1 /*
2  * Sonics Silicon Backplane
3  * ChipCommon serial flash interface
4  *
5  * Licensed under the GNU/GPL. See COPYING for details.
6  */
7 
8 #include <linux/ssb/ssb.h>
9 
10 #include "ssb_private.h"
11 
12 static struct resource ssb_sflash_resource = {
13 	.name	= "ssb_sflash",
14 	.start	= SSB_FLASH2,
15 	.end	= 0,
16 	.flags  = IORESOURCE_MEM | IORESOURCE_READONLY,
17 };
18 
19 struct platform_device ssb_sflash_dev = {
20 	.name		= "ssb_sflash",
21 	.resource	= &ssb_sflash_resource,
22 	.num_resources	= 1,
23 };
24 
25 struct ssb_sflash_tbl_e {
26 	char *name;
27 	u32 id;
28 	u32 blocksize;
29 	u16 numblocks;
30 };
31 
32 static const struct ssb_sflash_tbl_e ssb_sflash_st_tbl[] = {
33 	{ "M25P20", 0x11, 0x10000, 4, },
34 	{ "M25P40", 0x12, 0x10000, 8, },
35 
36 	{ "M25P16", 0x14, 0x10000, 32, },
37 	{ "M25P32", 0x15, 0x10000, 64, },
38 	{ "M25P64", 0x16, 0x10000, 128, },
39 	{ "M25FL128", 0x17, 0x10000, 256, },
40 	{ NULL },
41 };
42 
43 static const struct ssb_sflash_tbl_e ssb_sflash_sst_tbl[] = {
44 	{ "SST25WF512", 1, 0x1000, 16, },
45 	{ "SST25VF512", 0x48, 0x1000, 16, },
46 	{ "SST25WF010", 2, 0x1000, 32, },
47 	{ "SST25VF010", 0x49, 0x1000, 32, },
48 	{ "SST25WF020", 3, 0x1000, 64, },
49 	{ "SST25VF020", 0x43, 0x1000, 64, },
50 	{ "SST25WF040", 4, 0x1000, 128, },
51 	{ "SST25VF040", 0x44, 0x1000, 128, },
52 	{ "SST25VF040B", 0x8d, 0x1000, 128, },
53 	{ "SST25WF080", 5, 0x1000, 256, },
54 	{ "SST25VF080B", 0x8e, 0x1000, 256, },
55 	{ "SST25VF016", 0x41, 0x1000, 512, },
56 	{ "SST25VF032", 0x4a, 0x1000, 1024, },
57 	{ "SST25VF064", 0x4b, 0x1000, 2048, },
58 	{ NULL },
59 };
60 
61 static const struct ssb_sflash_tbl_e ssb_sflash_at_tbl[] = {
62 	{ "AT45DB011", 0xc, 256, 512, },
63 	{ "AT45DB021", 0x14, 256, 1024, },
64 	{ "AT45DB041", 0x1c, 256, 2048, },
65 	{ "AT45DB081", 0x24, 256, 4096, },
66 	{ "AT45DB161", 0x2c, 512, 4096, },
67 	{ "AT45DB321", 0x34, 512, 8192, },
68 	{ "AT45DB642", 0x3c, 1024, 8192, },
69 	{ NULL },
70 };
71 
72 static void ssb_sflash_cmd(struct ssb_chipcommon *cc, u32 opcode)
73 {
74 	int i;
75 	chipco_write32(cc, SSB_CHIPCO_FLASHCTL,
76 		       SSB_CHIPCO_FLASHCTL_START | opcode);
77 	for (i = 0; i < 1000; i++) {
78 		if (!(chipco_read32(cc, SSB_CHIPCO_FLASHCTL) &
79 		      SSB_CHIPCO_FLASHCTL_BUSY))
80 			return;
81 		cpu_relax();
82 	}
83 	pr_err("SFLASH control command failed (timeout)!\n");
84 }
85 
86 /* Initialize serial flash access */
87 int ssb_sflash_init(struct ssb_chipcommon *cc)
88 {
89 	struct ssb_sflash *sflash = &cc->dev->bus->mipscore.sflash;
90 	const struct ssb_sflash_tbl_e *e;
91 	u32 id, id2;
92 
93 	switch (cc->capabilities & SSB_CHIPCO_CAP_FLASHT) {
94 	case SSB_CHIPCO_FLASHT_STSER:
95 		ssb_sflash_cmd(cc, SSB_CHIPCO_FLASHCTL_ST_DP);
96 
97 		chipco_write32(cc, SSB_CHIPCO_FLASHADDR, 0);
98 		ssb_sflash_cmd(cc, SSB_CHIPCO_FLASHCTL_ST_RES);
99 		id = chipco_read32(cc, SSB_CHIPCO_FLASHDATA);
100 
101 		chipco_write32(cc, SSB_CHIPCO_FLASHADDR, 1);
102 		ssb_sflash_cmd(cc, SSB_CHIPCO_FLASHCTL_ST_RES);
103 		id2 = chipco_read32(cc, SSB_CHIPCO_FLASHDATA);
104 
105 		switch (id) {
106 		case 0xbf:
107 			for (e = ssb_sflash_sst_tbl; e->name; e++) {
108 				if (e->id == id2)
109 					break;
110 			}
111 			break;
112 		case 0x13:
113 			return -ENOTSUPP;
114 		default:
115 			for (e = ssb_sflash_st_tbl; e->name; e++) {
116 				if (e->id == id)
117 					break;
118 			}
119 			break;
120 		}
121 		if (!e->name) {
122 			pr_err("Unsupported ST serial flash (id: 0x%X, id2: 0x%X)\n",
123 			       id, id2);
124 			return -ENOTSUPP;
125 		}
126 
127 		break;
128 	case SSB_CHIPCO_FLASHT_ATSER:
129 		ssb_sflash_cmd(cc, SSB_CHIPCO_FLASHCTL_AT_STATUS);
130 		id = chipco_read32(cc, SSB_CHIPCO_FLASHDATA) & 0x3c;
131 
132 		for (e = ssb_sflash_at_tbl; e->name; e++) {
133 			if (e->id == id)
134 				break;
135 		}
136 		if (!e->name) {
137 			pr_err("Unsupported Atmel serial flash (id: 0x%X)\n",
138 			       id);
139 			return -ENOTSUPP;
140 		}
141 
142 		break;
143 	default:
144 		pr_err("Unsupported flash type\n");
145 		return -ENOTSUPP;
146 	}
147 
148 	sflash->window = SSB_FLASH2;
149 	sflash->blocksize = e->blocksize;
150 	sflash->numblocks = e->numblocks;
151 	sflash->size = sflash->blocksize * sflash->numblocks;
152 	sflash->present = true;
153 
154 	pr_info("Found %s serial flash (size: %dKiB, blocksize: 0x%X, blocks: %d)\n",
155 		e->name, sflash->size / 1024, e->blocksize, e->numblocks);
156 
157 	/* Prepare platform device, but don't register it yet. It's too early,
158 	 * malloc (required by device_private_init) is not available yet. */
159 	ssb_sflash_dev.resource[0].end = ssb_sflash_dev.resource[0].start +
160 					 sflash->size;
161 	ssb_sflash_dev.dev.platform_data = sflash;
162 
163 	return 0;
164 }
165