/* SPDX-License-Identifier: GPL-2.0-only */

#include <assert.h>
#include <commonlib/helpers.h>
#include <console/console.h>
#include <device/device.h>
#include <device/pci.h>
#include <device/pci_def.h>
#include <device/pciexp.h>
#include <device/pci_ids.h>
#include <device/pci_ops.h>
#include "pch.h"
#include <southbridge/intel/common/gpio.h>
#include <stddef.h>
#include <stdint.h>
#include "chip.h"

#define MAX_NUM_ROOT_PORTS 8

struct root_port_config {
	/* RPFN is a write-once register so keep a copy until it is written */
	u32 orig_rpfn;
	u32 new_rpfn;
	u32 pin_ownership;
	u32 strpfusecfg1;
	u32 strpfusecfg2;
	u32 strpfusecfg3;
	u32 b0d28f0_32c;
	u32 b0d28f4_32c;
	u32 b0d28f5_32c;
	int coalesce;
	int gbe_port;
	int num_ports;
	struct device *ports[MAX_NUM_ROOT_PORTS];
};

static struct root_port_config rpc;

static inline int max_root_ports(void)
{
	if (pch_is_lp() || pch_silicon_id() == PCI_DEVICE_ID_INTEL_LPT_H81)
		return 6;

	return 8;
}

static inline int root_port_is_first(struct device *dev)
{
	return PCI_FUNC(dev->path.pci.devfn) == 0;
}

static inline int root_port_is_last(struct device *dev)
{
	return PCI_FUNC(dev->path.pci.devfn) == (rpc.num_ports - 1);
}

/* Root ports are numbered 1..N in the documentation. */
static inline int root_port_number(struct device *dev)
{
	return PCI_FUNC(dev->path.pci.devfn) + 1;
}

static bool is_rp_enabled(int rp)
{
	ASSERT(rp > 0 && rp <= ARRAY_SIZE(rpc.ports));

	if (rpc.ports[rp - 1] == NULL)
		return false;

	return rpc.ports[rp - 1]->enabled;
}

static void root_port_config_update_gbe_port(void)
{
	/* Is the Gbe Port enabled? */
	if (!((rpc.strpfusecfg1 >> 19) & 1))
		return;

	if (pch_is_lp()) {
		switch ((rpc.strpfusecfg1 >> 16) & 0x7) {
		case 0:
			rpc.gbe_port = 3;
			break;
		case 1:
			rpc.gbe_port = 4;
			break;
		case 2:
		case 3:
		case 4:
		case 5:
			/* Lanes 0-4 of Root Port 5. */
			rpc.gbe_port = 5;
			break;
		default:
			printk(BIOS_DEBUG, "Invalid GbE Port Selection.\n");
		}
	} else {
		/* Non-LP has 1:1 mapping with root ports. */
		rpc.gbe_port = ((rpc.strpfusecfg1 >> 16) & 0x7) + 1;
	}
}

static void update_num_ports(void)
{
	/*
	 * According to existing code in 'root_port_check_disable()', which does
	 * not agree with the confusing information on the datasheets, the last
	 * visible function depends on the strapped root port width as follows:
	 *
	 * +-----+----+----+----+----+
	 * | RPC | #5 | #6 | #7 | #8 |
	 * +-----+----+----+----+----+
	 * |  0  | x1 | x1 | x1 | x1 |
	 * |  1  | x2 |    | x1 | x1 |
	 * |  2  | x2 |    | x2 |    |
	 * |  3  | x4 |    |    |    |
	 * +-----+----+----+----+----+
	 */
	switch ((rpc.strpfusecfg2 >> 14) & 0x3) {
	case 0:
	case 1:
		break;
	case 2:
		rpc.num_ports = MIN(rpc.num_ports, 7);
		break;
	case 3:
		rpc.num_ports = MIN(rpc.num_ports, 5);
		break;
	}

	printk(BIOS_DEBUG, "Adjusted number of PCIe root ports to %d as per strpfusecfg2\n",
	       rpc.num_ports);
}

static void root_port_init_config(struct device *dev)
{
	int rp;

