hw/timer/etraxfs_timer.c

   1 /*
   2  * QEMU ETRAX Timers
   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 #include "hw/sysbus.h"
  25 #include "sysemu/sysemu.h"
  26 #include "qemu/timer.h"
  27 #include "hw/ptimer.h"
  28
  29 #define D(x)
  30
  31 #define RW_TMR0_DIV   0x00
  32 #define R_TMR0_DATA   0x04
  33 #define RW_TMR0_CTRL  0x08
  34 #define RW_TMR1_DIV   0x10
  35 #define R_TMR1_DATA   0x14
  36 #define RW_TMR1_CTRL  0x18
  37 #define R_TIME        0x38
  38 #define RW_WD_CTRL    0x40
  39 #define R_WD_STAT     0x44
  40 #define RW_INTR_MASK  0x48
  41 #define RW_ACK_INTR   0x4c
  42 #define R_INTR        0x50
  43 #define R_MASKED_INTR 0x54
  44
  45 struct etrax_timer {
  46     SysBusDevice busdev;
  47     MemoryRegion mmio;
  48     qemu_irq irq;
  49     qemu_irq nmi;
  50
  51     QEMUBH *bh_t0;
  52     QEMUBH *bh_t1;
  53     QEMUBH *bh_wd;
  54     ptimer_state *ptimer_t0;
  55     ptimer_state *ptimer_t1;
  56     ptimer_state *ptimer_wd;
  57
  58     int wd_hits;
  59
  60     /* Control registers.  */
  61     uint32_t rw_tmr0_div;
  62     uint32_t r_tmr0_data;
  63     uint32_t rw_tmr0_ctrl;
  64
  65     uint32_t rw_tmr1_div;
  66     uint32_t r_tmr1_data;
  67     uint32_t rw_tmr1_ctrl;
  68
  69     uint32_t rw_wd_ctrl;
  70
  71     uint32_t rw_intr_mask;
  72     uint32_t rw_ack_intr;
  73     uint32_t r_intr;
  74     uint32_t r_masked_intr;
  75 };
  76
  77 static uint64_t
  78 timer_read(void *opaque, hwaddr addr, unsigned int size)
  79 {
  80     struct etrax_timer *t = opaque;
  81     uint32_t r = 0;
  82
  83     switch (addr) {
  84     case R_TMR0_DATA:
  85         r = ptimer_get_count(t->ptimer_t0);
  86         break;
  87     case R_TMR1_DATA:
  88         r = ptimer_get_count(t->ptimer_t1);
  89         break;
  90     case R_TIME:
  91         r = qemu_get_clock_ns(vm_clock) / 10;
  92         break;
  93     case RW_INTR_MASK:
  94         r = t->rw_intr_mask;
  95         break;
  96     case R_MASKED_INTR:
  97         r = t->r_intr & t->rw_intr_mask;
  98         break;
  99     default:
 100         D(printf ("%s %x\n", __func__, addr));
 101         break;
 102     }
 103     return r;
 104 }
 105
 106 static void update_ctrl(struct etrax_timer *t, int tnum)
 107 {
 108     unsigned int op;
 109     unsigned int freq;
 110     unsigned int freq_hz;
 111     unsigned int div;
 112     uint32_t ctrl;
 113
 114     ptimer_state *timer;
 115
 116     if (tnum == 0) {
 117         ctrl = t->rw_tmr0_ctrl;
 118         div = t->rw_tmr0_div;
 119         timer = t->ptimer_t0;
 120     } else {
 121         ctrl = t->rw_tmr1_ctrl;
 122         div = t->rw_tmr1_div;
 123         timer = t->ptimer_t1;
 124     }
 125
 126
 127     op = ctrl & 3;
 128     freq = ctrl >> 2;
 129     freq_hz = 32000000;
 130
 131     switch (freq)
 132     {
 133     case 0:
 134     case 1:
 135         D(printf ("extern or disabled timer clock?\n"));
 136         break;
 137     case 4: freq_hz =  29493000; break;
 138     case 5: freq_hz =  32000000; break;
 139     case 6: freq_hz =  32768000; break;
 140     case 7: freq_hz = 100000000; break;
 141     default:
 142         abort();
 143         break;
 144     }
 145
 146     D(printf ("freq_hz=%d div=%d\n", freq_hz, div));
 147     ptimer_set_freq(timer, freq_hz);
 148     ptimer_set_limit(timer, div, 0);
 149
 150     switch (op)
 151     {
 152         case 0:
 153             /* Load.  */
 154             ptimer_set_limit(timer, div, 1);
 155             break;
 156         case 1:
 157             /* Hold.  */
 158             ptimer_stop(timer);
 159             break;
 160         case 2:
 161             /* Run.  */
 162             ptimer_run(timer, 0);
 163             break;
 164         default:
 165             abort();
 166             break;
 167     }
 168 }
 169
 170 static void timer_update_irq(struct etrax_timer *t)
 171 {
 172     t->r_intr &= ~(t->rw_ack_intr);
 173     t->r_masked_intr = t->r_intr & t->rw_intr_mask;
 174
 175     D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));
 176     qemu_set_irq(t->irq, !!t->r_masked_intr);
 177 }
 178
 179 static void timer0_hit(void *opaque)
 180 {
 181     struct etrax_timer *t = opaque;
 182     t->r_intr |= 1;
 183     timer_update_irq(t);
 184 }
 185
 186 static void timer1_hit(void *opaque)
 187 {
 188     struct etrax_timer *t = opaque;
 189     t->r_intr |= 2;
 190     timer_update_irq(t);
 191 }
 192
 193 static void watchdog_hit(void *opaque)
 194 {
 195     struct etrax_timer *t = opaque;
 196     if (t->wd_hits == 0) {
 197         /* real hw gives a single tick before reseting but we are
 198            a bit friendlier to compensate for our slower execution.  */
 199         ptimer_set_count(t->ptimer_wd, 10);
 200         ptimer_run(t->ptimer_wd, 1);
 201         qemu_irq_raise(t->nmi);
 202     }
 203     else
 204         qemu_system_reset_request();
 205
 206     t->wd_hits++;
 207 }
 208
 209 static inline void timer_watchdog_update(struct etrax_timer *t, uint32_t value)
 210 {
 211     unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);
 212     unsigned int wd_key = t->rw_wd_ctrl >> 9;
 213     unsigned int wd_cnt = t->rw_wd_ctrl & 511;
 214     unsigned int new_key = value >> 9 & ((1 << 7) - 1);
 215     unsigned int new_cmd = (value >> 8) & 1;
 216
 217     /* If the watchdog is enabled, they written key must match the
 218        complement of the previous.  */
 219     wd_key = ~wd_key & ((1 << 7) - 1);
 220
 221     if (wd_en && wd_key != new_key)
 222         return;
 223
 224     D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n",
 225          wd_en, new_key, wd_key, new_cmd, wd_cnt));
 226
 227     if (t->wd_hits)
 228         qemu_irq_lower(t->nmi);
 229
 230     t->wd_hits = 0;
 231
 232     ptimer_set_freq(t->ptimer_wd, 760);
 233     if (wd_cnt == 0)
 234         wd_cnt = 256;
 235     ptimer_set_count(t->ptimer_wd, wd_cnt);
 236     if (new_cmd)
 237         ptimer_run(t->ptimer_wd, 1);
 238     else
 239         ptimer_stop(t->ptimer_wd);
 240
 241     t->rw_wd_ctrl = value;
 242 }
 243
 244 static void
 245 timer_write(void *opaque, hwaddr addr,
 246             uint64_t val64, unsigned int size)
 247 {
 248     struct etrax_timer *t = opaque;
 249     uint32_t value = val64;
 250
 251     switch (addr)
