xref: /openbmc/linux/drivers/mtd/maps/ck804xrom.c (revision a2818ee4)
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 <linux/slab.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 #define DEV_CK804 1
32 #define DEV_MCP55 2
33 
34 struct ck804xrom_window {
35 	void __iomem *virt;
36 	unsigned long phys;
37 	unsigned long size;
38 	struct list_head maps;
39 	struct resource rsrc;
40 	struct pci_dev *pdev;
41 };
42 
43 struct ck804xrom_map_info {
44 	struct list_head list;
45 	struct map_info map;
46 	struct mtd_info *mtd;
47 	struct resource rsrc;
48 	char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
49 };
50 
51 /*
52  * The following applies to ck804 only:
53  * The 2 bits controlling the window size are often set to allow reading
54  * the BIOS, but too small to allow writing, since the lock registers are
55  * 4MiB lower in the address space than the data.
56  *
57  * This is intended to prevent flashing the bios, perhaps accidentally.
58  *
59  * This parameter allows the normal driver to override the BIOS settings.
60  *
61  * The bits are 6 and 7.  If both bits are set, it is a 5MiB window.
62  * If only the 7 Bit is set, it is a 4MiB window.  Otherwise, a
63  * 64KiB window.
64  *
65  * The following applies to mcp55 only:
66  * The 15 bits controlling the window size are distributed as follows:
67  * byte @0x88: bit 0..7
68  * byte @0x8c: bit 8..15
69  * word @0x90: bit 16..30
70  * If all bits are enabled, we have a 16? MiB window
71  * Please set win_size_bits to 0x7fffffff if you actually want to do something
72  */
73 static uint win_size_bits = 0;
74 module_param(win_size_bits, uint, 0);
75 MODULE_PARM_DESC(win_size_bits, "ROM window size bits override, normally set by BIOS.");
76 
77 static struct ck804xrom_window ck804xrom_window = {
78 	.maps = LIST_HEAD_INIT(ck804xrom_window.maps),
79 };
80 
81 static void ck804xrom_cleanup(struct ck804xrom_window *window)
82 {
83 	struct ck804xrom_map_info *map, *scratch;
84 	u8 byte;
85 
86 	if (window->pdev) {
87 		/* Disable writes through the rom window */
88 		pci_read_config_byte(window->pdev, 0x6d, &byte);
89 		pci_write_config_byte(window->pdev, 0x6d, byte & ~1);
90 	}
91 
92 	/* Free all of the mtd devices */
93 	list_for_each_entry_safe(map, scratch, &window->maps, list) {
94 		if (map->rsrc.parent)
95 			release_resource(&map->rsrc);
96 
97 		mtd_device_unregister(map->mtd);
98 		map_destroy(map->mtd);
99 		list_del(&map->list);
100 		kfree(map);
101 	}
102 	if (window->rsrc.parent)
103 		release_resource(&window->rsrc);
104 
105 	if (window->virt) {
106 		iounmap(window->virt);
107 		window->virt = NULL;
108 		window->phys = 0;
109 		window->size = 0;
110 	}
111 	pci_dev_put(window->pdev);
112 }
113 
114 
115 static int __init ck804xrom_init_one(struct pci_dev *pdev,
116 				     const struct pci_device_id *ent)
117 {
118 	static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
119 	u8 byte;
120 	u16 word;
121 	struct ck804xrom_window *window = &ck804xrom_window;
122 	struct ck804xrom_map_info *map = NULL;
123 	unsigned long map_top;
124 
125 	/* Remember the pci dev I find the window in */
126 	window->pdev = pci_dev_get(pdev);
127 
128 	switch (ent->driver_data) {
129 	case DEV_CK804:
130 		/* Enable the selected rom window.  This is often incorrectly
131 		 * set up by the BIOS, and the 4MiB offset for the lock registers
132 		 * requires the full 5MiB of window space.
133 		 *
134 		 * This 'write, then read' approach leaves the bits for
135 		 * other uses of the hardware info.
