1 /* $NetBSD: flash_mtdparts.c,v 1.3 2021/08/07 16:19:10 thorpej Exp $ */
2 
3 /*-
4  * Copyright (c) 2017 Jared McNeill <jmcneill@invisible.ca>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: flash_mtdparts.c,v 1.3 2021/08/07 16:19:10 thorpej Exp $");
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/device.h>
35 #include <sys/systm.h>
36 #include <sys/kmem.h>
37 
38 #include <dev/flash/flash.h>
39 
40 extern int flash_print(void *, const char *);
41 
42 static void
flash_attach_partition(struct flash_interface * flash_if,device_t parent,struct flash_partition * part)43 flash_attach_partition(struct flash_interface *flash_if, device_t parent,
44     struct flash_partition *part)
45 {
46           struct flash_attach_args faa;
47 
48           faa.flash_if = flash_if;
49           faa.partinfo = *part;
50 
51           config_found(parent, &faa, flash_print,
52               CFARGS(.iattr = "flashbus"));
53 }
54 
55 static flash_size_t
flash_parse_size(char * partdef,char ** ep)56 flash_parse_size(char *partdef, char **ep)
57 {
58           flash_size_t size;
59 
60           /* Parse the size parameter */
61           size = strtoul(partdef, ep, 10);
62           if (partdef == *ep)
63                     return 0;
64 
65           switch (**ep) {
66           case 'G':
67           case 'g':
68                     size <<= 10;
69                     /* FALLTHROUGH */
70           case 'M':
71           case 'm':
72                     size <<= 10;
73                     /* FALLTHROUGH */
74           case 'K':
75           case 'k':
76                     size <<= 10;
77                     (*ep)++;
78                     break;
79           }
80 
81           return size;
82 }
83 
84 static int
flash_parse_partdef(flash_size_t flash_size,char * partdef,flash_off_t * offset,struct flash_partition * ppart)85 flash_parse_partdef(flash_size_t flash_size, char *partdef, flash_off_t *offset,
86     struct flash_partition *ppart)
87 {
88           struct flash_partition part;
89 
90           /* Get the partition size */
91           if (*partdef == '-') {
92                     /* Use the remaining space */
93                     part.part_size = 0;
94                     partdef++;
95           } else {
96                     part.part_size = flash_parse_size(partdef, &partdef);
97                     if (part.part_size == 0)
98                               return EINVAL;
99           }
100 
101           if (*partdef == '@') {
102                     /* Explicit offset */
103                     partdef++;
104                     part.part_offset = flash_parse_size(partdef, &partdef);
105           } else {
106                     /* Offset is the end of the previous partition */
107                     part.part_offset = *offset;
108           }
109 
110           /* Calculate partition size for "all remaining space" parts */
111           if (part.part_size == 0)
112                     part.part_size = flash_size - part.part_offset;
113 
114           if (*partdef == '(') {
115                     /* Partition name */
116                     partdef++;
117                     part.part_name = partdef;
118                     partdef = strchr(partdef, ')');
119                     if (partdef == NULL)
120                               return EINVAL;
121                     *partdef = '\0';
122                     partdef++;
123           }
124 
125           part.part_flags = 0;
126           if (strncmp(partdef, "ro", 2) == 0) {
127                     part.part_flags |= FLASH_PART_READONLY;
128                     partdef += 2;
129           }
130 
131           *ppart = part;
132 
133           *offset = part.part_offset + part.part_size;
134 
135           return 0;
136 }
137 
138 static void
flash_parse_mtddef(struct flash_interface * flash_if,device_t parent,flash_size_t flash_size,char * mtddef)139 flash_parse_mtddef(struct flash_interface *flash_if, device_t parent,
140     flash_size_t flash_size, char *mtddef)
141 {
142           struct flash_partition part;
143           char *partdef = mtddef, *nextdef;
144           flash_off_t offset = 0;
145           int error;
146 
147           while (partdef && offset < flash_size) {
148                     /* Find the end */
149                     nextdef = strchr(partdef, ',');
150                     if (nextdef == NULL)
151                         nextdef = strchr(partdef, ' ');
152                     if (nextdef)
153                               *nextdef++ = '\0';
154 
155                     error = flash_parse_partdef(flash_size, partdef, &offset,
156                         &part);
157                     if (error) {
158                               aprint_error_dev(parent, "bad partition def '%s'\n",
159                                   partdef);
160                               return;
161                     }
162 
163                     flash_attach_partition(flash_if, parent, &part);
164 
165                     partdef = nextdef;
166           }
167 }
168 
169 /*
170  * Attach partitions to a given parent device node that match the supplied
171  * device id. The cmdline follows the following format:
172  *
173  * mtdparts=<mtddef>[;<mtddef]
174  * <mtddef>  := <mtd-id>:<partdef>[,<partdef>]
175  * <partdef> := <size>[@offset][<name>][ro]
176  * <mtd-id>  := unique id used in mapping driver/device (number of flash bank)
177  * <size>    := memsize OR "-" to denote all remaining space
178  * <name>    := '(' NAME ')'
179  */
180 void
flash_attach_mtdparts(struct flash_interface * flash_if,device_t parent,flash_size_t flash_size,const char * mtd_id,const char * cmdline)181 flash_attach_mtdparts(struct flash_interface *flash_if, device_t parent,
182     flash_size_t flash_size, const char *mtd_id, const char *cmdline)
183 {
184           char *mtddef;
185           size_t mtddeflen;
186 
187           /* Find the definition for our mtd id */
188           const char *s = strstr(cmdline, mtd_id);
189           if (s == NULL || s[strlen(mtd_id)] != ':')
190                     return;
191 
192           mtddef = kmem_strdupsize(s + strlen(mtd_id) + 1, &mtddeflen, KM_SLEEP);
193 
194           flash_parse_mtddef(flash_if, parent, flash_size, mtddef);
195 
196           kmem_free(mtddef, mtddeflen);
197 }
198