arch/arm/mach-bcm283x/mbox.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2012 Stephen Warren
   4  */
   5
   6 #include <common.h>
   7 #include <cpu_func.h>
   8 #include <asm/io.h>
   9 #include <asm/arch/base.h>
  10 #include <asm/arch/mbox.h>
  11 #include <phys2bus.h>
  12
  13 #define TIMEOUT 1000 /* ms */
  14
  15 int bcm2835_mbox_call_raw(u32 chan, u32 send, u32 *recv)
  16 {
  17         struct bcm2835_mbox_regs *regs =
  18                 (struct bcm2835_mbox_regs *)BCM2835_MBOX_PHYSADDR;
  19         ulong endtime = get_timer(0) + TIMEOUT;
  20         u32 val;
  21
  22         debug("time: %lu timeout: %lu\n", get_timer(0), endtime);
  23
  24         if (send & BCM2835_CHAN_MASK) {
  25                 printf("mbox: Illegal mbox data 0x%08x\n", send);
  26                 return -1;
  27         }
  28
  29         /* Drain any stale responses */
  30
  31         for (;;) {
  32                 val = readl(&regs->mail0_status);
  33                 if (val & BCM2835_MBOX_STATUS_RD_EMPTY)
  34                         break;
  35                 if (get_timer(0) >= endtime) {
  36                         printf("mbox: Timeout draining stale responses\n");
  37                         return -1;
  38                 }
  39                 val = readl(&regs->read);
  40         }
  41
  42         /* Wait for space to send */
  43
  44         for (;;) {
  45                 val = readl(&regs->mail1_status);
  46                 if (!(val & BCM2835_MBOX_STATUS_WR_FULL))
  47                         break;
  48                 if (get_timer(0) >= endtime) {
  49                         printf("mbox: Timeout waiting for send space\n");
  50                         return -1;
  51                 }
  52         }
  53
  54         /* Send the request */
  55
  56         val = BCM2835_MBOX_PACK(chan, send);
  57         debug("mbox: TX raw: 0x%08x\n", val);
  58         writel(val, &regs->write);
  59
  60         /* Wait for the response */
  61
  62         for (;;) {
  63                 val = readl(&regs->mail0_status);
  64                 if (!(val & BCM2835_MBOX_STATUS_RD_EMPTY))
  65                         break;
  66                 if (get_timer(0) >= endtime) {
  67                         printf("mbox: Timeout waiting for response\n");
  68                         return -1;
  69                 }
  70         }
  71
  72         /* Read the response */
  73
  74         val = readl(&regs->read);
  75         debug("mbox: RX raw: 0x%08x\n", val);
  76
  77         /* Validate the response */
  78
  79         if (BCM2835_MBOX_UNPACK_CHAN(val) != chan) {
  80                 printf("mbox: Response channel mismatch\n");
  81                 return -1;
  82         }
  83
  84         *recv = BCM2835_MBOX_UNPACK_DATA(val);
  85
  86         return 0;
  87 }
  88
  89 #ifdef DEBUG
  90 void dump_buf(struct bcm2835_mbox_hdr *buffer)
  91 {
  92         u32 *p;
  93         u32 words;
  94         int i;
  95
  96         p = (u32 *)buffer;
  97         words = buffer->buf_size / 4;
  98         for (i = 0; i < words; i++)
  99                 printf("    0x%04x: 0x%08x\n", i * 4, p[i]);
 100 }
 101 #endif
 102
 103 int bcm2835_mbox_call_prop(u32 chan, struct bcm2835_mbox_hdr *buffer)
 104 {
 105         int ret;
 106         u32 rbuffer;
 107         struct bcm2835_mbox_tag_hdr *tag;
 108         int tag_index;
 109
 110 #ifdef DEBUG
 111         printf("mbox: TX buffer\n");
 112         dump_buf(buffer);
 113 #endif
 114
 115         flush_dcache_range((unsigned long)buffer,
 116                            (unsigned long)((void *)buffer +
 117                            roundup(buffer->buf_size, ARCH_DMA_MINALIGN)));
 118
 119         ret = bcm2835_mbox_call_raw(chan,
 120                                     phys_to_bus((unsigned long)buffer),
 121                                     &rbuffer);
 122         if (ret)
 123                 return ret;
 124
 125         invalidate_dcache_range((unsigned long)buffer,
 126                                 (unsigned long)((void *)buffer +
 127                                 roundup(buffer->buf_size, ARCH_DMA_MINALIGN)));
 128
 129         if (rbuffer != phys_to_bus((unsigned long)buffer)) {
 130                 printf("mbox: Response buffer mismatch\n");
 131                 return -1;
 132         }
 133
 134 #ifdef DEBUG
 135         printf("mbox: RX buffer\n");
 136         dump_buf(buffer);
 137 #endif
 138
 139         /* Validate overall response status */
 140
 141         if (buffer->code != BCM2835_MBOX_RESP_CODE_SUCCESS) {
 142                 printf("mbox: Header response code invalid\n");
 143                 return -1;
 144         }
 145
 146         /* Validate each tag's response status */
 147
 148         tag = (void *)(buffer + 1);
 149         tag_index = 0;
 150         while (tag->tag) {
 151                 if (!(tag->val_len & BCM2835_MBOX_TAG_VAL_LEN_RESPONSE)) {
 152                         printf("mbox: Tag %d missing val_len response bit\n",
 153                                 tag_index);
 154                         return -1;
 155                 }
 156                 /*
 157                  * Clear the reponse bit so clients can just look right at the
 158                  * length field without extra processing
 159                  */
 160                 tag->val_len &= ~BCM2835_MBOX_TAG_VAL_LEN_RESPONSE;
 161                 tag = (void *)(((u8 *)tag) + sizeof(*tag) + tag->val_buf_size);
 162                 tag_index++;
 163         }
 164
 165         return 0;
 166 }