xref: /openbmc/linux/drivers/mtd/maps/esb2rom.c (revision 7dd65feb)
1 /*
2  * esb2rom.c
3  *
4  * Normal mappings of flash chips in physical memory
5  * through the Intel ESB2 Southbridge.
6  *
7  * This was derived from ichxrom.c in May 2006 by
8  *	Lew Glendenning <lglendenning@lnxi.com>
9  *
10  * Eric Biederman, of course, was a major help in this effort.
11  */
12 
13 #include <linux/module.h>
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <asm/io.h>
18 #include <linux/mtd/mtd.h>
19 #include <linux/mtd/map.h>
20 #include <linux/mtd/cfi.h>
21 #include <linux/mtd/flashchip.h>
22 #include <linux/pci.h>
23 #include <linux/pci_ids.h>
24 #include <linux/list.h>
25 
26 #define MOD_NAME KBUILD_BASENAME
27 
28 #define ADDRESS_NAME_LEN 18
29 
30 #define ROM_PROBE_STEP_SIZE (64*1024) /* 64KiB */
31 
32 #define BIOS_CNTL		0xDC
33 #define BIOS_LOCK_ENABLE	0x02
34 #define BIOS_WRITE_ENABLE	0x01
35 
36 /* This became a 16-bit register, and EN2 has disappeared */
37 #define FWH_DEC_EN1	0xD8
38 #define FWH_F8_EN	0x8000
39 #define FWH_F0_EN	0x4000
40 #define FWH_E8_EN	0x2000
41 #define FWH_E0_EN	0x1000
42 #define FWH_D8_EN	0x0800
43 #define FWH_D0_EN	0x0400
44 #define FWH_C8_EN	0x0200
45 #define FWH_C0_EN	0x0100
46 #define FWH_LEGACY_F_EN	0x0080
47 #define FWH_LEGACY_E_EN	0x0040
48 /* reserved  0x0020 and 0x0010 */
49 #define FWH_70_EN	0x0008
50 #define FWH_60_EN	0x0004
51 #define FWH_50_EN	0x0002
52 #define FWH_40_EN	0x0001
53 
54 /* these are 32-bit values */
55 #define FWH_SEL1	0xD0
56 #define FWH_SEL2	0xD4
57 
58 #define FWH_8MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
59 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
60 			 FWH_70_EN | FWH_60_EN | FWH_50_EN | FWH_40_EN)
61 
62 #define FWH_7MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
63 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
64 			 FWH_70_EN | FWH_60_EN | FWH_50_EN)
65 
66 #define FWH_6MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
67 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
68 			 FWH_70_EN | FWH_60_EN)
69 
70 #define FWH_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
71 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
72 			 FWH_70_EN)
73 
74 #define FWH_4MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
75 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN)
76 
77 #define FWH_3_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
78 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN)
79 
80 #define FWH_3MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
81 			 FWH_D8_EN | FWH_D0_EN)
82 
83 #define FWH_2_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
84 			 FWH_D8_EN)
85 
86 #define FWH_2MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN)
87 
88 #define FWH_1_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN)
89 
90 #define FWH_1MiB	(FWH_F8_EN | FWH_F0_EN)
91 
92 #define FWH_0_5MiB	(FWH_F8_EN)
93 
94 
95 struct esb2rom_window {
96 	void __iomem* virt;
97 	unsigned long phys;
98 	unsigned long size;
99 	struct list_head maps;
100 	struct resource rsrc;
101 	struct pci_dev *pdev;
102 };
103 
104 struct esb2rom_map_info {
105 	struct list_head list;
106 	struct map_info map;
107 	struct mtd_info *mtd;
108 	struct resource rsrc;
109 	char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
110 };
111 
112 static struct esb2rom_window esb2rom_window = {
113 	.maps = LIST_HEAD_INIT(esb2rom_window.maps),
114 };
115 
116 static void esb2rom_cleanup(struct esb2rom_window *window)
117 {
118 	struct esb2rom_map_info *map, *scratch;
119 	u8 byte;
120 
121 	/* Disable writes through the rom window */
122 	pci_read_config_byte(window->pdev, BIOS_CNTL, &byte);
123 	pci_write_config_byte(window->pdev, BIOS_CNTL,
124 		byte & ~BIOS_WRITE_ENABLE);
125 
126 	/* Free all of the mtd devices */
127 	list_for_each_entry_safe(map, scratch, &window->maps, list) {
128 		if (map->rsrc.parent)
129 			release_resource(&map->rsrc);
130 		del_mtd_device(map->mtd);
131 		map_destroy(map->mtd);
132 		list_del(&map->list);
133 		kfree(map);
134 	}
135 	if (window->rsrc.parent)
136 		release_resource(&window->rsrc);
137 	if (window->virt) {
138 		iounmap(window->virt);
139 		window->virt = NULL;
140 		window->phys = 0;
141 		window->size = 0;
142 	}
143 	pci_dev_put(window->pdev);
144 }
145 
146 static int __devinit esb2rom_init_one(struct pci_dev *pdev,
147 				      const struct pci_device_id *ent)
148 {
149 	static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
150 	struct esb2rom_window *window = &esb2rom_window;
151 	struct esb2rom_map_info *map = NULL;
152 	unsigned long map_top;
153 	u8 byte;
154 	u16 word;
155 
156 	/* For now I just handle the ecb2 and I assume there
157 	 * are not a lot of resources up at the top of the address
158 	 * space.  It is possible to handle other devices in the
159 	 * top 16MiB but it is very painful.  Also since
160 	 * you can only really attach a FWH to an ICHX there
161 	 * a number of simplifications you can make.
