From: Andrey Smirnov <andrew.smirnov@gmail.com>
To: linux-pci@vger.kernel.org
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>,
linux-kernel@vger.kernel.org,
Fabio Estevam <fabio.estevam@nxp.com>,
Bjorn Helgaas <bhelgaas@google.com>,
yurovsky@gmail.com, linux-arm-kernel@lists.infradead.org,
Lucas Stach <l.stach@pengutronix.de>
Subject: [PATCH v5 4/4] PCI: imx6: Allow probe deferal by reset GPIO
Date: Mon, 20 Feb 2017 07:30:25 -0800 [thread overview]
Message-ID: <20170220153025.32096-5-andrew.smirnov@gmail.com> (raw)
In-Reply-To: <20170220153025.32096-1-andrew.smirnov@gmail.com>
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 <l.stach@pengutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
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
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next prev parent reply other threads:[~2017-02-20 15:30 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-20 15:30 [PATCH v5 0/4] i.MX7 PCI support Andrey Smirnov
2017-02-20 15:30 ` [PATCH v5 1/4] PCI: imx6: Add code to support i.MX7D Andrey Smirnov
2017-03-14 14:43 ` Lee Jones
2017-02-20 15:30 ` [PATCH v5 2/4] PCI: imx6: Do not wait for speed change on i.MX7 Andrey Smirnov
2017-02-20 15:30 ` [PATCH v5 3/4] PCI: imx6: Do not switch speed if Gen2 is disabled Andrey Smirnov
2017-02-20 15:30 ` Andrey Smirnov [this message]
2017-02-20 15:47 ` [PATCH v5 0/4] i.MX7 PCI support Andrey Smirnov
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