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
25struct rockchip_mbox_msg {
26	u32 cmd;
27	int rx_size;
28};
29
30struct rockchip_mbox_data {
31	int num_chans;
32};
33
34struct rockchip_mbox_chan {
35	int idx;
36	int irq;
37	struct rockchip_mbox_msg *msg;
38	struct rockchip_mbox *mb;
39};
40
41struct 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
52static 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
79static 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
90static 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
101static 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
107static 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
125static 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
154static const struct rockchip_mbox_data rk3368_drv_data = {
155	.num_chans = 4,
156};
157
158static const struct of_device_id rockchip_mbox_of_match[] = {
159	{ .compatible = "rockchip,rk3368-mailbox", .data = &rk3368_drv_data},
160	{ },
161};
162MODULE_DEVICE_TABLE(of, rockchp_mbox_of_match);
163
164static 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
243static 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
251module_platform_driver(rockchip_mbox_driver);
252
253MODULE_DESCRIPTION("Rockchip mailbox: communicate between CPU cores and MCU");
254MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
255MODULE_AUTHOR("Caesar Wang <wxt@rock-chips.com>");
256