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5#include <linux/bitops.h>
6#include <linux/delay.h>
7#include <linux/device.h>
8#include <linux/err.h>
9#include <linux/interrupt.h>
10#include <linux/io.h>
11#include <linux/iopoll.h>
12#include <linux/mailbox_controller.h>
13#include <linux/module.h>
14#include <linux/platform_device.h>
15#include <linux/slab.h>
16
17#include "mailbox.h"
18
19#define MBOX_CHAN_MAX 32
20
21#define MBOX_RX 0x0
22#define MBOX_TX 0x1
23
24#define MBOX_BASE(mbox, ch) ((mbox)->base + ((ch) * 0x40))
25#define MBOX_SRC_REG 0x00
26#define MBOX_DST_REG 0x04
27#define MBOX_DCLR_REG 0x08
28#define MBOX_DSTAT_REG 0x0c
29#define MBOX_MODE_REG 0x10
30#define MBOX_IMASK_REG 0x14
31#define MBOX_ICLR_REG 0x18
32#define MBOX_SEND_REG 0x1c
33#define MBOX_DATA_REG 0x20
34
35#define MBOX_IPC_LOCK_REG 0xa00
36#define MBOX_IPC_UNLOCK 0x1acce551
37
38#define MBOX_AUTOMATIC_ACK 1
39
40#define MBOX_STATE_IDLE BIT(4)
41#define MBOX_STATE_READY BIT(5)
42#define MBOX_STATE_ACK BIT(7)
43
44#define MBOX_MSG_LEN 8
45
46
47
48
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53
54
55
56struct hi3660_chan_info {
57 unsigned int dst_irq;
58 unsigned int ack_irq;
59};
60
61
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71
72
73struct hi3660_mbox {
74 struct device *dev;
75 void __iomem *base;
76 struct mbox_chan chan[MBOX_CHAN_MAX];
77 struct hi3660_chan_info mchan[MBOX_CHAN_MAX];
78 struct mbox_controller controller;
79};
80
81static struct hi3660_mbox *to_hi3660_mbox(struct mbox_controller *mbox)
82{
83 return container_of(mbox, struct hi3660_mbox, controller);
84}
85
86static int hi3660_mbox_check_state(struct mbox_chan *chan)
87{
88 unsigned long ch = (unsigned long)chan->con_priv;
89 struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
90 struct hi3660_chan_info *mchan = &mbox->mchan[ch];
91 void __iomem *base = MBOX_BASE(mbox, ch);
92 unsigned long val;
93 unsigned int ret;
94
95
96 if (readl(base + MBOX_MODE_REG) & MBOX_STATE_READY)
97 return 0;
98
99
100 ret = readx_poll_timeout_atomic(readl, base + MBOX_MODE_REG,
101 val, (val & MBOX_STATE_ACK), 1000, 300000);
102 if (ret) {
103 dev_err(mbox->dev, "%s: timeout for receiving ack\n", __func__);
104 return ret;
105 }
106
107
108 writel(BIT(mchan->ack_irq), base + MBOX_ICLR_REG);
109
110 return 0;
111}
112
113static int hi3660_mbox_unlock(struct mbox_chan *chan)
114{
115 struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
116 unsigned int val, retry = 3;
117
118 do {
119 writel(MBOX_IPC_UNLOCK, mbox->base + MBOX_IPC_LOCK_REG);
120
121 val = readl(mbox->base + MBOX_IPC_LOCK_REG);
122 if (!val)
123 break;
124
125 udelay(10);
126 } while (retry--);
127
128 if (val)
129 dev_err(mbox->dev, "%s: failed to unlock mailbox\n", __func__);
130
131 return (!val) ? 0 : -ETIMEDOUT;
132}
133
134static int hi3660_mbox_acquire_channel(struct mbox_chan *chan)
135{
136 unsigned long ch = (unsigned long)chan->con_priv;
137 struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
138 struct hi3660_chan_info *mchan = &mbox->mchan[ch];
139 void __iomem *base = MBOX_BASE(mbox, ch);
140 unsigned int val, retry;
141
142 for (retry = 10; retry; retry--) {
143
144 if (readl(base + MBOX_MODE_REG) & MBOX_STATE_IDLE) {
145 writel(BIT(mchan->ack_irq), base + MBOX_SRC_REG);
146
147
148 val = readl(base + MBOX_SRC_REG);
149 if (val & BIT(mchan->ack_irq))
150 break;
151 }
152 }
153
154 if (!retry)
155 dev_err(mbox->dev, "%s: failed to acquire channel\n", __func__);
156
157 return retry ? 0 : -ETIMEDOUT;
158}
159
160static int hi3660_mbox_startup(struct mbox_chan *chan)
161{
162 int ret;
163
