xref: /linux/drivers/mtd/lpddr/qinfo_probe.c (revision 58e16d792a6a8c6b750f637a4649967fcac853dc)
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