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 void __iomem *mbox_base;
44
45 /* The maximum size of buf for each channel */
46 u32 buf_size;
47
48 struct rockchip_mbox_chan chans[];
49 };
50
rockchip_mbox_send_data(struct mbox_chan * chan,void * data)51 static int rockchip_mbox_send_data(struct mbox_chan *chan, void *data)
52 {
53 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
54 struct rockchip_mbox_msg *msg = data;
55 struct rockchip_mbox_chan *chans = mb->chans;
56
57 if (!msg)
58 return -EINVAL;
59
60 if (msg->rx_size > mb->buf_size) {
61 dev_err(mb->mbox.dev, "Transmit size over buf size(%d)\n",
62 mb->buf_size);
63 return -EINVAL;
64 }
65
66 dev_dbg(mb->mbox.dev, "Chan[%d]: A2B message, cmd 0x%08x\n",
67 chans->idx, msg->cmd);
68
69 mb->chans[chans->idx].msg = msg;
70
71 writel_relaxed(msg->cmd, mb->mbox_base + MAILBOX_A2B_CMD(chans->idx));
72 writel_relaxed(msg->rx_size, mb->mbox_base +
73 MAILBOX_A2B_DAT(chans->idx));
74
75 return 0;
76 }
77
rockchip_mbox_startup(struct mbox_chan * chan)78 static int rockchip_mbox_startup(struct mbox_chan *chan)
79 {
80 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
81
82 /* Enable all B2A interrupts */
83 writel_relaxed((1 << mb->mbox.num_chans) - 1,
84 mb->mbox_base + MAILBOX_B2A_INTEN);
85
86 return 0;
87 }
88
rockchip_mbox_shutdown(struct mbox_chan * chan)89 static void rockchip_mbox_shutdown(struct mbox_chan *chan)
90 {
91 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
92 struct rockchip_mbox_chan *chans = mb->chans;
93
94 /* Disable all B2A interrupts */
95 writel_relaxed(0, mb->mbox_base + MAILBOX_B2A_INTEN);
96
97 mb->chans[chans->idx].msg = NULL;
98 }
99
100 static const struct mbox_chan_ops rockchip_mbox_chan_ops = {
101 .send_data = rockchip_mbox_send_data,
102 .startup = rockchip_mbox_startup,
103 .shutdown = rockchip_mbox_shutdown,
104 };
105
rockchip_mbox_irq(int irq,void * dev_id)106 static irqreturn_t rockchip_mbox_irq(int irq, void *dev_id)
107 {
108 int idx;
109 struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
110 u32 status = readl_relaxed(mb->mbox_base + MAILBOX_B2A_STATUS);
111
112 for (idx = 0; idx < mb->mbox.num_chans; idx++) {
113 if ((status & (1 << idx)) && (irq == mb->chans[idx].irq)) {
114 /* Clear mbox interrupt */
115 writel_relaxed(1 << idx,
116 mb->mbox_base + MAILBOX_B2A_STATUS);
117 return IRQ_WAKE_THREAD;
118 }
119 }
120
121 return IRQ_NONE;
122 }
123
rockchip_mbox_isr(int irq,void * dev_id)124 static irqreturn_t rockchip_mbox_isr(int irq, void *dev_id)
125 {
126 int idx;
127 struct rockchip_mbox_msg *msg = NULL;
128 struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
129
130 for (idx = 0; idx < mb->mbox.num_chans; idx++) {
131 if (irq != mb->chans[idx].irq)
132 continue;
133
134 msg = mb->chans[idx].msg;
135 if (!msg) {
136 dev_err(mb->mbox.dev,
137 "Chan[%d]: B2A message is NULL\n", idx);
138 break; /* spurious */
139 }
140
141 mbox_chan_received_data(&mb->mbox.chans[idx], msg);
142 mb->chans[idx].msg = NULL;
143
144 dev_dbg(mb->mbox.dev, "Chan[%d]: B2A message, cmd 0x%08x\n",
145 idx, msg->cmd);
146
147 break;
148 }
149
150 return IRQ_HANDLED;
151 }
152
153 static const struct rockchip_mbox_data rk3368_drv_data = {
154 .num_chans = 4,
155 };
156
157 static const struct of_device_id rockchip_mbox_of_match[] = {
158 { .compatible = "rockchip,rk3368-mailbox", .data = &rk3368_drv_data},
159 { },
160 };
161 MODULE_DEVICE_TABLE(of, rockchip_mbox_of_match);
162
rockchip_mbox_probe(struct platform_device * pdev)163 static int rockchip_mbox_probe(struct platform_device *pdev)
164 {
165 struct rockchip_mbox *mb;
166 const struct rockchip_mbox_data *drv_data;
167 struct resource *res;
168 struct clk *pclk;
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, struct_size(mb, chans, drv_data->num_chans), GFP_KERNEL);
177 if (!mb)
178 return -ENOMEM;
179
180 mb->mbox.chans = devm_kcalloc(&pdev->dev, drv_data->num_chans,
181 sizeof(*mb->mbox.chans), GFP_KERNEL);
182 if (!mb->mbox.chans)
183 return -ENOMEM;
184
185 platform_set_drvdata(pdev, mb);
186
187 mb->mbox.dev = &pdev->dev;
188 mb->mbox.num_chans = drv_data->num_chans;
189 mb->mbox.ops = &rockchip_mbox_chan_ops;
190 mb->mbox.txdone_irq = true;
191
192 mb->mbox_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
193 if (IS_ERR(mb->mbox_base))
194 return PTR_ERR(mb->mbox_base);
195
196 /* Each channel has two buffers for A2B and B2A */
197 mb->buf_size = (size_t)resource_size(res) / (drv_data->num_chans * 2);
198
199 pclk = devm_clk_get_enabled(&pdev->dev, "pclk_mailbox");
200 if (IS_ERR(pclk))
201 return dev_err_probe(&pdev->dev, PTR_ERR(pclk),
202 "failed to get and enable pclk_mailbox clock\n");
203
204 for (i = 0; i < mb->mbox.num_chans; i++) {
205 irq = platform_get_irq(pdev, i);
206 if (irq < 0)
207 return irq;
208
209 ret = devm_request_threaded_irq(&pdev->dev, irq,
210 rockchip_mbox_irq,
211 rockchip_mbox_isr, IRQF_ONESHOT,
212 dev_name(&pdev->dev), mb);
213 if (ret < 0)
214 return ret;
215
216 mb->chans[i].idx = i;
217 mb->chans[i].irq = irq;
218 mb->chans[i].mb = mb;
219 mb->chans[i].msg = NULL;
220 }
221
222 ret = devm_mbox_controller_register(&pdev->dev, &mb->mbox);
223 if (ret < 0)
224 dev_err(&pdev->dev, "Failed to register mailbox: %d\n", ret);
225
226 return ret;
227 }
228
229 static struct platform_driver rockchip_mbox_driver = {
230 .probe = rockchip_mbox_probe,
231 .driver = {
232 .name = "rockchip-mailbox",
233 .of_match_table = rockchip_mbox_of_match,
234 },
235 };
236
237 module_platform_driver(rockchip_mbox_driver);
238
239 MODULE_DESCRIPTION("Rockchip mailbox: communicate between CPU cores and MCU");
240 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
241 MODULE_AUTHOR("Caesar Wang <wxt@rock-chips.com>");
242