136 		 */
137 		pci_read_config_byte(pdev, 0x88, &byte);
138 		pci_write_config_byte(pdev, 0x88, byte | win_size_bits );
139 
140 		/* Assume the rom window is properly setup, and find it's size */
141 		pci_read_config_byte(pdev, 0x88, &byte);
142 
143 		if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6)))
144 			window->phys = 0xffb00000; /* 5MiB */
145 		else if ((byte & (1<<7)) == (1<<7))
146 			window->phys = 0xffc00000; /* 4MiB */
147 		else
148 			window->phys = 0xffff0000; /* 64KiB */
149 		break;
150 
151 	case DEV_MCP55:
152 		pci_read_config_byte(pdev, 0x88, &byte);
153 		pci_write_config_byte(pdev, 0x88, byte | (win_size_bits & 0xff));
154 
155 		pci_read_config_byte(pdev, 0x8c, &byte);
156 		pci_write_config_byte(pdev, 0x8c, byte | ((win_size_bits & 0xff00) >> 8));
157 
158 		pci_read_config_word(pdev, 0x90, &word);
159 		pci_write_config_word(pdev, 0x90, word | ((win_size_bits & 0x7fff0000) >> 16));
160 
161 		window->phys = 0xff000000; /* 16MiB, hardcoded for now */
162 		break;
163 	}
164 
165 	window->size = 0xffffffffUL - window->phys + 1UL;
166 
167 	/*
168 	 * Try to reserve the window mem region.  If this fails then
169 	 * it is likely due to a fragment of the window being
170 	 * "reserved" by the BIOS.  In the case that the
171 	 * request_mem_region() fails then once the rom size is
172 	 * discovered we will try to reserve the unreserved fragment.
173 	 */
174 	window->rsrc.name = MOD_NAME;
175 	window->rsrc.start = window->phys;
176 	window->rsrc.end   = window->phys + window->size - 1;
177 	window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
178 	if (request_resource(&iomem_resource, &window->rsrc)) {
179 		window->rsrc.parent = NULL;
180 		printk(KERN_ERR MOD_NAME
181 		       " %s(): Unable to register resource %pR - kernel bug?\n",
182 			__func__, &window->rsrc);
183 	}
184 
185 
186 	/* Enable writes through the rom window */
187 	pci_read_config_byte(pdev, 0x6d, &byte);
188 	pci_write_config_byte(pdev, 0x6d, byte | 1);
189 
190 	/* FIXME handle registers 0x80 - 0x8C the bios region locks */
191 
192 	/* For write accesses caches are useless */
193 	window->virt = ioremap_nocache(window->phys, window->size);
194 	if (!window->virt) {
195 		printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
196 			window->phys, window->size);
197 		goto out;
198 	}
199 
200 	/* Get the first address to look for a rom chip at */
201 	map_top = window->phys;
202 #if 1
203 	/* The probe sequence run over the firmware hub lock
204 	 * registers sets them to 0x7 (no access).
205 	 * Probe at most the last 4MiB of the address space.
206 	 */
207 	if (map_top < 0xffc00000)
208 		map_top = 0xffc00000;
209 #endif
210 	/* Loop  through and look for rom chips.  Since we don't know the
211 	 * starting address for each chip, probe every ROM_PROBE_STEP_SIZE
212 	 * bytes from the starting address of the window.
213 	 */
214 	while((map_top - 1) < 0xffffffffUL) {
215 		struct cfi_private *cfi;
216 		unsigned long offset;
217 		int i;
218 
219 		if (!map)
220 			map = kmalloc(sizeof(*map), GFP_KERNEL);
221 
222 		if (!map) {
223 			printk(KERN_ERR MOD_NAME ": kmalloc failed");
224 			goto out;
225 		}
226 		memset(map, 0, sizeof(*map));
227 		INIT_LIST_HEAD(&map->list);
228 		map->map.name = map->map_name;
229 		map->map.phys = map_top;
230 		offset = map_top - window->phys;
231 		map->map.virt = (void __iomem *)
232 			(((unsigned long)(window->virt)) + offset);
233 		map->map.size = 0xffffffffUL - map_top + 1UL;
234 		/* Set the name of the map to the address I am trying */
235 		sprintf(map->map_name, "%s @%08Lx",
236 			MOD_NAME, (unsigned long long)map->map.phys);
237 
238 		/* There is no generic VPP support */
239 		for(map->map.bankwidth = 32; map->map.bankwidth;
240 			map->map.bankwidth >>= 1)
241 		{
242 			char **probe_type;
243 			/* Skip bankwidths that are not supported */
244 			if (!map_bankwidth_supported(map->map.bankwidth))
245 				continue;
246 
247 			/* Setup the map methods */
248 			simple_map_init(&map->map);
249 
250 			/* Try all of the probe methods */
251 			probe_type = rom_probe_types;
252 			for(; *probe_type; probe_type++) {
253 				map->mtd = do_map_probe(*probe_type, &map->map);
254 				if (map->mtd)
255 					goto found;
256 			}
257 		}
258 		map_top += ROM_PROBE_STEP_SIZE;
259 		continue;
260 	found:
261 		/* Trim the size if we are larger than the map */
262 		if (map->mtd->size > map->map.size) {
263 			printk(KERN_WARNING MOD_NAME
264 				" rom(%llu) larger than window(%lu). fixing...\n",
265 				(unsigned long long)map->mtd->size, map->map.size);
266 			map->mtd->size = map->map.size;
267 		}
268 		if (window->rsrc.parent) {
269 			/*
270 			 * Registering the MTD device in iomem may not be possible
271 			 * if there is a BIOS "reserved" and BUSY range.  If this
272 			 * fails then continue anyway.
