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 */
 26struct 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 */
 36struct 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 */
 52struct ste_toc {
 53	struct ste_toc_entry table[SPROC_MAX_TOC_ENTRIES];
 54};
 55
 56/* Loads the firmware to shared memory. */
 57static 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 */
 67static 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. */
 84static struct resource_table *
 85sproc_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. */
147static struct resource_table *
148sproc_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 */
166static 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 */
173static 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 */
187static 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
195static struct ste_modem_dev_cb sproc_dev_cb = {
196	.kick = sproc_kick_callback,
197};
198
199/* Start the STE modem */
200static 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 */
229static 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
238static 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 */
245static 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 */
268static 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
322free_mem:
323	dma_free_coherent(rproc->dev.parent, SPROC_FW_SIZE,
324			  sproc->fw_addr, sproc->fw_dma_addr);
325free_rproc:
326	/* Reset device data upon error */
327	mdev->drv_data = NULL;
328	rproc_put(rproc);
329	return err;
330}
331
332static struct platform_driver sproc_driver = {
333	.driver	= {
334		.name	= SPROC_MODEM_NAME,
335	},
336	.probe	= sproc_probe,
337	.remove	= sproc_drv_remove,
338};
339
340module_platform_driver(sproc_driver);
341MODULE_LICENSE("GPL v2");
342MODULE_DESCRIPTION("STE Modem driver using the Remote Processor Framework");