1 /*
2 * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <platform_def.h>
8
9 #include <arch_helpers.h>
10 #include <common/debug.h>
11 #include <lib/mmio.h>
12
13 #include <rpi_hw.h>
14
15 #include <drivers/rpi3/mailbox/rpi3_mbox.h>
16
17 #define RPI3_MAILBOX_MAX_RETRIES U(1000000)
18
19 /*******************************************************************************
20 * Routine to send requests to the VideoCore using the mailboxes.
21 ******************************************************************************/
rpi3_vc_mailbox_request_send(rpi3_mbox_request_t * req,int req_size)22 void rpi3_vc_mailbox_request_send(rpi3_mbox_request_t *req, int req_size)
23 {
24 uint32_t st, data;
25 uintptr_t resp_addr, addr;
26 unsigned int retries;
27
28 /* This is the location of the request buffer */
29 addr = (uintptr_t)req;
30
31 /* Make sure that the changes are seen by the VideoCore */
32 flush_dcache_range(addr, req_size);
33
34 /* Wait until the outbound mailbox is empty */
35 retries = 0U;
36
37 do {
38 st = mmio_read_32(RPI3_MBOX_BASE + RPI3_MBOX1_STATUS_OFFSET);
39
40 retries++;
41 if (retries == RPI3_MAILBOX_MAX_RETRIES) {
42 ERROR("rpi3: mbox: Send request timeout\n");
43 return;
44 }
45
46 } while ((st & RPI3_MBOX_STATUS_EMPTY_MASK) == 0U);
47
48 /* Send base address of this message to start request */
49 mmio_write_32(RPI3_MBOX_BASE + RPI3_MBOX1_WRITE_OFFSET,
50 RPI3_CHANNEL_ARM_TO_VC | (uint32_t) addr);
51
52 /* Wait until the inbound mailbox isn't empty */
53 retries = 0U;
54
55 do {
56 st = mmio_read_32(RPI3_MBOX_BASE + RPI3_MBOX0_STATUS_OFFSET);
57
58 retries++;
59 if (retries == RPI3_MAILBOX_MAX_RETRIES) {
60 ERROR("rpi3: mbox: Receive response timeout\n");
61 return;
62 }
63
64 } while ((st & RPI3_MBOX_STATUS_EMPTY_MASK) != 0U);
65
66 /* Get location and channel */
67 data = mmio_read_32(RPI3_MBOX_BASE + RPI3_MBOX0_READ_OFFSET);
68
69 if ((data & RPI3_CHANNEL_MASK) != RPI3_CHANNEL_ARM_TO_VC) {
70 ERROR("rpi3: mbox: Wrong channel: 0x%08x\n", data);
71 panic();
72 }
73
74 resp_addr = (uintptr_t)(data & ~RPI3_CHANNEL_MASK);
75 if (addr != resp_addr) {
76 ERROR("rpi3: mbox: Unexpected address: 0x%08x\n", data);
77 panic();
78 }
79
80 /* Make sure that the data seen by the CPU is up to date */
81 inv_dcache_range(addr, req_size);
82 }
83