PCI driver currently hangs on mx6qp.
Toggle the reset bit with the appropriate timings to fix the issue.
Based on the FSL kernel driver implementation.
Signed-off-by: Fabio Estevam fabio.estevam@freescale.com --- arch/arm/include/asm/arch-mx6/iomux.h | 2 ++ drivers/pci/pcie_imx.c | 14 ++++++++++++++ 2 files changed, 16 insertions(+)
diff --git a/arch/arm/include/asm/arch-mx6/iomux.h b/arch/arm/include/asm/arch-mx6/iomux.h index 9b3a91f..e3ef59f 100644 --- a/arch/arm/include/asm/arch-mx6/iomux.h +++ b/arch/arm/include/asm/arch-mx6/iomux.h @@ -18,6 +18,8 @@ #define IOMUXC_GPR1_REF_SSP_EN (1 << 16) #define IOMUXC_GPR1_TEST_POWERDOWN (1 << 18)
+#define IOMUXC_GPR1_PCIE_SW_RST (1 << 29) + /* * IOMUXC_GPR5 bit fields */ diff --git a/drivers/pci/pcie_imx.c b/drivers/pci/pcie_imx.c index 1568f20..ddfe389 100644 --- a/drivers/pci/pcie_imx.c +++ b/drivers/pci/pcie_imx.c @@ -19,6 +19,7 @@ #include <asm/io.h> #include <linux/sizes.h> #include <errno.h> +#include <asm/arch/sys_proto.h>
#define PCI_ACCESS_READ 0 #define PCI_ACCESS_WRITE 1 @@ -430,6 +431,10 @@ static int imx_pcie_write_config(struct pci_controller *hose, pci_dev_t d, static int imx6_pcie_assert_core_reset(void) { struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR; + + if (is_mx6dqp()) + setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_PCIE_SW_RST); + #if defined(CONFIG_MX6SX) struct gpc *gpc_regs = (struct gpc *)GPC_BASE_ADDR;
@@ -542,6 +547,15 @@ static int imx6_pcie_deassert_core_reset(void) */ mdelay(50);
+ if (is_mx6dqp()) { + clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_PCIE_SW_RST); + /* + * some delay is required by 6qp, after the SW_RST is + * cleared and before accessing the cfg register. + */ + udelay(200); + } + #if defined(CONFIG_MX6SX) /* SSP_EN is not used on MX6SX anymore */ clrbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_TEST_POWERDOWN);