xref: /freebsd/sys/dev/powermac_nvram/powermac_nvram.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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/pio.h>
44 #include <machine/resource.h>
45 
46 #include <sys/rman.h>
47 
48 #include <powerpc/ofw/ofw_pci.h>
49 #include <dev/powermac_nvram/powermac_nvramvar.h>
50 
51 #include <vm/vm.h>
52 #include <vm/pmap.h>
53 
54 /*
55  * Device interface.
56  */
57 static int		powermac_nvram_probe(device_t);
58 static int		powermac_nvram_attach(device_t);
59 static int		powermac_nvram_detach(device_t);
60 
61 /* Helper functions */
62 static int		powermac_nvram_check(void *data);
63 static int		chrp_checksum(int sum, uint8_t *, uint8_t *);
64 static uint32_t		adler_checksum(uint8_t *, int);
65 static int		erase_bank(device_t, uint8_t *);
66 static int		write_bank(device_t, uint8_t *, uint8_t *);
67 
68 /*
69  * Driver methods.
70  */
71 static device_method_t	powermac_nvram_methods[] = {
72 	/* Device interface */
73 	DEVMETHOD(device_probe,		powermac_nvram_probe),
74 	DEVMETHOD(device_attach,	powermac_nvram_attach),
75 	DEVMETHOD(device_detach,	powermac_nvram_detach),
76 
77 	{ 0, 0 }
78 };
79 
80 static driver_t	powermac_nvram_driver = {
81 	"powermac_nvram",
82 	powermac_nvram_methods,
83 	sizeof(struct powermac_nvram_softc)
84 };
85 
86 static devclass_t powermac_nvram_devclass;
87 
88 DRIVER_MODULE(powermac_nvram, nexus, powermac_nvram_driver, powermac_nvram_devclass, 0, 0);
89 
90 /*
91  * Cdev methods.
92  */
93 
94 #define	NVRAM_UNIT(dev)		minor(dev)
95 #define	NVRAM_SOFTC(unit)	((struct powermac_nvram_softc *) \
96      devclass_get_softc(powermac_nvram_devclass, unit))
97 
98 static	d_open_t	powermac_nvram_open;
99 static	d_close_t	powermac_nvram_close;
100 static	d_read_t	powermac_nvram_read;
101 static	d_write_t	powermac_nvram_write;
102 
103 static struct cdevsw powermac_nvram_cdevsw = {
104 	.d_version =	D_VERSION,
105 	.d_flags =	D_NEEDGIANT,
106 	.d_open =	powermac_nvram_open,
107 	.d_close =	powermac_nvram_close,
108 	.d_read =	powermac_nvram_read,
109 	.d_write =	powermac_nvram_write,
110 	.d_name =	"powermac_nvram",
111 };
112 
113 static int
114 powermac_nvram_probe(device_t dev)
115 {
116 	char	*type, *compatible;
117 
118 	type = nexus_get_device_type(dev);
119 	compatible = nexus_get_compatible(dev);
120 
121 	if (type == NULL || compatible == NULL)
122 		return ENXIO;
123 
124 	if (strcmp(type, "nvram") != 0 || strcmp(compatible, "amd-0137") != 0)
125 		return ENXIO;
126 
127 	device_set_desc(dev, "Apple NVRAM");
128 	return 0;
129 }
130 
131 static int
132 powermac_nvram_attach(device_t dev)
133 {
134 	struct powermac_nvram_softc *sc;
135 	phandle_t node;
136 	u_int32_t reg[2];
137 	int gen0, gen1;
138 
139 	node = nexus_get_node(dev);
140 	sc = device_get_softc(dev);
141 
142 	if (OF_getprop(node, "reg", reg, sizeof(reg)) < 8)
143 		return ENXIO;
144 
145 	sc->sc_dev = dev;
146 	sc->sc_node = node;
147 
148 	sc->sc_bank0 = (vm_offset_t)pmap_mapdev(reg[0], NVRAM_SIZE * 2);
149 	sc->sc_bank1 = sc->sc_bank0 + NVRAM_SIZE;
150 
151 	gen0 = powermac_nvram_check((void *)sc->sc_bank0);
152 	gen1 = powermac_nvram_check((void *)sc->sc_bank1);
153 
154 	if (gen0 == -1 && gen1 == -1) {
155 		if ((void *)sc->sc_bank0 != NULL)
156 			pmap_unmapdev(sc->sc_bank0, NVRAM_SIZE * 2);
157 		device_printf(dev, "both banks appear to be corrupt\n");
