1 /*
2  * OMAP Remote Processor driver
3  *
4  * Copyright (C) 2011 Texas Instruments, Inc.
5  * Copyright (C) 2011 Google, Inc.
6  *
7  * Ohad Ben-Cohen <ohad@wizery.com>
8  * Brian Swetland <swetland@google.com>
9  * Fernando Guzman Lugo <fernando.lugo@ti.com>
10  * Mark Grosen <mgrosen@ti.com>
11  * Suman Anna <s-anna@ti.com>
12  * Hari Kanigeri <h-kanigeri2@ti.com>
13  *
14  * This program is free software; you can redistribute it and/or
15  * modify it under the terms of the GNU General Public License
16  * version 2 as published by the Free Software Foundation.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  */
23 
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/err.h>
27 #include <linux/platform_device.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/remoteproc.h>
30 
31 #include <plat/mailbox.h>
32 #include <plat/remoteproc.h>
33 
34 #include "omap_remoteproc.h"
35 #include "remoteproc_internal.h"
36 
37 /**
38  * struct omap_rproc - omap remote processor state
39  * @mbox: omap mailbox handle
40  * @nb: notifier block that will be invoked on inbound mailbox messages
41  * @rproc: rproc handle
42  */
43 struct omap_rproc {
44 	struct omap_mbox *mbox;
45 	struct notifier_block nb;
46 	struct rproc *rproc;
47 };
48 
49 /**
50  * omap_rproc_mbox_callback() - inbound mailbox message handler
51  * @this: notifier block
52  * @index: unused
53  * @data: mailbox payload
54  *
55  * This handler is invoked by omap's mailbox driver whenever a mailbox
56  * message is received. Usually, the mailbox payload simply contains
57  * the index of the virtqueue that is kicked by the remote processor,
58  * and we let remoteproc core handle it.
59  *
60  * In addition to virtqueue indices, we also have some out-of-band values
61  * that indicates different events. Those values are deliberately very
62  * big so they don't coincide with virtqueue indices.
63  */
64 static int omap_rproc_mbox_callback(struct notifier_block *this,
65 					unsigned long index, void *data)
66 {
67 	mbox_msg_t msg = (mbox_msg_t) data;
68 	struct omap_rproc *oproc = container_of(this, struct omap_rproc, nb);
69 	struct device *dev = oproc->rproc->dev.parent;
70 	const char *name = oproc->rproc->name;
71 
72 	dev_dbg(dev, "mbox msg: 0x%x\n", msg);
73 
74 	switch (msg) {
75 	case RP_MBOX_CRASH:
76 		/* just log this for now. later, we'll also do recovery */
77 		dev_err(dev, "omap rproc %s crashed\n", name);
78 		break;
79 	case RP_MBOX_ECHO_REPLY:
80 		dev_info(dev, "received echo reply from %s\n", name);
81 		break;
82 	default:
83 		/* msg contains the index of the triggered vring */
84 		if (rproc_vq_interrupt(oproc->rproc, msg) == IRQ_NONE)
85 			dev_dbg(dev, "no message was found in vqid %d\n", msg);
86 	}
87 
88 	return NOTIFY_DONE;
89 }
90 
91 /* kick a virtqueue */
92 static void omap_rproc_kick(struct rproc *rproc, int vqid)
93 {
94 	struct omap_rproc *oproc = rproc->priv;
95 	struct device *dev = rproc->dev.parent;
96 	int ret;
97 
98 	/* send the index of the triggered virtqueue in the mailbox payload */
99 	ret = omap_mbox_msg_send(oproc->mbox, vqid);
100 	if (ret)
101 		dev_err(dev, "omap_mbox_msg_send failed: %d\n", ret);
102 }
103 
104 /*
105  * Power up the remote processor.
106  *
107  * This function will be invoked only after the firmware for this rproc
108  * was loaded, parsed successfully, and all of its resource requirements
109  * were met.
