1 // SPDX-License-Identifier: GPL-2.0
2
3 /* Driver for ETAS GmbH ES58X USB CAN(-FD) Bus Interfaces.
4 *
5 * File es58x_devlink.c: report the product information using devlink.
6 *
7 * Copyright (c) 2022 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
8 */
9
10 #include <linux/ctype.h>
11 #include <linux/device.h>
12 #include <linux/usb.h>
13 #include <net/devlink.h>
14
15 #include "es58x_core.h"
16
17 /* USB descriptor index containing the product information string. */
18 #define ES58X_PROD_INFO_IDX 6
19
20 /**
21 * es58x_parse_sw_version() - Extract boot loader or firmware version.
22 * @es58x_dev: ES58X device.
23 * @prod_info: USB custom string returned by the device.
24 * @prefix: Select which information should be parsed. Set it to "FW"
25 * to parse the firmware version or to "BL" to parse the
26 * bootloader version.
27 *
28 * The @prod_info string contains the firmware and the bootloader
29 * version number all prefixed by a magic string and concatenated with
30 * other numbers. Depending on the device, the firmware (bootloader)
31 * format is either "FW_Vxx.xx.xx" ("BL_Vxx.xx.xx") or "FW:xx.xx.xx"
32 * ("BL:xx.xx.xx") where 'x' represents a digit. @prod_info must
33 * contains the common part of those prefixes: "FW" or "BL".
34 *
35 * Parse @prod_info and store the version number in
36 * &es58x_dev.firmware_version or &es58x_dev.bootloader_version
37 * according to @prefix value.
38 *
39 * Return: zero on success, -EINVAL if @prefix contains an invalid
40 * value and -EBADMSG if @prod_info could not be parsed.
41 */
es58x_parse_sw_version(struct es58x_device * es58x_dev,const char * prod_info,const char * prefix)42 static int es58x_parse_sw_version(struct es58x_device *es58x_dev,
43 const char *prod_info, const char *prefix)
44 {
45 struct es58x_sw_version *version;
46 int major, minor, revision;
47
48 if (!strcmp(prefix, "FW"))
49 version = &es58x_dev->firmware_version;
50 else if (!strcmp(prefix, "BL"))
51 version = &es58x_dev->bootloader_version;
52 else
53 return -EINVAL;
54
55 /* Go to prefix */
56 prod_info = strstr(prod_info, prefix);
57 if (!prod_info)
58 return -EBADMSG;
59 /* Go to beginning of the version number */
60 while (!isdigit(*prod_info)) {
61 prod_info++;
62 if (!*prod_info)
63 return -EBADMSG;
64 }
65
66 if (sscanf(prod_info, "%2u.%2u.%2u", &major, &minor, &revision) != 3)
67 return -EBADMSG;
68
69 version->major = major;
70 version->minor = minor;
71 version->revision = revision;
72
73 return 0;
74 }
75
76 /**
77 * es58x_parse_hw_rev() - Extract hardware revision number.
78 * @es58x_dev: ES58X device.
79 * @prod_info: USB custom string returned by the device.
80 *
81 * @prod_info contains the hardware revision prefixed by a magic
82 * string and conquenated together with other numbers. Depending on
83 * the device, the hardware revision format is either
84 * "HW_VER:axxx/xxx" or "HR:axxx/xxx" where 'a' represents a letter
85 * and 'x' a digit.
86 *
87 * Parse @prod_info and store the hardware revision number in
88 * &es58x_dev.hardware_revision.
89 *
90 * Return: zero on success, -EBADMSG if @prod_info could not be
91 * parsed.
92 */
es58x_parse_hw_rev(struct es58x_device * es58x_dev,const char * prod_info)93 static int es58x_parse_hw_rev(struct es58x_device *es58x_dev,
94 const char *prod_info)
95 {
96 char letter;
97 int major, minor;
98
99 /* The only occurrence of 'H' is in the hardware revision prefix. */
100 prod_info = strchr(prod_info, 'H');
101 if (!prod_info)
102 return -EBADMSG;
103 /* Go to beginning of the hardware revision */
104 prod_info = strchr(prod_info, ':');
105 if (!prod_info)
106 return -EBADMSG;
107 prod_info++;
108
109 if (sscanf(prod_info, "%c%3u/%3u", &letter, &major, &minor) != 3)
110 return -EBADMSG;
111
112 es58x_dev->hardware_revision.letter = letter;
113 es58x_dev->hardware_revision.major = major;
114 es58x_dev->hardware_revision.minor = minor;
115
116 return 0;
117 }
118
119 /**
120 * es58x_parse_product_info() - Parse the ES58x product information
121 * string.
122 * @es58x_dev: ES58X device.
123 *
124 * Retrieve the product information string and parse it to extract the
125 * firmware version, the bootloader version and the hardware
126 * revision.