	if (root_port_is_first(dev)) {
		rpc.orig_rpfn = RCBA32(RPFN);
		rpc.new_rpfn = rpc.orig_rpfn;
		rpc.num_ports = max_root_ports();
		rpc.gbe_port = -1;

		rpc.pin_ownership = pci_read_config32(dev, 0x410);
		root_port_config_update_gbe_port();

		if (dev->chip_info != NULL) {
			struct southbridge_intel_lynxpoint_config *config;

			config = dev->chip_info;
			rpc.coalesce = config->pcie_port_coalesce;
		}
	}

	rp = root_port_number(dev);
	if (rp > rpc.num_ports) {
		printk(BIOS_ERR, "Found Root Port %d, expecting %d\n",
		       rp, rpc.num_ports);
		return;
	}

	/* Read the fuse configuration and pin ownership. */
	switch (rp) {
	case 1:
		rpc.strpfusecfg1 = pci_read_config32(dev, 0xfc);
		rpc.b0d28f0_32c = pci_read_config32(dev, 0x32c);
		break;
	case 5:
		rpc.strpfusecfg2 = pci_read_config32(dev, 0xfc);
		rpc.b0d28f4_32c = pci_read_config32(dev, 0x32c);

		if (!pch_is_lp())
			update_num_ports();

		break;
	case 6:
		rpc.b0d28f5_32c = pci_read_config32(dev, 0x32c);
		rpc.strpfusecfg3 = pci_read_config32(dev, 0xfc);
		break;
	default:
		break;
	}

	/* Cache pci device. */
	rpc.ports[rp - 1] = dev;
}

/* Update devicetree with new Root Port function number assignment */
static void pch_pcie_device_set_func(int index, int pci_func)
{
	struct device *dev;
	unsigned int new_devfn;

	dev = rpc.ports[index];

	/* Set the new PCI function field for this Root Port. */
	rpc.new_rpfn &= ~RPFN_FNMASK(index);
	rpc.new_rpfn |= RPFN_FNSET(index, pci_func);

	/* Determine the new devfn for this port */
	new_devfn = PCI_DEVFN(PCH_PCIE_DEV_SLOT, pci_func);

	if (dev && dev->path.pci.devfn != new_devfn) {
		printk(BIOS_DEBUG,
		       "PCH: PCIe map %02x.%1x -> %02x.%1x\n",
		       PCI_SLOT(dev->path.pci.devfn),
		       PCI_FUNC(dev->path.pci.devfn),
		       PCI_SLOT(new_devfn), PCI_FUNC(new_devfn));

		dev->path.pci.devfn = new_devfn;
	}
}

static void pcie_enable_clock_gating(void)
{
	int i;
	int is_lp;
	int enabled_ports;

	is_lp = pch_is_lp();
	enabled_ports = 0;

	for (i = 0; i < rpc.num_ports; i++) {
		struct device *dev;
		int rp;

		dev = rpc.ports[i];
		if (!dev)
			continue;

		rp = root_port_number(dev);

		if (!is_rp_enabled(rp)) {

			/* Configure shared resource clock gating. */
			if (rp == 1 || rp == 5 || (rp == 6 && is_lp))
				pci_or_config8(dev, 0xe1, 0x3c);

			if (!is_lp) {
				if (rp == 1 && !is_rp_enabled(2) &&
				    !is_rp_enabled(3) && !is_rp_enabled(4)) {
					pci_or_config8(dev, 0xe2, 1);
					pci_or_config8(dev, 0xe1, 1 << 7);
				}
				if (rp == 5 && !is_rp_enabled(6) &&
				    !is_rp_enabled(7) && !is_rp_enabled(8)) {
					pci_or_config8(dev, 0xe2, 1);
					pci_or_config8(dev, 0xe1, 1 << 7);
				}
				continue;
			}

			pci_or_config8(dev, 0xe2, 3 << 4);
			pci_or_config32(dev, 0x420, 1 << 31);

			/* Per-Port CLKREQ# handling. */
			if (is_lp && gpio_is_native(18 + rp - 1))
				pci_or_config32(dev, 0x420, 3 << 29);

