/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2005-2007 Cavium Networks
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/delay.h>

#include <asm/time.h>

#include <asm/octeon/octeon.h>
#include <asm/octeon/cvmx-npi-defs.h>
#include <asm/octeon/cvmx-pci-defs.h>

#include "pci-common.h"

#define USE_OCTEON_INTERNAL_ARBITER

/*
 * Octeon's PCI controller uses did=3, subdid=2 for PCI IO
 * addresses. Use PCI endian swapping 1 so no address swapping is
 * necessary. The Linux io routines will endian swap the data.
 */
#define OCTEON_PCI_IOSPACE_BASE     0x80011a0400000000ull
#define OCTEON_PCI_IOSPACE_SIZE     (1ull<<32)

/* Octeon't PCI controller uses did=3, subdid=3 for PCI memory. */
#define OCTEON_PCI_MEMSPACE_OFFSET  (0x00011b0000000000ull)

/**
 * This is the bit decoding used for the Octeon PCI controller addresses
 */
union octeon_pci_address {
	uint64_t u64;
	struct {
		uint64_t upper:2;
		uint64_t reserved:13;
		uint64_t io:1;
		uint64_t did:5;
		uint64_t subdid:3;
		uint64_t reserved2:4;
		uint64_t endian_swap:2;
		uint64_t reserved3:10;
		uint64_t bus:8;
		uint64_t dev:5;
		uint64_t func:3;
		uint64_t reg:8;
	} s;
};

/**
 * Return the mapping of PCI device number to IRQ line. Each
 * character in the return string represents the interrupt
 * line for the device at that position. Device 1 maps to the
 * first character, etc. The characters A-D are used for PCI
 * interrupts.
 *
 * Returns PCI interrupt mapping
 */
const char *octeon_get_pci_interrupts(void)
{
	/*
	 * Returning an empty string causes the interrupts to be
	 * routed based on the PCI specification. From the PCI spec:
	 *
	 * INTA# of Device Number 0 is connected to IRQW on the system
	 * board.  (Device Number has no significance regarding being
	 * located on the system board or in a connector.) INTA# of
	 * Device Number 1 is connected to IRQX on the system
	 * board. INTA# of Device Number 2 is connected to IRQY on the
	 * system board. INTA# of Device Number 3 is connected to IRQZ
	 * on the system board. The table below describes how each
	 * agent's INTx# lines are connected to the system board
	 * interrupt lines. The following equation can be used to
	 * determine to which INTx# signal on the system board a given
	 * device's INTx# line(s) is connected.
	 *
	 * MB = (D + I) MOD 4 MB = System board Interrupt (IRQW = 0,
	 * IRQX = 1, IRQY = 2, and IRQZ = 3) D = Device Number I =
	 * Interrupt Number (INTA# = 0, INTB# = 1, INTC# = 2, and
	 * INTD# = 3)
	 */
	switch (octeon_bootinfo->board_type) {
	case CVMX_BOARD_TYPE_NAO38:
		/* This is really the NAC38 */
		return "AAAAADABAAAAAAAAAAAAAAAAAAAAAAAA";
	case CVMX_BOARD_TYPE_THUNDER:
		return "";
	case CVMX_BOARD_TYPE_EBH3000:
		return "";
	case CVMX_BOARD_TYPE_EBH3100:
	case CVMX_BOARD_TYPE_CN3010_EVB_HS5:
	case CVMX_BOARD_TYPE_CN3005_EVB_HS5:
		return "AAABAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
	case CVMX_BOARD_TYPE_BBGW_REF:
		return "AABCD";
	default:
		return "";
	}
}

/**
 * Map a PCI device to the appropriate interrupt line
 *
 * @dev:    The Linux PCI device structure for the device to map
 * @slot:   The slot number for this device on __BUS 0__. Linux
 *               enumerates through all the bridges and figures out the
 *               slot on Bus 0 where this device eventually hooks to.
 * @pin:    The PCI interrupt pin read from the device, then swizzled
 *               as it goes through each bridge.
 * Returns Interrupt number for the device
 */
int __init octeon_pci_pcibios_map_irq(const struct pci_dev *dev,
				      u8 slot, u8 pin)
{
	int irq_num;
	const char *interrupts;
	int dev_num;

