[PATCH 16/18] PCI: aardvark: Add suspend to RAM support

Marek Behún
2022-02-20T19:34:34Z

From: Miquel Raynal <miquel.raynal@bootlin.com>

Add suspend and resume callbacks. The priority of these are
"_noirq()", to workaround early access to the registers done by the
PCI core through the ->read()/->write() callbacks at resume time.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
---
drivers/pci/controller/pci-aardvark.c | 39 +++++++++++++++++++++++++++
1 file changed, 39 insertions(+)

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 3b51f47abd72..8c9ac7766ac7 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -1896,6 +1896,44 @@ static int advk_pcie_setup_phy(struct advk_pcie *pcie)
return ret;
}

+static int __maybe_unused advk_pcie_suspend(struct device *dev)
+{
+ struct advk_pcie *pcie = dev_get_drvdata(dev);
+
+ advk_pcie_disable_phy(pcie);
+
+ clk_disable_unprepare(pcie->clk);
+
+ return 0;
+}
+
+static int __maybe_unused advk_pcie_resume(struct device *dev)
+{
+ struct advk_pcie *pcie = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(pcie->clk);
+ if (ret)
+ return ret;
+
+ ret = advk_pcie_enable_phy(pcie);
+ if (ret)
+ return ret;
+
+ advk_pcie_setup_hw(pcie);
+
+ return 0;
+}
+
+/*
+ * The PCI core will try to reconfigure the bus quite early in the resume path.
+ * We must use the _noirq() alternatives to ensure the controller is ready when
+ * the core uses the ->read()/->write() callbacks.
+ */
+static const struct dev_pm_ops advk_pcie_dev_pm_ops = {
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(advk_pcie_suspend, advk_pcie_resume)
+};
+
static int advk_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -2171,6 +2209,7 @@ static struct platform_driver advk_pcie_driver = {
.driver = {
.name = "advk-pcie",
.of_match_table = advk_pcie_of_match_table,
+ .pm = &advk_pcie_dev_pm_ops,
},
.probe = advk_pcie_probe,
.remove = advk_pcie_remove,
--
2.34.1