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PCI: imx6: Factor out ref clock enable

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Factor out ref clock enable to make it cleaner to add imx6sx support.  No
functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Christoph Fritz <chf.fritz@googlemail.com>
This commit is contained in:
Bjorn Helgaas 2016-03-14 00:30:55 +01:00
parent b2d7a9cd3f
commit 4d1821e729
1 changed files with 24 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
drivers/pci/host/pci-imx6.c
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@ -269,6 +269,23 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp)
return 0; return 0;
} }
static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
{
/* power up core phy and enable ref clock */
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
/*
* the async reset input need ref clock to sync internally,
* when the ref clock comes after reset, internal synced
* reset time is too short, cannot meet the requirement.
* add one ~10us delay here.
*/
udelay(10);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
return 0;
}
static int imx6_pcie_deassert_core_reset(struct pcie_port *pp) static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
{ {
struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
@ -292,18 +309,11 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
goto err_pcie; goto err_pcie;
} }
/* power up core phy and enable ref clock */ ret = imx6_pcie_enable_ref_clk(imx6_pcie);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, if (ret) {
IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); dev_err(pp->dev, "unable to enable pcie ref clock\n");
/* goto err_ref_clk;
* the async reset input need ref clock to sync internally, }
* when the ref clock comes after reset, internal synced
* reset time is too short, cannot meet the requirement.
* add one ~10us delay here.
*/
udelay(10);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
/* allow the clocks to stabilize */ /* allow the clocks to stabilize */
usleep_range(200, 500); usleep_range(200, 500);
@ -316,6 +326,8 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
} }
return 0; return 0;
err_ref_clk:
clk_disable_unprepare(imx6_pcie->pcie);
err_pcie: err_pcie:
clk_disable_unprepare(imx6_pcie->pcie_bus); clk_disable_unprepare(imx6_pcie->pcie_bus);
err_pcie_bus: err_pcie_bus: