1 /* 2 * (C) Copyright 2012 Stephen Warren 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <asm/io.h> 9 #include <asm/arch/mbox.h> 10 11 #define TIMEOUT 1000 /* ms */ 12 13 int bcm2835_mbox_call_raw(u32 chan, u32 send, u32 *recv) 14 { 15 struct bcm2835_mbox_regs *regs = 16 (struct bcm2835_mbox_regs *)BCM2835_MBOX_PHYSADDR; 17 ulong endtime = get_timer(0) + TIMEOUT; 18 u32 val; 19 20 debug("time: %lu timeout: %lu\n", get_timer(0), endtime); 21 22 if (send & BCM2835_CHAN_MASK) { 23 printf("mbox: Illegal mbox data 0x%08x\n", send); 24 return -1; 25 } 26 27 /* Drain any stale responses */ 28 29 for (;;) { 30 val = readl(®s->status); 31 if (val & BCM2835_MBOX_STATUS_RD_EMPTY) 32 break; 33 if (get_timer(0) >= endtime) { 34 printf("mbox: Timeout draining stale responses\n"); 35 return -1; 36 } 37 val = readl(®s->read); 38 } 39 40 /* Wait for space to send */ 41 42 for (;;) { 43 val = readl(®s->status); 44 if (!(val & BCM2835_MBOX_STATUS_WR_FULL)) 45 break; 46 if (get_timer(0) >= endtime) { 47 printf("mbox: Timeout waiting for send space\n"); 48 return -1; 49 } 50 } 51 52 /* Send the request */ 53 54 val = BCM2835_MBOX_PACK(chan, send); 55 debug("mbox: TX raw: 0x%08x\n", val); 56 writel(val, ®s->write); 57 58 /* Wait for the response */ 59 60 for (;;) { 61 val = readl(®s->status); 62 if (!(val & BCM2835_MBOX_STATUS_RD_EMPTY)) 63 break; 64 if (get_timer(0) >= endtime) { 65 printf("mbox: Timeout waiting for response\n"); 66 return -1; 67 } 68 } 69 70 /* Read the response */ 71 72 val = readl(®s->read); 73 debug("mbox: RX raw: 0x%08x\n", val); 74 75 /* Validate the response */ 76 77 if (BCM2835_MBOX_UNPACK_CHAN(val) != chan) { 78 printf("mbox: Response channel mismatch\n"); 79 return -1; 80 } 81 82 *recv = BCM2835_MBOX_UNPACK_DATA(val); 83 84 return 0; 85 } 86 87 #ifdef DEBUG 88 void dump_buf(struct bcm2835_mbox_hdr *buffer) 89 { 90 u32 *p; 91 u32 words; 92 int i; 93 94 p = (u32 *)buffer; 95 words = buffer->buf_size / 4; 96 for (i = 0; i < words; i++) 97 printf(" 0x%04x: 0x%08x\n", i * 4, p[i]); 98 } 99 #endif 100 101 int bcm2835_mbox_call_prop(u32 chan, struct bcm2835_mbox_hdr *buffer) 102 { 103 int ret; 104 u32 rbuffer; 105 struct bcm2835_mbox_tag_hdr *tag; 106 int tag_index; 107 108 #ifdef DEBUG 109 printf("mbox: TX buffer\n"); 110 dump_buf(buffer); 111 #endif 112 113 ret = bcm2835_mbox_call_raw(chan, (u32)buffer, &rbuffer); 114 if (ret) 115 return ret; 116 if (rbuffer != (u32)buffer) { 117 printf("mbox: Response buffer mismatch\n"); 118 return -1; 119 } 120 121 #ifdef DEBUG 122 printf("mbox: RX buffer\n"); 123 dump_buf(buffer); 124 #endif 125 126 /* Validate overall response status */ 127 128 if (buffer->code != BCM2835_MBOX_RESP_CODE_SUCCESS) { 129 printf("mbox: Header response code invalid\n"); 130 return -1; 131 } 132 133 /* Validate each tag's response status */ 134 135 tag = (void *)(buffer + 1); 136 tag_index = 0; 137 while (tag->tag) { 138 if (!(tag->val_len & BCM2835_MBOX_TAG_VAL_LEN_RESPONSE)) { 139 printf("mbox: Tag %d missing val_len response bit\n", 140 tag_index); 141 return -1; 142 } 143 /* 144 * Clear the reponse bit so clients can just look right at the 145 * length field without extra processing 146 */ 147 tag->val_len &= ~BCM2835_MBOX_TAG_VAL_LEN_RESPONSE; 148 tag = (void *)(((u8 *)tag) + sizeof(*tag) + tag->val_buf_size); 149 tag_index++; 150 } 151 152 return 0; 153 } 154