diff options
author | Richard Zhu <Richard.Zhu@freescale.com> | 2015-02-05 16:13:07 +0800 |
---|---|---|
committer | Richard Zhu <Richard.Zhu@freescale.com> | 2015-02-11 15:19:48 +0800 |
commit | 334af1b0fdb473a36a42bd0bb638ef2b7e26033f (patch) | |
tree | d47dd323763da586de306efdc96ee74a271684da | |
parent | 15290d39e1ba88d9c27c69f4691a14681a5cf42d (diff) |
MLK-10203-1 pci: imx: enable imx6qdl pcie support
enable imx6qdl pcie on imx_3.14 kernel
and add the pcie pm workaround for imx6qdl.
------
L2 can exit by 'reset' or Inband beacon (from remote EP)
toggling phy_powerdown has same effect as 'inband beacon'
So, toggle bit18 of GPR1, used as a workaround of errata
"PCIe PCIe does not support L2 Power Down"
WARNING: This is not official workaround for ERR005723.
Fortunately, we don't encounter issue with this workaround.
User should take own risk to use it.
Signed-off-by: Richard Zhu <Richard.Zhu@freescale.com>
(cherry picked from commit 4cdd4fb7fb3b3e746b66838f4cdd24fccd67c78d)
-rw-r--r-- | drivers/pci/host/pci-imx6.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c index c120ee1052b2..1b53010ea49c 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -45,9 +45,11 @@ static u32 ddr_test_region = 0, test_region_size = SZ_2M; struct imx6_pcie { int reset_gpio; + int power_on_gpio; struct clk *pcie_bus; struct clk *pcie_phy; struct clk *pcie_inbound_axi; + struct clk *ref_100m; struct clk *pcie; struct pcie_port pp; struct regmap *iomuxc_gpr; @@ -292,6 +294,9 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); int ret; + if (gpio_is_valid(imx6_pcie->power_on_gpio)) + gpio_set_value(imx6_pcie->power_on_gpio, 1); + request_bus_freq(BUS_FREQ_HIGH); ret = clk_prepare_enable(imx6_pcie->pcie_phy); if (ret) { @@ -327,6 +332,13 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) /* power up core phy and enable ref clock */ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_TEST_PD, 0); + + /* sata_ref is not used by pcie on imx6sx */ + ret = clk_prepare_enable(imx6_pcie->ref_100m); + if (ret) { + dev_err(pp->dev, "unable to enable ref_100m\n"); + goto err_inbound_axi; + } /* * the async reset input need ref clock to sync internally, * when the ref clock comes after reset, internal synced @@ -525,6 +537,9 @@ out: * Power down PCIe PHY. */ regulator_disable(imx6_pcie->pcie_phy_regulator); + } else { + clk_disable_unprepare(imx6_pcie->ref_100m); + release_bus_freq(BUS_FREQ_HIGH); } } else { tmp = readl(pp->dbi_base + 0x80); @@ -901,6 +916,16 @@ static int pci_imx_suspend_noirq(struct device *dev) clk_disable_unprepare(imx6_pcie->pcie_inbound_axi); release_bus_freq(BUS_FREQ_HIGH); } + } else { + /* + * L2 can exit by 'reset' or Inband beacon (from remote EP) + * toggling phy_powerdown has same effect as 'inband beacon' + * So, toggle bit18 of GPR1, used as a workaround of errata + * "PCIe PCIe does not support L2 Power Down" + */ + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, + IMX6Q_GPR1_PCIE_TEST_PD, + IMX6Q_GPR1_PCIE_TEST_PD); } return 0; @@ -956,6 +981,15 @@ static int pci_imx_resume_noirq(struct device *dev) if (IS_ENABLED(CONFIG_PCI_MSI)) dw_pcie_msi_cfg_restore(pp); } + } else { + /* + * L2 can exit by 'reset' or Inband beacon (from remote EP) + * toggling phy_powerdown has same effect as 'inband beacon' + * So, toggle bit18 of GPR1, used as a workaround of errata + * "PCIe PCIe does not support L2 Power Down" + */ + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, + IMX6Q_GPR1_PCIE_TEST_PD, 0); } return 0; @@ -1013,6 +1047,18 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) } } + imx6_pcie->power_on_gpio = of_get_named_gpio(np, "power-on-gpio", 0); + if (gpio_is_valid(imx6_pcie->power_on_gpio)) { + ret = devm_gpio_request_one(&pdev->dev, + imx6_pcie->power_on_gpio, + GPIOF_OUT_INIT_LOW, + "PCIe power enable"); + if (ret) { + dev_err(&pdev->dev, "unable to get power-on gpio\n"); + return ret; + } + } + /* Fetch clocks */ imx6_pcie->pcie_phy = devm_clk_get(&pdev->dev, "pcie_phy"); if (IS_ERR(imx6_pcie->pcie_phy)) { @@ -1051,6 +1097,14 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) syscon_regmap_lookup_by_compatible ("fsl,imx6sx-iomuxc-gpr"); } else { + /* sata_ref is not used by pcie on imx6sx */ + imx6_pcie->ref_100m = devm_clk_get(&pdev->dev, "ref_100m"); + if (IS_ERR(imx6_pcie->ref_100m)) { + dev_err(&pdev->dev, + "ref_100m clock source missing or invalid\n"); + return PTR_ERR(imx6_pcie->ref_100m); + } + imx6_pcie->iomuxc_gpr = syscon_regmap_lookup_by_compatible ("fsl,imx6q-iomuxc-gpr"); |