/*
 * Copyright (c) 2013-2015, 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 <arm_config.h>
#include <arm_gic.h>
#include <assert.h>
#include <debug.h>
#include <errno.h>
#include <mmio.h>
#include <platform.h>
#include <plat_arm.h>
#include <psci.h>
#include <v2m_def.h>
#include "drivers/pwrc/fvp_pwrc.h"
#include "fvp_def.h"
#include "fvp_private.h"


typedef volatile struct mailbox {
	unsigned long value __aligned(CACHE_WRITEBACK_GRANULE);
} mailbox_t;

/*******************************************************************************
 * Private FVP function to program the mailbox for a cpu before it is released
 * from reset.
 ******************************************************************************/
static void fvp_program_mailbox(uint64_t mpidr, uint64_t address)
{
	uint64_t linear_id;
	mailbox_t *fvp_mboxes;

	linear_id = platform_get_core_pos(mpidr);
	fvp_mboxes = (mailbox_t *)MBOX_BASE;
	fvp_mboxes[linear_id].value = address;
	flush_dcache_range((unsigned long) &fvp_mboxes[linear_id],
			   sizeof(unsigned long));
}

/*******************************************************************************
 * Function which implements the common FVP specific operations to power down a
 * cpu in response to a CPU_OFF or CPU_SUSPEND request.
 ******************************************************************************/
static void fvp_cpu_pwrdwn_common(void)
{
	/* Prevent interrupts from spuriously waking up this cpu */
	arm_gic_cpuif_deactivate();

	/* Program the power controller to power off this cpu. */
	fvp_pwrc_write_ppoffr(read_mpidr_el1());
}

/*******************************************************************************
 * Function which implements the common FVP specific operations to power down a
 * cluster in response to a CPU_OFF or CPU_SUSPEND request.
 ******************************************************************************/
static void fvp_cluster_pwrdwn_common(void)
{
	uint64_t mpidr = read_mpidr_el1();

	/* Disable coherency if this cluster is to be turned off */
	fvp_cci_disable();

	/* Program the power controller to turn the cluster off */
	fvp_pwrc_write_pcoffr(mpidr);
}

/*******************************************************************************
 * FVP handler called when an affinity instance is about to enter standby.
 ******************************************************************************/
void fvp_affinst_standby(unsigned int power_state)
{
	/*
	 * Enter standby state
	 * dsb is good practice before using wfi to enter low power states
	 */
	dsb();
	wfi();
}

/*******************************************************************************
 * FVP handler called when an affinity instance is about to be turned on. The
 * level and mpidr determine the affinity instance.
 ******************************************************************************/
int fvp_affinst_on(unsigned long mpidr,
		   unsigned long sec_entrypoint,
		   unsigned int afflvl,
		   unsigned int state)
{
	int rc = PSCI_E_SUCCESS;
	unsigned int psysr;

	/*
	 * It's possible to turn on only affinity level 0 i.e. a cpu
	 * on the FVP. Ignore any other affinity level.
	 */
	if (afflvl != MPIDR_AFFLVL0)
		return rc;

	/*
	 * Ensure that we do not cancel an inflight power off request
	 * for the target cpu. That would leave it in a zombie wfi.
	 * Wait for it to power off, program the jump address for the
	 * target cpu and then program the power controller to turn
	 * that cpu on
	 */
	do {
		psysr = fvp_pwrc_read_psysr(mpidr);
	} while (psysr & PSYSR_AFF_L0);

	fvp_program_mailbox(mpidr, sec_entrypoint);
	fvp_pwrc_write_pponr(mpidr);

	return rc;
}

/*******************************************************************************
 * FVP handler called when an affinity instance is about to be turned off. The
 * level and mpidr determine the affinity instance. The 'state' arg. allows the
 * platform to decide whether the cluster is being turned off and take apt
 * actions.
 *
 * CAUTION: There is no guarantee that caches will remain turned on across calls
 * to this function as each affinity level is dealt with. So do not write & read
 * global variables across calls. It will be wise to do flush a write to the
 * global to prevent unpredictable results.
 ******************************************************************************/
void fvp_affinst_off(unsigned int afflvl,
		    unsigned int state)
{
	/* Determine if any platform actions need to be executed */
	if (arm_do_affinst_actions(afflvl, state) == -EAGAIN)
		return;

	/*
	 * If execution reaches this stage then this affinity level will be
	 * suspended. Perform at least the cpu specific actions followed the
	 * cluster specific operations if applicable.
	 */
	fvp_cpu_pwrdwn_common();

	if (afflvl != MPIDR_AFFLVL0)
		fvp_cluster_pwrdwn_common();

}

/*******************************************************************************
 * FVP handler called when an affinity instance is about to be suspended. The
 * level and mpidr determine the affinity instance. The 'state' arg. allows the
 * platform to decide whether the cluster is being turned off and take apt
 * actions.
 *
 * CAUTION: There is no guarantee that caches will remain turned on across calls
 * to this function as each affinity level is dealt with. So do not write & read
 * global variables across calls. It will be wise to do flush a write to the
 * global to prevent unpredictable results.
 ******************************************************************************/
void fvp_affinst_suspend(unsigned long sec_entrypoint,
			unsigned int afflvl,
			unsigned int state)
{
	unsigned long mpidr;