			/* Enable static clock gating. */
			if (rp == 1 && !is_rp_enabled(2) &&
			    !is_rp_enabled(3) && !is_rp_enabled(4)) {
				pci_or_config8(dev, 0xe2, 1);
				pci_or_config8(dev, 0xe1, 1 << 7);
			} else if (rp == 5 || rp == 6) {
				pci_or_config8(dev, 0xe2, 1);
				pci_or_config8(dev, 0xe1, 1 << 7);
			}
			continue;
		}

		enabled_ports++;

		/* Enable dynamic clock gating. */
		pci_or_config8(dev, 0xe1, 0x03);

		if (is_lp) {
			pci_or_config8(dev, 0xe2, 1 << 6);
			pci_update_config8(dev, 0xe8, ~(3 << 2), (2 << 2));
		}

		/* Update PECR1 register. */
		pci_or_config8(dev, 0xe8, 1);

		/* FIXME: Are we supposed to update this register with a constant boolean? */
		pci_update_config8(dev, 0x324, ~(1 << 5), (1 < 5));

		/* Per-Port CLKREQ# handling. */
		if (is_lp && gpio_is_native(18 + rp - 1))
			pci_or_config32(dev, 0x420, 3 << 29);

		/* Configure shared resource clock gating. */
		if (rp == 1 || rp == 5 || (rp == 6 && is_lp))
			pci_or_config8(dev, 0xe1, 0x3c);
	}

	if (!enabled_ports && is_lp && rpc.ports[0])
		pci_or_config8(rpc.ports[0], 0xe1, 1 << 6);
}

static void root_port_commit_config(void)
{
	int i;

	/* If the first root port is disabled the coalesce ports. */
	if (!is_rp_enabled(1))
		rpc.coalesce = 1;

	/* Perform clock gating configuration. */
	pcie_enable_clock_gating();

	for (i = 0; i < rpc.num_ports; i++) {
		struct device *dev;

		dev = rpc.ports[i];

		if (dev == NULL) {
			printk(BIOS_ERR, "Root Port %d device is NULL?\n", i+1);
			continue;
		}

		if (dev->enabled)
			continue;

		printk(BIOS_DEBUG, "%s: Disabling device\n",  dev_path(dev));

		/* Ensure memory, io, and bus master are all disabled */
		pci_and_config16(dev, PCI_COMMAND,
				~(PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY | PCI_COMMAND_IO));

		/* Disable this device if possible */
		pch_disable_devfn(dev);
	}

	if (rpc.coalesce) {
		int current_func;

		/* For all Root Ports N enabled ports get assigned the lower
		 * PCI function number. The disabled ones get upper PCI
		 * function numbers. */
		current_func = 0;
		for (i = 0; i < rpc.num_ports; i++) {
			if (!is_rp_enabled(i + 1))
				continue;
			pch_pcie_device_set_func(i, current_func);
			current_func++;
		}

		/* Allocate the disabled devices' PCI function number. */
		for (i = 0; i < rpc.num_ports; i++) {
			if (is_rp_enabled(i + 1))
				continue;
			pch_pcie_device_set_func(i, current_func);
			current_func++;
		}
	}

	printk(BIOS_SPEW, "PCH: RPFN 0x%08x -> 0x%08x\n",
	       rpc.orig_rpfn, rpc.new_rpfn);
	RCBA32(RPFN) = rpc.new_rpfn;
}

static void root_port_mark_disable(struct device *dev)
{
	/* Mark device as disabled. */
	dev->enabled = 0;
	/* Mark device to be hidden. */
	rpc.new_rpfn |= RPFN_HIDE(PCI_FUNC(dev->path.pci.devfn));
}

static void root_port_check_disable(struct device *dev)
{
	int rp;
	int is_lp;

	/* Device already disabled. */
	if (!dev->enabled) {
		root_port_mark_disable(dev);
		return;
	}

	rp = root_port_number(dev);

	/* Is the GbE port mapped to this Root Port? */
	if (rp == rpc.gbe_port) {
		root_port_mark_disable(dev);
		return;
	}

	is_lp = pch_is_lp();

