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authorAndrey Smirnov <andrew.smirnov@gmail.com>2016-05-02 21:09:10 +0200
committerBjorn Helgaas <bhelgaas@google.com>2016-05-02 21:33:17 +0200
commit4d31c6109a24892df461b6a98842935e80159a5e (patch)
treedf1343bf8354c06ff5a5e96d27ec0093a2959c68 /drivers/pci
parentPCI: imx6: Use enum instead of bool for variant indicator (diff)
downloadlinux-4d31c6109a24892df461b6a98842935e80159a5e.tar.xz
linux-4d31c6109a24892df461b6a98842935e80159a5e.zip
PCI: imx6: Implement reset sequence for i.MX6+
I.MX6+ has a dedicated bit for resetting PCIe core, which should be used instead of a regular reset sequence since using the latter will hang the SoC. This commit is based on c34068d48273e24d392d9a49a38be807954420ed from http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git Tested-by: Gary Bisson <gary.bisson@boundarydevices.com> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/host/pci-imx6.c23
1 files changed, 21 insertions, 2 deletions
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 6b5d8c2fe2f2..b741a36a67f3 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -34,7 +34,8 @@
enum imx6_pcie_variants {
IMX6Q,
- IMX6SX
+ IMX6SX,
+ IMX6QP,
};
struct imx6_pcie {
@@ -256,6 +257,11 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp)
IMX6SX_GPR5_PCIE_BTNRST_RESET,
IMX6SX_GPR5_PCIE_BTNRST_RESET);
break;
+ case IMX6QP:
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+ IMX6Q_GPR1_PCIE_SW_RST,
+ IMX6Q_GPR1_PCIE_SW_RST);
+ break;
case IMX6Q:
/*
* If the bootloader already enabled the link we need some
@@ -310,6 +316,7 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0);
break;
+ case IMX6QP: /* FALLTHROUGH */
case IMX6Q:
/* power up core phy and enable ref clock */
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
@@ -370,9 +377,20 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
!imx6_pcie->gpio_active_high);
}
- if (imx6_pcie->variant == IMX6SX)
+ switch (imx6_pcie->variant) {
+ case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
+ break;
+ case IMX6QP:
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+ IMX6Q_GPR1_PCIE_SW_RST, 0);
+
+ usleep_range(200, 500);
+ break;
+ case IMX6Q: /* Nothing to do */
+ break;
+ }
return 0;
@@ -718,6 +736,7 @@ static void imx6_pcie_shutdown(struct platform_device *pdev)
static const struct of_device_id imx6_pcie_of_match[] = {
{ .compatible = "fsl,imx6q-pcie", .data = (void *)IMX6Q, },
{ .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, },
+ { .compatible = "fsl,imx6qp-pcie", .data = (void *)IMX6QP, },
{},
};
MODULE_DEVICE_TABLE(of, imx6_pcie_of_match);