Hi Leonard, On Wed, 2018-10-31 at 11:02 +0000, Leonard Crestez wrote: > On 10/8/2018 8:38 PM, Leonard Crestez 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.cres...@nxp.com> > > This is a gentle reminder that this patch was posted ~3 weeks ago and > there is yet no reply. It's a mostly straight-forward extension of imx7d > pci suspend/resume support to a different SOC. > > Lucas/Philipp: can you please take a brief look?
This is a bit out of my wheelhouse, but I'll try my best. > > --- > > drivers/pci/controller/dwc/pci-imx6.c | 40 ++++++++++++++++++--- > > include/linux/mfd/syscon/imx6q-iomuxc-gpr.h | 1 + > > 2 files changed, 36 insertions(+), 5 deletions(-) > > > > Patch is again linux-next, meant to apply here: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/log/?h=pci/dwc > > > > This is quite an old patch, mostly did it to prove that imx7d suspend > > support is indeed generic. > > > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c > > b/drivers/pci/controller/dwc/pci-imx6.c > > index 2cbef2d7c207..6171171db1fc 100644 > > --- a/drivers/pci/controller/dwc/pci-imx6.c > > +++ b/drivers/pci/controller/dwc/pci-imx6.c > > @@ -771,12 +771,29 @@ 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 while > > + * others poke at iomuxc registers. > > + */ > > + if (imx6_pcie->turnoff_reset) { > > + reset_control_assert(imx6_pcie->turnoff_reset); > > + reset_control_deassert(imx6_pcie->turnoff_reset); > > + } else if (imx6_pcie->variant == 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); > > + } else { > > + dev_err(dev, "PME_Turn_Off not implemented\n"); > > + return; > > + } I'd use switch(imx6_pcie->variant) for consistency with the other places where different variants need to be handled separately. > > > > /* > > * Components with an upstream port must respond to > > * PME_Turn_Off with PME_TO_Ack but we can't check. > > * > > @@ -790,22 +807,35 @@ 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; > > } This disables the ref clock. Should this be split into a separate function imx6_pcie_disable_ref_clk() for symmetry with the already existing imx6_pcie_enable_ref_clk() ? That could then also be used to disable pcie_inbound_axi in the error path of imx6_pcie_deassert_core_reset(). > > } > > > > +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 +847,11 @@ 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) > > regards Philipp
