/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2008 VIA Technologies, Inc.
 * (Written by Aaron Lwe <aaron.lwe@gmail.com> for VIA)
 * Copyright (C) 2007 Corey Osgood <corey.osgood@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <console/console.h>
#include <arch/io.h>
#include <stdint.h>
#include <device/device.h>
#include <device/pci.h>
#include <device/pci_ids.h>
#include <stdlib.h>
#include <string.h>
#include <bitops.h>
#include <cpu/cpu.h>
#include "chip.h"
#include "northbridge.h"
#include "cn700.h"

static void memctrl_init(device_t dev)
{
	device_t vlink_dev;
	u16 reg16;
	u8 ranks;
	u8 pagec, paged, pagee, pagef;
	u8 shadowreg;
	
	/* Set up the vga framebuffer size */
	reg16 = (log2(CONFIG_VIDEO_MB) << 12) | (1 << 15);
	pci_write_config16(dev, 0xa0, reg16);
	
	/* Set up VGA timers */
	pci_write_config8(dev, 0xa2, 0x44);
	
	for (ranks = 0x4b; ranks >= 0x48; ranks--) {
		if (pci_read_config8(dev, ranks)) {
			ranks -= 0x48;
			break;
		}
	}
	if (ranks == 0x47)
		ranks = 0x00;
	reg16 = 0xaae0;
	reg16 |= ranks;
	/* GMINT Misc. FrameBuffer rank */
	pci_write_config16(dev, 0xb0, reg16);
	/* AGPCINT Misc. */
	pci_write_config8(dev, 0xb8, 0x08);

	/* shadown ram */
	pagec = 0xff, paged = 0xff, pagee = 0xff, pagef = 0x30;
	/* PAGE C, D, E are all read write enable */
	pci_write_config8(dev, 0x80, pagec);
	pci_write_config8(dev, 0x81, paged);
	pci_write_config8(dev, 0x82, pagee);
	/* PAGE F are read/writable */
	shadowreg = pci_read_config8(dev, 0x83);
	shadowreg |= pagef;
	pci_write_config8(dev, 0x83, shadowreg);
	/* vlink mirror */
	vlink_dev = dev_find_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CN700_VLINK, 0);
	if (vlink_dev) {
		pci_write_config8(vlink_dev, 0x61, pagec);
		pci_write_config8(vlink_dev, 0x62, paged);
		pci_write_config8(vlink_dev, 0x64, pagee);
		shadowreg = pci_read_config8(vlink_dev, 0x63);
		shadowreg |= pagef;
		pci_write_config8(vlink_dev, 0x63, shadowreg);
	}
}

static const struct device_operations memctrl_operations = {
	.read_resources = cn700_noop,
	.init = memctrl_init,
};

static const struct pci_driver memctrl_driver __pci_driver = {
	.ops = &memctrl_operations,
	.vendor = PCI_VENDOR_ID_VIA,
	.device = PCI_DEVICE_ID_VIA_CN700_MEMCTRL,
};

static void pci_domain_read_resources(device_t dev)
{
        struct resource *resource;

	printk_spew("Entering cn700 pci_domain_read_resources.\n");

        /* Initialize the system wide io space constraints */
        resource = new_resource(dev, IOINDEX_SUBTRACTIVE(0,0));
        resource->limit = 0xffffUL;
        resource->flags = IORESOURCE_IO | IORESOURCE_SUBTRACTIVE |
		IORESOURCE_ASSIGNED;

        /* Initialize the system wide memory resources constraints */
        resource = new_resource(dev, IOINDEX_SUBTRACTIVE(1,0));
        resource->limit = 0xffffffffULL;
        resource->flags = IORESOURCE_MEM | IORESOURCE_SUBTRACTIVE |
		IORESOURCE_ASSIGNED;

	printk_spew("Leaving cn700 pci_domain_read_resources.\n");
}

static void ram_resource(device_t dev, unsigned long index,
        unsigned long basek, unsigned long sizek)
{
        struct resource *resource;

        if (!sizek) {
                return;
        }
        resource = new_resource(dev, index);
        resource->base  = ((resource_t)basek) << 10;
        resource->size  = ((resource_t)sizek) << 10;
        resource->flags =  IORESOURCE_MEM | IORESOURCE_CACHEABLE | \
                IORESOURCE_FIXED | IORESOURCE_STORED | IORESOURCE_ASSIGNED;
}

