1 /*
2 * Copyright (c) 2015, Fuzhou Rockchip Electronics Co., Ltd
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 */
13
14 #include <linux/clk.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/kernel.h>
18 #include <linux/mailbox_controller.h>
19 #include <linux/module.h>
20 #include <linux/of_device.h>
21 #include <linux/platform_device.h>
22
23 #define MAILBOX_A2B_INTEN 0x00
24 #define MAILBOX_A2B_STATUS 0x04
25 #define MAILBOX_A2B_CMD(x) (0x08 + (x) * 8)
26 #define MAILBOX_A2B_DAT(x) (0x0c + (x) * 8)
27
28 #define MAILBOX_B2A_INTEN 0x28
29 #define MAILBOX_B2A_STATUS 0x2C
30 #define MAILBOX_B2A_CMD(x) (0x30 + (x) * 8)
31 #define MAILBOX_B2A_DAT(x) (0x34 + (x) * 8)
32
33 struct rockchip_mbox_msg {
34 u32 cmd;
35 int rx_size;
36 };
37
38 struct rockchip_mbox_data {
39 int num_chans;
40 };
41
42 struct rockchip_mbox_chan {
43 int idx;
44 int irq;
45 struct rockchip_mbox_msg *msg;
46 struct rockchip_mbox *mb;
47 };
48
49 struct rockchip_mbox {
50 struct mbox_controller mbox;
51 struct clk *pclk;
52 void __iomem *mbox_base;
53
54 /* The maximum size of buf for each channel */
55 u32 buf_size;
56
57 struct rockchip_mbox_chan *chans;
58 };
59
rockchip_mbox_send_data(struct mbox_chan * chan,void * data)60 static int rockchip_mbox_send_data(struct mbox_chan *chan, void *data)
61 {
62 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
63 struct rockchip_mbox_msg *msg = data;
64 struct rockchip_mbox_chan *chans = mb->chans;
65
66 if (!msg)
67 return -EINVAL;
68
69 if (msg->rx_size > mb->buf_size) {
70 dev_err(mb->mbox.dev, "Transmit size over buf size(%d)\n",
71 mb->buf_size);
72 return -EINVAL;
73 }
74
75 dev_dbg(mb->mbox.dev, "Chan[%d]: A2B message, cmd 0x%08x\n",
76 chans->idx, msg->cmd);
77
78 mb->chans[chans->idx].msg = msg;
79
80 writel_relaxed(msg->cmd, mb->mbox_base + MAILBOX_A2B_CMD(chans->idx));
81 writel_relaxed(msg->rx_size, mb->mbox_base +
82 MAILBOX_A2B_DAT(chans->idx));
83
84 return 0;
85 }
86
rockchip_mbox_startup(struct mbox_chan * chan)87 static int rockchip_mbox_startup(struct mbox_chan *chan)
88 {
89 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
90
91 /* Enable all B2A interrupts */
92 writel_relaxed((1 << mb->mbox.num_chans) - 1,
93 mb->mbox_base + MAILBOX_B2A_INTEN);
94
95 return 0;
96 }
97
rockchip_mbox_shutdown(struct mbox_chan * chan)98 static void rockchip_mbox_shutdown(struct mbox_chan *chan)
99 {
100 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
101 struct rockchip_mbox_chan *chans = mb->chans;
102
103 /* Disable all B2A interrupts */
104 writel_relaxed(0, mb->mbox_base + MAILBOX_B2A_INTEN);
105
106 mb->chans[chans->idx].msg = NULL;
107 }
108
109 static const struct mbox_chan_ops rockchip_mbox_chan_ops = {
110 .send_data = rockchip_mbox_send_data,
111 .startup = rockchip_mbox_startup,
112 .shutdown = rockchip_mbox_shutdown,
113 };
114
rockchip_mbox_irq(int irq,void * dev_id)115 static irqreturn_t rockchip_mbox_irq(int irq, void *dev_id)
116 {
117 int idx;
118 struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
119 u32 status = readl_relaxed(mb->mbox_base + MAILBOX_B2A_STATUS);
120
121 for (idx = 0; idx < mb->mbox.num_chans; idx++) {
122 if ((status & (1 << idx)) && (irq == mb->chans[idx].irq)) {
123 /* Clear mbox interrupt */
124 writel_relaxed(1 << idx,
125 mb->mbox_base + MAILBOX_B2A_STATUS);
126 return IRQ_WAKE_THREAD;
127 }
128 }
129
130 return IRQ_NONE;
131 }
132
rockchip_mbox_isr(int irq,void * dev_id)133 static irqreturn_t rockchip_mbox_isr(int irq, void *dev_id)
134 {
135 int idx;
136 struct rockchip_mbox_msg *msg = NULL;
137 struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
138
139 for (idx = 0; idx < mb->mbox.num_chans; idx++) {
140 if (irq != mb->chans[idx].irq)
141 continue;
142
143 msg = mb->chans[idx].msg;
144 if (!msg) {
145 dev_err(mb->mbox.dev,