162 	 *
163 	 * Also you can page firmware hubs if an 8MiB window isn't enough
164 	 * but don't currently handle that case either.
165 	 */
166 	window->pdev = pci_dev_get(pdev);
167 
168 	/* RLG:  experiment 2.  Force the window registers to the widest values */
169 
170 /*
171 	pci_read_config_word(pdev, FWH_DEC_EN1, &word);
172 	printk(KERN_DEBUG "Original FWH_DEC_EN1 : %x\n", word);
173 	pci_write_config_byte(pdev, FWH_DEC_EN1, 0xff);
174 	pci_read_config_byte(pdev, FWH_DEC_EN1, &byte);
175 	printk(KERN_DEBUG "New FWH_DEC_EN1 : %x\n", byte);
176 
177 	pci_read_config_byte(pdev, FWH_DEC_EN2, &byte);
178 	printk(KERN_DEBUG "Original FWH_DEC_EN2 : %x\n", byte);
179 	pci_write_config_byte(pdev, FWH_DEC_EN2, 0x0f);
180 	pci_read_config_byte(pdev, FWH_DEC_EN2, &byte);
181 	printk(KERN_DEBUG "New FWH_DEC_EN2 : %x\n", byte);
182 */
183 
184 	/* Find a region continuous to the end of the ROM window  */
185 	window->phys = 0;
186 	pci_read_config_word(pdev, FWH_DEC_EN1, &word);
187 	printk(KERN_DEBUG "pci_read_config_word : %x\n", word);
188 
189 	if ((word & FWH_8MiB) == FWH_8MiB)
190 		window->phys = 0xff400000;
191 	else if ((word & FWH_7MiB) == FWH_7MiB)
192 		window->phys = 0xff500000;
193 	else if ((word & FWH_6MiB) == FWH_6MiB)
194 		window->phys = 0xff600000;
195 	else if ((word & FWH_5MiB) == FWH_5MiB)
196 		window->phys = 0xFF700000;
197 	else if ((word & FWH_4MiB) == FWH_4MiB)
198 		window->phys = 0xffc00000;
199 	else if ((word & FWH_3_5MiB) == FWH_3_5MiB)
200 		window->phys = 0xffc80000;
201 	else if ((word & FWH_3MiB) == FWH_3MiB)
202 		window->phys = 0xffd00000;
203 	else if ((word & FWH_2_5MiB) == FWH_2_5MiB)
204 		window->phys = 0xffd80000;
205 	else if ((word & FWH_2MiB) == FWH_2MiB)
206 		window->phys = 0xffe00000;
207 	else if ((word & FWH_1_5MiB) == FWH_1_5MiB)
208 		window->phys = 0xffe80000;
209 	else if ((word & FWH_1MiB) == FWH_1MiB)
210 		window->phys = 0xfff00000;
211 	else if ((word & FWH_0_5MiB) == FWH_0_5MiB)
212 		window->phys = 0xfff80000;
213 
214 	if (window->phys == 0) {
215 		printk(KERN_ERR MOD_NAME ": Rom window is closed\n");
216 		goto out;
217 	}
218 
219 	/* reserved  0x0020 and 0x0010 */
220 	window->phys -= 0x400000UL;
221 	window->size = (0xffffffffUL - window->phys) + 1UL;
222 
223 	/* Enable writes through the rom window */
224 	pci_read_config_byte(pdev, BIOS_CNTL, &byte);
225 	if (!(byte & BIOS_WRITE_ENABLE)  && (byte & (BIOS_LOCK_ENABLE))) {
226 		/* The BIOS will generate an error if I enable
227 		 * this device, so don't even try.
