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

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* 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
This commit is contained in:
Bjorn Helgaas
2014-09-04 14:20:25 -06:00
parent 52addcf9d6 3e3e406e38
commit fd7155fc9f
2 changed files with 39 additions and 1 deletions
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2
MAINTAINERS
View File

@@ -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

38
drivers/pci/host/pci-imx6.c
View File

@@ -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 */