146 "Chan[%d]: B2A message is NULL\n", idx);
147 break; /* spurious */
148 }
149
150 mbox_chan_received_data(&mb->mbox.chans[idx], msg);
151 mb->chans[idx].msg = NULL;
152
153 dev_dbg(mb->mbox.dev, "Chan[%d]: B2A message, cmd 0x%08x\n",
154 idx, msg->cmd);
155
156 break;
157 }
158
159 return IRQ_HANDLED;
160 }
161
162 static const struct rockchip_mbox_data rk3368_drv_data = {
163 .num_chans = 4,
164 };
165
166 static const struct of_device_id rockchip_mbox_of_match[] = {
167 { .compatible = "rockchip,rk3368-mailbox", .data = &rk3368_drv_data},
168 { },
169 };
170 MODULE_DEVICE_TABLE(of, rockchp_mbox_of_match);
171
rockchip_mbox_probe(struct platform_device * pdev)172 static int rockchip_mbox_probe(struct platform_device *pdev)
173 {
174 struct rockchip_mbox *mb;
175 const struct of_device_id *match;
176 const struct rockchip_mbox_data *drv_data;
177 struct resource *res;
178 int ret, irq, i;
179
180 if (!pdev->dev.of_node)
181 return -ENODEV;
182
183 match = of_match_node(rockchip_mbox_of_match, pdev->dev.of_node);
184 drv_data = (const struct rockchip_mbox_data *)match->data;
185
186 mb = devm_kzalloc(&pdev->dev, sizeof(*mb), GFP_KERNEL);
187 if (!mb)
188 return -ENOMEM;
189
190 mb->chans = devm_kcalloc(&pdev->dev, drv_data->num_chans,
191 sizeof(*mb->chans), GFP_KERNEL);
192 if (!mb->chans)
193 return -ENOMEM;
194
195 mb->mbox.chans = devm_kcalloc(&pdev->dev, drv_data->num_chans,
196 sizeof(*mb->mbox.chans), GFP_KERNEL);
197 if (!mb->mbox.chans)
198 return -ENOMEM;
199
200 platform_set_drvdata(pdev, mb);
201
202 mb->mbox.dev = &pdev->dev;
203 mb->mbox.num_chans = drv_data->num_chans;
204 mb->mbox.ops = &rockchip_mbox_chan_ops;
205 mb->mbox.txdone_irq = true;
206
207 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
208 if (!res)
209 return -ENODEV;
210
211 mb->mbox_base = devm_ioremap_resource(&pdev->dev, res);
212 if (IS_ERR(mb->mbox_base))
213 return PTR_ERR(mb->mbox_base);
214
215 /* Each channel has two buffers for A2B and B2A */
216 mb->buf_size = (size_t)resource_size(res) / (drv_data->num_chans * 2);
217
218 mb->pclk = devm_clk_get(&pdev->dev, "pclk_mailbox");
219 if (IS_ERR(mb->pclk)) {
220 ret = PTR_ERR(mb->pclk);
221 dev_err(&pdev->dev, "failed to get pclk_mailbox clock: %d\n",
222 ret);
223 return ret;
224 }
225
226 ret = clk_prepare_enable(mb->pclk);
227 if (ret) {
228 dev_err(&pdev->dev, "failed to enable pclk: %d\n", ret);
229 return ret;
230 }
231
232 for (i = 0; i < mb->mbox.num_chans; i++) {
233 irq = platform_get_irq(pdev, i);
234 if (irq < 0)
235 return irq;
236
237 ret = devm_request_threaded_irq(&pdev->dev, irq,
238 rockchip_mbox_irq,
239 rockchip_mbox_isr, IRQF_ONESHOT,
240 dev_name(&pdev->dev), mb);
241 if (ret < 0)
242 return ret;
243
244 mb->chans[i].idx = i;
245 mb->chans[i].irq = irq;
246 mb->chans[i].mb = mb;
247 mb->chans[i].msg = NULL;
248 }
249
250 ret = mbox_controller_register(&mb->mbox);
251 if (ret < 0)
252 dev_err(&pdev->dev, "Failed to register mailbox: %d\n", ret);
253
254 return ret;
255 }
256
rockchip_mbox_remove(struct platform_device * pdev)257 static int rockchip_mbox_remove(struct platform_device *pdev)
258 {
259 struct rockchip_mbox *mb = platform_get_drvdata(pdev);
260
261 if (!mb)
262 return -EINVAL;
263
264 mbox_controller_unregister(&mb->mbox);
265
266 return 0;
267 }
268
269 static struct platform_driver rockchip_mbox_driver = {
270 .probe = rockchip_mbox_probe,
271 .remove = rockchip_mbox_remove,
272 .driver = {
273 .name = "rockchip-mailbox",
274 .of_match_table = of_match_ptr(rockchip_mbox_of_match),
275 },
276 };
277
278 module_platform_driver(rockchip_mbox_driver);
279
280 MODULE_LICENSE("GPL v2");
281 MODULE_DESCRIPTION("Rockchip mailbox: communicate between CPU cores and MCU");
282 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
283 MODULE_AUTHOR("Caesar Wang <wxt@rock-chips.com>");
284