127 *
128 * If the function fails, simply emit a log message and continue
129 * because product information is not critical for the driver to
130 * operate.
131 */
es58x_parse_product_info(struct es58x_device * es58x_dev)132 void es58x_parse_product_info(struct es58x_device *es58x_dev)
133 {
134 char *prod_info;
135
136 prod_info = usb_cache_string(es58x_dev->udev, ES58X_PROD_INFO_IDX);
137 if (!prod_info) {
138 dev_warn(es58x_dev->dev,
139 "could not retrieve the product info string\n");
140 return;
141 }
142
143 if (es58x_parse_sw_version(es58x_dev, prod_info, "FW") ||
144 es58x_parse_sw_version(es58x_dev, prod_info, "BL") ||
145 es58x_parse_hw_rev(es58x_dev, prod_info))
146 dev_info(es58x_dev->dev,
147 "could not parse product info: '%s'\n", prod_info);
148
149 kfree(prod_info);
150 }
151
152 /**
153 * es58x_sw_version_is_set() - Check if the version is a valid number.
154 * @sw_ver: Version number of either the firmware or the bootloader.
155 *
156 * If &es58x_sw_version.major, &es58x_sw_version.minor and
157 * &es58x_sw_version.revision are all zero, the product string could
158 * not be parsed and the version number is invalid.
159 */
es58x_sw_version_is_set(struct es58x_sw_version * sw_ver)160 static inline bool es58x_sw_version_is_set(struct es58x_sw_version *sw_ver)
161 {
162 return sw_ver->major || sw_ver->minor || sw_ver->revision;
163 }
164
165 /**
166 * es58x_hw_revision_is_set() - Check if the revision is a valid number.
167 * @hw_rev: Revision number of the hardware.
168 *
169 * If &es58x_hw_revision.letter is the null character, the product
170 * string could not be parsed and the hardware revision number is
171 * invalid.
172 */
es58x_hw_revision_is_set(struct es58x_hw_revision * hw_rev)173 static inline bool es58x_hw_revision_is_set(struct es58x_hw_revision *hw_rev)
174 {
175 return hw_rev->letter != '\0';
176 }
177
178 /**
179 * es58x_devlink_info_get() - Report the product information.
180 * @devlink: Devlink.
181 * @req: skb wrapper where to put requested information.
182 * @extack: Unused.
183 *
184 * Report the firmware version, the bootloader version, the hardware
185 * revision and the serial number through netlink.
186 *
187 * Return: zero on success, errno when any error occurs.
188 */
es58x_devlink_info_get(struct devlink * devlink,struct devlink_info_req * req,struct netlink_ext_ack * extack)189 static int es58x_devlink_info_get(struct devlink *devlink,
190 struct devlink_info_req *req,
191 struct netlink_ext_ack *extack)
192 {
193 struct es58x_device *es58x_dev = devlink_priv(devlink);
194 struct es58x_sw_version *fw_ver = &es58x_dev->firmware_version;
195 struct es58x_sw_version *bl_ver = &es58x_dev->bootloader_version;
196 struct es58x_hw_revision *hw_rev = &es58x_dev->hardware_revision;
197 char buf[max(sizeof("xx.xx.xx"), sizeof("axxx/xxx"))];
198 int ret = 0;
199
200 if (es58x_sw_version_is_set(fw_ver)) {
201 snprintf(buf, sizeof(buf), "%02u.%02u.%02u",
202 fw_ver->major, fw_ver->minor, fw_ver->revision);
203 ret = devlink_info_version_running_put(req,
204 DEVLINK_INFO_VERSION_GENERIC_FW,
205 buf);
206 if (ret)
207 return ret;
208 }
209
210 if (es58x_sw_version_is_set(bl_ver)) {
211 snprintf(buf, sizeof(buf), "%02u.%02u.%02u",
212 bl_ver->major, bl_ver->minor, bl_ver->revision);
213 ret = devlink_info_version_running_put(req,
214 DEVLINK_INFO_VERSION_GENERIC_FW_BOOTLOADER,
215 buf);
216 if (ret)
217 return ret;
218 }
219
220 if (es58x_hw_revision_is_set(hw_rev)) {
221 snprintf(buf, sizeof(buf), "%c%03u/%03u",
222 hw_rev->letter, hw_rev->major, hw_rev->minor);
223 ret = devlink_info_version_fixed_put(req,
224 DEVLINK_INFO_VERSION_GENERIC_BOARD_REV,
225 buf);
226 if (ret)
227 return ret;
228 }
229
230 return devlink_info_serial_number_put(req, es58x_dev->udev->serial);
231 }
232
233 const struct devlink_ops es58x_dl_ops = {
234 .info_get = es58x_devlink_info_get,
235 };
236
