[PATCH v4] pci: dwc: dra7xx: Add shutdown handler to cleanly turn off clocks

[Keerthy]

Add shutdown handler to cleanly turn off clocks. This will help
in cases of kexec where in a new kernel can boot abruptly.

Signed-off-by: Keerthy <j-keerthy@xxxxxx>
Acked-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---

Changes in v4:

  * Added the missing changes from v2!

Changes in v3:

  * Pushed the function outside #ifdef CONFIG_PM_SLEEP.
  * Added more details to commit log.

Changes in v2:

  * used a local dev pointer instead of dereferencing dev at multiple places.
  * dra7xx_pcie_stop_link before disabling clks in the shutdown path.

 drivers/pci/dwc/pci-dra7xx.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index 34427a6..d084800 100644
--- a/drivers/pci/dwc/pci-dra7xx.c
+++ b/drivers/pci/dwc/pci-dra7xx.c
@@ -794,6 +794,22 @@ static int dra7xx_pcie_resume_noirq(struct device *dev)
 }
 #endif
 
+void dra7xx_pcie_shutdown(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct dra7xx_pcie *dra7xx = dev_get_drvdata(dev);
+	int ret;
+
+	dra7xx_pcie_stop_link(dra7xx->pci);
+
+	ret = pm_runtime_put_sync(dev);
+	if (ret < 0)
+		dev_dbg(dev, "pm_runtime_put_sync failed\n");
+
+	pm_runtime_disable(dev);
+	dra7xx_pcie_disable_phy(dra7xx);
+}
+
 static const struct dev_pm_ops dra7xx_pcie_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(dra7xx_pcie_suspend, dra7xx_pcie_resume)
 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(dra7xx_pcie_suspend_noirq,
@@ -807,5 +823,6 @@ static int dra7xx_pcie_resume_noirq(struct device *dev)
 		.suppress_bind_attrs = true,
 		.pm	= &dra7xx_pcie_pm_ops,
 	},
+	.shutdown = dra7xx_pcie_shutdown,
 };
 builtin_platform_driver_probe(dra7xx_pcie_driver, dra7xx_pcie_probe);
-- 
1.9.1