[PATCH v2 2/3] PCI: apple: Integrate pwrctrl API

[Yureka Lilian]

Integrate the PCI pwrctrl framework into the Apple PCIe host driver to
provide standardized power management for PCI devices.

Notably, this allows enabling powering on the WiFi, SD card reader on
various Macs by means of the pwrctrl framework before probing the ports.

Signed-off-by: Yureka Lilian <yureka@xxxxxxxxxxxxxx>
---
 drivers/pci/controller/Kconfig      |  1 +
 drivers/pci/controller/pcie-apple.c | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index d246bbe37948..791892a6c0c6 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -46,6 +46,7 @@ config PCIE_APPLE
 	depends on OF
 	depends on PCI_MSI
 	select PCI_HOST_COMMON
+	select PCI_PWRCTRL_GENERIC
 	select IRQ_MSI_LIB
 	help
 	  Say Y here if you want to enable PCIe controller support on Apple
diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
index c2cffc0659f4..2d32092e2122 100644
--- a/drivers/pci/controller/pcie-apple.c
+++ b/drivers/pci/controller/pcie-apple.c
@@ -30,6 +30,7 @@
 #include <linux/msi.h>
 #include <linux/of_irq.h>
 #include <linux/pci-ecam.h>
+#include <linux/pci-pwrctrl.h>
 
 #include "pci-host-common.h"
 
@@ -825,6 +826,28 @@ static int apple_pcie_init(struct pci_config_window *cfg)
 	if (WARN_ON(!pcie))
 		return -ENOENT;
 
+	// Ensure all ports can be powered on before attempting initialization
+	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
+		ret = pci_pwrctrl_create_device(of_port, pcie->dev);
+		if (ret) {
+			dev_err(pcie->dev, "Failed to create pwrctrl device: %pe\n", ERR_PTR(ret));
+			return ret;
+		}
+
+		ret = pci_pwrctrl_power_on_device(of_port);
+		if (ret) {
+			if (ret != -EPROBE_DEFER) {
+				dev_err(pcie->dev,
+					"Failed to power on device: %pe\n",
+					ERR_PTR(ret));
+				for_each_available_child_of_node_scoped(dev->of_node, of_port) {
+					pci_pwrctrl_destroy_device(of_port);
+				}
+			}
+			return ret;
+		}
+	}
+
 	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
 		ret = apple_pcie_setup_port(pcie, of_port);
 		if (ret) {

-- 
2.56.0