[PATCH v3 5/5] hw/intc: ibex_timer: Convert the timer to use RISC-V CPU GPIO lines

[Alistair Francis <alistair.francis@opensource.wdc.com>]

From: Alistair Francis <alistair.francis@wdc.com>

Instead of using riscv_cpu_update_mip() let's instead use the new RISC-V
CPU GPIO lines to set the timer MIP bits.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/hw/timer/ibex_timer.h |  2 ++
 hw/riscv/opentitan.c          |  3 +++
 hw/timer/ibex_timer.c         | 17 ++++++++++++-----
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/include/hw/timer/ibex_timer.h b/include/hw/timer/ibex_timer.h
index 6a43537003..b6f69b38ee 100644
--- a/include/hw/timer/ibex_timer.h
+++ b/include/hw/timer/ibex_timer.h
@@ -48,5 +48,7 @@ struct IbexTimerState {
     uint32_t timebase_freq;
 
     qemu_irq irq;
+
+    qemu_irq m_timer_irq;
 };
 #endif /* HW_IBEX_TIMER_H */
diff --git a/hw/riscv/opentitan.c b/hw/riscv/opentitan.c
index 048aced0ec..f7cfcf1c3a 100644
--- a/hw/riscv/opentitan.c
+++ b/hw/riscv/opentitan.c
@@ -183,6 +183,9 @@ static void lowrisc_ibex_soc_realize(DeviceState *dev_soc, Error **errp)
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->timer),
                        0, qdev_get_gpio_in(DEVICE(&s->plic),
                        IBEX_TIMER_TIMEREXPIRED0_0));
+    qdev_connect_gpio_out(DEVICE(&s->timer), 0,
+                          qdev_get_gpio_in(DEVICE(qemu_get_cpu(0)),
+                                           IRQ_M_TIMER));
 
     create_unimplemented_device("riscv.lowrisc.ibex.gpio",
         memmap[IBEX_DEV_GPIO].base, memmap[IBEX_DEV_GPIO].size);
diff --git a/hw/timer/ibex_timer.c b/hw/timer/ibex_timer.c
index 5befb53506..66e1f8e48c 100644
--- a/hw/timer/ibex_timer.c
+++ b/hw/timer/ibex_timer.c
@@ -77,7 +77,7 @@ static void ibex_timer_update_irqs(IbexTimerState *s)
         /*
          * If the mtimecmp was in the past raise the interrupt now.
          */
-        riscv_cpu_update_mip(cpu, MIP_MTIP, BOOL_TO_MASK(1));
+        qemu_irq_raise(s->m_timer_irq);
         if (s->timer_intr_enable & R_INTR_ENABLE_IE_0_MASK) {
             s->timer_intr_state |= R_INTR_STATE_IS_0_MASK;
             qemu_set_irq(s->irq, true);
@@ -86,7 +86,7 @@ static void ibex_timer_update_irqs(IbexTimerState *s)
     }
 
     /* Setup a timer to trigger the interrupt in the future */
-    riscv_cpu_update_mip(cpu, MIP_MTIP, BOOL_TO_MASK(0));
+    qemu_irq_lower(s->m_timer_irq);
     qemu_set_irq(s->irq, false);
 
     diff = cpu->env.timecmp - now;
@@ -106,10 +106,8 @@ static void ibex_timer_update_irqs(IbexTimerState *s)
 static void ibex_timer_cb(void *opaque)
 {
     IbexTimerState *s = opaque;
-    CPUState *cs = qemu_get_cpu(0);
-    RISCVCPU *cpu = RISCV_CPU(cs);
 
-    riscv_cpu_update_mip(cpu, MIP_MTIP, BOOL_TO_MASK(1));
+    qemu_irq_raise(s->m_timer_irq);
     if (s->timer_intr_enable & R_INTR_ENABLE_IE_0_MASK) {
         s->timer_intr_state |= R_INTR_STATE_IS_0_MASK;
         qemu_set_irq(s->irq, true);
@@ -280,12 +278,21 @@ static void ibex_timer_init(Object *obj)
     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
 }
 
+static void ibex_timer_realize(DeviceState *dev, Error **errp)
+{
+    IbexTimerState *s = IBEX_TIMER(dev);
+
+    qdev_init_gpio_out(dev, &s->m_timer_irq, 1);
+}
+
+
 static void ibex_timer_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->reset = ibex_timer_reset;
     dc->vmsd = &vmstate_ibex_timer;
+    dc->realize = ibex_timer_realize;
     device_class_set_props(dc, ibex_timer_properties);
 }
 
-- 
2.31.1