xref: /openbmc/linux/drivers/mtd/maps/ck804xrom.c (revision 82ced6fd)
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/kernel.h>
13 #include <linux/init.h>
14 #include <asm/io.h>
15 #include <linux/mtd/mtd.h>
16 #include <linux/mtd/map.h>
17 #include <linux/mtd/cfi.h>
18 #include <linux/mtd/flashchip.h>
19 #include <linux/pci.h>
20 #include <linux/pci_ids.h>
21 #include <linux/list.h>
22 
23 
24 #define MOD_NAME KBUILD_BASENAME
25 
26 #define ADDRESS_NAME_LEN 18
27 
28 #define ROM_PROBE_STEP_SIZE (64*1024)
29 
30 #define DEV_CK804 1
31 #define DEV_MCP55 2
32 
33 struct ck804xrom_window {
34 	void __iomem *virt;
35 	unsigned long phys;
36 	unsigned long size;
37 	struct list_head maps;
38 	struct resource rsrc;
39 	struct pci_dev *pdev;
40 };
41 
42 struct ck804xrom_map_info {
43 	struct list_head list;
44 	struct map_info map;
45 	struct mtd_info *mtd;
46 	struct resource rsrc;
47 	char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
48 };
49 
50 /*
51  * The following applies to ck804 only:
52  * The 2 bits controlling the window size are often set to allow reading
53  * the BIOS, but too small to allow writing, since the lock registers are
54  * 4MiB lower in the address space than the data.
55  *
56  * This is intended to prevent flashing the bios, perhaps accidentally.
57  *
58  * This parameter allows the normal driver to override the BIOS settings.
59  *
60  * The bits are 6 and 7.  If both bits are set, it is a 5MiB window.
61  * If only the 7 Bit is set, it is a 4MiB window.  Otherwise, a
62  * 64KiB window.
63  *
64  * The following applies to mcp55 only:
65  * The 15 bits controlling the window size are distributed as follows:
66  * byte @0x88: bit 0..7
67  * byte @0x8c: bit 8..15
68  * word @0x90: bit 16..30
69  * If all bits are enabled, we have a 16? MiB window
70  * Please set win_size_bits to 0x7fffffff if you actually want to do something
71  */
72 static uint win_size_bits = 0;
73 module_param(win_size_bits, uint, 0);
74 MODULE_PARM_DESC(win_size_bits, "ROM window size bits override, normally set by BIOS.");
75 
76 static struct ck804xrom_window ck804xrom_window = {
77 	.maps = LIST_HEAD_INIT(ck804xrom_window.maps),
78 };
79 
80 static void ck804xrom_cleanup(struct ck804xrom_window *window)
81 {
82 	struct ck804xrom_map_info *map, *scratch;
83 	u8 byte;
84 
85 	if (window->pdev) {
86 		/* Disable writes through the rom window */
87 		pci_read_config_byte(window->pdev, 0x6d, &byte);
88 		pci_write_config_byte(window->pdev, 0x6d, byte & ~1);
89 	}
90 
91 	/* Free all of the mtd devices */
92 	list_for_each_entry_safe(map, scratch, &window->maps, list) {
93 		if (map->rsrc.parent)
94 			release_resource(&map->rsrc);
95 
96 		del_mtd_device(map->mtd);
97 		map_destroy(map->mtd);
98 		list_del(&map->list);
99 		kfree(map);
100 	}
101 	if (window->rsrc.parent)
102 		release_resource(&window->rsrc);
103 
104 	if (window->virt) {
105 		iounmap(window->virt);
106 		window->virt = NULL;
107 		window->phys = 0;
108 		window->size = 0;
109 	}
110 	pci_dev_put(window->pdev);
111 }
112 
113 
114 static int __devinit ck804xrom_init_one (struct pci_dev *pdev,
115 					 const struct pci_device_id *ent)
116 {
117 	static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
118 	u8 byte;
119 	u16 word;
120 	struct ck804xrom_window *window = &ck804xrom_window;
121 	struct ck804xrom_map_info *map = NULL;
122 	unsigned long map_top;
123 
124 	/* Remember the pci dev I find the window in */
125 	window->pdev = pci_dev_get(pdev);
126 
127 	switch (ent->driver_data) {
128 	case DEV_CK804:
129 		/* Enable the selected rom window.  This is often incorrectly
130 		 * set up by the BIOS, and the 4MiB offset for the lock registers
131 		 * requires the full 5MiB of window space.
132 		 *
133 		 * This 'write, then read' approach leaves the bits for
134 		 * other uses of the hardware info.
