[Qemu-devel] [PATCH v9 2/4] cadence_ttc: initial version of device model

[Peter A. G. Crosthwaite]

Implemented cadence Triple Timer Counter (TCC)

Signed-off-by: Peter A. G. Crosthwaite <address@hidden>
Signed-off-by: John Linn <address@hidden>
Acked-by: Edgar E. Iglesias <address@hidden>
---
changed from v8:
implemented vmsd
changed from v7:
removed fflush() from DBPRINTF
changed from v6:
renamed cadence_ttc_state -> CadenceTTCState
renamed qemu_debug() -> DB_PRINT (all)
added reset function
changed from v4:
fixed FSF addess
changed device_init -> type_init
changed from v3:
Fixed race condition where timer could miss match events on wrap around
changed from v2:
changed ptimer to QEMUTimer (Fixed skew/drift issue in timer delays)
changes from v1:
refactored event driven code
marked vmsd as unmigratable
 Makefile.target  |    1 +
 hw/cadence_ttc.c |  489 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 490 insertions(+), 0 deletions(-)
 create mode 100644 hw/cadence_ttc.c

diff --git a/Makefile.target b/Makefile.target
index d5f6c9e..18ae103 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -346,6 +346,7 @@ obj-arm-y = integratorcp.o versatilepb.o arm_pic.o 
arm_timer.o
 obj-arm-y += arm_boot.o pl011.o pl031.o pl050.o pl080.o pl110.o pl181.o pl190.o
 obj-arm-y += versatile_pci.o
 obj-arm-y += cadence_uart.o
+obj-arm-y += cadence_ttc.o
 obj-arm-y += realview_gic.o realview.o arm_sysctl.o arm11mpcore.o a9mpcore.o
 obj-arm-y += exynos4210_gic.o exynos4210_combiner.o exynos4210.o
 obj-arm-y += exynos4_boards.o exynos4210_uart.o exynos4210_pwm.o
diff --git a/hw/cadence_ttc.c b/hw/cadence_ttc.c
new file mode 100644
index 0000000..2b5477b
--- /dev/null
+++ b/hw/cadence_ttc.c
@@ -0,0 +1,489 @@
+/*
+ * Xilinx Zynq cadence TTC model
+ *
+ * Copyright (c) 2011 Xilinx Inc.
+ * Copyright (c) 2012 Peter A.G. Crosthwaite (address@hidden)
+ * Copyright (c) 2012 PetaLogix Pty Ltd.
+ * Written By Haibing Ma
+ *            M. Habib
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "sysbus.h"
+#include "qemu-timer.h"
+
+#ifdef CADENCE_TTC_ERR_DEBUG
+#define DB_PRINT(...) do { \
+    fprintf(stderr,  ": %s: ", __func__); \
+    fprintf(stderr, ## __VA_ARGS__); \
+    } while (0);
+#else
+    #define DB_PRINT(...)
+#endif
+
+#define COUNTER_INTR_IV     0x00000001
+#define COUNTER_INTR_M1     0x00000002
+#define COUNTER_INTR_M2     0x00000004
+#define COUNTER_INTR_M3     0x00000008
+#define COUNTER_INTR_OV     0x00000010
+#define COUNTER_INTR_EV     0x00000020
+
+#define COUNTER_CTRL_DIS    0x00000001
+#define COUNTER_CTRL_INT    0x00000002
+#define COUNTER_CTRL_DEC    0x00000004
+#define COUNTER_CTRL_MATCH  0x00000008
+#define COUNTER_CTRL_RST    0x00000010
+
+#define CLOCK_CTRL_PS_EN    0x00000001
+#define CLOCK_CTRL_PS_V     0x0000001e
+
+typedef struct {
+    QEMUTimer *timer;
+    int freq;
+
+    uint32_t reg_clock;
+    uint32_t reg_count;
+    uint32_t reg_value;
+    uint16_t reg_interval;
+    uint16_t reg_match[3];
+    uint32_t reg_intr;
+    uint32_t reg_intr_en;
+    uint32_t reg_event_ctrl;
+    uint32_t reg_event;
+
+    uint64_t cpu_time;
+    unsigned int cpu_time_valid;
+
+    qemu_irq irq;
+} CadenceTimerState;
+
+typedef struct {
+    SysBusDevice busdev;
