hw/etraxfs_ser.c

   1 /*
   2  * QEMU ETRAX System Emulator
   3  *
   4  * Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include <stdio.h>
  26 #include <ctype.h>
  27 #include "hw.h"
  28 #include "qemu-char.h"
  29
  30 #define D(x)
  31
  32 #define RW_TR_CTRL     0x00
  33 #define RW_TR_DMA_EN   0x04
  34 #define RW_REC_CTRL    0x08
  35 #define RW_DOUT        0x1c
  36 #define RS_STAT_DIN    0x20
  37 #define R_STAT_DIN     0x24
  38 #define RW_INTR_MASK   0x2c
  39 #define RW_ACK_INTR    0x30
  40 #define R_INTR         0x34
  41 #define R_MASKED_INTR  0x38
  42
  43 #define STAT_DAV     16
  44 #define STAT_TR_IDLE 22
  45 #define STAT_TR_RDY  24
  46
  47 struct etrax_serial_t
  48 {
  49         CPUState *env;
  50         CharDriverState *chr;
  51         qemu_irq *irq;
  52
  53         int pending_tx;
  54
  55         /* Control registers.  */
  56         uint32_t rw_tr_ctrl;
  57         uint32_t rw_tr_dma_en;
  58         uint32_t rw_rec_ctrl;
  59         uint32_t rs_stat_din;
  60         uint32_t r_stat_din;
  61         uint32_t rw_intr_mask;
  62         uint32_t rw_ack_intr;
  63         uint32_t r_intr;
  64         uint32_t r_masked_intr;
  65 };
  66
  67 static void ser_update_irq(struct etrax_serial_t *s)
  68 {
  69         uint32_t o_irq = s->r_masked_intr;
  70
  71         s->r_intr &= ~(s->rw_ack_intr);
  72         s->r_masked_intr = s->r_intr & s->rw_intr_mask;
  73
  74         if (o_irq != s->r_masked_intr) {
  75                 D(printf("irq_mask=%x r_intr=%x rmi=%x airq=%x \n",
  76                          s->rw_intr_mask, s->r_intr,
  77                          s->r_masked_intr, s->rw_ack_intr));
  78                 if (s->r_masked_intr)
  79                         qemu_irq_raise(s->irq[0]);
  80                 else
  81                         qemu_irq_lower(s->irq[0]);
  82         }
  83         s->rw_ack_intr = 0;
  84 }
  85
  86
  87 static uint32_t ser_readb (void *opaque, target_phys_addr_t addr)
  88 {
  89         D(CPUState *env = opaque);
  90         D(printf ("%s %x\n", __func__, addr));
  91         return 0;
  92 }
  93
  94 static uint32_t ser_readl (void *opaque, target_phys_addr_t addr)
  95 {
  96         struct etrax_serial_t *s = opaque;
  97         D(CPUState *env = s->env);
  98         uint32_t r = 0;
  99
 100         switch (addr)
 101         {
 102                 case RW_TR_CTRL:
 103                         r = s->rw_tr_ctrl;
 104                         break;
 105                 case RW_TR_DMA_EN:
 106                         r = s->rw_tr_dma_en;
 107                         break;
 108                 case RS_STAT_DIN:
 109                         r = s->rs_stat_din;
 110                         /* clear dav.  */
 111                         s->rs_stat_din &= ~(1 << STAT_DAV);
 112                         break;
 113                 case R_STAT_DIN:
 114                         r = s->rs_stat_din;
 115                         break;
 116                 case RW_ACK_INTR:
 117                         D(printf("load rw_ack_intr=%x\n", s->rw_ack_intr));
 118                         r = s->rw_ack_intr;
 119                         break;
 120                 case RW_INTR_MASK:
 121                         r = s->rw_intr_mask;
 122                         break;
 123                 case R_INTR:
 124                         D(printf("load r_intr=%x\n", s->r_intr));
 125                         r = s->r_intr;
 126                         break;
 127                 case R_MASKED_INTR:
 128                         D(printf("load r_maked_intr=%x\n", s->r_masked_intr));
 129                         r = s->r_masked_intr;
 130                         break;
 131
 132                 default:
 133                         D(printf ("%s %x\n", __func__, addr));
 134                         break;
 135         }
 136         return r;