	/* Check Root Port Configuration. */
	switch (rp) {
		case 2:
			/* Root Port 2 is disabled for all lane configurations
			 * but config 00b (4x1 links). */
			if ((rpc.strpfusecfg1 >> 14) & 0x3) {
				root_port_mark_disable(dev);
				return;
			}
			break;
		case 3:
			/* Root Port 3 is disabled in config 11b (1x4 links). */
			if (((rpc.strpfusecfg1 >> 14) & 0x3) == 0x3) {
				root_port_mark_disable(dev);
				return;
			}
			break;
		case 4:
			/* Root Port 4 is disabled in configs 11b (1x4 links)
			 * and 10b (2x2 links). */
			if ((rpc.strpfusecfg1 >> 14) & 0x2) {
				root_port_mark_disable(dev);
				return;
			}
			break;
		case 6:
			if (is_lp)
				break;
			/* Root Port 6 is disabled for all lane configurations
			 * but config 00b (4x1 links). */
			if ((rpc.strpfusecfg2 >> 14) & 0x3) {
				root_port_mark_disable(dev);
				return;
			}
			break;
		case 7:
			if (is_lp)
				break;
			/* Root Port 7 is disabled in config 11b (1x4 links). */
			if (((rpc.strpfusecfg2 >> 14) & 0x3) == 0x3) {
				root_port_mark_disable(dev);
				return;
			}
			break;
		case 8:
			if (is_lp)
				break;
			/* Root Port 8 is disabled in configs 11b (1x4 links)
			 * and 10b (2x2 links). */
			if ((rpc.strpfusecfg2 >> 14) & 0x2) {
				root_port_mark_disable(dev);
				return;
			}
			break;
	}

	/* Check Pin Ownership. */
	if (is_lp) {
		switch (rp) {
		case 1:
			/* Bit 0 is Root Port 1 ownership. */
			if ((rpc.pin_ownership & 0x1) == 0) {
				root_port_mark_disable(dev);
				return;
			}
			break;
		case 2:
			/* Bit 2 is Root Port 2 ownership. */
			if ((rpc.pin_ownership & 0x4) == 0) {
				root_port_mark_disable(dev);
				return;
			}
			break;
		case 6:
			/* Bits 7:4 are Root Port 6 pin-lane ownership. */
			if ((rpc.pin_ownership & 0xf0) == 0) {
				root_port_mark_disable(dev);
				return;
			}
			break;
		}
	} else {
		switch (rp) {
		case 1:
			/* Bits 4 and 0 are Root Port 1 ownership. */
			if ((rpc.pin_ownership & 0x11) == 0) {
				root_port_mark_disable(dev);
				return;
			}
			break;
		case 2:
			/* Bits 5 and 2 are Root Port 2 ownership. */
			if ((rpc.pin_ownership & 0x24) == 0) {
				root_port_mark_disable(dev);
				return;
			}
			break;
		}
	}
}

static void pcie_add_0x0202000_iobp(u32 reg)
{
	u32 reg32;

	reg32 = pch_iobp_read(reg);
	reg32 += (0x2 << 16) | (0x2 << 8);
	pch_iobp_write(reg, reg32);
}

static void pch_pcie_early(struct device *dev)
{
	int rp;
	int do_aspm;
	int is_lp;
	struct southbridge_intel_lynxpoint_config *config = dev->chip_info;

	rp = root_port_number(dev);
	do_aspm = 0;
	is_lp = pch_is_lp();

