Am Dienstag, den 24.07.2018, 19:14 +0300 schrieb Leonard Crestez: > On imx7d the pcie-phy power domain is turned off in suspend and this can > make the system hang after resume when attempting any read from PCI. > > Fix this by adding minimal suspend/resume code from the nxp internal > tree. This will prepare for powering down on suspend and reset the block > on resume. > > Code is only for imx7d but a very similar sequence can be used for > other socs. > > > The original author is mostly Richard Zhu <[email protected]>, this > patch adjusts the code to the upstream imx7d implemention using reset > controls and power domains. > > Signed-off-by: Leonard Crestez <[email protected]>
Reviewed-by: Lucas Stach <[email protected]> > --- > drivers/pci/controller/dwc/pci-imx6.c | 97 +++++++++++++++++++++++++-- > 1 file changed, 92 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c > b/drivers/pci/controller/dwc/pci-imx6.c > index 4a9a673b4777..65b6d1015723 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -540,10 +540,28 @@ static int imx6_pcie_wait_for_speed_change(struct > imx6_pcie *imx6_pcie) > > > dev_err(dev, "Speed change timeout\n"); > > return -EINVAL; > } > > +static void imx6_pcie_ltssm_enable(struct device *dev) > +{ > > + struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev); > + > > + switch (imx6_pcie->variant) { > > + case IMX6Q: > > + case IMX6SX: > > + case IMX6QP: > > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > > + IMX6Q_GPR12_PCIE_CTL_2, > > + IMX6Q_GPR12_PCIE_CTL_2); > > + break; > > + case IMX7D: > > + reset_control_deassert(imx6_pcie->apps_reset); > > + break; > > + } > +} > + > static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie) > { > > struct dw_pcie *pci = imx6_pcie->pci; > > struct device *dev = pci->dev; > > u32 tmp; > @@ -558,15 +576,11 @@ static int imx6_pcie_establish_link(struct imx6_pcie > *imx6_pcie) > > tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK; > > tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1; > > dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp); > > > /* Start LTSSM. */ > > - if (imx6_pcie->variant == IMX7D) > > - reset_control_deassert(imx6_pcie->apps_reset); > > - else > > - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > > - IMX6Q_GPR12_PCIE_CTL_2, 1 << 10); > > + imx6_pcie_ltssm_enable(dev); > > > ret = imx6_pcie_wait_for_link(imx6_pcie); > > if (ret) > > goto err_reset_phy; > > @@ -680,10 +694,82 @@ static int imx6_add_pcie_port(struct imx6_pcie > *imx6_pcie, > > static const struct dw_pcie_ops dw_pcie_ops = { > > .link_up = imx6_pcie_link_up, > }; > > +#ifdef CONFIG_PM_SLEEP > +static void imx6_pcie_ltssm_disable(struct device *dev) > +{ > > + struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev); > + > > + switch (imx6_pcie->variant) { > > + case IMX6SX: > > + case IMX6QP: > > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > > + IMX6Q_GPR12_PCIE_CTL_2, 0); > > + break; > > + case IMX7D: > > + reset_control_assert(imx6_pcie->apps_reset); > > + break; > > + default: > > + dev_err(dev, "ltssm_disable not supported\n"); > > + } > +} > + > +static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie) > +{ > > + clk_disable_unprepare(imx6_pcie->pcie); > > + clk_disable_unprepare(imx6_pcie->pcie_phy); > > + clk_disable_unprepare(imx6_pcie->pcie_bus); > + > > + if (imx6_pcie->variant == IMX7D) { > > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > > + IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, > > + IMX7D_GPR12_PCIE_PHY_REFCLK_SEL); > > + } > +} > + > +static int imx6_pcie_suspend_noirq(struct device *dev) > +{ > > + struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev); > + > > + if (imx6_pcie->variant != IMX7D) > > + return 0; > + > > + imx6_pcie_clk_disable(imx6_pcie); > > + imx6_pcie_ltssm_disable(dev); > + > > + return 0; > +} > + > +static int imx6_pcie_resume_noirq(struct device *dev) > +{ > > + int ret; > > + struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev); > > + struct pcie_port *pp = &imx6_pcie->pci->pp; > + > > + if (imx6_pcie->variant != IMX7D) > > + return 0; > + > > + imx6_pcie_assert_core_reset(imx6_pcie); > > + imx6_pcie_init_phy(imx6_pcie); > > + imx6_pcie_deassert_core_reset(imx6_pcie); > > + dw_pcie_setup_rc(pp); > + > > + ret = imx6_pcie_establish_link(imx6_pcie); > > + if (ret < 0) > > + dev_info(dev, "pcie link is down after resume.\n"); > + > > + return 0; > +} > +#endif > + > +static const struct dev_pm_ops imx6_pcie_pm_ops = { > > + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx6_pcie_suspend_noirq, > > + imx6_pcie_resume_noirq) > +}; > + > static int imx6_pcie_probe(struct platform_device *pdev) > { > > struct device *dev = &pdev->dev; > > struct dw_pcie *pci; > > struct imx6_pcie *imx6_pcie; > @@ -846,10 +932,11 @@ static const struct of_device_id imx6_pcie_of_match[] = > { > static struct platform_driver imx6_pcie_driver = { > > .driver = { > > > .name = "imx6q-pcie", > > .of_match_table = imx6_pcie_of_match, > > .suppress_bind_attrs = true, > > + .pm = &imx6_pcie_pm_ops, > > }, > > .probe = imx6_pcie_probe, > > .shutdown = imx6_pcie_shutdown, > }; >
