1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2020 Linaro Limited.
4 */
5
6 #include <common.h>
7 #include <dm.h>
8 #include <dm/device_compat.h>
9 #include <errno.h>
10 #include <mailbox.h>
11 #include <scmi_agent.h>
12 #include <scmi_agent-uclass.h>
13 #include <dm/devres.h>
14 #include <linux/compat.h>
15
16 #include "smt.h"
17
18 #define TIMEOUT_US_10MS 10000
19
20 /**
21 * struct scmi_mbox_channel - Description of an SCMI mailbox transport
22 * @smt: Shared memory buffer
23 * @mbox: Mailbox channel description
24 * @timeout_us: Timeout in microseconds for the mailbox transfer
25 */
26 struct scmi_mbox_channel {
27 struct scmi_smt smt;
28 struct mbox_chan mbox;
29 ulong timeout_us;
30 };
31
scmi_mbox_process_msg(struct udevice * dev,struct scmi_msg * msg)32 static int scmi_mbox_process_msg(struct udevice *dev, struct scmi_msg *msg)
33 {
34 struct scmi_mbox_channel *chan = dev_get_priv(dev);
35 int ret;
36
37 ret = scmi_write_msg_to_smt(dev, &chan->smt, msg);
38 if (ret)
39 return ret;
40
41 /* Give shm addr to mbox in case it is meaningful */
42 ret = mbox_send(&chan->mbox, chan->smt.buf);
43 if (ret) {
44 dev_err(dev, "Message send failed: %d\n", ret);
45 goto out;
46 }
47
48 /* Receive the response */
49 ret = mbox_recv(&chan->mbox, chan->smt.buf, chan->timeout_us);
50 if (ret) {
51 dev_err(dev, "Response failed: %d, abort\n", ret);
52 goto out;
53 }
54
55 ret = scmi_read_resp_from_smt(dev, &chan->smt, msg);
56
57 out:
58 scmi_clear_smt_channel(&chan->smt);
59
60 return ret;
61 }
62
scmi_mbox_probe(struct udevice * dev)63 int scmi_mbox_probe(struct udevice *dev)
64 {
65 struct scmi_mbox_channel *chan = dev_get_priv(dev);
66 int ret;
67
68 chan->timeout_us = TIMEOUT_US_10MS;
69
70 ret = mbox_get_by_index(dev, 0, &chan->mbox);
71 if (ret) {
72 dev_err(dev, "Failed to find mailbox: %d\n", ret);
73 goto out;
74 }
75
76 ret = scmi_dt_get_smt_buffer(dev, &chan->smt);
77 if (ret)
78 dev_err(dev, "Failed to get shm resources: %d\n", ret);
79
80 out:
81 if (ret)
82 devm_kfree(dev, chan);
83
84 return ret;
85 }
86
87 static const struct udevice_id scmi_mbox_ids[] = {
88 { .compatible = "arm,scmi" },
89 { }
90 };
91
92 static const struct scmi_agent_ops scmi_mbox_ops = {
93 .process_msg = scmi_mbox_process_msg,
94 };
95
96 U_BOOT_DRIVER(scmi_mbox) = {
97 .name = "scmi-over-mailbox",
98 .id = UCLASS_SCMI_AGENT,
99 .of_match = scmi_mbox_ids,
100 .priv_auto_alloc_size = sizeof(struct scmi_mbox_channel),
101 .probe = scmi_mbox_probe,
102 .ops = &scmi_mbox_ops,
103 };
104