158 		return ENXIO;
159 	}
160 	device_printf(dev, "bank0 generation %d, bank1 generation %d\n",
161 	    gen0, gen1);
162 
163 	sc->sc_bank = (gen0 > gen1) ? sc->sc_bank0 : sc->sc_bank1;
164 	bcopy((void *)sc->sc_bank, (void *)sc->sc_data, NVRAM_SIZE);
165 
166 	sc->sc_cdev = make_dev(&powermac_nvram_cdevsw, 0, 0, 0, 0600,
167 	    "powermac_nvram");
168 
169 	return 0;
170 }
171 
172 static int
173 powermac_nvram_detach(device_t dev)
174 {
175 	struct powermac_nvram_softc *sc;
176 
177 	sc = device_get_softc(dev);
178 
179 	if ((void *)sc->sc_bank0 != NULL)
180 		pmap_unmapdev(sc->sc_bank0, NVRAM_SIZE * 2);
181 
182 	if (sc->sc_cdev != NULL)
183 		destroy_dev(sc->sc_cdev);
184 
185 	return 0;
186 }
187 
188 static int
189 powermac_nvram_open(struct cdev *dev, int flags, int fmt, struct thread *td)
190 {
191 	struct powermac_nvram_softc *sc;
192 
193 	sc = NVRAM_SOFTC(NVRAM_UNIT(dev));
194 	if (sc->sc_isopen)
195 		return EBUSY;
196 	sc->sc_isopen = 1;
197 	sc->sc_rpos = sc->sc_wpos = 0;
198 	return 0;
199 }
200 
201 static int
202 powermac_nvram_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
203 {
204 	struct powermac_nvram_softc *sc;
205 	struct core99_header *header;
206 	vm_offset_t bank;
207 
208 	sc = NVRAM_SOFTC(NVRAM_UNIT(dev));
209 
210 	if (sc->sc_wpos != sizeof(sc->sc_data)) {
211 		/* Short write, restore in-memory copy */
212 		bcopy((void *)sc->sc_bank, (void *)sc->sc_data, NVRAM_SIZE);
213 		sc->sc_isopen = 0;
214 		return 0;
215 	}
216 
217 	header = (struct core99_header *)sc->sc_data;
218 
219 	header->generation = ((struct core99_header *)sc->sc_bank)->generation;
220 	header->generation++;
221 	header->chrp_header.signature = CORE99_SIGNATURE;
222 
223 	header->adler_checksum =
224 	    adler_checksum((uint8_t *)&(header->generation),
225 	    NVRAM_SIZE - offsetof(struct core99_header, generation));
226 	header->chrp_header.chrp_checksum = chrp_checksum(header->chrp_header.signature,
227 	    (uint8_t *)&(header->chrp_header.length),
228 	    (uint8_t *)&(header->adler_checksum));
229 
230 	bank = (sc->sc_bank == sc->sc_bank0) ? sc->sc_bank1 : sc->sc_bank0;
231 	if (erase_bank(sc->sc_dev, (uint8_t *)bank) != 0 ||
232 	    write_bank(sc->sc_dev, (uint8_t *)bank, sc->sc_data) != 0) {
233 		sc->sc_isopen = 0;
234 		return ENOSPC;
235 	}
236 	sc->sc_bank = bank;
237 	sc->sc_isopen = 0;
238 	return 0;
239 }
240 
241 static int
242 powermac_nvram_read(struct cdev *dev, struct uio *uio, int ioflag)
243 {
244 	int rv, amnt, data_available;
245 	struct powermac_nvram_softc *sc;
246 
247 	sc = NVRAM_SOFTC(NVRAM_UNIT(dev));
248 
249 	rv = 0;
250 	while (uio->uio_resid > 0) {
251 		data_available = sizeof(sc->sc_data) - sc->sc_rpos;
252 		if (data_available > 0) {
253 			amnt = MIN(uio->uio_resid, data_available);
254 			rv = uiomove((void *)(sc->sc_data + sc->sc_rpos),
255 			    amnt, uio);
256 			if (rv != 0)
257 				break;
258 			sc->sc_rpos += amnt;
259 		} else {
260 			break;
261 		}
262 	}
263 	return rv;
264 }
265 
266 static int
267 powermac_nvram_write(struct cdev *dev, struct uio *uio, int ioflag)
268 {
269 	int rv, amnt, data_available;
270 	struct powermac_nvram_softc *sc;
271 
272 	sc = NVRAM_SOFTC(NVRAM_UNIT(dev));
273 
274 	if (sc->sc_wpos >= sizeof(sc->sc_data))
275 		return EINVAL;
276 
277 	rv = 0;
278 	while (uio->uio_resid > 0) {