228 		 */
229 		printk(KERN_ERR MOD_NAME ": firmware access control, I can't enable writes\n");
230 		goto out;
231 	}
232 	pci_write_config_byte(pdev, BIOS_CNTL, byte | BIOS_WRITE_ENABLE);
233 
234 	/*
235 	 * Try to reserve the window mem region.  If this fails then
236 	 * it is likely due to the window being "reseved" by the BIOS.
237 	 */
238 	window->rsrc.name = MOD_NAME;
239 	window->rsrc.start = window->phys;
240 	window->rsrc.end   = window->phys + window->size - 1;
241 	window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
242 	if (request_resource(&iomem_resource, &window->rsrc)) {
243 		window->rsrc.parent = NULL;
244 		printk(KERN_DEBUG MOD_NAME
245 			": %s(): Unable to register resource"
246 			" 0x%.08llx-0x%.08llx - kernel bug?\n",
247 			__func__,
248 			(unsigned long long)window->rsrc.start,
249 			(unsigned long long)window->rsrc.end);
250 	}
251 
252 	/* Map the firmware hub into my address space. */
253 	window->virt = ioremap_nocache(window->phys, window->size);
254 	if (!window->virt) {
255 		printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
256 			window->phys, window->size);
257 		goto out;
258 	}
259 
260 	/* Get the first address to look for an rom chip at */
261 	map_top = window->phys;
262 	if ((window->phys & 0x3fffff) != 0) {
263 		/* if not aligned on 4MiB, look 4MiB lower in address space */
264 		map_top = window->phys + 0x400000;
265 	}
266 #if 1
267 	/* The probe sequence run over the firmware hub lock
268 	 * registers sets them to 0x7 (no access).
269 	 * (Insane hardware design, but most copied Intel's.)
270 	 * ==> Probe at most the last 4M of the address space.
271 	 */
272 	if (map_top < 0xffc00000)
273 		map_top = 0xffc00000;
274 #endif
275 	/* Loop through and look for rom chips */
276 	while ((map_top - 1) < 0xffffffffUL) {
277 		struct cfi_private *cfi;
278 		unsigned long offset;
279 		int i;
280 
281 		if (!map)
282 			map = kmalloc(sizeof(*map), GFP_KERNEL);
283 		if (!map) {
284 			printk(KERN_ERR MOD_NAME ": kmalloc failed");
285 			goto out;
286 		}
287 		memset(map, 0, sizeof(*map));
288 		INIT_LIST_HEAD(&map->list);
289 		map->map.name = map->map_name;
290 		map->map.phys = map_top;
291 		offset = map_top - window->phys;
292 		map->map.virt = (void __iomem *)
293 			(((unsigned long)(window->virt)) + offset);
294 		map->map.size = 0xffffffffUL - map_top + 1UL;
295 		/* Set the name of the map to the address I am trying */
296 		sprintf(map->map_name, "%s @%08Lx",
297 			MOD_NAME, (unsigned long long)map->map.phys);
298 
299 		/* Firmware hubs only use vpp when being programmed
300 		 * in a factory setting.  So in-place programming
301 		 * needs to use a different method.
302 		 */
303 		for(map->map.bankwidth = 32; map->map.bankwidth;
304 			map->map.bankwidth >>= 1) {
305 			char **probe_type;
306 			/* Skip bankwidths that are not supported */
307 			if (!map_bankwidth_supported(map->map.bankwidth))
308 				continue;
309 
310 			/* Setup the map methods */
311 			simple_map_init(&map->map);
312 
313 			/* Try all of the probe methods */
314 			probe_type = rom_probe_types;
315 			for(; *probe_type; probe_type++) {
316 				map->mtd = do_map_probe(*probe_type, &map->map);
317 				if (map->mtd)
318 					goto found;
319 			}
320 		}
321 		map_top += ROM_PROBE_STEP_SIZE;
322 		continue;
323 	found:
324 		/* Trim the size if we are larger than the map */
325 		if (map->mtd->size > map->map.size) {
326 			printk(KERN_WARNING MOD_NAME
327 				" rom(%llu) larger than window(%lu). fixing...\n",
328 				(unsigned long long)map->mtd->size, map->map.size);
329 			map->mtd->size = map->map.size;
330 		}
331 		if (window->rsrc.parent) {
332 			/*
333 			 * Registering the MTD device in iomem may not be possible
334 			 * if there is a BIOS "reserved" and BUSY range.  If this
335 			 * fails then continue anyway.
