/*
 * OpenRISC setup.c
 *
 * Linux architectural port borrowing liberally from similar works of
 * others.  All original copyrights apply as per the original source
 * declaration.
 *
 * Modifications for the OpenRISC architecture:
 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
 *
 *      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 file handles the architecture-dependent parts of initialization
 */

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/console.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/seq_file.h>
#include <linux/serial.h>
#include <linux/initrd.h>
#include <linux/of_fdt.h>
#include <linux/of.h>
#include <linux/memblock.h>
#include <linux/device.h>
#include <linux/of_platform.h>

#include <asm/sections.h>
#include <asm/segment.h>
#include <asm/pgtable.h>
#include <asm/types.h>
#include <asm/setup.h>
#include <asm/io.h>
#include <asm/cpuinfo.h>
#include <asm/delay.h>

#include "vmlinux.h"

static unsigned long __init setup_memory(void)
{
        unsigned long bootmap_size;
        unsigned long ram_start_pfn;
        unsigned long free_ram_start_pfn;
        unsigned long ram_end_pfn;
        phys_addr_t memory_start, memory_end;
        struct memblock_region *region;

        memory_end = memory_start = 0;

        /* Find main memory where is the kernel */
        for_each_memblock(memory, region) {
                memory_start = region->base;
                memory_end = region->base + region->size;
                printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__,
                       memory_start, memory_end);
        }

        if (!memory_end) {
                panic("No memory!");
        }

        ram_start_pfn = PFN_UP(memory_start);
        /* free_ram_start_pfn is first page after kernel */
        free_ram_start_pfn = PFN_UP(__pa(_end));
        ram_end_pfn = PFN_DOWN(memblock_end_of_DRAM());

        max_pfn = ram_end_pfn;

        /*
         * initialize the boot-time allocator (with low memory only).
         *
         * This makes the memory from the end of the kernel to the end of
         * RAM usable.
         * init_bootmem sets the global values min_low_pfn, max_low_pfn.
         */
        bootmap_size = init_bootmem(free_ram_start_pfn,
                                    ram_end_pfn - ram_start_pfn);
        free_bootmem(PFN_PHYS(free_ram_start_pfn),
                     (ram_end_pfn - free_ram_start_pfn) << PAGE_SHIFT);
        reserve_bootmem(PFN_PHYS(free_ram_start_pfn), bootmap_size,
                        BOOTMEM_DEFAULT);

        for_each_memblock(reserved, region) {
                printk(KERN_INFO "Reserved - 0x%08x-0x%08x\n",
                       (u32) region->base, (u32) region->size);
                reserve_bootmem(region->base, region->size, BOOTMEM_DEFAULT);
        }

        return ram_end_pfn;
}

struct cpuinfo cpuinfo;

static void print_cpuinfo(void)
{
        unsigned long upr = mfspr(SPR_UPR);
        unsigned long vr = mfspr(SPR_VR);
        unsigned int version;
        unsigned int revision;

        version = (vr & SPR_VR_VER) >> 24;
        revision = (vr & SPR_VR_REV);

        printk(KERN_INFO "CPU: OpenRISC-%x (revision %d) @%d MHz\n",
               version, revision, cpuinfo.clock_frequency / 1000000);

        if (!(upr & SPR_UPR_UP)) {
                printk(KERN_INFO
                       "-- no UPR register... unable to detect configuration\n");
                return;
        }

        if (upr & SPR_UPR_DCP)
                printk(KERN_INFO
                       "-- dcache: %4d bytes total, %2d bytes/line, %d way(s)\n",
                       cpuinfo.dcache_size, cpuinfo.dcache_block_size, 1);
        else
                printk(KERN_INFO "-- dcache disabled\n");
        if (upr & SPR_UPR_ICP)
                printk(KERN_INFO
                       "-- icache: %4d bytes total, %2d bytes/line, %d way(s)\n",
                       cpuinfo.icache_size, cpuinfo.icache_block_size, 1);
        else
                printk(KERN_INFO "-- icache disabled\n");

        if (upr & SPR_UPR_DMP)
                printk(KERN_INFO "-- dmmu: %4d entries, %lu way(s)\n",
                       1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
                       1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
        if (upr & SPR_UPR_IMP)
                printk(KERN_INFO "-- immu: %4d entries, %lu way(s)\n",
                       1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
                       1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));

        printk(KERN_INFO "-- additional features:\n");
        if (upr & SPR_UPR_DUP)
                printk(KERN_INFO "-- debug unit\n");
        if (upr & SPR_UPR_PCUP)
                printk(KERN_INFO "-- performance counters\n");
        if (upr & SPR_UPR_PMP)
                printk(KERN_INFO "-- power management\n");
        if (upr & SPR_UPR_PICP)
                printk(KERN_INFO "-- PIC\n");
        if (upr & SPR_UPR_TTP)
                printk(KERN_INFO "-- timer\n");
        if (upr & SPR_UPR_CUP)
                printk(KERN_INFO "-- custom unit(s)\n");
}

void __init setup_cpuinfo(void)
{
        struct device_node *cpu;
        unsigned long iccfgr, dccfgr;
        unsigned long cache_set_size, cache_ways;

        cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");
        if (!cpu)
                panic("No compatible CPU found in device tree...\n");

        iccfgr = mfspr(SPR_ICCFGR);
        cache_ways = 1 << (iccfgr & SPR_ICCFGR_NCW);
        cache_set_size = 1 << ((iccfgr & SPR_ICCFGR_NCS) >> 3);
        cpuinfo.icache_block_size = 16 << ((iccfgr & SPR_ICCFGR_CBS) >> 7);
        cpuinfo.icache_size =
            cache_set_size * cache_ways * cpuinfo.icache_block_size;

