/*
 * QEMU PC keyboard emulation
 *
 * Copyright (c) 2003 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/isa/isa.h"
#include "hw/i386/pc.h"
#include "hw/input/ps2.h"
#include "sysemu/sysemu.h"

/* debug PC keyboard */
//#define DEBUG_KBD
#ifdef DEBUG_KBD
#define DPRINTF(fmt, ...)                                       \
    do { printf("KBD: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...)
#endif

/*      Keyboard Controller Commands */
#define KBD_CCMD_READ_MODE      0x20    /* Read mode bits */
#define KBD_CCMD_WRITE_MODE     0x60    /* Write mode bits */
#define KBD_CCMD_GET_VERSION    0xA1    /* Get controller version */
#define KBD_CCMD_MOUSE_DISABLE  0xA7    /* Disable mouse interface */
#define KBD_CCMD_MOUSE_ENABLE   0xA8    /* Enable mouse interface */
#define KBD_CCMD_TEST_MOUSE     0xA9    /* Mouse interface test */
#define KBD_CCMD_SELF_TEST      0xAA    /* Controller self test */
#define KBD_CCMD_KBD_TEST       0xAB    /* Keyboard interface test */
#define KBD_CCMD_KBD_DISABLE    0xAD    /* Keyboard interface disable */
#define KBD_CCMD_KBD_ENABLE     0xAE    /* Keyboard interface enable */
#define KBD_CCMD_READ_INPORT    0xC0    /* read input port */
#define KBD_CCMD_READ_OUTPORT   0xD0    /* read output port */
#define KBD_CCMD_WRITE_OUTPORT  0xD1    /* write output port */
#define KBD_CCMD_WRITE_OBUF     0xD2
#define KBD_CCMD_WRITE_AUX_OBUF 0xD3    /* Write to output buffer as if
                                           initiated by the auxiliary device */
#define KBD_CCMD_WRITE_MOUSE    0xD4    /* Write the following byte to the mouse */
#define KBD_CCMD_DISABLE_A20    0xDD    /* HP vectra only ? */
#define KBD_CCMD_ENABLE_A20     0xDF    /* HP vectra only ? */
#define KBD_CCMD_PULSE_BITS_3_0 0xF0    /* Pulse bits 3-0 of the output port P2. */
#define KBD_CCMD_RESET          0xFE    /* Pulse bit 0 of the output port P2 = CPU reset. */
#define KBD_CCMD_NO_OP          0xFF    /* Pulse no bits of the output port P2. */

/* Keyboard Commands */
#define KBD_CMD_SET_LEDS        0xED    /* Set keyboard leds */
#define KBD_CMD_ECHO            0xEE
#define KBD_CMD_GET_ID          0xF2    /* get keyboard ID */
#define KBD_CMD_SET_RATE        0xF3    /* Set typematic rate */
#define KBD_CMD_ENABLE          0xF4    /* Enable scanning */
#define KBD_CMD_RESET_DISABLE   0xF5    /* reset and disable scanning */
#define KBD_CMD_RESET_ENABLE    0xF6    /* reset and enable scanning */
#define KBD_CMD_RESET           0xFF    /* Reset */

/* Keyboard Replies */
#define KBD_REPLY_POR           0xAA    /* Power on reset */
#define KBD_REPLY_ACK           0xFA    /* Command ACK */
#define KBD_REPLY_RESEND        0xFE    /* Command NACK, send the cmd again */

/* Status Register Bits */
#define KBD_STAT_OBF            0x01    /* Keyboard output buffer full */
#define KBD_STAT_IBF            0x02    /* Keyboard input buffer full */
#define KBD_STAT_SELFTEST       0x04    /* Self test successful */
#define KBD_STAT_CMD            0x08    /* Last write was a command write (0=data) */
#define KBD_STAT_UNLOCKED       0x10    /* Zero if keyboard locked */
#define KBD_STAT_MOUSE_OBF      0x20    /* Mouse output buffer full */
#define KBD_STAT_GTO            0x40    /* General receive/xmit timeout */
#define KBD_STAT_PERR           0x80    /* Parity error */

