// SPDX-License-Identifier: GPL-2.0
/*
 * CHRP pci routines.
 */

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/pgtable.h>
#include <linux/of_address.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/hydra.h>
#include <asm/machdep.h>
#include <asm/sections.h>
#include <asm/pci-bridge.h>
#include <asm/grackle.h>
#include <asm/rtas.h>

#include "chrp.h"
#include "gg2.h"

/* LongTrail */
void __iomem *gg2_pci_config_base;

/*
 * The VLSI Golden Gate II has only 512K of PCI configuration space, so we
 * limit the bus number to 3 bits
 */

static int gg2_read_config(struct pci_bus *bus, unsigned int devfn, int off,
                           int len, u32 *val)
{
        volatile void __iomem *cfg_data;
        struct pci_controller *hose = pci_bus_to_host(bus);

        if (bus->number > 7)
                return PCIBIOS_DEVICE_NOT_FOUND;
        /*
         * Note: the caller has already checked that off is
         * suitably aligned and that len is 1, 2 or 4.
         */
        cfg_data = hose->cfg_data + ((bus->number<<16) | (devfn<<8) | off);
        switch (len) {
        case 1:
                *val =  in_8(cfg_data);
                break;
        case 2:
                *val = in_le16(cfg_data);
                break;
        default:
                *val = in_le32(cfg_data);
                break;
        }
        return PCIBIOS_SUCCESSFUL;
}

static int gg2_write_config(struct pci_bus *bus, unsigned int devfn, int off,
                            int len, u32 val)
{
        volatile void __iomem *cfg_data;
        struct pci_controller *hose = pci_bus_to_host(bus);

        if (bus->number > 7)
                return PCIBIOS_DEVICE_NOT_FOUND;
        /*
         * Note: the caller has already checked that off is
         * suitably aligned and that len is 1, 2 or 4.
         */
        cfg_data = hose->cfg_data + ((bus->number<<16) | (devfn<<8) | off);
        switch (len) {
        case 1:
                out_8(cfg_data, val);
                break;
        case 2:
                out_le16(cfg_data, val);
                break;
        default:
                out_le32(cfg_data, val);
                break;
        }
        return PCIBIOS_SUCCESSFUL;
}

static struct pci_ops gg2_pci_ops =
{
        .read = gg2_read_config,
        .write = gg2_write_config,
};

/*
 * Access functions for PCI config space using RTAS calls.
 */
static int rtas_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
                            int len, u32 *val)
{
        struct pci_controller *hose = pci_bus_to_host(bus);
        unsigned long addr = (offset & 0xff) | ((devfn & 0xff) << 8)
                | (((bus->number - hose->first_busno) & 0xff) << 16)
                | (hose->global_number << 24);
        int ret = -1;
        int rval;

        rval = rtas_call(rtas_function_token(RTAS_FN_READ_PCI_CONFIG), 2, 2, &ret, addr, len);
        *val = ret;
        return rval? PCIBIOS_DEVICE_NOT_FOUND: PCIBIOS_SUCCESSFUL;
}

static int rtas_write_config(struct pci_bus *bus, unsigned int devfn, int offset,
                             int len, u32 val)
{
        struct pci_controller *hose = pci_bus_to_host(bus);
        unsigned long addr = (offset & 0xff) | ((devfn & 0xff) << 8)
                | (((bus->number - hose->first_busno) & 0xff) << 16)
                | (hose->global_number << 24);
        int rval;

        rval = rtas_call(rtas_function_token(RTAS_FN_WRITE_PCI_CONFIG), 3, 1, NULL,
                         addr, len, val);
        return rval? PCIBIOS_DEVICE_NOT_FOUND: PCIBIOS_SUCCESSFUL;
}

static struct pci_ops rtas_pci_ops =
{
        .read = rtas_read_config,
        .write = rtas_write_config,
};

volatile struct Hydra __iomem *Hydra = NULL;

static int __init hydra_init(void)
{
        struct device_node *np;
        struct resource r;

        np = of_find_node_by_name(NULL, "mac-io");
        if (np == NULL || of_address_to_resource(np, 0, &r)) {
                of_node_put(np);
                return 0;
        }
        of_node_put(np);
        Hydra = ioremap(r.start, resource_size(&r));
        printk("Hydra Mac I/O at %llx\n", (unsigned long long)r.start);
        printk("Hydra Feature_Control was %x",
               in_le32(&Hydra->Feature_Control));
        out_le32(&Hydra->Feature_Control, (HYDRA_FC_SCC_CELL_EN |
                                           HYDRA_FC_SCSI_CELL_EN |
                                           HYDRA_FC_SCCA_ENABLE |
                                           HYDRA_FC_SCCB_ENABLE |
                                           HYDRA_FC_ARB_BYPASS |
                                           HYDRA_FC_MPIC_ENABLE |
                                           HYDRA_FC_SLOW_SCC_PCLK |
                                           HYDRA_FC_MPIC_IS_MASTER));
        printk(", now %x\n", in_le32(&Hydra->Feature_Control));
        return 1;
}

