1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2024 Sophgo Technology Inc.
4 * Copyright (C) 2024 Yuntao Dai <d1581209858@live.com>
5 * Copyright (C) 2025 Junhui Liu <junhui.liu@pigmoral.tech>
6 */
7
8 #include <linux/bits.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/kfifo.h>
14 #include <linux/mailbox_client.h>
15 #include <linux/mailbox_controller.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19
20 #define RECV_CPU 1
21
22 #define MAILBOX_MAX_CHAN 8
23 #define MAILBOX_MSG_LEN 8
24
25 #define MBOX_EN_REG(cpu) (cpu << 2)
26 #define MBOX_DONE_REG(cpu) ((cpu << 2) + 2)
27 #define MBOX_SET_CLR_REG(cpu) (0x10 + (cpu << 4))
28 #define MBOX_SET_INT_REG(cpu) (0x18 + (cpu << 4))
29 #define MBOX_SET_REG 0x60
30
31 #define MAILBOX_CONTEXT_OFFSET 0x0400
32 #define MAILBOX_CONTEXT_SIZE 0x0040
33
34 #define MBOX_CONTEXT_BASE_INDEX(base, index) \
35 ((u64 __iomem *)(base + MAILBOX_CONTEXT_OFFSET) + index)
36
37 /**
38 * struct cv1800_mbox_chan_priv - cv1800 mailbox channel private data
39 * @idx: index of channel
40 * @cpu: send to which processor
41 */
42 struct cv1800_mbox_chan_priv {
43 int idx;
44 int cpu;
45 };
46
47 struct cv1800_mbox {
48 struct mbox_controller mbox;
49 struct cv1800_mbox_chan_priv priv[MAILBOX_MAX_CHAN];
50 struct mbox_chan chans[MAILBOX_MAX_CHAN];
51 u64 __iomem *content[MAILBOX_MAX_CHAN];
52 void __iomem *mbox_base;
53 int recvid;
54 };
55
cv1800_mbox_isr(int irq,void * dev_id)56 static irqreturn_t cv1800_mbox_isr(int irq, void *dev_id)
57 {
58 struct cv1800_mbox *mbox = (struct cv1800_mbox *)dev_id;
59 size_t i;
60 u64 msg;
61 int ret = IRQ_NONE;
62
63 for (i = 0; i < MAILBOX_MAX_CHAN; i++) {
64 if (mbox->content[i] && mbox->chans[i].cl) {
65 memcpy_fromio(&msg, mbox->content[i], MAILBOX_MSG_LEN);
66 mbox->content[i] = NULL;
67 mbox_chan_received_data(&mbox->chans[i], (void *)&msg);
68 ret = IRQ_HANDLED;
69 }
70 }
71
72 return ret;
73 }
74
cv1800_mbox_irq(int irq,void * dev_id)75 static irqreturn_t cv1800_mbox_irq(int irq, void *dev_id)
76 {
77 struct cv1800_mbox *mbox = (struct cv1800_mbox *)dev_id;
78 u8 set, valid;
79 size_t i;
80 int ret = IRQ_NONE;
81
82 set = readb(mbox->mbox_base + MBOX_SET_INT_REG(RECV_CPU));
83
84 if (!set)
85 return ret;
86
87 for (i = 0; i < MAILBOX_MAX_CHAN; i++) {
88 valid = set & BIT(i);
89 if (valid) {
90 mbox->content[i] =
91 MBOX_CONTEXT_BASE_INDEX(mbox->mbox_base, i);
92 writeb(valid, mbox->mbox_base +
93 MBOX_SET_CLR_REG(RECV_CPU));
94 writeb(~valid, mbox->mbox_base + MBOX_EN_REG(RECV_CPU));
95 ret = IRQ_WAKE_THREAD;
96 }
97 }
98
99 return ret;
100 }
101
cv1800_mbox_send_data(struct mbox_chan * chan,void * data)102 static int cv1800_mbox_send_data(struct mbox_chan *chan, void *data)
103 {
104 struct cv1800_mbox_chan_priv *priv =
105 (struct cv1800_mbox_chan_priv *)chan->con_priv;
106 struct cv1800_mbox *mbox = dev_get_drvdata(chan->mbox->dev);
107 int idx = priv->idx;
108 int cpu = priv->cpu;
109 u8 en, valid;
110
111 memcpy_toio(MBOX_CONTEXT_BASE_INDEX(mbox->mbox_base, idx),
112 data, MAILBOX_MSG_LEN);
113
114 valid = BIT(idx);
115 writeb(valid, mbox->mbox_base + MBOX_SET_CLR_REG(cpu));
