xref: /openbmc/linux/drivers/mtd/maps/ck804xrom.c (revision 64c70b1c)
1 /*
2  * ck804xrom.c
3  *
4  * Normal mappings of chips in physical memory
5  *
6  * Dave Olsen <dolsen@lnxi.com>
7  * Ryan Jackson <rjackson@lnxi.com>
8  */
9 
10 #include <linux/module.h>
11 #include <linux/types.h>
12 #include <linux/version.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <asm/io.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/mtd/map.h>
18 #include <linux/mtd/cfi.h>
19 #include <linux/mtd/flashchip.h>
20 #include <linux/pci.h>
21 #include <linux/pci_ids.h>
22 #include <linux/list.h>
23 
24 
25 #define MOD_NAME KBUILD_BASENAME
26 
27 #define ADDRESS_NAME_LEN 18
28 
29 #define ROM_PROBE_STEP_SIZE (64*1024)
30 
31 struct ck804xrom_window {
32 	void __iomem *virt;
33 	unsigned long phys;
34 	unsigned long size;
35 	struct list_head maps;
36 	struct resource rsrc;
37 	struct pci_dev *pdev;
38 };
39 
40 struct ck804xrom_map_info {
41 	struct list_head list;
42 	struct map_info map;
43 	struct mtd_info *mtd;
44 	struct resource rsrc;
45 	char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
46 };
47 
48 
49 /* The 2 bits controlling the window size are often set to allow reading
50  * the BIOS, but too small to allow writing, since the lock registers are
51  * 4MiB lower in the address space than the data.
52  *
53  * This is intended to prevent flashing the bios, perhaps accidentally.
54  *
55  * This parameter allows the normal driver to override the BIOS settings.
56  *
57  * The bits are 6 and 7.  If both bits are set, it is a 5MiB window.
58  * If only the 7 Bit is set, it is a 4MiB window.  Otherwise, a
59  * 64KiB window.
60  *
61  */
62 static uint win_size_bits = 0;
63 module_param(win_size_bits, uint, 0);
64 MODULE_PARM_DESC(win_size_bits, "ROM window size bits override for 0x88 byte, normally set by BIOS.");
65 
66 static struct ck804xrom_window ck804xrom_window = {
67 	.maps = LIST_HEAD_INIT(ck804xrom_window.maps),
68 };
69 
70 static void ck804xrom_cleanup(struct ck804xrom_window *window)
71 {
72 	struct ck804xrom_map_info *map, *scratch;
73 	u8 byte;
74 
75 	if (window->pdev) {
76 		/* Disable writes through the rom window */
77 		pci_read_config_byte(window->pdev, 0x6d, &byte);
78 		pci_write_config_byte(window->pdev, 0x6d, byte & ~1);
79 	}
80 
81 	/* Free all of the mtd devices */
82 	list_for_each_entry_safe(map, scratch, &window->maps, list) {
83 		if (map->rsrc.parent)
84 			release_resource(&map->rsrc);
85 
86 		del_mtd_device(map->mtd);
87 		map_destroy(map->mtd);
88 		list_del(&map->list);
89 		kfree(map);
90 	}
91 	if (window->rsrc.parent)
92 		release_resource(&window->rsrc);
93 
94 	if (window->virt) {
95 		iounmap(window->virt);
96 		window->virt = NULL;
97 		window->phys = 0;
98 		window->size = 0;
99 	}
100 	pci_dev_put(window->pdev);
101 }
102 
103 
104 static int __devinit ck804xrom_init_one (struct pci_dev *pdev,
105 	const struct pci_device_id *ent)
106 {
107 	static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
108 	u8 byte;
109 	struct ck804xrom_window *window = &ck804xrom_window;
110 	struct ck804xrom_map_info *map = NULL;
111 	unsigned long map_top;
112 
113 	/* Remember the pci dev I find the window in */
114 	window->pdev = pci_dev_get(pdev);
115 
116 	/* Enable the selected rom window.  This is often incorrectly
117 	 * set up by the BIOS, and the 4MiB offset for the lock registers
118 	 * requires the full 5MiB of window space.
119 	 *
120 	 * This 'write, then read' approach leaves the bits for
121 	 * other uses of the hardware info.