/* Controller Mode Register Bits */
#define KBD_MODE_KBD_INT        0x01    /* Keyboard data generate IRQ1 */
#define KBD_MODE_MOUSE_INT      0x02    /* Mouse data generate IRQ12 */
#define KBD_MODE_SYS            0x04    /* The system flag (?) */
#define KBD_MODE_NO_KEYLOCK     0x08    /* The keylock doesn't affect the keyboard if set */
#define KBD_MODE_DISABLE_KBD    0x10    /* Disable keyboard interface */
#define KBD_MODE_DISABLE_MOUSE  0x20    /* Disable mouse interface */
#define KBD_MODE_KCC            0x40    /* Scan code conversion to PC format */
#define KBD_MODE_RFU            0x80

/* Output Port Bits */
#define KBD_OUT_RESET           0x01    /* 1=normal mode, 0=reset */
#define KBD_OUT_A20             0x02    /* x86 only */
#define KBD_OUT_OBF             0x10    /* Keyboard output buffer full */
#define KBD_OUT_MOUSE_OBF       0x20    /* Mouse output buffer full */

/* OSes typically write 0xdd/0xdf to turn the A20 line off and on.
 * We make the default value of the outport include these four bits,
 * so that the subsection is rarely necessary.
 */
#define KBD_OUT_ONES            0xcc

/* Mouse Commands */
#define AUX_SET_SCALE11         0xE6    /* Set 1:1 scaling */
#define AUX_SET_SCALE21         0xE7    /* Set 2:1 scaling */
#define AUX_SET_RES             0xE8    /* Set resolution */
#define AUX_GET_SCALE           0xE9    /* Get scaling factor */
#define AUX_SET_STREAM          0xEA    /* Set stream mode */
#define AUX_POLL                0xEB    /* Poll */
#define AUX_RESET_WRAP          0xEC    /* Reset wrap mode */
#define AUX_SET_WRAP            0xEE    /* Set wrap mode */
#define AUX_SET_REMOTE          0xF0    /* Set remote mode */
#define AUX_GET_TYPE            0xF2    /* Get type */
#define AUX_SET_SAMPLE          0xF3    /* Set sample rate */
#define AUX_ENABLE_DEV          0xF4    /* Enable aux device */
#define AUX_DISABLE_DEV         0xF5    /* Disable aux device */
#define AUX_SET_DEFAULT         0xF6
#define AUX_RESET               0xFF    /* Reset aux device */
#define AUX_ACK                 0xFA    /* Command byte ACK. */

#define MOUSE_STATUS_REMOTE     0x40
#define MOUSE_STATUS_ENABLED    0x20
#define MOUSE_STATUS_SCALE21    0x10

#define KBD_PENDING_KBD         1
#define KBD_PENDING_AUX         2

typedef struct KBDState {
    uint8_t write_cmd; /* if non zero, write data to port 60 is expected */
    uint8_t status;
    uint8_t mode;
    uint8_t outport;
    bool outport_present;
    /* Bitmask of devices with data available.  */
    uint8_t pending;
    void *kbd;
    void *mouse;

    qemu_irq irq_kbd;
    qemu_irq irq_mouse;
    qemu_irq *a20_out;
    hwaddr mask;
} KBDState;

/* update irq and KBD_STAT_[MOUSE_]OBF */
/* XXX: not generating the irqs if KBD_MODE_DISABLE_KBD is set may be
   incorrect, but it avoids having to simulate exact delays */
static void kbd_update_irq(KBDState *s)
{
    int irq_kbd_level, irq_mouse_level;

    irq_kbd_level = 0;
    irq_mouse_level = 0;
    s->status &= ~(KBD_STAT_OBF | KBD_STAT_MOUSE_OBF);
    s->outport &= ~(KBD_OUT_OBF | KBD_OUT_MOUSE_OBF);
    if (s->pending) {
        s->status |= KBD_STAT_OBF;
        s->outport |= KBD_OUT_OBF;
        /* kbd data takes priority over aux data.  */
        if (s->pending == KBD_PENDING_AUX) {
            s->status |= KBD_STAT_MOUSE_OBF;
            s->outport |= KBD_OUT_MOUSE_OBF;
            if (s->mode & KBD_MODE_MOUSE_INT)
                irq_mouse_level = 1;
        } else {
            if ((s->mode & KBD_MODE_KBD_INT) &&
                !(s->mode & KBD_MODE_DISABLE_KBD))
                irq_kbd_level = 1;
        }
    }
    qemu_set_irq(s->irq_kbd, irq_kbd_level);
    qemu_set_irq(s->irq_mouse, irq_mouse_level);
}

static void kbd_update_kbd_irq(void *opaque, int level)
{
    KBDState *s = (KBDState *)opaque;

