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         target_phys_addr_t base;
  54
  55         int pending_tx;
  56
  57         /* Control registers.  */
  58         uint32_t rw_tr_ctrl;
  59         uint32_t rw_tr_dma_en;
  60         uint32_t rw_rec_ctrl;
  61         uint32_t rs_stat_din;
  62         uint32_t r_stat_din;
  63         uint32_t rw_intr_mask;
  64         uint32_t rw_ack_intr;
  65         uint32_t r_intr;
  66         uint32_t r_masked_intr;
  67 };
  68
  69 static void ser_update_irq(struct etrax_serial_t *s)
  70 {
  71         uint32_t o_irq = s->r_masked_intr;
  72
  73         s->r_intr &= ~(s->rw_ack_intr);
  74         s->r_masked_intr = s->r_intr & s->rw_intr_mask;
  75
  76         if (o_irq != s->r_masked_intr) {
  77                 D(printf("irq_mask=%x r_intr=%x rmi=%x airq=%x \n",
  78                          s->rw_intr_mask, s->r_intr,
  79                          s->r_masked_intr, s->rw_ack_intr));
  80                 if (s->r_masked_intr)
  81                         qemu_irq_raise(s->irq[0]);
  82                 else
  83                         qemu_irq_lower(s->irq[0]);
  84         }
  85         s->rw_ack_intr = 0;
  86 }
  87
  88
  89 static uint32_t ser_readb (void *opaque, target_phys_addr_t addr)
  90 {
  91         D(CPUState *env = opaque);
  92         D(printf ("%s %x\n", __func__, addr));
  93         return 0;
  94 }
  95
  96 static uint32_t ser_readl (void *opaque, target_phys_addr_t addr)
  97 {
  98         struct etrax_serial_t *s = opaque;
  99         D(CPUState *env = s->env);
 100         uint32_t r = 0;
 101
 102         switch (addr & 0xfff)
 103         {
 104                 case RW_TR_CTRL:
 105                         r = s->rw_tr_ctrl;
 106                         break;
 107                 case RW_TR_DMA_EN:
 108                         r = s->rw_tr_dma_en;
 109                         break;
 110                 case RS_STAT_DIN:
 111                         r = s->rs_stat_din;
 112                         /* clear dav.  */
 113                         s->rs_stat_din &= ~(1 << STAT_DAV);
 114                         break;
 115                 case R_STAT_DIN:
 116                         r = s->rs_stat_din;
 117                         break;
 118                 case RW_ACK_INTR:
 119                         D(printf("load rw_ack_intr=%x\n", s->rw_ack_intr));
 120                         r = s->rw_ack_intr;
 121                         break;
 122                 case RW_INTR_MASK:
 123                         r = s->rw_intr_mask;
 124                         break;
 125                 case R_INTR:
 126                         D(printf("load r_intr=%x\n", s->r_intr));
 127                         r = s->r_intr;
 128                         break;
 129                 case R_MASKED_INTR:
 130                         D(printf("load r_maked_intr=%x\n", s->r_masked_intr));
 131                         r = s->r_masked_intr;
 132                         break;
 133
 134                 default:
 135                         D(printf ("%s %x\n", __func__, addr));
 136                         break;
 137         }
 138         return r;
 139 }
 140
 141 static void
 142 ser_writeb (void *opaque, target_phys_addr_t addr, uint32_t value)
 143 {
 144         D(struct etrax_serial_t *s = opaque);
 145         D(CPUState *env = s->env);
 146         D(printf ("%s %x %x\n", __func__, addr, value));
 147 }
 148 static void
 149 ser_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
 150 {
 151         struct etrax_serial_t *s = opaque;
 152         unsigned char ch = value;
 153         D(CPUState *env = s->env);
 154
 155         switch (addr & 0xfff)
 156         {
 157                 case RW_TR_CTRL:
 158                         D(printf("rw_tr_ctrl=%x\n", value));
 159                         s->rw_tr_ctrl = value;
 160                         break;
 161                 case RW_TR_DMA_EN:
 162                         D(printf("rw_tr_dma_en=%x\n", value));
 163                         s->rw_tr_dma_en = value;
 164                         break;
 165                 case RW_DOUT:
 166                         qemu_chr_write(s->chr, &ch, 1);
 167                         s->r_intr |= 1;
 168                         s->pending_tx = 1;
 169                         break;
 170                 case RW_ACK_INTR:
 171                         D(printf("rw_ack_intr=%x\n", value));
 172                         s->rw_ack_intr = value;
 173                         if (s->pending_tx && (s->rw_ack_intr & 1)) {
 174                                 s->r_intr |= 1;
 175                                 s->pending_tx = 0;
 176                                 s->rw_ack_intr &= ~1;
 177                         }
 178                         break;
 179                 case RW_INTR_MASK:
 180                         D(printf("r_intr_mask=%x\n", value));
 181                         s->rw_intr_mask = value;
 182                         break;
 183                 default:
 184                         D(printf ("%s %x %x\n",  __func__, addr, value));
 185                         break;
 186         }
 187         ser_update_irq(s);
 188 }
 189
 190 static CPUReadMemoryFunc *ser_read[] = {
 191         &ser_readb,
 192         &ser_readb,
 193         &ser_readl,
 194 };
 195
 196 static CPUWriteMemoryFunc *ser_write[] = {
 197         &ser_writeb,
 198         &ser_writeb,
 199         &ser_writel,
 200 };
 201
 202 static void serial_receive(void *opaque, const uint8_t *buf, int size)
 203 {
 204         struct etrax_serial_t *s = opaque;
 205
 206         s->r_intr |= 8;
 207         s->rs_stat_din &= ~0xff;
 208         s->rs_stat_din |= (buf[0] & 0xff);
 209         s->rs_stat_din |= (1 << STAT_DAV); /* dav.  */
 210         ser_update_irq(s);
 211 }
 212
 213 static int serial_can_receive(void *opaque)
 214 {
 215         struct etrax_serial_t *s = opaque;
 216         int r;
 217
 218         /* Is the receiver enabled?  */
 219         r = s->rw_rec_ctrl & 1;
 220
 221         /* Pending rx data?  */
 222         r |= !(s->r_intr & 8);
 223         return r;
 224 }
 225
 226 static void serial_event(void *opaque, int event)
 227 {
 228
 229 }
 230
 231 void etraxfs_ser_init(CPUState *env, qemu_irq *irq, CharDriverState *chr,
 232                       target_phys_addr_t base)
 233 {
 234         struct etrax_serial_t *s;
 235         int ser_regs;
 236
 237         s = qemu_mallocz(sizeof *s);
 238         if (!s)
 239                 return;
 240
 241         s->env = env;
 242         s->irq = irq;
 243         s->base = base;
 244
 245         s->chr = chr;
 246
 247         /* transmitter begins ready and idle.  */
 248         s->rs_stat_din |= (1 << STAT_TR_RDY);
 249         s->rs_stat_din |= (1 << STAT_TR_IDLE);
 250
 251         qemu_chr_add_handlers(chr, serial_can_receive, serial_receive,
 252                               serial_event, s);
 253
 254         ser_regs = cpu_register_io_memory(0, ser_read, ser_write, s);
 255         cpu_register_physical_memory (base, 0x3c, ser_regs);
 256 }