| Message ID | 37d60fe2119361381a6a81f439fa1c3ad29db45e.1538670431.git.leonard.crestez@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI: imx: Add PME_Turn_Off support | expand |
Am Donnerstag, den 04.10.2018, 16:34 +0000 schrieb Leonard Crestez: > When the root complex suspends it must send a PME_Turn_Off TLP. > Implement this by asserting the "turnoff" reset. > > On imx7d this functionality is part of the SRC and exposed through the > linux reset-controller subsystem. On imx6 equivalent bits are in the > IOMUXC GPR area which the imx6-pcie driver accesses directly. > > This is only for imx7d right now but it's deliberately implemented as an > optional reset, ignoring the chip variant: > * Older dtbs won't have this reset so it will be ignored. > * Future chips might also expose this as a reset controller. > > For example imx8m (not yet supported) has the exact same > PCIE_CTRL_APPS_TURNOFF bit in the same location. > > Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Reviewed-by: Lucas Stach <l.stach@pengutronix.de> > --- > drivers/pci/controller/dwc/pci-imx6.c | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index 6ba16fd1373c..2bf80f1ad852 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -50,10 +50,11 @@ struct imx6_pcie { > > > struct clk *pcie_inbound_axi; > > > struct clk *pcie; > > > struct regmap *iomuxc_gpr; > > > struct reset_control *pciephy_reset; > > > struct reset_control *apps_reset; > > > + struct reset_control *turnoff_reset; > > enum imx6_pcie_variants variant; > > > u32 tx_deemph_gen1; > > > u32 tx_deemph_gen2_3p5db; > > > u32 tx_deemph_gen2_6db; > > > u32 tx_swing_full; > @@ -812,10 +813,25 @@ static void imx6_pcie_ltssm_disable(struct device *dev) > > default: > > dev_err(dev, "ltssm_disable not supported\n"); > > } > } > > +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); > + > > + /* > > + * 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. > > + */ > > + 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); > @@ -832,10 +848,11 @@ 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_pm_turnoff(imx6_pcie); > > imx6_pcie_clk_disable(imx6_pcie); > > imx6_pcie_ltssm_disable(dev); > > > return 0; > } > @@ -959,10 +976,17 @@ static int imx6_pcie_probe(struct platform_device *pdev) > > break; > > default: > > break; > > } > > > + /* Grab turnoff reset */ > > + imx6_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff"); > > + if (IS_ERR(imx6_pcie->turnoff_reset)) { > > + dev_err(dev, "Failed to get TURNOFF reset control\n"); > > + return PTR_ERR(imx6_pcie->turnoff_reset); > > + } > + > > /* Grab GPR config register range */ > > imx6_pcie->iomuxc_gpr = > > syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr"); > > if (IS_ERR(imx6_pcie->iomuxc_gpr)) { > > dev_err(dev, "unable to find iomuxc registers\n");
On Thu, Oct 04, 2018 at 04:34:30PM +0000, Leonard Crestez wrote: > When the root complex suspends it must send a PME_Turn_Off TLP. > Implement this by asserting the "turnoff" reset. > > On imx7d this functionality is part of the SRC and exposed through the > linux reset-controller subsystem. On imx6 equivalent bits are in the > IOMUXC GPR area which the imx6-pcie driver accesses directly. Nit: I am merging the series, please define what SRC and GPR are so that I can update the commit log accordingly, it must be clear to anyone reading it. Thanks, Lorenzo > This is only for imx7d right now but it's deliberately implemented as an > optional reset, ignoring the chip variant: > * Older dtbs won't have this reset so it will be ignored. > * Future chips might also expose this as a reset controller. > > For example imx8m (not yet supported) has the exact same > PCIE_CTRL_APPS_TURNOFF bit in the same location. > > Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> > --- > drivers/pci/controller/dwc/pci-imx6.c | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index 6ba16fd1373c..2bf80f1ad852 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -50,10 +50,11 @@ struct imx6_pcie { > struct clk *pcie_inbound_axi; > struct clk *pcie; > struct regmap *iomuxc_gpr; > struct reset_control *pciephy_reset; > struct reset_control *apps_reset; > + struct reset_control *turnoff_reset; > enum imx6_pcie_variants variant; > u32 tx_deemph_gen1; > u32 tx_deemph_gen2_3p5db; > u32 tx_deemph_gen2_6db; > u32 tx_swing_full; > @@ -812,10 +813,25 @@ static void imx6_pcie_ltssm_disable(struct device *dev) > default: > dev_err(dev, "ltssm_disable not supported\n"); > } > } > > +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); > + > + /* > + * 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. > + */ > + 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); > @@ -832,10 +848,11 @@ 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_pm_turnoff(imx6_pcie); > imx6_pcie_clk_disable(imx6_pcie); > imx6_pcie_ltssm_disable(dev); > > return 0; > } > @@ -959,10 +976,17 @@ static int imx6_pcie_probe(struct platform_device *pdev) > break; > default: > break; > } > > + /* Grab turnoff reset */ > + imx6_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff"); > + if (IS_ERR(imx6_pcie->turnoff_reset)) { > + dev_err(dev, "Failed to get TURNOFF reset control\n"); > + return PTR_ERR(imx6_pcie->turnoff_reset); > + } > + > /* Grab GPR config register range */ > imx6_pcie->iomuxc_gpr = > syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr"); > if (IS_ERR(imx6_pcie->iomuxc_gpr)) { > dev_err(dev, "unable to find iomuxc registers\n"); > -- > 2.17.1 >
