1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2022 MediaTek Corporation. All rights reserved.
4 * Author: Allen-KH Cheng <allen-kh.cheng@mediatek.com>
5 */
6
7#include <linux/firmware/mediatek/mtk-adsp-ipc.h>
8#include <linux/kernel.h>
9#include <linux/mailbox_client.h>
10#include <linux/module.h>
11#include <linux/platform_device.h>
12#include <linux/slab.h>
13
14static const char * const adsp_mbox_ch_names[MTK_ADSP_MBOX_NUM] = { "rx", "tx" };
15
16/*
17 * mtk_adsp_ipc_send - send ipc cmd to MTK ADSP
18 *
19 * @ipc: ADSP IPC handle
20 * @idx: index of the mailbox channel
21 * @msg: IPC cmd (reply or request)
22 *
23 * Returns zero for success from mbox_send_message
24 * negative value for error
25 */
26int mtk_adsp_ipc_send(struct mtk_adsp_ipc *ipc, unsigned int idx, uint32_t msg)
27{
28	struct mtk_adsp_chan *adsp_chan;
29	int ret;
30
31	if (idx >= MTK_ADSP_MBOX_NUM)
32		return -EINVAL;
33
34	adsp_chan = &ipc->chans[idx];
35	ret = mbox_send_message(adsp_chan->ch, &msg);
36	if (ret < 0)
37		return ret;
38
39	return 0;
40}
41EXPORT_SYMBOL_GPL(mtk_adsp_ipc_send);
42
43/*
44 * mtk_adsp_ipc_recv - recv callback used by MTK ADSP mailbox
45 *
46 * @c: mbox client
47 * @msg: message received
48 *
49 * Users of ADSP IPC will need to privde handle_reply and handle_request
50 * callbacks.
51 */
52static void mtk_adsp_ipc_recv(struct mbox_client *c, void *msg)
53{
54	struct mtk_adsp_chan *chan = container_of(c, struct mtk_adsp_chan, cl);
55	struct device *dev = c->dev;
56
57	switch (chan->idx) {
58	case MTK_ADSP_MBOX_REPLY:
59		chan->ipc->ops->handle_reply(chan->ipc);
60		break;
61	case MTK_ADSP_MBOX_REQUEST:
62		chan->ipc->ops->handle_request(chan->ipc);
63		break;
64	default:
65		dev_err(dev, "wrong mbox chan %d\n", chan->idx);
66		break;
67	}
68}
69
70static int mtk_adsp_ipc_probe(struct platform_device *pdev)
71{
72	struct device *dev = &pdev->dev;
73	struct mtk_adsp_ipc *adsp_ipc;
74	struct mtk_adsp_chan *adsp_chan;
75	struct mbox_client *cl;
76	int ret;
77	int i, j;
78
79	device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent);
80
81	adsp_ipc = devm_kzalloc(dev, sizeof(*adsp_ipc), GFP_KERNEL);
82	if (!adsp_ipc)
83		return -ENOMEM;
84
85	for (i = 0; i < MTK_ADSP_MBOX_NUM; i++) {
86		adsp_chan = &adsp_ipc->chans[i];
87		cl = &adsp_chan->cl;
88		cl->dev = dev->parent;
89		cl->tx_block = false;
90		cl->knows_txdone = false;
91		cl->tx_prepare = NULL;
92		cl->rx_callback = mtk_adsp_ipc_recv;
93
94		adsp_chan->ipc = adsp_ipc;
95		adsp_chan->idx = i;
96		adsp_chan->ch = mbox_request_channel_byname(cl, adsp_mbox_ch_names[i]);
97		if (IS_ERR(adsp_chan->ch)) {
98			ret = PTR_ERR(adsp_chan->ch);
99			if (ret != -EPROBE_DEFER)
100				dev_err(dev, "Failed to request mbox chan %s ret %d\n",
101					adsp_mbox_ch_names[i], ret);
102
103			for (j = 0; j < i; j++) {
104				adsp_chan = &adsp_ipc->chans[j];
105				mbox_free_channel(adsp_chan->ch);
106			}
107
108			return ret;
109		}
110	}
111
112	adsp_ipc->dev = dev;
113	dev_set_drvdata(dev, adsp_ipc);
114	dev_dbg(dev, "MTK ADSP IPC initialized\n");
115
116	return 0;
117}
118
119static int mtk_adsp_ipc_remove(struct platform_device *pdev)
120{
121	struct mtk_adsp_ipc *adsp_ipc = dev_get_drvdata(&pdev->dev);
122	struct mtk_adsp_chan *adsp_chan;
123	int i;
124
125	for (i = 0; i < MTK_ADSP_MBOX_NUM; i++) {
126		adsp_chan = &adsp_ipc->chans[i];
127		mbox_free_channel(adsp_chan->ch);
128	}
129
130	return 0;
131}
132
133static struct platform_driver mtk_adsp_ipc_driver = {
134	.driver = {
135		.name = "mtk-adsp-ipc",
136	},
137	.probe = mtk_adsp_ipc_probe,
138	.remove = mtk_adsp_ipc_remove,
139};
140builtin_platform_driver(mtk_adsp_ipc_driver);
141
142MODULE_AUTHOR("Allen-KH Cheng <allen-kh.cheng@mediatek.com>");
143MODULE_DESCRIPTION("MTK ADSP IPC Driver");
144MODULE_LICENSE("GPL");
145