xref: /openbmc/linux/drivers/mtd/maps/esb2rom.c (revision 6d99a79c)
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 <linux/slab.h>
18 #include <asm/io.h>
19 #include <linux/mtd/mtd.h>
20 #include <linux/mtd/map.h>
21 #include <linux/mtd/cfi.h>
22 #include <linux/mtd/flashchip.h>
23 #include <linux/pci.h>
24 #include <linux/pci_ids.h>
25 #include <linux/list.h>
26 
27 #define MOD_NAME KBUILD_BASENAME
28 
29 #define ADDRESS_NAME_LEN 18
30 
31 #define ROM_PROBE_STEP_SIZE (64*1024) /* 64KiB */
32 
33 #define BIOS_CNTL		0xDC
34 #define BIOS_LOCK_ENABLE	0x02
35 #define BIOS_WRITE_ENABLE	0x01
36 
37 /* This became a 16-bit register, and EN2 has disappeared */
38 #define FWH_DEC_EN1	0xD8
39 #define FWH_F8_EN	0x8000
40 #define FWH_F0_EN	0x4000
41 #define FWH_E8_EN	0x2000
42 #define FWH_E0_EN	0x1000
43 #define FWH_D8_EN	0x0800
44 #define FWH_D0_EN	0x0400
45 #define FWH_C8_EN	0x0200
46 #define FWH_C0_EN	0x0100
47 #define FWH_LEGACY_F_EN	0x0080
48 #define FWH_LEGACY_E_EN	0x0040
49 /* reserved  0x0020 and 0x0010 */
50 #define FWH_70_EN	0x0008
51 #define FWH_60_EN	0x0004
52 #define FWH_50_EN	0x0002
53 #define FWH_40_EN	0x0001
54 
55 /* these are 32-bit values */
56 #define FWH_SEL1	0xD0
57 #define FWH_SEL2	0xD4
58 
59 #define FWH_8MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
60 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
61 			 FWH_70_EN | FWH_60_EN | FWH_50_EN | FWH_40_EN)
62 
63 #define FWH_7MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
64 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
65 			 FWH_70_EN | FWH_60_EN | FWH_50_EN)
66 
67 #define FWH_6MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
68 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
69 			 FWH_70_EN | FWH_60_EN)
70 
71 #define FWH_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
72 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
73 			 FWH_70_EN)
74 
75 #define FWH_4MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
76 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN)
77 
78 #define FWH_3_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
79 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN)
80 
81 #define FWH_3MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
82 			 FWH_D8_EN | FWH_D0_EN)
83 
84 #define FWH_2_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
85 			 FWH_D8_EN)
86 
87 #define FWH_2MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN)
88 
89 #define FWH_1_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN)
90 
91 #define FWH_1MiB	(FWH_F8_EN | FWH_F0_EN)
92 
93 #define FWH_0_5MiB	(FWH_F8_EN)
94 
95 
96 struct esb2rom_window {
97 	void __iomem* virt;
98 	unsigned long phys;
99 	unsigned long size;
100 	struct list_head maps;
101 	struct resource rsrc;
102 	struct pci_dev *pdev;
103 };
104 
105 struct esb2rom_map_info {
106 	struct list_head list;
107 	struct map_info map;
108 	struct mtd_info *mtd;
109 	struct resource rsrc;
110 	char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
111 };
112 
113 static struct esb2rom_window esb2rom_window = {
114 	.maps = LIST_HEAD_INIT(esb2rom_window.maps),
115 };
116 
117 static void esb2rom_cleanup(struct esb2rom_window *window)
118 {
119 	struct esb2rom_map_info *map, *scratch;
120 	u8 byte;
121 
122 	/* Disable writes through the rom window */
123 	pci_read_config_byte(window->pdev, BIOS_CNTL, &byte);
124 	pci_write_config_byte(window->pdev, BIOS_CNTL,
125 		byte & ~BIOS_WRITE_ENABLE);
126 
127 	/* Free all of the mtd devices */
128 	list_for_each_entry_safe(map, scratch, &window->maps, list) {
129 		if (map->rsrc.parent)
130 			release_resource(&map->rsrc);
131 		mtd_device_unregister(map->mtd);
132 		map_destroy(map->mtd);
133 		list_del(&map->list);
134 		kfree(map);
135 	}
136 	if (window->rsrc.parent)
137 		release_resource(&window->rsrc);
138 	if (window->virt) {
139 		iounmap(window->virt);
140 		window->virt = NULL;
141 		window->phys = 0;
142 		window->size = 0;
143 	}
144 	pci_dev_put(window->pdev);
145 }
146 
147 static int __init esb2rom_init_one(struct pci_dev *pdev,
148 				   const struct pci_device_id *ent)
149 {
150 	static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
151 	struct esb2rom_window *window = &esb2rom_window;
152 	struct esb2rom_map_info *map = NULL;
153 	unsigned long map_top;
154 	u8 byte;
155 	u16 word;
156 
157 	/* For now I just handle the ecb2 and I assume there
158 	 * are not a lot of resources up at the top of the address
159 	 * space.  It is possible to handle other devices in the
160 	 * top 16MiB but it is very painful.  Also since
161 	 * you can only really attach a FWH to an ICHX there
162 	 * a number of simplifications you can make.
