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/*
* Copyright (c) 2014-2016, 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 <css_def.h>
#include <debug.h>
#include <platform.h>
#include <string.h>
#include "css_mhu.h"
#include "css_scpi.h"
#define SCPI_SHARED_MEM_SCP_TO_AP PLAT_CSS_SCP_COM_SHARED_MEM_BASE
#define SCPI_SHARED_MEM_AP_TO_SCP (PLAT_CSS_SCP_COM_SHARED_MEM_BASE \
+ 0x100)
#define SCPI_CMD_HEADER_AP_TO_SCP \
((scpi_cmd_t *) SCPI_SHARED_MEM_AP_TO_SCP)
#define SCPI_CMD_PAYLOAD_AP_TO_SCP \
((void *) (SCPI_SHARED_MEM_AP_TO_SCP + sizeof(scpi_cmd_t)))
/* ID of the MHU slot used for the SCPI protocol */
#define SCPI_MHU_SLOT_ID 0
static void scpi_secure_message_start(void)
{
mhu_secure_message_start(SCPI_MHU_SLOT_ID);
}
static void scpi_secure_message_send(size_t payload_size)
{
/* Ensure that any write to the SCPI payload area is seen by SCP before
* we write to the MHU register. If these 2 writes were reordered by
* the CPU then SCP would read stale payload data */
dmbst();
mhu_secure_message_send(SCPI_MHU_SLOT_ID);
}
static void scpi_secure_message_receive(scpi_cmd_t *cmd)
{
uint32_t mhu_status;
assert(cmd != NULL);
mhu_status = mhu_secure_message_wait();
/* Expect an SCPI message, reject any other protocol */
if (mhu_status != (1 << SCPI_MHU_SLOT_ID)) {
ERROR("MHU: Unexpected protocol (MHU status: 0x%x)\n",
mhu_status);
panic();
}
/* Ensure that any read to the SCPI payload area is done after reading
* the MHU register. If these 2 reads were reordered then the CPU would
* read invalid payload data */
dmbld();
memcpy(cmd, (void *) SCPI_SHARED_MEM_SCP_TO_AP, sizeof(*cmd));
}
static void scpi_secure_message_end(void)
{
mhu_secure_message_end(SCPI_MHU_SLOT_ID);
}
int scpi_wait_ready(void)
{
scpi_cmd_t scpi_cmd;
VERBOSE("Waiting for SCP_READY command...\n");
/* Get a message from the SCP */
scpi_secure_message_start();
scpi_secure_message_receive(&scpi_cmd);
scpi_secure_message_end();
/* We are expecting 'SCP Ready', produce correct error if it's not */
scpi_status_t status = SCP_OK;
if (scpi_cmd.id != SCPI_CMD_SCP_READY) {
ERROR("Unexpected SCP command: expected command #%u, got command #%u\n",
SCPI_CMD_SCP_READY, scpi_cmd.id);
status = SCP_E_SUPPORT;
} else if (scpi_cmd.size != 0) {
ERROR("SCP_READY command has incorrect size: expected 0, got %u\n",
scpi_cmd.size);
status = SCP_E_SIZE;
}
VERBOSE("Sending response for SCP_READY command\n");
/*
* Send our response back to SCP.
* We are using the same SCPI header, just update the status field.
*/
scpi_cmd.status = status;
scpi_secure_message_start();
memcpy((void *) SCPI_SHARED_MEM_AP_TO_SCP, &scpi_cmd, sizeof(scpi_cmd));
scpi_secure_message_send(0);
scpi_secure_message_end();
return status == SCP_OK ? 0 : -1;
}
void scpi_set_css_power_state(unsigned mpidr, scpi_power_state_t cpu_state,
scpi_power_state_t cluster_state, scpi_power_state_t css_state)
{
scpi_cmd_t *cmd;
uint32_t state = 0;
uint32_t *payload_addr;
state |= mpidr & 0x0f; /* CPU ID */
state |= (mpidr & 0xf00) >> 4; /* Cluster ID */
state |= cpu_state << 8;
state |= cluster_state << 12;
state |= css_state << 16;
scpi_secure_message_start();
/* Populate the command header */
cmd = SCPI_CMD_HEADER_AP_TO_SCP;
cmd->id = SCPI_CMD_SET_CSS_POWER_STATE;
cmd->set = SCPI_SET_NORMAL;
cmd->sender = 0;
cmd->size = sizeof(state);
/* Populate the command payload */
payload_addr = SCPI_CMD_PAYLOAD_AP_TO_SCP;
*payload_addr = state;
scpi_secure_message_send(sizeof(state));
/*
* SCP does not reply to this command in order to avoid MHU interrupts
* from the sender, which could interfere with its power state request.
*/
scpi_secure_message_end();
}
uint32_t scpi_sys_power_state(scpi_system_state_t system_state)
{
scpi_cmd_t *cmd;
uint8_t *payload_addr;
scpi_cmd_t response;
scpi_secure_message_start();
/* Populate the command header */
cmd = SCPI_CMD_HEADER_AP_TO_SCP;
cmd->id = SCPI_CMD_SYS_POWER_STATE;
cmd->set = 0;
cmd->sender = 0;
cmd->size = sizeof(*payload_addr);
/* Populate the command payload */
payload_addr = SCPI_CMD_PAYLOAD_AP_TO_SCP;
*payload_addr = system_state & 0xff;
scpi_secure_message_send(sizeof(*payload_addr));
scpi_secure_message_receive(&response);
scpi_secure_message_end();
return response.status;
}