xref: /freebsd/sys/dev/powermac_nvram/powermac_nvram.c (revision f0a75d274af375d15b97b830966b99a02b7db911)
1 /*
2  * Copyright (c) 2006 Maxim Sobolev <sobomax@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
18  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
20  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
23  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24  * POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/module.h>
32 #include <sys/bus.h>
33 #include <sys/conf.h>
34 #include <sys/kernel.h>
35 #include <sys/uio.h>
36 
37 #include <dev/ofw/openfirm.h>
38 #include <dev/ofw/ofw_pci.h>
39 
40 #include <machine/bus.h>
41 #include <machine/md_var.h>
42 #include <machine/nexusvar.h>
43 #include <machine/resource.h>
44 
45 #include <sys/rman.h>
46 
47 #include <powerpc/ofw/ofw_pci.h>
48 #include <dev/powermac_nvram/powermac_nvramvar.h>
49 
50 #include <vm/vm.h>
51 #include <vm/pmap.h>
52 
53 /*
54  * Device interface.
55  */
56 static int		powermac_nvram_probe(device_t);
57 static int		powermac_nvram_attach(device_t);
58 static int		powermac_nvram_detach(device_t);
59 
60 /* Helper functions */
61 static int		powermac_nvram_check(void *data);
62 static int		chrp_checksum(int sum, uint8_t *, uint8_t *);
63 static uint32_t		adler_checksum(uint8_t *, int);
64 static int		erase_bank(device_t, uint8_t *);
65 static int		write_bank(device_t, uint8_t *, uint8_t *);
66 
67 /*
68  * Driver methods.
69  */
70 static device_method_t	powermac_nvram_methods[] = {
71 	/* Device interface */
72 	DEVMETHOD(device_probe,		powermac_nvram_probe),
73 	DEVMETHOD(device_attach,	powermac_nvram_attach),
74 	DEVMETHOD(device_detach,	powermac_nvram_detach),
75 
76 	{ 0, 0 }
77 };
78 
79 static driver_t	powermac_nvram_driver = {
80 	"powermac_nvram",
81 	powermac_nvram_methods,
82 	sizeof(struct powermac_nvram_softc)
83 };
84 
85 static devclass_t powermac_nvram_devclass;
86 
87 DRIVER_MODULE(powermac_nvram, nexus, powermac_nvram_driver, powermac_nvram_devclass, 0, 0);
88 
89 /*
90  * Cdev methods.
91  */
92 
93 #define	NVRAM_UNIT(dev)		minor(dev)
94 #define	NVRAM_SOFTC(unit)	((struct powermac_nvram_softc *) \
95      devclass_get_softc(powermac_nvram_devclass, unit))
96 
97 static	d_open_t	powermac_nvram_open;
98 static	d_close_t	powermac_nvram_close;
99 static	d_read_t	powermac_nvram_read;
100 static	d_write_t	powermac_nvram_write;
101 
102 static struct cdevsw powermac_nvram_cdevsw = {
103 	.d_version =	D_VERSION,
104 	.d_flags =	D_NEEDGIANT,
105 	.d_open =	powermac_nvram_open,
106 	.d_close =	powermac_nvram_close,
107 	.d_read =	powermac_nvram_read,
108 	.d_write =	powermac_nvram_write,
109 	.d_name =	"powermac_nvram",
110 };
111 
112 static int
113 powermac_nvram_probe(device_t dev)
114 {
115 	char	*type, *compatible;
116 
117 	type = nexus_get_device_type(dev);
118 	compatible = nexus_get_compatible(dev);
119 
120 	if (type == NULL || compatible == NULL)
121 		return ENXIO;
122 
123 	if (strcmp(type, "nvram") != 0 || strcmp(compatible, "amd-0137") != 0)
124 		return ENXIO;
125 
126 	device_set_desc(dev, "Apple NVRAM");
127 	return 0;
128 }
129 
130 static int
131 powermac_nvram_attach(device_t dev)
132 {
133 	struct powermac_nvram_softc *sc;
134 	phandle_t node;
135 	u_int32_t reg[2];
136 	int gen0, gen1;
137 
138 	node = nexus_get_node(dev);
139 	sc = device_get_softc(dev);
140 
141 	if (OF_getprop(node, "reg", reg, sizeof(reg)) < 8)
142 		return ENXIO;
143 
144 	sc->sc_dev = dev;
145 	sc->sc_node = node;
146 
147 	sc->sc_bank0 = (vm_offset_t)pmap_mapdev(reg[0], NVRAM_SIZE * 2);
