On Wed, Nov 7, 2018 at 5:57 AM Leonard Crestez <leonard.crestez@xxxxxxx> wrote: > > Enable PCI suspend/resume support on imx6sx socs. This is similar to > imx7d with a few differences: > > * The PM_Turn_Off bit is exposed through an IOMUX GPR, like all other > pcie control bits on 6sx. > * The pcie_inbound_axi clk needs to be turned off in suspend. On resume > it is restored via resume -> deassert_core_reset -> enable_ref_clk. > > Most of the resume logic is shared with the initial reset after probe. > > Signed-off-by: Leonard Crestez <leonard.crestez@xxxxxxx> > > --- > Changes since v1: > * Use a switch statement in imx6_pcie_pm_turnoff. The DT-based turnoff > path is still an if statement. > * Did not split imx6_pcie_clk_disable or call it from other paths, this > would bring complications and is somewhat unrelated. > * See v1 comments: https://lore.kernel.org/patchwork/patch/996806/ > > drivers/pci/controller/dwc/pci-imx6.c | 44 ++++++++++++++++++--- > include/linux/mfd/syscon/imx6q-iomuxc-gpr.h | 1 + > 2 files changed, 40 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index 2cbef2d7c207..54625569d0bc 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -771,41 +771,75 @@ static void imx6_pcie_ltssm_disable(struct device *dev) > } > } > > static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie) > { > - reset_control_assert(imx6_pcie->turnoff_reset); > - reset_control_deassert(imx6_pcie->turnoff_reset); > + struct device *dev = imx6_pcie->pci->dev; > + > + /* Some variants have a turnoff reset in DT */ > + if (imx6_pcie->turnoff_reset) { > + reset_control_assert(imx6_pcie->turnoff_reset); > + reset_control_deassert(imx6_pcie->turnoff_reset); > + goto pm_turnoff_sleep; > + } > + > + /* Others poke directly at IOMUXC registers */ > + switch (imx6_pcie->variant) { > + case IMX6SX: > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > + IMX6SX_GPR12_PCIE_PM_TURN_OFF, > + IMX6SX_GPR12_PCIE_PM_TURN_OFF); > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > + IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0); > + break; > + default: > + dev_err(dev, "PME_Turn_Off not implemented\n"); > + return; Purely optionally, if you feel like avoiding goto you can change this to: default: if (!imx6_pcie->turnoff_reset) { dev_err(dev, "PME_Turn_Off not implemented\n"); return; } reset_control_assert(imx6_pcie->turnoff_reset); reset_control_deassert(imx6_pcie->turnoff_reset); break; but that's up to you. FWIW, patch looks reasonable: Reviewed-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx> > + } > > /* > * Components with an upstream port must respond to > * PME_Turn_Off with PME_TO_Ack but we can't check. > * > * The standard recommends a 1-10ms timeout after which to > * proceed anyway as if acks were received. > */ > +pm_turnoff_sleep: > usleep_range(1000, 10000); > } > > 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) { > + switch (imx6_pcie->variant) { > + case IMX6SX: > + clk_disable_unprepare(imx6_pcie->pcie_inbound_axi); > + break; > + case IMX7D: > regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, > IMX7D_GPR12_PCIE_PHY_REFCLK_SEL); > + break; > + default: > + break; > } > } > > +static inline bool imx6_pcie_supports_suspend(struct imx6_pcie *imx6_pcie) > +{ > + return (imx6_pcie->variant == IMX7D || > + imx6_pcie->variant == IMX6SX); > +} > + > static int imx6_pcie_suspend_noirq(struct device *dev) > { > struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev); > > - if (imx6_pcie->variant != IMX7D) > + if (!imx6_pcie_supports_suspend(imx6_pcie)) > return 0; > > imx6_pcie_pm_turnoff(imx6_pcie); > imx6_pcie_clk_disable(imx6_pcie); > imx6_pcie_ltssm_disable(dev); > @@ -817,11 +851,11 @@ 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) > + if (!imx6_pcie_supports_suspend(imx6_pcie)) > return 0; > > imx6_pcie_assert_core_reset(imx6_pcie); > imx6_pcie_init_phy(imx6_pcie); > imx6_pcie_deassert_core_reset(imx6_pcie); > diff --git a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h > index 6c1ad160ed87..c1b25f5e386d 100644 > --- a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h > +++ b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h > @@ -438,10 +438,11 @@ > #define IMX6SX_GPR5_DISP_MUX_DCIC1_LCDIF1 (0x0 << 1) > #define IMX6SX_GPR5_DISP_MUX_DCIC1_LVDS (0x1 << 1) > #define IMX6SX_GPR5_DISP_MUX_DCIC1_MASK (0x1 << 1) > > #define IMX6SX_GPR12_PCIE_TEST_POWERDOWN BIT(30) > +#define IMX6SX_GPR12_PCIE_PM_TURN_OFF BIT(16) > #define IMX6SX_GPR12_PCIE_RX_EQ_MASK (0x7 << 0) > #define IMX6SX_GPR12_PCIE_RX_EQ_2 (0x2 << 0) > > /* For imx6ul iomux gpr register field define */ > #define IMX6UL_GPR1_ENET1_CLK_DIR (0x1 << 17) > -- > 2.17.1 >
