gwj / at91sam9263 · Files

/*

 * QEMU ESCC (Z8030/Z8530/Z85C30/SCC/ESCC) serial port emulation

 *

 * Copyright (c) 2003-2005 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 "hw.h"

#include "sysbus.h"

#include "escc.h"

#include "qemu-char.h"
#include "console.h"

/* debug serial */

//#define DEBUG_SERIAL

/* debug keyboard */
//#define DEBUG_KBD

/* debug mouse */

//#define DEBUG_MOUSE

/*

 * On Sparc32 this is the serial port, mouse and keyboard part of chip STP2001

 * (Slave I/O), also produced as NCR89C105. See
 * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C105.txt

 *

 * The serial ports implement full AMD AM8530 or Zilog Z8530 chips,
 * mouse and keyboard ports don't implement all functions and they are
 * only asynchronous. There is no DMA.
 *

 * Z85C30 is also used on PowerMacs. There are some small differences
 * between Sparc version (sunzilog) and PowerMac (pmac):
 *  Offset between control and data registers
 *  There is some kind of lockup bug, but we can ignore it
 *  CTS is inverted
 *  DMA on pmac using DBDMA chip
 *  pmac can do IRDA and faster rates, sunzilog can only do 38400
 *  pmac baud rate generator clock is 3.6864 MHz, sunzilog 4.9152 MHz

 */

/*
 * Modifications:
 *  2006-Aug-10  Igor Kovalenko :   Renamed KBDQueue to SERIOQueue, implemented
 *                                  serial mouse queue.
 *                                  Implemented serial mouse protocol.
 */

#ifdef DEBUG_SERIAL

#define SER_DPRINTF(fmt, ...)                                   \
    do { printf("SER: " fmt , ## __VA_ARGS__); } while (0)

#else

#define SER_DPRINTF(fmt, ...)

#endif
#ifdef DEBUG_KBD

#define KBD_DPRINTF(fmt, ...)                                   \
    do { printf("KBD: " fmt , ## __VA_ARGS__); } while (0)

#else

#define KBD_DPRINTF(fmt, ...)

#endif
#ifdef DEBUG_MOUSE

#define MS_DPRINTF(fmt, ...)                                    \
    do { printf("MSC: " fmt , ## __VA_ARGS__); } while (0)

#else

#define MS_DPRINTF(fmt, ...)

#endif

typedef enum {
    chn_a, chn_b,
} chn_id_t;

#define CHN_C(s) ((s)->chn == chn_b? 'b' : 'a')

typedef enum {
    ser, kbd, mouse,
} chn_type_t;

#define SERIO_QUEUE_SIZE 256

typedef struct {

    uint8_t data[SERIO_QUEUE_SIZE];

    int rptr, wptr, count;

} SERIOQueue;

#define SERIAL_REGS 16

typedef struct ChannelState {

    qemu_irq irq;

    uint32_t reg;
    uint32_t rxint, txint, rxint_under_svc, txint_under_svc;

    chn_id_t chn; // this channel, A (base+4) or B (base+0)
    chn_type_t type;
    struct ChannelState *otherchn;

    uint8_t rx, tx, wregs[SERIAL_REGS], rregs[SERIAL_REGS];

    SERIOQueue queue;

    CharDriverState *chr;

    int e0_mode, led_mode, caps_lock_mode, num_lock_mode;

    int disabled;

    int clock;

} ChannelState;

struct SerialState {

    SysBusDevice busdev;

    struct ChannelState chn[2];

    int it_shift;

    int mmio_index;

    uint32_t disabled;
    uint32_t frequency;

};