122 	 */
123         pci_read_config_byte(pdev, 0x88, &byte);
124         pci_write_config_byte(pdev, 0x88, byte | win_size_bits );
125 
126 
127 	/* Assume the rom window is properly setup, and find it's size */
128 	pci_read_config_byte(pdev, 0x88, &byte);
129 
130 	if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6)))
131 		window->phys = 0xffb00000; /* 5MiB */
132 	else if ((byte & (1<<7)) == (1<<7))
133 		window->phys = 0xffc00000; /* 4MiB */
134 	else
135 		window->phys = 0xffff0000; /* 64KiB */
136 
137 	window->size = 0xffffffffUL - window->phys + 1UL;
138 
139 	/*
140 	 * Try to reserve the window mem region.  If this fails then
141 	 * it is likely due to a fragment of the window being
142 	 * "reserved" by the BIOS.  In the case that the
143 	 * request_mem_region() fails then once the rom size is
144 	 * discovered we will try to reserve the unreserved fragment.
145 	 */
146 	window->rsrc.name = MOD_NAME;
147 	window->rsrc.start = window->phys;
148 	window->rsrc.end   = window->phys + window->size - 1;
149 	window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
150 	if (request_resource(&iomem_resource, &window->rsrc)) {
151 		window->rsrc.parent = NULL;
152 		printk(KERN_ERR MOD_NAME
153 			" %s(): Unable to register resource"
154 			" 0x%.016llx-0x%.016llx - kernel bug?\n",
155 			__func__,
156 			(unsigned long long)window->rsrc.start,
157 			(unsigned long long)window->rsrc.end);
158 	}
159 
160 
161 	/* Enable writes through the rom window */
162 	pci_read_config_byte(pdev, 0x6d, &byte);
163 	pci_write_config_byte(pdev, 0x6d, byte | 1);
164 
165 	/* FIXME handle registers 0x80 - 0x8C the bios region locks */
166 
167 	/* For write accesses caches are useless */
168 	window->virt = ioremap_nocache(window->phys, window->size);
169 	if (!window->virt) {
170 		printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
171 			window->phys, window->size);
172 		goto out;
173 	}
174 
175 	/* Get the first address to look for a rom chip at */
176 	map_top = window->phys;
177 #if 1
178 	/* The probe sequence run over the firmware hub lock
179 	 * registers sets them to 0x7 (no access).
180 	 * Probe at most the last 4MiB of the address space.
181 	 */
182 	if (map_top < 0xffc00000)
183 		map_top = 0xffc00000;
184 #endif
185 	/* Loop  through and look for rom chips.  Since we don't know the
186 	 * starting address for each chip, probe every ROM_PROBE_STEP_SIZE
187 	 * bytes from the starting address of the window.
188 	 */
189 	while((map_top - 1) < 0xffffffffUL) {
190 		struct cfi_private *cfi;
191 		unsigned long offset;
192 		int i;
193 
194 		if (!map)
195 			map = kmalloc(sizeof(*map), GFP_KERNEL);
196 
197 		if (!map) {
198 			printk(KERN_ERR MOD_NAME ": kmalloc failed");
199 			goto out;
200 		}
201 		memset(map, 0, sizeof(*map));
202 		INIT_LIST_HEAD(&map->list);
203 		map->map.name = map->map_name;
204 		map->map.phys = map_top;
205 		offset = map_top - window->phys;
206 		map->map.virt = (void __iomem *)
207 			(((unsigned long)(window->virt)) + offset);
208 		map->map.size = 0xffffffffUL - map_top + 1UL;
209 		/* Set the name of the map to the address I am trying */
210 		sprintf(map->map_name, "%s @%08Lx",
211 			MOD_NAME, (unsigned long long)map->map.phys);
212 
213 		/* There is no generic VPP support */
214 		for(map->map.bankwidth = 32; map->map.bankwidth;
215 			map->map.bankwidth >>= 1)
216 		{
217 			char **probe_type;
218 			/* Skip bankwidths that are not supported */
219 			if (!map_bankwidth_supported(map->map.bankwidth))
220 				continue;
221 
222 			/* Setup the map methods */
223 			simple_map_init(&map->map);
224 
225 			/* Try all of the probe methods */
226 			probe_type = rom_probe_types;
227 			for(; *probe_type; probe_type++) {
228 				map->mtd = do_map_probe(*probe_type, &map->map);
229 				if (map->mtd)
230 					goto found;
231 			}
232 		}
233 		map_top += ROM_PROBE_STEP_SIZE;
234 		continue;
235 	found:
236 		/* Trim the size if we are larger than the map */
237 		if (map->mtd->size > map->map.size) {
238 			printk(KERN_WARNING MOD_NAME
239 				" rom(%u) larger than window(%lu). fixing...\n",
240 				map->mtd->size, map->map.size);
241 			map->mtd->size = map->map.size;
242 		}
243 		if (window->rsrc.parent) {
244 			/*
245 			 * Registering the MTD device in iomem may not be possible
246 			 * if there is a BIOS "reserved" and BUSY range.  If this
247 			 * fails then continue anyway.
