PCI: aardvark: Implement driver 'remove' function and allow to build …

…it as module

Providing driver's 'remove' function allows kernel to bind and unbind devices
from aardvark driver. It also allows to build aardvark driver as a module.

Compiling aardvark as a module simplifies development and debugging of
this driver as it can be reloaded at runtime without the need to reboot
to new kernel.

Link: https://lore.kernel.org/r/20200907111038.5811-5-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>

drivers/pci/controller/Kconfig

@@ -12,7 +12,7 @@ config PCI_MVEBU
 	select PCI_BRIDGE_EMUL
 
 config PCI_AARDVARK
-	bool "Aardvark PCIe controller"
+	tristate "Aardvark PCIe controller"
 	depends on (ARCH_MVEBU && ARM64) || COMPILE_TEST
 	depends on OF
 	depends on PCI_MSI_IRQ_DOMAIN

drivers/pci/controller/pci-aardvark.c

@@ -14,6 +14,7 @@
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/phy/phy.h>
@@ -1121,6 +1122,7 @@ static int advk_pcie_probe(struct platform_device *pdev)
 
 	pcie = pci_host_bridge_priv(bridge);
 	pcie->pdev = pdev;
+	platform_set_drvdata(pdev, pcie);
 
 	pcie->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(pcie->base))
@@ -1198,18 +1200,37 @@ static int advk_pcie_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static int advk_pcie_remove(struct platform_device *pdev)
+{
+	struct advk_pcie *pcie = platform_get_drvdata(pdev);
+	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
+
+	pci_lock_rescan_remove();
+	pci_stop_root_bus(bridge->bus);
+	pci_remove_root_bus(bridge->bus);
+	pci_unlock_rescan_remove();
+
+	advk_pcie_remove_msi_irq_domain(pcie);
+	advk_pcie_remove_irq_domain(pcie);
+
+	return 0;
+}
+
 static const struct of_device_id advk_pcie_of_match_table[] = {
 	{ .compatible = "marvell,armada-3700-pcie", },
 	{},
 };
+MODULE_DEVICE_TABLE(of, advk_pcie_of_match_table);
 
 static struct platform_driver advk_pcie_driver = {
 	.driver = {
 		.name = "advk-pcie",
 		.of_match_table = advk_pcie_of_match_table,
-		/* Driver unloading/unbinding currently not supported */
-		.suppress_bind_attrs = true,
 	},
 	.probe = advk_pcie_probe,
+	.remove = advk_pcie_remove,
 };
-builtin_platform_driver(advk_pcie_driver);
+module_platform_driver(advk_pcie_driver);
+
+MODULE_DESCRIPTION("Aardvark PCIe controller");
+MODULE_LICENSE("GPL v2");