	/* Get the board specific interrupt mapping */
	interrupts = octeon_get_pci_interrupts();

	dev_num = dev->devfn >> 3;
	if (dev_num < strlen(interrupts))
		irq_num = ((interrupts[dev_num] - 'A' + pin - 1) & 3) +
			OCTEON_IRQ_PCI_INT0;
	else
		irq_num = ((slot + pin - 3) & 3) + OCTEON_IRQ_PCI_INT0;
	return irq_num;
}


/**
 * Read a value from configuration space
 *
 */
static int octeon_read_config(struct pci_bus *bus, unsigned int devfn,
			      int reg, int size, u32 *val)
{
	union octeon_pci_address pci_addr;

	pci_addr.u64 = 0;
	pci_addr.s.upper = 2;
	pci_addr.s.io = 1;
	pci_addr.s.did = 3;
	pci_addr.s.subdid = 1;
	pci_addr.s.endian_swap = 1;
	pci_addr.s.bus = bus->number;
	pci_addr.s.dev = devfn >> 3;
	pci_addr.s.func = devfn & 0x7;
	pci_addr.s.reg = reg;

#if PCI_CONFIG_SPACE_DELAY
	udelay(PCI_CONFIG_SPACE_DELAY);
#endif
	switch (size) {
	case 4:
		*val = le32_to_cpu(cvmx_read64_uint32(pci_addr.u64));
		return PCIBIOS_SUCCESSFUL;
	case 2:
		*val = le16_to_cpu(cvmx_read64_uint16(pci_addr.u64));
		return PCIBIOS_SUCCESSFUL;
	case 1:
		*val = cvmx_read64_uint8(pci_addr.u64);
		return PCIBIOS_SUCCESSFUL;
	}
	return PCIBIOS_FUNC_NOT_SUPPORTED;
}


/**
 * Write a value to PCI configuration space
 *
 * @bus:
 * @devfn:
 * @reg:
 * @size:
 * @val:
 * Returns
 */
static int octeon_write_config(struct pci_bus *bus, unsigned int devfn,
			       int reg, int size, u32 val)
{
	union octeon_pci_address pci_addr;

	pci_addr.u64 = 0;
	pci_addr.s.upper = 2;
	pci_addr.s.io = 1;
	pci_addr.s.did = 3;
	pci_addr.s.subdid = 1;
	pci_addr.s.endian_swap = 1;
	pci_addr.s.bus = bus->number;
	pci_addr.s.dev = devfn >> 3;
	pci_addr.s.func = devfn & 0x7;
	pci_addr.s.reg = reg;

#if PCI_CONFIG_SPACE_DELAY
	udelay(PCI_CONFIG_SPACE_DELAY);
#endif
	switch (size) {
	case 4:
		cvmx_write64_uint32(pci_addr.u64, cpu_to_le32(val));
		return PCIBIOS_SUCCESSFUL;
	case 2:
		cvmx_write64_uint16(pci_addr.u64, cpu_to_le16(val));
		return PCIBIOS_SUCCESSFUL;
	case 1:
		cvmx_write64_uint8(pci_addr.u64, val);
		return PCIBIOS_SUCCESSFUL;
	}
	return PCIBIOS_FUNC_NOT_SUPPORTED;
}


static struct pci_ops octeon_pci_ops = {
	octeon_read_config,
	octeon_write_config,
};

static struct resource octeon_pci_mem_resource = {
	.start = 0,
	.end = 0,
	.name = "Octeon PCI MEM",
	.flags = IORESOURCE_MEM,
};

