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/interrupt.h>
8 #include <linux/io.h>
9 #include <linux/iopoll.h>
10 #include <linux/kernel.h>
11 #include <linux/mailbox_controller.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 
17 struct mtk_adsp_mbox_priv {
18 	struct device *dev;
19 	struct mbox_controller mbox;
20 	void __iomem *va_mboxreg;
21 	const struct mtk_adsp_mbox_cfg *cfg;
22 };
23 
24 struct mtk_adsp_mbox_cfg {
25 	u32 set_in;
26 	u32 set_out;
27 	u32 clr_in;
28 	u32 clr_out;
29 };
30 
31 static inline struct mtk_adsp_mbox_priv *get_mtk_adsp_mbox_priv(struct mbox_controller *mbox)
32 {
33 	return container_of(mbox, struct mtk_adsp_mbox_priv, mbox);
34 }
35 
36 static irqreturn_t mtk_adsp_mbox_irq(int irq, void *data)
37 {
38 	struct mbox_chan *chan = data;
39 	struct mtk_adsp_mbox_priv *priv = get_mtk_adsp_mbox_priv(chan->mbox);
40 	u32 op = readl(priv->va_mboxreg + priv->cfg->set_out);
41 
42 	writel(op, priv->va_mboxreg + priv->cfg->clr_out);
43 
44 	return IRQ_WAKE_THREAD;
45 }
46 
47 static irqreturn_t mtk_adsp_mbox_isr(int irq, void *data)
48 {
49 	struct mbox_chan *chan = data;
50 
51 	mbox_chan_received_data(chan, NULL);
52 
53 	return IRQ_HANDLED;
54 }
55 
56 static struct mbox_chan *mtk_adsp_mbox_xlate(struct mbox_controller *mbox,
57 					     const struct of_phandle_args *sp)
58 {
59 	return mbox->chans;
60 }
61 
62 static int mtk_adsp_mbox_startup(struct mbox_chan *chan)
63 {
64 	struct mtk_adsp_mbox_priv *priv = get_mtk_adsp_mbox_priv(chan->mbox);
65 
66 	/* Clear ADSP mbox command */
67 	writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_in);
68 	writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_out);
69 
70 	return 0;
71 }
72 
73 static void mtk_adsp_mbox_shutdown(struct mbox_chan *chan)
74 {
75 	struct mtk_adsp_mbox_priv *priv = get_mtk_adsp_mbox_priv(chan->mbox);
76 
77 	/* Clear ADSP mbox command */
78 	writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_in);
79 	writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_out);
80 }
81 
82 static int mtk_adsp_mbox_send_data(struct mbox_chan *chan, void *data)
83 {
84 	struct mtk_adsp_mbox_priv *priv = get_mtk_adsp_mbox_priv(chan->mbox);
85 	u32 *msg = data;
86 
87 	writel(*msg, priv->va_mboxreg + priv->cfg->set_in);
88 
89 	return 0;
90 }
91 
92 static bool mtk_adsp_mbox_last_tx_done(struct mbox_chan *chan)
93 {
94 	struct mtk_adsp_mbox_priv *priv = get_mtk_adsp_mbox_priv(chan->mbox);
95 
96 	return readl(priv->va_mboxreg + priv->cfg->set_in) == 0;
97 }
98 
99 static const struct mbox_chan_ops mtk_adsp_mbox_chan_ops = {
100 	.send_data	= mtk_adsp_mbox_send_data,
101 	.startup	= mtk_adsp_mbox_startup,
102 	.shutdown	= mtk_adsp_mbox_shutdown,
103 	.last_tx_done	= mtk_adsp_mbox_last_tx_done,
104 };
105 
106 static int mtk_adsp_mbox_probe(struct platform_device *pdev)
107 {
108 	struct device *dev = &pdev->dev;
109 	struct mtk_adsp_mbox_priv *priv;
110 	const struct mtk_adsp_mbox_cfg *cfg;
111 	struct mbox_controller *mbox;
112 	int ret, irq;
113 
114 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
115 	if (!priv)
116 		return -ENOMEM;
117 
118 	mbox = &priv->mbox;
119 	mbox->dev = dev;
120 	mbox->ops = &mtk_adsp_mbox_chan_ops;
121 	mbox->txdone_irq = false;
122 	mbox->txdone_poll = true;
123 	mbox->of_xlate = mtk_adsp_mbox_xlate;
124 	mbox->num_chans = 1;
125 	mbox->chans = devm_kzalloc(dev, sizeof(*mbox->chans), GFP_KERNEL);
126 	if (!mbox->chans)
127 		return -ENOMEM;
128 
129 	priv->va_mboxreg = devm_platform_ioremap_resource(pdev, 0);
130 	if (IS_ERR(priv->va_mboxreg))
131 		return PTR_ERR(priv->va_mboxreg);
132 
133 	cfg = of_device_get_match_data(dev);
134 	if (!cfg)
135 		return -EINVAL;
136 	priv->cfg = cfg;
137 
138 	irq = platform_get_irq(pdev, 0);
139 	if (irq < 0)
140 		return irq;
141 
142 	ret = devm_request_threaded_irq(dev, irq, mtk_adsp_mbox_irq,
143 					mtk_adsp_mbox_isr, IRQF_TRIGGER_NONE,
144 					dev_name(dev), mbox->chans);
145 	if (ret < 0)
146 		return ret;
147 
148 	platform_set_drvdata(pdev, priv);
149 
150 	return devm_mbox_controller_register(dev, &priv->mbox);
151 }
152 
153 static const struct mtk_adsp_mbox_cfg mt8186_adsp_mbox_cfg = {
154 	.set_in		= 0x00,
155 	.set_out	= 0x04,
156 	.clr_in		= 0x08,
157 	.clr_out	= 0x0C,
158 };
159 
160 static const struct mtk_adsp_mbox_cfg mt8195_adsp_mbox_cfg = {
161 	.set_in		= 0x00,
162 	.set_out	= 0x1c,
163 	.clr_in		= 0x04,
164 	.clr_out	= 0x20,
165 };
166 
167 static const struct of_device_id mtk_adsp_mbox_of_match[] = {
168 	{ .compatible = "mediatek,mt8186-adsp-mbox", .data = &mt8186_adsp_mbox_cfg },
169 	{ .compatible = "mediatek,mt8195-adsp-mbox", .data = &mt8195_adsp_mbox_cfg },
170 	{},
171 };
172 MODULE_DEVICE_TABLE(of, mtk_adsp_mbox_of_match);
173 
174 static struct platform_driver mtk_adsp_mbox_driver = {
175 	.probe		= mtk_adsp_mbox_probe,
176 	.driver = {
177 		.name	= "mtk_adsp_mbox",
178 		.of_match_table = mtk_adsp_mbox_of_match,
179 	},
180 };
181 module_platform_driver(mtk_adsp_mbox_driver);
182 
183 MODULE_AUTHOR("Allen-KH Cheng <Allen-KH.Cheng@mediatek.com>");
184 MODULE_DESCRIPTION("MTK ADSP Mailbox Controller");
185 MODULE_LICENSE("GPL v2");
186