[PATCH] PCI: imx6: properly shut down core when leaving barebox

[PATCH] PCI: imx6: properly shut down core when leaving barebox

[Lucas Stach]

As the i.MX6 PCIe core doesn't have a software reachable reset
wired up, it's hard for any driver to get the core into a known
good state.

To make it easier for whatever software follows barebox, bring
back the core into a safe state before leaving barebox.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
This patch is on top of Andrey Smirnovs changes to the
imx6 pcie driver.
---
 drivers/pci/pci-imx6.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/pci/pci-imx6.c b/drivers/pci/pci-imx6.c
index 3a3edd8e218e..d32bd2b4cefa 100644
--- a/drivers/pci/pci-imx6.c
+++ b/drivers/pci/pci-imx6.c
@@ -608,9 +608,35 @@ static int __init imx6_pcie_probe(struct device_d *dev)
 	if (ret < 0)
 		return ret;
 
+	dev->priv = imx6_pcie;
+
 	return 0;
 }
 
+static void imx6_pcie_remove(struct device_d *dev)
+{
+	struct imx6_pcie *imx6_pcie = dev->priv;
+	u32 val;
+
+	val = readl(imx6_pcie->pp.dbi_base + PCIE_PL_PFLR);
+	val &= ~PCIE_PL_PFLR_LINK_STATE_MASK;
+	val |= PCIE_PL_PFLR_FORCE_LINK;
+	data_abort_mask();
+	writel(val, imx6_pcie->pp.dbi_base + PCIE_PL_PFLR);
+	data_abort_unmask();
+
+	val = readl(imx6_pcie->iomuxc_gpr + IOMUXC_GPR12);
+	val &= ~IMX6Q_GPR12_PCIE_CTL_2;
+	writel(val, imx6_pcie->iomuxc_gpr + IOMUXC_GPR12);
+
+	val = readl(imx6_pcie->iomuxc_gpr + IOMUXC_GPR1);
+	val |= IMX6Q_GPR1_PCIE_TEST_PD;
+	writel(val, imx6_pcie->iomuxc_gpr + IOMUXC_GPR1);
+
+	val &= ~IMX6Q_GPR1_PCIE_REF_CLK_EN;
+	writel(val, imx6_pcie->iomuxc_gpr + IOMUXC_GPR1);
+}
+
 static struct of_device_id imx6_pcie_of_match[] = {
 	{ .compatible = "fsl,imx6q-pcie", },
 	{},
@@ -620,6 +646,7 @@ static struct driver_d imx6_pcie_driver = {
 	.name = "imx6-pcie",
 	.of_compatible = DRV_OF_COMPAT(imx6_pcie_of_match),
 	.probe = imx6_pcie_probe,
+	.remove = imx6_pcie_remove,
 };
 device_platform_driver(imx6_pcie_driver);
 
-- 
2.6.4


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Re: [PATCH] PCI: imx6: properly shut down core when leaving barebox

[Sascha Hauer]

On Thu, Jan 07, 2016 at 10:40:23AM +0100, Lucas Stach wrote:
> As the i.MX6 PCIe core doesn't have a software reachable reset
> wired up, it's hard for any driver to get the core into a known
> good state.
> 
> To make it easier for whatever software follows barebox, bring
> back the core into a safe state before leaving barebox.
> 
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
> This patch is on top of Andrey Smirnovs changes to the
> imx6 pcie driver.
> ---
>  drivers/pci/pci-imx6.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)

Applied, thanks

Sascha

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