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 "sysemu.h"
  27 #include "qemu-timer.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     qemu_irq irq;
  64     unsigned int nr_timers;
  65     struct xlx_timer *timers;
  66 };
  67
  68 static inline unsigned int timer_from_addr(target_phys_addr_t addr)
  69 {
  70     /* Timers get a 4x32bit control reg area each.  */
  71     return addr >> 2;
  72 }
  73
  74 static void timer_update_irq(struct timerblock *t)
  75 {
  76     unsigned int i, irq = 0;
  77     uint32_t csr;
  78
  79     for (i = 0; i < t->nr_timers; i++) {
  80         csr = t->timers[i].regs[R_TCSR];
  81         irq |= (csr & TCSR_TINT) && (csr & TCSR_ENIT);
  82     }
  83
  84     /* All timers within the same slave share a single IRQ line.  */
  85     qemu_set_irq(t->irq, !!irq);
  86 }
  87
  88 static uint32_t timer_readl (void *opaque, target_phys_addr_t addr)
  89 {
  90     struct timerblock *t = opaque;
  91     struct xlx_timer *xt;
  92     uint32_t r = 0;
  93     unsigned int timer;
  94
  95     addr >>= 2;
  96     timer = timer_from_addr(addr);
  97     xt = &t->timers[timer];
  98     /* Further decoding to address a specific timers reg.  */
  99     addr &= 0x3;
 100     switch (addr)
 101     {
 102         case R_TCR:
 103                 r = ptimer_get_count(xt->ptimer);
 104                 if (!(xt->regs[R_TCSR] & TCSR_UDT))
 105                     r = ~r;
 106                 D(qemu_log("xlx_timer t=%d read counter=%x udt=%d\n",
 107                          timer, r, xt->regs[R_TCSR] & TCSR_UDT));
 108             break;
 109         default:
 110             if (addr < ARRAY_SIZE(xt->regs))
 111                 r = xt->regs[addr];
 112             break;
 113
 114     }
 115     D(printf("%s timer=%d %x=%x\n", __func__, timer, addr * 4, r));
 116     return r;
 117 }
 118
 119 static void timer_enable(struct xlx_timer *xt)
 120 {
 121     uint64_t count;
 122
 123     D(printf("%s timer=%d down=%d\n", __func__,
 124               xt->nr, xt->regs[R_TCSR] & TCSR_UDT));
 125
 126     ptimer_stop(xt->ptimer);
 127
 128     if (xt->regs[R_TCSR] & TCSR_UDT)
 129         count = xt->regs[R_TLR];
 130     else
 131         count = ~0 - xt->regs[R_TLR];
 132     ptimer_set_count(xt->ptimer, count);
 133     ptimer_run(xt->ptimer, 1);
 134 }
 135
 136 static void
 137 timer_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
 138 {
 139     struct timerblock *t = opaque;
 140     struct xlx_timer *xt;
 141     unsigned int timer;
 142
 143     addr >>= 2;
 144     timer = timer_from_addr(addr);
 145     xt = &t->timers[timer];
 146     D(printf("%s addr=%x val=%x (timer=%d off=%d)\n",
 147              __func__, addr * 4, value, timer, addr & 3));
 148     /* Further decoding to address a specific timers reg.  */
 149     addr &= 3;
 150     switch (addr)
 151     {
 152         case R_TCSR:
 153             if (value & TCSR_TINT)
 154                 value &= ~TCSR_TINT;
 155
 156             xt->regs[addr] = value;
 157             if (value & TCSR_ENT)
 158                 timer_enable(xt);
 159             break;
 160
 161         default:
 162             if (addr < ARRAY_SIZE(xt->regs))
 163                 xt->regs[addr] = value;
 164             break;
 165     }
 166     timer_update_irq(t);
 167 }
 168
 169 static CPUReadMemoryFunc *timer_read[] = {
 170     NULL, NULL,
 171     &timer_readl,
 172 };
 173
 174 static CPUWriteMemoryFunc *timer_write[] = {
 175     NULL, NULL,
 176     &timer_writel,
 177 };
 178
 179 static void timer_hit(void *opaque)
 180 {
 181     struct xlx_timer *xt = opaque;
 182     struct timerblock *t = xt->parent;
 183     D(printf("%s %d\n", __func__, timer));
 184     xt->regs[R_TCSR] |= TCSR_TINT;
 185
 186     if (xt->regs[R_TCSR] & TCSR_ARHT)
 187         timer_enable(xt);
 188     timer_update_irq(t);
 189 }
 190
 191 static void xilinx_timer_init(SysBusDevice *dev)
 192 {
 193     struct timerblock *t = FROM_SYSBUS(typeof (*t), dev);
 194     unsigned int i;
 195     int timer_regs, freq_hz;
 196
 197     /* All timers share a single irq line.  */
 198     sysbus_init_irq(dev, &t->irq);
 199
 200     /* Init all the ptimers.  */
 201     freq_hz = qdev_get_prop_int(&dev->qdev, "frequency", 2);
 202     t->nr_timers = qdev_get_prop_int(&dev->qdev, "nr-timers", 2);
 203     t->timers = qemu_mallocz(sizeof t->timers[0] * t->nr_timers);
 204     for (i = 0; i < t->nr_timers; i++) {
 205         struct xlx_timer *xt = &t->timers[i];
 206
 207         xt->parent = t;
 208         xt->nr = i;
 209         xt->bh = qemu_bh_new(timer_hit, xt);
 210         xt->ptimer = ptimer_init(xt->bh);
 211         ptimer_set_freq(xt->ptimer, freq_hz);
 212     }
 213
 214     timer_regs = cpu_register_io_memory(0, timer_read, timer_write, t);
 215     sysbus_init_mmio(dev, R_MAX * 4 * t->nr_timers, timer_regs);
 216 }
 217
 218 static void xilinx_timer_register(void)
 219 {
 220     sysbus_register_dev("xilinx,timer", sizeof (struct timerblock),
 221                         xilinx_timer_init);
 222 }
 223
 224 device_init(xilinx_timer_register)