xref: /linux/drivers/mtd/maps/amd76xrom.c (revision c9895ed5a84dc3cbc86a9d6d5656d8c187f53380)
1 /*
2  * amd76xrom.c
3  *
4  * Normal mappings of chips in physical memory
5  */
6 
7 #include <linux/module.h>
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/slab.h>
12 #include <asm/io.h>
13 #include <linux/mtd/mtd.h>
14 #include <linux/mtd/map.h>
15 #include <linux/mtd/cfi.h>
16 #include <linux/mtd/flashchip.h>
17 #include <linux/pci.h>
18 #include <linux/pci_ids.h>
19 #include <linux/list.h>
20 
21 
22 #define xstr(s) str(s)
23 #define str(s) #s
24 #define MOD_NAME xstr(KBUILD_BASENAME)
25 
26 #define ADDRESS_NAME_LEN 18
27 
28 #define ROM_PROBE_STEP_SIZE (64*1024) /* 64KiB */
29 
30 struct amd76xrom_window {
31 	void __iomem *virt;
32 	unsigned long phys;
33 	unsigned long size;
34 	struct list_head maps;
35 	struct resource rsrc;
36 	struct pci_dev *pdev;
37 };
38 
39 struct amd76xrom_map_info {
40 	struct list_head list;
41 	struct map_info map;
42 	struct mtd_info *mtd;
43 	struct resource rsrc;
44 	char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
45 };
46 
47 /* The 2 bits controlling the window size are often set to allow reading
48  * the BIOS, but too small to allow writing, since the lock registers are
49  * 4MiB lower in the address space than the data.
50  *
51  * This is intended to prevent flashing the bios, perhaps accidentally.
52  *
53  * This parameter allows the normal driver to over-ride the BIOS settings.
54  *
55  * The bits are 6 and 7.  If both bits are set, it is a 5MiB window.
56  * If only the 7 Bit is set, it is a 4MiB window.  Otherwise, a
57  * 64KiB window.
58  *
59  */
60 static uint win_size_bits;
61 module_param(win_size_bits, uint, 0);
62 MODULE_PARM_DESC(win_size_bits, "ROM window size bits override for 0x43 byte, normally set by BIOS.");
63 
64 static struct amd76xrom_window amd76xrom_window = {
65 	.maps = LIST_HEAD_INIT(amd76xrom_window.maps),
66 };
67 
68 static void amd76xrom_cleanup(struct amd76xrom_window *window)
69 {
70 	struct amd76xrom_map_info *map, *scratch;
71 	u8 byte;
72 
73 	if (window->pdev) {
74 		/* Disable writes through the rom window */
75 		pci_read_config_byte(window->pdev, 0x40, &byte);
76 		pci_write_config_byte(window->pdev, 0x40, byte & ~1);
77 		pci_dev_put(window->pdev);
78 	}
79 
80 	/* Free all of the mtd devices */
81 	list_for_each_entry_safe(map, scratch, &window->maps, list) {
82 		if (map->rsrc.parent) {
83 			release_resource(&map->rsrc);
84 		}
85 		del_mtd_device(map->mtd);
86 		map_destroy(map->mtd);
87 		list_del(&map->list);
88 		kfree(map);
89 	}
90 	if (window->rsrc.parent)
91 		release_resource(&window->rsrc);
92 
93 	if (window->virt) {
94 		iounmap(window->virt);
95 		window->virt = NULL;
96 		window->phys = 0;
97 		window->size = 0;
98 		window->pdev = NULL;
99 	}
100 }
101 
102 
103 static int __devinit amd76xrom_init_one (struct pci_dev *pdev,
104 	const struct pci_device_id *ent)
105 {
106 	static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
107 	u8 byte;
108 	struct amd76xrom_window *window = &amd76xrom_window;
109 	struct amd76xrom_map_info *map = NULL;
110 	unsigned long map_top;
111 
112 	/* Remember the pci dev I find the window in - already have a ref */
113 	window->pdev = pdev;
114 
115 	/* Enable the selected rom window.  This is often incorrectly
116 	 * set up by the BIOS, and the 4MiB offset for the lock registers
117 	 * requires the full 5MiB of window space.
118 	 *
119 	 * This 'write, then read' approach leaves the bits for
120 	 * other uses of the hardware info.