    if (level)
        s->pending |= KBD_PENDING_KBD;
    else
        s->pending &= ~KBD_PENDING_KBD;
    kbd_update_irq(s);
}

static void kbd_update_aux_irq(void *opaque, int level)
{
    KBDState *s = (KBDState *)opaque;

    if (level)
        s->pending |= KBD_PENDING_AUX;
    else
        s->pending &= ~KBD_PENDING_AUX;
    kbd_update_irq(s);
}

static uint64_t kbd_read_status(void *opaque, hwaddr addr,
                                unsigned size)
{
    KBDState *s = opaque;
    int val;
    val = s->status;
    DPRINTF("kbd: read status=0x%02x\n", val);
    return val;
}

static void kbd_queue(KBDState *s, int b, int aux)
{
    if (aux)
        ps2_queue(s->mouse, b);
    else
        ps2_queue(s->kbd, b);
}

static void outport_write(KBDState *s, uint32_t val)
{
    DPRINTF("kbd: write outport=0x%02x\n", val);
    s->outport = val;
    if (s->a20_out) {
        qemu_set_irq(*s->a20_out, (val >> 1) & 1);
    }
    if (!(val & 1)) {
        qemu_system_reset_request();
    }
}

static void kbd_write_command(void *opaque, hwaddr addr,
                              uint64_t val, unsigned size)
{
    KBDState *s = opaque;

    DPRINTF("kbd: write cmd=0x%02" PRIx64 "\n", val);

    /* Bits 3-0 of the output port P2 of the keyboard controller may be pulsed
     * low for approximately 6 micro seconds. Bits 3-0 of the KBD_CCMD_PULSE
     * command specify the output port bits to be pulsed.
     * 0: Bit should be pulsed. 1: Bit should not be modified.
     * The only useful version of this command is pulsing bit 0,
     * which does a CPU reset.
     */
    if((val & KBD_CCMD_PULSE_BITS_3_0) == KBD_CCMD_PULSE_BITS_3_0) {
        if(!(val & 1))
            val = KBD_CCMD_RESET;
        else
            val = KBD_CCMD_NO_OP;
    }

    switch(val) {
    case KBD_CCMD_READ_MODE:
        kbd_queue(s, s->mode, 0);
        break;
    case KBD_CCMD_WRITE_MODE:
    case KBD_CCMD_WRITE_OBUF:
    case KBD_CCMD_WRITE_AUX_OBUF:
    case KBD_CCMD_WRITE_MOUSE:
    case KBD_CCMD_WRITE_OUTPORT:
        s->write_cmd = val;
        break;
    case KBD_CCMD_MOUSE_DISABLE:
        s->mode |= KBD_MODE_DISABLE_MOUSE;
        break;
    case KBD_CCMD_MOUSE_ENABLE:
        s->mode &= ~KBD_MODE_DISABLE_MOUSE;
        break;
    case KBD_CCMD_TEST_MOUSE:
        kbd_queue(s, 0x00, 0);
        break;
    case KBD_CCMD_SELF_TEST:
        s->status |= KBD_STAT_SELFTEST;
        kbd_queue(s, 0x55, 0);
        break;
    case KBD_CCMD_KBD_TEST:
        kbd_queue(s, 0x00, 0);
        break;
    case KBD_CCMD_KBD_DISABLE:
        s->mode |= KBD_MODE_DISABLE_KBD;
        kbd_update_irq(s);
        break;
    case KBD_CCMD_KBD_ENABLE:
        s->mode &= ~KBD_MODE_DISABLE_KBD;
        kbd_update_irq(s);
        break;
    case KBD_CCMD_READ_INPORT:
        kbd_queue(s, 0x80, 0);
        break;
    case KBD_CCMD_READ_OUTPORT:
        kbd_queue(s, s->outport, 0);
        break;
    case KBD_CCMD_ENABLE_A20:
        if (s->a20_out) {
            qemu_irq_raise(*s->a20_out);
        }
        s->outport |= KBD_OUT_A20;
        break;
    case KBD_CCMD_DISABLE_A20:
        if (s->a20_out) {
            qemu_irq_lower(*s->a20_out);
        }
        s->outport &= ~KBD_OUT_A20;
        break;
    case KBD_CCMD_RESET:
        qemu_system_reset_request();
        break;
    case KBD_CCMD_NO_OP:
        /* ignore that */
        break;
    default:
        fprintf(stderr, "qemu: unsupported keyboard cmd=0x%02x\n", (int)val);
        break;
    }
}

static uint64_t kbd_read_data(void *opaque, hwaddr addr,
                              unsigned size)
{
    KBDState *s = opaque;
    uint32_t val;

    if (s->pending == KBD_PENDING_AUX)
        val = ps2_read_data(s->mouse);
    else
        val = ps2_read_data(s->kbd);

