1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP Remote Processor driver
4  *
5  * Copyright (C) 2011 Texas Instruments, Inc.
6  * Copyright (C) 2011 Google, Inc.
7  *
8  * Ohad Ben-Cohen <ohad@wizery.com>
9  * Brian Swetland <swetland@google.com>
10  * Fernando Guzman Lugo <fernando.lugo@ti.com>
11  * Mark Grosen <mgrosen@ti.com>
12  * Suman Anna <s-anna@ti.com>
13  * Hari Kanigeri <h-kanigeri2@ti.com>
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/err.h>
19 #include <linux/platform_device.h>
20 #include <linux/dma-mapping.h>
21 #include <linux/remoteproc.h>
22 #include <linux/mailbox_client.h>
23 #include <linux/omap-mailbox.h>
24 
25 #include <linux/platform_data/remoteproc-omap.h>
26 
27 #include "omap_remoteproc.h"
28 #include "remoteproc_internal.h"
29 
30 /**
31  * struct omap_rproc - omap remote processor state
32  * @mbox: mailbox channel handle
33  * @client: mailbox client to request the mailbox channel
34  * @rproc: rproc handle
35  */
36 struct omap_rproc {
37 	struct mbox_chan *mbox;
38 	struct mbox_client client;
39 	struct rproc *rproc;
40 };
41 
42 /**
43  * omap_rproc_mbox_callback() - inbound mailbox message handler
44  * @client: mailbox client pointer used for requesting the mailbox channel
45  * @data: mailbox payload
46  *
47  * This handler is invoked by omap's mailbox driver whenever a mailbox
48  * message is received. Usually, the mailbox payload simply contains
49  * the index of the virtqueue that is kicked by the remote processor,
50  * and we let remoteproc core handle it.
51  *
52  * In addition to virtqueue indices, we also have some out-of-band values
53  * that indicates different events. Those values are deliberately very
54  * big so they don't coincide with virtqueue indices.
55  */
56 static void omap_rproc_mbox_callback(struct mbox_client *client, void *data)
57 {
58 	struct omap_rproc *oproc = container_of(client, struct omap_rproc,
59 						client);
60 	struct device *dev = oproc->rproc->dev.parent;
61 	const char *name = oproc->rproc->name;
62 	u32 msg = (u32)data;
63 
64 	dev_dbg(dev, "mbox msg: 0x%x\n", msg);
65 
66 	switch (msg) {
67 	case RP_MBOX_CRASH:
68 		/* just log this for now. later, we'll also do recovery */
69 		dev_err(dev, "omap rproc %s crashed\n", name);
70 		break;
71 	case RP_MBOX_ECHO_REPLY:
72 		dev_info(dev, "received echo reply from %s\n", name);
73 		break;
74 	default:
75 		/* msg contains the index of the triggered vring */
76 		if (rproc_vq_interrupt(oproc->rproc, msg) == IRQ_NONE)
77 			dev_dbg(dev, "no message was found in vqid %d\n", msg);
78 	}
79 }
80 
81 /* kick a virtqueue */
82 static void omap_rproc_kick(struct rproc *rproc, int vqid)
83 {
84 	struct omap_rproc *oproc = rproc->priv;
85 	struct device *dev = rproc->dev.parent;
86 	int ret;
87 
88 	/* send the index of the triggered virtqueue in the mailbox payload */
89 	ret = mbox_send_message(oproc->mbox, (void *)vqid);
90 	if (ret < 0)
91 		dev_err(dev, "failed to send mailbox message, status = %d\n",
92 			ret);
93 }
94 
95 /*
96  * Power up the remote processor.
97  *
98  * This function will be invoked only after the firmware for this rproc
99  * was loaded, parsed successfully, and all of its resource requirements
100  * were met.