279 		data_available = sizeof(sc->sc_data) - sc->sc_wpos;
280 		if (data_available > 0) {
281 			amnt = MIN(uio->uio_resid, data_available);
282 			rv = uiomove((void *)(sc->sc_data + sc->sc_wpos),
283 			    amnt, uio);
284 			if (rv != 0)
285 				break;
286 			sc->sc_wpos += amnt;
287 		} else {
288 			break;
289 		}
290 	}
291 	return rv;
292 }
293 
294 static int
295 powermac_nvram_check(void *data)
296 {
297 	struct core99_header *header;
298 
299 	header = (struct core99_header *)data;
300 
301 	if (header->chrp_header.signature != CORE99_SIGNATURE)
302 		return -1;
303 	if (header->chrp_header.chrp_checksum !=
304 	    chrp_checksum(header->chrp_header.signature,
305 	    (uint8_t *)&(header->chrp_header.length),
306 	    (uint8_t *)&(header->adler_checksum)))
307 		return -1;
308 	if (header->adler_checksum !=
309 	    adler_checksum((uint8_t *)&(header->generation),
310 	    NVRAM_SIZE - offsetof(struct core99_header, generation)))
311 		return -1;
312 	return header->generation;
313 }
314 
315 static int
316 chrp_checksum(int sum, uint8_t *data, uint8_t *end)
317 {
318 
319 	for (; data < end; data++)
320 		sum += data[0];
321 	while (sum > 0xff)
322 		sum = (sum & 0xff) + (sum >> 8);
323 	return sum;
324 }
325 
326 static uint32_t
327 adler_checksum(uint8_t *data, int len)
328 {
329 	uint32_t low, high;
330 	int i;
331 
332 	low = 1;
333 	high = 0;
334 	for (i = 0; i < len; i++) {
335 		if ((i % 5000) == 0) {
336 			high %= 65521UL;
337 			high %= 65521UL;
338 		}
339 		low += data[i];
340 		high += low;
341 	}
342 	low %= 65521UL;
343 	high %= 65521UL;
344 
345 	return (high << 16) | low;
346 }
347 
348 #define	OUTB_DELAY(a, v)	outb(a, v); DELAY(1);
349 
350 static int
351 wait_operation_complete(uint8_t *bank)
352 {
353 	int i;
354 
355 	for (i = 1000000; i != 0; i--)
356 		if ((inb(bank) ^ inb(bank)) == 0)
357 			return 0;
358 	return -1;
359 }
360 
361 static int
362 erase_bank(device_t dev, uint8_t *bank)
363 {
364 	unsigned int i;
365 
366 	/* Unlock 1 */
367 	OUTB_DELAY(bank + 0x555, 0xaa);
368 	/* Unlock 2 */
369 	OUTB_DELAY(bank + 0x2aa, 0x55);
370 
371 	/* Sector-Erase */
372 	OUTB_DELAY(bank + 0x555, 0x80);
373 	OUTB_DELAY(bank + 0x555, 0xaa);
374 	OUTB_DELAY(bank + 0x2aa, 0x55);
375 	OUTB_DELAY(bank, 0x30);
376 
377 	if (wait_operation_complete(bank) != 0) {
378 		device_printf(dev, "flash erase timeout\n");
379 		return -1;
380 	}
381 
382 	/* Reset */
383 	OUTB_DELAY(bank, 0xf0);
384 
385 	for (i = 0; i < NVRAM_SIZE; i++) {
386 		if (bank[i] != 0xff) {
387 			device_printf(dev, "flash erase has failed\n");
388 			return -1;
389 		}
390 	}
391 	return 0;
392 }
393 
394 static int
395 write_bank(device_t dev, uint8_t *bank, uint8_t *data)
396 {
397 	unsigned int i;
398 
399 	for (i = 0; i < NVRAM_SIZE; i++) {
400 		/* Unlock 1 */
401 		OUTB_DELAY(bank + 0x555, 0xaa);
402 		/* Unlock 2 */
403 		OUTB_DELAY(bank + 0x2aa, 0x55);
404 
405 		/* Write single word */
406 		OUTB_DELAY(bank + 0x555, 0xa0);
407 		OUTB_DELAY(bank + i, data[i]);
408 		if (wait_operation_complete(bank) != 0) {
409 			device_printf(dev, "flash write timeout\n");
410 			return -1;
411 		}
412 	}
413 
414 	/* Reset */
415 	OUTB_DELAY(bank, 0xf0);
416 
417 	for (i = 0; i < NVRAM_SIZE; i++) {
418 		if (bank[i] != data[i]) {
419 			device_printf(dev, "flash write has failed\n");
420 			return -1;
421 		}
422 	}
423 	return 0;
424 }
425