    DPRINTF("kbd: read data=0x%02x\n", val);
    return val;
}

static void kbd_write_data(void *opaque, hwaddr addr,
                           uint64_t val, unsigned size)
{
    KBDState *s = opaque;

    DPRINTF("kbd: write data=0x%02" PRIx64 "\n", val);

    switch(s->write_cmd) {
    case 0:
        ps2_write_keyboard(s->kbd, val);
        break;
    case KBD_CCMD_WRITE_MODE:
        s->mode = val;
        ps2_keyboard_set_translation(s->kbd, (s->mode & KBD_MODE_KCC) != 0);
        /* ??? */
        kbd_update_irq(s);
        break;
    case KBD_CCMD_WRITE_OBUF:
        kbd_queue(s, val, 0);
        break;
    case KBD_CCMD_WRITE_AUX_OBUF:
        kbd_queue(s, val, 1);
        break;
    case KBD_CCMD_WRITE_OUTPORT:
        outport_write(s, val);
        break;
    case KBD_CCMD_WRITE_MOUSE:
        ps2_write_mouse(s->mouse, val);
        break;
    default:
        break;
    }
    s->write_cmd = 0;
}

static void kbd_reset(void *opaque)
{
    KBDState *s = opaque;

    s->mode = KBD_MODE_KBD_INT | KBD_MODE_MOUSE_INT;
    s->status = KBD_STAT_CMD | KBD_STAT_UNLOCKED;
    s->outport = KBD_OUT_RESET | KBD_OUT_A20 | KBD_OUT_ONES;
    s->outport_present = false;
}

static uint8_t kbd_outport_default(KBDState *s)
{
    return KBD_OUT_RESET | KBD_OUT_A20 | KBD_OUT_ONES
           | (s->status & KBD_STAT_OBF ? KBD_OUT_OBF : 0)
           | (s->status & KBD_STAT_MOUSE_OBF ? KBD_OUT_MOUSE_OBF : 0);
}

static int kbd_outport_post_load(void *opaque, int version_id)
{
    KBDState *s = opaque;
    s->outport_present = true;
    return 0;
}

static bool kbd_outport_needed(void *opaque)
{
    KBDState *s = opaque;
    return s->outport != kbd_outport_default(s);
}

static const VMStateDescription vmstate_kbd_outport = {
    .name = "pckbd_outport",
    .version_id = 1,
    .minimum_version_id = 1,
    .post_load = kbd_outport_post_load,
    .needed = kbd_outport_needed,
    .fields = (VMStateField[]) {
        VMSTATE_UINT8(outport, KBDState),
        VMSTATE_END_OF_LIST()
    }
};

static int kbd_post_load(void *opaque, int version_id)
{
    KBDState *s = opaque;
    if (!s->outport_present) {
        s->outport = kbd_outport_default(s);
    }
    s->outport_present = false;
    return 0;
}

static const VMStateDescription vmstate_kbd = {
    .name = "pckbd",
    .version_id = 3,
    .minimum_version_id = 3,
    .post_load = kbd_post_load,
    .fields = (VMStateField[]) {
        VMSTATE_UINT8(write_cmd, KBDState),
        VMSTATE_UINT8(status, KBDState),
        VMSTATE_UINT8(mode, KBDState),
        VMSTATE_UINT8(pending, KBDState),
        VMSTATE_END_OF_LIST()
    },
    .subsections = (const VMStateDescription*[]) {
        &vmstate_kbd_outport,
        NULL
    }
};