101  */
102 static int omap_rproc_start(struct rproc *rproc)
103 {
104 	struct omap_rproc *oproc = rproc->priv;
105 	struct device *dev = rproc->dev.parent;
106 	struct platform_device *pdev = to_platform_device(dev);
107 	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
108 	int ret;
109 	struct mbox_client *client = &oproc->client;
110 
111 	if (pdata->set_bootaddr)
112 		pdata->set_bootaddr(rproc->bootaddr);
113 
114 	client->dev = dev;
115 	client->tx_done = NULL;
116 	client->rx_callback = omap_rproc_mbox_callback;
117 	client->tx_block = false;
118 	client->knows_txdone = false;
119 
120 	oproc->mbox = omap_mbox_request_channel(client, pdata->mbox_name);
121 	if (IS_ERR(oproc->mbox)) {
122 		ret = -EBUSY;
123 		dev_err(dev, "mbox_request_channel failed: %ld\n",
124 			PTR_ERR(oproc->mbox));
125 		return ret;
126 	}
127 
128 	/*
129 	 * Ping the remote processor. this is only for sanity-sake;
130 	 * there is no functional effect whatsoever.
131 	 *
132 	 * Note that the reply will _not_ arrive immediately: this message
133 	 * will wait in the mailbox fifo until the remote processor is booted.
134 	 */
135 	ret = mbox_send_message(oproc->mbox, (void *)RP_MBOX_ECHO_REQUEST);
136 	if (ret < 0) {
137 		dev_err(dev, "mbox_send_message failed: %d\n", ret);
138 		goto put_mbox;
139 	}
140 
141 	ret = pdata->device_enable(pdev);
142 	if (ret) {
143 		dev_err(dev, "omap_device_enable failed: %d\n", ret);
144 		goto put_mbox;
145 	}
146 
147 	return 0;
148 
149 put_mbox:
150 	mbox_free_channel(oproc->mbox);
151 	return ret;
152 }
153 
154 /* power off the remote processor */
155 static int omap_rproc_stop(struct rproc *rproc)
156 {
157 	struct device *dev = rproc->dev.parent;
158 	struct platform_device *pdev = to_platform_device(dev);
159 	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
160 	struct omap_rproc *oproc = rproc->priv;
161 	int ret;
162 
163 	ret = pdata->device_shutdown(pdev);
164 	if (ret)
165 		return ret;
166 
167 	mbox_free_channel(oproc->mbox);
168 
169 	return 0;
170 }
171 
172 static const struct rproc_ops omap_rproc_ops = {
173 	.start		= omap_rproc_start,
174 	.stop		= omap_rproc_stop,
175 	.kick		= omap_rproc_kick,
176 };
177 
178 static int omap_rproc_probe(struct platform_device *pdev)
179 {
180 	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
181 	struct omap_rproc *oproc;
182 	struct rproc *rproc;
183 	int ret;
184 
185 	ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
186 	if (ret) {
187 		dev_err(&pdev->dev, "dma_set_coherent_mask: %d\n", ret);
188 		return ret;
189 	}
190 
191 	rproc = rproc_alloc(&pdev->dev, pdata->name, &omap_rproc_ops,
192 			    pdata->firmware, sizeof(*oproc));
193 	if (!rproc)
194 		return -ENOMEM;
195 
196 	oproc = rproc->priv;
197 	oproc->rproc = rproc;
198 	/* All existing OMAP IPU and DSP processors have an MMU */
199 	rproc->has_iommu = true;
200 
201 	platform_set_drvdata(pdev, rproc);
202 
203 	ret = rproc_add(rproc);
204 	if (ret)
205 		goto free_rproc;
206 
207 	return 0;
208 
209 free_rproc:
210 	rproc_free(rproc);
211 	return ret;
212 }
213 
214 static int omap_rproc_remove(struct platform_device *pdev)
215 {
216 	struct rproc *rproc = platform_get_drvdata(pdev);
217 
218 	rproc_del(rproc);
219 	rproc_free(rproc);
220 
221 	return 0;
222 }
223 
224 static struct platform_driver omap_rproc_driver = {
225 	.probe = omap_rproc_probe,
226 	.remove = omap_rproc_remove,
227 	.driver = {
228 		.name = "omap-rproc",
229 	},
230 };
231 
232 module_platform_driver(omap_rproc_driver);
233 
234 MODULE_LICENSE("GPL v2");
235 MODULE_DESCRIPTION("OMAP Remote Processor control driver");
236