From: Leonard Crestez <leonard.crestez@nxp.com>
To: Lucas Stach <l.stach@pengutronix.de>,
Philipp Zabel <p.zabel@pengutronix.de>,
Richard Zhu <hongxing.zhu@nxp.com>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>,
Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
Jingoo Han <jingoohan1@gmail.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Shawn Guo <shawnguo@kernel.org>,
Fabio Estevam <fabio.estevam@nxp.com>,
linux-imx@nxp.com, kernel@pengutronix.de,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 4/4] PCI: imx: Add PME_Turn_Off support
Date: Mon, 1 Oct 2018 22:53:48 +0300 [thread overview]
Message-ID: <1cf53d188657bba7df06ad417eb2a65160238196.1538423063.git.leonard.crestez@nxp.com> (raw)
In-Reply-To: <cover.1538423063.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 6ba16fd1373c..13cb1a200442 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 +813,16 @@ 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);
@@ -832,10 +839,11 @@ 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 +967,17 @@ 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:[~2018-10-01 19:54 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-01 19:53 [PATCH 0/4] PCI: imx: Add PME_Turn_Off support Leonard Crestez
2018-10-01 19:53 ` [PATCH 1/4] reset: imx7: Add PCIE_CTRL_APPS_TURNOFF Leonard Crestez
2018-10-01 19:53 ` [PATCH 2/4] dt-bindings: imx6q-pcie: Add turnoff reset for imx7d Leonard Crestez
2018-10-01 19:53 ` [PATCH 3/4] ARM: dts: imx7d: Add turnoff reset Leonard Crestez
2018-10-01 19:53 ` Leonard Crestez [this message]
2018-10-02 13:49 ` [PATCH 4/4] PCI: imx: Add PME_Turn_Off support Lorenzo Pieralisi
2018-10-04 8:59 ` Lucas Stach
2018-10-04 13:20 ` Leonard Crestez
2018-10-04 13:25 ` Philipp Zabel
2018-10-04 13:34 ` Lucas Stach
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