 252     {
 253         case RW_TMR0_DIV:
 254             t->rw_tmr0_div = value;
 255             break;
 256         case RW_TMR0_CTRL:
 257             D(printf ("RW_TMR0_CTRL=%x\n", value));
 258             t->rw_tmr0_ctrl = value;
 259             update_ctrl(t, 0);
 260             break;
 261         case RW_TMR1_DIV:
 262             t->rw_tmr1_div = value;
 263             break;
 264         case RW_TMR1_CTRL:
 265             D(printf ("RW_TMR1_CTRL=%x\n", value));
 266             t->rw_tmr1_ctrl = value;
 267             update_ctrl(t, 1);
 268             break;
 269         case RW_INTR_MASK:
 270             D(printf ("RW_INTR_MASK=%x\n", value));
 271             t->rw_intr_mask = value;
 272             timer_update_irq(t);
 273             break;
 274         case RW_WD_CTRL:
 275             timer_watchdog_update(t, value);
 276             break;
 277         case RW_ACK_INTR:
 278             t->rw_ack_intr = value;
 279             timer_update_irq(t);
 280             t->rw_ack_intr = 0;
 281             break;
 282         default:
 283             printf ("%s " TARGET_FMT_plx " %x\n",
 284                 __func__, addr, value);
 285             break;
 286     }
 287 }
 288
 289 static const MemoryRegionOps timer_ops = {
 290     .read = timer_read,
 291     .write = timer_write,
 292     .endianness = DEVICE_LITTLE_ENDIAN,
 293     .valid = {
 294         .min_access_size = 4,
 295         .max_access_size = 4
 296     }
 297 };
 298
 299 static void etraxfs_timer_reset(void *opaque)
 300 {
 301     struct etrax_timer *t = opaque;
 302
 303     ptimer_stop(t->ptimer_t0);
 304     ptimer_stop(t->ptimer_t1);
 305     ptimer_stop(t->ptimer_wd);
 306     t->rw_wd_ctrl = 0;
 307     t->r_intr = 0;
 308     t->rw_intr_mask = 0;
 309     qemu_irq_lower(t->irq);
 310 }
 311
 312 static int etraxfs_timer_init(SysBusDevice *dev)
 313 {
 314     struct etrax_timer *t = FROM_SYSBUS(typeof (*t), dev);
 315
 316     t->bh_t0 = qemu_bh_new(timer0_hit, t);
 317     t->bh_t1 = qemu_bh_new(timer1_hit, t);
 318     t->bh_wd = qemu_bh_new(watchdog_hit, t);
 319     t->ptimer_t0 = ptimer_init(t->bh_t0);
 320     t->ptimer_t1 = ptimer_init(t->bh_t1);
 321     t->ptimer_wd = ptimer_init(t->bh_wd);
 322
 323     sysbus_init_irq(dev, &t->irq);
 324     sysbus_init_irq(dev, &t->nmi);
 325
 326     memory_region_init_io(&t->mmio, &timer_ops, t, "etraxfs-timer", 0x5c);
 327     sysbus_init_mmio(dev, &t->mmio);
 328     qemu_register_reset(etraxfs_timer_reset, t);
 329     return 0;
 330 }
 331
 332 static void etraxfs_timer_class_init(ObjectClass *klass, void *data)
 333 {
 334     SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
 335
 336     sdc->init = etraxfs_timer_init;
 337 }
 338
 339 static const TypeInfo etraxfs_timer_info = {
 340     .name          = "etraxfs,timer",
 341     .parent        = TYPE_SYS_BUS_DEVICE,
 342     .instance_size = sizeof (struct etrax_timer),
 343     .class_init    = etraxfs_timer_class_init,
 344 };
 345
 346 static void etraxfs_timer_register_types(void)
 347 {
 348     type_register_static(&etraxfs_timer_info);
 349 }
 350
 351 type_init(etraxfs_timer_register_types)