1 /*
2  * Copyright (C) ST-Ericsson AB 2012
3  * Author: Sjur Brændeland <sjur.brandeland@stericsson.com>
4  * License terms:  GNU General Public License (GPL), version 2
5  */
6 
7 #include <linux/module.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/remoteproc.h>
10 #include <linux/ste_modem_shm.h>
11 #include "remoteproc_internal.h"
12 
13 #define SPROC_FW_SIZE (50 * 4096)
14 #define SPROC_MAX_TOC_ENTRIES 32
15 #define SPROC_MAX_NOTIFY_ID 14
16 #define SPROC_RESOURCE_NAME "rsc-table"
17 #define SPROC_MODEM_NAME "ste-modem"
18 #define SPROC_MODEM_FIRMWARE SPROC_MODEM_NAME "-fw.bin"
19 
20 #define sproc_dbg(sproc, fmt, ...) \
21 	dev_dbg(&sproc->mdev->pdev.dev, fmt, ##__VA_ARGS__)
22 #define sproc_err(sproc, fmt, ...) \
23 	dev_err(&sproc->mdev->pdev.dev, fmt, ##__VA_ARGS__)
24 
25 /* STE-modem control structure */
26 struct sproc {
27 	struct rproc *rproc;
28 	struct ste_modem_device *mdev;
29 	int error;
30 	void *fw_addr;
31 	size_t fw_size;
32 	dma_addr_t fw_dma_addr;
33 };
34 
35 /* STE-Modem firmware entry */
36 struct ste_toc_entry {
37 	__le32 start;
38 	__le32 size;
39 	__le32 flags;
40 	__le32 entry_point;
41 	__le32 load_addr;
42 	char name[12];
43 };
44 
45 /*
46  * The Table Of Content is located at the start of the firmware image and
47  * at offset zero in the shared memory region. The resource table typically
48  * contains the initial boot image (boot strap) and other information elements
49  * such as remoteproc resource table. Each entry is identified by a unique
50  * name.
51  */
52 struct ste_toc {
53 	struct ste_toc_entry table[SPROC_MAX_TOC_ENTRIES];
54 };
55 
56 /* Loads the firmware to shared memory. */
sproc_load_segments(struct rproc * rproc,const struct firmware * fw)57 static int sproc_load_segments(struct rproc *rproc, const struct firmware *fw)
58 {
59 	struct sproc *sproc = rproc->priv;
60 
61 	memcpy(sproc->fw_addr, fw->data, fw->size);
62 
63 	return 0;
64 }
65 
66 /* Find the entry for resource table in the Table of Content */
sproc_find_rsc_entry(const void * data)67 static const struct ste_toc_entry *sproc_find_rsc_entry(const void *data)
68 {
69 	int i;
70 	const struct ste_toc *toc = data;
71 
72 	/* Search the table for the resource table */
73 	for (i = 0; i < SPROC_MAX_TOC_ENTRIES &&
74 		    toc->table[i].start != 0xffffffff; i++) {
75 		if (!strncmp(toc->table[i].name, SPROC_RESOURCE_NAME,
76 			     sizeof(toc->table[i].name)))
77 			return &toc->table[i];
78 	}
79 
80 	return NULL;
81 }
82 
83 /* Find the resource table inside the remote processor's firmware. */
84 static struct resource_table *
sproc_find_rsc_table(struct rproc * rproc,const struct firmware * fw,int * tablesz)85 sproc_find_rsc_table(struct rproc *rproc, const struct firmware *fw,
86 		     int *tablesz)
87 {
88 	struct sproc *sproc = rproc->priv;
89 	struct resource_table *table;
90 	const struct ste_toc_entry *entry;
91 
92 	if (!fw)
93 		return NULL;
94 
95 	entry = sproc_find_rsc_entry(fw->data);
96 	if (!entry) {
97 		sproc_err(sproc, "resource table not found in fw\n");
98 		return NULL;
99 	}
100 
101 	table = (void *)(fw->data + entry->start);
102 
103 	/* sanity check size and offset of resource table */
104 	if (entry->start > SPROC_FW_SIZE ||
105 	    entry->size > SPROC_FW_SIZE ||
106 	    fw->size > SPROC_FW_SIZE ||
107 	    entry->start + entry->size > fw->size ||
108 	    sizeof(struct resource_table) > entry->size) {
109 		sproc_err(sproc, "bad size of fw or resource table\n");
110 		return NULL;
111 	}
112 
