1/*
2 * Copyright (C) 2012 CERN (www.cern.ch)
3 * Author: Alessandro Rubini <rubini@gnudd.com>
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * The software is provided "as is"; the copyright holders disclaim
10 * all warranties and liabilities, to the extent permitted by
11 * applicable law.
12 */
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/string.h>
16#include <linux/device.h>
17#include <linux/slab.h>
18#include <linux/firmware.h>
19#include <linux/workqueue.h>
20#include <linux/err.h>
21#include <linux/fmc.h>
22
23#define FF_EEPROM_SIZE		8192	/* The standard eeprom size */
24#define FF_MAX_MEZZANINES	4	/* Fakes a multi-mezzanine carrier */
25
26/* The user can pass up to 4 names of eeprom images to load */
27static char *ff_eeprom[FF_MAX_MEZZANINES];
28static int ff_nr_eeprom;
29module_param_array_named(eeprom, ff_eeprom, charp, &ff_nr_eeprom, 0444);
30
31/* The user can ask for a multi-mezzanine carrier, with the default eeprom */
32static int ff_nr_dev = 1;
33module_param_named(ndev, ff_nr_dev, int, 0444);
34
35
36/* Lazily, don't support the "standard" module parameters */
37
38/*
39 * Eeprom built from these commands:
40
41	../fru-generator -v fake-vendor -n fake-design-for-testing \
42		-s 01234 -p none > IPMI-FRU
43
44	gensdbfs . ../fake-eeprom.bin
45*/
46static char ff_eeimg[FF_MAX_MEZZANINES][FF_EEPROM_SIZE] = {
47	{
48	0x01, 0x00, 0x00, 0x01, 0x00, 0x0c, 0x00, 0xf2, 0x01, 0x0b, 0x00, 0xb2,
49	0x86, 0x87, 0xcb, 0x66, 0x61, 0x6b, 0x65, 0x2d, 0x76, 0x65, 0x6e, 0x64,
50	0x6f, 0x72, 0xd7, 0x66, 0x61, 0x6b, 0x65, 0x2d, 0x64, 0x65, 0x73, 0x69,
51	0x67, 0x6e, 0x2d, 0x66, 0x6f, 0x72, 0x2d, 0x74, 0x65, 0x73, 0x74, 0x69,
52	0x6e, 0x67, 0xc5, 0x30, 0x31, 0x32, 0x33, 0x34, 0xc4, 0x6e, 0x6f, 0x6e,
53	0x65, 0xda, 0x32, 0x30, 0x31, 0x32, 0x2d, 0x31, 0x31, 0x2d, 0x31, 0x39,
54	0x20, 0x32, 0x32, 0x3a, 0x34, 0x32, 0x3a, 0x33, 0x30, 0x2e, 0x30, 0x37,
55	0x34, 0x30, 0x35, 0x35, 0xc1, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x87,
56	0x02, 0x02, 0x0d, 0xf7, 0xf8, 0x02, 0xb0, 0x04, 0x74, 0x04, 0xec, 0x04,
57	0x00, 0x00, 0x00, 0x00, 0xe8, 0x03, 0x02, 0x02, 0x0d, 0x5c, 0x93, 0x01,
58	0x4a, 0x01, 0x39, 0x01, 0x5a, 0x01, 0x00, 0x00, 0x00, 0x00, 0xb8, 0x0b,
59	0x02, 0x02, 0x0d, 0x63, 0x8c, 0x00, 0xfa, 0x00, 0xed, 0x00, 0x06, 0x01,
60	0x00, 0x00, 0x00, 0x00, 0xa0, 0x0f, 0x01, 0x02, 0x0d, 0xfb, 0xf5, 0x05,
61	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
62	0x01, 0x02, 0x0d, 0xfc, 0xf4, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
63	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x0d, 0xfd, 0xf3, 0x03,
64	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
65	0xfa, 0x82, 0x0b, 0xea, 0x8f, 0xa2, 0x12, 0x00, 0x00, 0x1e, 0x44, 0x00,
66	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
67	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
68	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
69	0x00, 0x00, 0x00, 0x00, 0x53, 0x44, 0x42, 0x2d, 0x00, 0x03, 0x01, 0x01,
70	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
71	0x00, 0x00, 0x01, 0xc4, 0x46, 0x69, 0x6c, 0x65, 0x44, 0x61, 0x74, 0x61,
72	0x2e, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
73	0x2e, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
74	0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00,
75	0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xc0,
76	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xc4, 0x46, 0x69, 0x6c, 0x65,
77	0x44, 0x61, 0x74, 0x61, 0x6e, 0x61, 0x6d, 0x65, 0x00, 0x00, 0x00, 0x01,
78	0x00, 0x00, 0x00, 0x00, 0x6e, 0x61, 0x6d, 0x65, 0x20, 0x20, 0x20, 0x20,
79	0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x01,
80	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00,
81	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xdf,
