xilinx: Add OPB timer.

Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@gmail.com>

hw/xilinx_timer.c

+/*
+ * QEMU model of the Xilinx timer block.
+ *
+ * Copyright (c) 2009 Edgar E. Iglesias.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "sysbus.h"
+#include "sysemu.h"
+#include "qemu-timer.h"
+
+#define D(x)
+
+#define R_TCSR     0
+#define R_TLR      1
+#define R_TCR      2
+#define R_MAX      4
+
+#define TCSR_MDT        (1<<0)
+#define TCSR_UDT        (1<<1)
+#define TCSR_GENT       (1<<2)
+#define TCSR_CAPT       (1<<3)
+#define TCSR_ARHT       (1<<4)
+#define TCSR_LOAD       (1<<5)
+#define TCSR_ENIT       (1<<6)
+#define TCSR_ENT        (1<<7)
+#define TCSR_TINT       (1<<8)
+#define TCSR_PWMA       (1<<9)
+#define TCSR_ENALL      (1<<10)
+
+struct xlx_timer
+{
+    QEMUBH *bh;
+    ptimer_state *ptimer;
+    void *parent;
+    int nr; /* for debug.  */
+
+    unsigned long timer_div;
+
+    uint32_t regs[R_MAX];
+};
+
+struct timerblock
+{
+    SysBusDevice busdev;
+    qemu_irq irq;
+    unsigned int nr_timers;
+    struct xlx_timer *timers;
+};
+
+static inline unsigned int timer_from_addr(target_phys_addr_t addr)
+{
+    /* Timers get a 4x32bit control reg area each.  */
+    return addr >> 2;
+}
+
+static void timer_update_irq(struct timerblock *t)
+{
+    unsigned int i, irq = 0;
+    uint32_t csr;
+
+    for (i = 0; i < t->nr_timers; i++) {
+        csr = t->timers[i].regs[R_TCSR];
+        irq |= (csr & TCSR_TINT) && (csr & TCSR_ENIT);
+    }
+
+    /* All timers within the same slave share a single IRQ line.  */
+    qemu_set_irq(t->irq, !!irq);
+}
+
+static uint32_t timer_readl (void *opaque, target_phys_addr_t addr)
+{
+    struct timerblock *t = opaque;
+    struct xlx_timer *xt;
+    uint32_t r = 0;
+    unsigned int timer;
+
+    addr >>= 2;
+    timer = timer_from_addr(addr);
+    xt = &t->timers[timer];
+    /* Further decoding to address a specific timers reg.  */
+    addr &= 0x3;
+    switch (addr)
+    {
+        case R_TCR:
+                r = ptimer_get_count(xt->ptimer);
+                if (!(xt->regs[R_TCSR] & TCSR_UDT))
+                    r = ~r;
+                D(qemu_log("xlx_timer t=%d read counter=%x udt=%d\n",
+                         timer, r, xt->regs[R_TCSR] & TCSR_UDT));
+            break;
+        default:
+            if (addr < ARRAY_SIZE(xt->regs))
+                r = xt->regs[addr];
+            break;
+
+    }
+    D(printf("%s timer=%d %x=%x\n", __func__, timer, addr * 4, r));
+    return r;
+}
+
+static void timer_enable(struct xlx_timer *xt)
+{
+    uint64_t count;
+
+    D(printf("%s timer=%d down=%d\n", __func__,
+              xt->nr, xt->regs[R_TCSR] & TCSR_UDT));
+
+    ptimer_stop(xt->ptimer);
+
+    if (xt->regs[R_TCSR] & TCSR_UDT)
+        count = xt->regs[R_TLR];
+    else
+        count = ~0 - xt->regs[R_TLR];
+    ptimer_set_count(xt->ptimer, count);
+    ptimer_run(xt->ptimer, 1);
+}
+
+static void
+timer_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
+{
+    struct timerblock *t = opaque;
+    struct xlx_timer *xt;
+    unsigned int timer;
+
+    addr >>= 2;
+    timer = timer_from_addr(addr);
+    xt = &t->timers[timer];
+    D(printf("%s addr=%x val=%x (timer=%d off=%d)\n",
+             __func__, addr * 4, value, timer, addr & 3));
+    /* Further decoding to address a specific timers reg.  */
+    addr &= 3;
+    switch (addr) 
+    {
+        case R_TCSR:
+            if (value & TCSR_TINT)
+                value &= ~TCSR_TINT;
+
+            xt->regs[addr] = value;
+            if (value & TCSR_ENT)
+                timer_enable(xt);
+            break;
+ 
+        default:
+            if (addr < ARRAY_SIZE(xt->regs))
+                xt->regs[addr] = value;
+            break;
+    }
+    timer_update_irq(t);
+}
+
+static CPUReadMemoryFunc *timer_read[] = {
+    NULL, NULL,
+    &timer_readl,
+};
+
+static CPUWriteMemoryFunc *timer_write[] = {
+    NULL, NULL,
+    &timer_writel,
+};
+
+static void timer_hit(void *opaque)
+{
+    struct xlx_timer *xt = opaque;
+    struct timerblock *t = xt->parent;
+    D(printf("%s %d\n", __func__, timer));
+    xt->regs[R_TCSR] |= TCSR_TINT;
+
+    if (xt->regs[R_TCSR] & TCSR_ARHT)
+        timer_enable(xt);
+    timer_update_irq(t);
+}
+
+static void xilinx_timer_init(SysBusDevice *dev)
+{
+    struct timerblock *t = FROM_SYSBUS(typeof (*t), dev);
+    unsigned int i;
+    int timer_regs, freq_hz;
+
+    /* All timers share a single irq line.  */
+    sysbus_init_irq(dev, &t->irq);
+
+    /* Init all the ptimers.  */
+    freq_hz = qdev_get_prop_int(&dev->qdev, "frequency", 2);
+    t->nr_timers = qdev_get_prop_int(&dev->qdev, "nr-timers", 2);
+    t->timers = qemu_mallocz(sizeof t->timers[0] * t->nr_timers);
+    for (i = 0; i < t->nr_timers; i++) {
+        struct xlx_timer *xt = &t->timers[i];
+
+        xt->parent = t;
+        xt->nr = i;
+        xt->bh = qemu_bh_new(timer_hit, xt);
+        xt->ptimer = ptimer_init(xt->bh);
+        ptimer_set_freq(xt->ptimer, freq_hz);
+    }
+
+    timer_regs = cpu_register_io_memory(0, timer_read, timer_write, t);
+    sysbus_init_mmio(dev, R_MAX * 4 * t->nr_timers, timer_regs);
+}
+
+static void xilinx_timer_register(void)
+{
+    sysbus_register_dev("xilinx,timer", sizeof (struct timerblock),
+                        xilinx_timer_init);
+}
+
+device_init(xilinx_timer_register)