	/* Determine if any platform actions need to be executed. */
	if (arm_do_affinst_actions(afflvl, state) == -EAGAIN)
		return;

	/* Get the mpidr for this cpu */
	mpidr = read_mpidr_el1();

	/* Program the jump address for the this cpu */
	fvp_program_mailbox(mpidr, sec_entrypoint);

	/* Program the power controller to enable wakeup interrupts. */
	fvp_pwrc_set_wen(mpidr);

	/* Perform the common cpu specific operations */
	fvp_cpu_pwrdwn_common();

	/* Perform the common cluster specific operations */
	if (afflvl != MPIDR_AFFLVL0)
		fvp_cluster_pwrdwn_common();
}

/*******************************************************************************
 * FVP handler called when an affinity instance has just been powered on after
 * being turned off earlier. The level and mpidr determine the affinity
 * instance. The 'state' arg. allows the platform to decide whether the cluster
 * was turned off prior to wakeup and do what's necessary to setup it up
 * correctly.
 ******************************************************************************/
void fvp_affinst_on_finish(unsigned int afflvl,
			  unsigned int state)
{
	unsigned long mpidr;

	/* Determine if any platform actions need to be executed. */
	if (arm_do_affinst_actions(afflvl, state) == -EAGAIN)
		return;

	/* Get the mpidr for this cpu */
	mpidr = read_mpidr_el1();

	/* Perform the common cluster specific operations */
	if (afflvl != MPIDR_AFFLVL0) {
		/*
		 * This CPU might have woken up whilst the cluster was
		 * attempting to power down. In this case the FVP power
		 * controller will have a pending cluster power off request
		 * which needs to be cleared by writing to the PPONR register.
		 * This prevents the power controller from interpreting a
		 * subsequent entry of this cpu into a simple wfi as a power
		 * down request.
		 */
		fvp_pwrc_write_pponr(mpidr);

		/* Enable coherency if this cluster was off */
		fvp_cci_enable();
	}

	/*
	 * Clear PWKUPR.WEN bit to ensure interrupts do not interfere
	 * with a cpu power down unless the bit is set again
	 */
	fvp_pwrc_clr_wen(mpidr);

	/* Zero the jump address in the mailbox for this cpu */
	fvp_program_mailbox(mpidr, 0);

	/* Enable the gic cpu interface */
	arm_gic_cpuif_setup();

	/* TODO: This setup is needed only after a cold boot */
	arm_gic_pcpu_distif_setup();
}

/*******************************************************************************
 * FVP handler called when an affinity instance has just been powered on after
 * having been suspended earlier. The level and mpidr determine the affinity
 * instance.
 * TODO: At the moment we reuse the on finisher and reinitialize the secure
 * context. Need to implement a separate suspend finisher.
 ******************************************************************************/
void fvp_affinst_suspend_finish(unsigned int afflvl,
			       unsigned int state)
{
	fvp_affinst_on_finish(afflvl, state);
}

/*******************************************************************************
 * FVP handlers to shutdown/reboot the system
 ******************************************************************************/
static void __dead2 fvp_system_off(void)
{
	/* Write the System Configuration Control Register */
	mmio_write_32(V2M_SYSREGS_BASE + V2M_SYS_CFGCTRL,
		V2M_CFGCTRL_START |
		V2M_CFGCTRL_RW |
		V2M_CFGCTRL_FUNC(V2M_FUNC_SHUTDOWN));
	wfi();
	ERROR("FVP System Off: operation not handled.\n");
	panic();
}

static void __dead2 fvp_system_reset(void)
{
	/* Write the System Configuration Control Register */
	mmio_write_32(V2M_SYSREGS_BASE + V2M_SYS_CFGCTRL,
		V2M_CFGCTRL_START |
		V2M_CFGCTRL_RW |
		V2M_CFGCTRL_FUNC(V2M_FUNC_REBOOT));
	wfi();
	ERROR("FVP System Reset: operation not handled.\n");
	panic();
}

/*******************************************************************************
 * Export the platform handlers to enable psci to invoke them
 ******************************************************************************/
static const plat_pm_ops_t fvp_plat_pm_ops = {
	.affinst_standby = fvp_affinst_standby,
	.affinst_on = fvp_affinst_on,
	.affinst_off = fvp_affinst_off,
	.affinst_suspend = fvp_affinst_suspend,
	.affinst_on_finish = fvp_affinst_on_finish,
	.affinst_suspend_finish = fvp_affinst_suspend_finish,
	.system_off = fvp_system_off,
	.system_reset = fvp_system_reset,
	.validate_power_state = arm_validate_power_state
};

/*******************************************************************************
 * Export the platform specific power ops & initialize the fvp power controller
 ******************************************************************************/
int platform_setup_pm(const plat_pm_ops_t **plat_ops)
{
	*plat_ops = &fvp_plat_pm_ops;
	return 0;
}