From: Leonard Crestez <leonard.crestez@nxp.com>
To: Shawn Guo <shawnguo@kernel.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Philipp Zabel <p.zabel@pengutronix.de>,
Lucas Stach <l.stach@pengutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>,
devicetree@vger.kernel.org, Joao Pinto <Joao.Pinto@synopsys.com>,
Richard Zhu <hongxing.zhu@nxp.com>,
Anson Huang <Anson.Huang@nxp.com>,
Andrey Smirnov <andrew.smirnov@gmail.com>,
Jingoo Han <jingoohan1@gmail.com>,
linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
linux-imx@nxp.com, kernel@pengutronix.de,
linux-pci@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 2/6] PCI: imx: Initial imx7d pm support
Date: Tue, 14 Aug 2018 19:50:16 +0300 [thread overview]
Message-ID: <4b786ba5d84a0ba90d2f04beacedb0de1e529fd8.1534264292.git.leonard.crestez@nxp.com> (raw)
In-Reply-To: <cover.1534264292.git.leonard.crestez@nxp.com>
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 <hongxing.zhu@nxp.com>, this
patch adjusts the code to the upstream imx7d implemention using reset
controls and power domains.
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
---
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 84c33e0c049d..926858701726 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -584,10 +584,28 @@ 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;
@@ -602,15 +620,11 @@ 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;
@@ -724,10 +738,82 @@ 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;
@@ -894,10 +980,11 @@ 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,
};
--
2.17.1
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next prev parent reply other threads:[~2018-08-14 16:50 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-14 16:50 [PATCH v4 0/6] PCI: imx: Initial imx7d suspend/resume support Leonard Crestez
2018-08-14 16:50 ` [PATCH v4 1/6] Revert "ARM: dts: imx7d: Invert legacy PCI irq mapping" Leonard Crestez
2018-08-14 16:50 ` Leonard Crestez [this message]
2018-08-14 16:50 ` [PATCH v4 3/6] reset: imx7: Add PCIE_CTRL_APPS_TURNOFF Leonard Crestez
2018-08-15 20:24 ` Rob Herring
2018-08-14 16:50 ` [PATCH v4 4/6] dt-bindings: imx6q-pcie: Add turnoff reset for imx7d Leonard Crestez
2018-08-15 20:26 ` Rob Herring
2018-08-14 16:50 ` [PATCH v4 5/6] ARM: dts: imx7d: Add turnoff reset Leonard Crestez
2018-09-25 9:20 ` Shawn Guo
2018-08-14 16:50 ` [PATCH v4 6/6] PCI: imx: Add PME_Turn_Off support Leonard Crestez
2018-09-17 15:09 ` [PATCH v4 0/6] PCI: imx: Initial imx7d suspend/resume support Lorenzo Pieralisi
2018-09-17 15:09 ` Lorenzo Pieralisi
2018-09-17 16:01 ` Leonard Crestez
2018-09-17 16:01 ` Leonard Crestez
2018-09-17 16:52 ` Lorenzo Pieralisi
2018-09-17 16:52 ` Lorenzo Pieralisi
2018-09-17 17:15 ` Leonard Crestez
2018-09-17 17:15 ` Leonard Crestez
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