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/of_platform.h>
12 #include <linux/platform_device.h>
13 #include <linux/slab.h>
14 
15 static const char * const adsp_mbox_ch_names[MTK_ADSP_MBOX_NUM] = { "rx", "tx" };
16 
17 /*
18  * mtk_adsp_ipc_send - send ipc cmd to MTK ADSP
19  *
20  * @ipc: ADSP IPC handle
21  * @idx: index of the mailbox channel
22  * @msg: IPC cmd (reply or request)
23  *
24  * Returns zero for success from mbox_send_message
25  * negative value for error
26  */
27 int mtk_adsp_ipc_send(struct mtk_adsp_ipc *ipc, unsigned int idx, uint32_t msg)
28 {
29 	struct mtk_adsp_chan *adsp_chan;
30 	int ret;
31 
32 	if (idx >= MTK_ADSP_MBOX_NUM)
33 		return -EINVAL;
34 
35 	adsp_chan = &ipc->chans[idx];
36 	ret = mbox_send_message(adsp_chan->ch, &msg);
37 	if (ret < 0)
38 		return ret;
39 
40 	return 0;
41 }
42 EXPORT_SYMBOL_GPL(mtk_adsp_ipc_send);
43 
44 /*
45  * mtk_adsp_ipc_recv - recv callback used by MTK ADSP mailbox
46  *
47  * @c: mbox client
48  * @msg: message received
49  *
50  * Users of ADSP IPC will need to privde handle_reply and handle_request
51  * callbacks.
52  */
53 static void mtk_adsp_ipc_recv(struct mbox_client *c, void *msg)
54 {
55 	struct mtk_adsp_chan *chan = container_of(c, struct mtk_adsp_chan, cl);
56 	struct device *dev = c->dev;
57 
58 	switch (chan->idx) {
59 	case MTK_ADSP_MBOX_REPLY:
60 		chan->ipc->ops->handle_reply(chan->ipc);
61 		break;
62 	case MTK_ADSP_MBOX_REQUEST:
63 		chan->ipc->ops->handle_request(chan->ipc);
64 		break;
65 	default:
66 		dev_err(dev, "wrong mbox chan %d\n", chan->idx);
67 		break;
68 	}
69 }
70 
71 static int mtk_adsp_ipc_probe(struct platform_device *pdev)
72 {
73 	struct device *dev = &pdev->dev;
74 	struct mtk_adsp_ipc *adsp_ipc;
75 	struct mtk_adsp_chan *adsp_chan;
76 	struct mbox_client *cl;
77 	int ret;
78 	int i, j;
79 
80 	device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent);
81 
82 	adsp_ipc = devm_kzalloc(dev, sizeof(*adsp_ipc), GFP_KERNEL);
83 	if (!adsp_ipc)
84 		return -ENOMEM;
85 
86 	for (i = 0; i < MTK_ADSP_MBOX_NUM; i++) {
87 		adsp_chan = &adsp_ipc->chans[i];
88 		cl = &adsp_chan->cl;
89 		cl->dev = dev->parent;
90 		cl->tx_block = false;
91 		cl->knows_txdone = false;
92 		cl->tx_prepare = NULL;
93 		cl->rx_callback = mtk_adsp_ipc_recv;
94 
95 		adsp_chan->ipc = adsp_ipc;
96 		adsp_chan->idx = i;
97 		adsp_chan->ch = mbox_request_channel_byname(cl, adsp_mbox_ch_names[i]);
98 		if (IS_ERR(adsp_chan->ch)) {
99 			ret = PTR_ERR(adsp_chan->ch);
100 			if (ret != -EPROBE_DEFER)
101 				dev_err(dev, "Failed to request mbox chan %s ret %d\n",
102 					adsp_mbox_ch_names[i], ret);
103 
104 			for (j = 0; j < i; j++) {
105 				adsp_chan = &adsp_ipc->chans[j];
106 				mbox_free_channel(adsp_chan->ch);
107 			}
108 
109 			return ret;
110 		}
111 	}
112 
113 	adsp_ipc->dev = dev;
114 	dev_set_drvdata(dev, adsp_ipc);
115 	dev_dbg(dev, "MTK ADSP IPC initialized\n");
116 
117 	return 0;
118 }
119 
120 static int mtk_adsp_ipc_remove(struct platform_device *pdev)
121 {
122 	struct mtk_adsp_ipc *adsp_ipc = dev_get_drvdata(&pdev->dev);
123 	struct mtk_adsp_chan *adsp_chan;
124 	int i;
125 
126 	for (i = 0; i < MTK_ADSP_MBOX_NUM; i++) {
127 		adsp_chan = &adsp_ipc->chans[i];
128 		mbox_free_channel(adsp_chan->ch);
129 	}
130 
131 	return 0;
132 }
133 
134 static struct platform_driver mtk_adsp_ipc_driver = {
135 	.driver = {
136 		.name = "mtk-adsp-ipc",
137 	},
138 	.probe = mtk_adsp_ipc_probe,
139 	.remove = mtk_adsp_ipc_remove,
140 };
141 builtin_platform_driver(mtk_adsp_ipc_driver);
142 
143 MODULE_AUTHOR("Allen-KH Cheng <allen-kh.cheng@mediatek.com>");
144 MODULE_DESCRIPTION("MTK ADSP IPC Driver");
145 MODULE_LICENSE("GPL");
146