Hi Lorenzo, On Fri, 2018-10-05 at 11:29 +0100, Lorenzo Pieralisi wrote: > On Thu, Oct 04, 2018 at 04:34:30PM +0000, Leonard Crestez wrote: > > When the root complex suspends it must send a PME_Turn_Off TLP. > > Implement this by asserting the "turnoff" reset. > > > > On imx7d this functionality is part of the SRC and exposed through the > > linux reset-controller subsystem. On imx6 equivalent bits are in the > > IOMUXC GPR area which the imx6-pcie driver accesses directly. > > Nit: I am merging the series, please define what SRC and GPR are so > that I can update the commit log accordingly, it must be clear to > anyone reading it. SRC is the System Reset Controller, which controls reset signals to all kinds of devices, among them the PCIe PHY. IOMUXC GPR is a General Purpose Register range in the IOMUXC (pinmux controller) that is used to control various signals all over the SoC. regards Philipp
On Fri, Oct 05, 2018 at 12:59:16PM +0200, Philipp Zabel wrote: > Hi Lorenzo, > > On Fri, 2018-10-05 at 11:29 +0100, Lorenzo Pieralisi wrote: > > On Thu, Oct 04, 2018 at 04:34:30PM +0000, Leonard Crestez wrote: > > > When the root complex suspends it must send a PME_Turn_Off TLP. > > > Implement this by asserting the "turnoff" reset. > > > > > > On imx7d this functionality is part of the SRC and exposed through the > > > linux reset-controller subsystem. On imx6 equivalent bits are in the > > > IOMUXC GPR area which the imx6-pcie driver accesses directly. > > > > Nit: I am merging the series, please define what SRC and GPR are so > > that I can update the commit log accordingly, it must be clear to > > anyone reading it. > > SRC is the System Reset Controller, which controls reset signals to all > kinds of devices, among them the PCIe PHY. > > IOMUXC GPR is a General Purpose Register range in the IOMUXC (pinmux > controller) that is used to control various signals all over the SoC. Thanks Philipp. Updated the commit log and pushed out the series for v4.20 (branch pci/dwc - I have just updated this patch log). Thanks, Lorenzo
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index 6ba16fd1373c..2bf80f1ad852 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -50,10 +50,11 @@ struct imx6_pcie { struct clk *pcie_inbound_axi; struct clk *pcie; struct regmap *iomuxc_gpr; struct reset_control *pciephy_reset; struct reset_control *apps_reset; + struct reset_control *turnoff_reset; enum imx6_pcie_variants variant; u32 tx_deemph_gen1; u32 tx_deemph_gen2_3p5db; u32 tx_deemph_gen2_6db; u32 tx_swing_full; @@ -812,10 +813,25 @@ static void imx6_pcie_ltssm_disable(struct device *dev) default: dev_err(dev, "ltssm_disable not supported\n"); } } +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); + + /* + * 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. + */ + 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); @@ -832,10 +848,11 @@ 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_pm_turnoff(imx6_pcie); imx6_pcie_clk_disable(imx6_pcie); imx6_pcie_ltssm_disable(dev); return 0; } @@ -959,10 +976,17 @@ static int imx6_pcie_probe(struct platform_device *pdev) break; default: break; } + /* Grab turnoff reset */ + imx6_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff"); + if (IS_ERR(imx6_pcie->turnoff_reset)) { + dev_err(dev, "Failed to get TURNOFF reset control\n"); + return PTR_ERR(imx6_pcie->turnoff_reset); + } + /* Grab GPR config register range */ imx6_pcie->iomuxc_gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr"); if (IS_ERR(imx6_pcie->iomuxc_gpr)) { dev_err(dev, "unable to find iomuxc registers\n");
When the root complex suspends it must send a PME_Turn_Off TLP. Implement this by asserting the "turnoff" reset. On imx7d this functionality is part of the SRC and exposed through the linux reset-controller subsystem. On imx6 equivalent bits are in the IOMUXC GPR area which the imx6-pcie driver accesses directly. This is only for imx7d right now but it's deliberately implemented as an optional reset, ignoring the chip variant: * Older dtbs won't have this reset so it will be ignored. * Future chips might also expose this as a reset controller. For example imx8m (not yet supported) has the exact same PCIE_CTRL_APPS_TURNOFF bit in the same location. Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> --- drivers/pci/controller/dwc/pci-imx6.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)