1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Probing flash chips with QINFO records.
4  * (C) 2008 Korolev Alexey <akorolev@infradead.org>
5  * (C) 2008 Vasiliy Leonenko <vasiliy.leonenko@gmail.com>
6  */
7 #include <linux/module.h>
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/errno.h>
12 #include <linux/slab.h>
13 #include <linux/interrupt.h>
14 
15 #include <linux/mtd/xip.h>
16 #include <linux/mtd/map.h>
17 #include <linux/mtd/pfow.h>
18 #include <linux/mtd/qinfo.h>
19 
20 static int lpddr_chip_setup(struct map_info *map, struct lpddr_private *lpddr);
21 struct mtd_info *lpddr_probe(struct map_info *map);
22 static struct lpddr_private *lpddr_probe_chip(struct map_info *map);
23 static int lpddr_pfow_present(struct map_info *map,
24 			struct lpddr_private *lpddr);
25 
26 static struct qinfo_query_info qinfo_array[] = {
27 	/* General device info */
28 	{0, 0, "DevSizeShift", "Device size 2^n bytes"},
29 	{0, 3, "BufSizeShift", "Program buffer size 2^n bytes"},
30 	/* Erase block information */
31 	{1, 1, "TotalBlocksNum", "Total number of blocks"},
32 	{1, 2, "UniformBlockSizeShift", "Uniform block size 2^n bytes"},
33 	/* Partition information */
34 	{2, 1, "HWPartsNum", "Number of hardware partitions"},
35 	/* Optional features */
36 	{5, 1, "SuspEraseSupp", "Suspend erase supported"},
37 	/* Operation typical time */
38 	{10, 0, "SingleWordProgTime", "Single word program 2^n u-sec"},
39 	{10, 1, "ProgBufferTime", "Program buffer write 2^n u-sec"},
40 	{10, 2, "BlockEraseTime", "Block erase 2^n m-sec"},
41 	{10, 3, "FullChipEraseTime", "Full chip erase 2^n m-sec"},
42 };
43 
lpddr_get_qinforec_pos(struct map_info * map,char * id_str)44 static long lpddr_get_qinforec_pos(struct map_info *map, char *id_str)
45 {
46 	int qinfo_lines = ARRAY_SIZE(qinfo_array);
47 	int i;
48 	int bankwidth = map_bankwidth(map) * 8;
49 	int major, minor;
50 
51 	for (i = 0; i < qinfo_lines; i++) {
52 		if (strcmp(id_str, qinfo_array[i].id_str) == 0) {
53 			major = qinfo_array[i].major & ((1 << bankwidth) - 1);
54 			minor = qinfo_array[i].minor & ((1 << bankwidth) - 1);
55 			return minor | (major << bankwidth);
56 		}
57 	}
58 	printk(KERN_ERR"%s qinfo id string is wrong! \n", map->name);
59 	BUG();
60 	return -1;
61 }
62 
lpddr_info_query(struct map_info * map,char * id_str)63 static uint16_t lpddr_info_query(struct map_info *map, char *id_str)
64 {
65 	unsigned int dsr, val;
66 	int bits_per_chip = map_bankwidth(map) * 8;
67 	unsigned long adr = lpddr_get_qinforec_pos(map, id_str);
68 	int attempts = 20;
69 
70 	/* Write a request for the PFOW record */
71 	map_write(map, CMD(LPDDR_INFO_QUERY),
72 			map->pfow_base + PFOW_COMMAND_CODE);
73 	map_write(map, CMD(adr & ((1 << bits_per_chip) - 1)),
74 			map->pfow_base + PFOW_COMMAND_ADDRESS_L);
75 	map_write(map, CMD(adr >> bits_per_chip),
76 			map->pfow_base + PFOW_COMMAND_ADDRESS_H);
77 	map_write(map, CMD(LPDDR_START_EXECUTION),
78 			map->pfow_base + PFOW_COMMAND_EXECUTE);
79 
80 	while ((attempts--) > 0) {
81 		dsr = CMDVAL(map_read(map, map->pfow_base + PFOW_DSR));
82 		if (dsr & DSR_READY_STATUS)
83 			break;
84 		udelay(10);
85 	}
86 
87 	val = CMDVAL(map_read(map, map->pfow_base + PFOW_COMMAND_DATA));
88 	return val;
89 }
90 
lpddr_pfow_present(struct map_info * map,struct lpddr_private * lpddr)91 static int lpddr_pfow_present(struct map_info *map, struct lpddr_private *lpddr)
92 {
93 	map_word pfow_val[4];
94 
95 	/* Check identification string */
96 	pfow_val[0] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_P);
97 	pfow_val[1] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_F);
98 	pfow_val[2] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_O);
99 	pfow_val[3] = map_read(map, map->pfow_base + PFOW_QUERY_STRING_W);
100 
101 	if (!map_word_equal(map, CMD('P'), pfow_val[0]))
102 		goto out;
103 
104 	if (!map_word_equal(map, CMD('F'), pfow_val[1]))
105 		goto out;
106 
107 	if (!map_word_equal(map, CMD('O'), pfow_val[2]))
108 		goto out;
109 
110 	if (!map_word_equal(map, CMD('W'), pfow_val[3]))
111 		goto out;
112 