163 	 *
164 	 * Also you can page firmware hubs if an 8MiB window isn't enough
165 	 * but don't currently handle that case either.
166 	 */
167 	window->pdev = pci_dev_get(pdev);
168 
169 	/* RLG:  experiment 2.  Force the window registers to the widest values */
170 
171 /*
172 	pci_read_config_word(pdev, FWH_DEC_EN1, &word);
173 	printk(KERN_DEBUG "Original FWH_DEC_EN1 : %x\n", word);
174 	pci_write_config_byte(pdev, FWH_DEC_EN1, 0xff);
175 	pci_read_config_byte(pdev, FWH_DEC_EN1, &byte);
176 	printk(KERN_DEBUG "New FWH_DEC_EN1 : %x\n", byte);
177 
178 	pci_read_config_byte(pdev, FWH_DEC_EN2, &byte);
179 	printk(KERN_DEBUG "Original FWH_DEC_EN2 : %x\n", byte);
180 	pci_write_config_byte(pdev, FWH_DEC_EN2, 0x0f);
181 	pci_read_config_byte(pdev, FWH_DEC_EN2, &byte);
182 	printk(KERN_DEBUG "New FWH_DEC_EN2 : %x\n", byte);
183 */
184 
185 	/* Find a region continuous to the end of the ROM window  */
186 	window->phys = 0;
187 	pci_read_config_word(pdev, FWH_DEC_EN1, &word);
188 	printk(KERN_DEBUG "pci_read_config_word : %x\n", word);
189 
190 	if ((word & FWH_8MiB) == FWH_8MiB)
191 		window->phys = 0xff400000;
192 	else if ((word & FWH_7MiB) == FWH_7MiB)
193 		window->phys = 0xff500000;
194 	else if ((word & FWH_6MiB) == FWH_6MiB)
195 		window->phys = 0xff600000;
196 	else if ((word & FWH_5MiB) == FWH_5MiB)
197 		window->phys = 0xFF700000;
198 	else if ((word & FWH_4MiB) == FWH_4MiB)
199 		window->phys = 0xffc00000;
200 	else if ((word & FWH_3_5MiB) == FWH_3_5MiB)
201 		window->phys = 0xffc80000;
202 	else if ((word & FWH_3MiB) == FWH_3MiB)
203 		window->phys = 0xffd00000;
204 	else if ((word & FWH_2_5MiB) == FWH_2_5MiB)
205 		window->phys = 0xffd80000;
206 	else if ((word & FWH_2MiB) == FWH_2MiB)
207 		window->phys = 0xffe00000;
208 	else if ((word & FWH_1_5MiB) == FWH_1_5MiB)
209 		window->phys = 0xffe80000;
210 	else if ((word & FWH_1MiB) == FWH_1MiB)
211 		window->phys = 0xfff00000;
212 	else if ((word & FWH_0_5MiB) == FWH_0_5MiB)
213 		window->phys = 0xfff80000;
214 
215 	if (window->phys == 0) {
216 		printk(KERN_ERR MOD_NAME ": Rom window is closed\n");
217 		goto out;
218 	}
219 
220 	/* reserved  0x0020 and 0x0010 */
221 	window->phys -= 0x400000UL;
222 	window->size = (0xffffffffUL - window->phys) + 1UL;
223 
224 	/* Enable writes through the rom window */
225 	pci_read_config_byte(pdev, BIOS_CNTL, &byte);
226 	if (!(byte & BIOS_WRITE_ENABLE)  && (byte & (BIOS_LOCK_ENABLE))) {
227 		/* The BIOS will generate an error if I enable
228 		 * this device, so don't even try.