113 	/* we don't support any version beyond the first */
114 	if (table->ver != 1) {
115 		sproc_err(sproc, "unsupported fw ver: %d\n", table->ver);
116 		return NULL;
117 	}
118 
119 	/* make sure reserved bytes are zeroes */
120 	if (table->reserved[0] || table->reserved[1]) {
121 		sproc_err(sproc, "non zero reserved bytes\n");
122 		return NULL;
123 	}
124 
125 	/* make sure the offsets array isn't truncated */
126 	if (table->num > SPROC_MAX_TOC_ENTRIES ||
127 	    table->num * sizeof(table->offset[0]) +
128 	    sizeof(struct resource_table) > entry->size) {
129 		sproc_err(sproc, "resource table incomplete\n");
130 		return NULL;
131 	}
132 
133 	/* If the fw size has grown, release the previous fw allocation */
134 	if (SPROC_FW_SIZE < fw->size) {
135 		sproc_err(sproc, "Insufficient space for fw (%d < %zd)\n",
136 			  SPROC_FW_SIZE, fw->size);
137 		return NULL;
138 	}
139 
140 	sproc->fw_size = fw->size;
141 	*tablesz = entry->size;
142 
143 	return table;
144 }
145 
146 /* Find the resource table inside the remote processor's firmware. */
147 static struct resource_table *
sproc_find_loaded_rsc_table(struct rproc * rproc,const struct firmware * fw)148 sproc_find_loaded_rsc_table(struct rproc *rproc, const struct firmware *fw)
149 {
150 	struct sproc *sproc = rproc->priv;
151 	const struct ste_toc_entry *entry;
152 
153 	if (!fw || !sproc->fw_addr)
154 		return NULL;
155 
156 	entry = sproc_find_rsc_entry(sproc->fw_addr);
157 	if (!entry) {
158 		sproc_err(sproc, "resource table not found in fw\n");
159 		return NULL;
160 	}
161 
162 	return sproc->fw_addr + entry->start;
163 }
164 
165 /* STE modem firmware handler operations */
166 static const struct rproc_fw_ops sproc_fw_ops = {
167 	.load = sproc_load_segments,
168 	.find_rsc_table = sproc_find_rsc_table,
169 	.find_loaded_rsc_table = sproc_find_loaded_rsc_table,
170 };
171 
172 /* Kick the modem with specified notification id */
sproc_kick(struct rproc * rproc,int vqid)173 static void sproc_kick(struct rproc *rproc, int vqid)
174 {
175 	struct sproc *sproc = rproc->priv;
176 
177 	sproc_dbg(sproc, "kick vqid:%d\n", vqid);
178 
179 	/*
180 	 * We need different notification IDs for RX and TX so add
181 	 * an offset on TX notification IDs.
182 	 */
183 	sproc->mdev->ops.kick(sproc->mdev, vqid + SPROC_MAX_NOTIFY_ID);
184 }
185 
186 /* Received a kick from a modem, kick the virtqueue */
sproc_kick_callback(struct ste_modem_device * mdev,int vqid)187 static void sproc_kick_callback(struct ste_modem_device *mdev, int vqid)
188 {
189 	struct sproc *sproc = mdev->drv_data;
190 
191 	if (rproc_vq_interrupt(sproc->rproc, vqid) == IRQ_NONE)
192 		sproc_dbg(sproc, "no message was found in vqid %d\n", vqid);
193 }
194 
195 static struct ste_modem_dev_cb sproc_dev_cb = {
196 	.kick = sproc_kick_callback,
197 };
198 
199 /* Start the STE modem */
sproc_start(struct rproc * rproc)200 static int sproc_start(struct rproc *rproc)
201 {
202 	struct sproc *sproc = rproc->priv;
203 	int i, err;
204 
205 	sproc_dbg(sproc, "start ste-modem\n");
206 
207 	/* Sanity test the max_notifyid */
208 	if (rproc->max_notifyid > SPROC_MAX_NOTIFY_ID) {
209 		sproc_err(sproc, "Notification IDs too high:%d\n",
210 			  rproc->max_notifyid);
211 		return -EINVAL;
212 	}
213 
214 	/* Subscribe to notifications */
215 	for (i = 0; i <= rproc->max_notifyid; i++) {
216 		err = sproc->mdev->ops.kick_subscribe(sproc->mdev, i);
217 		if (err) {
218 			sproc_err(sproc,
219 				  "subscription of kicks failed:%d\n", err);
220 			return err;
