Archipelago » qemu

/*

 * QEMU ETRAX System Emulator

 *

 * Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.

 *

 * 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 <stdio.h>

#include <ctype.h>

#include "hw.h"

#include "qemu-char.h"

#define D(x)

#define RW_TR_CTRL     0x00

#define RW_TR_DMA_EN   0x04

#define RW_REC_CTRL    0x08

#define RW_DOUT        0x1c

#define RS_STAT_DIN    0x20

#define R_STAT_DIN     0x24

#define RW_INTR_MASK   0x2c

#define RW_ACK_INTR    0x30

#define R_INTR         0x34

#define R_MASKED_INTR  0x38

#define STAT_DAV     16

#define STAT_TR_IDLE 22

#define STAT_TR_RDY  24

struct etrax_serial_t

{

        CPUState *env;

        CharDriverState *chr;

        qemu_irq *irq;

        int pending_tx;

        /* Control registers.  */

        uint32_t rw_tr_ctrl;

        uint32_t rw_tr_dma_en;

        uint32_t rw_rec_ctrl;

        uint32_t rs_stat_din;

        uint32_t r_stat_din;

        uint32_t rw_intr_mask;

        uint32_t rw_ack_intr;

        uint32_t r_intr;

        uint32_t r_masked_intr;

};

static void ser_update_irq(struct etrax_serial_t *s)

{

        uint32_t o_irq = s->r_masked_intr;

        s->r_intr &= ~(s->rw_ack_intr);

        s->r_masked_intr = s->r_intr & s->rw_intr_mask;

        if (o_irq != s->r_masked_intr) {

                D(printf("irq_mask=%x r_intr=%x rmi=%x airq=%x \n", 

                         s->rw_intr_mask, s->r_intr, 

                         s->r_masked_intr, s->rw_ack_intr));

                if (s->r_masked_intr)

                        qemu_irq_raise(s->irq[0]);

                else

                        qemu_irq_lower(s->irq[0]);

        }

        s->rw_ack_intr = 0;

}

static uint32_t ser_readb (void *opaque, target_phys_addr_t addr)

{

        D(CPUState *env = opaque);

        D(printf ("%s %x\n", __func__, addr));

        return 0;

}

static uint32_t ser_readl (void *opaque, target_phys_addr_t addr)

{

        struct etrax_serial_t *s = opaque;

        D(CPUState *env = s->env);

        uint32_t r = 0;

        switch (addr)

        {

                case RW_TR_CTRL:

                        r = s->rw_tr_ctrl;

                        break;

                case RW_TR_DMA_EN:

                        r = s->rw_tr_dma_en;

                        break;

                case RS_STAT_DIN:

                        r = s->rs_stat_din;

                        /* clear dav.  */

                        s->rs_stat_din &= ~(1 << STAT_DAV);

                        break;

                case R_STAT_DIN:

                        r = s->rs_stat_din;

                        break;

                case RW_ACK_INTR:

                        D(printf("load rw_ack_intr=%x\n", s->rw_ack_intr));

                        r = s->rw_ack_intr;

                        break;

                case RW_INTR_MASK:

                        r = s->rw_intr_mask;

                        break;

                case R_INTR:

                        D(printf("load r_intr=%x\n", s->r_intr));

                        r = s->r_intr;

                        break;

                case R_MASKED_INTR:

                        D(printf("load r_maked_intr=%x\n", s->r_masked_intr));

                        r = s->r_masked_intr;

                        break;

                default:

                        D(printf ("%s %x\n", __func__, addr));

                        break;

        }

        return r;

}

static void

ser_writeb (void *opaque, target_phys_addr_t addr, uint32_t value)

{

        D(struct etrax_serial_t *s = opaque);

        D(CPUState *env = s->env);

         D(printf ("%s %x %x\n", __func__, addr, value));

}

static void

ser_writel (void *opaque, target_phys_addr_t addr, uint32_t value)

{

        struct etrax_serial_t *s = opaque;

        unsigned char ch = value;

        D(CPUState *env = s->env);

        switch (addr)

        {

                case RW_TR_CTRL:

                        D(printf("rw_tr_ctrl=%x\n", value));

                        s->rw_tr_ctrl = value;

                        break;

                case RW_TR_DMA_EN:

                        D(printf("rw_tr_dma_en=%x\n", value));

                        s->rw_tr_dma_en = value;

                        break;

                case RW_DOUT:

                        qemu_chr_write(s->chr, &ch, 1);

                        s->r_intr |= 1;

                        s->pending_tx = 1;

                        break;

                case RW_ACK_INTR:

                        D(printf("rw_ack_intr=%x\n", value));

                        s->rw_ack_intr = value;

                        if (s->pending_tx && (s->rw_ack_intr & 1)) {

                                s->r_intr |= 1;

                                s->pending_tx = 0;

                                s->rw_ack_intr &= ~1;

                        }

                        break;

                case RW_INTR_MASK:

                        D(printf("r_intr_mask=%x\n", value));

                        s->rw_intr_mask = value;

                        break;

                default:

                        D(printf ("%s %x %x\n",  __func__, addr, value));

                        break;

        }

        ser_update_irq(s);

}

static CPUReadMemoryFunc *ser_read[] = {

        &ser_readb,

        &ser_readb,

        &ser_readl,

};

static CPUWriteMemoryFunc *ser_write[] = {

        &ser_writeb,

        &ser_writeb,

        &ser_writel,

};

static void serial_receive(void *opaque, const uint8_t *buf, int size)

{

        struct etrax_serial_t *s = opaque;

        s->r_intr |= 8;

        s->rs_stat_din &= ~0xff;

        s->rs_stat_din |= (buf[0] & 0xff);

        s->rs_stat_din |= (1 << STAT_DAV); /* dav.  */

        ser_update_irq(s);

}

static int serial_can_receive(void *opaque)

{

        struct etrax_serial_t *s = opaque;

        int r;

        /* Is the receiver enabled?  */

        r = s->rw_rec_ctrl & 1;

        /* Pending rx data?  */

        r |= !(s->r_intr & 8);

        return r;

}

static void serial_event(void *opaque, int event)

{

}

void etraxfs_ser_init(CPUState *env, qemu_irq *irq, CharDriverState *chr,

                      target_phys_addr_t base)

{

        struct etrax_serial_t *s;

        int ser_regs;

        s = qemu_mallocz(sizeof *s);

        if (!s)

                return;

        s->env = env;

        s->irq = irq;

        s->chr = chr;

        /* transmitter begins ready and idle.  */

        s->rs_stat_din |= (1 << STAT_TR_RDY);

        s->rs_stat_din |= (1 << STAT_TR_IDLE);

        qemu_chr_add_handlers(chr, serial_can_receive, serial_receive,

                              serial_event, s);

        ser_regs = cpu_register_io_memory(0, ser_read, ser_write, s);

        cpu_register_physical_memory (base, 0x3c, ser_regs);

}