[Qemu-devel] [Qemu-devel RFC v2 1/4] msf2: Add Smartfusion2 System timer

[Subbaraya Sundeep <sundeep.lkml@gmail.com>]

Modelled System Timer in Microsemi's Smartfusion2 Soc.
Timer has two 32bit down counters and two interrupts.

Signed-off-by: Subbaraya Sundeep <sundeep.lkml@gmail.com>
---
 hw/timer/Makefile.objs |   1 +
 hw/timer/msf2_timer.c  | 273 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 274 insertions(+)
 create mode 100644 hw/timer/msf2_timer.c

diff --git a/hw/timer/Makefile.objs b/hw/timer/Makefile.objs
index dd6f27e..0bdf1e1 100644
--- a/hw/timer/Makefile.objs
+++ b/hw/timer/Makefile.objs
@@ -41,3 +41,4 @@ common-obj-$(CONFIG_STM32F2XX_TIMER) += stm32f2xx_timer.o
 common-obj-$(CONFIG_ASPEED_SOC) += aspeed_timer.o
 
 common-obj-$(CONFIG_SUN4V_RTC) += sun4v-rtc.o
+common-obj-$(CONFIG_MSF2) += msf2_timer.o
diff --git a/hw/timer/msf2_timer.c b/hw/timer/msf2_timer.c
new file mode 100644
index 0000000..962ada4
--- /dev/null
+++ b/hw/timer/msf2_timer.c
@@ -0,0 +1,273 @@
+/*
+ * Timer block model of Microsemi SmartFusion2.
+ *
+ * Copyright (c) 2017 Subbaraya Sundeep <sundeep.lkml@gmail.com>.
+ *
+ * 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 "qemu/osdep.h"
+#include "hw/sysbus.h"
+#include "hw/ptimer.h"
+#include "qemu/log.h"
+#include "qemu/main-loop.h"
+
+#define D(x)
+
+#define NUM_TIMERS     2
+
+#define R_VAL          0
+#define R_LOADVAL      1
+#define R_BGLOADVAL    2
+#define R_CTRL         3
+#define R_RIS          4
+#define R_MIS          5
+#define R_MAX          6
+
+#define TIMER_CTRL_ENBL     (1 << 0)
+#define TIMER_CTRL_ONESHOT  (1 << 1)
+#define TIMER_CTRL_INTR     (1 << 2)
+#define TIMER_RIS_ACK       (1 << 0)
+#define TIMER_RST_CLR       (1 << 6)
+
+struct msf2_timer {
+    QEMUBH *bh;
+    ptimer_state *ptimer;
+    void *parent;
+    int nr; /* for debug.  */
+
+    unsigned long timer_div;
+
+    uint32_t regs[R_MAX];
+    qemu_irq irq;
+};
+
+#define TYPE_MSF2_TIMER "msf2-timer"
+#define MSF2_TIMER(obj) \
+    OBJECT_CHECK(struct timerblock, (obj), TYPE_MSF2_TIMER)
+
+struct timerblock {
+    SysBusDevice parent_obj;
+
+    MemoryRegion mmio;
+    uint32_t freq_hz;
+    struct msf2_timer *timers;
+};
+
+static inline unsigned int timer_from_addr(hwaddr addr)
+{
+    /* Timers get a 6x32bit control reg area each.  */
+    return addr / R_MAX;
+}
+
+static void timer_update_irq(struct msf2_timer *st)
+{
+    int isr;
+    int ier;
+
+    isr = !!(st->regs[R_RIS] & TIMER_RIS_ACK);
+    ier = !!(st->regs[R_CTRL] & TIMER_CTRL_INTR);
+
+    qemu_set_irq(st->irq, (ier && isr));
+}
+
+static uint64_t
+timer_read(void *opaque, hwaddr addr, unsigned int size)
+{
+    struct timerblock *t = opaque;
+    struct msf2_timer *st;
+    uint32_t r = 0;
+    unsigned int timer;
+    int isr;
+    int ier;
+
+    addr >>= 2;
+    timer = timer_from_addr(addr);
+    st = &t->timers[timer];
+
+    if (timer) {
+        addr -= 6;
+    }
+
+    switch (addr) {
+    case R_VAL:
+        r = ptimer_get_count(st->ptimer);
+        D(qemu_log("msf2_timer t=%d read counter=%x\n", timer, r));
+        break;
+
+    case R_MIS:
+        isr = !!(st->regs[R_RIS] & TIMER_RIS_ACK);
+        ier = !!(st->regs[R_CTRL] & TIMER_CTRL_INTR);
+        r = ier && isr;
+        break;
+
+    default:
+        if (addr < ARRAY_SIZE(st->regs)) {
+            r = st->regs[addr];
+        }
+        break;
+    }
+    D(fprintf(stderr, "%s timer=%d %x=%x\n", __func__, timer, addr * 4, r));
+    return r;
+}
+
+static void timer_update(struct msf2_timer *st)
