hw/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 "sysbus.h"
  25 #include "sysemu.h"
  26 #include "qemu-timer.h"
  27
  28 #define D(x)
  29
  30 #define RW_TMR0_DIV   0x00
  31 #define R_TMR0_DATA   0x04
  32 #define RW_TMR0_CTRL  0x08
  33 #define RW_TMR1_DIV   0x10
  34 #define R_TMR1_DATA   0x14
  35 #define RW_TMR1_CTRL  0x18
  36 #define R_TIME        0x38
  37 #define RW_WD_CTRL    0x40
  38 #define R_WD_STAT     0x44
  39 #define RW_INTR_MASK  0x48
  40 #define RW_ACK_INTR   0x4c
  41 #define R_INTR        0x50
  42 #define R_MASKED_INTR 0x54
  43
  44 struct etrax_timer {
  45     SysBusDevice busdev;
  46     qemu_irq irq;
  47     qemu_irq nmi;
  48
  49     QEMUBH *bh_t0;
  50     QEMUBH *bh_t1;
  51     QEMUBH *bh_wd;
  52     ptimer_state *ptimer_t0;
  53     ptimer_state *ptimer_t1;
  54     ptimer_state *ptimer_wd;
  55
  56     int wd_hits;
  57
  58     /* Control registers.  */
  59     uint32_t rw_tmr0_div;
  60     uint32_t r_tmr0_data;
  61     uint32_t rw_tmr0_ctrl;
  62
  63     uint32_t rw_tmr1_div;
  64     uint32_t r_tmr1_data;
  65     uint32_t rw_tmr1_ctrl;
  66
  67     uint32_t rw_wd_ctrl;
  68
  69     uint32_t rw_intr_mask;
  70     uint32_t rw_ack_intr;
  71     uint32_t r_intr;
  72     uint32_t r_masked_intr;
  73 };
  74
  75 static uint32_t timer_readl (void *opaque, target_phys_addr_t addr)
  76 {
  77     struct etrax_timer *t = opaque;
  78     uint32_t r = 0;
  79
  80     switch (addr) {
  81     case R_TMR0_DATA:
  82         r = ptimer_get_count(t->ptimer_t0);
  83         break;
  84     case R_TMR1_DATA:
  85         r = ptimer_get_count(t->ptimer_t1);
  86         break;
  87     case R_TIME:
  88         r = qemu_get_clock(vm_clock) / 10;
  89         break;
  90     case RW_INTR_MASK:
  91         r = t->rw_intr_mask;
  92         break;
  93     case R_MASKED_INTR:
  94         r = t->r_intr & t->rw_intr_mask;
  95         break;
  96     default:
  97         D(printf ("%s %x\n", __func__, addr));
  98         break;
  99     }
 100     return r;
 101 }
 102
 103 #define TIMER_SLOWDOWN 1
 104 static void update_ctrl(struct etrax_timer *t, int tnum)
 105 {
 106     unsigned int op;
 107     unsigned int freq;
 108     unsigned int freq_hz;
 109     unsigned int div;
 110     uint32_t ctrl;
 111
 112     ptimer_state *timer;
 113
 114     if (tnum == 0) {
 115         ctrl = t->rw_tmr0_ctrl;
 116         div = t->rw_tmr0_div;
 117         timer = t->ptimer_t0;
 118     } else {
 119         ctrl = t->rw_tmr1_ctrl;
 120         div = t->rw_tmr1_div;
 121         timer = t->ptimer_t1;
 122     }
 123
 124
 125     op = ctrl & 3;
 126     freq = ctrl >> 2;
 127     freq_hz = 32000000;
 128
 129     switch (freq)
 130     {
 131     case 0:
 132     case 1:
 133         D(printf ("extern or disabled timer clock?\n"));
 134         break;
 135     case 4: freq_hz =  29493000; break;
 136     case 5: freq_hz =  32000000; break;
 137     case 6: freq_hz =  32768000; break;
 138     case 7: freq_hz = 100000000; break;
 139     default:
 140         abort();
 141         break;
 142     }
 143
 144     D(printf ("freq_hz=%d div=%d\n", freq_hz, div));
 145     div = div * TIMER_SLOWDOWN;
 146     div /= 1000;
 147     freq_hz /= 1000;
 148     ptimer_set_freq(timer, freq_hz);
 149     ptimer_set_limit(timer, div, 0);
 150
 151     switch (op)
 152     {
 153         case 0:
 154             /* Load.  */
 155             ptimer_set_limit(timer, div, 1);
 156             break;
 157         case 1:
 158             /* Hold.  */
 159             ptimer_stop(timer);
 160             break;
 161         case 2:
 162             /* Run.  */
 163             ptimer_run(timer, 0);
 164             break;
 165         default:
 166             abort();
 167             break;
 168     }
 169 }
 170
 171 static void timer_update_irq(struct etrax_timer *t)
 172 {
 173     t->r_intr &= ~(t->rw_ack_intr);
 174     t->r_masked_intr = t->r_intr & t->rw_intr_mask;
 175
 176     D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));
 177     qemu_set_irq(t->irq, !!t->r_masked_intr);
 178 }
 179
 180 static void timer0_hit(void *opaque)
 181 {
 182     struct etrax_timer *t = opaque;
 183     t->r_intr |= 1;
 184     timer_update_irq(t);
 185 }
 186
 187 static void timer1_hit(void *opaque)
 188 {
 189     struct etrax_timer *t = opaque;
 190     t->r_intr |= 2;
