -571,6 +609,9 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) > pp = &imx6_pcie->pp; > pp->dev = &pdev->dev; > > + imx6_pcie->is_imx6sx = of_device_is_compatible(pp->dev->of_node, > + "fsl,imx6sx-pcie"); > + > /* Added for PCI abort handling */ > hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0, > "imprecise external abort"); > @@ -606,6 +647,16 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) > return PTR_ERR(imx6_pcie->pcie); > } > > + if (imx6_pcie->is_imx6sx) { > + imx6_pcie->pcie_inbound_axi = devm_clk_get(&pdev->dev, > + "pcie_inbound_axi"); > + if (IS_ERR(imx6_pcie->pcie_inbound_axi)) { > + dev_err(&pdev->dev, > + "pcie_incbound_axi clock missing or invalid\n"); > + return PTR_ERR(imx6_pcie->pcie_inbound_axi); > + } > + } > + > /* Grab GPR config register range */ > imx6_pcie->iomuxc_gpr = > syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr"); > @@ -632,6 +683,7 @@ static void imx6_pcie_shutdown(struct platform_device *pdev) > > static const struct of_device_id imx6_pcie_of_match[] = { > { .compatible = "fsl,imx6q-pcie", }, > + { .compatible = "fsl,imx6sx-pcie", }, > {}, > }; > MODULE_DEVICE_TABLE(of, imx6_pcie_of_match); The patches below are what I currently have in my tree, but they're not ready for v4.6 (yet). Note that the second one is very clearly imx6sx-only. It's obvious there are no tweaks to the existing imx6 code, which makes it easier to review, backport, bisect, revert, etc. Obviously, I can't apply these directly. First we have to: - Fix the LTSSM comment - Figure out how to get the IMX6SX_GPR12_PCIE_RX_EQ_MASK definitions commit 78abf60b815a8f28207d029d61f7809647faa43a Author: Bjorn Helgaas Date: Fri Mar 11 11:15:36 2016 -0600 PCI: imx6: Factor out ref clock enable Factor out ref clock enable to make it cleaner to add imx6sx support. No functional change intended. Signed-off-by: Bjorn Helgaas diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c index 8c9b389..ecc8537 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -269,6 +269,23 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp) return 0; } +static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie) +{ + /* power up core phy and enable ref clock */ + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, + IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); + /* + * the async reset input need ref clock to sync internally, + * when the ref clock comes after reset, internal synced + * reset time is too short, cannot meet the requirement. + * add one ~10us delay here. + */ + udelay(10); + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, + IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16); + return 0; +} + static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) { struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); @@ -292,18 +309,11 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) goto err_pcie; } - /* power up core phy and enable ref clock */ - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, - IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); - /* - * the async reset input need ref clock to sync internally, - * when the ref clock comes after reset, internal synced - * reset time is too short, cannot meet the requirement. - * add one ~10us delay here. - */ - udelay(10); - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, - IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16); + ret = imx6_pcie_enable_ref_clk(imx6_pcie); + if (ret) + dev_err(pp->dev, "unable to enable pcie ref clock\n"); + goto err_ref_clk; + } /* allow the clocks to stabilize */ usleep_range(200, 500); @@ -316,6 +326,8 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) } return 0; +err_ref_clk: + clk_disable_unprepare(imx6_pcie->pcie); err_pcie: clk_disable_unprepare(imx6_pcie->pcie_bus); err_pcie_bus: commit d061033570b7fd22a3ed8c029d4793e5df7324e1 Author: Christoph Fritz Date: Thu Mar 10 15:04:25 2016 -0600 PCI: imx6: Add initial imx6sx support Add initial PCIe support for the imx6 SoC derivate imx6sx. PCI MSI support is untested as the necessary suspend/resume quirk is not included in this patch. This patch is heavily based on patches by Richard Zhu. [bhelgaas: factor out refclk enable, fix adjacent typos in fsl,imx6q-pcie.txt] Signed-off-by: Christoph Fritz Acked-by: Richard Zhu Acked-by: Lucas Stach diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt index 3be80c6..0561e88 100644 --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt @@ -4,8 +4,8 @@ This PCIe host controller is based on the Synopsis Designware PCIe IP and thus inherits all the common properties defined