#define SERIAL_CTRL 0
#define SERIAL_DATA 1

#define W_CMD     0
#define CMD_PTR_MASK   0x07
#define CMD_CMD_MASK   0x38
#define CMD_HI         0x08
#define CMD_CLR_TXINT  0x28
#define CMD_CLR_IUS    0x38
#define W_INTR    1
#define INTR_INTALL    0x01
#define INTR_TXINT     0x02
#define INTR_RXMODEMSK 0x18
#define INTR_RXINT1ST  0x08
#define INTR_RXINTALL  0x10
#define W_IVEC    2
#define W_RXCTRL  3
#define RXCTRL_RXEN    0x01
#define W_TXCTRL1 4
#define TXCTRL1_PAREN  0x01
#define TXCTRL1_PAREV  0x02
#define TXCTRL1_1STOP  0x04
#define TXCTRL1_1HSTOP 0x08
#define TXCTRL1_2STOP  0x0c
#define TXCTRL1_STPMSK 0x0c
#define TXCTRL1_CLK1X  0x00
#define TXCTRL1_CLK16X 0x40
#define TXCTRL1_CLK32X 0x80
#define TXCTRL1_CLK64X 0xc0
#define TXCTRL1_CLKMSK 0xc0
#define W_TXCTRL2 5
#define TXCTRL2_TXEN   0x08
#define TXCTRL2_BITMSK 0x60
#define TXCTRL2_5BITS  0x00
#define TXCTRL2_7BITS  0x20
#define TXCTRL2_6BITS  0x40
#define TXCTRL2_8BITS  0x60
#define W_SYNC1   6
#define W_SYNC2   7
#define W_TXBUF   8
#define W_MINTR   9
#define MINTR_STATUSHI 0x10
#define MINTR_RST_MASK 0xc0
#define MINTR_RST_B    0x40
#define MINTR_RST_A    0x80
#define MINTR_RST_ALL  0xc0
#define W_MISC1  10
#define W_CLOCK  11
#define CLOCK_TRXC     0x08
#define W_BRGLO  12
#define W_BRGHI  13
#define W_MISC2  14
#define MISC2_PLLDIS   0x30
#define W_EXTINT 15
#define EXTINT_DCD     0x08
#define EXTINT_SYNCINT 0x10
#define EXTINT_CTSINT  0x20
#define EXTINT_TXUNDRN 0x40
#define EXTINT_BRKINT  0x80

#define R_STATUS  0
#define STATUS_RXAV    0x01
#define STATUS_ZERO    0x02
#define STATUS_TXEMPTY 0x04
#define STATUS_DCD     0x08
#define STATUS_SYNC    0x10
#define STATUS_CTS     0x20
#define STATUS_TXUNDRN 0x40
#define STATUS_BRK     0x80
#define R_SPEC    1
#define SPEC_ALLSENT   0x01
#define SPEC_BITS8     0x06
#define R_IVEC    2
#define IVEC_TXINTB    0x00
#define IVEC_LONOINT   0x06
#define IVEC_LORXINTA  0x0c
#define IVEC_LORXINTB  0x04
#define IVEC_LOTXINTA  0x08
#define IVEC_HINOINT   0x60
#define IVEC_HIRXINTA  0x30
#define IVEC_HIRXINTB  0x20
#define IVEC_HITXINTA  0x10
#define R_INTR    3
#define INTR_EXTINTB   0x01
#define INTR_TXINTB    0x02
#define INTR_RXINTB    0x04
#define INTR_EXTINTA   0x08
#define INTR_TXINTA    0x10
#define INTR_RXINTA    0x20
#define R_IPEN    4
#define R_TXCTRL1 5
#define R_TXCTRL2 6
#define R_BC      7
#define R_RXBUF   8
#define R_RXCTRL  9
#define R_MISC   10
#define R_MISC1  11
#define R_BRGLO  12
#define R_BRGHI  13
#define R_MISC1I 14
#define R_EXTINT 15

static void handle_kbd_command(ChannelState *s, int val);
static int serial_can_receive(void *opaque);
static void serial_receive_byte(ChannelState *s, int ch);

static void clear_queue(void *opaque)
{
    ChannelState *s = opaque;
    SERIOQueue *q = &s->queue;
    q->rptr = q->wptr = q->count = 0;
}

static void put_queue(void *opaque, int b)
{
    ChannelState *s = opaque;

    SERIOQueue *q = &s->queue;

    SER_DPRINTF("channel %c put: 0x%02x\n", CHN_C(s), b);

    if (q->count >= SERIO_QUEUE_SIZE)

        return;
    q->data[q->wptr] = b;

    if (++q->wptr == SERIO_QUEUE_SIZE)

        q->wptr = 0;
    q->count++;
    serial_receive_byte(s, 0);
}

static uint32_t get_queue(void *opaque)
{
    ChannelState *s = opaque;

