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Commit fd7155fc authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

Merge branch 'pci/host-imx6' into for-linus 

* pci/host-imx6:
  PCI: imx6: Put LTSSM in "Detect" state before disabling it
  MAINTAINERS: Add Lucas Stach as co-maintainer for i.MX6 PCI driver
parents 52addcf9 3e3e406e

MAINTAINERS

+1 −1
Original line number Diff line number Diff line
@@ -6870,7 +6870,7 @@ F: arch/x86/kernel/quirks.c 


PCI DRIVER FOR IMX6

M:	Richard Zhu <r65037@freescale.com>

M:	Shawn Guo <shawn.guo@freescale.com>

M:	Lucas Stach <l.stach@pengutronix.de>

L:	linux-pci@vger.kernel.org

L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)

S:	Maintained

drivers/pci/host/pci-imx6.c

+38 −0
Original line number Diff line number Diff line
@@ -49,6 +49,9 @@ struct imx6_pcie { 


/* PCIe Port Logic registers (memory-mapped) */

#define PL_OFFSET 0x700

#define PCIE_PL_PFLR (PL_OFFSET + 0x08)

#define PCIE_PL_PFLR_LINK_STATE_MASK		(0x3f << 16)

#define PCIE_PL_PFLR_FORCE_LINK			(1 << 15)

#define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)

#define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)

#define PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING	(1 << 29)
@@ -214,6 +217,32 @@ static int imx6q_pcie_abort_handler(unsigned long addr, 
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);



		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,

				IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);

	}



	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,

			IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
@@ -589,6 +618,14 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) 
	return 0;

}



static void imx6_pcie_shutdown(struct platform_device *pdev)

{

	struct imx6_pcie *imx6_pcie = platform_get_drvdata(pdev);



	/* bring down link, so bootloader gets clean state in case of reboot */

	imx6_pcie_assert_core_reset(&imx6_pcie->pp);

}



static const struct of_device_id imx6_pcie_of_match[] = {

	{ .compatible = "fsl,imx6q-pcie", },

	{},
@@ -601,6 +638,7 @@ static struct platform_driver imx6_pcie_driver = { 
		.owner	= THIS_MODULE,

		.of_match_table = imx6_pcie_of_match,

	},

	.shutdown = imx6_pcie_shutdown,

};



/* Freescale PCIe driver does not allow module unload */