148 	sc->sc_bank1 = sc->sc_bank0 + NVRAM_SIZE;
149 
150 	gen0 = powermac_nvram_check((void *)sc->sc_bank0);
151 	gen1 = powermac_nvram_check((void *)sc->sc_bank1);
152 
153 	if (gen0 == -1 && gen1 == -1) {
154 		if ((void *)sc->sc_bank0 != NULL)
155 			pmap_unmapdev(sc->sc_bank0, NVRAM_SIZE * 2);
156 		device_printf(dev, "both banks appear to be corrupt\n");
157 		return ENXIO;
158 	}
159 	device_printf(dev, "bank0 generation %d, bank1 generation %d\n",
160 	    gen0, gen1);
161 
162 	sc->sc_bank = (gen0 > gen1) ? sc->sc_bank0 : sc->sc_bank1;
163 	bcopy((void *)sc->sc_bank, (void *)sc->sc_data, NVRAM_SIZE);
164 
165 	sc->sc_cdev = make_dev(&powermac_nvram_cdevsw, 0, 0, 0, 0600,
166 	    "powermac_nvram");
167 
168 	return 0;
169 }
170 
171 static int
172 powermac_nvram_detach(device_t dev)
173 {
174 	struct powermac_nvram_softc *sc;
175 
176 	sc = device_get_softc(dev);
177 
178 	if ((void *)sc->sc_bank0 != NULL)
179 		pmap_unmapdev(sc->sc_bank0, NVRAM_SIZE * 2);
180 
181 	if (sc->sc_cdev != NULL)
182 		destroy_dev(sc->sc_cdev);
183 
184 	return 0;
185 }
186 
187 static int
188 powermac_nvram_open(struct cdev *dev, int flags, int fmt, struct thread *td)
189 {
190 	struct powermac_nvram_softc *sc;
191 
192 	sc = NVRAM_SOFTC(NVRAM_UNIT(dev));
193 	if (sc->sc_isopen)
194 		return EBUSY;
195 	sc->sc_isopen = 1;
196 	sc->sc_rpos = sc->sc_wpos = 0;
197 	return 0;
198 }
199 
200 static int
201 powermac_nvram_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
202 {
203 	struct powermac_nvram_softc *sc;
204 	struct core99_header *header;
205 	vm_offset_t bank;
206 
207 	sc = NVRAM_SOFTC(NVRAM_UNIT(dev));
208 
209 	if (sc->sc_wpos != sizeof(sc->sc_data)) {
210 		/* Short write, restore in-memory copy */
211 		bcopy((void *)sc->sc_bank, (void *)sc->sc_data, NVRAM_SIZE);
212 		sc->sc_isopen = 0;
213 		return 0;
214 	}
215 
216 	header = (struct core99_header *)sc->sc_data;
217 
218 	header->generation = ((struct core99_header *)sc->sc_bank)->generation;
219 	header->generation++;
220 	header->chrp_header.signature = CORE99_SIGNATURE;
221 
222 	header->adler_checksum =
223 	    adler_checksum((uint8_t *)&(header->generation),
224 	    NVRAM_SIZE - offsetof(struct core99_header, generation));
225 	header->chrp_header.chrp_checksum = chrp_checksum(header->chrp_header.signature,
226 	    (uint8_t *)&(header->chrp_header.length),
227 	    (uint8_t *)&(header->adler_checksum));
228 
229 	bank = (sc->sc_bank == sc->sc_bank0) ? sc->sc_bank1 : sc->sc_bank0;
230 	if (erase_bank(sc->sc_dev, (uint8_t *)bank) != 0 ||
231 	    write_bank(sc->sc_dev, (uint8_t *)bank, sc->sc_data) != 0) {
232 		sc->sc_isopen = 0;
233 		return ENOSPC;
234 	}
235 	sc->sc_bank = bank;
236 	sc->sc_isopen = 0;
237 	return 0;
238 }
239 
240 static int
241 powermac_nvram_read(struct cdev *dev, struct uio *uio, int ioflag)
242 {
243 	int rv, amnt, data_available;
244 	struct powermac_nvram_softc *sc;
245 
246 	sc = NVRAM_SOFTC(NVRAM_UNIT(dev));
247 
248 	rv = 0;
249 	while (uio->uio_resid > 0) {
250 		data_available = sizeof(sc->sc_data) - sc->sc_rpos;
251 		if (data_available > 0) {
252 			amnt = MIN(uio->uio_resid, data_available);
253 			rv = uiomove((void *)(sc->sc_data + sc->sc_rpos),
254 			    amnt, uio);
255 			if (rv != 0)
256 				break;
257 			sc->sc_rpos += amnt;
258 		} else {
259 			break;
260 		}
261 	}
262 	return rv;
263 }
264 
265 static int
266 powermac_nvram_write(struct cdev *dev, struct uio *uio, int ioflag)
267 {
268 	int rv, amnt, data_available;
269 	struct powermac_nvram_softc *sc;
270 
