hw/xilinx_timer.c

   1 /*
   2  * QEMU model of the Xilinx timer block.
   3  *
   4  * Copyright (c) 2009 Edgar E. Iglesias.
   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 "sysbus.h"
  26 #include "ptimer.h"
  27 #include "qemu-log.h"
  28
  29 #define D(x)
  30
  31 #define R_TCSR     0
  32 #define R_TLR      1
  33 #define R_TCR      2
  34 #define R_MAX      4
  35
  36 #define TCSR_MDT        (1<<0)
  37 #define TCSR_UDT        (1<<1)
  38 #define TCSR_GENT       (1<<2)
  39 #define TCSR_CAPT       (1<<3)
  40 #define TCSR_ARHT       (1<<4)
  41 #define TCSR_LOAD       (1<<5)
  42 #define TCSR_ENIT       (1<<6)
  43 #define TCSR_ENT        (1<<7)
  44 #define TCSR_TINT       (1<<8)
  45 #define TCSR_PWMA       (1<<9)
  46 #define TCSR_ENALL      (1<<10)
  47
  48 struct xlx_timer
  49 {
  50     QEMUBH *bh;
  51     ptimer_state *ptimer;
  52     void *parent;
  53     int nr; /* for debug.  */
  54
  55     unsigned long timer_div;
  56
  57     uint32_t regs[R_MAX];
  58 };
  59
  60 struct timerblock
  61 {
  62     SysBusDevice busdev;
  63     MemoryRegion mmio;
  64     qemu_irq irq;
  65     uint8_t one_timer_only;
  66     uint32_t freq_hz;
  67     struct xlx_timer *timers;
  68 };
  69
  70 static inline unsigned int num_timers(struct timerblock *t)
  71 {
  72     return 2 - t->one_timer_only;
  73 }
  74
  75 static inline unsigned int timer_from_addr(hwaddr addr)
  76 {
  77     /* Timers get a 4x32bit control reg area each.  */
  78     return addr >> 2;
  79 }
  80
  81 static void timer_update_irq(struct timerblock *t)
  82 {
  83     unsigned int i, irq = 0;
  84     uint32_t csr;
  85
  86     for (i = 0; i < num_timers(t); i++) {
  87         csr = t->timers[i].regs[R_TCSR];
  88         irq |= (csr & TCSR_TINT) && (csr & TCSR_ENIT);
  89     }
  90
  91     /* All timers within the same slave share a single IRQ line.  */
  92     qemu_set_irq(t->irq, !!irq);
  93 }
  94
  95 static uint64_t
  96 timer_read(void *opaque, hwaddr addr, unsigned int size)
  97 {
  98     struct timerblock *t = opaque;
  99     struct xlx_timer *xt;
 100     uint32_t r = 0;
 101     unsigned int timer;
 102
 103     addr >>= 2;
 104     timer = timer_from_addr(addr);
 105     xt = &t->timers[timer];
 106     /* Further decoding to address a specific timers reg.  */
 107     addr &= 0x3;
 108     switch (addr)
 109     {
 110         case R_TCR:
 111                 r = ptimer_get_count(xt->ptimer);
 112                 if (!(xt->regs[R_TCSR] & TCSR_UDT))
 113                     r = ~r;
 114                 D(qemu_log("xlx_timer t=%d read counter=%x udt=%d\n",
 115                          timer, r, xt->regs[R_TCSR] & TCSR_UDT));
 116             break;
 117         default:
 118             if (addr < ARRAY_SIZE(xt->regs))
 119                 r = xt->regs[addr];
 120             break;
 121
 122     }
 123     D(fprintf(stderr, "%s timer=%d %x=%x\n", __func__, timer, addr * 4, r));
 124     return r;
 125 }
 126
 127 static void timer_enable(struct xlx_timer *xt)
 128 {
 129     uint64_t count;
 130
 131     D(fprintf(stderr, "%s timer=%d down=%d\n", __func__,
 132               xt->nr, xt->regs[R_TCSR] & TCSR_UDT));
 133
 134     ptimer_stop(xt->ptimer);
 135
 136     if (xt->regs[R_TCSR] & TCSR_UDT)
 137         count = xt->regs[R_TLR];
 138     else
 139         count = ~0 - xt->regs[R_TLR];
 140     ptimer_set_limit(xt->ptimer, count, 1);
 141     ptimer_run(xt->ptimer, 1);
 142 }
 143
 144 static void
 145 timer_write(void *opaque, hwaddr addr,