+{
+    uint64_t count;
+
+    D(fprintf(stderr, "%s timer=%d\n", __func__, st->nr));
+
+    if (!(st->regs[R_CTRL] & TIMER_CTRL_ENBL)) {
+        ptimer_stop(st->ptimer);
+        return;
+    }
+
+    count = st->regs[R_LOADVAL];
+    ptimer_set_limit(st->ptimer, count, 1);
+    ptimer_run(st->ptimer, 1);
+}
+
+static void
+timer_write(void *opaque, hwaddr addr,
+            uint64_t val64, unsigned int size)
+{
+    struct timerblock *t = opaque;
+    struct msf2_timer *st;
+    unsigned int timer;
+    uint32_t value = val64;
+
+    addr >>= 2;
+    timer = timer_from_addr(addr);
+    st = &t->timers[timer];
+    D(fprintf(stderr, "%s addr=%x val=%x (timer=%d)\n",
+             __func__, addr * 4, value, timer));
+
+    if (timer) {
+        addr -= 6;
+    }
+
+    switch (addr) {
+    case R_CTRL:
+        st->regs[R_CTRL] = value;
+        timer_update(st);
+        break;
+
+    case R_RIS:
+        if (value & TIMER_RIS_ACK) {
+            st->regs[R_RIS] &= ~TIMER_RIS_ACK;
+        }
+        break;
+
+    case R_LOADVAL:
+        st->regs[R_LOADVAL] = value;
+        if (st->regs[R_CTRL] & TIMER_CTRL_ENBL) {
+            timer_update(st);
+        }
+        break;
+
+    case R_BGLOADVAL:
+        st->regs[R_BGLOADVAL] = value;
+        st->regs[R_LOADVAL] = value;
+        break;
+
+    case R_VAL:
+    case R_MIS:
+        break;
+
+    default:
+        if (addr < ARRAY_SIZE(st->regs)) {
+            st->regs[addr] = value;
+        }
+        break;
+    }
+    timer_update_irq(st);
+}
+
+static const MemoryRegionOps timer_ops = {
+    .read = timer_read,
+    .write = timer_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4
+    }
+};
+
+static void timer_hit(void *opaque)
+{
+    struct msf2_timer *st = opaque;
+    D(fprintf(stderr, "%s %d\n", __func__, st->nr));
+    st->regs[R_RIS] |= TIMER_RIS_ACK;
+
+    if (!(st->regs[R_CTRL] & TIMER_CTRL_ONESHOT)) {
+        timer_update(st);
+    }
+    timer_update_irq(st);
+}
+
+static void msf2_timer_realize(DeviceState *dev, Error **errp)
+{
+    struct timerblock *t = MSF2_TIMER(dev);
+    unsigned int i;
+
+    /* Init all the ptimers.  */
+    t->timers = g_malloc0((sizeof t->timers[0]) * NUM_TIMERS);
+    for (i = 0; i < NUM_TIMERS; i++) {
+        struct msf2_timer *st = &t->timers[i];
+
+        st->parent = t;
+        st->nr = i;
+        st->bh = qemu_bh_new(timer_hit, st);
+        st->ptimer = ptimer_init(st->bh, PTIMER_POLICY_DEFAULT);
+        ptimer_set_freq(st->ptimer, t->freq_hz);
+        sysbus_init_irq(SYS_BUS_DEVICE(dev), &st->irq);
+    }
+
+    memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t, "msf2-timer",
+                          R_MAX * 4 * NUM_TIMERS);
+    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &t->mmio);
+}
+
+static Property msf2_timer_properties[] = {
+    DEFINE_PROP_UINT32("clock-frequency", struct timerblock, freq_hz,
+                                                                83 * 1000000),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void msf2_timer_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = msf2_timer_realize;
+    dc->props = msf2_timer_properties;
+}
+
+static const TypeInfo msf2_timer_info = {
+    .name          = TYPE_MSF2_TIMER,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(struct timerblock),
+    .class_init    = msf2_timer_class_init,
+};
+
+static void msf2_timer_register_types(void)
+{
+    type_register_static(&msf2_timer_info);
+}
+
+type_init(msf2_timer_register_types)
-- 
2.5.0