229 		 */
230 		printk(KERN_ERR MOD_NAME ": firmware access control, I can't enable writes\n");
231 		goto out;
232 	}
233 	pci_write_config_byte(pdev, BIOS_CNTL, byte | BIOS_WRITE_ENABLE);
234 
235 	/*
236 	 * Try to reserve the window mem region.  If this fails then
237 	 * it is likely due to the window being "reserved" by the BIOS.
238 	 */
239 	window->rsrc.name = MOD_NAME;
240 	window->rsrc.start = window->phys;
241 	window->rsrc.end   = window->phys + window->size - 1;
242 	window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
243 	if (request_resource(&iomem_resource, &window->rsrc)) {
244 		window->rsrc.parent = NULL;
245 		printk(KERN_DEBUG MOD_NAME ": "
246 		       "%s(): Unable to register resource %pR - kernel bug?\n",
247 			__func__, &window->rsrc);
248 	}
249 
250 	/* Map the firmware hub into my address space. */
251 	window->virt = ioremap_nocache(window->phys, window->size);
252 	if (!window->virt) {
253 		printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
254 			window->phys, window->size);
255 		goto out;
256 	}
257 
258 	/* Get the first address to look for an rom chip at */
259 	map_top = window->phys;
260 	if ((window->phys & 0x3fffff) != 0) {
261 		/* if not aligned on 4MiB, look 4MiB lower in address space */
262 		map_top = window->phys + 0x400000;
263 	}
264 #if 1
265 	/* The probe sequence run over the firmware hub lock
266 	 * registers sets them to 0x7 (no access).
267 	 * (Insane hardware design, but most copied Intel's.)
268 	 * ==> Probe at most the last 4M of the address space.
269 	 */
270 	if (map_top < 0xffc00000)
271 		map_top = 0xffc00000;
272 #endif
273 	/* Loop through and look for rom chips */
274 	while ((map_top - 1) < 0xffffffffUL) {
275 		struct cfi_private *cfi;
276 		unsigned long offset;
277 		int i;
278 
279 		if (!map)
280 			map = kmalloc(sizeof(*map), GFP_KERNEL);
281 		if (!map) {
282 			printk(KERN_ERR MOD_NAME ": kmalloc failed");
283 			goto out;
284 		}
285 		memset(map, 0, sizeof(*map));
286 		INIT_LIST_HEAD(&map->list);
287 		map->map.name = map->map_name;
288 		map->map.phys = map_top;
289 		offset = map_top - window->phys;
290 		map->map.virt = (void __iomem *)
291 			(((unsigned long)(window->virt)) + offset);
292 		map->map.size = 0xffffffffUL - map_top + 1UL;
293 		/* Set the name of the map to the address I am trying */
294 		sprintf(map->map_name, "%s @%08Lx",
295 			MOD_NAME, (unsigned long long)map->map.phys);
296 
297 		/* Firmware hubs only use vpp when being programmed
298 		 * in a factory setting.  So in-place programming
299 		 * needs to use a different method.
300 		 */
301 		for(map->map.bankwidth = 32; map->map.bankwidth;
302 			map->map.bankwidth >>= 1) {
303 			char **probe_type;
304 			/* Skip bankwidths that are not supported */
305 			if (!map_bankwidth_supported(map->map.bankwidth))
306 				continue;
307 
308 			/* Setup the map methods */
309 			simple_map_init(&map->map);
310 
311 			/* Try all of the probe methods */
312 			probe_type = rom_probe_types;
313 			for(; *probe_type; probe_type++) {
314 				map->mtd = do_map_probe(*probe_type, &map->map);
315 				if (map->mtd)
316 					goto found;
317 			}
318 		}
319 		map_top += ROM_PROBE_STEP_SIZE;
320 		continue;
321 	found:
322 		/* Trim the size if we are larger than the map */
323 		if (map->mtd->size > map->map.size) {
324 			printk(KERN_WARNING MOD_NAME
325 				" rom(%llu) larger than window(%lu). fixing...\n",
326 				(unsigned long long)map->mtd->size, map->map.size);
327 			map->mtd->size = map->map.size;
328 		}
329 		if (window->rsrc.parent) {
330 			/*
331 			 * Registering the MTD device in iomem may not be possible
332 			 * if there is a BIOS "reserved" and BUSY range.  If this
333 			 * fails then continue anyway.