in designware-pcie.txt. Required properties: -- compatible: "fsl,imx6q-pcie" -- reg: base addresse and length of the pcie controller +- compatible: "fsl,imx6q-pcie", "fsl,imx6sx-pcie" +- reg: base address and length of the PCIe controller - interrupts: A list of interrupt outputs of the controller. Must contain an entry for each entry in the interrupt-names property. - interrupt-names: Must include the following entries: @@ -20,6 +20,10 @@ Optional properties: - fsl,tx-swing-full: Gen2 TX SWING FULL value. Default: 127 - fsl,tx-swing-low: TX launch amplitude swing_low value. Default: 127 +Additional required properties for imx6sx-pcie: +- clock names: Must include the following additional entries: + - "pcie_inbound_axi" + Example: pcie at 0x01000000 { diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c index ecc8537..4d6af21 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -35,9 +35,11 @@ struct imx6_pcie { struct gpio_desc *reset_gpio; struct clk *pcie_bus; struct clk *pcie_phy; + struct clk *pcie_inbound_axi; struct clk *pcie; struct pcie_port pp; struct regmap *iomuxc_gpr; + bool is_imx6sx; void __iomem *mem_base; u32 tx_deemph_gen1; u32 tx_deemph_gen2_3p5db; @@ -236,13 +238,23 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp) struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); u32 val, gpr1, gpr12; + if (imx6_pcie->is_imx6sx) { + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, + IMX6SX_GPR12_PCIE_TEST_POWERDOWN, + IMX6SX_GPR12_PCIE_TEST_POWERDOWN); + /* Force PCIe PHY reset */ + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5, + IMX6SX_GPR5_PCIE_BTNRST_RESET, + IMX6SX_GPR5_PCIE_BTNRST_RESET); + return 0; + } + /* * If the bootloader already enabled the link we need some special * handling to get the core back into a state where it is safe to * touch it for configuration. As there is no dedicated reset signal - * wired up for MX6QDL, we need to manually force LTSSM into "detect" - * state before completely disabling LTSSM, which is a prerequisite - * for core configuration. + * to manually force LTSSM into "detect" state before completely + * disabling LTSSM, which is a prerequisite for core configuration. * * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong * indication that the bootloader activated the link. @@ -271,6 +283,18 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp) static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie) { + if (imx6_pcie->is_imx6sx) { + ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi); + if (ret) { + dev_err(pp->dev, "unable to enable pcie_axi clock\n"); + return ret; + } + + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, + IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0); + return 0; + } + /* power up core phy and enable ref clock */ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); @@ -324,6 +348,11 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) msleep(100); gpiod_set_value_cansleep(imx6_pcie->reset_gpio, 1); } + + if (imx6_pcie->is_imx6sx) + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5, + IMX6SX_GPR5_PCIE_BTNRST_RESET, 0); + return 0; err_ref_clk: @@ -341,6 +370,12 @@ static void imx6_pcie_init_phy(struct pcie_port *pp) { struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); + if (imx6_pcie->is_imx6sx) { + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, + IMX6SX_GPR12_PCIE_RX_EQ_MASK, + IMX6SX_GPR12_PCIE_RX_EQ_2); + } + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6Q_GPR12_PCIE_CTL_2, 0 << 10); @@ -565,6 +600,9 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) pp = &imx6_pcie->pp; pp->dev = &pdev->dev; + imx6_pcie->is_imx6sx = of_device_is_compatible(pp->dev->of_node, + "fsl,imx6sx-pcie"); + /* Added for PCI abort handling */ hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0, "imprecise external abort"); @@ -600,6 +638,16 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) return PTR_ERR(imx6_pcie->pcie); } + if (imx6_pcie->is_imx6sx) { + imx6_pcie->pcie_inbound_axi = devm_clk_get(&pdev->dev, + "pcie_inbound_axi"); + if (IS_ERR(imx6_pcie->pcie_inbound_axi)) { + dev_err(&pdev->dev, + "pcie_incbound_axi clock missing or invalid\n"); + return PTR_ERR(imx6_pcie->pcie_inbound_axi); + } + } + /* Grab GPR config register range */ imx6_pcie->iomuxc_gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr"); @@ -647,6 +695,7 @@ static void imx6_pcie_shutdown(struct platform_device *pdev) static const struct of_device_id imx6_pcie_of_match[] = { { .compatible = "fsl,imx6q-pcie", }, + { .compatible = "fsl,imx6sx-pcie", }, {}, }; MODULE_DEVICE_TABLE(of, imx6_pcie_of_match);