 146             uint64_t val64, unsigned int size)
 147 {
 148     struct timerblock *t = opaque;
 149     struct xlx_timer *xt;
 150     unsigned int timer;
 151     uint32_t value = val64;
 152
 153     addr >>= 2;
 154     timer = timer_from_addr(addr);
 155     xt = &t->timers[timer];
 156     D(fprintf(stderr, "%s addr=%x val=%x (timer=%d off=%d)\n",
 157              __func__, addr * 4, value, timer, addr & 3));
 158     /* Further decoding to address a specific timers reg.  */
 159     addr &= 3;
 160     switch (addr)
 161     {
 162         case R_TCSR:
 163             if (value & TCSR_TINT)
 164                 value &= ~TCSR_TINT;
 165
 166             xt->regs[addr] = value;
 167             if (value & TCSR_ENT)
 168                 timer_enable(xt);
 169             break;
 170
 171         default:
 172             if (addr < ARRAY_SIZE(xt->regs))
 173                 xt->regs[addr] = value;
 174             break;
 175     }
 176     timer_update_irq(t);
 177 }
 178
 179 static const MemoryRegionOps timer_ops = {
 180     .read = timer_read,
 181     .write = timer_write,
 182     .endianness = DEVICE_NATIVE_ENDIAN,
 183     .valid = {
 184         .min_access_size = 4,
 185         .max_access_size = 4
 186     }
 187 };
 188
 189 static void timer_hit(void *opaque)
 190 {
 191     struct xlx_timer *xt = opaque;
 192     struct timerblock *t = xt->parent;
 193     D(fprintf(stderr, "%s %d\n", __func__, xt->nr));
 194     xt->regs[R_TCSR] |= TCSR_TINT;
 195
 196     if (xt->regs[R_TCSR] & TCSR_ARHT)
 197         timer_enable(xt);
 198     timer_update_irq(t);
 199 }
 200
 201 static int xilinx_timer_init(SysBusDevice *dev)
 202 {
 203     struct timerblock *t = FROM_SYSBUS(typeof (*t), dev);
 204     unsigned int i;
 205
 206     /* All timers share a single irq line.  */
 207     sysbus_init_irq(dev, &t->irq);
 208
 209     /* Init all the ptimers.  */
 210     t->timers = g_malloc0(sizeof t->timers[0] * num_timers(t));
 211     for (i = 0; i < num_timers(t); i++) {
 212         struct xlx_timer *xt = &t->timers[i];
 213
 214         xt->parent = t;
 215         xt->nr = i;
 216         xt->bh = qemu_bh_new(timer_hit, xt);
 217         xt->ptimer = ptimer_init(xt->bh);
 218         ptimer_set_freq(xt->ptimer, t->freq_hz);
 219     }
 220
 221     memory_region_init_io(&t->mmio, &timer_ops, t, "xlnx.xps-timer",
 222                           R_MAX * 4 * num_timers(t));
 223     sysbus_init_mmio(dev, &t->mmio);
 224     return 0;
 225 }
 226
 227 static Property xilinx_timer_properties[] = {
 228     DEFINE_PROP_UINT32("clock-frequency", struct timerblock, freq_hz,
 229                                                                 62 * 1000000),
 230     DEFINE_PROP_UINT8("one-timer-only", struct timerblock, one_timer_only, 0),
 231     DEFINE_PROP_END_OF_LIST(),
 232 };
 233
 234 static void xilinx_timer_class_init(ObjectClass *klass, void *data)
 235 {
 236     DeviceClass *dc = DEVICE_CLASS(klass);
 237     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 238
 239     k->init = xilinx_timer_init;
 240     dc->props = xilinx_timer_properties;
 241 }
 242
 243 static TypeInfo xilinx_timer_info = {
 244     .name          = "xlnx.xps-timer",
 245     .parent        = TYPE_SYS_BUS_DEVICE,
 246     .instance_size = sizeof(struct timerblock),
 247     .class_init    = xilinx_timer_class_init,
 248 };
 249
 250 static void xilinx_timer_register_types(void)
 251 {
 252     type_register_static(&xilinx_timer_info);
 253 }
 254
 255 type_init(xilinx_timer_register_types)