1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2015, Fuzhou Rockchip Electronics Co., Ltd
4 */
5
6 #include <linux/clk.h>
7 #include <linux/interrupt.h>
8 #include <linux/io.h>
9 #include <linux/kernel.h>
10 #include <linux/mailbox_controller.h>
11 #include <linux/of.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14
15 #define MAILBOX_A2B_INTEN 0x00
16 #define MAILBOX_A2B_STATUS 0x04
17 #define MAILBOX_A2B_CMD(x) (0x08 + (x) * 8)
18 #define MAILBOX_A2B_DAT(x) (0x0c + (x) * 8)
19
20 #define MAILBOX_B2A_INTEN 0x28
21 #define MAILBOX_B2A_STATUS 0x2C
22 #define MAILBOX_B2A_CMD(x) (0x30 + (x) * 8)
23 #define MAILBOX_B2A_DAT(x) (0x34 + (x) * 8)
24
25 struct rockchip_mbox_msg {
26 u32 cmd;
27 int rx_size;
28 };
29
30 struct rockchip_mbox_data {
31 int num_chans;
32 };
33
34 struct rockchip_mbox_chan {
35 int idx;
36 int irq;
37 struct rockchip_mbox_msg *msg;
38 struct rockchip_mbox *mb;
39 };
40
41 struct rockchip_mbox {
42 struct mbox_controller mbox;
43 struct clk *pclk;
44 void __iomem *mbox_base;
45
46 /* The maximum size of buf for each channel */
47 u32 buf_size;
48
49 struct rockchip_mbox_chan *chans;
50 };
51
rockchip_mbox_send_data(struct mbox_chan * chan,void * data)52 static int rockchip_mbox_send_data(struct mbox_chan *chan, void *data)
53 {
54 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
55 struct rockchip_mbox_msg *msg = data;
56 struct rockchip_mbox_chan *chans = mb->chans;
57
58 if (!msg)
59 return -EINVAL;
60
61 if (msg->rx_size > mb->buf_size) {
62 dev_err(mb->mbox.dev, "Transmit size over buf size(%d)\n",
63 mb->buf_size);
64 return -EINVAL;
65 }
66
67 dev_dbg(mb->mbox.dev, "Chan[%d]: A2B message, cmd 0x%08x\n",
68 chans->idx, msg->cmd);
69
70 mb->chans[chans->idx].msg = msg;
71
72 writel_relaxed(msg->cmd, mb->mbox_base + MAILBOX_A2B_CMD(chans->idx));
73 writel_relaxed(msg->rx_size, mb->mbox_base +
74 MAILBOX_A2B_DAT(chans->idx));
75
76 return 0;
77 }
78
rockchip_mbox_startup(struct mbox_chan * chan)79 static int rockchip_mbox_startup(struct mbox_chan *chan)
80 {
81 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
82
83 /* Enable all B2A interrupts */
84 writel_relaxed((1 << mb->mbox.num_chans) - 1,
85 mb->mbox_base + MAILBOX_B2A_INTEN);
86
87 return 0;
88 }
89
rockchip_mbox_shutdown(struct mbox_chan * chan)90 static void rockchip_mbox_shutdown(struct mbox_chan *chan)
91 {
92 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
93 struct rockchip_mbox_chan *chans = mb->chans;
94
95 /* Disable all B2A interrupts */
96 writel_relaxed(0, mb->mbox_base + MAILBOX_B2A_INTEN);
97
98 mb->chans[chans->idx].msg = NULL;
99 }
100
101 static const struct mbox_chan_ops rockchip_mbox_chan_ops = {
102 .send_data = rockchip_mbox_send_data,
103 .startup = rockchip_mbox_startup,
104 .shutdown = rockchip_mbox_shutdown,
105 };
106
rockchip_mbox_irq(int irq,void * dev_id)107 static irqreturn_t rockchip_mbox_irq(int irq, void *dev_id)
108 {
109 int idx;
110 struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
111 u32 status = readl_relaxed(mb->mbox_base + MAILBOX_B2A_STATUS);
112
113 for (idx = 0; idx < mb->mbox.num_chans; idx++) {
114 if ((status & (1 << idx)) && (irq == mb->chans[idx].irq)) {
115 /* Clear mbox interrupt */
116 writel_relaxed(1 << idx,
117 mb->mbox_base + MAILBOX_B2A_STATUS);
118 return IRQ_WAKE_THREAD;
119 }
120 }
121
122 return IRQ_NONE;
123 }
124
rockchip_mbox_isr(int irq,void * dev_id)125 static irqreturn_t rockchip_mbox_isr(int irq, void *dev_id)
126 {
127 int idx;
128 struct rockchip_mbox_msg *msg = NULL;
