From mboxrd@z Thu Jan 1 00:00:00 1970 From: l.stach@pengutronix.de (Lucas Stach) Date: Fri, 08 Jun 2018 16:33:42 +0200 Subject: [PATCH 2/2] PCI: imx: Initial imx7d pm support In-Reply-To: References: Message-ID: <1528468422.26356.20.camel@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Am Dienstag, den 29.05.2018, 22:39 +0300 schrieb Leonard Crestez: > On imx7d the phy is turned off in suspend and must be reset on resume. > Right now lspci -v fails after a suspend/resume cycle, fix this by > adding minimal suspend/resume code from the nxp vendor tree. > > This is currently only enabled for imx7 but the same sequence can be > applied to other imx pcie variants. > > Tested on imx7d-sabresd with an Intel 5622ANHMW wireless pcie adapter. > > > The original author is mostly Richard Zhu , this > patch adjusts the code to the upstream imx7d implemention using reset > controls and power domains. > > > Signed-off-by: Leonard Crestez > --- > ?drivers/pci/dwc/pci-imx6.c | 94 ++++++++++++++++++++++++++++++++++++-- > ?1 file changed, 89 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c > index 4818ef875f8a..ff6077eeb387 100644 > --- a/drivers/pci/dwc/pci-imx6.c > +++ b/drivers/pci/dwc/pci-imx6.c > @@ -540,10 +540,27 @@ 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); > > + } > +} > + > ?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 +575,11 @@ 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; > ? > @@ -681,10 +694,80 @@ 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 int imx6_pcie_suspend_noirq(struct device *dev) > +{ > > + struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev); > + > + if (imx6_pcie->variant == IMX7D) { Instead of this large indented block, please just have an early return at the start of this function, like: if (imx6_pcie->variant != IMX7D) return 0; Same for the resume function. > + /* Disable clks */ > > + clk_disable_unprepare(imx6_pcie->pcie); > > + clk_disable_unprepare(imx6_pcie->pcie_phy); > > + clk_disable_unprepare(imx6_pcie->pcie_bus); > > + /* turn off external osc input */ > > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, > > + ???IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, > > + ???IMX7D_GPR12_PCIE_PHY_REFCLK_SEL); > > + } > + > > + return 0; > +} > + > +static void imx6_pcie_ltssm_disable(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, 0); > > + break; > > + case IMX7D: > > + reset_control_assert(imx6_pcie->apps_reset); > > + break; > > + } > +} > + > +static int imx6_pcie_resume_noirq(struct device *dev) > +{ > > + int ret = 0; > > + struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev); > > + struct pcie_port *pp = &imx6_pcie->pci->pp; > + > > + if (imx6_pcie->variant == IMX7D) { > > + imx6_pcie_ltssm_disable(dev); The LTSSM disable seems misplaced here. I would have expected it to be in the suspend function. > + imx6_pcie_assert_core_reset(imx6_pcie); > > + imx6_pcie_init_phy(imx6_pcie); > > + imx6_pcie_deassert_core_reset(imx6_pcie); > + > > + /* > > + ?* controller maybe turn off, re-configure again > > + ?*/ > > + dw_pcie_setup_rc(pp); > + > > + imx6_pcie_ltssm_enable(dev); > + > > + ret = imx6_pcie_wait_for_link(imx6_pcie); > > + if (ret < 0) > + pr_info("pcie link is down after resume.\n"); If the PHY has been powered down and LTSSM stopped I guess we need to do the full imx6_pcie_establish_link() dance again here to reliably re- establish the link. The above seems unsafe. > + } > + > > + return 0; > +} > + > +static const struct dev_pm_ops imx6_pcie_pm_ops = { > > + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx6_pcie_suspend_noirq, > > + ??????imx6_pcie_resume_noirq) > +}; > +#endif This structure must be outside of the ifdef, or you'll break the build on !CONFIG_PM_SLEEP. > ?static int imx6_pcie_probe(struct platform_device *pdev) > ?{ > > ? struct device *dev = &pdev->dev; > > ? struct dw_pcie *pci; > > ? struct imx6_pcie *imx6_pcie; > @@ -847,10 +930,11 @@ 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, > ?}; > ? Regards, Lucas