221 		}
222 	}
223 
224 	/* Request modem start-up*/
225 	return sproc->mdev->ops.power(sproc->mdev, true);
226 }
227 
228 /* Stop the STE modem */
sproc_stop(struct rproc * rproc)229 static int sproc_stop(struct rproc *rproc)
230 {
231 	struct sproc *sproc = rproc->priv;
232 
233 	sproc_dbg(sproc, "stop ste-modem\n");
234 
235 	return sproc->mdev->ops.power(sproc->mdev, false);
236 }
237 
238 static struct rproc_ops sproc_ops = {
239 	.start		= sproc_start,
240 	.stop		= sproc_stop,
241 	.kick		= sproc_kick,
242 };
243 
244 /* STE modem device is unregistered */
sproc_drv_remove(struct platform_device * pdev)245 static int sproc_drv_remove(struct platform_device *pdev)
246 {
247 	struct ste_modem_device *mdev =
248 		container_of(pdev, struct ste_modem_device, pdev);
249 	struct sproc *sproc = mdev->drv_data;
250 
251 	sproc_dbg(sproc, "remove ste-modem\n");
252 
253 	/* Reset device callback functions */
254 	sproc->mdev->ops.setup(sproc->mdev, NULL);
255 
256 	/* Unregister as remoteproc device */
257 	rproc_del(sproc->rproc);
258 	dma_free_coherent(sproc->rproc->dev.parent, SPROC_FW_SIZE,
259 			  sproc->fw_addr, sproc->fw_dma_addr);
260 	rproc_put(sproc->rproc);
261 
262 	mdev->drv_data = NULL;
263 
264 	return 0;
265 }
266 
267 /* Handle probe of a modem device */
sproc_probe(struct platform_device * pdev)268 static int sproc_probe(struct platform_device *pdev)
269 {
270 	struct ste_modem_device *mdev =
271 		container_of(pdev, struct ste_modem_device, pdev);
272 	struct sproc *sproc;
273 	struct rproc *rproc;
274 	int err;
275 
276 	dev_dbg(&mdev->pdev.dev, "probe ste-modem\n");
277 
278 	if (!mdev->ops.setup || !mdev->ops.kick || !mdev->ops.kick_subscribe ||
279 	    !mdev->ops.power) {
280 		dev_err(&mdev->pdev.dev, "invalid mdev ops\n");
281 		return -EINVAL;
282 	}
283 
284 	rproc = rproc_alloc(&mdev->pdev.dev, mdev->pdev.name, &sproc_ops,
285 			    SPROC_MODEM_FIRMWARE, sizeof(*sproc));
286 	if (!rproc)
287 		return -ENOMEM;
288 
289 	sproc = rproc->priv;
290 	sproc->mdev = mdev;
291 	sproc->rproc = rproc;
292 	rproc->has_iommu = false;
293 	mdev->drv_data = sproc;
294 
295 	/* Provide callback functions to modem device */
296 	sproc->mdev->ops.setup(sproc->mdev, &sproc_dev_cb);
297 
298 	/* Set the STE-modem specific firmware handler */
299 	rproc->fw_ops = &sproc_fw_ops;
300 
301 	/*
302 	 * STE-modem requires the firmware to be located
303 	 * at the start of the shared memory region. So we need to
304 	 * reserve space for firmware at the start.
305 	 */
306 	sproc->fw_addr = dma_alloc_coherent(rproc->dev.parent, SPROC_FW_SIZE,
307 					    &sproc->fw_dma_addr,
308 					    GFP_KERNEL);
309 	if (!sproc->fw_addr) {
310 		sproc_err(sproc, "Cannot allocate memory for fw\n");
311 		err = -ENOMEM;
312 		goto free_rproc;
313 	}
314 
315 	/* Register as a remoteproc device */
316 	err = rproc_add(rproc);
317 	if (err)
318 		goto free_mem;
319 
320 	return 0;
321 
322 free_mem:
323 	dma_free_coherent(rproc->dev.parent, SPROC_FW_SIZE,
324 			  sproc->fw_addr, sproc->fw_dma_addr);
325 free_rproc:
326 	/* Reset device data upon error */
327 	mdev->drv_data = NULL;
328 	rproc_put(rproc);
329 	return err;
330 }
331 
332 static struct platform_driver sproc_driver = {
333 	.driver	= {
334 		.name	= SPROC_MODEM_NAME,
335 	},
336 	.probe	= sproc_probe,
337 	.remove	= sproc_drv_remove,
338 };
339 
340 module_platform_driver(sproc_driver);
341 MODULE_LICENSE("GPL v2");
342 MODULE_DESCRIPTION("STE Modem driver using the Remote Processor Framework");
343