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-rw-r--r--arch/arm/imx-common/cpu.c3
-rw-r--r--drivers/pci/pcie_imx.c38
-rw-r--r--include/pci.h4
3 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm/imx-common/cpu.c b/arch/arm/imx-common/cpu.c
index 40fe813d290..74bdd24ed1e 100644
--- a/arch/arm/imx-common/cpu.c
+++ b/arch/arm/imx-common/cpu.c
@@ -275,6 +275,9 @@ u32 get_ahb_clk(void)
void arch_preboot_os(void)
{
+#if defined(CONFIG_PCIE_IMX)
+ imx_pcie_remove();
+#endif
#if defined(CONFIG_CMD_SATA)
sata_stop();
#if defined(CONFIG_MX6)
diff --git a/drivers/pci/pcie_imx.c b/drivers/pci/pcie_imx.c
index 732d59d7110..eab0a2b602f 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)
{
diff --git a/include/pci.h b/include/pci.h
index d3c955eb801..c8ef997d0de 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -754,6 +754,10 @@ int pci_last_busno(void);
extern void pci_mpc85xx_init (struct pci_controller *hose);
#endif
+#ifdef CONFIG_PCIE_IMX
+extern void imx_pcie_remove(void);
+#endif
+
#if !defined(CONFIG_DM_PCI) || defined(CONFIG_DM_PCI_COMPAT)
/**
* pci_write_bar32() - Write the address of a BAR including control bits