drivers/mailbox/sandbox-mbox.c

   1 /*
   2  * Copyright (c) 2016, NVIDIA CORPORATION.
   3  *
   4  * SPDX-License-Identifier: GPL-2.0
   5  */
   6
   7 #include <common.h>
   8 #include <dm.h>
   9 #include <mailbox-uclass.h>
  10 #include <asm/io.h>
  11 #include <asm/mbox.h>
  12
  13 #define SANDBOX_MBOX_CHANNELS 2
  14
  15 struct sandbox_mbox_chan {
  16         bool rx_msg_valid;
  17         uint32_t rx_msg;
  18 };
  19
  20 struct sandbox_mbox {
  21         struct sandbox_mbox_chan chans[SANDBOX_MBOX_CHANNELS];
  22 };
  23
  24 static int sandbox_mbox_request(struct mbox_chan *chan)
  25 {
  26         debug("%s(chan=%p)\n", __func__, chan);
  27
  28         if (chan->id >= SANDBOX_MBOX_CHANNELS)
  29                 return -EINVAL;
  30
  31         return 0;
  32 }
  33
  34 static int sandbox_mbox_free(struct mbox_chan *chan)
  35 {
  36         debug("%s(chan=%p)\n", __func__, chan);
  37
  38         return 0;
  39 }
  40
  41 static int sandbox_mbox_send(struct mbox_chan *chan, const void *data)
  42 {
  43         struct sandbox_mbox *sbm = dev_get_priv(chan->dev);
  44         const uint32_t *pmsg = data;
  45
  46         debug("%s(chan=%p, data=%p)\n", __func__, chan, data);
  47
  48         sbm->chans[chan->id].rx_msg = *pmsg ^ SANDBOX_MBOX_PING_XOR;
  49         sbm->chans[chan->id].rx_msg_valid = true;
  50
  51         return 0;
  52 }
  53
  54 static int sandbox_mbox_recv(struct mbox_chan *chan, void *data)
  55 {
  56         struct sandbox_mbox *sbm = dev_get_priv(chan->dev);
  57         uint32_t *pmsg = data;
  58
  59         debug("%s(chan=%p, data=%p)\n", __func__, chan, data);
  60
  61         if (!sbm->chans[chan->id].rx_msg_valid)
  62                 return -ENODATA;
  63
  64         *pmsg = sbm->chans[chan->id].rx_msg;
  65         sbm->chans[chan->id].rx_msg_valid = false;
  66
  67         return 0;
  68 }
  69
  70 static int sandbox_mbox_bind(struct udevice *dev)
  71 {
  72         debug("%s(dev=%p)\n", __func__, dev);
  73
  74         return 0;
  75 }
  76
  77 static int sandbox_mbox_probe(struct udevice *dev)
  78 {
  79         debug("%s(dev=%p)\n", __func__, dev);
  80
  81         return 0;
  82 }
  83
  84 static const struct udevice_id sandbox_mbox_ids[] = {
  85         { .compatible = "sandbox,mbox" },
  86         { }
  87 };
  88
  89 struct mbox_ops sandbox_mbox_mbox_ops = {
  90         .request = sandbox_mbox_request,
  91         .free = sandbox_mbox_free,
  92         .send = sandbox_mbox_send,
  93         .recv = sandbox_mbox_recv,
  94 };
  95
  96 U_BOOT_DRIVER(sandbox_mbox) = {
  97         .name = "sandbox_mbox",
  98         .id = UCLASS_MAILBOX,
  99         .of_match = sandbox_mbox_ids,
 100         .bind = sandbox_mbox_bind,
 101         .probe = sandbox_mbox_probe,
 102         .priv_auto_alloc_size = sizeof(struct sandbox_mbox),
 103         .ops = &sandbox_mbox_mbox_ops,
 104 };