121 	 */
122 	pci_read_config_byte(pdev, 0x43, &byte);
123 	pci_write_config_byte(pdev, 0x43, byte | win_size_bits );
124 
125 	/* Assume the rom window is properly setup, and find it's size */
126 	pci_read_config_byte(pdev, 0x43, &byte);
127 	if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6))) {
128 		window->phys = 0xffb00000; /* 5MiB */
129 	}
130 	else if ((byte & (1<<7)) == (1<<7)) {
131 		window->phys = 0xffc00000; /* 4MiB */
132 	}
133 	else {
134 		window->phys = 0xffff0000; /* 64KiB */
135 	}
136 	window->size = 0xffffffffUL - window->phys + 1UL;
137 
138 	/*
139 	 * Try to reserve the window mem region.  If this fails then
140 	 * it is likely due to a fragment of the window being
141 	 * "reseved" by the BIOS.  In the case that the
142 	 * request_mem_region() fails then once the rom size is
143 	 * discovered we will try to reserve the unreserved fragment.
144 	 */
145 	window->rsrc.name = MOD_NAME;
146 	window->rsrc.start = window->phys;
147 	window->rsrc.end   = window->phys + window->size - 1;
148 	window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
149 	if (request_resource(&iomem_resource, &window->rsrc)) {
150 		window->rsrc.parent = NULL;
151 		printk(KERN_ERR MOD_NAME
152 		       " %s(): Unable to register resource %pR - kernel bug?\n",
153 		       __func__, &window->rsrc);
154 	}
155 
156 
157 	/* Enable writes through the rom window */
158 	pci_read_config_byte(pdev, 0x40, &byte);
159 	pci_write_config_byte(pdev, 0x40, byte | 1);
160 
161 	/* FIXME handle registers 0x80 - 0x8C the bios region locks */
162 
163 	/* For write accesses caches are useless */
164 	window->virt = ioremap_nocache(window->phys, window->size);
165 	if (!window->virt) {
166 		printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
167 			window->phys, window->size);
168 		goto out;
169 	}
170 
171 	/* Get the first address to look for an rom chip at */
172 	map_top = window->phys;
173 #if 1
174 	/* The probe sequence run over the firmware hub lock
175 	 * registers sets them to 0x7 (no access).
176 	 * Probe at most the last 4M of the address space.
177 	 */
178 	if (map_top < 0xffc00000) {
179 		map_top = 0xffc00000;
180 	}
181 #endif
182 	/* Loop  through and look for rom chips */
183 	while((map_top - 1) < 0xffffffffUL) {
184 		struct cfi_private *cfi;
185 		unsigned long offset;
186 		int i;
187 
188 		if (!map) {
189 			map = kmalloc(sizeof(*map), GFP_KERNEL);
190 		}
191 		if (!map) {
192 			printk(KERN_ERR MOD_NAME ": kmalloc failed");
193 			goto out;
194 		}
195 		memset(map, 0, sizeof(*map));
196 		INIT_LIST_HEAD(&map->list);
197 		map->map.name = map->map_name;
198 		map->map.phys = map_top;
199 		offset = map_top - window->phys;
200 		map->map.virt = (void __iomem *)
201 			(((unsigned long)(window->virt)) + offset);
202 		map->map.size = 0xffffffffUL - map_top + 1UL;
203 		/* Set the name of the map to the address I am trying */
204 		sprintf(map->map_name, "%s @%08Lx",
205 			MOD_NAME, (unsigned long long)map->map.phys);
206 
207 		/* There is no generic VPP support */
208 		for(map->map.bankwidth = 32; map->map.bankwidth;
209 			map->map.bankwidth >>= 1)
210 		{
211 			char **probe_type;
212 			/* Skip bankwidths that are not supported */
213 			if (!map_bankwidth_supported(map->map.bankwidth))
214 				continue;
215 
216 			/* Setup the map methods */
217 			simple_map_init(&map->map);
218 
219 			/* Try all of the probe methods */
220 			probe_type = rom_probe_types;
221 			for(; *probe_type; probe_type++) {
222 				map->mtd = do_map_probe(*probe_type, &map->map);
223 				if (map->mtd)
224 					goto found;
225 			}
226 		}
227 		map_top += ROM_PROBE_STEP_SIZE;
228 		continue;
229 	found:
230 		/* Trim the size if we are larger than the map */
231 		if (map->mtd->size > map->map.size) {
232 			printk(KERN_WARNING MOD_NAME
233 				" rom(%llu) larger than window(%lu). fixing...\n",
234 				(unsigned long long)map->mtd->size, map->map.size);
235 			map->mtd->size = map->map.size;
236 		}
237 		if (window->rsrc.parent) {
238 			/*
239 			 * Registering the MTD device in iomem may not be possible
240 			 * if there is a BIOS "reserved" and BUSY range.  If this
241 			 * fails then continue anyway.
