/**
 * \file plat_apm88xxxx.c
 * \brief
 */

/*
 * Copyright (c) 2016 ETH Zurich.
 * All rights reserved.
 *
 * This file is distributed under the terms in the attached LICENSE file.
 * If you do not find this file, copies can be found by writing to:
 * ETH Zurich D-INFK, Universitaetsstrasse 6, CH-8092 Zurich. Attn: Systems Group.
 */

#include <kernel.h>
#include <offsets.h>
#include <platform.h>
#include <serial.h>
#include <dev/apm88xxxx/apm88xxxx_pc16550_dev.h>
#include <arch/arm/gic.h>
#include <sysreg.h>
#include <dev/armv8_dev.h>
#include <barrelfish_kpi/arm_core_data.h>
#include <psci.h>
#include <arch/armv8/global.h>
#include <arch/armv8/gic_v3.h>
#include <paging_kernel_arch.h>

/* the maximum number of UARTS supported */
#define MAX_NUM_UARTS 4

static apm88xxxx_pc16550_t ports[MAX_NUM_UARTS];


errval_t serial_init(unsigned port, bool initialize_hw)
{
    if (port >= MAX_NUM_UARTS) {
        return SYS_ERR_SERIAL_PORT_INVALID;
    }

    if ((lpaddr_t)ports[port].base == (uart_base[port] + KERNEL_OFFSET)) {
        return SYS_ERR_OK;
    }

    apm88xxxx_pc16550_t *uart = &ports[port];
    apm88xxxx_pc16550_initialize(uart, (mackerel_addr_t)(uart_base[port] + KERNEL_OFFSET));

    if (!initialize_hw) {
        // hw initialized, this is for non-bsp cores, where hw has been
        // initialized by bsp core and we come through here just to setup our
        // local apm88xxxx_pc16550 struct for the port.
        return SYS_ERR_OK;
    }

    panic("device init NYI");
    return SYS_ERR_OK;
}

errval_t serial_early_init(unsigned port)
{
    if (port >= MAX_NUM_UARTS) {
        return SYS_ERR_SERIAL_PORT_INVALID;
    }

    if ((lpaddr_t)ports[port].base == uart_base[port]) {
        return SYS_ERR_OK;
    }

    apm88xxxx_pc16550_t *uart = &ports[port];
    apm88xxxx_pc16550_initialize(uart, (mackerel_addr_t)uart_base[port]);
    return SYS_ERR_OK;
}

errval_t serial_early_init_mmu_enabled(unsigned port)
{
    return serial_early_init(port);
}


/**
 * \brief Prints a single character to a serial port.
 */
void serial_putchar(unsigned port, char c)
{
    assert(port < MAX_NUM_UARTS);
    assert(ports[port].base != 0);
    // Wait until FIFO can hold more characters
    while(!apm88xxxx_pc16550_LSR_thre_rdf(&ports[port]));
    // Write character
    apm88xxxx_pc16550_THR_thr_wrf(&ports[port], c);
}

/**
 * \brief Reads a single character from the default serial port.
 * This function spins waiting for a character to arrive.
 */
char serial_getchar(unsigned port)
{
    assert(port < MAX_NUM_UARTS);
    assert(ports[port].base != 0);

    // Wait until character available
    while(!apm88xxxx_pc16550_LSR_dr_rdf(&ports[port]));
    // Read a character from FIFO
    return apm88xxxx_pc16550_RBR_rbr_rdf(&ports[port]);
}


void platform_get_info(struct platform_info *pi)
{
    pi->arch = PI_ARCH_ARMV8A;
    pi->platform = PI_PLATFORM_APM88XXXX;
}

void armv8_get_info(struct arch_info_armv8 *ai)
{

}

/* GIC */

errval_t platform_boot_core(hwid_t target, genpaddr_t gen_entry, genpaddr_t context)
{
    printf("Invoking PSCI on: cpu=0x%lx, entry=0x%lx, context=0x%lx\n", target, gen_entry, context);
    struct armv8_core_data *cd = (struct armv8_core_data *)local_phys_to_mem(context);
    cd->page_table_root = armv8_TTBR1_EL1_rd(NULL);
    cd->cpu_driver_globals_pointer = (uintptr_t)global;
    __asm volatile("dsb   sy\n"
                   "dmb   sy\n"
                   "isb     \n");

    /*
     * An IRQ interrupt, even if the PSTATE I-bit is set.
An FIQ interrupt, even if the PSTATE F-bit is set.
     *
     *
     */

    gic_raise_softirq(target, 1);
     
    return SYS_ERR_OK;
}