/*
 * Nordic Semiconductor nRF51 non-volatile memory
 *
 * It provides an interface to erase regions in flash memory.
 * Furthermore it provides the user and factory information registers.
 *
 * Reference Manual: http://infocenter.nordicsemi.com/pdf/nRF51_RM_v3.0.pdf
 *
 * See nRF51 reference manual and product sheet sections:
 * + Non-Volatile Memory Controller (NVMC)
 * + Factory Information Configuration Registers (FICR)
 * + User Information Configuration Registers (UICR)
 *
 * Copyright 2018 Steffen Görtz <contrib@steffen-goertz.de>
 *
 * This code is licensed under the GPL version 2 or later.  See
 * the COPYING file in the top-level directory.
 */

#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/log.h"
#include "qemu/module.h"
#include "hw/arm/nrf51.h"
#include "hw/nvram/nrf51_nvm.h"
#include "hw/qdev-properties.h"
#include "migration/vmstate.h"

/*
 * FICR Registers Assignments
 * CODEPAGESIZE      0x010
 * CODESIZE          0x014
 * CLENR0            0x028
 * PPFC              0x02C
 * NUMRAMBLOCK       0x034
 * SIZERAMBLOCKS     0x038
 * SIZERAMBLOCK[0]   0x038
 * SIZERAMBLOCK[1]   0x03C
 * SIZERAMBLOCK[2]   0x040
 * SIZERAMBLOCK[3]   0x044
 * CONFIGID          0x05C
 * DEVICEID[0]       0x060
 * DEVICEID[1]       0x064
 * ER[0]             0x080
 * ER[1]             0x084
 * ER[2]             0x088
 * ER[3]             0x08C
 * IR[0]             0x090
 * IR[1]             0x094
 * IR[2]             0x098
 * IR[3]             0x09C
 * DEVICEADDRTYPE    0x0A0
 * DEVICEADDR[0]     0x0A4
 * DEVICEADDR[1]     0x0A8
 * OVERRIDEEN        0x0AC
 * NRF_1MBIT[0]      0x0B0
 * NRF_1MBIT[1]      0x0B4
 * NRF_1MBIT[2]      0x0B8
 * NRF_1MBIT[3]      0x0BC
 * NRF_1MBIT[4]      0x0C0
 * BLE_1MBIT[0]      0x0EC
 * BLE_1MBIT[1]      0x0F0
 * BLE_1MBIT[2]      0x0F4
 * BLE_1MBIT[3]      0x0F8
 * BLE_1MBIT[4]      0x0FC
 */
static const uint32_t ficr_content[64] = {
    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000400,
    0x00000100, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000002, 0x00002000,
    0x00002000, 0x00002000, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000003,
    0x12345678, 0x9ABCDEF1, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,
    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF
};

static uint64_t ficr_read(void *opaque, hwaddr offset, unsigned int size)
{
    assert(offset < sizeof(ficr_content));
    return ficr_content[offset / 4];
}

static void ficr_write(void *opaque, hwaddr offset, uint64_t value,
        unsigned int size)
{
    /* Intentionally do nothing */
}

static const MemoryRegionOps ficr_ops = {
    .read = ficr_read,
    .write = ficr_write,
    .impl.min_access_size = 4,
    .impl.max_access_size = 4,
    .endianness = DEVICE_LITTLE_ENDIAN
};