82	0x46, 0x69, 0x6c, 0x65, 0x44, 0x61, 0x74, 0x61, 0x49, 0x50, 0x4d, 0x49,
83	0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x49, 0x50, 0x4d, 0x49,
84	0x2d, 0x46, 0x52, 0x55, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
85	0x20, 0x20, 0x20, 0x01, 0x66, 0x61, 0x6b, 0x65, 0x0a,
86	},
87};
88
89struct ff_dev {
90	struct fmc_device *fmc[FF_MAX_MEZZANINES];
91	struct device dev;
92};
93
94static struct ff_dev *ff_current_dev; /* We have 1 carrier, 1 slot */
95
96static int ff_reprogram(struct fmc_device *fmc, struct fmc_driver *drv,
97			  char *gw)
98{
99	const struct firmware *fw;
100	int ret;
101
102	if (!gw) {
103		/* program golden: success */
104		fmc->flags &= ~FMC_DEVICE_HAS_CUSTOM;
105		fmc->flags |= FMC_DEVICE_HAS_GOLDEN;
106		return 0;
107	}
108
109	dev_info(&fmc->dev, "reprogramming with %s\n", gw);
110	ret = request_firmware(&fw, gw, &fmc->dev);
111	if (ret < 0) {
112		dev_warn(&fmc->dev, "request firmware \"%s\": error %i\n",
113			 gw, ret);
114		goto out;
115	}
116	fmc->flags &= ~FMC_DEVICE_HAS_GOLDEN;
117	fmc->flags |= FMC_DEVICE_HAS_CUSTOM;
118
119out:
120	release_firmware(fw);
121	return ret;
122}
123
124static int ff_irq_request(struct fmc_device *fmc, irq_handler_t handler,
125			    char *name, int flags)
126{
127	return -EOPNOTSUPP;
128}
129
130/* FIXME: should also have some fake FMC GPIO mapping */
131
132
133/*
134 * This work function is called when we changed the eeprom. It removes the
135 * current fmc device and registers a new one, with different identifiers.
136 */
137static struct ff_dev *ff_dev_create(void); /* defined later */
138
139static void ff_work_fn(struct work_struct *work)
140{
141	struct ff_dev *ff = ff_current_dev;
142	int ret;
143
144	fmc_device_unregister_n(ff->fmc, ff_nr_dev);
145	device_unregister(&ff->dev);
146	ff_current_dev = NULL;
147
148	ff = ff_dev_create();
149	if (IS_ERR(ff)) {
150		pr_warning("%s: can't re-create FMC devices\n", __func__);
151		return;
152	}
153	ret = fmc_device_register_n(ff->fmc, ff_nr_dev);
154	if (ret < 0) {
155		dev_warn(&ff->dev, "can't re-register FMC devices\n");
156		device_unregister(&ff->dev);
157		return;
158	}
159
160	ff_current_dev = ff;
161}
162
163static DECLARE_DELAYED_WORK(ff_work, ff_work_fn);
164
165
166/* low-level i2c */
167static int ff_eeprom_read(struct fmc_device *fmc, uint32_t offset,
168		void *buf, size_t size)
169{
170	if (offset > FF_EEPROM_SIZE)
171		return -EINVAL;
172	if (offset + size > FF_EEPROM_SIZE)
173		size = FF_EEPROM_SIZE - offset;
174	memcpy(buf, fmc->eeprom + offset, size);
175	return size;
176}
177
178static int ff_eeprom_write(struct fmc_device *fmc, uint32_t offset,
179		    const void *buf, size_t size)
180{
181	if (offset > FF_EEPROM_SIZE)
182		return -EINVAL;
183	if (offset + size > FF_EEPROM_SIZE)
184		size = FF_EEPROM_SIZE - offset;
185	dev_info(&fmc->dev, "write_eeprom: offset %i, size %zi\n",
186		 (int)offset, size);
187	memcpy(fmc->eeprom + offset, buf, size);
188	schedule_delayed_work(&ff_work, HZ * 2); /* remove, replug, in 2s */
189	return size;
190}
191
192/* i2c operations for fmc */
193static int ff_read_ee(struct fmc_device *fmc, int pos, void *data, int len)
194{
195	if (!(fmc->flags & FMC_DEVICE_HAS_GOLDEN))
196		return -EOPNOTSUPP;
197	return ff_eeprom_read(fmc, pos, data, len);
198}
199
200static int ff_write_ee(struct fmc_device *fmc, int pos,
201			 const void *data, int len)
202{
203	if (!(fmc->flags & FMC_DEVICE_HAS_GOLDEN))
204		return -EOPNOTSUPP;
205	return ff_eeprom_write(fmc, pos, data, len);
206}
207
208/* readl and writel do not do anything. Don't waste RAM with "base" */
209static uint32_t ff_readl(struct fmc_device *fmc, int offset)
210{
211	return 0;
212}
213
214static void ff_writel(struct fmc_device *fmc, uint32_t value, int offset)
215{
216	return;