	if (is_lp) {
		switch (rp) {
		case 1:
		case 2:
		case 3:
		case 4:
			/* Bits 31:28 of b0d28f0 0x32c register correspnd to
			 * Root Ports 4:1. */
			do_aspm = !!(rpc.b0d28f0_32c & (1 << (28 + rp - 1)));
			break;
		case 5:
			/* Bit 28 of b0d28f4 0x32c register correspnd to
			 * Root Ports 4:1. */
			do_aspm = !!(rpc.b0d28f4_32c & (1 << 28));
			break;
		case 6:
			/* Bit 28 of b0d28f5 0x32c register correspnd to
			 * Root Ports 4:1. */
			do_aspm = !!(rpc.b0d28f5_32c & (1 << 28));
			break;
		}
	} else {
		switch (rp) {
		case 1:
		case 2:
		case 3:
		case 4:
			/* Bits 31:28 of b0d28f0 0x32c register correspnd to
			 * Root Ports 4:1. */
			do_aspm = !!(rpc.b0d28f0_32c & (1 << (28 + rp - 1)));
			break;
		case 5:
		case 6:
		case 7:
		case 8:
			/* Bit 31:28 of b0d28f4 0x32c register correspnd to
			 * Root Ports 8:5. */
			do_aspm = !!(rpc.b0d28f4_32c & (1 << (28 + rp - 5)));
			break;
		}
	}

	/* Allow ASPM to be forced on in devicetree */
	if (config && (config->pcie_port_force_aspm & (1 << (rp - 1))))
		do_aspm = 1;

	printk(BIOS_DEBUG, "PCIe Root Port %d ASPM is %sabled\n",
	       rp, do_aspm ? "en" : "dis");

	if (do_aspm) {
		/* Set ASPM bits in MPC2 register. */
		pci_update_config32(dev, 0xd4, ~(0x3 << 2), (1 << 4) | (0x2 << 2));

		/* Set unique clock exit latency in MPC register. */
		pci_update_config32(dev, 0xd8, ~(0x7 << 18), (0x7 << 18));

		/* Set L1 exit latency in LCAP register. */
		pci_update_config32(dev, 0x4c, ~(0x7 << 15), (0x4 << 15));

		if (is_lp) {
			switch (rp) {
			case 1:
				pcie_add_0x0202000_iobp(0xe9002440);
				break;
			case 2:
				pcie_add_0x0202000_iobp(0xe9002640);
				break;
			case 3:
				pcie_add_0x0202000_iobp(0xe9000840);
				break;
			case 4:
				pcie_add_0x0202000_iobp(0xe9000a40);
				break;
			case 5:
				pcie_add_0x0202000_iobp(0xe9000c40);
				pcie_add_0x0202000_iobp(0xe9000e40);
				pcie_add_0x0202000_iobp(0xe9001040);
				pcie_add_0x0202000_iobp(0xe9001240);
				break;
			case 6:
				/* Update IOBP based on lane ownership. */
				if (rpc.pin_ownership & (1 << 4))
					pcie_add_0x0202000_iobp(0xea002040);
				if (rpc.pin_ownership & (1 << 5))
					pcie_add_0x0202000_iobp(0xea002240);
				if (rpc.pin_ownership & (1 << 6))
					pcie_add_0x0202000_iobp(0xea002440);
				if (rpc.pin_ownership & (1 << 7))
					pcie_add_0x0202000_iobp(0xea002640);
				break;
			}
		} else {
			switch (rp) {
			case 1:
				if ((rpc.pin_ownership & 0x3) == 1)
					pcie_add_0x0202000_iobp(0xe9002e40);
				else
					pcie_add_0x0202000_iobp(0xea002040);
				break;
			case 2:
				if ((rpc.pin_ownership & 0xc) == 0x4)
					pcie_add_0x0202000_iobp(0xe9002c40);
				else
					pcie_add_0x0202000_iobp(0xea002240);
				break;
			case 3:
				pcie_add_0x0202000_iobp(0xe9002a40);
				break;
			case 4:
				pcie_add_0x0202000_iobp(0xe9002840);
				break;
			case 5:
				pcie_add_0x0202000_iobp(0xe9002640);
				break;
			case 6:
				pcie_add_0x0202000_iobp(0xe9002440);
				break;
			case 7:
				pcie_add_0x0202000_iobp(0xe9002240);
				break;
			case 8:
				pcie_add_0x0202000_iobp(0xe9002040);
				break;
			}
		}

		pci_and_config32(dev, 0x338, ~(1 << 26));
	}

	/* Enable LTR in Root Port. */
	pci_or_config32(dev, 0x64, 1 << 11);
	pci_update_config32(dev, 0x68, ~(1 << 10), (1 << 10));

	pci_update_config32(dev, 0x318, ~(0xffffUL << 16), (0x1414UL << 16));

