arm_pm.c

/*
 * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
 *
 * 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 ARM 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 HOLDER 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.
 */

#include <arch_helpers.h>
#include <assert.h>
#include <errno.h>
#include <psci.h>

/*******************************************************************************
 * ARM standard platform handler called to check the validity of the power state
 * parameter.
 ******************************************************************************/
int arm_validate_power_state(unsigned int power_state,
			    psci_power_state_t *req_state)
{
	int pstate = psci_get_pstate_type(power_state);
	int pwr_lvl = psci_get_pstate_pwrlvl(power_state);
	int i;

	assert(req_state);

	if (pwr_lvl > PLAT_MAX_PWR_LVL)
		return PSCI_E_INVALID_PARAMS;

	/* Sanity check the requested state */
	if (pstate == PSTATE_TYPE_STANDBY) {
		/*
		 * It's possible to enter standby only on power level 0
		 * Ignore any other power level.
		 */
		if (pwr_lvl != ARM_PWR_LVL0)
			return PSCI_E_INVALID_PARAMS;

		req_state->pwr_domain_state[ARM_PWR_LVL0] =
					ARM_LOCAL_STATE_RET;
	} else {
		for (i = ARM_PWR_LVL0; i <= pwr_lvl; i++)
			req_state->pwr_domain_state[i] =
					ARM_LOCAL_STATE_OFF;
	}

	/*
	 * We expect the 'state id' to be zero.
	 */
	if (psci_get_pstate_id(power_state))
		return PSCI_E_INVALID_PARAMS;

	return PSCI_E_SUCCESS;
}