xref: /openbmc/linux/drivers/mtd/maps/amd76xrom.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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"
153 			" 0x%.16llx-0x%.16llx - kernel bug?\n",
154 			__func__,
155 			(unsigned long long)window->rsrc.start,
156 			(unsigned long long)window->rsrc.end);
157 	}
158 
159 
160 	/* Enable writes through the rom window */
161 	pci_read_config_byte(pdev, 0x40, &byte);
162 	pci_write_config_byte(pdev, 0x40, byte | 1);
163 
164 	/* FIXME handle registers 0x80 - 0x8C the bios region locks */
165 
166 	/* For write accesses caches are useless */
167 	window->virt = ioremap_nocache(window->phys, window->size);
168 	if (!window->virt) {
169 		printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
170 			window->phys, window->size);
171 		goto out;
172 	}
173 
174 	/* Get the first address to look for an rom chip at */
175 	map_top = window->phys;
176 #if 1
177 	/* The probe sequence run over the firmware hub lock
178 	 * registers sets them to 0x7 (no access).
179 	 * Probe at most the last 4M of the address space.
180 	 */
181 	if (map_top < 0xffc00000) {
182 		map_top = 0xffc00000;
183 	}
184 #endif
185 	/* Loop  through and look for rom chips */
186 	while((map_top - 1) < 0xffffffffUL) {
187 		struct cfi_private *cfi;
188 		unsigned long offset;
189 		int i;
190 
191 		if (!map) {
192 			map = kmalloc(sizeof(*map), GFP_KERNEL);
193 		}
194 		if (!map) {
195 			printk(KERN_ERR MOD_NAME ": kmalloc failed");
196 			goto out;
197 		}
198 		memset(map, 0, sizeof(*map));
199 		INIT_LIST_HEAD(&map->list);
200 		map->map.name = map->map_name;
201 		map->map.phys = map_top;
202 		offset = map_top - window->phys;
203 		map->map.virt = (void __iomem *)
204 			(((unsigned long)(window->virt)) + offset);
205 		map->map.size = 0xffffffffUL - map_top + 1UL;
206 		/* Set the name of the map to the address I am trying */
207 		sprintf(map->map_name, "%s @%08Lx",
208 			MOD_NAME, (unsigned long long)map->map.phys);
209 
210 		/* There is no generic VPP support */
211 		for(map->map.bankwidth = 32; map->map.bankwidth;
212 			map->map.bankwidth >>= 1)
213 		{
214 			char **probe_type;
215 			/* Skip bankwidths that are not supported */
216 			if (!map_bankwidth_supported(map->map.bankwidth))
217 				continue;
218 
219 			/* Setup the map methods */
220 			simple_map_init(&map->map);
221 
222 			/* Try all of the probe methods */
223 			probe_type = rom_probe_types;
224 			for(; *probe_type; probe_type++) {
225 				map->mtd = do_map_probe(*probe_type, &map->map);
226 				if (map->mtd)
227 					goto found;
228 			}
229 		}
230 		map_top += ROM_PROBE_STEP_SIZE;
231 		continue;
232 	found:
233 		/* Trim the size if we are larger than the map */
234 		if (map->mtd->size > map->map.size) {
235 			printk(KERN_WARNING MOD_NAME
236 				" rom(%llu) larger than window(%lu). fixing...\n",
237 				(unsigned long long)map->mtd->size, map->map.size);
238 			map->mtd->size = map->map.size;
239 		}
240 		if (window->rsrc.parent) {
241 			/*
242 			 * Registering the MTD device in iomem may not be possible
243 			 * if there is a BIOS "reserved" and BUSY range.  If this
244 			 * fails then continue anyway.
245 			 */
246 			map->rsrc.name  = map->map_name;
247 			map->rsrc.start = map->map.phys;
248 			map->rsrc.end   = map->map.phys + map->mtd->size - 1;
249 			map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
250 			if (request_resource(&window->rsrc, &map->rsrc)) {
251 				printk(KERN_ERR MOD_NAME
252 					": cannot reserve MTD resource\n");
253 				map->rsrc.parent = NULL;
254 			}
255 		}
256 
257 		/* Make the whole region visible in the map */
258 		map->map.virt = window->virt;
259 		map->map.phys = window->phys;
260 		cfi = map->map.fldrv_priv;
261 		for(i = 0; i < cfi->numchips; i++) {
262 			cfi->chips[i].start += offset;
263 		}
264 
265 		/* Now that the mtd devices is complete claim and export it */
266 		map->mtd->owner = THIS_MODULE;
267 		if (add_mtd_device(map->mtd)) {
268 			map_destroy(map->mtd);
269 			map->mtd = NULL;
270 			goto out;
271 		}
272 
273 
274 		/* Calculate the new value of map_top */
275 		map_top += map->mtd->size;
276 
277 		/* File away the map structure */
278 		list_add(&map->list, &window->maps);
279 		map = NULL;
280 	}
281 
282  out:
283 	/* Free any left over map structures */
284 	kfree(map);
285 	/* See if I have any map structures */
286 	if (list_empty(&window->maps)) {
287 		amd76xrom_cleanup(window);
288 		return -ENODEV;
289 	}
290 	return 0;
291 }
292 
293 
294 static void __devexit amd76xrom_remove_one (struct pci_dev *pdev)
295 {
296 	struct amd76xrom_window *window = &amd76xrom_window;
297 
298 	amd76xrom_cleanup(window);
299 }
300 
301 static struct pci_device_id amd76xrom_pci_tbl[] = {
302 	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7410,
303 		PCI_ANY_ID, PCI_ANY_ID, },
304 	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7440,
305 		PCI_ANY_ID, PCI_ANY_ID, },
306 	{ PCI_VENDOR_ID_AMD, 0x7468 }, /* amd8111 support */
307 	{ 0, }
308 };
309 
310 MODULE_DEVICE_TABLE(pci, amd76xrom_pci_tbl);
311 
312 #if 0
313 static struct pci_driver amd76xrom_driver = {
314 	.name =		MOD_NAME,
315 	.id_table =	amd76xrom_pci_tbl,
316 	.probe =	amd76xrom_init_one,
317 	.remove =	amd76xrom_remove_one,
318 };
319 #endif
320 
321 static int __init init_amd76xrom(void)
322 {
323 	struct pci_dev *pdev;
324 	struct pci_device_id *id;
325 	pdev = NULL;
326 	for(id = amd76xrom_pci_tbl; id->vendor; id++) {
327 		pdev = pci_get_device(id->vendor, id->device, NULL);
328 		if (pdev) {
329 			break;
330 		}
331 	}
332 	if (pdev) {
333 		return amd76xrom_init_one(pdev, &amd76xrom_pci_tbl[0]);
334 	}
335 	return -ENXIO;
336 #if 0
337 	return pci_register_driver(&amd76xrom_driver);
338 #endif
339 }
340 
341 static void __exit cleanup_amd76xrom(void)
342 {
343 	amd76xrom_remove_one(amd76xrom_window.pdev);
344 }
345 
346 module_init(init_amd76xrom);
347 module_exit(cleanup_amd76xrom);
348 
349 MODULE_LICENSE("GPL");
350 MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>");
351 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the AMD76X southbridge");
352 
353