From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f67.google.com ([74.125.83.67]:34198 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754028AbdBTQJx (ORCPT ); Mon, 20 Feb 2017 11:09:53 -0500 From: Andrey Smirnov To: linux-pci@vger.kernel.org Cc: Andrey Smirnov , yurovsky@gmail.com, Lucas Stach , Bjorn Helgaas , Fabio Estevam , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [RESEND PATCH v5 4/4] PCI: imx6: Allow probe deferal by reset GPIO Date: Mon, 20 Feb 2017 08:09:00 -0800 Message-Id: <20170220160900.7014-5-andrew.smirnov@gmail.com> In-Reply-To: <20170220160900.7014-1-andrew.smirnov@gmail.com> References: <20170220160900.7014-1-andrew.smirnov@gmail.com> Sender: linux-pci-owner@vger.kernel.org List-ID: Some designs implement reset GPIO via a GPIO expander connected to a peripheral bus. One such example would be i.MX7 Sabre board where said GPIO is provided by SPI shift register connected to a bitbanged SPI bus. In order to support such designs allow reset GPIO request to defer probing of the driver. Cc: yurovsky@gmail.com Cc: Lucas Stach Cc: Bjorn Helgaas Cc: Fabio Estevam Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Andrey Smirnov --- drivers/pci/host/pci-imx6.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c index 071251f3..fe832e7f 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -638,8 +638,8 @@ static struct pcie_host_ops imx6_pcie_host_ops = { .host_init = imx6_pcie_host_init, }; -static int __init imx6_add_pcie_port(struct imx6_pcie *imx6_pcie, - struct platform_device *pdev) +static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie, + struct platform_device *pdev) { struct pcie_port *pp = &imx6_pcie->pp; struct device *dev = pp->dev; @@ -674,7 +674,7 @@ static int __init imx6_add_pcie_port(struct imx6_pcie *imx6_pcie, return 0; } -static int __init imx6_pcie_probe(struct platform_device *pdev) +static int imx6_pcie_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct imx6_pcie *imx6_pcie; @@ -693,10 +693,6 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) imx6_pcie->variant = (enum imx6_pcie_variants)of_device_get_match_data(dev); - /* Added for PCI abort handling */ - hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0, - "imprecise external abort"); - dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0); pp->dbi_base = devm_ioremap_resource(dev, dbi_base); if (IS_ERR(pp->dbi_base)) @@ -716,6 +712,8 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) dev_err(dev, "unable to get reset gpio\n"); return ret; } + } else if (imx6_pcie->reset_gpio == -EPROBE_DEFER) { + return imx6_pcie->reset_gpio; } /* Fetch clocks */ @@ -828,11 +826,22 @@ static struct platform_driver imx6_pcie_driver = { .name = "imx6q-pcie", .of_match_table = imx6_pcie_of_match, }, + .probe = imx6_pcie_probe, .shutdown = imx6_pcie_shutdown, }; static int __init imx6_pcie_init(void) { - return platform_driver_probe(&imx6_pcie_driver, imx6_pcie_probe); + /* + * Since probe() can be deferred we need to make sure that + * hook_fault_code is not called after __init memory is freed + * by kernel and since imx6q_pcie_abort_handler() is a no-op + * we can install the handler here without risking it + * accessing some unitialized driver state + */ + hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0, + "imprecise external abort"); + + return platform_driver_register(&imx6_pcie_driver); } device_initcall(imx6_pcie_init); -- 2.9.3