blob: 8482d219c2b9be6b782eb40e3a2cb56a5b8f9201 [file] [log] [blame]
/*
* Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch_helpers.h>
#include <assert.h>
#include <debug.h>
#include "scmi.h"
#include "scmi_private.h"
/*
* Private helper function to get exclusive access to SCMI channel.
*/
void scmi_get_channel(scmi_channel_t *ch)
{
assert(ch->lock);
bakery_lock_get(ch->lock);
/* Make sure any previous command has finished */
assert(SCMI_IS_CHANNEL_FREE(
((mailbox_mem_t *)(ch->info->scmi_mbx_mem))->status));
}
/*
* Private helper function to transfer ownership of channel from AP to SCP.
*/
void scmi_send_sync_command(scmi_channel_t *ch)
{
mailbox_mem_t *mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
SCMI_MARK_CHANNEL_BUSY(mbx_mem->status);
/*
* Ensure that any write to the SCMI payload area is seen by SCP before
* we write to the doorbell register. If these 2 writes were reordered
* by the CPU then SCP would read stale payload data
*/
dmbst();
ch->info->ring_doorbell(ch->info);
/*
* Ensure that the write to the doorbell register is ordered prior to
* checking whether the channel is free.
*/
dmbsy();
/* Wait for channel to be free */
while (!SCMI_IS_CHANNEL_FREE(mbx_mem->status))
;
/*
* Ensure that any read to the SCMI payload area is done after reading
* mailbox status. If these 2 reads were reordered then the CPU would
* read invalid payload data
*/
dmbld();
}
/*
* Private helper function to release exclusive access to SCMI channel.
*/
void scmi_put_channel(scmi_channel_t *ch)
{
/* Make sure any previous command has finished */
assert(SCMI_IS_CHANNEL_FREE(
((mailbox_mem_t *)(ch->info->scmi_mbx_mem))->status));
assert(ch->lock);
bakery_lock_release(ch->lock);
}
/*
* API to query the SCMI protocol version.
*/
int scmi_proto_version(void *p, uint32_t proto_id, uint32_t *version)
{
mailbox_mem_t *mbx_mem;
int token = 0, ret;
scmi_channel_t *ch = (scmi_channel_t *)p;
validate_scmi_channel(ch);
scmi_get_channel(ch);
mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
mbx_mem->msg_header = SCMI_MSG_CREATE(proto_id, SCMI_PROTO_VERSION_MSG,
token);
mbx_mem->len = SCMI_PROTO_VERSION_MSG_LEN;
mbx_mem->flags = SCMI_FLAG_RESP_POLL;
scmi_send_sync_command(ch);
/* Get the return values */
SCMI_PAYLOAD_RET_VAL2(mbx_mem->payload, ret, *version);
assert(mbx_mem->len == SCMI_PROTO_VERSION_RESP_LEN);
assert(token == SCMI_MSG_GET_TOKEN(mbx_mem->msg_header));
scmi_put_channel(ch);
return ret;
}
/*
* API to query the protocol message attributes for a SCMI protocol.
*/
int scmi_proto_msg_attr(void *p, uint32_t proto_id,
uint32_t command_id, uint32_t *attr)
{
mailbox_mem_t *mbx_mem;
int token = 0, ret;
scmi_channel_t *ch = (scmi_channel_t *)p;
validate_scmi_channel(ch);
scmi_get_channel(ch);
mbx_mem = (mailbox_mem_t *)(ch->info->scmi_mbx_mem);
mbx_mem->msg_header = SCMI_MSG_CREATE(proto_id,
SCMI_PROTO_MSG_ATTR_MSG, token);
mbx_mem->len = SCMI_PROTO_MSG_ATTR_MSG_LEN;
mbx_mem->flags = SCMI_FLAG_RESP_POLL;
SCMI_PAYLOAD_ARG1(mbx_mem->payload, command_id);
scmi_send_sync_command(ch);
/* Get the return values */
SCMI_PAYLOAD_RET_VAL2(mbx_mem->payload, ret, *attr);
assert(mbx_mem->len == SCMI_PROTO_MSG_ATTR_RESP_LEN);
assert(token == SCMI_MSG_GET_TOKEN(mbx_mem->msg_header));
scmi_put_channel(ch);
return ret;
}
/*
* SCMI Driver initialization API. Returns initialized channel on success
* or NULL on error. The return type is an opaque void pointer.
*/
void *scmi_init(scmi_channel_t *ch)
{
uint32_t version;
int ret;
assert(ch && ch->info);
assert(ch->info->db_reg_addr);
assert(ch->info->db_modify_mask);
assert(ch->info->db_preserve_mask);
assert(ch->info->ring_doorbell != NULL);
assert(ch->lock);
bakery_lock_init(ch->lock);
ch->is_initialized = 1;
ret = scmi_proto_version(ch, SCMI_PWR_DMN_PROTO_ID, &version);
if (ret != SCMI_E_SUCCESS) {
WARN("SCMI power domain protocol version message failed");
goto error;
}
if (!is_scmi_version_compatible(SCMI_PWR_DMN_PROTO_VER, version)) {
WARN("SCMI power domain protocol version 0x%x incompatible with driver version 0x%x",
version, SCMI_PWR_DMN_PROTO_VER);
goto error;
}
VERBOSE("SCMI power domain protocol version 0x%x detected\n", version);
ret = scmi_proto_version(ch, SCMI_SYS_PWR_PROTO_ID, &version);
if ((ret != SCMI_E_SUCCESS)) {
WARN("SCMI system power protocol version message failed");
goto error;
}
if (!is_scmi_version_compatible(SCMI_SYS_PWR_PROTO_VER, version)) {
WARN("SCMI system power management protocol version 0x%x incompatible with driver version 0x%x",
version, SCMI_SYS_PWR_PROTO_VER);
goto error;
}
VERBOSE("SCMI system power management protocol version 0x%x detected\n",
version);
INFO("SCMI driver initialized\n");
return (void *)ch;
error:
ch->is_initialized = 0;
return NULL;
}