113 	return 1;	/* "PFOW" is found */
114 out:
115 	printk(KERN_WARNING"%s: PFOW string at 0x%lx is not found \n",
116 					map->name, map->pfow_base);
117 	return 0;
118 }
119 
lpddr_chip_setup(struct map_info * map,struct lpddr_private * lpddr)120 static int lpddr_chip_setup(struct map_info *map, struct lpddr_private *lpddr)
121 {
122 
123 	lpddr->qinfo = kzalloc(sizeof(struct qinfo_chip), GFP_KERNEL);
124 	if (!lpddr->qinfo)
125 		return 0;
126 
127 	/* Get the ManuID */
128 	lpddr->ManufactId = CMDVAL(map_read(map, map->pfow_base + PFOW_MANUFACTURER_ID));
129 	/* Get the DeviceID */
130 	lpddr->DevId = CMDVAL(map_read(map, map->pfow_base + PFOW_DEVICE_ID));
131 	/* read parameters from chip qinfo table */
132 	lpddr->qinfo->DevSizeShift = lpddr_info_query(map, "DevSizeShift");
133 	lpddr->qinfo->TotalBlocksNum = lpddr_info_query(map, "TotalBlocksNum");
134 	lpddr->qinfo->BufSizeShift = lpddr_info_query(map, "BufSizeShift");
135 	lpddr->qinfo->HWPartsNum = lpddr_info_query(map, "HWPartsNum");
136 	lpddr->qinfo->UniformBlockSizeShift =
137 				lpddr_info_query(map, "UniformBlockSizeShift");
138 	lpddr->qinfo->SuspEraseSupp = lpddr_info_query(map, "SuspEraseSupp");
139 	lpddr->qinfo->SingleWordProgTime =
140 				lpddr_info_query(map, "SingleWordProgTime");
141 	lpddr->qinfo->ProgBufferTime = lpddr_info_query(map, "ProgBufferTime");
142 	lpddr->qinfo->BlockEraseTime = lpddr_info_query(map, "BlockEraseTime");
143 	return 1;
144 }
lpddr_probe_chip(struct map_info * map)145 static struct lpddr_private *lpddr_probe_chip(struct map_info *map)
146 {
147 	struct lpddr_private lpddr;
148 	struct lpddr_private *retlpddr;
149 	int numvirtchips;
150 
151 
152 	if ((map->pfow_base + 0x1000) >= map->size) {
153 		printk(KERN_NOTICE"%s Probe at base (0x%08lx) past the end of"
154 				"the map(0x%08lx)\n", map->name,
155 				(unsigned long)map->pfow_base, map->size - 1);
156 		return NULL;
157 	}
158 	memset(&lpddr, 0, sizeof(struct lpddr_private));
159 	if (!lpddr_pfow_present(map, &lpddr))
160 		return NULL;
161 
162 	if (!lpddr_chip_setup(map, &lpddr))
163 		return NULL;
164 
165 	/* Ok so we found a chip */
166 	lpddr.chipshift = lpddr.qinfo->DevSizeShift;
167 	lpddr.numchips = 1;
168 
169 	numvirtchips = lpddr.numchips * lpddr.qinfo->HWPartsNum;
170 	retlpddr = kzalloc(struct_size(retlpddr, chips, numvirtchips),
171 			   GFP_KERNEL);
172 	if (!retlpddr)
173 		return NULL;
174 
175 	memcpy(retlpddr, &lpddr, sizeof(struct lpddr_private));
176 
177 	retlpddr->numchips = numvirtchips;
178 	retlpddr->chipshift = retlpddr->qinfo->DevSizeShift -
179 				__ffs(retlpddr->qinfo->HWPartsNum);
180 
181 	return retlpddr;
182 }
183 
lpddr_probe(struct map_info * map)184 struct mtd_info *lpddr_probe(struct map_info *map)
185 {
186 	struct mtd_info *mtd = NULL;
187 	struct lpddr_private *lpddr;
188 
189 	/* First probe the map to see if we havecan open PFOW here */
190 	lpddr = lpddr_probe_chip(map);
191 	if (!lpddr)
192 		return NULL;
193 
194 	map->fldrv_priv = lpddr;
195 	mtd = lpddr_cmdset(map);
196 	if (mtd) {
197 		if (mtd->size > map->size) {
198 			printk(KERN_WARNING "Reducing visibility of %ldKiB chip"
199 				"to %ldKiB\n", (unsigned long)mtd->size >> 10,
200 				(unsigned long)map->size >> 10);
201 			mtd->size = map->size;
202 		}
203 		return mtd;
204 	}
205 
206 	kfree(lpddr->qinfo);
207 	kfree(lpddr);
208 	map->fldrv_priv = NULL;
209 	return NULL;
210 }
211 
212 static struct mtd_chip_driver lpddr_chipdrv = {
213 	.probe		= lpddr_probe,
214 	.name		= "qinfo_probe",
215 	.module		= THIS_MODULE
216 };
217 
lpddr_probe_init(void)218 static int __init lpddr_probe_init(void)
219 {
220 	register_mtd_chip_driver(&lpddr_chipdrv);
221 	return 0;
222 }
223 
lpddr_probe_exit(void)224 static void __exit lpddr_probe_exit(void)
225 {
226 	unregister_mtd_chip_driver(&lpddr_chipdrv);
227 }
228 
229 module_init(lpddr_probe_init);
230 module_exit(lpddr_probe_exit);
231 
232 MODULE_LICENSE("GPL");
233 MODULE_AUTHOR("Vasiliy Leonenko <vasiliy.leonenko@gmail.com>");
234 MODULE_DESCRIPTION("Driver to probe qinfo flash chips");
235 
236