271 	sc = NVRAM_SOFTC(NVRAM_UNIT(dev));
272 
273 	if (sc->sc_wpos >= sizeof(sc->sc_data))
274 		return EINVAL;
275 
276 	rv = 0;
277 	while (uio->uio_resid > 0) {
278 		data_available = sizeof(sc->sc_data) - sc->sc_wpos;
279 		if (data_available > 0) {
280 			amnt = MIN(uio->uio_resid, data_available);
281 			rv = uiomove((void *)(sc->sc_data + sc->sc_wpos),
282 			    amnt, uio);
283 			if (rv != 0)
284 				break;
285 			sc->sc_wpos += amnt;
286 		} else {
287 			break;
288 		}
289 	}
290 	return rv;
291 }
292 
293 static int
294 powermac_nvram_check(void *data)
295 {
296 	struct core99_header *header;
297 
298 	header = (struct core99_header *)data;
299 
300 	if (header->chrp_header.signature != CORE99_SIGNATURE)
301 		return -1;
302 	if (header->chrp_header.chrp_checksum !=
303 	    chrp_checksum(header->chrp_header.signature,
304 	    (uint8_t *)&(header->chrp_header.length),
305 	    (uint8_t *)&(header->adler_checksum)))
306 		return -1;
307 	if (header->adler_checksum !=
308 	    adler_checksum((uint8_t *)&(header->generation),
309 	    NVRAM_SIZE - offsetof(struct core99_header, generation)))
310 		return -1;
311 	return header->generation;
312 }
313 
314 static int
315 chrp_checksum(int sum, uint8_t *data, uint8_t *end)
316 {
317 
318 	for (; data < end; data++)
319 		sum += data[0];
320 	while (sum > 0xff)
321 		sum = (sum & 0xff) + (sum >> 8);
322 	return sum;
323 }
324 
325 static uint32_t
326 adler_checksum(uint8_t *data, int len)
327 {
328 	uint32_t low, high;
329 	int i;
330 
331 	low = 1;
332 	high = 0;
333 	for (i = 0; i < len; i++) {
334 		if ((i % 5000) == 0) {
335 			high %= 65521UL;
336 			high %= 65521UL;
337 		}
338 		low += data[i];
339 		high += low;
340 	}
341 	low %= 65521UL;
342 	high %= 65521UL;
343 
344 	return (high << 16) | low;
345 }
346 
347 #define	OUTB_DELAY(a, v)	outb(a, v); DELAY(1);
348 
349 static int
350 wait_operation_complete(uint8_t *bank)
351 {
352 	int i;
353 
354 	for (i = 1000000; i != 0; i--)
355 		if ((inb(bank) ^ inb(bank)) == 0)
356 			return 0;
357 	return -1;
358 }
359 
360 static int
361 erase_bank(device_t dev, uint8_t *bank)
362 {
363 	unsigned int i;
364 
365 	/* Unlock 1 */
366 	OUTB_DELAY(bank + 0x555, 0xaa);
367 	/* Unlock 2 */
368 	OUTB_DELAY(bank + 0x2aa, 0x55);
369 
370 	/* Sector-Erase */
371 	OUTB_DELAY(bank + 0x555, 0x80);
372 	OUTB_DELAY(bank + 0x555, 0xaa);
373 	OUTB_DELAY(bank + 0x2aa, 0x55);
374 	OUTB_DELAY(bank, 0x30);
375 
376 	if (wait_operation_complete(bank) != 0) {
377 		device_printf(dev, "flash erase timeout\n");
378 		return -1;
379 	}
380 
381 	/* Reset */
382 	OUTB_DELAY(bank, 0xf0);
383 
384 	for (i = 0; i < NVRAM_SIZE; i++) {
385 		if (bank[i] != 0xff) {
386 			device_printf(dev, "flash erase has failed\n");
387 			return -1;
388 		}
389 	}
390 	return 0;
391 }
392 
393 static int
394 write_bank(device_t dev, uint8_t *bank, uint8_t *data)
395 {
396 	unsigned int i;
397 
398 	for (i = 0; i < NVRAM_SIZE; i++) {
399 		/* Unlock 1 */
400 		OUTB_DELAY(bank + 0x555, 0xaa);
401 		/* Unlock 2 */
402 		OUTB_DELAY(bank + 0x2aa, 0x55);
403 
404 		/* Write single word */
405 		OUTB_DELAY(bank + 0x555, 0xa0);
406 		OUTB_DELAY(bank + i, data[i]);
407 		if (wait_operation_complete(bank) != 0) {
408 			device_printf(dev, "flash write timeout\n");
409 			return -1;
410 		}
411 	}
412 
413 	/* Reset */
414 	OUTB_DELAY(bank, 0xf0);
415 
416 	for (i = 0; i < NVRAM_SIZE; i++) {
417 		if (bank[i] != data[i]) {
418 			device_printf(dev, "flash write has failed\n");
419 			return -1;
420 		}
421 	}
422 	return 0;
423 }
424