diff options
Diffstat (limited to 'drivers/pci/pcie_imx.c')
| -rw-r--r-- | drivers/pci/pcie_imx.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/pci/pcie_imx.c b/drivers/pci/pcie_imx.c index 732d59d..eab0a2b 100644 --- a/drivers/pci/pcie_imx.c +++ b/drivers/pci/pcie_imx.c @@ -42,6 +42,9 @@ /* 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_LINK_UP (1 << 4) @@ -445,6 +448,36 @@ static int imx6_pcie_assert_core_reset(void) /* Power up PCIe PHY */ setbits_le32(&gpc_regs->cntr, PCIE_PHY_PUP_REQ); #else + /* + * 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. + */ + if (is_mx6dq()) { + u32 val, gpr1, gpr12; + + gpr1 = readl(&iomuxc_regs->gpr[1]); + gpr12 = readl(&iomuxc_regs->gpr[12]); + if ((gpr1 & IOMUXC_GPR1_PCIE_REF_CLK_EN) && + (gpr12 & IOMUXC_GPR12_PCIE_CTL_2)) { + val = readl(MX6_DBI_ADDR + PCIE_PL_PFLR); + val &= ~PCIE_PL_PFLR_LINK_STATE_MASK; + val |= PCIE_PL_PFLR_FORCE_LINK; + + imx_pcie_fix_dabt_handler(true); + writel(val, MX6_DBI_ADDR + PCIE_PL_PFLR); + imx_pcie_fix_dabt_handler(false); + + gpr12 &= ~IOMUXC_GPR12_PCIE_CTL_2; + writel(val, &iomuxc_regs->gpr[12]); + } + } setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_TEST_POWERDOWN); clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_REF_SSP_EN); #endif @@ -652,6 +685,11 @@ void imx_pcie_init(void) } } +void imx_pcie_remove(void) +{ + imx6_pcie_assert_core_reset(); +} + /* Probe function. */ void pci_init_board(void) { |