power: Add voltage domains to the clock domains

This patch adds the notion of voltage domains, and groups clock
domains that operate under the same voltage (i.e. power supply) into
domains. Each clock domain is required to be associated with a voltage
domain, and the latter requires the voltage to be explicitly set.

A voltage domain is an independently controllable voltage supply being
provided to section of the design. Thus, if you wish to perform
dynamic voltage scaling on a CPU, its clock domain should be
associated with a separate voltage domain.

The current implementation of the voltage domain does not take into
consideration cases where there are derived voltage domains running at
ratio of native voltage domains, as with the case where there can be
on-chip buck/boost (charge pumps) voltage regulation logic.

The regression and configuration scripts are updated with a generic
voltage domain for the system, and one for the CPUs.

1 files changed, 84 insertions, 0 deletions

diff --git a/src/sim/voltage_domain.hh b/src/sim/voltage_domain.hh
new file mode 100644
index 000000000..585ec8d66
--- /dev/null
+++ b/src/sim/voltage_domain.hh
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2012 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Vasileios Spiliopoulos
+ *          Akash Bagdia
+ */
+
+#ifndef __SIM_VOLTAGE_DOMAIN_HH__
+#define __SIM_VOLTAGE_DOMAIN_HH__
+
+#include "base/statistics.hh"
+#include "params/VoltageDomain.hh"
+#include "sim/sim_object.hh"
+
+/**
+ * A VoltageDomain is used to group clock domains that operate under
+ * the same voltage. The class provides methods for setting and
+ * getting the voltage.
+ */
+class VoltageDomain : public SimObject
+{
+
+  private:
+
+    /**
+     * The voltage of the domain expressed in Volts
+     */
+    double _voltage;
+
+  public:
+
+    typedef VoltageDomainParams Params;
+    VoltageDomain(const Params *p);
+
+    /**
+     * Get the current volate.
+     *
+     * @return Voltage of the domain
+     */
+    inline double voltage() const { return _voltage; }
+
+    /**
+     * Set the voltage of the domain.
+     *
+     * @param Voltage value to be set
+     */
+    void voltage(double voltage);
+
+};
+
+#endif