164 ret = hi3660_mbox_unlock(chan);
165 if (ret)
166 return ret;
167
168 ret = hi3660_mbox_acquire_channel(chan);
169 if (ret)
170 return ret;
171
172 return 0;
173}
174
175static int hi3660_mbox_send_data(struct mbox_chan *chan, void *msg)
176{
177 unsigned long ch = (unsigned long)chan->con_priv;
178 struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
179 struct hi3660_chan_info *mchan = &mbox->mchan[ch];
180 void __iomem *base = MBOX_BASE(mbox, ch);
181 u32 *buf = msg;
182 unsigned int i;
183 int ret;
184
185 ret = hi3660_mbox_check_state(chan);
186 if (ret)
187 return ret;
188
189
190 writel_relaxed(~BIT(mchan->dst_irq), base + MBOX_IMASK_REG);
191
192
193 writel_relaxed(BIT(mchan->dst_irq), base + MBOX_DST_REG);
194
195
196 writel_relaxed(MBOX_AUTOMATIC_ACK, base + MBOX_MODE_REG);
197
198
199 for (i = 0; i < MBOX_MSG_LEN; i++)
200 writel_relaxed(buf[i], base + MBOX_DATA_REG + i * 4);
201
202
203 writel(BIT(mchan->ack_irq), base + MBOX_SEND_REG);
204 return 0;
205}
206
207static const struct mbox_chan_ops hi3660_mbox_ops = {
208 .startup = hi3660_mbox_startup,
209 .send_data = hi3660_mbox_send_data,
210};
211
212static struct mbox_chan *hi3660_mbox_xlate(struct mbox_controller *controller,
213 const struct of_phandle_args *spec)
214{
215 struct hi3660_mbox *mbox = to_hi3660_mbox(controller);
216 struct hi3660_chan_info *mchan;
217 unsigned int ch = spec->args[0];
218
219 if (ch >= MBOX_CHAN_MAX) {
220 dev_err(mbox->dev, "Invalid channel idx %d\n", ch);
221 return ERR_PTR(-EINVAL);
222 }
223
224 mchan = &mbox->mchan[ch];
225 mchan->dst_irq = spec->args[1];
226 mchan->ack_irq = spec->args[2];
227
228 return &mbox->chan[ch];
229}
230
231static const struct of_device_id hi3660_mbox_of_match[] = {
232 { .compatible = "hisilicon,hi3660-mbox", },
233 {},
234};
235
236MODULE_DEVICE_TABLE(of, hi3660_mbox_of_match);
237
238static int hi3660_mbox_probe(struct platform_device *pdev)
239{
240 struct device *dev = &pdev->dev;
241 struct hi3660_mbox *mbox;
242 struct mbox_chan *chan;
243 struct resource *res;
244 unsigned long ch;
245 int err;
246
247 mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
248 if (!mbox)
249 return -ENOMEM;
250
251 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
252 mbox->base = devm_ioremap_resource(dev, res);
253 if (IS_ERR(mbox->base))
254 return PTR_ERR(mbox->base);
255
256 mbox->dev = dev;
257 mbox->controller.dev = dev;
258 mbox->controller.chans = mbox->chan;
259 mbox->controller.num_chans = MBOX_CHAN_MAX;
260 mbox->controller.ops = &hi3660_mbox_ops;
261 mbox->controller.of_xlate = hi3660_mbox_xlate;
262
263
264 chan = mbox->chan;
265 for (ch = 0; ch < MBOX_CHAN_MAX; ch++)
266 chan[ch].con_priv = (void *)ch;
267
268 err = devm_mbox_controller_register(dev, &mbox->controller);
269 if (err) {
270 dev_err(dev, "Failed to register mailbox %d\n", err);
271 return err;
272 }
273
274 platform_set_drvdata(pdev, mbox);
275 dev_info(dev, "Mailbox enabled\n");
276 return 0;
277}
278
279static struct platform_driver hi3660_mbox_driver = {
280 .probe = hi3660_mbox_probe,
281 .driver = {
282 .name = "hi3660-mbox",
283 .of_match_table = hi3660_mbox_of_match,
284 },
285};
286
287static int __init hi3660_mbox_init(void)
288{
289 return platform_driver_register(&hi3660_mbox_driver);
290}
291core_initcall(hi3660_mbox_init);
292
293static void __exit hi3660_mbox_exit(void)
294{
295 platform_driver_unregister(&hi3660_mbox_driver);
296}
297module_exit(hi3660_mbox_exit);
298
299MODULE_LICENSE("GPL");
300MODULE_DESCRIPTION("Hisilicon Hi3660 Mailbox Controller");
301MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
302