/*
 * PCI ports must be above 16KB so the ISA bus filtering in the PCI-X to PCI
 * bridge
 */
static struct resource octeon_pci_io_resource = {
	.start = 0x4000,
	.end = OCTEON_PCI_IOSPACE_SIZE - 1,
	.name = "Octeon PCI IO",
	.flags = IORESOURCE_IO,
};

static struct pci_controller octeon_pci_controller = {
	.pci_ops = &octeon_pci_ops,
	.mem_resource = &octeon_pci_mem_resource,
	.mem_offset = OCTEON_PCI_MEMSPACE_OFFSET,
	.io_resource = &octeon_pci_io_resource,
	.io_offset = 0,
	.io_map_base = OCTEON_PCI_IOSPACE_BASE,
};


/**
 * Low level initialize the Octeon PCI controller
 *
 * Returns
 */
static void octeon_pci_initialize(void)
{
	union cvmx_pci_cfg01 cfg01;
	union cvmx_npi_ctl_status ctl_status;
	union cvmx_pci_ctl_status_2 ctl_status_2;
	union cvmx_pci_cfg19 cfg19;
	union cvmx_pci_cfg16 cfg16;
	union cvmx_pci_cfg22 cfg22;
	union cvmx_pci_cfg56 cfg56;

	/* Reset the PCI Bus */
	cvmx_write_csr(CVMX_CIU_SOFT_PRST, 0x1);
	cvmx_read_csr(CVMX_CIU_SOFT_PRST);

	udelay(2000);		/* Hold PCI reset for 2 ms */

	ctl_status.u64 = 0;	/* cvmx_read_csr(CVMX_NPI_CTL_STATUS); */
	ctl_status.s.max_word = 1;
	ctl_status.s.timer = 1;
	cvmx_write_csr(CVMX_NPI_CTL_STATUS, ctl_status.u64);

	/* Deassert PCI reset and advertize PCX Host Mode Device Capability
	   (64b) */
	cvmx_write_csr(CVMX_CIU_SOFT_PRST, 0x4);
	cvmx_read_csr(CVMX_CIU_SOFT_PRST);

	udelay(2000);		/* Wait 2 ms after deasserting PCI reset */

	ctl_status_2.u32 = 0;
	ctl_status_2.s.tsr_hwm = 1;	/* Initializes to 0.  Must be set
					   before any PCI reads. */
	ctl_status_2.s.bar2pres = 1;	/* Enable BAR2 */
	ctl_status_2.s.bar2_enb = 1;
	ctl_status_2.s.bar2_cax = 1;	/* Don't use L2 */
	ctl_status_2.s.bar2_esx = 1;
	ctl_status_2.s.pmo_amod = 1;	/* Round robin priority */
	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_BIG) {
		/* BAR1 hole */
		ctl_status_2.s.bb1_hole = OCTEON_PCI_BAR1_HOLE_BITS;
		ctl_status_2.s.bb1_siz = 1;  /* BAR1 is 2GB */
		ctl_status_2.s.bb_ca = 1;    /* Don't use L2 with big bars */
		ctl_status_2.s.bb_es = 1;    /* Big bar in byte swap mode */
		ctl_status_2.s.bb1 = 1;      /* BAR1 is big */
		ctl_status_2.s.bb0 = 1;      /* BAR0 is big */
	}

	octeon_npi_write32(CVMX_NPI_PCI_CTL_STATUS_2, ctl_status_2.u32);
	udelay(2000);		/* Wait 2 ms before doing PCI reads */

	ctl_status_2.u32 = octeon_npi_read32(CVMX_NPI_PCI_CTL_STATUS_2);
	pr_notice("PCI Status: %s %s-bit\n",
		  ctl_status_2.s.ap_pcix ? "PCI-X" : "PCI",
		  ctl_status_2.s.ap_64ad ? "64" : "32");

	if (OCTEON_IS_MODEL(OCTEON_CN58XX) || OCTEON_IS_MODEL(OCTEON_CN50XX)) {
		union cvmx_pci_cnt_reg cnt_reg_start;
		union cvmx_pci_cnt_reg cnt_reg_end;
		unsigned long cycles, pci_clock;

		cnt_reg_start.u64 = cvmx_read_csr(CVMX_NPI_PCI_CNT_REG);
		cycles = read_c0_cvmcount();
		udelay(1000);
		cnt_reg_end.u64 = cvmx_read_csr(CVMX_NPI_PCI_CNT_REG);
		cycles = read_c0_cvmcount() - cycles;
		pci_clock = (cnt_reg_end.s.pcicnt - cnt_reg_start.s.pcicnt) /
			    (cycles / (mips_hpt_frequency / 1000000));
		pr_notice("PCI Clock: %lu MHz\n", pci_clock);
	}

