pcie.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * arch/arm/mach-dove/pcie.c
 *
 * PCIe functions for Marvell Dove 88AP510 SoC
 */

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/clk.h>
#include <video/vga.h>
#include <asm/mach/pci.h>
#include <asm/mach/arch.h>
#include <asm/setup.h>
#include <asm/delay.h>
#include <plat/pcie.h>
#include <plat/addr-map.h>
#include "irqs.h"
#include "bridge-regs.h"
#include "common.h"

struct pcie_port {
	u8			index;
	u8			root_bus_nr;
	void __iomem		*base;
	spinlock_t		conf_lock;
	char			mem_space_name[16];
	struct resource		res;
};

static struct pcie_port pcie_port[2];
static int num_pcie_ports;


static int __init dove_pcie_setup(int nr, struct pci_sys_data *sys)
{
	struct pcie_port *pp;
	struct resource realio;

	if (nr >= num_pcie_ports)
		return 0;

	pp = &pcie_port[nr];
	sys->private_data = pp;
	pp->root_bus_nr = sys->busnr;

	/*
	 * Generic PCIe unit setup.
	 */
	orion_pcie_set_local_bus_nr(pp->base, sys->busnr);

	orion_pcie_setup(pp->base);

	realio.start = sys->busnr * SZ_64K;
	realio.end = realio.start + SZ_64K - 1;
	pci_remap_iospace(&realio, pp->index == 0 ? DOVE_PCIE0_IO_PHYS_BASE :
						    DOVE_PCIE1_IO_PHYS_BASE);

	/*
	 * IORESOURCE_MEM
	 */
	snprintf(pp->mem_space_name, sizeof(pp->mem_space_name),
		 "PCIe %d MEM", pp->index);
	pp->mem_space_name[sizeof(pp->mem_space_name) - 1] = 0;
	pp->res.name = pp->mem_space_name;
	if (pp->index == 0) {
		pp->res.start = DOVE_PCIE0_MEM_PHYS_BASE;
		pp->res.end = pp->res.start + DOVE_PCIE0_MEM_SIZE - 1;
	} else {
		pp->res.start = DOVE_PCIE1_MEM_PHYS_BASE;
		pp->res.end = pp->res.start + DOVE_PCIE1_MEM_SIZE - 1;
	}
	pp->res.flags = IORESOURCE_MEM;
	if (request_resource(&iomem_resource, &pp->res))
		panic("Request PCIe Memory resource failed\n");
	pci_add_resource_offset(&sys->resources, &pp->res, sys->mem_offset);

	return 1;
}

static int pcie_valid_config(struct pcie_port *pp, int bus, int dev)
{
	/*
	 * Don't go out when trying to access nonexisting devices
	 * on the local bus.
	 */
	if (bus == pp->root_bus_nr && dev > 1)
		return 0;

	return 1;
}

static int pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
			int size, u32 *val)
{
	struct pci_sys_data *sys = bus->sysdata;
	struct pcie_port *pp = sys->private_data;
	unsigned long flags;
	int ret;

	if (pcie_valid_config(pp, bus->number, PCI_SLOT(devfn)) == 0) {
		*val = 0xffffffff;
		return PCIBIOS_DEVICE_NOT_FOUND;
	}

	spin_lock_irqsave(&pp->conf_lock, flags);
	ret = orion_pcie_rd_conf(pp->base, bus, devfn, where, size, val);
	spin_unlock_irqrestore(&pp->conf_lock, flags);

	return ret;
}

static int pcie_wr_conf(struct pci_bus *bus, u32 devfn,
			int where, int size, u32 val)
{
	struct pci_sys_data *sys = bus->sysdata;
	struct pcie_port *pp = sys->private_data;
	unsigned long flags;
	int ret;

	if (pcie_valid_config(pp, bus->number, PCI_SLOT(devfn)) == 0)
		return PCIBIOS_DEVICE_NOT_FOUND;

	spin_lock_irqsave(&pp->conf_lock, flags);
	ret = orion_pcie_wr_conf(pp->base, bus, devfn, where, size, val);
	spin_unlock_irqrestore(&pp->conf_lock, flags);

	return ret;
}

static struct pci_ops pcie_ops = {
	.read = pcie_rd_conf,
	.write = pcie_wr_conf,
};

/*
 * The root complex has a hardwired class of PCI_CLASS_MEMORY_OTHER, when it
 * is operating as a root complex this needs to be switched to
 * PCI_CLASS_BRIDGE_HOST or Linux will errantly try to process the BAR's on
 * the device. Decoding setup is handled by the orion code.
 */
static void rc_pci_fixup(struct pci_dev *dev)
{
	if (dev->bus->parent == NULL && dev->devfn == 0) {
		struct resource *r;

		dev->class &= 0xff;
		dev->class |= PCI_CLASS_BRIDGE_HOST << 8;
		pci_dev_for_each_resource(dev, r) {
			r->start = 0;
			r->end   = 0;
			r->flags = 0;
		}
	}
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MARVELL, PCI_ANY_ID, rc_pci_fixup);

static int __init
dove_pcie_scan_bus(int nr, struct pci_host_bridge *bridge)
{
	struct pci_sys_data *sys = pci_host_bridge_priv(bridge);

	if (nr >= num_pcie_ports) {
		BUG();
		return -EINVAL;
	}

	list_splice_init(&sys->resources, &bridge->windows);
	bridge->dev.parent = NULL;
	bridge->sysdata = sys;
	bridge->busnr = sys->busnr;
	bridge->ops = &pcie_ops;

	return pci_scan_root_bus_bridge(bridge);
}

static int __init dove_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
	struct pci_sys_data *sys = dev->sysdata;
	struct pcie_port *pp = sys->private_data;

	return pp->index ? IRQ_DOVE_PCIE1 : IRQ_DOVE_PCIE0;
}

static struct hw_pci dove_pci __initdata = {
	.nr_controllers	= 2,
	.setup		= dove_pcie_setup,
	.scan		= dove_pcie_scan_bus,
	.map_irq	= dove_pcie_map_irq,
};

static void __init add_pcie_port(int index, void __iomem *base)
{
	printk(KERN_INFO "Dove PCIe port %d: ", index);

	if (orion_pcie_link_up(base)) {
		struct pcie_port *pp = &pcie_port[num_pcie_ports++];
		struct clk *clk = clk_get_sys("pcie", (index ? "1" : "0"));

		if (!IS_ERR(clk))
			clk_prepare_enable(clk);

		printk(KERN_INFO "link up\n");

		pp->index = index;
		pp->root_bus_nr = -1;
		pp->base = base;
		spin_lock_init(&pp->conf_lock);
		memset(&pp->res, 0, sizeof(pp->res));
	} else {
		printk(KERN_INFO "link down, ignoring\n");
	}
}

void __init dove_pcie_init(int init_port0, int init_port1)
{
	vga_base = DOVE_PCIE0_MEM_PHYS_BASE;

	if (init_port0)
		add_pcie_port(0, DOVE_PCIE0_VIRT_BASE);

	if (init_port1)
		add_pcie_port(1, DOVE_PCIE1_VIRT_BASE);

	pci_common_init(&dove_pci);
}