    SERIOQueue *q = &s->queue;

    int val;

    if (q->count == 0) {

        return 0;

    } else {
        val = q->data[q->rptr];

        if (++q->rptr == SERIO_QUEUE_SIZE)

            q->rptr = 0;
        q->count--;
    }

    SER_DPRINTF("channel %c get 0x%02x\n", CHN_C(s), val);

    if (q->count > 0)

        serial_receive_byte(s, 0);

    return val;
}

static int escc_update_irq_chn(ChannelState *s)

{

    if ((((s->wregs[W_INTR] & INTR_TXINT) && s->txint == 1) ||

         // tx ints enabled, pending
         ((((s->wregs[W_INTR] & INTR_RXMODEMSK) == INTR_RXINT1ST) ||
           ((s->wregs[W_INTR] & INTR_RXMODEMSK) == INTR_RXINTALL)) &&

          s->rxint == 1) || // rx ints enabled, pending

         ((s->wregs[W_EXTINT] & EXTINT_BRKINT) &&
          (s->rregs[R_STATUS] & STATUS_BRK)))) { // break int e&p

        return 1;

    }

    return 0;
}

static void escc_update_irq(ChannelState *s)

{
    int irq;

    irq = escc_update_irq_chn(s);
    irq |= escc_update_irq_chn(s->otherchn);

    SER_DPRINTF("IRQ = %d\n", irq);
    qemu_set_irq(s->irq, irq);

}

static void escc_reset_chn(ChannelState *s)

{
    int i;

    s->reg = 0;

    for (i = 0; i < SERIAL_REGS; i++) {

        s->rregs[i] = 0;
        s->wregs[i] = 0;

    }

    s->wregs[W_TXCTRL1] = TXCTRL1_1STOP; // 1X divisor, 1 stop bit, no parity
    s->wregs[W_MINTR] = MINTR_RST_ALL;
    s->wregs[W_CLOCK] = CLOCK_TRXC; // Synch mode tx clock = TRxC
    s->wregs[W_MISC2] = MISC2_PLLDIS; // PLL disabled
    s->wregs[W_EXTINT] = EXTINT_DCD | EXTINT_SYNCINT | EXTINT_CTSINT |
        EXTINT_TXUNDRN | EXTINT_BRKINT; // Enable most interrupts

    if (s->disabled)

        s->rregs[R_STATUS] = STATUS_TXEMPTY | STATUS_DCD | STATUS_SYNC |
            STATUS_CTS | STATUS_TXUNDRN;

    else

        s->rregs[R_STATUS] = STATUS_TXEMPTY | STATUS_TXUNDRN;

    s->rregs[R_SPEC] = SPEC_BITS8 | SPEC_ALLSENT;

    s->rx = s->tx = 0;
    s->rxint = s->txint = 0;

    s->rxint_under_svc = s->txint_under_svc = 0;

    s->e0_mode = s->led_mode = s->caps_lock_mode = s->num_lock_mode = 0;

    clear_queue(s);

}

static void escc_reset(void *opaque)

{
    SerialState *s = opaque;

    escc_reset_chn(&s->chn[0]);
    escc_reset_chn(&s->chn[1]);

}

static inline void set_rxint(ChannelState *s)
{
    s->rxint = 1;

    if (!s->txint_under_svc) {
        s->rxint_under_svc = 1;

        if (s->chn == chn_a) {

            if (s->wregs[W_MINTR] & MINTR_STATUSHI)
                s->otherchn->rregs[R_IVEC] = IVEC_HIRXINTA;

            else

                s->otherchn->rregs[R_IVEC] = IVEC_LORXINTA;

        } else {

            if (s->wregs[W_MINTR] & MINTR_STATUSHI)
                s->rregs[R_IVEC] = IVEC_HIRXINTB;

            else

                s->rregs[R_IVEC] = IVEC_LORXINTB;

        }

    }

    if (s->chn == chn_a)

        s->rregs[R_INTR] |= INTR_RXINTA;

    else

        s->otherchn->rregs[R_INTR] |= INTR_RXINTB;

    escc_update_irq(s);

