git.sur5r.net Git - u-boot/blob - arch/arm/mach-bcm283x/mbox.c

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