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11#include <linux/interrupt.h>
12#include <linux/spinlock.h>
13#include <linux/mutex.h>
14#include <linux/delay.h>
15#include <linux/slab.h>
16#include <linux/err.h>
17#include <linux/io.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
20#include <linux/mailbox_controller.h>
21
22#define INTR_SET_OFS 0x0
23#define INTR_STAT_OFS 0x4
24#define INTR_CLR_OFS 0x8
25
26#define MHU_SEC_OFFSET 0x0
27#define MHU_LP_OFFSET 0xc
28#define MHU_HP_OFFSET 0x18
29#define TX_REG_OFFSET 0x24
30
31#define MHU_CHANS 3
32
33struct platform_mhu_link {
34 int irq;
35 void __iomem *tx_reg;
36 void __iomem *rx_reg;
37};
38
39struct platform_mhu {
40 void __iomem *base;
41 struct platform_mhu_link mlink[MHU_CHANS];
42 struct mbox_chan chan[MHU_CHANS];
43 struct mbox_controller mbox;
44};
45
46static irqreturn_t platform_mhu_rx_interrupt(int irq, void *p)
47{
48 struct mbox_chan *chan = p;
49 struct platform_mhu_link *mlink = chan->con_priv;
50 u32 val;
51
52 val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS);
53 if (!val)
54 return IRQ_NONE;
55
56 mbox_chan_received_data(chan, (void *)&val);
57
58 writel_relaxed(val, mlink->rx_reg + INTR_CLR_OFS);
59
60 return IRQ_HANDLED;
61}
62
63static bool platform_mhu_last_tx_done(struct mbox_chan *chan)
64{
65 struct platform_mhu_link *mlink = chan->con_priv;
66 u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
67
68 return (val == 0);
69}
70
71static int platform_mhu_send_data(struct mbox_chan *chan, void *data)
72{
73 struct platform_mhu_link *mlink = chan->con_priv;
74 u32 *arg = data;
75
76 writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS);
77
78 return 0;
79}
80
81static int platform_mhu_startup(struct mbox_chan *chan)
82{
83 struct platform_mhu_link *mlink = chan->con_priv;
84 u32 val;
85 int ret;
86
87 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
88 writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS);
89
90 ret = request_irq(mlink->irq, platform_mhu_rx_interrupt,
91 IRQF_SHARED, "platform_mhu_link", chan);
92 if (ret) {
93 dev_err(chan->mbox->dev,
94 "Unable to acquire IRQ %d\n", mlink->irq);
95 return ret;
96 }
97
98 return 0;
99}
100
101static void platform_mhu_shutdown(struct mbox_chan *chan)
102{
103 struct platform_mhu_link *mlink = chan->con_priv;
104
105 free_irq(mlink->irq, chan);
106}
107
108static const struct mbox_chan_ops platform_mhu_ops = {
109 .send_data = platform_mhu_send_data,
110 .startup = platform_mhu_startup,
111 .shutdown = platform_mhu_shutdown,
112 .last_tx_done = platform_mhu_last_tx_done,
113};
114
115static int platform_mhu_probe(struct platform_device *pdev)
116{
117 int i, err;
118 struct platform_mhu *mhu;
119 struct device *dev = &pdev->dev;
120 struct resource *res;
121 int platform_mhu_reg[MHU_CHANS] = {
122 MHU_SEC_OFFSET, MHU_LP_OFFSET, MHU_HP_OFFSET
123 };
124
125
126 mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
127 if (!mhu)
128 return -ENOMEM;
129
130 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
131 mhu->base = devm_ioremap_resource(dev, res);
132 if (IS_ERR(mhu->base)) {
133 dev_err(dev, "ioremap failed\n");
134 return PTR_ERR(mhu->base);
135 }
136
137 for (i = 0; i < MHU_CHANS; i++) {
138 mhu->chan[i].con_priv = &mhu->mlink[i];
139 mhu->mlink[i].irq = platform_get_irq(pdev, i);
140 if (mhu->mlink[i].irq < 0) {
141 dev_err(dev, "failed to get irq%d\n", i);
142 return mhu->mlink[i].irq;
143 }
144 mhu->mlink[i].rx_reg = mhu->base + platform_mhu_reg[i];
145 mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;
146 }
147
148 mhu->mbox.dev = dev;
149 mhu->mbox.chans = &mhu->chan[0];
150 mhu->mbox.num_chans = MHU_CHANS;
151 mhu->mbox.ops = &platform_mhu_ops;
152 mhu->mbox.txdone_irq = false;
153 mhu->mbox.txdone_poll = true;
154 mhu->mbox.txpoll_period = 1;
155
156 platform_set_drvdata(pdev, mhu);
157
158 err = devm_mbox_controller_register(dev, &mhu->mbox);
159 if (err) {
160 dev_err(dev, "Failed to register mailboxes %d\n", err);
161 return err;
162 }
163
164 dev_info(dev, "Platform MHU Mailbox registered\n");
165 return 0;
166}
167
168static const struct of_device_id platform_mhu_dt_ids[] = {
169 { .compatible = "amlogic,meson-gxbb-mhu", },
170 { },
171};
172MODULE_DEVICE_TABLE(of, platform_mhu_dt_ids);
173
174static struct platform_driver platform_mhu_driver = {
175 .probe = platform_mhu_probe,
176 .driver = {
177 .name = "platform-mhu",
178 .of_match_table = platform_mhu_dt_ids,
179 },
180};
181
182module_platform_driver(platform_mhu_driver);
183
184MODULE_LICENSE("GPL v2");
185MODULE_ALIAS("platform:platform-mhu");
186MODULE_DESCRIPTION("Platform MHU Driver");
187MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
188