 137 }
 138
 139 static void
 140 ser_writeb (void *opaque, target_phys_addr_t addr, uint32_t value)
 141 {
 142         D(struct etrax_serial_t *s = opaque);
 143         D(CPUState *env = s->env);
 144         D(printf ("%s %x %x\n", __func__, addr, value));
 145 }
 146 static void
 147 ser_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
 148 {
 149         struct etrax_serial_t *s = opaque;
 150         unsigned char ch = value;
 151         D(CPUState *env = s->env);
 152
 153         switch (addr)
 154         {
 155                 case RW_TR_CTRL:
 156                         D(printf("rw_tr_ctrl=%x\n", value));
 157                         s->rw_tr_ctrl = value;
 158                         break;
 159                 case RW_TR_DMA_EN:
 160                         D(printf("rw_tr_dma_en=%x\n", value));
 161                         s->rw_tr_dma_en = value;
 162                         break;
 163                 case RW_DOUT:
 164                         qemu_chr_write(s->chr, &ch, 1);
 165                         s->r_intr |= 1;
 166                         s->pending_tx = 1;
 167                         break;
 168                 case RW_ACK_INTR:
 169                         D(printf("rw_ack_intr=%x\n", value));
 170                         s->rw_ack_intr = value;
 171                         if (s->pending_tx && (s->rw_ack_intr & 1)) {
 172                                 s->r_intr |= 1;
 173                                 s->pending_tx = 0;
 174                                 s->rw_ack_intr &= ~1;
 175                         }
 176                         break;
 177                 case RW_INTR_MASK:
 178                         D(printf("r_intr_mask=%x\n", value));
 179                         s->rw_intr_mask = value;
 180                         break;
 181                 default:
 182                         D(printf ("%s %x %x\n",  __func__, addr, value));
 183                         break;
 184         }
 185         ser_update_irq(s);
 186 }
 187
 188 static CPUReadMemoryFunc *ser_read[] = {
 189         &ser_readb,
 190         &ser_readb,
 191         &ser_readl,
 192 };
 193
 194 static CPUWriteMemoryFunc *ser_write[] = {
 195         &ser_writeb,
 196         &ser_writeb,
 197         &ser_writel,
 198 };
 199
 200 static void serial_receive(void *opaque, const uint8_t *buf, int size)
 201 {
 202         struct etrax_serial_t *s = opaque;
 203
 204         s->r_intr |= 8;
 205         s->rs_stat_din &= ~0xff;
 206         s->rs_stat_din |= (buf[0] & 0xff);
 207         s->rs_stat_din |= (1 << STAT_DAV); /* dav.  */
 208         ser_update_irq(s);
 209 }
 210
 211 static int serial_can_receive(void *opaque)
 212 {
 213         struct etrax_serial_t *s = opaque;
 214         int r;
 215
 216         /* Is the receiver enabled?  */
 217         r = s->rw_rec_ctrl & 1;
 218
 219         /* Pending rx data?  */
 220         r |= !(s->r_intr & 8);
 221         return r;
 222 }
 223
 224 static void serial_event(void *opaque, int event)
 225 {
 226
 227 }
 228
 229 void etraxfs_ser_init(CPUState *env, qemu_irq *irq, CharDriverState *chr,
 230                       target_phys_addr_t base)
 231 {
 232         struct etrax_serial_t *s;
 233         int ser_regs;
 234
 235         s = qemu_mallocz(sizeof *s);
 236         if (!s)
 237                 return;
 238
 239         s->env = env;
 240         s->irq = irq;
 241         s->chr = chr;
 242
 243         /* transmitter begins ready and idle.  */
 244         s->rs_stat_din |= (1 << STAT_TR_RDY);
 245         s->rs_stat_din |= (1 << STAT_TR_IDLE);
 246
 247         qemu_chr_add_handlers(chr, serial_can_receive, serial_receive,
 248                               serial_event, s);
 249
 250         ser_regs = cpu_register_io_memory(0, ser_read, ser_write, s);
 251         cpu_register_physical_memory (base, 0x3c, ser_regs);
 252 }