[PATCH v3 4/4] PCI: tegra: Use new pci_register_host_bridge() interface

[Thierry Reding <thierry.reding@gmail.com>]

From: Arnd Bergmann <arnd@arndb.de>

Tegra is one of the remaining platforms that still use the traditional
pci_common_init_dev() interface for probing PCI host bridges.

This demonstrates how to convert it to the pci_register_host interface
I just added in a previous patch. This leads to a more linear probe
sequence that can handle errors better because we avoid callbacks into
the driver, and it makes the driver architecture independent.

As a side note, I should mention that I noticed this driver does not
register any IORESOURCE_IO resource with the bus, but instead registers
the I/O port window as a memory resource, which is surely a bug.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/pci/host/pci-tegra.c | 99 +++++++++++++++++++++++---------------------
 1 file changed, 52 insertions(+), 47 deletions(-)

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 2d520755b1d7..6737d1be9798 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -260,6 +260,7 @@ static inline struct tegra_msi *to_tegra_msi(struct msi_controller *chip)
 }
 
 struct tegra_pcie {
+	struct pci_host_bridge *bridge;
 	struct device *dev;
 
 	void __iomem *pads;
@@ -322,11 +323,6 @@ struct tegra_pcie_bus {
 	unsigned int nr;
 };
 
-static inline struct tegra_pcie *sys_to_pcie(struct pci_sys_data *sys)
-{
-	return sys->private_data;
-}
-
 static inline void afi_writel(struct tegra_pcie *pcie, u32 value,
 			      unsigned long offset)
 {
@@ -430,7 +426,8 @@ free:
 
 static int tegra_pcie_add_bus(struct pci_bus *bus)
 {
-	struct tegra_pcie *pcie = sys_to_pcie(bus->sysdata);
+	struct pci_host_bridge *host = pci_find_host_bridge(bus);
+	struct tegra_pcie *pcie = host->private;
 	struct tegra_pcie_bus *b;
 
 	b = tegra_pcie_bus_alloc(pcie, bus->number);
@@ -444,7 +441,8 @@ static int tegra_pcie_add_bus(struct pci_bus *bus)
 
 static void tegra_pcie_remove_bus(struct pci_bus *child)
 {
-	struct tegra_pcie *pcie = sys_to_pcie(child->sysdata);
+	struct pci_host_bridge *host = pci_find_host_bridge(child);
+	struct tegra_pcie *pcie = host->private;
 	struct tegra_pcie_bus *bus, *tmp;
 
 	list_for_each_entry_safe(bus, tmp, &pcie->buses, list) {
@@ -461,7 +459,8 @@ static void __iomem *tegra_pcie_map_bus(struct pci_bus *bus,
 					unsigned int devfn,
 					int where)
 {
-	struct tegra_pcie *pcie = sys_to_pcie(bus->sysdata);
+	struct pci_host_bridge *host = pci_find_host_bridge(bus);
+	struct tegra_pcie *pcie = host->private;
 	void __iomem *addr = NULL;
 
 	if (bus->number == 0) {
@@ -609,35 +608,29 @@ static void tegra_pcie_relax_enable(struct pci_dev *dev)
 }
 DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, tegra_pcie_relax_enable);
 
-static int tegra_pcie_setup(int nr, struct pci_sys_data *sys)
+static int tegra_pcie_request_resources(struct tegra_pcie *pcie)
 {
-	struct tegra_pcie *pcie = sys_to_pcie(sys);
+	struct list_head *windows = &pcie->bridge->windows;
 	int err;
 
-	sys->mem_offset = pcie->offset.mem;
-	sys->io_offset = pcie->offset.io;
-
-	err = devm_request_resource(pcie->dev, &iomem_resource, &pcie->io);
-	if (err < 0)
-		return err;
-
-	pci_add_resource_offset(&sys->resources, &pcie->pio, sys->io_offset);
-	pci_add_resource_offset(&sys->resources, &pcie->mem, sys->mem_offset);
-	pci_add_resource_offset(&sys->resources, &pcie->prefetch,
-				sys->mem_offset);
-	pci_add_resource(&sys->resources, &pcie->busn);
+	pci_add_resource_offset(windows, &pcie->pio, pcie->offset.io);
+	pci_add_resource_offset(windows, &pcie->mem, pcie->offset.mem);
+	pci_add_resource_offset(windows, &pcie->prefetch, pcie->offset.mem);
+	pci_add_resource(windows, &pcie->busn);
 