}

static inline void set_txint(ChannelState *s)
{
    s->txint = 1;
    if (!s->rxint_under_svc) {
        s->txint_under_svc = 1;
        if (s->chn == chn_a) {
            if (s->wregs[W_MINTR] & MINTR_STATUSHI)
                s->otherchn->rregs[R_IVEC] = IVEC_HITXINTA;
            else
                s->otherchn->rregs[R_IVEC] = IVEC_LOTXINTA;
        } else {
            s->rregs[R_IVEC] = IVEC_TXINTB;
        }
    }
    if (s->chn == chn_a)
        s->rregs[R_INTR] |= INTR_TXINTA;
    else
        s->otherchn->rregs[R_INTR] |= INTR_TXINTB;

    escc_update_irq(s);

}

static inline void clr_rxint(ChannelState *s)
{
    s->rxint = 0;
    s->rxint_under_svc = 0;
    if (s->chn == chn_a) {
        if (s->wregs[W_MINTR] & MINTR_STATUSHI)
            s->otherchn->rregs[R_IVEC] = IVEC_HINOINT;
        else
            s->otherchn->rregs[R_IVEC] = IVEC_LONOINT;
        s->rregs[R_INTR] &= ~INTR_RXINTA;
    } else {
        if (s->wregs[W_MINTR] & MINTR_STATUSHI)
            s->rregs[R_IVEC] = IVEC_HINOINT;
        else
            s->rregs[R_IVEC] = IVEC_LONOINT;
        s->otherchn->rregs[R_INTR] &= ~INTR_RXINTB;
    }
    if (s->txint)
        set_txint(s);

    escc_update_irq(s);

}

static inline void clr_txint(ChannelState *s)
{
    s->txint = 0;

    s->txint_under_svc = 0;

    if (s->chn == chn_a) {

        if (s->wregs[W_MINTR] & MINTR_STATUSHI)
            s->otherchn->rregs[R_IVEC] = IVEC_HINOINT;

        else

            s->otherchn->rregs[R_IVEC] = IVEC_LONOINT;
        s->rregs[R_INTR] &= ~INTR_TXINTA;

    } else {

        if (s->wregs[W_MINTR] & MINTR_STATUSHI)
            s->rregs[R_IVEC] = IVEC_HINOINT;

        else

            s->rregs[R_IVEC] = IVEC_LONOINT;
        s->otherchn->rregs[R_INTR] &= ~INTR_TXINTB;

    }

    if (s->rxint)
        set_rxint(s);

    escc_update_irq(s);

}

static void escc_update_parameters(ChannelState *s)

{
    int speed, parity, data_bits, stop_bits;
    QEMUSerialSetParams ssp;

    if (!s->chr || s->type != ser)
        return;

    if (s->wregs[W_TXCTRL1] & TXCTRL1_PAREN) {
        if (s->wregs[W_TXCTRL1] & TXCTRL1_PAREV)

            parity = 'E';
        else
            parity = 'O';
    } else {
        parity = 'N';
    }

    if ((s->wregs[W_TXCTRL1] & TXCTRL1_STPMSK) == TXCTRL1_2STOP)

        stop_bits = 2;
    else
        stop_bits = 1;

    switch (s->wregs[W_TXCTRL2] & TXCTRL2_BITMSK) {
    case TXCTRL2_5BITS:

        data_bits = 5;
        break;

    case TXCTRL2_7BITS:

        data_bits = 7;
        break;

    case TXCTRL2_6BITS:

        data_bits = 6;
        break;
    default:

    case TXCTRL2_8BITS:

        data_bits = 8;
        break;
    }

    speed = s->clock / ((s->wregs[W_BRGLO] | (s->wregs[W_BRGHI] << 8)) + 2);

    switch (s->wregs[W_TXCTRL1] & TXCTRL1_CLKMSK) {
    case TXCTRL1_CLK1X:

        break;

    case TXCTRL1_CLK16X:

        speed /= 16;
        break;

    case TXCTRL1_CLK32X:

        speed /= 32;
        break;
    default:

    case TXCTRL1_CLK64X:

        speed /= 64;
        break;
    }
    ssp.speed = speed;
    ssp.parity = parity;
    ssp.data_bits = data_bits;
    ssp.stop_bits = stop_bits;
    SER_DPRINTF("channel %c: speed=%d parity=%c data=%d stop=%d\n", CHN_C(s),
                speed, parity, data_bits, stop_bits);
    qemu_chr_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp);
}

static void escc_mem_writeb(void *opaque, target_phys_addr_t addr, uint32_t val)

