xref: /linux/drivers/mtd/lpddr/qinfo_probe.c (revision f3539c12d8196ce0a1993364d30b3a18908470d1)
1 /*
2  * Probing flash chips with QINFO records.
3  * (C) 2008 Korolev Alexey <akorolev@infradead.org>
4  * (C) 2008 Vasiliy Leonenko <vasiliy.leonenko@gmail.com>
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version 2
9  * of the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19  * 02110-1301, USA.
20  */
21 #include <linux/module.h>
22 #include <linux/types.h>
23 #include <linux/kernel.h>
24 #include <linux/init.h>
25 #include <linux/errno.h>
26 #include <linux/slab.h>
27 #include <linux/interrupt.h>
28 
29 #include <linux/mtd/xip.h>
30 #include <linux/mtd/map.h>
31 #include <linux/mtd/pfow.h>
32 #include <linux/mtd/qinfo.h>
33 
34 static int lpddr_chip_setup(struct map_info *map, struct lpddr_private *lpddr);
35 struct mtd_info *lpddr_probe(struct map_info *map);
36 static struct lpddr_private *lpddr_probe_chip(struct map_info *map);
37 static int lpddr_pfow_present(struct map_info *map,
38 			struct lpddr_private *lpddr);
39 
40 static struct qinfo_query_info qinfo_array[] = {
41 	/* General device info */
42 	{0, 0, "DevSizeShift", "Device size 2^n bytes"},
43 	{0, 3, "BufSizeShift", "Program buffer size 2^n bytes"},
44 	/* Erase block information */
45 	{1, 1, "TotalBlocksNum", "Total number of blocks"},
46 	{1, 2, "UniformBlockSizeShift", "Uniform block size 2^n bytes"},
47 	/* Partition information */
48 	{2, 1, "HWPartsNum", "Number of hardware partitions"},
49 	/* Optional features */
50 	{5, 1, "SuspEraseSupp", "Suspend erase supported"},
51 	/* Operation typical time */
52 	{10, 0, "SingleWordProgTime", "Single word program 2^n u-sec"},
53 	{10, 1, "ProgBufferTime", "Program buffer write 2^n u-sec"},
54 	{10, 2, "BlockEraseTime", "Block erase 2^n m-sec"},
55 	{10, 3, "FullChipEraseTime", "Full chip erase 2^n m-sec"},
56 };
57 
58 static long lpddr_get_qinforec_pos(struct map_info *map, char *id_str)
59 {
60 	int qinfo_lines = ARRAY_SIZE(qinfo_array);
61 	int i;
62 	int bankwidth = map_bankwidth(map) * 8;
63 	int major, minor;
64 
65 	for (i = 0; i < qinfo_lines; i++) {
66 		if (strcmp(id_str, qinfo_array[i].id_str) == 0) {
67 			major = qinfo_array[i].major & ((1 << bankwidth) - 1);
68 			minor = qinfo_array[i].minor & ((1 << bankwidth) - 1);
69 			return minor | (major << bankwidth);
70 		}
71 	}
72 	printk(KERN_ERR"%s qinfo id string is wrong! \n", map->name);
73 	BUG();
74 	return -1;
75 }
76 
77 static uint16_t lpddr_info_query(struct map_info *map, char *id_str)
78 {
79 	unsigned int dsr, val;
80 	int bits_per_chip = map_bankwidth(map) * 8;
81 	unsigned long adr = lpddr_get_qinforec_pos(map, id_str);
82 	int attempts = 20;
83 
84 	/* Write a request for the PFOW record */
85 	map_write(map, CMD(LPDDR_INFO_QUERY),
86 			map->pfow_base + PFOW_COMMAND_CODE);
87 	map_write(map, CMD(adr & ((1 << bits_per_chip) - 1)),
88 			map->pfow_base + PFOW_COMMAND_ADDRESS_L);
89 	map_write(map, CMD(adr >> bits_per_chip),
90 			map->pfow_base + PFOW_COMMAND_ADDRESS_H);
91 	map_write(map, CMD(LPDDR_START_EXECUTION),
92 			map->pfow_base + PFOW_COMMAND_EXECUTE);
93 
94 	while ((attempts--) > 0) {
95 		dsr = CMDVAL(map_read(map, map->pfow_base + PFOW_DSR));
96 		if (dsr & DSR_READY_STATUS)
97 			break;
98 		udelay(10);
99 	}
100 
101 	val = CMDVAL(map_read(map, map->pfow_base + PFOW_COMMAND_DATA));
102 	return val;
103 }
104 
105 static int lpddr_pfow_present(struct map_info *map, struct lpddr_private *lpddr)
106 {
107 	map_word pfow_val[4];
108 
109 	/* Check identification string */
110 	pfow_val[0] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_P);
111 	pfow_val[1] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_F);
112 	pfow_val[2] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_O);
113 	pfow_val[3] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_W);
114 
115 	if (!map_word_equal(map, CMD('P'), pfow_val[0]))
116 		goto out;
117 
118 	if (!map_word_equal(map, CMD('F'), pfow_val[1]))
119 		goto out;
120 
121 	if (!map_word_equal(map, CMD('O'), pfow_val[2]))
