1 /*
2  * Broadcom specific AMBA
3  * ChipCommon serial flash interface
4  *
5  * Licensed under the GNU/GPL. See COPYING for details.
6  */
7 
8 #include <linux/platform_device.h>
9 #include <linux/bcma/bcma.h>
10 
11 #include "bcma_private.h"
12 
13 static struct resource bcma_sflash_resource = {
14 	.name	= "bcma_sflash",
15 	.start	= BCMA_SFLASH,
16 	.end	= 0,
17 	.flags  = IORESOURCE_MEM | IORESOURCE_READONLY,
18 };
19 
20 struct platform_device bcma_sflash_dev = {
21 	.name		= "bcma_sflash",
22 	.resource	= &bcma_sflash_resource,
23 	.num_resources	= 1,
24 };
25 
26 struct bcma_sflash_tbl_e {
27 	char *name;
28 	u32 id;
29 	u32 blocksize;
30 	u16 numblocks;
31 };
32 
33 static struct bcma_sflash_tbl_e bcma_sflash_st_tbl[] = {
34 	{ "", 0x14, 0x10000, 32, },
35 	{ 0 },
36 };
37 
38 static struct bcma_sflash_tbl_e bcma_sflash_sst_tbl[] = {
39 	{ 0 },
40 };
41 
42 static struct bcma_sflash_tbl_e bcma_sflash_at_tbl[] = {
43 	{ 0 },
44 };
45 
46 static void bcma_sflash_cmd(struct bcma_drv_cc *cc, u32 opcode)
47 {
48 	int i;
49 	bcma_cc_write32(cc, BCMA_CC_FLASHCTL,
50 			BCMA_CC_FLASHCTL_START | opcode);
51 	for (i = 0; i < 1000; i++) {
52 		if (!(bcma_cc_read32(cc, BCMA_CC_FLASHCTL) &
53 		      BCMA_CC_FLASHCTL_BUSY))
54 			return;
55 		cpu_relax();
56 	}
57 	bcma_err(cc->core->bus, "SFLASH control command failed (timeout)!\n");
58 }
59 
60 /* Initialize serial flash access */
61 int bcma_sflash_init(struct bcma_drv_cc *cc)
62 {
63 	struct bcma_bus *bus = cc->core->bus;
64 	struct bcma_sflash *sflash = &cc->sflash;
65 	struct bcma_sflash_tbl_e *e;
66 	u32 id, id2;
67 
68 	switch (cc->capabilities & BCMA_CC_CAP_FLASHT) {
69 	case BCMA_CC_FLASHT_STSER:
70 		bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_ST_DP);
71 
72 		bcma_cc_write32(cc, BCMA_CC_FLASHADDR, 0);
73 		bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_ST_RES);
74 		id = bcma_cc_read32(cc, BCMA_CC_FLASHDATA);
75 
76 		bcma_cc_write32(cc, BCMA_CC_FLASHADDR, 1);
77 		bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_ST_RES);
78 		id2 = bcma_cc_read32(cc, BCMA_CC_FLASHDATA);
79 
80 		switch (id) {
81 		case 0xbf:
82 			for (e = bcma_sflash_sst_tbl; e->name; e++) {
83 				if (e->id == id2)
84 					break;
85 			}
86 			break;
87 		default:
88 			for (e = bcma_sflash_st_tbl; e->name; e++) {
89 				if (e->id == id)
90 					break;
91 			}
92 			break;
93 		}
94 		if (!e->name) {
95 			bcma_err(bus, "Unsupported ST serial flash (id: 0x%X, id2: 0x%X)\n", id, id2);
96 			return -ENOTSUPP;
97 		}
98 
99 		break;
100 	case BCMA_CC_FLASHT_ATSER:
101 		bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_AT_STATUS);
102 		id = bcma_cc_read32(cc, BCMA_CC_FLASHDATA) & 0x3c;
103 
104 		for (e = bcma_sflash_at_tbl; e->name; e++) {
105 			if (e->id == id)
106 				break;
107 		}
108 		if (!e->name) {
109 			bcma_err(bus, "Unsupported Atmel serial flash (id: 0x%X)\n", id);
110 			return -ENOTSUPP;
111 		}
112 
113 		break;
114 	default:
115 		bcma_err(bus, "Unsupported flash type\n");
116 		return -ENOTSUPP;
117 	}
118 
119 	sflash->window = BCMA_SFLASH;
120 	sflash->blocksize = e->blocksize;
121 	sflash->numblocks = e->numblocks;
122 	sflash->size = sflash->blocksize * sflash->numblocks;
123 	sflash->present = true;
124 
125 	bcma_info(bus, "Found %s serial flash (size: %dKiB, blocksize: 0x%X, blocks: %d)\n",
126 		  e->name, sflash->size / 1024, sflash->blocksize,
127 		  sflash->numblocks);
128 
129 	/* Prepare platform device, but don't register it yet. It's too early,
130 	 * malloc (required by device_private_init) is not available yet. */
131 	bcma_sflash_dev.resource[0].end = bcma_sflash_dev.resource[0].start +
132 					  sflash->size;
133 	bcma_sflash_dev.dev.platform_data = sflash;
134 
135 	return 0;
136 }
137