blob: 03b395e787ed1e8e920f002df72a3bd6814da706 [file] [log] [blame]
/*
* Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <assert.h>
#include <platform_def.h>
#include <arch_helpers.h>
#include <common/debug.h>
#include <lib/mmio.h>
#include <rpi_hw.h>
/* This struct must be aligned to 16 bytes */
typedef struct __packed __aligned(16) rpi3_mbox_request {
uint32_t size; /* Buffer size in bytes */
uint32_t code; /* Request/response code */
uint32_t tags[0];
} rpi3_mbox_request_t;
#define RPI3_MBOX_BUFFER_SIZE U(256)
static uint8_t __aligned(16) rpi3_mbox_buffer[RPI3_MBOX_BUFFER_SIZE];
/* Constants to perform a request/check the status of a request. */
#define RPI3_MBOX_PROCESS_REQUEST U(0x00000000)
#define RPI3_MBOX_REQUEST_SUCCESSFUL U(0x80000000)
#define RPI3_MBOX_REQUEST_ERROR U(0x80000001)
/* Command constants */
#define RPI3_TAG_HARDWARE_GET_BOARD_REVISION U(0x00010002)
#define RPI3_TAG_END U(0x00000000)
#define RPI3_TAG_REQUEST U(0x00000000)
#define RPI3_TAG_IS_RESPONSE U(0x80000000) /* Set if response */
#define RPI3_TAG_RESPONSE_LENGTH_MASK U(0x7FFFFFFF)
#define RPI3_CHANNEL_ARM_TO_VC U(0x8)
#define RPI3_CHANNEL_MASK U(0xF)
#define RPI3_MAILBOX_MAX_RETRIES U(1000000)
/*******************************************************************************
* Helpers to send requests to the VideoCore using the mailboxes.
******************************************************************************/
static void rpi3_vc_mailbox_request_send(void)
{
uint32_t st, data;
uintptr_t resp_addr, addr;
unsigned int retries;
/* This is the location of the request buffer */
addr = (uintptr_t) &rpi3_mbox_buffer;
/* Make sure that the changes are seen by the VideoCore */
flush_dcache_range(addr, RPI3_MBOX_BUFFER_SIZE);
/* Wait until the outbound mailbox is empty */
retries = 0U;
do {
st = mmio_read_32(RPI3_MBOX_BASE + RPI3_MBOX1_STATUS_OFFSET);
retries++;
if (retries == RPI3_MAILBOX_MAX_RETRIES) {
ERROR("rpi3: mbox: Send request timeout\n");
return;
}
} while ((st & RPI3_MBOX_STATUS_EMPTY_MASK) == 0U);
/* Send base address of this message to start request */
mmio_write_32(RPI3_MBOX_BASE + RPI3_MBOX1_WRITE_OFFSET,
RPI3_CHANNEL_ARM_TO_VC | (uint32_t) addr);
/* Wait until the inbound mailbox isn't empty */
retries = 0U;
do {
st = mmio_read_32(RPI3_MBOX_BASE + RPI3_MBOX0_STATUS_OFFSET);
retries++;
if (retries == RPI3_MAILBOX_MAX_RETRIES) {
ERROR("rpi3: mbox: Receive response timeout\n");
return;
}
} while ((st & RPI3_MBOX_STATUS_EMPTY_MASK) != 0U);
/* Get location and channel */
data = mmio_read_32(RPI3_MBOX_BASE + RPI3_MBOX0_READ_OFFSET);
if ((data & RPI3_CHANNEL_MASK) != RPI3_CHANNEL_ARM_TO_VC) {
ERROR("rpi3: mbox: Wrong channel: 0x%08x\n", data);
panic();
}
resp_addr = (uintptr_t)(data & ~RPI3_CHANNEL_MASK);
if (addr != resp_addr) {
ERROR("rpi3: mbox: Unexpected address: 0x%08x\n", data);
panic();
}
/* Make sure that the data seen by the CPU is up to date */
inv_dcache_range(addr, RPI3_MBOX_BUFFER_SIZE);
}
/*******************************************************************************
* Request board revision. Returns the revision and 0 on success, -1 on error.
******************************************************************************/
int rpi3_vc_hardware_get_board_revision(uint32_t *revision)
{
uint32_t tag_request_size = sizeof(uint32_t);
rpi3_mbox_request_t *req = (rpi3_mbox_request_t *) rpi3_mbox_buffer;
assert(revision != NULL);
VERBOSE("rpi3: mbox: Sending request at %p\n", (void *)req);
req->size = sizeof(rpi3_mbox_buffer);
req->code = RPI3_MBOX_PROCESS_REQUEST;
req->tags[0] = RPI3_TAG_HARDWARE_GET_BOARD_REVISION;
req->tags[1] = tag_request_size; /* Space available for the response */
req->tags[2] = RPI3_TAG_REQUEST;
req->tags[3] = 0; /* Placeholder for the response */
req->tags[4] = RPI3_TAG_END;
rpi3_vc_mailbox_request_send();
if (req->code != RPI3_MBOX_REQUEST_SUCCESSFUL) {
ERROR("rpi3: mbox: Code = 0x%08x\n", req->code);
return -1;
}
if (req->tags[2] != (RPI3_TAG_IS_RESPONSE | tag_request_size)) {
ERROR("rpi3: mbox: get board revision failed (0x%08x)\n",
req->tags[2]);
return -1;
}
*revision = req->tags[3];
return 0;
}