[PATCH 14/14] PCI: j721e: add suspend and resume support

[Thomas Richard <thomas.richard@bootlin.com>]

From: Théo Lebrun <theo.lebrun@bootlin.com>

Add suspend and resume support for rc mode.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
---
 drivers/pci/controller/cadence/pci-j721e.c    | 72 +++++++++++++++++++++++++++
 drivers/pci/controller/cadence/pcie-cadence.h |  3 +-
 2 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c
index 477275d72257..51867a3f2499 100644
--- a/drivers/pci/controller/cadence/pci-j721e.c
+++ b/drivers/pci/controller/cadence/pci-j721e.c
@@ -6,6 +6,7 @@
  * Author: Kishon Vijay Abraham I <kishon@ti.com>
  */
 
+#include <linux/clk-provider.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
@@ -554,6 +555,76 @@ static void j721e_pcie_remove(struct platform_device *pdev)
 	pm_runtime_disable(dev);
 }
 
+#ifdef CONFIG_PM
+static int j721e_pcie_suspend_noirq(struct device *dev)
+{
+	struct j721e_pcie *pcie = dev_get_drvdata(dev);
+
+	if (pcie->mode == PCI_MODE_RC) {
+		if (pcie->reset_gpio)
+			gpiod_set_value_cansleep(pcie->reset_gpio, 0);
+
+		clk_disable_unprepare(pcie->refclk);
+	}
+
+	cdns_pcie_disable_phy(pcie->cdns_pcie);
+
+	return 0;
+}
+
+static int j721e_pcie_resume_noirq(struct device *dev)
+{
+	struct j721e_pcie *pcie = dev_get_drvdata(dev);
+	struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
+	int ret;
+
+	ret = j721e_pcie_ctrl_init(pcie);
+	if (ret < 0) {
+		dev_err(dev, "j721e_pcie_ctrl_init failed\n");
+		return ret;
+	}
+
+	j721e_pcie_config_link_irq(pcie);
+
+	/*
+	 * This is not called explicitly in the probe, it is called by
+	 * cdns_pcie_init_phy.
+	 */
+	ret = cdns_pcie_enable_phy(pcie->cdns_pcie);
+	if (ret < 0) {
+		dev_err(dev, "cdns_pcie_enable_phy failed\n");
+		return -ENODEV;
+	}
+
+	if (pcie->mode == PCI_MODE_RC) {
+		struct cdns_pcie_rc *rc = cdns_pcie_to_rc(cdns_pcie);
+
+		ret = clk_prepare_enable(pcie->refclk);
+		if (ret < 0) {
+			dev_err(dev, "clk_prepare_enable failed\n");
+			return -ENODEV;
+		}
+
+		if (pcie->reset_gpio) {
+			usleep_range(100, 200);
+			gpiod_set_value_cansleep(pcie->reset_gpio, 1);
+		}
+
+		ret = cdns_pcie_host_setup(rc, false);
+		if (ret < 0) {
+			clk_disable_unprepare(pcie->refclk);
+			return -ENODEV;
+		}
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops j721e_pcie_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(j721e_pcie_suspend_noirq, j721e_pcie_resume_noirq)
+};
+#endif
+
 static struct platform_driver j721e_pcie_driver = {
 	.probe  = j721e_pcie_probe,
 	.remove_new = j721e_pcie_remove,
@@ -561,6 +632,7 @@ static struct platform_driver j721e_pcie_driver = {
 		.name	= "j721e-pcie",
 		.of_match_table = of_j721e_pcie_match,
 		.suppress_bind_attrs = true,
+		.pm	= pm_ptr(&j721e_pcie_pm_ops),
 	},
 };
 builtin_platform_driver(j721e_pcie_driver);
diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
index 3b0da889ed64..05d4b96fc71d 100644
--- a/drivers/pci/controller/cadence/pcie-cadence.h
+++ b/drivers/pci/controller/cadence/pcie-cadence.h
@@ -331,6 +331,8 @@ struct cdns_pcie_rc {
 	unsigned int		quirk_detect_quiet_flag:1;
 };
 
+#define cdns_pcie_to_rc(p) container_of(p, struct cdns_pcie_rc, pcie)
+
 /**
  * struct cdns_pcie_epf - Structure to hold info about endpoint function
  * @epf: Info about virtual functions attached to the physical function
@@ -381,7 +383,6 @@ struct cdns_pcie_ep {
 	unsigned int		quirk_disable_flr:1;
 };
 
-
 /* Register access */
 static inline void cdns_pcie_writel(struct cdns_pcie *pcie, u32 reg, u32 value)
 {

-- 
2.39.2