+    MemoryRegion iomem;
+    CadenceTimerState timer[3];
+} CadenceTTCState;
+
+static void cadence_timer_update(CadenceTimerState *s)
+{
+    qemu_set_irq(s->irq, !!(s->reg_intr & s->reg_intr_en));
+}
+
+static CadenceTimerState *cadence_timer_from_addr(void *opaque,
+                                        target_phys_addr_t offset)
+{
+    unsigned int index;
+    CadenceTTCState *s = (CadenceTTCState *)opaque;
+
+    index = (offset >> 2) % 3;
+
+    return &s->timer[index];
+}
+
+static uint64_t cadence_timer_get_ns(CadenceTimerState *s, uint64_t 
timer_steps)
+{
+    /* timer_steps has max value of 0x100000000. double check it
+     * (or overflow can happen below) */
+    assert(timer_steps <= 1ULL << 32);
+
+    uint64_t r = timer_steps * 1000000000ULL;
+    if (s->reg_clock & CLOCK_CTRL_PS_EN) {
+        r >>= 16 - (((s->reg_clock & CLOCK_CTRL_PS_V) >> 1) + 1);
+    } else {
+        r >>= 16;
+    }
+    r /= (uint64_t)s->freq;
+    return r;
+}
+
+static uint64_t cadence_timer_get_steps(CadenceTimerState *s, uint64_t ns)
+{
+    uint64_t to_divide = 1000000000ULL;
+
+    uint64_t r = ns;
+     /* for very large intervals (> 8s) do some division first to stop
+      * overflow (costs some prescision) */
+    while (r >= 8ULL << 30 && to_divide > 1) {
+        r /= 1000;
+        to_divide /= 1000;
+    }
+    r <<= 16;
+    /* keep early-dividing as needed */
+    while (r >= 8ULL << 30 && to_divide > 1) {
+        r /= 1000;
+        to_divide /= 1000;
+    }
+    r *= (uint64_t)s->freq;
+    if (s->reg_clock & CLOCK_CTRL_PS_EN) {
+        r /= 1 << (((s->reg_clock & CLOCK_CTRL_PS_V) >> 1) + 1);
+    }
+
+    r /= to_divide;
+    return r;
+}
+
+/* determine if x is in between a and b, exclusive of a, inclusive of b */
+
+static inline int64_t is_between(int64_t x, int64_t a, int64_t b)
+{
+    if (a < b) {
+        return x > a && x <= b;
+    }
+    return x < a && x >= b;
+}
+
+static void cadence_timer_run(CadenceTimerState *s)
+{
+    int i;
+    int64_t event_interval, next_value;
+
+    assert(s->cpu_time_valid); /* cadence_timer_sync must be called first */
+
+    if (s->reg_count & COUNTER_CTRL_DIS) {
+        s->cpu_time_valid = 0;
+        return;
+    }
+
+    { /* figure out what's going to happen next (rollover or match) */
+        int64_t interval = (uint64_t)((s->reg_count & COUNTER_CTRL_INT) ?
+                (int64_t)s->reg_interval + 1 : 0x10000ULL) << 16;
+        next_value = (s->reg_count & COUNTER_CTRL_DEC) ? -1ULL : interval;
+        for (i = 0; i < 3; ++i) {
+            int64_t cand = (uint64_t)s->reg_match[i] << 16;
+            if (is_between(cand, (uint64_t)s->reg_value, next_value)) {
+                next_value = cand;
+            }
+        }
+    }
+    DB_PRINT("next timer event value: %09llx\n",
+            (unsigned long long)next_value);
+
+    event_interval = next_value - (int64_t)s->reg_value;
+    event_interval = (event_interval < 0) ? -event_interval : event_interval;
+
+    qemu_mod_timer(s->timer, s->cpu_time +
+                cadence_timer_get_ns(s, event_interval));
+}
+
+static void cadence_timer_sync(CadenceTimerState *s)
+{
+    int i;
+    int64_t r, x;
+    int64_t interval = ((s->reg_count & COUNTER_CTRL_INT) ?