	/*
	 * TDOMC must be set to one in PCI mode. TDOMC should be set to 4
	 * in PCI-X mode to allow four oustanding splits. Otherwise,
	 * should not change from its reset value. Don't write PCI_CFG19
	 * in PCI mode (0x82000001 reset value), write it to 0x82000004
	 * after PCI-X mode is known. MRBCI,MDWE,MDRE -> must be zero.
	 * MRBCM -> must be one.
	 */
	if (ctl_status_2.s.ap_pcix) {
		cfg19.u32 = 0;
		/*
		 * Target Delayed/Split request outstanding maximum
		 * count. [1..31] and 0=32.  NOTE: If the user
		 * programs these bits beyond the Designed Maximum
		 * outstanding count, then the designed maximum table
		 * depth will be used instead.  No additional
		 * Deferred/Split transactions will be accepted if
		 * this outstanding maximum count is
		 * reached. Furthermore, no additional deferred/split
		 * transactions will be accepted if the I/O delay/ I/O
		 * Split Request outstanding maximum is reached.
		 */
		cfg19.s.tdomc = 4;
		/*
		 * Master Deferred Read Request Outstanding Max Count
		 * (PCI only).  CR4C[26:24] Max SAC cycles MAX DAC
		 * cycles 000 8 4 001 1 0 010 2 1 011 3 1 100 4 2 101
		 * 5 2 110 6 3 111 7 3 For example, if these bits are
		 * programmed to 100, the core can support 2 DAC
		 * cycles, 4 SAC cycles or a combination of 1 DAC and
		 * 2 SAC cycles. NOTE: For the PCI-X maximum
		 * outstanding split transactions, refer to
		 * CRE0[22:20].
		 */
		cfg19.s.mdrrmc = 2;
		/*
		 * Master Request (Memory Read) Byte Count/Byte Enable
		 * select. 0 = Byte Enables valid. In PCI mode, a
		 * burst transaction cannot be performed using Memory
		 * Read command=4?h6. 1 = DWORD Byte Count valid
		 * (default). In PCI Mode, the memory read byte
		 * enables are automatically generated by the
		 * core. Note: N3 Master Request transaction sizes are
		 * always determined through the
		 * am_attr[<35:32>|<7:0>] field.
		 */
		cfg19.s.mrbcm = 1;
		octeon_npi_write32(CVMX_NPI_PCI_CFG19, cfg19.u32);
	}


	cfg01.u32 = 0;
	cfg01.s.msae = 1;	/* Memory Space Access Enable */
	cfg01.s.me = 1;		/* Master Enable */
	cfg01.s.pee = 1;	/* PERR# Enable */
	cfg01.s.see = 1;	/* System Error Enable */
	cfg01.s.fbbe = 1;	/* Fast Back to Back Transaction Enable */

	octeon_npi_write32(CVMX_NPI_PCI_CFG01, cfg01.u32);

#ifdef USE_OCTEON_INTERNAL_ARBITER
	/*
	 * When OCTEON is a PCI host, most systems will use OCTEON's
	 * internal arbiter, so must enable it before any PCI/PCI-X
	 * traffic can occur.
	 */
	{
		union cvmx_npi_pci_int_arb_cfg pci_int_arb_cfg;

		pci_int_arb_cfg.u64 = 0;
		pci_int_arb_cfg.s.en = 1;	/* Internal arbiter enable */
		cvmx_write_csr(CVMX_NPI_PCI_INT_ARB_CFG, pci_int_arb_cfg.u64);
	}
#endif				/* USE_OCTEON_INTERNAL_ARBITER */

