diff options
Diffstat (limited to 'plat/rpi/rpi3/rpi3_mbox.c')
-rw-r--r-- | plat/rpi/rpi3/rpi3_mbox.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/plat/rpi/rpi3/rpi3_mbox.c b/plat/rpi/rpi3/rpi3_mbox.c new file mode 100644 index 0000000000..2db605edf0 --- /dev/null +++ b/plat/rpi/rpi3/rpi3_mbox.c @@ -0,0 +1,148 @@ +/* + * 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 "rpi3_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; +} |