 191     timer_update_irq(t);
 192 }
 193
 194 static void watchdog_hit(void *opaque)
 195 {
 196     struct etrax_timer *t = opaque;
 197     if (t->wd_hits == 0) {
 198         /* real hw gives a single tick before reseting but we are
 199            a bit friendlier to compensate for our slower execution.  */
 200         ptimer_set_count(t->ptimer_wd, 10);
 201         ptimer_run(t->ptimer_wd, 1);
 202         qemu_irq_raise(t->nmi);
 203     }
 204     else
 205         qemu_system_reset_request();
 206
 207     t->wd_hits++;
 208 }
 209
 210 static inline void timer_watchdog_update(struct etrax_timer *t, uint32_t value)
 211 {
 212     unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);
 213     unsigned int wd_key = t->rw_wd_ctrl >> 9;
 214     unsigned int wd_cnt = t->rw_wd_ctrl & 511;
 215     unsigned int new_key = value >> 9 & ((1 << 7) - 1);
 216     unsigned int new_cmd = (value >> 8) & 1;
 217
 218     /* If the watchdog is enabled, they written key must match the
 219        complement of the previous.  */
 220     wd_key = ~wd_key & ((1 << 7) - 1);
 221
 222     if (wd_en && wd_key != new_key)
 223         return;
 224
 225     D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n",
 226          wd_en, new_key, wd_key, new_cmd, wd_cnt));
 227
 228     if (t->wd_hits)
 229         qemu_irq_lower(t->nmi);
 230
 231     t->wd_hits = 0;
 232
 233     ptimer_set_freq(t->ptimer_wd, 760);
 234     if (wd_cnt == 0)
 235         wd_cnt = 256;
 236     ptimer_set_count(t->ptimer_wd, wd_cnt);
 237     if (new_cmd)
 238         ptimer_run(t->ptimer_wd, 1);
 239     else
 240         ptimer_stop(t->ptimer_wd);
 241
 242     t->rw_wd_ctrl = value;
 243 }
 244
 245 static void
 246 timer_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
 247 {
 248     struct etrax_timer *t = opaque;
 249
 250     switch (addr)
 251     {
 252         case RW_TMR0_DIV:
 253             t->rw_tmr0_div = value;
 254             break;
 255         case RW_TMR0_CTRL:
 256             D(printf ("RW_TMR0_CTRL=%x\n", value));
 257             t->rw_tmr0_ctrl = value;
 258             update_ctrl(t, 0);
 259             break;
 260         case RW_TMR1_DIV:
 261             t->rw_tmr1_div = value;
 262             break;
 263         case RW_TMR1_CTRL:
 264             D(printf ("RW_TMR1_CTRL=%x\n", value));
 265             t->rw_tmr1_ctrl = value;
 266             update_ctrl(t, 1);
 267             break;
 268         case RW_INTR_MASK:
 269             D(printf ("RW_INTR_MASK=%x\n", value));
 270             t->rw_intr_mask = value;
 271             timer_update_irq(t);
 272             break;
 273         case RW_WD_CTRL:
 274             timer_watchdog_update(t, value);
 275             break;
 276         case RW_ACK_INTR:
 277             t->rw_ack_intr = value;
 278             timer_update_irq(t);
 279             t->rw_ack_intr = 0;
 280             break;
 281         default:
 282             printf ("%s " TARGET_FMT_plx " %x\n",
 283                 __func__, addr, value);
 284             break;
 285     }
 286 }
 287
 288 static CPUReadMemoryFunc * const timer_read[] = {
 289     NULL, NULL,
 290     &timer_readl,
 291 };
 292
 293 static CPUWriteMemoryFunc * const timer_write[] = {
 294     NULL, NULL,
 295     &timer_writel,
 296 };
 297
 298 static void etraxfs_timer_reset(void *opaque)
 299 {
 300     struct etrax_timer *t = opaque;
 301
 302     ptimer_stop(t->ptimer_t0);
 303     ptimer_stop(t->ptimer_t1);
 304     ptimer_stop(t->ptimer_wd);
 305     t->rw_wd_ctrl = 0;
 306     t->r_intr = 0;
 307     t->rw_intr_mask = 0;
 308     qemu_irq_lower(t->irq);
 309 }
 310
 311 static int etraxfs_timer_init(SysBusDevice *dev)
 312 {
 313     struct etrax_timer *t = FROM_SYSBUS(typeof (*t), dev);
 314     int timer_regs;
 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     timer_regs = cpu_register_io_memory(timer_read, timer_write, t,
 327                                         DEVICE_NATIVE_ENDIAN);
 328     sysbus_init_mmio(dev, 0x5c, timer_regs);
 329
 330     qemu_register_reset(etraxfs_timer_reset, t);
 331     return 0;
 332 }
 333
 334 static void etraxfs_timer_register(void)
 335 {
 336     sysbus_register_dev("etraxfs,timer", sizeof (struct etrax_timer),
 337                         etraxfs_timer_init);
 338 }
 339
 340 device_init(etraxfs_timer_register)