248 			 */
249 			map->rsrc.name  = map->map_name;
250 			map->rsrc.start = map->map.phys;
251 			map->rsrc.end   = map->map.phys + map->mtd->size - 1;
252 			map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
253 			if (request_resource(&window->rsrc, &map->rsrc)) {
254 				printk(KERN_ERR MOD_NAME
255 					": cannot reserve MTD resource\n");
256 				map->rsrc.parent = NULL;
257 			}
258 		}
259 
260 		/* Make the whole region visible in the map */
261 		map->map.virt = window->virt;
262 		map->map.phys = window->phys;
263 		cfi = map->map.fldrv_priv;
264 		for(i = 0; i < cfi->numchips; i++)
265 			cfi->chips[i].start += offset;
266 
267 		/* Now that the mtd devices is complete claim and export it */
268 		map->mtd->owner = THIS_MODULE;
269 		if (add_mtd_device(map->mtd)) {
270 			map_destroy(map->mtd);
271 			map->mtd = NULL;
272 			goto out;
273 		}
274 
275 
276 		/* Calculate the new value of map_top */
277 		map_top += map->mtd->size;
278 
279 		/* File away the map structure */
280 		list_add(&map->list, &window->maps);
281 		map = NULL;
282 	}
283 
284  out:
285 	/* Free any left over map structures */
286 	if (map)
287 		kfree(map);
288 
289 	/* See if I have any map structures */
290 	if (list_empty(&window->maps)) {
291 		ck804xrom_cleanup(window);
292 		return -ENODEV;
293 	}
294 	return 0;
295 }
296 
297 
298 static void __devexit ck804xrom_remove_one (struct pci_dev *pdev)
299 {
300 	struct ck804xrom_window *window = &ck804xrom_window;
301 
302 	ck804xrom_cleanup(window);
303 }
304 
305 static struct pci_device_id ck804xrom_pci_tbl[] = {
306 	{ PCI_VENDOR_ID_NVIDIA, 0x0051,
307         PCI_ANY_ID, PCI_ANY_ID, }, /* nvidia ck804 */
308 	{ 0, }
309 };
310 
311 MODULE_DEVICE_TABLE(pci, ck804xrom_pci_tbl);
312 
313 #if 0
314 static struct pci_driver ck804xrom_driver = {
315 	.name =		MOD_NAME,
316 	.id_table =	ck804xrom_pci_tbl,
317 	.probe =	ck804xrom_init_one,
318 	.remove =	ck804xrom_remove_one,
319 };
320 #endif
321 
322 static int __init init_ck804xrom(void)
323 {
324 	struct pci_dev *pdev;
325 	struct pci_device_id *id;
326 	int retVal;
327 	pdev = NULL;
328 
329 	for(id = ck804xrom_pci_tbl; id->vendor; id++) {
330 		pdev = pci_get_device(id->vendor, id->device, NULL);
331 		if (pdev)
332 			break;
333 	}
334 	if (pdev) {
335 		retVal = ck804xrom_init_one(pdev, &ck804xrom_pci_tbl[0]);
336 		pci_dev_put(pdev);
337 		return retVal;
338 	}
339 	return -ENXIO;
340 #if 0
341 	return pci_register_driver(&ck804xrom_driver);
342 #endif
343 }
344 
345 static void __exit cleanup_ck804xrom(void)
346 {
347 	ck804xrom_remove_one(ck804xrom_window.pdev);
348 }
349 
350 module_init(init_ck804xrom);
351 module_exit(cleanup_ck804xrom);
352 
353 MODULE_LICENSE("GPL");
354 MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>, Dave Olsen <dolsen@lnxi.com>");
355 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the Nvidia ck804 southbridge");
356 
357