122 		goto out;
123 
124 	if (!map_word_equal(map, CMD('W'), pfow_val[3]))
125 		goto out;
126 
127 	return 1;	/* "PFOW" is found */
128 out:
129 	printk(KERN_WARNING"%s: PFOW string at 0x%lx is not found \n",
130 					map->name, map->pfow_base);
131 	return 0;
132 }
133 
134 static int lpddr_chip_setup(struct map_info *map, struct lpddr_private *lpddr)
135 {
136 
137 	lpddr->qinfo = kzalloc(sizeof(struct qinfo_chip), GFP_KERNEL);
138 	if (!lpddr->qinfo)
139 		return 0;
140 
141 	/* Get the ManuID */
142 	lpddr->ManufactId = CMDVAL(map_read(map, map->pfow_base + PFOW_MANUFACTURER_ID));
143 	/* Get the DeviceID */
144 	lpddr->DevId = CMDVAL(map_read(map, map->pfow_base + PFOW_DEVICE_ID));
145 	/* read parameters from chip qinfo table */
146 	lpddr->qinfo->DevSizeShift = lpddr_info_query(map, "DevSizeShift");
147 	lpddr->qinfo->TotalBlocksNum = lpddr_info_query(map, "TotalBlocksNum");
148 	lpddr->qinfo->BufSizeShift = lpddr_info_query(map, "BufSizeShift");
149 	lpddr->qinfo->HWPartsNum = lpddr_info_query(map, "HWPartsNum");
150 	lpddr->qinfo->UniformBlockSizeShift =
151 				lpddr_info_query(map, "UniformBlockSizeShift");
152 	lpddr->qinfo->SuspEraseSupp = lpddr_info_query(map, "SuspEraseSupp");
153 	lpddr->qinfo->SingleWordProgTime =
154 				lpddr_info_query(map, "SingleWordProgTime");
155 	lpddr->qinfo->ProgBufferTime = lpddr_info_query(map, "ProgBufferTime");
156 	lpddr->qinfo->BlockEraseTime = lpddr_info_query(map, "BlockEraseTime");
157 	return 1;
158 }
159 static struct lpddr_private *lpddr_probe_chip(struct map_info *map)
160 {
161 	struct lpddr_private lpddr;
162 	struct lpddr_private *retlpddr;
163 	int numvirtchips;
164 
165 
166 	if ((map->pfow_base + 0x1000) >= map->size) {
167 		printk(KERN_NOTICE"%s Probe at base (0x%08lx) past the end of"
168 				"the map(0x%08lx)\n", map->name,
169 				(unsigned long)map->pfow_base, map->size - 1);
170 		return NULL;
171 	}
172 	memset(&lpddr, 0, sizeof(struct lpddr_private));
173 	if (!lpddr_pfow_present(map, &lpddr))
174 		return NULL;
175 
176 	if (!lpddr_chip_setup(map, &lpddr))
177 		return NULL;
178 
179 	/* Ok so we found a chip */
180 	lpddr.chipshift = lpddr.qinfo->DevSizeShift;
181 	lpddr.numchips = 1;
182 
183 	numvirtchips = lpddr.numchips * lpddr.qinfo->HWPartsNum;
184 	retlpddr = kzalloc(sizeof(struct lpddr_private) +
185 			numvirtchips * sizeof(struct flchip), GFP_KERNEL);
186 	if (!retlpddr)
187 		return NULL;
188 
189 	memcpy(retlpddr, &lpddr, sizeof(struct lpddr_private));
190 
191 	retlpddr->numchips = numvirtchips;
192 	retlpddr->chipshift = retlpddr->qinfo->DevSizeShift -
193 				__ffs(retlpddr->qinfo->HWPartsNum);
194 
195 	return retlpddr;
196 }
197 
198 struct mtd_info *lpddr_probe(struct map_info *map)
199 {
200 	struct mtd_info *mtd = NULL;
201 	struct lpddr_private *lpddr;
202 
203 	/* First probe the map to see if we havecan open PFOW here */
204 	lpddr = lpddr_probe_chip(map);
205 	if (!lpddr)
206 		return NULL;
207 
208 	map->fldrv_priv = lpddr;
209 	mtd = lpddr_cmdset(map);
210 	if (mtd) {
211 		if (mtd->size > map->size) {
212 			printk(KERN_WARNING "Reducing visibility of %ldKiB chip"
213 				"to %ldKiB\n", (unsigned long)mtd->size >> 10,
214 				(unsigned long)map->size >> 10);
215 			mtd->size = map->size;
216 		}
217 		return mtd;
218 	}
219 
220 	kfree(lpddr->qinfo);
221 	kfree(lpddr);
222 	map->fldrv_priv = NULL;
223 	return NULL;
224 }
225 
226 static struct mtd_chip_driver lpddr_chipdrv = {
227 	.probe		= lpddr_probe,
228 	.name		= "qinfo_probe",
229 	.module		= THIS_MODULE
230 };
231 
232 static int __init lpddr_probe_init(void)
233 {
234 	register_mtd_chip_driver(&lpddr_chipdrv);
235 	return 0;
236 }
237 
238 static void __exit lpddr_probe_exit(void)
239 {
240 	unregister_mtd_chip_driver(&lpddr_chipdrv);
241 }
242 
243 module_init(lpddr_probe_init);
244 module_exit(lpddr_probe_exit);
245 
246 MODULE_LICENSE("GPL");
247 MODULE_AUTHOR("Vasiliy Leonenko <vasiliy.leonenko@gmail.com>");
248 MODULE_DESCRIPTION("Driver to probe qinfo flash chips");
249 
250