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 */
42static 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(c: *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 */
93static 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, set the version or revision to an invalid
129 * value and emit an informal message. Continue probing because the
130 * product information is not critical for the driver to operate.
131 */
132void es58x_parse_product_info(struct es58x_device *es58x_dev)
133{
134 static const struct es58x_sw_version sw_version_not_set = {
135 .major = -1,
136 .minor = -1,
137 .revision = -1,
138 };
139 static const struct es58x_hw_revision hw_revision_not_set = {
140 .letter = '\0',
141 .major = -1,
142 .minor = -1,
143 };
144 char *prod_info;
145
146 es58x_dev->firmware_version = sw_version_not_set;
147 es58x_dev->bootloader_version = sw_version_not_set;
148 es58x_dev->hardware_revision = hw_revision_not_set;
149
150 prod_info = usb_cache_string(udev: es58x_dev->udev, ES58X_PROD_INFO_IDX);
151 if (!prod_info) {
152 dev_warn(es58x_dev->dev,
153 "could not retrieve the product info string\n");
154 return;
155 }
156
157 if (es58x_parse_sw_version(es58x_dev, prod_info, prefix: "FW") ||
158 es58x_parse_sw_version(es58x_dev, prod_info, prefix: "BL") ||
159 es58x_parse_hw_rev(es58x_dev, prod_info))
160 dev_info(es58x_dev->dev,
161 "could not parse product info: '%s'\n", prod_info);
162
163 kfree(objp: prod_info);
164}
165
166/**
167 * es58x_sw_version_is_valid() - Check if the version is a valid number.
168 * @sw_ver: Version number of either the firmware or the bootloader.
169 *
170 * If any of the software version sub-numbers do not fit on two
171 * digits, the version is invalid, most probably because the product
172 * string could not be parsed.
173 *
174 * Return: @true if the software version is valid, @false otherwise.
175 */
176static inline bool es58x_sw_version_is_valid(struct es58x_sw_version *sw_ver)
177{
178 return sw_ver->major < 100 && sw_ver->minor < 100 &&
179 sw_ver->revision < 100;
180}
181
182/**
183 * es58x_hw_revision_is_valid() - Check if the revision is a valid number.
184 * @hw_rev: Revision number of the hardware.
185 *
186 * If &es58x_hw_revision.letter is not a alphanumeric character or if
187 * any of the hardware revision sub-numbers do not fit on three
188 * digits, the revision is invalid, most probably because the product
189 * string could not be parsed.
190 *
191 * Return: @true if the hardware revision is valid, @false otherwise.
192 */
193static inline bool es58x_hw_revision_is_valid(struct es58x_hw_revision *hw_rev)
194{
195 return isalnum(hw_rev->letter) && hw_rev->major < 1000 &&
196 hw_rev->minor < 1000;
197}
198
199/**
200 * es58x_devlink_info_get() - Report the product information.
201 * @devlink: Devlink.
202 * @req: skb wrapper where to put requested information.
203 * @extack: Unused.
204 *
205 * Report the firmware version, the bootloader version, the hardware
206 * revision and the serial number through netlink.
207 *
208 * Return: zero on success, errno when any error occurs.
209 */
210static int es58x_devlink_info_get(struct devlink *devlink,
211 struct devlink_info_req *req,
212 struct netlink_ext_ack *extack)
213{
214 struct es58x_device *es58x_dev = devlink_priv(devlink);
215 struct es58x_sw_version *fw_ver = &es58x_dev->firmware_version;
216 struct es58x_sw_version *bl_ver = &es58x_dev->bootloader_version;
217 struct es58x_hw_revision *hw_rev = &es58x_dev->hardware_revision;
218 char buf[max(sizeof("xx.xx.xx"), sizeof("axxx/xxx"))];
219 int ret = 0;
220
221 if (es58x_sw_version_is_valid(sw_ver: fw_ver)) {
222 snprintf(buf, size: sizeof(buf), fmt: "%02u.%02u.%02u",
223 fw_ver->major, fw_ver->minor, fw_ver->revision);
224 ret = devlink_info_version_running_put(req,
225 DEVLINK_INFO_VERSION_GENERIC_FW,
226 version_value: buf);
227 if (ret)
228 return ret;
229 }
230
231 if (es58x_sw_version_is_valid(sw_ver: bl_ver)) {
232 snprintf(buf, size: sizeof(buf), fmt: "%02u.%02u.%02u",
233 bl_ver->major, bl_ver->minor, bl_ver->revision);
234 ret = devlink_info_version_running_put(req,
235 DEVLINK_INFO_VERSION_GENERIC_FW_BOOTLOADER,
236 version_value: buf);
237 if (ret)
238 return ret;
239 }
240
241 if (es58x_hw_revision_is_valid(hw_rev)) {
242 snprintf(buf, size: sizeof(buf), fmt: "%c%03u/%03u",
243 hw_rev->letter, hw_rev->major, hw_rev->minor);
244 ret = devlink_info_version_fixed_put(req,
245 DEVLINK_INFO_VERSION_GENERIC_BOARD_REV,
246 version_value: buf);
247 if (ret)
248 return ret;
249 }
250
251 return devlink_info_serial_number_put(req, sn: es58x_dev->udev->serial);
252}
253
254const struct devlink_ops es58x_dl_ops = {
255 .info_get = es58x_devlink_info_get,
256};
257

source code of linux/drivers/net/can/usb/etas_es58x/es58x_devlink.c