273 			 */
274 			map->rsrc.name  = map->map_name;
275 			map->rsrc.start = map->map.phys;
276 			map->rsrc.end   = map->map.phys + map->mtd->size - 1;
277 			map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
278 			if (request_resource(&window->rsrc, &map->rsrc)) {
279 				printk(KERN_ERR MOD_NAME
280 					": cannot reserve MTD resource\n");
281 				map->rsrc.parent = NULL;
282 			}
283 		}
284 
285 		/* Make the whole region visible in the map */
286 		map->map.virt = window->virt;
287 		map->map.phys = window->phys;
288 		cfi = map->map.fldrv_priv;
289 		for(i = 0; i < cfi->numchips; i++)
290 			cfi->chips[i].start += offset;
291 
292 		/* Now that the mtd devices is complete claim and export it */
293 		map->mtd->owner = THIS_MODULE;
294 		if (mtd_device_register(map->mtd, NULL, 0)) {
295 			map_destroy(map->mtd);
296 			map->mtd = NULL;
297 			goto out;
298 		}
299 
300 
301 		/* Calculate the new value of map_top */
302 		map_top += map->mtd->size;
303 
304 		/* File away the map structure */
305 		list_add(&map->list, &window->maps);
306 		map = NULL;
307 	}
308 
309  out:
310 	/* Free any left over map structures */
311 	kfree(map);
312 
313 	/* See if I have any map structures */
314 	if (list_empty(&window->maps)) {
315 		ck804xrom_cleanup(window);
316 		return -ENODEV;
317 	}
318 	return 0;
319 }
320 
321 
322 static void ck804xrom_remove_one(struct pci_dev *pdev)
323 {
324 	struct ck804xrom_window *window = &ck804xrom_window;
325 
326 	ck804xrom_cleanup(window);
327 }
328 
329 static const struct pci_device_id ck804xrom_pci_tbl[] = {
330 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0051), .driver_data = DEV_CK804 },
331 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0360), .driver_data = DEV_MCP55 },
332 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0361), .driver_data = DEV_MCP55 },
333 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0362), .driver_data = DEV_MCP55 },
334 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0363), .driver_data = DEV_MCP55 },
335 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0364), .driver_data = DEV_MCP55 },
336 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0365), .driver_data = DEV_MCP55 },
337 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0366), .driver_data = DEV_MCP55 },
338 	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, 0x0367), .driver_data = DEV_MCP55 },
339 	{ 0, }
340 };
341 
342 #if 0
343 MODULE_DEVICE_TABLE(pci, ck804xrom_pci_tbl);
344 
345 static struct pci_driver ck804xrom_driver = {
346 	.name =		MOD_NAME,
347 	.id_table =	ck804xrom_pci_tbl,
348 	.probe =	ck804xrom_init_one,
349 	.remove =	ck804xrom_remove_one,
350 };
351 #endif
352 
353 static int __init init_ck804xrom(void)
354 {
355 	struct pci_dev *pdev;
356 	const struct pci_device_id *id;
357 	int retVal;
358 	pdev = NULL;
359 
360 	for(id = ck804xrom_pci_tbl; id->vendor; id++) {
361 		pdev = pci_get_device(id->vendor, id->device, NULL);
362 		if (pdev)
363 			break;
364 	}
365 	if (pdev) {
366 		retVal = ck804xrom_init_one(pdev, id);
367 		pci_dev_put(pdev);
368 		return retVal;
369 	}
370 	return -ENXIO;
371 #if 0
372 	return pci_register_driver(&ck804xrom_driver);
373 #endif
374 }
375 
376 static void __exit cleanup_ck804xrom(void)
377 {
378 	ck804xrom_remove_one(ck804xrom_window.pdev);
379 }
380 
381 module_init(init_ck804xrom);
382 module_exit(cleanup_ck804xrom);
383 
384 MODULE_LICENSE("GPL");
385 MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>, Dave Olsen <dolsen@lnxi.com>");
386 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the Nvidia ck804 southbridge");
387 
388