static void tolm_test(void *gp, struct device *dev, struct resource *new)
{
	struct resource **best_p = gp;
	struct resource *best;
	best = *best_p;
	if (!best || (best->base > new->base)) {
		best = new;
	}
	*best_p = best;
}

static u32 find_pci_tolm(struct bus *bus)
{
	print_debug("Entering find_pci_tolm\n");
	struct resource *min;
	u32 tolm;
	min = 0;
	search_bus_resources(bus, IORESOURCE_MEM, IORESOURCE_MEM, tolm_test, &min);
	tolm = 0xffffffffUL;
	if (min && tolm > min->base) {
		tolm = min->base;
	}
	print_debug("Leaving find_pci_tolm\n");
	return tolm;
}

static void pci_domain_set_resources(device_t dev)
{
	/* 
	 * the order is important to find the correct ram size.
	 */
	static const u8 ramregs[] = {0x43, 0x42, 0x41, 0x40};
	device_t mc_dev;
        u32 pci_tolm;

	printk_spew("Entering cn700 pci_domain_set_resources.\n");

        pci_tolm = find_pci_tolm(&dev->link[0]);
	mc_dev = dev_find_device(PCI_VENDOR_ID_VIA, 
				PCI_DEVICE_ID_VIA_CN700_MEMCTRL, 0);

	if (mc_dev) {
		unsigned long tomk, tolmk;
		unsigned char rambits;
		int i, idx;

		/*
		 * once the register value is not zero, the ramsize is
		 * this register's value multiply 64 * 1024 * 1024
		 */
		for(rambits = 0, i = 0; i < ARRAY_SIZE(ramregs); i++) {
			unsigned char reg;
			rambits = pci_read_config8(mc_dev, ramregs[i]);
			if (rambits != 0)
				break;
		}
		
		tomk = rambits * 64 * 1024;
		printk_spew("tomk is 0x%x\n", tomk);
		/* Compute the Top Of Low Memory, in Kb */
		tolmk = pci_tolm >> 10;
		if (tolmk >= tomk) {
			/* The PCI hole does does not overlap the memory. */
			tolmk = tomk;
		}
		/* Report the memory regions */
		idx = 10;
		/* TODO: Hole needed? */
		ram_resource(dev, idx++, 0, 640); /* first 640k */
		/* Leave a hole for vga, 0xa0000 - 0xc0000 */
		ram_resource(dev, idx++, 768, (tolmk - 768 - CONFIG_VIDEO_MB * 1024));
	}
	assign_resources(&dev->link[0]);
}

static unsigned int pci_domain_scan_bus(device_t dev, unsigned int max)
{
	printk_debug("Entering cn700 pci_domain_scan_bus.\n");

        max = pci_scan_bus(&dev->link[0], PCI_DEVFN(0, 0), 0xff, max);
        return max;
}

static const struct device_operations pci_domain_ops = {
        .read_resources   = pci_domain_read_resources,
        .set_resources    = pci_domain_set_resources,
        .enable_resources = enable_childrens_resources,
        .init             = 0,
        .scan_bus         = pci_domain_scan_bus,
};  

static void cpu_bus_init(device_t dev)
{
        initialize_cpus(&dev->link[0]);
}

static void cpu_bus_noop(device_t dev)
{
}

static const struct device_operations cpu_bus_ops = {
        .read_resources   = cpu_bus_noop,
        .set_resources    = cpu_bus_noop,
        .enable_resources = cpu_bus_noop,
        .init             = cpu_bus_init,
        .scan_bus         = 0,
};

static void enable_dev(struct device *dev)
{
	printk_spew("In cn700 enable_dev for device %s.\n", dev_path(dev));

        /* Set the operations if it is a special bus type */
        if (dev->path.type == DEVICE_PATH_PCI_DOMAIN) {
                dev->ops = &pci_domain_ops;
		pci_set_method(dev);
        }
        else if (dev->path.type == DEVICE_PATH_APIC_CLUSTER) {
                dev->ops = &cpu_bus_ops;
        }
}

struct chip_operations northbridge_via_cn700_ops = {
	CHIP_NAME("VIA CN700 Northbridge")
	.enable_dev = enable_dev,
};
