hw/timer: Introduce ARM A9 Global Timer.

The ARM A9 MPCore has a timer that is global to all cores in the cluster.
The timer is shared but each core has a private independent comparator
and interrupt.

Based on version contributed by Francois LEGAL.

Signed-off-by: François LEGAL <devel@thom.fr.eu.org>
Message-id: 4918e89476b8da916be2964ec41578b50d569a37.1385969450.git.peter.crosthwaite@xilinx.com
[PC changes:
 * New commit message
 * Re-implemented as single timer model
 * Fixed backwards counting issue in polled mode
 * completed VMSD fields
 * macroified magic numbers (and headerified reg definitions)
 * split of as device-model-only patch
 * use bitops for 64 bit register access
 * Fixed auto increment mode to check condition properly
 * general cleanup (names/style etc).
]
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
[PMM:
 * minor typo fixes
 * added missing return after error_setg()
 * dropped setting dc->no_user = 1
]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 97 insertions, 0 deletions

diff --git a/include/hw/timer/a9gtimer.h b/include/hw/timer/a9gtimer.h
new file mode 100644
index 0000000000..b88c02a6ef
--- /dev/null
+++ b/include/hw/timer/a9gtimer.h
@@ -0,0 +1,97 @@
+/*
+ * Global peripheral timer block for ARM A9MP
+ *
+ * (C) 2013 Xilinx Inc.
+ *
+ * Written by François LEGAL
+ * Written by Peter Crosthwaite <peter.crosthwaite@xilinx.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef HW_TIMER_A9_GTIMER_H_H
+#define HW_TIMER_A9_GTIMER_H_H
+
+#include "hw/sysbus.h"
+
+#define A9_GTIMER_MAX_CPUS 4
+
+#define TYPE_A9_GTIMER "arm.cortex-a9-global-timer"
+#define A9_GTIMER(obj) OBJECT_CHECK(A9GTimerState, (obj), TYPE_A9_GTIMER)
+
+#define R_COUNTER_LO                0x00
+#define R_COUNTER_HI                0x04
+
+#define R_CONTROL                   0x08
+#define R_CONTROL_TIMER_ENABLE      (1 << 0)
+#define R_CONTROL_COMP_ENABLE       (1 << 1)
+#define R_CONTROL_IRQ_ENABLE        (1 << 2)
+#define R_CONTROL_AUTO_INCREMENT    (1 << 2)
+#define R_CONTROL_PRESCALER_SHIFT   8
+#define R_CONTROL_PRESCALER_LEN     8
+#define R_CONTROL_PRESCALER_MASK    (((1 << R_CONTROL_PRESCALER_LEN) - 1) << \
+                                     R_CONTROL_PRESCALER_SHIFT)
+
+#define R_CONTROL_BANKED            (R_CONTROL_COMP_ENABLE | \
+                                     R_CONTROL_IRQ_ENABLE | \
+                                     R_CONTROL_AUTO_INCREMENT)
+#define R_CONTROL_NEEDS_SYNC        (R_CONTROL_TIMER_ENABLE | \
+                                     R_CONTROL_PRESCALER_MASK)
+
+#define R_INTERRUPT_STATUS          0x0C
+#define R_COMPARATOR_LO             0x10
+#define R_COMPARATOR_HI             0x14
+#define R_AUTO_INCREMENT            0x18
+
+typedef struct A9GTimerPerCPU A9GTimerPerCPU;
+typedef struct A9GTimerState A9GTimerState;
+
+struct A9GTimerPerCPU {
+    A9GTimerState *parent;
+
+    uint32_t control; /* only per cpu banked bits valid */
+    uint64_t compare;
+    uint32_t status;
+    uint32_t inc;
+
+    MemoryRegion iomem;
+    qemu_irq irq; /* PPI interrupts */
+};
+
+struct A9GTimerState {
+    /*< private >*/
+    SysBusDevice parent_obj;
+    /*< public >*/
+
+    MemoryRegion iomem;
+    /* static props */
+    uint32_t num_cpu;
+
+    QEMUTimer *timer;
+
+    uint64_t counter; /* current timer value */
+
+    uint64_t ref_counter;
+    uint64_t cpu_ref_time; /* the cpu time as of last update of ref_counter */
+    uint32_t control; /* only non per cpu banked bits valid */
+
+    A9GTimerPerCPU per_cpu[A9_GTIMER_MAX_CPUS];
+};
+
+typedef struct A9GTimerUpdate {
+    uint64_t now;
+    uint64_t new;
+} A9GTimerUpdate;
+
+#endif /* #ifdef HW_TIMER_A9_GTIMER_H_H */