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 ******************************************************************************/ 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