/*
 * UICR Registers Assignments
 * CLENR0           0x000
 * RBPCONF          0x004
 * XTALFREQ         0x008
 * FWID             0x010
 * BOOTLOADERADDR   0x014
 * NRFFW[0]         0x014
 * NRFFW[1]         0x018
 * NRFFW[2]         0x01C
 * NRFFW[3]         0x020
 * NRFFW[4]         0x024
 * NRFFW[5]         0x028
 * NRFFW[6]         0x02C
 * NRFFW[7]         0x030
 * NRFFW[8]         0x034
 * NRFFW[9]         0x038
 * NRFFW[10]        0x03C
 * NRFFW[11]        0x040
 * NRFFW[12]        0x044
 * NRFFW[13]        0x048
 * NRFFW[14]        0x04C
 * NRFHW[0]         0x050
 * NRFHW[1]         0x054
 * NRFHW[2]         0x058
 * NRFHW[3]         0x05C
 * NRFHW[4]         0x060
 * NRFHW[5]         0x064
 * NRFHW[6]         0x068
 * NRFHW[7]         0x06C
 * NRFHW[8]         0x070
 * NRFHW[9]         0x074
 * NRFHW[10]        0x078
 * NRFHW[11]        0x07C
 * CUSTOMER[0]      0x080
 * CUSTOMER[1]      0x084
 * CUSTOMER[2]      0x088
 * CUSTOMER[3]      0x08C
 * CUSTOMER[4]      0x090
 * CUSTOMER[5]      0x094
 * CUSTOMER[6]      0x098
 * CUSTOMER[7]      0x09C
 * CUSTOMER[8]      0x0A0
 * CUSTOMER[9]      0x0A4
 * CUSTOMER[10]     0x0A8
 * CUSTOMER[11]     0x0AC
 * CUSTOMER[12]     0x0B0
 * CUSTOMER[13]     0x0B4
 * CUSTOMER[14]     0x0B8
 * CUSTOMER[15]     0x0BC
 * CUSTOMER[16]     0x0C0
 * CUSTOMER[17]     0x0C4
 * CUSTOMER[18]     0x0C8
 * CUSTOMER[19]     0x0CC
 * CUSTOMER[20]     0x0D0
 * CUSTOMER[21]     0x0D4
 * CUSTOMER[22]     0x0D8
 * CUSTOMER[23]     0x0DC
 * CUSTOMER[24]     0x0E0
 * CUSTOMER[25]     0x0E4
 * CUSTOMER[26]     0x0E8
 * CUSTOMER[27]     0x0EC
 * CUSTOMER[28]     0x0F0
 * CUSTOMER[29]     0x0F4
 * CUSTOMER[30]     0x0F8
 * CUSTOMER[31]     0x0FC
 */

static uint64_t uicr_read(void *opaque, hwaddr offset, unsigned int size)
{
    NRF51NVMState *s = NRF51_NVM(opaque);

    assert(offset < sizeof(s->uicr_content));
    return s->uicr_content[offset / 4];
}

static void uicr_write(void *opaque, hwaddr offset, uint64_t value,
        unsigned int size)
{
    NRF51NVMState *s = NRF51_NVM(opaque);

    assert(offset < sizeof(s->uicr_content));
    s->uicr_content[offset / 4] = value;
}

static const MemoryRegionOps uicr_ops = {
    .read = uicr_read,
    .write = uicr_write,
    .impl.min_access_size = 4,
    .impl.max_access_size = 4,
    .endianness = DEVICE_LITTLE_ENDIAN
};


static uint64_t io_read(void *opaque, hwaddr offset, unsigned int size)
{
    NRF51NVMState *s = NRF51_NVM(opaque);
    uint64_t r = 0;

    switch (offset) {
    case NRF51_NVMC_READY:
        r = NRF51_NVMC_READY_READY;
        break;
    case NRF51_NVMC_CONFIG:
        r = s->config;
        break;
    default:
        qemu_log_mask(LOG_GUEST_ERROR,
                "%s: bad read offset 0x%" HWADDR_PRIx "\n", __func__, offset);
        break;
    }

    return r;
}

static void io_write(void *opaque, hwaddr offset, uint64_t value,
        unsigned int size)
{
    NRF51NVMState *s = NRF51_NVM(opaque);

    switch (offset) {
    case NRF51_NVMC_CONFIG:
        s->config = value & NRF51_NVMC_CONFIG_MASK;
        break;
    case NRF51_NVMC_ERASEPCR0:
    case NRF51_NVMC_ERASEPCR1:
        if (s->config & NRF51_NVMC_CONFIG_EEN) {
            /* Mask in-page sub address */
            value &= ~(NRF51_PAGE_SIZE - 1);
            if (value <= (s->flash_size - NRF51_PAGE_SIZE)) {
                memset(s->storage + value, 0xFF, NRF51_PAGE_SIZE);
                memory_region_flush_rom_device(&s->flash, value,
                                               NRF51_PAGE_SIZE);
            }
        } else {
            qemu_log_mask(LOG_GUEST_ERROR,
            "%s: Flash erase at 0x%" HWADDR_PRIx" while flash not erasable.\n",
            __func__, offset);
        }
        break;
    case NRF51_NVMC_ERASEALL:
        if (value == NRF51_NVMC_ERASE) {
            if (s->config & NRF51_NVMC_CONFIG_EEN) {
                memset(s->storage, 0xFF, s->flash_size);
                memory_region_flush_rom_device(&s->flash, 0, s->flash_size);
                memset(s->uicr_content, 0xFF, sizeof(s->uicr_content));
            } else {
                qemu_log_mask(LOG_GUEST_ERROR, "%s: Flash not erasable.\n",
                              __func__);
            }
        }
        break;
    case NRF51_NVMC_ERASEUICR:
        if (value == NRF51_NVMC_ERASE) {
            memset(s->uicr_content, 0xFF, sizeof(s->uicr_content));
        }
        break;

