// 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);