129 struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
130
131 for (idx = 0; idx < mb->mbox.num_chans; idx++) {
132 if (irq != mb->chans[idx].irq)
133 continue;
134
135 msg = mb->chans[idx].msg;
136 if (!msg) {
137 dev_err(mb->mbox.dev,
138 "Chan[%d]: B2A message is NULL\n", idx);
139 break; /* spurious */
140 }
141
142 mbox_chan_received_data(&mb->mbox.chans[idx], msg);
143 mb->chans[idx].msg = NULL;
144
145 dev_dbg(mb->mbox.dev, "Chan[%d]: B2A message, cmd 0x%08x\n",
146 idx, msg->cmd);
147
148 break;
149 }
150
151 return IRQ_HANDLED;
152 }
153
154 static const struct rockchip_mbox_data rk3368_drv_data = {
155 .num_chans = 4,
156 };
157
158 static const struct of_device_id rockchip_mbox_of_match[] = {
159 { .compatible = "rockchip,rk3368-mailbox", .data = &rk3368_drv_data},
160 { },
161 };
162 MODULE_DEVICE_TABLE(of, rockchip_mbox_of_match);
163
rockchip_mbox_probe(struct platform_device * pdev)164 static int rockchip_mbox_probe(struct platform_device *pdev)
165 {
166 struct rockchip_mbox *mb;
167 const struct rockchip_mbox_data *drv_data;
168 struct resource *res;
169 int ret, irq, i;
170
171 if (!pdev->dev.of_node)
172 return -ENODEV;
173
174 drv_data = (const struct rockchip_mbox_data *) device_get_match_data(&pdev->dev);
175
176 mb = devm_kzalloc(&pdev->dev, sizeof(*mb), GFP_KERNEL);
177 if (!mb)
178 return -ENOMEM;
179
180 mb->chans = devm_kcalloc(&pdev->dev, drv_data->num_chans,
181 sizeof(*mb->chans), GFP_KERNEL);
182 if (!mb->chans)
183 return -ENOMEM;
184
185 mb->mbox.chans = devm_kcalloc(&pdev->dev, drv_data->num_chans,
186 sizeof(*mb->mbox.chans), GFP_KERNEL);
187 if (!mb->mbox.chans)
188 return -ENOMEM;
189
190 platform_set_drvdata(pdev, mb);
191
192 mb->mbox.dev = &pdev->dev;
193 mb->mbox.num_chans = drv_data->num_chans;
194 mb->mbox.ops = &rockchip_mbox_chan_ops;
195 mb->mbox.txdone_irq = true;
196
197 mb->mbox_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
198 if (IS_ERR(mb->mbox_base))
199 return PTR_ERR(mb->mbox_base);
200
201 /* Each channel has two buffers for A2B and B2A */
202 mb->buf_size = (size_t)resource_size(res) / (drv_data->num_chans * 2);
203
204 mb->pclk = devm_clk_get(&pdev->dev, "pclk_mailbox");
205 if (IS_ERR(mb->pclk)) {
206 ret = PTR_ERR(mb->pclk);
207 dev_err(&pdev->dev, "failed to get pclk_mailbox clock: %d\n",
208 ret);
209 return ret;
210 }
211
212 ret = clk_prepare_enable(mb->pclk);
213 if (ret) {
214 dev_err(&pdev->dev, "failed to enable pclk: %d\n", ret);
215 return ret;
216 }
217
218 for (i = 0; i < mb->mbox.num_chans; i++) {
219 irq = platform_get_irq(pdev, i);
220 if (irq < 0)
221 return irq;
222
223 ret = devm_request_threaded_irq(&pdev->dev, irq,
224 rockchip_mbox_irq,
225 rockchip_mbox_isr, IRQF_ONESHOT,
226 dev_name(&pdev->dev), mb);
227 if (ret < 0)
228 return ret;
229
230 mb->chans[i].idx = i;
231 mb->chans[i].irq = irq;
232 mb->chans[i].mb = mb;
233 mb->chans[i].msg = NULL;
234 }
235
236 ret = devm_mbox_controller_register(&pdev->dev, &mb->mbox);
237 if (ret < 0)
238 dev_err(&pdev->dev, "Failed to register mailbox: %d\n", ret);
239
240 return ret;
241 }
242
243 static struct platform_driver rockchip_mbox_driver = {
244 .probe = rockchip_mbox_probe,
245 .driver = {
246 .name = "rockchip-mailbox",
247 .of_match_table = rockchip_mbox_of_match,
248 },
249 };
250
251 module_platform_driver(rockchip_mbox_driver);
252
253 MODULE_DESCRIPTION("Rockchip mailbox: communicate between CPU cores and MCU");
254 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
255 MODULE_AUTHOR("Caesar Wang <wxt@rock-chips.com>");
256