+            (int64_t)s->reg_interval + 1 : 0x10000ULL) << 16;
+    uint64_t old_time = s->cpu_time;
+
+    s->cpu_time = qemu_get_clock_ns(vm_clock);
+    DB_PRINT("cpu time: %lld ns\n", (long long)old_time);
+
+    if (!s->cpu_time_valid || old_time == s->cpu_time) {
+        s->cpu_time_valid = 1;
+        return;
+    }
+
+    r = (int64_t)cadence_timer_get_steps(s, s->cpu_time - old_time);
+    x = (int64_t)s->reg_value + ((s->reg_count & COUNTER_CTRL_DEC) ? -r : r);
+
+    for (i = 0; i < 3; ++i) {
+        int64_t m = (int64_t)s->reg_match[i] << 16;
+        if (m > interval) {
+            continue;
+        }
+        /* check to see if match event has occurred. check m +/- interval
+         * to account for match events in wrap around cases */
+        if (is_between(m, s->reg_value, x) ||
+            is_between(m + interval, s->reg_value, x) ||
+            is_between(m - interval, s->reg_value, x)) {
+            s->reg_intr |= (2 << i);
+        }
+    }
+    while (x < 0) {
+        x += interval;
+    }
+    s->reg_value = (uint32_t)(x % interval);
+
+    if (s->reg_value != x) {
+        s->reg_intr |= (s->reg_count & COUNTER_CTRL_INT) ?
+            COUNTER_INTR_IV : COUNTER_INTR_OV;
+    }
+    cadence_timer_update(s);
+}
+
+static void cadence_timer_tick(void *opaque)
+{
+    CadenceTimerState *s = opaque;
+
+    DB_PRINT("\n");
+    cadence_timer_sync(s);
+    cadence_timer_run(s);
+}
+
+static uint32_t cadence_ttc_read_imp(void *opaque, target_phys_addr_t offset)
+{
+    CadenceTimerState *s = cadence_timer_from_addr(opaque, offset);
+    uint32_t value;
+
+    cadence_timer_sync(s);
+    cadence_timer_run(s);
+
+    switch (offset) {
+    case 0x00: /* clock control */
+    case 0x04:
+    case 0x08:
+        return s->reg_clock;
+
+    case 0x0c: /* counter control */
+    case 0x10:
+    case 0x14:
+        return s->reg_count;
+
+    case 0x18: /* counter value */
+    case 0x1c:
+    case 0x20:
+        return (uint16_t)(s->reg_value >> 16);
+
+    case 0x24: /* reg_interval counter */
+    case 0x28:
+    case 0x2c:
+        return s->reg_interval;
+
+    case 0x30: /* match 1 counter */
+    case 0x34:
+    case 0x38:
+        return s->reg_match[0];
+
+    case 0x3c: /* match 2 counter */
+    case 0x40:
+    case 0x44:
+        return s->reg_match[1];
+
+    case 0x48: /* match 3 counter */
+    case 0x4c:
+    case 0x50:
+        return s->reg_match[2];
+
+    case 0x54: /* interrupt register */
+    case 0x58:
+    case 0x5c:
+        /* cleared after read */
+        value = s->reg_intr;
+        s->reg_intr = 0;
+        return value;
+
+    case 0x60: /* interrupt enable */
+    case 0x64:
+    case 0x68:
+        return s->reg_intr_en;
+
+    case 0x6c:
+    case 0x70:
+    case 0x74:
+        return s->reg_event_ctrl;
+
+    case 0x78:
+    case 0x7c:
+    case 0x80:
+        return s->reg_event;
+
+    default:
+        return 0;
+    }
+}
+
+static uint64_t cadence_ttc_read(void *opaque, target_phys_addr_t offset,
+    unsigned size)
+{
+    uint32_t ret = cadence_ttc_read_imp(opaque, offset);
+
+    DB_PRINT("addr: %08x data: %08x\n", offset, ret);
+    return ret;
+}
+
+static void cadence_ttc_write(void *opaque, target_phys_addr_t offset,
+        uint64_t value, unsigned size)
+{
+    CadenceTimerState *s = cadence_timer_from_addr(opaque, offset);
+
+    DB_PRINT("addr: %08x data %08x\n", offset, (unsigned)value);
+
+    cadence_timer_sync(s);
+
+    switch (offset) {
+    case 0x00: /* clock control */
+    case 0x04:
+    case 0x08:
+        s->reg_clock = value & 0x3F;
+        break;
+
+    case 0x0c: /* counter control */
+    case 0x10:
+    case 0x14:
+        if (value & COUNTER_CTRL_RST) {
+            s->reg_value = 0;
+        }
+        s->reg_count = value & 0x3f & ~COUNTER_CTRL_RST;
+        break;
+