#define PRG_CL_RESET_VALID 0x00010000

static void __init
setup_python(struct pci_controller *hose, struct device_node *dev)
{
        u32 __iomem *reg;
        u32 val;
        struct resource r;

        if (of_address_to_resource(dev, 0, &r)) {
                printk(KERN_ERR "No address for Python PCI controller\n");
                return;
        }

        /* Clear the magic go-slow bit */
        reg = ioremap(r.start + 0xf6000, 0x40);
        BUG_ON(!reg); 
        val = in_be32(&reg[12]);
        if (val & PRG_CL_RESET_VALID) {
                out_be32(&reg[12], val & ~PRG_CL_RESET_VALID);
                in_be32(&reg[12]);
        }
        iounmap(reg);

        setup_indirect_pci(hose, r.start + 0xf8000, r.start + 0xf8010, 0);
}

/* Marvell Discovery II based Pegasos 2 */
static void __init setup_peg2(struct pci_controller *hose, struct device_node *dev)
{
        struct device_node *root = of_find_node_by_path("/");
        struct device_node *rtas;

        rtas = of_find_node_by_name (root, "rtas");
        if (rtas) {
                hose->ops = &rtas_pci_ops;
                of_node_put(rtas);
        } else {
                printk ("RTAS supporting Pegasos OF not found, please upgrade"
                        " your firmware\n");
        }
        pci_add_flags(PCI_REASSIGN_ALL_BUS);
        /* keep the reference to the root node */
}

void __init
chrp_find_bridges(void)
{
        struct device_node *dev;
        const int *bus_range;
        int len, index = -1;
        struct pci_controller *hose;
        const unsigned int *dma;
        const char *model, *machine;
        int is_longtrail = 0, is_mot = 0, is_pegasos = 0;
        struct device_node *root = of_find_node_by_path("/");
        struct resource r;
        /*
         * The PCI host bridge nodes on some machines don't have
         * properties to adequately identify them, so we have to
         * look at what sort of machine this is as well.
         */
        machine = of_get_property(root, "model", NULL);
        if (machine != NULL) {
                is_longtrail = strncmp(machine, "IBM,LongTrail", 13) == 0;
                is_mot = strncmp(machine, "MOT", 3) == 0;
                if (strncmp(machine, "Pegasos2", 8) == 0)
                        is_pegasos = 2;
                else if (strncmp(machine, "Pegasos", 7) == 0)
                        is_pegasos = 1;
        }
        for_each_child_of_node(root, dev) {
                if (!of_node_is_type(dev, "pci"))
                        continue;
                ++index;
                /* The GG2 bridge on the LongTrail doesn't have an address */
                if (of_address_to_resource(dev, 0, &r) && !is_longtrail) {
                        printk(KERN_WARNING "Can't use %pOF: no address\n",
                               dev);
                        continue;
                }
                bus_range = of_get_property(dev, "bus-range", &len);
                if (bus_range == NULL || len < 2 * sizeof(int)) {
                        printk(KERN_WARNING "Can't get bus-range for %pOF\n",
                                dev);
                        continue;
                }
                if (bus_range[1] == bus_range[0])
                        printk(KERN_INFO "PCI bus %d", bus_range[0]);
                else
                        printk(KERN_INFO "PCI buses %d..%d",
                               bus_range[0], bus_range[1]);
                printk(" controlled by %pOF", dev);
                if (!is_longtrail)
                        printk(" at %llx", (unsigned long long)r.start);
                printk("\n");

                hose = pcibios_alloc_controller(dev);
                if (!hose) {
                        printk("Can't allocate PCI controller structure for %pOF\n",
                                dev);
                        continue;
                }
                hose->first_busno = hose->self_busno = bus_range[0];
                hose->last_busno = bus_range[1];