242 			 */
243 			map->rsrc.name  = map->map_name;
244 			map->rsrc.start = map->map.phys;
245 			map->rsrc.end   = map->map.phys + map->mtd->size - 1;
246 			map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
247 			if (request_resource(&window->rsrc, &map->rsrc)) {
248 				printk(KERN_ERR MOD_NAME
249 					": cannot reserve MTD resource\n");
250 				map->rsrc.parent = NULL;
251 			}
252 		}
253 
254 		/* Make the whole region visible in the map */
255 		map->map.virt = window->virt;
256 		map->map.phys = window->phys;
257 		cfi = map->map.fldrv_priv;
258 		for(i = 0; i < cfi->numchips; i++) {
259 			cfi->chips[i].start += offset;
260 		}
261 
262 		/* Now that the mtd devices is complete claim and export it */
263 		map->mtd->owner = THIS_MODULE;
264 		if (add_mtd_device(map->mtd)) {
265 			map_destroy(map->mtd);
266 			map->mtd = NULL;
267 			goto out;
268 		}
269 
270 
271 		/* Calculate the new value of map_top */
272 		map_top += map->mtd->size;
273 
274 		/* File away the map structure */
275 		list_add(&map->list, &window->maps);
276 		map = NULL;
277 	}
278 
279  out:
280 	/* Free any left over map structures */
281 	kfree(map);
282 	/* See if I have any map structures */
283 	if (list_empty(&window->maps)) {
284 		amd76xrom_cleanup(window);
285 		return -ENODEV;
286 	}
287 	return 0;
288 }
289 
290 
291 static void __devexit amd76xrom_remove_one (struct pci_dev *pdev)
292 {
293 	struct amd76xrom_window *window = &amd76xrom_window;
294 
295 	amd76xrom_cleanup(window);
296 }
297 
298 static struct pci_device_id amd76xrom_pci_tbl[] = {
299 	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7410,
300 		PCI_ANY_ID, PCI_ANY_ID, },
301 	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7440,
302 		PCI_ANY_ID, PCI_ANY_ID, },
303 	{ PCI_VENDOR_ID_AMD, 0x7468 }, /* amd8111 support */
304 	{ 0, }
305 };
306 
307 MODULE_DEVICE_TABLE(pci, amd76xrom_pci_tbl);
308 
309 #if 0
310 static struct pci_driver amd76xrom_driver = {
311 	.name =		MOD_NAME,
312 	.id_table =	amd76xrom_pci_tbl,
313 	.probe =	amd76xrom_init_one,
314 	.remove =	amd76xrom_remove_one,
315 };
316 #endif
317 
318 static int __init init_amd76xrom(void)
319 {
320 	struct pci_dev *pdev;
321 	struct pci_device_id *id;
322 	pdev = NULL;
323 	for(id = amd76xrom_pci_tbl; id->vendor; id++) {
324 		pdev = pci_get_device(id->vendor, id->device, NULL);
325 		if (pdev) {
326 			break;
327 		}
328 	}
329 	if (pdev) {
330 		return amd76xrom_init_one(pdev, &amd76xrom_pci_tbl[0]);
331 	}
332 	return -ENXIO;
333 #if 0
334 	return pci_register_driver(&amd76xrom_driver);
335 #endif
336 }
337 
338 static void __exit cleanup_amd76xrom(void)
339 {
340 	amd76xrom_remove_one(amd76xrom_window.pdev);
341 }
342 
343 module_init(init_amd76xrom);
344 module_exit(cleanup_amd76xrom);
345 
346 MODULE_LICENSE("GPL");
347 MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>");
348 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the AMD76X southbridge");
349 
350