        dccfgr = mfspr(SPR_DCCFGR);
        cache_ways = 1 << (dccfgr & SPR_DCCFGR_NCW);
        cache_set_size = 1 << ((dccfgr & SPR_DCCFGR_NCS) >> 3);
        cpuinfo.dcache_block_size = 16 << ((dccfgr & SPR_DCCFGR_CBS) >> 7);
        cpuinfo.dcache_size =
            cache_set_size * cache_ways * cpuinfo.dcache_block_size;

        if (of_property_read_u32(cpu, "clock-frequency",
                                 &cpuinfo.clock_frequency)) {
                printk(KERN_WARNING
                       "Device tree missing CPU 'clock-frequency' parameter."
                       "Assuming frequency 25MHZ"
                       "This is probably not what you want.");
        }

        of_node_put(cpu);

        print_cpuinfo();
}

/**
 * or32_early_setup
 *
 * Handles the pointer to the device tree that this kernel is to use
 * for establishing the available platform devices.
 *
 * Falls back on built-in device tree in case null pointer is passed.
 */

void __init or32_early_setup(void *fdt)
{
        if (fdt)
                pr_info("FDT at %p\n", fdt);
        else {
                fdt = __dtb_start;
                pr_info("Compiled-in FDT at %p\n", fdt);
        }
        early_init_devtree(fdt);
}

static int __init openrisc_device_probe(void)
{
        of_platform_populate(NULL, NULL, NULL, NULL);

        return 0;
}

device_initcall(openrisc_device_probe);

static inline unsigned long extract_value_bits(unsigned long reg,
                                               short bit_nr, short width)
{
        return (reg >> bit_nr) & (0 << width);
}

static inline unsigned long extract_value(unsigned long reg, unsigned long mask)
{
        while (!(mask & 0x1)) {
                reg = reg >> 1;
                mask = mask >> 1;
        }
        return mask & reg;
}

void __init detect_unit_config(unsigned long upr, unsigned long mask,
                               char *text, void (*func) (void))
{
        if (text != NULL)
                printk("%s", text);

        if (upr & mask) {
                if (func != NULL)
                        func();
                else
                        printk("present\n");
        } else
                printk("not present\n");
}

/*
 * calibrate_delay
 *
 * Lightweight calibrate_delay implementation that calculates loops_per_jiffy
 * from the clock frequency passed in via the device tree
 *
 */

void calibrate_delay(void)
{
        const int *val;
        struct device_node *cpu = NULL;
        cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");
        val = of_get_property(cpu, "clock-frequency", NULL);
        if (!val)
                panic("no cpu 'clock-frequency' parameter in device tree");
        loops_per_jiffy = *val / HZ;
        pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
                loops_per_jiffy / (500000 / HZ),
                (loops_per_jiffy / (5000 / HZ)) % 100, loops_per_jiffy);
}

void __init setup_arch(char **cmdline_p)
{
        unsigned long max_low_pfn;

        unflatten_and_copy_device_tree();

        setup_cpuinfo();

        /* process 1's initial memory region is the kernel code/data */
        init_mm.start_code = (unsigned long)_stext;
        init_mm.end_code = (unsigned long)_etext;
        init_mm.end_data = (unsigned long)_edata;
        init_mm.brk = (unsigned long)_end;

#ifdef CONFIG_BLK_DEV_INITRD
        initrd_start = (unsigned long)&__initrd_start;
        initrd_end = (unsigned long)&__initrd_end;
        if (initrd_start == initrd_end) {
                initrd_start = 0;
                initrd_end = 0;
        }
        initrd_below_start_ok = 1;
#endif

        /* setup bootmem allocator */
        max_low_pfn = setup_memory();

        /* paging_init() sets up the MMU and marks all pages as reserved */
        paging_init();

#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
        if (!conswitchp)
                conswitchp = &dummy_con;
#endif

        *cmdline_p = boot_command_line;

        printk(KERN_INFO "OpenRISC Linux -- http://openrisc.net\n");
}

static int show_cpuinfo(struct seq_file *m, void *v)
{
        unsigned long vr;
        int version, revision;

        vr = mfspr(SPR_VR);
        version = (vr & SPR_VR_VER) >> 24;
        revision = vr & SPR_VR_REV;

        seq_printf(m,
                   "cpu\t\t: OpenRISC-%x\n"
                   "revision\t: %d\n"
                   "frequency\t: %ld\n"
                   "dcache size\t: %d bytes\n"
                   "dcache block size\t: %d bytes\n"
                   "icache size\t: %d bytes\n"
                   "icache block size\t: %d bytes\n"
                   "immu\t\t: %d entries, %lu ways\n"
                   "dmmu\t\t: %d entries, %lu ways\n"
                   "bogomips\t: %lu.%02lu\n",
                   version,
                   revision,
                   loops_per_jiffy * HZ,
                   cpuinfo.dcache_size,
                   cpuinfo.dcache_block_size,
                   cpuinfo.icache_size,
                   cpuinfo.icache_block_size,
                   1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
                   1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW),
                   1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
                   1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW),
                   (loops_per_jiffy * HZ) / 500000,
                   ((loops_per_jiffy * HZ) / 5000) % 100);

        return 0;
}

static void *c_start(struct seq_file *m, loff_t * pos)
{
        /* We only have one CPU... */
        return *pos < 1 ? (void *)1 : NULL;
}

static void *c_next(struct seq_file *m, void *v, loff_t * pos)
{
        ++*pos;
        return NULL;
}

static void c_stop(struct seq_file *m, void *v)
{
}

const struct seq_operations cpuinfo_op = {
        .start = c_start,
        .next = c_next,
        .stop = c_stop,
        .show = show_cpuinfo,
};