334 			 */
335 			map->rsrc.name  = map->map_name;
336 			map->rsrc.start = map->map.phys;
337 			map->rsrc.end   = map->map.phys + map->mtd->size - 1;
338 			map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
339 			if (request_resource(&window->rsrc, &map->rsrc)) {
340 				printk(KERN_ERR MOD_NAME
341 					": cannot reserve MTD resource\n");
342 				map->rsrc.parent = NULL;
343 			}
344 		}
345 
346 		/* Make the whole region visible in the map */
347 		map->map.virt = window->virt;
348 		map->map.phys = window->phys;
349 		cfi = map->map.fldrv_priv;
350 		for(i = 0; i < cfi->numchips; i++)
351 			cfi->chips[i].start += offset;
352 
353 		/* Now that the mtd devices is complete claim and export it */
354 		map->mtd->owner = THIS_MODULE;
355 		if (mtd_device_register(map->mtd, NULL, 0)) {
356 			map_destroy(map->mtd);
357 			map->mtd = NULL;
358 			goto out;
359 		}
360 
361 		/* Calculate the new value of map_top */
362 		map_top += map->mtd->size;
363 
364 		/* File away the map structure */
365 		list_add(&map->list, &window->maps);
366 		map = NULL;
367 	}
368 
369  out:
370 	/* Free any left over map structures */
371 	kfree(map);
372 
373 	/* See if I have any map structures */
374 	if (list_empty(&window->maps)) {
375 		esb2rom_cleanup(window);
376 		return -ENODEV;
377 	}
378 	return 0;
379 }
380 
381 static void esb2rom_remove_one(struct pci_dev *pdev)
382 {
383 	struct esb2rom_window *window = &esb2rom_window;
384 	esb2rom_cleanup(window);
385 }
386 
387 static const struct pci_device_id esb2rom_pci_tbl[] = {
388 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_0,
389 	  PCI_ANY_ID, PCI_ANY_ID, },
390 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_0,
391 	  PCI_ANY_ID, PCI_ANY_ID, },
392 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0,
393 	  PCI_ANY_ID, PCI_ANY_ID, },
394 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0,
395 	  PCI_ANY_ID, PCI_ANY_ID, },
396 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_1,
397 	  PCI_ANY_ID, PCI_ANY_ID, },
398 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB2_0,
399 	  PCI_ANY_ID, PCI_ANY_ID, },
400 	{ 0, },
401 };
402 
403 #if 0
404 MODULE_DEVICE_TABLE(pci, esb2rom_pci_tbl);
405 
406 static struct pci_driver esb2rom_driver = {
407 	.name =		MOD_NAME,
408 	.id_table =	esb2rom_pci_tbl,
409 	.probe =	esb2rom_init_one,
410 	.remove =	esb2rom_remove_one,
411 };
412 #endif
413 
414 static int __init init_esb2rom(void)
415 {
416 	struct pci_dev *pdev;
417 	const struct pci_device_id *id;
418 	int retVal;
419 
420 	pdev = NULL;
421 	for (id = esb2rom_pci_tbl; id->vendor; id++) {
422 		printk(KERN_DEBUG "device id = %x\n", id->device);
423 		pdev = pci_get_device(id->vendor, id->device, NULL);
424 		if (pdev) {
425 			printk(KERN_DEBUG "matched device = %x\n", id->device);
426 			break;
427 		}
428 	}
429 	if (pdev) {
430 		printk(KERN_DEBUG "matched device id %x\n", id->device);
431 		retVal = esb2rom_init_one(pdev, &esb2rom_pci_tbl[0]);
432 		pci_dev_put(pdev);
433 		printk(KERN_DEBUG "retVal = %d\n", retVal);
434 		return retVal;
435 	}
436 	return -ENXIO;
437 #if 0
438 	return pci_register_driver(&esb2rom_driver);
439 #endif
440 }
441 
442 static void __exit cleanup_esb2rom(void)
443 {
444 	esb2rom_remove_one(esb2rom_window.pdev);
445 }
446 
447 module_init(init_esb2rom);
448 module_exit(cleanup_esb2rom);
449 
450 MODULE_LICENSE("GPL");
451 MODULE_AUTHOR("Lew Glendenning <lglendenning@lnxi.com>");
452 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the ESB2 southbridge");
453