-	err = devm_request_pci_bus_resources(pcie->dev, &sys->resources);
+	err = devm_request_pci_bus_resources(pcie->dev, windows);
 	if (err < 0)
 		return err;
 
 	pci_remap_iospace(&pcie->pio, pcie->io.start);
-	return 1;
+
+	return 0;
 }
 
 static int tegra_pcie_map_irq(const struct pci_dev *pdev, u8 slot, u8 pin)
 {
-	struct tegra_pcie *pcie = sys_to_pcie(pdev->bus->sysdata);
+	struct pci_host_bridge *host = pci_find_host_bridge(pdev->bus);
+	struct tegra_pcie *pcie = host->private;
 	int irq;
 
 	tegra_cpuidle_pcie_irqs_in_use();
@@ -1544,6 +1537,8 @@ static int tegra_pcie_enable_msi(struct tegra_pcie *pcie)
 	reg |= AFI_INTR_MASK_MSI_MASK;
 	afi_writel(pcie, reg, AFI_INTR_MASK);
 
+	pcie->bridge->msi = &msi->chip;
+
 	return 0;
 
 err:
@@ -2006,10 +2001,9 @@ retry:
 	return false;
 }
 
-static int tegra_pcie_enable(struct tegra_pcie *pcie)
+static void tegra_pcie_enable_ports(struct tegra_pcie *pcie)
 {
 	struct tegra_pcie_port *port, *tmp;
-	struct hw_pci hw;
 
 	list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
 		dev_info(pcie->dev, "probing port %u, using %u lanes\n",
@@ -2025,22 +2019,6 @@ static int tegra_pcie_enable(struct tegra_pcie *pcie)
 		tegra_pcie_port_disable(port);
 		tegra_pcie_port_free(port);
 	}
-
-	memset(&hw, 0, sizeof(hw));
-
-#ifdef CONFIG_PCI_MSI
-	hw.msi_ctrl = &pcie->msi.chip;
-#endif
-
-	hw.nr_controllers = 1;
-	hw.private_data = (void **)&pcie;
-	hw.setup = tegra_pcie_setup;
-	hw.map_irq = tegra_pcie_map_irq;
-	hw.ops = &tegra_pcie_ops;
-
-	pci_common_init_dev(pcie->dev, &hw);
-
-	return 0;
 }
 
 static const struct tegra_pcie_soc tegra20_pcie = {
@@ -2201,13 +2179,18 @@ remove:
 
 static int tegra_pcie_probe(struct platform_device *pdev)
 {
+	struct pci_host_bridge *bridge;
 	struct tegra_pcie *pcie;
+	struct pci_bus *child;
 	int err;
 
-	pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
-	if (!pcie)
+	bridge = pci_alloc_host_bridge(sizeof(*pcie));
+	if (!bridge)
 		return -ENOMEM;
 
+	pcie = bridge->private;
+	pcie->bridge = bridge;
+
 	pcie->soc = of_device_get_match_data(&pdev->dev);
 	INIT_LIST_HEAD(&pcie->buses);
 	INIT_LIST_HEAD(&pcie->ports);
@@ -2227,6 +2210,10 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 	if (err)
 		goto put_resources;
 
+	err = tegra_pcie_request_resources(pcie);
+	if (err)
+		goto put_resources;
+
 	/* setup the AFI address translations */
 	tegra_pcie_setup_translations(pcie);
 
@@ -2240,12 +2227,30 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 		}
 	}
 
-	err = tegra_pcie_enable(pcie);
+	tegra_pcie_enable_ports(pcie);
+
+	pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
+	bridge->busnr = pcie->busn.start;
+	bridge->dev.parent = &pdev->dev;
+	bridge->ops = &tegra_pcie_ops;
+
+	err = pci_register_host_bridge(bridge);
 	if (err < 0) {
-		dev_err(&pdev->dev, "failed to enable PCIe ports: %d\n", err);
+		dev_err(&pdev->dev, "failed to register host: %d\n", err);
 		goto disable_msi;
 	}
 
+	pci_scan_child_bus(bridge->bus);
+
+	pci_fixup_irqs(pci_common_swizzle, tegra_pcie_map_irq);
+	pci_bus_size_bridges(bridge->bus);
+	pci_bus_assign_resources(bridge->bus);
+
+	list_for_each_entry(child, &bridge->bus->children, node)
+		pcie_bus_configure_settings(child);
+
+	pci_bus_add_devices(bridge->bus);
+
 	if (IS_ENABLED(CONFIG_DEBUG_FS)) {
 		err = tegra_pcie_debugfs_init(pcie);
 		if (err < 0)
-- 
2.9.0