scpi.c revision 01b916bff2dca219d4088b8abca0a02ac06dd615 
1/*
2 * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * Neither the name of ARM nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without specific
16 * prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <arch_helpers.h>
32#include <platform.h>
33#include "juno_def.h"
34#include "mhu.h"
35#include "scpi.h"
36
37#define MHU_SECURE_SCP_TO_AP_PAYLOAD	(MHU_SECURE_BASE+0x0080)
38#define MHU_SECURE_AP_TO_SCP_PAYLOAD	(MHU_SECURE_BASE+0x0280)
39
40#define SIZE_SHIFT	20	/* Bit position for size value in MHU header */
41#define SIZE_MASK	0x1ff	/* Mask to extract size value in MHU header*/
42
43
44void *scpi_secure_message_start(void)
45{
46	mhu_secure_message_start();
47
48	/* Return address of payload area. */
49	return (void *)MHU_SECURE_AP_TO_SCP_PAYLOAD;
50}
51
52void scpi_secure_message_send(unsigned command, size_t size)
53{
54	/* Make sure payload can be seen by SCP */
55	if (MHU_PAYLOAD_CACHED)
56		flush_dcache_range(MHU_SECURE_AP_TO_SCP_PAYLOAD, size);
57
58	mhu_secure_message_send(command | (size << SIZE_SHIFT));
59}
60
61unsigned scpi_secure_message_receive(void **message_out, size_t *size_out)
62{
63	uint32_t response =  mhu_secure_message_wait();
64
65	/* Get size of payload */
66	size_t size = (response >> SIZE_SHIFT) & SIZE_MASK;
67
68	/* Clear size from response */
69	response &= ~(SIZE_MASK << SIZE_SHIFT);
70
71	/* Make sure we don't read stale data */
72	if (MHU_PAYLOAD_CACHED)
73		inv_dcache_range(MHU_SECURE_SCP_TO_AP_PAYLOAD, size);
74
75	if (size_out)
76		*size_out = size;
77
78	if (message_out)
79		*message_out = (void *)MHU_SECURE_SCP_TO_AP_PAYLOAD;
80
81	return response;
82}
83
84void scpi_secure_message_end(void)
85{
86	mhu_secure_message_end();
87}
88
89static void scpi_secure_send32(unsigned command, uint32_t message)
90{
91	*(__typeof__(message) *)scpi_secure_message_start() = message;
92	scpi_secure_message_send(command, sizeof(message));
93	scpi_secure_message_end();
94}
95
96int scpi_wait_ready(void)
97{
98	/* Get a message from the SCP */
99	scpi_secure_message_start();
100	size_t size;
101	unsigned command = scpi_secure_message_receive(NULL, &size);
102	scpi_secure_message_end();
103
104	/* We are expecting 'SCP Ready', produce correct error if it's not */
105	scpi_status_t response = SCP_OK;
106	if (command != SCPI_CMD_SCP_READY)
107		response = SCP_E_SUPPORT;
108	else if (size != 0)
109		response = SCP_E_SIZE;
110
111	/* Send our response back to SCP */
112	scpi_secure_send32(command, response);
113
114	return response == SCP_OK ? 0 : -1;
115}
116
117void scpi_set_css_power_state(unsigned mpidr, scpi_power_state_t cpu_state,
118		scpi_power_state_t cluster_state, scpi_power_state_t css_state)
119{
120	uint32_t state = mpidr & 0x0f;	/* CPU ID */
121	state |= (mpidr & 0xf00) >> 4;	/* Cluster ID */
122	state |= cpu_state << 8;
123	state |= cluster_state << 12;
124	state |= css_state << 16;
125	scpi_secure_send32(SCPI_CMD_SET_CSS_POWER_STATE, state);
126}
127