	/* Set L1 exit latency in LCAP register. */
	if (!do_aspm && (pci_read_config8(dev, 0xf5) & 0x1))
		pci_update_config32(dev, 0x4c, ~(0x7 << 15), (0x4 << 15));
	else
		pci_update_config32(dev, 0x4c, ~(0x7 << 15), (0x2 << 15));

	pci_update_config32(dev, 0x314, 0, 0x743a361b);

	/* Set Common Clock Exit Latency in MPC register. */
	pci_update_config32(dev, 0xd8, ~(0x7 << 15), (0x3 << 15));

	pci_update_config32(dev, 0x33c, ~0x00ffffff, 0x854c74);

	/* Set Invalid Recieve Range Check Enable in MPC register. */
	pci_or_config32(dev, 0xd8, 1 << 25);

	pci_and_config8(dev, 0xf5, 0x3f);

	if (rp == 1 || rp == 5 || (is_lp && rp == 6))
		pci_and_config8(dev, 0xf7, ~0x0c);

	/* Set EOI forwarding disable. */
	pci_or_config32(dev, 0xd4, 1 << 1);

	/* Set something involving advanced error reporting. */
	pci_update_config32(dev, 0x100, ~((1 << 20) - 1), 0x10001);

	if (is_lp)
		pci_or_config32(dev, 0x100, 1 << 29);

	/* Read and write back write-once capability registers. */
	pci_update_config32(dev, 0x34, ~0, 0);
	pci_update_config32(dev, 0x40, ~0, 0);
	pci_update_config32(dev, 0x80, ~0, 0);
	pci_update_config32(dev, 0x90, ~0, 0);
}

static void pci_init(struct device *dev)
{
	printk(BIOS_DEBUG, "Initializing PCH PCIe bridge.\n");

	/* Enable SERR */
	pci_or_config16(dev, PCI_COMMAND, PCI_COMMAND_SERR);

	/* Enable Bus Master */
	pci_or_config16(dev, PCI_COMMAND, PCI_COMMAND_MASTER);

	/* Set Cache Line Size to 0x10 */
	// This has no effect but the OS might expect it
	pci_write_config8(dev, 0x0c, 0x10);

	pci_and_config16(dev, PCI_BRIDGE_CONTROL, ~PCI_BRIDGE_CTL_PARITY);

	/* Clear errors in status registers */
	pci_update_config16(dev, 0x06, ~0, 0);
	pci_update_config16(dev, 0x1e, ~0, 0);
}

static void pch_pcie_enable(struct device *dev)
{
	/* Add this device to the root port config structure. */
	root_port_init_config(dev);

	/* Check to see if this Root Port should be disabled. */
	root_port_check_disable(dev);

	/* Power Management init before enumeration */
	if (dev->enabled)
		pch_pcie_early(dev);

	/*
	 * When processing the last PCIe root port we can now
	 * update the Root Port Function Number and Hide register.
	 */
	if (root_port_is_last(dev))
		root_port_commit_config();
}

static struct device_operations device_ops = {
	.read_resources		= pci_bus_read_resources,
	.set_resources		= pci_dev_set_resources,
	.enable_resources	= pci_bus_enable_resources,
	.init			= pci_init,
	.enable			= pch_pcie_enable,
	.scan_bus		= pciexp_scan_bridge,
	.ops_pci		= &pci_dev_ops_pci,
};

static const unsigned short pci_device_ids[] = {
	/* Lynxpoint Mobile */
	0x8c10, 0x8c12, 0x8c14, 0x8c16, 0x8c18, 0x8c1a, 0x8c1c, 0x8c1e,
	/* Lynxpoint Low Power */
	0x9c10, 0x9c12, 0x9c14, 0x9c16, 0x9c18, 0x9c1a,
	0
};

static const struct pci_driver pch_pcie __pci_driver = {
	.ops	 = &device_ops,
	.vendor	 = PCI_VENDOR_ID_INTEL,
	.devices = pci_device_ids,
};