336 			 */
337 			map->rsrc.name  = map->map_name;
338 			map->rsrc.start = map->map.phys;
339 			map->rsrc.end   = map->map.phys + map->mtd->size - 1;
340 			map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
341 			if (request_resource(&window->rsrc, &map->rsrc)) {
342 				printk(KERN_ERR MOD_NAME
343 					": cannot reserve MTD resource\n");
344 				map->rsrc.parent = NULL;
345 			}
346 		}
347 
348 		/* Make the whole region visible in the map */
349 		map->map.virt = window->virt;
350 		map->map.phys = window->phys;
351 		cfi = map->map.fldrv_priv;
352 		for(i = 0; i < cfi->numchips; i++)
353 			cfi->chips[i].start += offset;
354 
355 		/* Now that the mtd devices is complete claim and export it */
356 		map->mtd->owner = THIS_MODULE;
357 		if (add_mtd_device(map->mtd)) {
358 			map_destroy(map->mtd);
359 			map->mtd = NULL;
360 			goto out;
361 		}
362 
363 		/* Calculate the new value of map_top */
364 		map_top += map->mtd->size;
365 
366 		/* File away the map structure */
367 		list_add(&map->list, &window->maps);
368 		map = NULL;
369 	}
370 
371  out:
372 	/* Free any left over map structures */
373 	kfree(map);
374 
375 	/* See if I have any map structures */
376 	if (list_empty(&window->maps)) {
377 		esb2rom_cleanup(window);
378 		return -ENODEV;
379 	}
380 	return 0;
381 }
382 
383 static void __devexit esb2rom_remove_one (struct pci_dev *pdev)
384 {
385 	struct esb2rom_window *window = &esb2rom_window;
386 	esb2rom_cleanup(window);
387 }
388 
389 static struct pci_device_id esb2rom_pci_tbl[] __devinitdata = {
390 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_0,
391 	  PCI_ANY_ID, PCI_ANY_ID, },
392 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_0,
393 	  PCI_ANY_ID, PCI_ANY_ID, },
394 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0,
395 	  PCI_ANY_ID, PCI_ANY_ID, },
396 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0,
397 	  PCI_ANY_ID, PCI_ANY_ID, },
398 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_1,
399 	  PCI_ANY_ID, PCI_ANY_ID, },
400 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB2_0,
401 	  PCI_ANY_ID, PCI_ANY_ID, },
402 	{ 0, },
403 };
404 
405 #if 0
406 MODULE_DEVICE_TABLE(pci, esb2rom_pci_tbl);
407 
408 static struct pci_driver esb2rom_driver = {
409 	.name =		MOD_NAME,
410 	.id_table =	esb2rom_pci_tbl,
411 	.probe =	esb2rom_init_one,
412 	.remove =	esb2rom_remove_one,
413 };
414 #endif
415 
416 static int __init init_esb2rom(void)
417 {
418 	struct pci_dev *pdev;
419 	struct pci_device_id *id;
420 	int retVal;
421 
422 	pdev = NULL;
423 	for (id = esb2rom_pci_tbl; id->vendor; id++) {
424 		printk(KERN_DEBUG "device id = %x\n", id->device);
425 		pdev = pci_get_device(id->vendor, id->device, NULL);
426 		if (pdev) {
427 			printk(KERN_DEBUG "matched device = %x\n", id->device);
428 			break;
429 		}
430 	}
431 	if (pdev) {
432 		printk(KERN_DEBUG "matched device id %x\n", id->device);
433 		retVal = esb2rom_init_one(pdev, &esb2rom_pci_tbl[0]);
434 		pci_dev_put(pdev);
435 		printk(KERN_DEBUG "retVal = %d\n", retVal);
436 		return retVal;
437 	}
438 	return -ENXIO;
439 #if 0
440 	return pci_register_driver(&esb2rom_driver);
441 #endif
442 }
443 
444 static void __exit cleanup_esb2rom(void)
445 {
446 	esb2rom_remove_one(esb2rom_window.pdev);
447 }
448 
449 module_init(init_esb2rom);
450 module_exit(cleanup_esb2rom);
451 
452 MODULE_LICENSE("GPL");
453 MODULE_AUTHOR("Lew Glendenning <lglendenning@lnxi.com>");
454 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the ESB2 southbridge");
455