/* Memory mapped interface */
static uint32_t kbd_mm_readb (void *opaque, hwaddr addr)
{
    KBDState *s = opaque;

    if (addr & s->mask)
        return kbd_read_status(s, 0, 1) & 0xff;
    else
        return kbd_read_data(s, 0, 1) & 0xff;
}

static void kbd_mm_writeb (void *opaque, hwaddr addr, uint32_t value)
{
    KBDState *s = opaque;

    if (addr & s->mask)
        kbd_write_command(s, 0, value & 0xff, 1);
    else
        kbd_write_data(s, 0, value & 0xff, 1);
}

static const MemoryRegionOps i8042_mmio_ops = {
    .endianness = DEVICE_NATIVE_ENDIAN,
    .old_mmio = {
        .read = { kbd_mm_readb, kbd_mm_readb, kbd_mm_readb },
        .write = { kbd_mm_writeb, kbd_mm_writeb, kbd_mm_writeb },
    },
};

void i8042_mm_init(qemu_irq kbd_irq, qemu_irq mouse_irq,
                   MemoryRegion *region, ram_addr_t size,
                   hwaddr mask)
{
    KBDState *s = g_malloc0(sizeof(KBDState));

    s->irq_kbd = kbd_irq;
    s->irq_mouse = mouse_irq;
    s->mask = mask;

    vmstate_register(NULL, 0, &vmstate_kbd, s);

    memory_region_init_io(region, NULL, &i8042_mmio_ops, s, "i8042", size);

    s->kbd = ps2_kbd_init(kbd_update_kbd_irq, s);
    s->mouse = ps2_mouse_init(kbd_update_aux_irq, s);
    qemu_register_reset(kbd_reset, s);
}

#define TYPE_I8042 "i8042"
#define I8042(obj) OBJECT_CHECK(ISAKBDState, (obj), TYPE_I8042)

typedef struct ISAKBDState {
    ISADevice parent_obj;

    KBDState kbd;
    MemoryRegion io[2];
} ISAKBDState;

void i8042_isa_mouse_fake_event(void *opaque)
{
    ISADevice *dev = opaque;
    ISAKBDState *isa = I8042(dev);
    KBDState *s = &isa->kbd;

    ps2_mouse_fake_event(s->mouse);
}

void i8042_setup_a20_line(ISADevice *dev, qemu_irq *a20_out)
{
    ISAKBDState *isa = I8042(dev);
    KBDState *s = &isa->kbd;

    s->a20_out = a20_out;
}

static const VMStateDescription vmstate_kbd_isa = {
    .name = "pckbd",
    .version_id = 3,
    .minimum_version_id = 3,
    .fields = (VMStateField[]) {
        VMSTATE_STRUCT(kbd, ISAKBDState, 0, vmstate_kbd, KBDState),
        VMSTATE_END_OF_LIST()
    }
};

static const MemoryRegionOps i8042_data_ops = {
    .read = kbd_read_data,
    .write = kbd_write_data,
    .impl = {
        .min_access_size = 1,
        .max_access_size = 1,
    },
    .endianness = DEVICE_LITTLE_ENDIAN,
};

static const MemoryRegionOps i8042_cmd_ops = {
    .read = kbd_read_status,
    .write = kbd_write_command,
    .impl = {
        .min_access_size = 1,
        .max_access_size = 1,
    },
    .endianness = DEVICE_LITTLE_ENDIAN,
};

static void i8042_initfn(Object *obj)
{
    ISAKBDState *isa_s = I8042(obj);
    KBDState *s = &isa_s->kbd;

    memory_region_init_io(isa_s->io + 0, obj, &i8042_data_ops, s,
                          "i8042-data", 1);
    memory_region_init_io(isa_s->io + 1, obj, &i8042_cmd_ops, s,
                          "i8042-cmd", 1);
}

static void i8042_realizefn(DeviceState *dev, Error **errp)
{
    ISADevice *isadev = ISA_DEVICE(dev);
    ISAKBDState *isa_s = I8042(dev);
    KBDState *s = &isa_s->kbd;

    isa_init_irq(isadev, &s->irq_kbd, 1);
    isa_init_irq(isadev, &s->irq_mouse, 12);

    isa_register_ioport(isadev, isa_s->io + 0, 0x60);
    isa_register_ioport(isadev, isa_s->io + 1, 0x64);

    s->kbd = ps2_kbd_init(kbd_update_kbd_irq, s);
    s->mouse = ps2_mouse_init(kbd_update_aux_irq, s);
    qemu_register_reset(kbd_reset, s);
}

static void i8042_class_initfn(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);

    dc->realize = i8042_realizefn;
    dc->vmsd = &vmstate_kbd_isa;
}

static const TypeInfo i8042_info = {
    .name          = TYPE_I8042,
    .parent        = TYPE_ISA_DEVICE,
    .instance_size = sizeof(ISAKBDState),
    .instance_init = i8042_initfn,
    .class_init    = i8042_class_initfn,
};

static void i8042_register_types(void)
{
    type_register_static(&i8042_info);
}

type_init(i8042_register_types)