xref: /openbmc/linux/drivers/mtd/lpddr/qinfo_probe.c (revision 33a03aad)
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 		printk(KERN_WARNING "%s: no memory for LPDDR qinfo structure\n",
140 				map->name);
141 		return 0;
142 	}
143 
144 	/* Get the ManuID */
145 	lpddr->ManufactId = CMDVAL(map_read(map, map->pfow_base + PFOW_MANUFACTURER_ID));
146 	/* Get the DeviceID */
147 	lpddr->DevId = CMDVAL(map_read(map, map->pfow_base + PFOW_DEVICE_ID));
148 	/* read parameters from chip qinfo table */
149 	lpddr->qinfo->DevSizeShift = lpddr_info_query(map, "DevSizeShift");
150 	lpddr->qinfo->TotalBlocksNum = lpddr_info_query(map, "TotalBlocksNum");
151 	lpddr->qinfo->BufSizeShift = lpddr_info_query(map, "BufSizeShift");
152 	lpddr->qinfo->HWPartsNum = lpddr_info_query(map, "HWPartsNum");
153 	lpddr->qinfo->UniformBlockSizeShift =
154 				lpddr_info_query(map, "UniformBlockSizeShift");
155 	lpddr->qinfo->SuspEraseSupp = lpddr_info_query(map, "SuspEraseSupp");
156 	lpddr->qinfo->SingleWordProgTime =
157 				lpddr_info_query(map, "SingleWordProgTime");
158 	lpddr->qinfo->ProgBufferTime = lpddr_info_query(map, "ProgBufferTime");
159 	lpddr->qinfo->BlockEraseTime = lpddr_info_query(map, "BlockEraseTime");
160 	return 1;
161 }
162 static struct lpddr_private *lpddr_probe_chip(struct map_info *map)
163 {
164 	struct lpddr_private lpddr;
165 	struct lpddr_private *retlpddr;
166 	int numvirtchips;
167 
168 
169 	if ((map->pfow_base + 0x1000) >= map->size) {
170 		printk(KERN_NOTICE"%s Probe at base (0x%08lx) past the end of"
171 				"the map(0x%08lx)\n", map->name,
172 				(unsigned long)map->pfow_base, map->size - 1);
173 		return NULL;
174 	}
175 	memset(&lpddr, 0, sizeof(struct lpddr_private));
176 	if (!lpddr_pfow_present(map, &lpddr))
177 		return NULL;
178 
179 	if (!lpddr_chip_setup(map, &lpddr))
180 		return NULL;
181 
182 	/* Ok so we found a chip */
183 	lpddr.chipshift = lpddr.qinfo->DevSizeShift;
184 	lpddr.numchips = 1;
185 
186 	numvirtchips = lpddr.numchips * lpddr.qinfo->HWPartsNum;
187 	retlpddr = kzalloc(sizeof(struct lpddr_private) +
188 			numvirtchips * sizeof(struct flchip), GFP_KERNEL);
189 	if (!retlpddr)
190 		return NULL;
191 
192 	memcpy(retlpddr, &lpddr, sizeof(struct lpddr_private));
193 
194 	retlpddr->numchips = numvirtchips;
195 	retlpddr->chipshift = retlpddr->qinfo->DevSizeShift -
196 				__ffs(retlpddr->qinfo->HWPartsNum);
197 
198 	return retlpddr;
199 }
200 
201 struct mtd_info *lpddr_probe(struct map_info *map)
202 {
203 	struct mtd_info *mtd = NULL;
204 	struct lpddr_private *lpddr;
205 
206 	/* First probe the map to see if we havecan open PFOW here */
207 	lpddr = lpddr_probe_chip(map);
208 	if (!lpddr)
209 		return NULL;
210 
211 	map->fldrv_priv = lpddr;
212 	mtd = lpddr_cmdset(map);
213 	if (mtd) {
214 		if (mtd->size > map->size) {
215 			printk(KERN_WARNING "Reducing visibility of %ldKiB chip"
216 				"to %ldKiB\n", (unsigned long)mtd->size >> 10,
217 				(unsigned long)map->size >> 10);
218 			mtd->size = map->size;
219 		}
220 		return mtd;
221 	}
222 
223 	kfree(lpddr->qinfo);
224 	kfree(lpddr);
225 	map->fldrv_priv = NULL;
226 	return NULL;
227 }
228 
229 static struct mtd_chip_driver lpddr_chipdrv = {
230 	.probe		= lpddr_probe,
231 	.name		= "qinfo_probe",
232 	.module		= THIS_MODULE
233 };
234 
235 static int __init lpddr_probe_init(void)
236 {
237 	register_mtd_chip_driver(&lpddr_chipdrv);
238 	return 0;
239 }
240 
241 static void __exit lpddr_probe_exit(void)
242 {
243 	unregister_mtd_chip_driver(&lpddr_chipdrv);
244 }
245 
246 module_init(lpddr_probe_init);
247 module_exit(lpddr_probe_exit);
248 
249 MODULE_LICENSE("GPL");
250 MODULE_AUTHOR("Vasiliy Leonenko <vasiliy.leonenko@gmail.com>");
251 MODULE_DESCRIPTION("Driver to probe qinfo flash chips");
252 
253