+    case 0x24: /* interval register */
+    case 0x28:
+    case 0x2c:
+        s->reg_interval = value & 0xffff;
+        break;
+
+    case 0x30: /* match register */
+    case 0x34:
+    case 0x38:
+        s->reg_match[0] = value & 0xffff;
+
+    case 0x3c: /* match register */
+    case 0x40:
+    case 0x44:
+        s->reg_match[1] = value & 0xffff;
+
+    case 0x48: /* match register */
+    case 0x4c:
+    case 0x50:
+        s->reg_match[2] = value & 0xffff;
+        break;
+
+    case 0x54: /* interrupt register */
+    case 0x58:
+    case 0x5c:
+        s->reg_intr &= (~value & 0xfff);
+        break;
+
+    case 0x60: /* interrupt enable */
+    case 0x64:
+    case 0x68:
+        s->reg_intr_en = value & 0x3f;
+        break;
+
+    case 0x6c: /* event control */
+    case 0x70:
+    case 0x74:
+        s->reg_event_ctrl = value & 0x07;
+        break;
+
+    default:
+        return;
+    }
+
+    cadence_timer_run(s);
+    cadence_timer_update(s);
+}
+
+static const MemoryRegionOps cadence_ttc_ops = {
+    .read = cadence_ttc_read,
+    .write = cadence_ttc_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static void cadence_timer_reset(CadenceTimerState *s)
+{
+   s->reg_count = 0x21;
+}
+
+static void cadence_timer_init(uint32_t freq, CadenceTimerState *s)
+{
+    memset(s, 0, sizeof(CadenceTimerState));
+    s->freq = freq;
+
+    cadence_timer_reset(s);
+
+    s->timer = qemu_new_timer_ns(vm_clock, cadence_timer_tick, s);
+}
+
+static int cadence_ttc_init(SysBusDevice *dev)
+{
+    CadenceTTCState *s = FROM_SYSBUS(CadenceTTCState, dev);
+    int i;
+
+    for (i = 0; i < 3; ++i) {
+        cadence_timer_init(2500000, &s->timer[i]);
+        sysbus_init_irq(dev, &s->timer[i].irq);
+    }
+
+    memory_region_init_io(&s->iomem, &cadence_ttc_ops, s, "timer", 0x1000);
+    sysbus_init_mmio(dev, &s->iomem);
+
+    return 0;
+}
+
+static void cadence_timer_pre_save(void *opaque)
+{
+    cadence_timer_sync((CadenceTimerState *)opaque);
+}
+
+static int cadence_timer_post_load(void *opaque, int version_id)
+{
+    CadenceTimerState *s = opaque;
+
+    s->cpu_time_valid = 0;
+    cadence_timer_sync(s);
+    cadence_timer_run(s);
+    cadence_timer_update(s);
+    return 0;
+}
+
+static const VMStateDescription vmstate_cadence_timer = {
+    .name = "cadence_timer",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .pre_save = cadence_timer_pre_save,
+    .post_load = cadence_timer_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(reg_clock, CadenceTimerState),
+        VMSTATE_UINT32(reg_count, CadenceTimerState),
+        VMSTATE_UINT32(reg_value, CadenceTimerState),
+        VMSTATE_UINT16(reg_interval, CadenceTimerState),
+        VMSTATE_UINT16_ARRAY(reg_match, CadenceTimerState, 3),
+        VMSTATE_UINT32(reg_intr, CadenceTimerState),
+        VMSTATE_UINT32(reg_intr_en, CadenceTimerState),
+        VMSTATE_UINT32(reg_event_ctrl, CadenceTimerState),
+        VMSTATE_UINT32(reg_event, CadenceTimerState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_cadence_ttc = {
+    .name = "cadence_TTC",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_STRUCT_ARRAY(timer, CadenceTTCState, 3, 0,
+                            vmstate_cadence_timer,
+                            CadenceTimerState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void cadence_ttc_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
+
+    sdc->init = cadence_ttc_init;
+    dc->vmsd = &vmstate_cadence_ttc;
+}
+
+static TypeInfo cadence_ttc_info = {
+    .name  = "cadence_ttc",
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size  = sizeof(CadenceTTCState),
+    .class_init = cadence_ttc_class_init,
+};
+
+static void cadence_ttc_register_types(void)
+{
+    type_register_static(&cadence_ttc_info);
+}
+
+type_init(cadence_ttc_register_types)
-- 
1.7.3.2