	/*
	 * Preferrably written to 1 to set MLTD. [RDSATI,TRTAE,
	 * TWTAE,TMAE,DPPMR -> must be zero. TILT -> must not be set to
	 * 1..7.
	 */
	cfg16.u32 = 0;
	cfg16.s.mltd = 1;	/* Master Latency Timer Disable */
	octeon_npi_write32(CVMX_NPI_PCI_CFG16, cfg16.u32);

	/*
	 * Should be written to 0x4ff00. MTTV -> must be zero.
	 * FLUSH -> must be 1. MRV -> should be 0xFF.
	 */
	cfg22.u32 = 0;
	/* Master Retry Value [1..255] and 0=infinite */
	cfg22.s.mrv = 0xff;
	/*
	 * AM_DO_FLUSH_I control NOTE: This bit MUST BE ONE for proper
	 * N3K operation.
	 */
	cfg22.s.flush = 1;
	octeon_npi_write32(CVMX_NPI_PCI_CFG22, cfg22.u32);

	/*
	 * MOST Indicates the maximum number of outstanding splits (in -1
	 * notation) when OCTEON is in PCI-X mode.  PCI-X performance is
	 * affected by the MOST selection.  Should generally be written
	 * with one of 0x3be807, 0x2be807, 0x1be807, or 0x0be807,
	 * depending on the desired MOST of 3, 2, 1, or 0, respectively.
	 */
	cfg56.u32 = 0;
	cfg56.s.pxcid = 7;	/* RO - PCI-X Capability ID */
	cfg56.s.ncp = 0xe8;	/* RO - Next Capability Pointer */
	cfg56.s.dpere = 1;	/* Data Parity Error Recovery Enable */
	cfg56.s.roe = 1;	/* Relaxed Ordering Enable */
	cfg56.s.mmbc = 1;	/* Maximum Memory Byte Count
				   [0=512B,1=1024B,2=2048B,3=4096B] */
	cfg56.s.most = 3;	/* Maximum outstanding Split transactions [0=1
				   .. 7=32] */

	octeon_npi_write32(CVMX_NPI_PCI_CFG56, cfg56.u32);

	/*
	 * Affects PCI performance when OCTEON services reads to its
	 * BAR1/BAR2. Refer to Section 10.6.1.  The recommended values are
	 * 0x22, 0x33, and 0x33 for PCI_READ_CMD_6, PCI_READ_CMD_C, and
	 * PCI_READ_CMD_E, respectively. Unfortunately due to errata DDR-700,
	 * these values need to be changed so they won't possibly prefetch off
	 * of the end of memory if PCI is DMAing a buffer at the end of
	 * memory. Note that these values differ from their reset values.
	 */
	octeon_npi_write32(CVMX_NPI_PCI_READ_CMD_6, 0x21);
	octeon_npi_write32(CVMX_NPI_PCI_READ_CMD_C, 0x31);
	octeon_npi_write32(CVMX_NPI_PCI_READ_CMD_E, 0x31);
}


/**
 * Initialize the Octeon PCI controller
 *
 * Returns
 */
static int __init octeon_pci_setup(void)
{
	union cvmx_npi_mem_access_subidx mem_access;
	int index;

	/* Only these chips have PCI */
	if (octeon_has_feature(OCTEON_FEATURE_PCIE))
		return 0;

	/* Point pcibios_map_irq() to the PCI version of it */
	octeon_pcibios_map_irq = octeon_pci_pcibios_map_irq;

	/* Only use the big bars on chips that support it */
	if (OCTEON_IS_MODEL(OCTEON_CN31XX) ||
	    OCTEON_IS_MODEL(OCTEON_CN38XX_PASS2) ||
	    OCTEON_IS_MODEL(OCTEON_CN38XX_PASS1))
		octeon_dma_bar_type = OCTEON_DMA_BAR_TYPE_SMALL;
	else
		octeon_dma_bar_type = OCTEON_DMA_BAR_TYPE_BIG;

