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Soby Mathew0d786072016-03-24 16:56:29 +00001/*
2 * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * Neither the name of ARM nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without specific
16 * prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <arch.h>
32#include <assert.h>
33#include <platform.h>
34#include <psci.h>
35
36/*
37 * The PSCI generic code uses this API to let the platform participate in state
38 * coordination during a power management operation. It compares the platform
39 * specific local power states requested by each cpu for a given power domain
40 * and returns the coordinated target power state that the domain should
41 * enter. A platform assigns a number to a local power state. This default
42 * implementation assumes that the platform assigns these numbers in order of
43 * increasing depth of the power state i.e. for two power states X & Y, if X < Y
44 * then X represents a shallower power state than Y. As a result, the
45 * coordinated target local power state for a power domain will be the minimum
46 * of the requested local power states.
47 */
48plat_local_state_t plat_get_target_pwr_state(unsigned int lvl,
49 const plat_local_state_t *states,
50 unsigned int ncpu)
51{
52 plat_local_state_t target = PLAT_MAX_OFF_STATE, temp;
53
54 assert(ncpu);
55
56 do {
57 temp = *states++;
58 if (temp < target)
59 target = temp;
60 } while (--ncpu);
61
62 return target;
63}