135 		 */
136 		pci_read_config_byte(pdev, 0x88, &byte);
137 		pci_write_config_byte(pdev, 0x88, byte | win_size_bits );
138 
139 		/* Assume the rom window is properly setup, and find it's size */
140 		pci_read_config_byte(pdev, 0x88, &byte);
141 
142 		if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6)))
143 			window->phys = 0xffb00000; /* 5MiB */
144 		else if ((byte & (1<<7)) == (1<<7))
145 			window->phys = 0xffc00000; /* 4MiB */
146 		else
147 			window->phys = 0xffff0000; /* 64KiB */
148 		break;
149 
150 	case DEV_MCP55:
151 		pci_read_config_byte(pdev, 0x88, &byte);
152 		pci_write_config_byte(pdev, 0x88, byte | (win_size_bits & 0xff));
153 
154 		pci_read_config_byte(pdev, 0x8c, &byte);
155 		pci_write_config_byte(pdev, 0x8c, byte | ((win_size_bits & 0xff00) >> 8));
156 
157 		pci_read_config_word(pdev, 0x90, &word);
158 		pci_write_config_word(pdev, 0x90, word | ((win_size_bits & 0x7fff0000) >> 16));
159 
160 		window->phys = 0xff000000; /* 16MiB, hardcoded for now */
161 		break;
162 	}
163 
164 	window->size = 0xffffffffUL - window->phys + 1UL;
165 
166 	/*
167 	 * Try to reserve the window mem region.  If this fails then
168 	 * it is likely due to a fragment of the window being
169 	 * "reserved" by the BIOS.  In the case that the
170 	 * request_mem_region() fails then once the rom size is
171 	 * discovered we will try to reserve the unreserved fragment.
172 	 */
173 	window->rsrc.name = MOD_NAME;
174 	window->rsrc.start = window->phys;
175 	window->rsrc.end   = window->phys + window->size - 1;
176 	window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
177 	if (request_resource(&iomem_resource, &window->rsrc)) {
178 		window->rsrc.parent = NULL;
179 		printk(KERN_ERR MOD_NAME
180 			" %s(): Unable to register resource"
181 			" 0x%.016llx-0x%.016llx - kernel bug?\n",
182 			__func__,
183 			(unsigned long long)window->rsrc.start,
184 			(unsigned long long)window->rsrc.end);
185 	}
186 
187 
188 	/* Enable writes through the rom window */
189 	pci_read_config_byte(pdev, 0x6d, &byte);
190 	pci_write_config_byte(pdev, 0x6d, byte | 1);
191 
192 	/* FIXME handle registers 0x80 - 0x8C the bios region locks */
193 
194 	/* For write accesses caches are useless */
195 	window->virt = ioremap_nocache(window->phys, window->size);
196 	if (!window->virt) {
197 		printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
198 			window->phys, window->size);
199 		goto out;
200 	}
201 
202 	/* Get the first address to look for a rom chip at */
203 	map_top = window->phys;
204 #if 1
205 	/* The probe sequence run over the firmware hub lock
206 	 * registers sets them to 0x7 (no access).
207 	 * Probe at most the last 4MiB of the address space.
208 	 */
209 	if (map_top < 0xffc00000)
210 		map_top = 0xffc00000;
211 #endif
212 	/* Loop  through and look for rom chips.  Since we don't know the
213 	 * starting address for each chip, probe every ROM_PROBE_STEP_SIZE
214 	 * bytes from the starting address of the window.
215 	 */
216 	while((map_top - 1) < 0xffffffffUL) {
217 		struct cfi_private *cfi;
218 		unsigned long offset;
219 		int i;
220 
221 		if (!map)
222 			map = kmalloc(sizeof(*map), GFP_KERNEL);
223 
224 		if (!map) {
225 			printk(KERN_ERR MOD_NAME ": kmalloc failed");
226 			goto out;
227 		}
228 		memset(map, 0, sizeof(*map));
229 		INIT_LIST_HEAD(&map->list);
230 		map->map.name = map->map_name;
231 		map->map.phys = map_top;
232 		offset = map_top - window->phys;
233 		map->map.virt = (void __iomem *)
234 			(((unsigned long)(window->virt)) + offset);
235 		map->map.size = 0xffffffffUL - map_top + 1UL;
236 		/* Set the name of the map to the address I am trying */
237 		sprintf(map->map_name, "%s @%08Lx",
238 			MOD_NAME, (unsigned long long)map->map.phys);
239 
240 		/* There is no generic VPP support */
241 		for(map->map.bankwidth = 32; map->map.bankwidth;
242 			map->map.bankwidth >>= 1)
243 		{
244 			char **probe_type;
245 			/* Skip bankwidths that are not supported */
246 			if (!map_bankwidth_supported(map->map.bankwidth))
247 				continue;
248 
249 			/* Setup the map methods */
250 			simple_map_init(&map->map);
251 
252 			/* Try all of the probe methods */
253 			probe_type = rom_probe_types;
254 			for(; *probe_type; probe_type++) {
255 				map->mtd = do_map_probe(*probe_type, &map->map);
256 				if (map->mtd)
257 					goto found;
258 			}
259 		}
260 		map_top += ROM_PROBE_STEP_SIZE;
261 		continue;
262 	found:
263 		/* Trim the size if we are larger than the map */
264 		if (map->mtd->size > map->map.size) {
265 			printk(KERN_WARNING MOD_NAME
266 				" rom(%llu) larger than window(%lu). fixing...\n",
267 				(unsigned long long)map->mtd->size, map->map.size);
268 			map->mtd->size = map->map.size;
269 		}
270 		if (window->rsrc.parent) {
271 			/*
272 			 * Registering the MTD device in iomem may not be possible
273 			 * if there is a BIOS "reserved" and BUSY range.  If this
274 			 * fails then continue anyway.
