aboutsummaryrefslogtreecommitdiff
path: root/plat/rpi/rpi3/rpi3_mbox.c
diff options
context:
space:
mode:
Diffstat (limited to 'plat/rpi/rpi3/rpi3_mbox.c')
-rw-r--r--plat/rpi/rpi3/rpi3_mbox.c148
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;
+}