                model = of_get_property(dev, "model", NULL);
                if (model == NULL)
                        model = "<none>";
                if (strncmp(model, "IBM, Python", 11) == 0) {
                        setup_python(hose, dev);
                } else if (is_mot
                           || strncmp(model, "Motorola, Grackle", 17) == 0) {
                        setup_grackle(hose);
                } else if (is_longtrail) {
                        void __iomem *p = ioremap(GG2_PCI_CONFIG_BASE, 0x80000);
                        hose->ops = &gg2_pci_ops;
                        hose->cfg_data = p;
                        gg2_pci_config_base = p;
                } else if (is_pegasos == 1) {
                        setup_indirect_pci(hose, 0xfec00cf8, 0xfee00cfc, 0);
                } else if (is_pegasos == 2) {
                        setup_peg2(hose, dev);
                } else if (!strncmp(model, "IBM,CPC710", 10)) {
                        setup_indirect_pci(hose,
                                           r.start + 0x000f8000,
                                           r.start + 0x000f8010,
                                           0);
                        if (index == 0) {
                                dma = of_get_property(dev, "system-dma-base",
                                                        &len);
                                if (dma && len >= sizeof(*dma)) {
                                        dma = (unsigned int *)
                                                (((unsigned long)dma) +
                                                len - sizeof(*dma));
                                                pci_dram_offset = *dma;
                                }
                        }
                } else {
                        printk("No methods for %pOF (model %s), using RTAS\n",
                               dev, model);
                        hose->ops = &rtas_pci_ops;
                }

                pci_process_bridge_OF_ranges(hose, dev, index == 0);

                /* check the first bridge for a property that we can
                   use to set pci_dram_offset */
                dma = of_get_property(dev, "ibm,dma-ranges", &len);
                if (index == 0 && dma != NULL && len >= 6 * sizeof(*dma)) {
                        pci_dram_offset = dma[2] - dma[3];
                        printk("pci_dram_offset = %lx\n", pci_dram_offset);
                }
        }
        of_node_put(root);

        /*
         *  "Temporary" fixes for PCI devices.
         *  -- Geert
         */
        hydra_init();           /* Mac I/O */

        pci_create_OF_bus_map();
}

/* SL82C105 IDE Control/Status Register */
#define SL82C105_IDECSR                0x40

/* Fixup for Winbond ATA quirk, required for briq mostly because the
 * 8259 is configured for level sensitive IRQ 14 and so wants the
 * ATA controller to be set to fully native mode or bad things
 * will happen.
 */
static void chrp_pci_fixup_winbond_ata(struct pci_dev *sl82c105)
{
        u8 progif;

        /* If non-briq machines need that fixup too, please speak up */
        if (!machine_is(chrp) || _chrp_type != _CHRP_briq)
                return;

        if ((sl82c105->class & 5) != 5) {
                printk("W83C553: Switching SL82C105 IDE to PCI native mode\n");
                /* Enable SL82C105 PCI native IDE mode */
                pci_read_config_byte(sl82c105, PCI_CLASS_PROG, &progif);
                pci_write_config_byte(sl82c105, PCI_CLASS_PROG, progif | 0x05);
                sl82c105->class |= 0x05;
                /* Disable SL82C105 second port */
                pci_write_config_word(sl82c105, SL82C105_IDECSR, 0x0003);
                /* Clear IO BARs, they will be reassigned */
                pci_write_config_dword(sl82c105, PCI_BASE_ADDRESS_0, 0);
                pci_write_config_dword(sl82c105, PCI_BASE_ADDRESS_1, 0);
                pci_write_config_dword(sl82c105, PCI_BASE_ADDRESS_2, 0);
                pci_write_config_dword(sl82c105, PCI_BASE_ADDRESS_3, 0);
        }
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_WINBOND, PCI_DEVICE_ID_WINBOND_82C105,
                        chrp_pci_fixup_winbond_ata);

/* Pegasos2 firmware version 20040810 configures the built-in IDE controller
 * in legacy mode, but sets the PCI registers to PCI native mode.
 * The chip can only operate in legacy mode, so force the PCI class into legacy
 * mode as well. The same fixup must be done to the class-code property in
 * the IDE node /pci@80000000/ide@C,1
 */
static void chrp_pci_fixup_vt8231_ata(struct pci_dev *viaide)
{
        u8 progif;
        struct pci_dev *viaisa;

        if (!machine_is(chrp) || _chrp_type != _CHRP_Pegasos)
                return;
        if (viaide->irq != 14)
                return;

        viaisa = pci_get_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231, NULL);
        if (!viaisa)
                return;
        dev_info(&viaide->dev, "Fixing VIA IDE, force legacy mode on\n");

        pci_read_config_byte(viaide, PCI_CLASS_PROG, &progif);
        pci_write_config_byte(viaide, PCI_CLASS_PROG, progif & ~0x5);
        viaide->class &= ~0x5;

        pci_dev_put(viaisa);
}
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_1, chrp_pci_fixup_vt8231_ata);