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 
14 static 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  */
26 int 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 }
41 EXPORT_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  */
52 static 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 
70 static 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 
119 static 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 
133 static 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 };
140 builtin_platform_driver(mtk_adsp_ipc_driver);
141 
142 MODULE_AUTHOR("Allen-KH Cheng <allen-kh.cheng@mediatek.com>");
143 MODULE_DESCRIPTION("MTK ADSP IPC Driver");
144 MODULE_LICENSE("GPL");
145