116 en = readb(mbox->mbox_base + MBOX_EN_REG(cpu));
117 writeb(en | valid, mbox->mbox_base + MBOX_EN_REG(cpu));
118 writeb(valid, mbox->mbox_base + MBOX_SET_REG);
119
120 return 0;
121 }
122
cv1800_last_tx_done(struct mbox_chan * chan)123 static bool cv1800_last_tx_done(struct mbox_chan *chan)
124 {
125 struct cv1800_mbox_chan_priv *priv =
126 (struct cv1800_mbox_chan_priv *)chan->con_priv;
127 struct cv1800_mbox *mbox = dev_get_drvdata(chan->mbox->dev);
128 u8 en;
129
130 en = readb(mbox->mbox_base + MBOX_EN_REG(priv->cpu));
131
132 return !(en & BIT(priv->idx));
133 }
134
135 static const struct mbox_chan_ops cv1800_mbox_chan_ops = {
136 .send_data = cv1800_mbox_send_data,
137 .last_tx_done = cv1800_last_tx_done,
138 };
139
cv1800_mbox_xlate(struct mbox_controller * mbox,const struct of_phandle_args * spec)140 static struct mbox_chan *cv1800_mbox_xlate(struct mbox_controller *mbox,
141 const struct of_phandle_args *spec)
142 {
143 struct cv1800_mbox_chan_priv *priv;
144
145 int idx = spec->args[0];
146 int cpu = spec->args[1];
147
148 if (idx >= mbox->num_chans)
149 return ERR_PTR(-EINVAL);
150
151 priv = mbox->chans[idx].con_priv;
152 priv->cpu = cpu;
153
154 return &mbox->chans[idx];
155 }
156
157 static const struct of_device_id cv1800_mbox_of_match[] = {
158 { .compatible = "sophgo,cv1800b-mailbox", },
159 {},
160 };
161 MODULE_DEVICE_TABLE(of, cv1800_mbox_of_match);
162
cv1800_mbox_probe(struct platform_device * pdev)163 static int cv1800_mbox_probe(struct platform_device *pdev)
164 {
165 struct device *dev = &pdev->dev;
166 struct cv1800_mbox *mb;
167 int irq, idx, err;
168
169 mb = devm_kzalloc(dev, sizeof(*mb), GFP_KERNEL);
170 if (!mb)
171 return -ENOMEM;
172
173 mb->mbox_base = devm_platform_ioremap_resource(pdev, 0);
174 if (IS_ERR(mb->mbox_base))
175 return dev_err_probe(dev, PTR_ERR(mb->mbox_base),
176 "Failed to map resource\n");
177
178 mb->mbox.dev = dev;
179 mb->mbox.chans = mb->chans;
180 mb->mbox.txdone_poll = true;
181 mb->mbox.ops = &cv1800_mbox_chan_ops;
182 mb->mbox.num_chans = MAILBOX_MAX_CHAN;
183 mb->mbox.of_xlate = cv1800_mbox_xlate;
184
185 irq = platform_get_irq(pdev, 0);
186 if (irq < 0)
187 return irq;
188
189 err = devm_request_threaded_irq(dev, irq, cv1800_mbox_irq,
190 cv1800_mbox_isr, IRQF_ONESHOT,
191 dev_name(&pdev->dev), mb);
192 if (err < 0)
193 return dev_err_probe(dev, err, "Failed to register irq\n");
194
195 for (idx = 0; idx < MAILBOX_MAX_CHAN; idx++) {
196 mb->priv[idx].idx = idx;
197 mb->mbox.chans[idx].con_priv = &mb->priv[idx];
198 }
199
200 platform_set_drvdata(pdev, mb);
201
202 err = devm_mbox_controller_register(dev, &mb->mbox);
203 if (err)
204 return dev_err_probe(dev, err, "Failed to register mailbox\n");
205
206 return 0;
207 }
208
209 static struct platform_driver cv1800_mbox_driver = {
210 .driver = {
211 .name = "cv1800-mbox",
212 .of_match_table = cv1800_mbox_of_match,
213 },
214 .probe = cv1800_mbox_probe,
215 };
216
217 module_platform_driver(cv1800_mbox_driver);
218
219 MODULE_DESCRIPTION("cv1800 mailbox driver");
220 MODULE_LICENSE("GPL");
221