110  */
111 static int omap_rproc_start(struct rproc *rproc)
112 {
113 	struct omap_rproc *oproc = rproc->priv;
114 	struct device *dev = rproc->dev.parent;
115 	struct platform_device *pdev = to_platform_device(dev);
116 	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
117 	int ret;
118 
119 	oproc->nb.notifier_call = omap_rproc_mbox_callback;
120 
121 	/* every omap rproc is assigned a mailbox instance for messaging */
122 	oproc->mbox = omap_mbox_get(pdata->mbox_name, &oproc->nb);
123 	if (IS_ERR(oproc->mbox)) {
124 		ret = PTR_ERR(oproc->mbox);
125 		dev_err(dev, "omap_mbox_get failed: %d\n", ret);
126 		return ret;
127 	}
128 
129 	/*
130 	 * Ping the remote processor. this is only for sanity-sake;
131 	 * there is no functional effect whatsoever.
132 	 *
133 	 * Note that the reply will _not_ arrive immediately: this message
134 	 * will wait in the mailbox fifo until the remote processor is booted.
135 	 */
136 	ret = omap_mbox_msg_send(oproc->mbox, RP_MBOX_ECHO_REQUEST);
137 	if (ret) {
138 		dev_err(dev, "omap_mbox_get failed: %d\n", ret);
139 		goto put_mbox;
140 	}
141 
142 	ret = pdata->device_enable(pdev);
143 	if (ret) {
144 		dev_err(dev, "omap_device_enable failed: %d\n", ret);
145 		goto put_mbox;
146 	}
147 
148 	return 0;
149 
150 put_mbox:
151 	omap_mbox_put(oproc->mbox, &oproc->nb);
152 	return ret;
153 }
154 
155 /* power off the remote processor */
156 static int omap_rproc_stop(struct rproc *rproc)
157 {
158 	struct device *dev = rproc->dev.parent;
159 	struct platform_device *pdev = to_platform_device(dev);
160 	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
161 	struct omap_rproc *oproc = rproc->priv;
162 	int ret;
163 
164 	ret = pdata->device_shutdown(pdev);
165 	if (ret)
166 		return ret;
167 
168 	omap_mbox_put(oproc->mbox, &oproc->nb);
169 
170 	return 0;
171 }
172 
173 static struct rproc_ops omap_rproc_ops = {
174 	.start		= omap_rproc_start,
175 	.stop		= omap_rproc_stop,
176 	.kick		= omap_rproc_kick,
177 };
178 
179 static int __devinit omap_rproc_probe(struct platform_device *pdev)
180 {
181 	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
182 	struct omap_rproc *oproc;
183 	struct rproc *rproc;
184 	int ret;
185 
186 	ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
187 	if (ret) {
188 		dev_err(&pdev->dev, "dma_set_coherent_mask: %d\n", ret);
189 		return ret;
190 	}
191 
192 	rproc = rproc_alloc(&pdev->dev, pdata->name, &omap_rproc_ops,
193 				pdata->firmware, sizeof(*oproc));
194 	if (!rproc)
195 		return -ENOMEM;
196 
197 	oproc = rproc->priv;
198 	oproc->rproc = rproc;
199 
200 	platform_set_drvdata(pdev, rproc);
201 
202 	ret = rproc_add(rproc);
203 	if (ret)
204 		goto free_rproc;
205 
206 	return 0;
207 
208 free_rproc:
209 	rproc_put(rproc);
210 	return ret;
211 }
212 
213 static int __devexit omap_rproc_remove(struct platform_device *pdev)
214 {
215 	struct rproc *rproc = platform_get_drvdata(pdev);
216 
217 	rproc_del(rproc);
218 	rproc_put(rproc);
219 
220 	return 0;
221 }
222 
223 static struct platform_driver omap_rproc_driver = {
224 	.probe = omap_rproc_probe,
225 	.remove = __devexit_p(omap_rproc_remove),
226 	.driver = {
227 		.name = "omap-rproc",
228 		.owner = THIS_MODULE,
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