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: Andrey Smirnov <andrew.smirnov@gmail.com>,
Richard Zhu <hongxing.zhu@nxp.com>,
Anson Huang <Anson.Huang@nxp.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Jingoo Han <jingoohan1@gmail.com>,
Joao Pinto <Joao.Pinto@synopsys.com>,
linux-pci@vger.kernel.org, linux-imx@nxp.com,
kernel@pengutronix.de, linux-arm-kernel@lists.infradead.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>
Subject: [PATCH v4 6/6] PCI: imx: Add PME_Turn_Off support
Date: Tue, 14 Aug 2018 19:50:20 +0300 [thread overview]
Message-ID: <7079253f4622c78a6c8a911dda1df60a3198a9a9.1534264292.git.leonard.crestez@nxp.com> (raw)
In-Reply-To: <cover.1534264292.git.leonard.crestez@nxp.com>
When the root complex suspends it must send a PME_Turn_Off TLP.
Implement this by asserting the "turnoff" reset.
On imx7d this is 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 | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 926858701726..eeba64392dba 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;
@@ -757,10 +758,16 @@ 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);
+}
+
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);
@@ -777,10 +784,11 @@ 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;
}
@@ -904,10 +912,17 @@ 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
next prev parent reply other threads:[~2018-08-14 16:51 UTC|newest]
Thread overview: 14+ 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 ` [PATCH v4 2/6] PCI: imx: Initial imx7d pm support Leonard Crestez
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 ` Leonard Crestez [this message]
2018-09-17 15:09 ` [PATCH v4 0/6] PCI: imx: Initial imx7d suspend/resume support Lorenzo Pieralisi
2018-09-17 16:01 ` Leonard Crestez
2018-09-17 16:52 ` Lorenzo Pieralisi
2018-09-17 17:15 ` Leonard Crestez
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