{

    SerialState *serial = opaque;

    ChannelState *s;
    uint32_t saddr;
    int newreg, channel;

    val &= 0xff;

    saddr = (addr >> serial->it_shift) & 1;
    channel = (addr >> (serial->it_shift + 1)) & 1;

    s = &serial->chn[channel];

    switch (saddr) {

    case SERIAL_CTRL:
        SER_DPRINTF("Write channel %c, reg[%d] = %2.2x\n", CHN_C(s), s->reg,
                    val & 0xff);

        newreg = 0;
        switch (s->reg) {

        case W_CMD:
            newreg = val & CMD_PTR_MASK;
            val &= CMD_CMD_MASK;

            switch (val) {

            case CMD_HI:
                newreg |= CMD_HI;

                break;

            case CMD_CLR_TXINT:

                clr_txint(s);

                break;

            case CMD_CLR_IUS:

                if (s->rxint_under_svc)
                    clr_rxint(s);
                else if (s->txint_under_svc)
                    clr_txint(s);

                break;
            default:
                break;
            }
            break;

        case W_INTR ... W_RXCTRL:
        case W_SYNC1 ... W_TXBUF:
        case W_MISC1 ... W_CLOCK:
        case W_MISC2 ... W_EXTINT:

            s->wregs[s->reg] = val;
            break;

        case W_TXCTRL1:
        case W_TXCTRL2:

            s->wregs[s->reg] = val;

            escc_update_parameters(s);

            break;

        case W_BRGLO:
        case W_BRGHI:

            s->wregs[s->reg] = val;

            s->rregs[s->reg] = val;

            escc_update_parameters(s);

            break;

        case W_MINTR:
            switch (val & MINTR_RST_MASK) {

            case 0:
            default:
                break;

            case MINTR_RST_B:

                escc_reset_chn(&serial->chn[0]);

                return;

            case MINTR_RST_A:

                escc_reset_chn(&serial->chn[1]);

                return;

            case MINTR_RST_ALL:

                escc_reset(serial);

                return;
            }
            break;
        default:
            break;
        }
        if (s->reg == 0)
            s->reg = newreg;
        else
            s->reg = 0;
        break;

    case SERIAL_DATA:

        SER_DPRINTF("Write channel %c, ch %d\n", CHN_C(s), val);

        s->tx = val;

        if (s->wregs[W_TXCTRL2] & TXCTRL2_TXEN) { // tx enabled

            if (s->chr)
                qemu_chr_write(s->chr, &s->tx, 1);

            else if (s->type == kbd && !s->disabled) {

                handle_kbd_command(s, val);
            }
        }

        s->rregs[R_STATUS] |= STATUS_TXEMPTY; // Tx buffer empty
        s->rregs[R_SPEC] |= SPEC_ALLSENT; // All sent

        set_txint(s);

        break;

    default:

        break;

    }
}

static uint32_t escc_mem_readb(void *opaque, target_phys_addr_t addr)

{

    SerialState *serial = opaque;

    ChannelState *s;
    uint32_t saddr;
    uint32_t ret;
    int channel;

    saddr = (addr >> serial->it_shift) & 1;
    channel = (addr >> (serial->it_shift + 1)) & 1;

    s = &serial->chn[channel];

    switch (saddr) {

    case SERIAL_CTRL:
        SER_DPRINTF("Read channel %c, reg[%d] = %2.2x\n", CHN_C(s), s->reg,
                    s->rregs[s->reg]);

        ret = s->rregs[s->reg];
        s->reg = 0;
        return ret;

    case SERIAL_DATA:
        s->rregs[R_STATUS] &= ~STATUS_RXAV;

        clr_rxint(s);

        if (s->type == kbd || s->type == mouse)
            ret = get_queue(s);
        else
            ret = s->rx;
        SER_DPRINTF("Read channel %c, ch %d\n", CHN_C(s), ret);

        if (s->chr)
            qemu_chr_accept_input(s->chr);

        return ret;

    default:

        break;