    default:
        qemu_log_mask(LOG_GUEST_ERROR,
                "%s: bad write offset 0x%" HWADDR_PRIx "\n", __func__, offset);
    }
}

static const MemoryRegionOps io_ops = {
        .read = io_read,
        .write = io_write,
        .impl.min_access_size = 4,
        .impl.max_access_size = 4,
        .endianness = DEVICE_LITTLE_ENDIAN,
};

static uint64_t flash_read(void *opaque, hwaddr offset, unsigned size)
{
    /*
     * This is a rom_device MemoryRegion which is always in
     * romd_mode (we never put it in MMIO mode), so reads always
     * go directly to RAM and never come here.
     */
    g_assert_not_reached();
}

static void flash_write(void *opaque, hwaddr offset, uint64_t value,
        unsigned int size)
{
    NRF51NVMState *s = NRF51_NVM(opaque);

    if (s->config & NRF51_NVMC_CONFIG_WEN) {
        uint32_t oldval;

        assert(offset + size <= s->flash_size);

        /* NOR Flash only allows bits to be flipped from 1's to 0's on write */
        oldval = ldl_le_p(s->storage + offset);
        oldval &= value;
        stl_le_p(s->storage + offset, oldval);

        memory_region_flush_rom_device(&s->flash, offset, size);
    } else {
        qemu_log_mask(LOG_GUEST_ERROR,
                "%s: Flash write 0x%" HWADDR_PRIx" while flash not writable.\n",
                __func__, offset);
    }
}


static const MemoryRegionOps flash_ops = {
    .read = flash_read,
    .write = flash_write,
    .valid.min_access_size = 4,
    .valid.max_access_size = 4,
    .endianness = DEVICE_LITTLE_ENDIAN,
};

static void nrf51_nvm_init(Object *obj)
{
    NRF51NVMState *s = NRF51_NVM(obj);
    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);

    memory_region_init_io(&s->mmio, obj, &io_ops, s, "nrf51_soc.nvmc",
                          NRF51_NVMC_SIZE);
    sysbus_init_mmio(sbd, &s->mmio);

    memory_region_init_io(&s->ficr, obj, &ficr_ops, s, "nrf51_soc.ficr",
                          sizeof(ficr_content));
    sysbus_init_mmio(sbd, &s->ficr);

    memory_region_init_io(&s->uicr, obj, &uicr_ops, s, "nrf51_soc.uicr",
                          sizeof(s->uicr_content));
    sysbus_init_mmio(sbd, &s->uicr);
}

static void nrf51_nvm_realize(DeviceState *dev, Error **errp)
{
    NRF51NVMState *s = NRF51_NVM(dev);

    if (!memory_region_init_rom_device(&s->flash, OBJECT(dev), &flash_ops, s,
                                       "nrf51_soc.flash", s->flash_size, errp)) {
        return;
    }

    s->storage = memory_region_get_ram_ptr(&s->flash);
    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->flash);
}

static void nrf51_nvm_reset(DeviceState *dev)
{
    NRF51NVMState *s = NRF51_NVM(dev);

    s->config = 0x00;
    memset(s->uicr_content, 0xFF, sizeof(s->uicr_content));
}

static Property nrf51_nvm_properties[] = {
    DEFINE_PROP_UINT32("flash-size", NRF51NVMState, flash_size, 0x40000),
    DEFINE_PROP_END_OF_LIST(),
};

static const VMStateDescription vmstate_nvm = {
    .name = "nrf51_soc.nvm",
    .version_id = 1,
    .minimum_version_id = 1,
    .fields = (const VMStateField[]) {
        VMSTATE_UINT32_ARRAY(uicr_content, NRF51NVMState,
                NRF51_UICR_FIXTURE_SIZE),
        VMSTATE_UINT32(config, NRF51NVMState),
        VMSTATE_END_OF_LIST()
    }
};

static void nrf51_nvm_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);

    device_class_set_props(dc, nrf51_nvm_properties);
    dc->vmsd = &vmstate_nvm;
    dc->realize = nrf51_nvm_realize;
    device_class_set_legacy_reset(dc, nrf51_nvm_reset);
}

static const TypeInfo nrf51_nvm_info = {
    .name = TYPE_NRF51_NVM,
    .parent = TYPE_SYS_BUS_DEVICE,
    .instance_size = sizeof(NRF51NVMState),
    .instance_init = nrf51_nvm_init,
    .class_init = nrf51_nvm_class_init
};

static void nrf51_nvm_register_types(void)
{
    type_register_static(&nrf51_nvm_info);
}

type_init(nrf51_nvm_register_types)