	/* PCI I/O and PCI MEM values */
	set_io_port_base(OCTEON_PCI_IOSPACE_BASE);
	ioport_resource.start = 0;
	ioport_resource.end = OCTEON_PCI_IOSPACE_SIZE - 1;
	if (!octeon_is_pci_host()) {
		pr_notice("Not in host mode, PCI Controller not initialized\n");
		return 0;
	}

	pr_notice("%s Octeon big bar support\n",
		  (octeon_dma_bar_type ==
		  OCTEON_DMA_BAR_TYPE_BIG) ? "Enabling" : "Disabling");

	octeon_pci_initialize();

	mem_access.u64 = 0;
	mem_access.s.esr = 1;	/* Endian-Swap on read. */
	mem_access.s.esw = 1;	/* Endian-Swap on write. */
	mem_access.s.nsr = 0;	/* No-Snoop on read. */
	mem_access.s.nsw = 0;	/* No-Snoop on write. */
	mem_access.s.ror = 0;	/* Relax Read on read. */
	mem_access.s.row = 0;	/* Relax Order on write. */
	mem_access.s.ba = 0;	/* PCI Address bits [63:36]. */
	cvmx_write_csr(CVMX_NPI_MEM_ACCESS_SUBID3, mem_access.u64);

	/*
	 * Remap the Octeon BAR 2 above all 32 bit devices
	 * (0x8000000000ul).  This is done here so it is remapped
	 * before the readl()'s below. We don't want BAR2 overlapping
	 * with BAR0/BAR1 during these reads.
	 */
	octeon_npi_write32(CVMX_NPI_PCI_CFG08, 0);
	octeon_npi_write32(CVMX_NPI_PCI_CFG09, 0x80);

	/* Disable the BAR1 movable mappings */
	for (index = 0; index < 32; index++)
		octeon_npi_write32(CVMX_NPI_PCI_BAR1_INDEXX(index), 0);

	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_BIG) {
		/* Remap the Octeon BAR 0 to 0-2GB */
		octeon_npi_write32(CVMX_NPI_PCI_CFG04, 0);
		octeon_npi_write32(CVMX_NPI_PCI_CFG05, 0);

		/*
		 * Remap the Octeon BAR 1 to map 2GB-4GB (minus the
		 * BAR 1 hole).
		 */
		octeon_npi_write32(CVMX_NPI_PCI_CFG06, 2ul << 30);
		octeon_npi_write32(CVMX_NPI_PCI_CFG07, 0);

		/* Devices go after BAR1 */
		octeon_pci_mem_resource.start =
			OCTEON_PCI_MEMSPACE_OFFSET + (4ul << 30) -
			(OCTEON_PCI_BAR1_HOLE_SIZE << 20);
		octeon_pci_mem_resource.end =
			octeon_pci_mem_resource.start + (1ul << 30);
	} else {
		/* Remap the Octeon BAR 0 to map 128MB-(128MB+4KB) */
		octeon_npi_write32(CVMX_NPI_PCI_CFG04, 128ul << 20);
		octeon_npi_write32(CVMX_NPI_PCI_CFG05, 0);

		/* Remap the Octeon BAR 1 to map 0-128MB */
		octeon_npi_write32(CVMX_NPI_PCI_CFG06, 0);
		octeon_npi_write32(CVMX_NPI_PCI_CFG07, 0);

		/* Devices go after BAR0 */
		octeon_pci_mem_resource.start =
			OCTEON_PCI_MEMSPACE_OFFSET + (128ul << 20) +
			(4ul << 10);
		octeon_pci_mem_resource.end =
			octeon_pci_mem_resource.start + (1ul << 30);
	}

	register_pci_controller(&octeon_pci_controller);

	/*
	 * Clear any errors that might be pending from before the bus
	 * was setup properly.
	 */
	cvmx_write_csr(CVMX_NPI_PCI_INT_SUM2, -1);
	return 0;
}

arch_initcall(octeon_pci_setup);