275 			 */
276 			map->rsrc.name  = map->map_name;
277 			map->rsrc.start = map->map.phys;
278 			map->rsrc.end   = map->map.phys + map->mtd->size - 1;
279 			map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
280 			if (request_resource(&window->rsrc, &map->rsrc)) {
281 				printk(KERN_ERR MOD_NAME
282 					": cannot reserve MTD resource\n");
283 				map->rsrc.parent = NULL;
284 			}
285 		}
286 
287 		/* Make the whole region visible in the map */
288 		map->map.virt = window->virt;
289 		map->map.phys = window->phys;
290 		cfi = map->map.fldrv_priv;
291 		for(i = 0; i < cfi->numchips; i++)
292 			cfi->chips[i].start += offset;
293 
294 		/* Now that the mtd devices is complete claim and export it */
295 		map->mtd->owner = THIS_MODULE;
296 		if (add_mtd_device(map->mtd)) {
297 			map_destroy(map->mtd);
298 			map->mtd = NULL;
299 			goto out;
300 		}
301 
302 
303 		/* Calculate the new value of map_top */
304 		map_top += map->mtd->size;
305 
306 		/* File away the map structure */
307 		list_add(&map->list, &window->maps);
308 		map = NULL;
309 	}
310 
311  out:
312 	/* Free any left over map structures */
313 	if (map)
314 		kfree(map);
315 
316 	/* See if I have any map structures */
317 	if (list_empty(&window->maps)) {
318 		ck804xrom_cleanup(window);
319 		return -ENODEV;
320 	}
321 	return 0;
322 }
323 
324 
325 static void __devexit ck804xrom_remove_one (struct pci_dev *pdev)
326 {
327 	struct ck804xrom_window *window = &ck804xrom_window;
328 
329 	ck804xrom_cleanup(window);
330 }
331 
332 static struct pci_device_id ck804xrom_pci_tbl[] = {
333 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0051), .driver_data = DEV_CK804 },
334 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0360), .driver_data = DEV_MCP55 },
335 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0361), .driver_data = DEV_MCP55 },
336 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0362), .driver_data = DEV_MCP55 },
337 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0363), .driver_data = DEV_MCP55 },
338 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0364), .driver_data = DEV_MCP55 },
339 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0365), .driver_data = DEV_MCP55 },
340 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0366), .driver_data = DEV_MCP55 },
341 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0367), .driver_data = DEV_MCP55 },
342 	{ 0, }
343 };
344 
345 #if 0
346 MODULE_DEVICE_TABLE(pci, ck804xrom_pci_tbl);
347 
348 static struct pci_driver ck804xrom_driver = {
349 	.name =		MOD_NAME,
350 	.id_table =	ck804xrom_pci_tbl,
351 	.probe =	ck804xrom_init_one,
352 	.remove =	ck804xrom_remove_one,
353 };
354 #endif
355 
356 static int __init init_ck804xrom(void)
357 {
358 	struct pci_dev *pdev;
359 	struct pci_device_id *id;
360 	int retVal;
361 	pdev = NULL;
362 
363 	for(id = ck804xrom_pci_tbl; id->vendor; id++) {
364 		pdev = pci_get_device(id->vendor, id->device, NULL);
365 		if (pdev)
366 			break;
367 	}
368 	if (pdev) {
369 		retVal = ck804xrom_init_one(pdev, id);
370 		pci_dev_put(pdev);
371 		return retVal;
372 	}
373 	return -ENXIO;
374 #if 0
375 	return pci_register_driver(&ck804xrom_driver);
376 #endif
377 }
378 
379 static void __exit cleanup_ck804xrom(void)
380 {
381 	ck804xrom_remove_one(ck804xrom_window.pdev);
382 }
383 
384 module_init(init_ck804xrom);
385 module_exit(cleanup_ck804xrom);
386 
387 MODULE_LICENSE("GPL");
388 MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>, Dave Olsen <dolsen@lnxi.com>");
389 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the Nvidia ck804 southbridge");
390 
391