--- /dev/null
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <assert.h>
+#include <platform_def.h>
+#include <sq_common.h>
+#include <debug.h>
+#include <string.h>
+#include "sq_mhu.h"
+#include "sq_scpi.h"
+
+#define SCPI_SHARED_MEM_SCP_TO_AP PLAT_SQ_SCP_COM_SHARED_MEM_BASE
+#define SCPI_SHARED_MEM_AP_TO_SCP (PLAT_SQ_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;
+ scpi_status_t status = SCP_OK;
+
+ 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 */
+ 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_sq_power_state(unsigned int mpidr, scpi_power_state_t cpu_state,
+ scpi_power_state_t cluster_state, scpi_power_state_t sq_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 |= sq_state << 16;
+
+ scpi_secure_message_start();
+
+ /* Populate the command header */
+ cmd = SCPI_CMD_HEADER_AP_TO_SCP;
+ cmd->id = SCPI_CMD_SET_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;
+}
--- /dev/null
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __SQ_SCPI_H__
+#define __SQ_SCPI_H__
+
+#include <stddef.h>
+#include <stdint.h>
+
+/*
+ * An SCPI command consists of a header and a payload.
+ * The following structure describes the header. It is 64-bit long.
+ */
+typedef struct {
+ /* Command ID */
+ uint32_t id : 7;
+ /* Set ID. Identifies whether this is a standard or extended command. */
+ uint32_t set : 1;
+ /* Sender ID to match a reply. The value is sender specific. */
+ uint32_t sender : 8;
+ /* Size of the payload in bytes (0 - 511) */
+ uint32_t size : 9;
+ uint32_t reserved : 7;
+ /*
+ * Status indicating the success of a command.
+ * See the enum below.
+ */
+ uint32_t status;
+} scpi_cmd_t;
+
+typedef enum {
+ SCPI_SET_NORMAL = 0, /* Normal SCPI commands */
+ SCPI_SET_EXTENDED /* Extended SCPI commands */
+} scpi_set_t;
+
+enum {
+ SCP_OK = 0, /* Success */
+ SCP_E_PARAM, /* Invalid parameter(s) */
+ SCP_E_ALIGN, /* Invalid alignment */
+ SCP_E_SIZE, /* Invalid size */
+ SCP_E_HANDLER, /* Invalid handler or callback */
+ SCP_E_ACCESS, /* Invalid access or permission denied */
+ SCP_E_RANGE, /* Value out of range */
+ SCP_E_TIMEOUT, /* Time out has ocurred */
+ SCP_E_NOMEM, /* Invalid memory area or pointer */
+ SCP_E_PWRSTATE, /* Invalid power state */
+ SCP_E_SUPPORT, /* Feature not supported or disabled */
+ SCPI_E_DEVICE, /* Device error */
+ SCPI_E_BUSY, /* Device is busy */
+};
+
+typedef uint32_t scpi_status_t;
+
+typedef enum {
+ SCPI_CMD_SCP_READY = 0x01,
+ SCPI_CMD_SET_POWER_STATE = 0x03,
+ SCPI_CMD_SYS_POWER_STATE = 0x05
+} scpi_command_t;
+
+typedef enum {
+ scpi_power_on = 0,
+ scpi_power_retention = 1,
+ scpi_power_off = 3,
+} scpi_power_state_t;
+
+typedef enum {
+ scpi_system_shutdown = 0,
+ scpi_system_reboot = 1,
+ scpi_system_reset = 2
+} scpi_system_state_t;
+
+extern int scpi_wait_ready(void);
+extern void scpi_set_sq_power_state(unsigned int mpidr,
+ scpi_power_state_t cpu_state,
+ scpi_power_state_t cluster_state,
+ scpi_power_state_t css_state);
+uint32_t scpi_sys_power_state(scpi_system_state_t system_state);
+
+#endif /* __SQ_SCPI_H__ */