217}
218
219/* validate is useful so fmc-write-eeprom will not reprogram every 2 seconds */
220static int ff_validate(struct fmc_device *fmc, struct fmc_driver *drv)
221{
222	int i;
223
224	if (!drv->busid_n)
225		return 0; /* everyhing is valid */
226	for (i = 0; i < drv->busid_n; i++)
227		if (drv->busid_val[i] == fmc->device_id)
228			return i;
229	return -ENOENT;
230}
231
232
233
234static struct fmc_operations ff_fmc_operations = {
235	.read32 =		ff_readl,
236	.write32 =		ff_writel,
237	.reprogram =		ff_reprogram,
238	.irq_request =		ff_irq_request,
239	.read_ee =		ff_read_ee,
240	.write_ee =		ff_write_ee,
241	.validate =		ff_validate,
242};
243
244/* This device is kmalloced: release it */
245static void ff_dev_release(struct device *dev)
246{
247	struct ff_dev *ff = container_of(dev, struct ff_dev, dev);
248	kfree(ff);
249}
250
251static struct fmc_device ff_template_fmc = {
252	.version = FMC_VERSION,
253	.owner = THIS_MODULE,
254	.carrier_name = "fake-fmc-carrier",
255	.device_id = 0xf001, /* fool */
256	.eeprom_len = sizeof(ff_eeimg[0]),
257	.memlen = 0x1000, /* 4k, to show something */
258	.op = &ff_fmc_operations,
259	.hwdev = NULL, /* filled at creation time */
260	.flags = FMC_DEVICE_HAS_GOLDEN,
261};
262
263static struct ff_dev *ff_dev_create(void)
264{
265	struct ff_dev *ff;
266	struct fmc_device *fmc;
267	int i, ret;
268
269	ff = kzalloc(sizeof(*ff), GFP_KERNEL);
270	if (!ff)
271		return ERR_PTR(-ENOMEM);
272	dev_set_name(&ff->dev, "fake-fmc-carrier");
273	ff->dev.release = ff_dev_release;
274
275	ret = device_register(&ff->dev);
276	if (ret < 0) {
277		put_device(&ff->dev);
278		return ERR_PTR(ret);
279	}
280
281	/* Create fmc structures that refer to this new "hw" device */
282	for (i = 0; i < ff_nr_dev; i++) {
283		fmc = kmemdup(&ff_template_fmc, sizeof(ff_template_fmc),
284			      GFP_KERNEL);
285		fmc->hwdev = &ff->dev;
286		fmc->carrier_data = ff;
287		fmc->nr_slots = ff_nr_dev;
288		/* the following fields are different for each slot */
289		fmc->eeprom = ff_eeimg[i];
290		fmc->eeprom_addr = 0x50 + 2 * i;
291		fmc->slot_id = i;
292		ff->fmc[i] = fmc;
293		/* increment the identifier, each must be different */
294		ff_template_fmc.device_id++;
295	}
296	return ff;
297}
298
299/* init and exit */
300static int ff_init(void)
301{
302	struct ff_dev *ff;
303	const struct firmware *fw;
304	int i, len, ret = 0;
305
306	/* Replicate the default eeprom for the max number of mezzanines */
307	for (i = 1; i < FF_MAX_MEZZANINES; i++)
308		memcpy(ff_eeimg[i], ff_eeimg[0], sizeof(ff_eeimg[0]));
309
310	if (ff_nr_eeprom > ff_nr_dev)
311		ff_nr_dev = ff_nr_eeprom;
312
313	ff = ff_dev_create();
314	if (IS_ERR(ff))
315		return PTR_ERR(ff);
316
317	/* If the user passed "eeprom=" as a parameter, fetch them */
318	for (i = 0; i < ff_nr_eeprom; i++) {
319		if (!strlen(ff_eeprom[i]))
320			continue;
321		ret = request_firmware(&fw, ff_eeprom[i], &ff->dev);
322		if (ret < 0) {
323			dev_err(&ff->dev, "Mezzanine %i: can't load \"%s\" "
324				"(error %i)\n", i, ff_eeprom[i], -ret);
325		} else {
326			len = min_t(size_t, fw->size, (size_t)FF_EEPROM_SIZE);
327			memcpy(ff_eeimg[i], fw->data, len);
328			release_firmware(fw);
329			dev_info(&ff->dev, "Mezzanine %i: eeprom \"%s\"\n", i,
330				ff_eeprom[i]);
331		}
332	}
333
334	ret = fmc_device_register_n(ff->fmc, ff_nr_dev);
335	if (ret) {
336		device_unregister(&ff->dev);
337		return ret;
338	}
339	ff_current_dev = ff;
340	return ret;
341}
342
343static void ff_exit(void)
344{
345	if (ff_current_dev) {
346		fmc_device_unregister_n(ff_current_dev->fmc, ff_nr_dev);
347		device_unregister(&ff_current_dev->dev);
348	}
349	cancel_delayed_work_sync(&ff_work);
350}
351
352module_init(ff_init);
353module_exit(ff_exit);
354
355MODULE_LICENSE("Dual BSD/GPL");
356