diff options
| -rw-r--r-- | drivers/pci/host/pci-imx6.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c index a568efaa331c..35fc73a8d0b3 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -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 */ |