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      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 
     44 void *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 
     52 void 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 
     61 unsigned 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 
     84 void scpi_secure_message_end(void)
     85 {
     86 	mhu_secure_message_end();
     87 }
     88 
     89 static 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 
     96 int 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 
    117 void 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 
    128 uint32_t scpi_sys_power_state(scpi_system_state_t system_state)
    129 {
    130 	uint32_t *response;
    131 	size_t size;
    132 	uint8_t state = system_state & 0xff;
    133 
    134 	/* Send the command */
    135 	*(__typeof__(state) *)scpi_secure_message_start() = state;
    136 	scpi_secure_message_send(SCPI_CMD_SYS_POWER_STATE, sizeof(state));
    137 	scpi_secure_message_receive((void *)&response, &size);
    138 	scpi_secure_message_end();
    139 	return *response;
    140 }
    141