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