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[PULL,01/37] integrator/cp: add support for REFCNT register

Message ID 1386686613-2390-2-git-send-email-peter.maydell@linaro.org
State New
Headers show

Commit Message

Peter Maydell Dec. 10, 2013, 2:42 p.m. UTC 
From: Jan Petrous <jan.petrous@tieto.com>

Linux kernel from version 3.4 requires CM_REFCNT register for sched timer
for Integrator/CP board (integrator_defconfig).

See http://infocenter.arm.com/help/topic/com.arm.doc.dui0138e/ch04s06s11.html

Signed-off-by: Jan Petrous <jan.petrous@tieto.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/integratorcp.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)
diff mbox

Patch

diff --git a/hw/arm/integratorcp.c b/hw/arm/integratorcp.c
index c44b2a4..a759689 100644
--- a/hw/arm/integratorcp.c
+++ b/hw/arm/integratorcp.c
@@ -36,6 +36,7 @@  typedef struct IntegratorCMState {
     uint32_t cm_init;
     uint32_t cm_flags;
     uint32_t cm_nvflags;
+    uint32_t cm_refcnt_offset;
     uint32_t int_level;
     uint32_t irq_enabled;
     uint32_t fiq_enabled;
@@ -82,9 +83,13 @@  static uint64_t integratorcm_read(void *opaque, hwaddr offset,
         return s->cm_sdram;
     case 9: /* CM_INIT */
         return s->cm_init;
-    case 10: /* CM_REFCT */
-        /* ??? High frequency timer.  */
-        hw_error("integratorcm_read: CM_REFCT");
+    case 10: /* CM_REFCNT */
+        /* This register, CM_REFCNT, provides a 32-bit count value.
+         * The count increments at the fixed reference clock frequency of 24MHz
+         * and can be used as a real-time counter.
+         */
+        return (uint32_t)muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), 24,
+                                  1000) - s->cm_refcnt_offset;
     case 12: /* CM_FLAGS */
         return s->cm_flags;
     case 14: /* CM_NVFLAGS */
@@ -257,6 +262,8 @@  static int integratorcm_init(SysBusDevice *dev)
     }
     memcpy(integrator_spd + 73, "QEMU-MEMORY", 11);
     s->cm_init = 0x00000112;
+    s->cm_refcnt_offset = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), 24,
+                                   1000);
     memory_region_init_ram(&s->flash, OBJECT(s), "integrator.flash", 0x100000);
     vmstate_register_ram_global(&s->flash);