xref: /openbmc/linux/drivers/platform/chrome/cros_ec_sysfs.c (revision 93707cbabcc8baf2b2b5f4a99c1f08ee83eb7abd)
1 /*
2  * cros_ec_sysfs - expose the Chrome OS EC through sysfs
3  *
4  * Copyright (C) 2014 Google, Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program. If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #define pr_fmt(fmt) "cros_ec_sysfs: " fmt
21 
22 #include <linux/ctype.h>
23 #include <linux/delay.h>
24 #include <linux/device.h>
25 #include <linux/fs.h>
26 #include <linux/kobject.h>
27 #include <linux/mfd/cros_ec.h>
28 #include <linux/mfd/cros_ec_commands.h>
29 #include <linux/module.h>
30 #include <linux/platform_device.h>
31 #include <linux/printk.h>
32 #include <linux/slab.h>
33 #include <linux/stat.h>
34 #include <linux/types.h>
35 #include <linux/uaccess.h>
36 
37 /* Accessor functions */
38 
39 static ssize_t show_ec_reboot(struct device *dev,
40 			      struct device_attribute *attr, char *buf)
41 {
42 	int count = 0;
43 
44 	count += scnprintf(buf + count, PAGE_SIZE - count,
45 			   "ro|rw|cancel|cold|disable-jump|hibernate");
46 	count += scnprintf(buf + count, PAGE_SIZE - count,
47 			   " [at-shutdown]\n");
48 	return count;
49 }
50 
51 static ssize_t store_ec_reboot(struct device *dev,
52 			       struct device_attribute *attr,
53 			       const char *buf, size_t count)
54 {
55 	static const struct {
56 		const char * const str;
57 		uint8_t cmd;
58 		uint8_t flags;
59 	} words[] = {
60 		{"cancel",       EC_REBOOT_CANCEL, 0},
61 		{"ro",           EC_REBOOT_JUMP_RO, 0},
62 		{"rw",           EC_REBOOT_JUMP_RW, 0},
63 		{"cold",         EC_REBOOT_COLD, 0},
64 		{"disable-jump", EC_REBOOT_DISABLE_JUMP, 0},
65 		{"hibernate",    EC_REBOOT_HIBERNATE, 0},
66 		{"at-shutdown",  -1, EC_REBOOT_FLAG_ON_AP_SHUTDOWN},
67 	};
68 	struct cros_ec_command *msg;
69 	struct ec_params_reboot_ec *param;
70 	int got_cmd = 0, offset = 0;
71 	int i;
72 	int ret;
73 	struct cros_ec_dev *ec = container_of(dev,
74 					      struct cros_ec_dev, class_dev);
75 
76 	msg = kmalloc(sizeof(*msg) + sizeof(*param), GFP_KERNEL);
77 	if (!msg)
78 		return -ENOMEM;
79 
80 	param = (struct ec_params_reboot_ec *)msg->data;
81 
82 	param->flags = 0;
83 	while (1) {
84 		/* Find word to start scanning */
85 		while (buf[offset] && isspace(buf[offset]))
86 			offset++;
87 		if (!buf[offset])
88 			break;
89 
90 		for (i = 0; i < ARRAY_SIZE(words); i++) {
91 			if (!strncasecmp(words[i].str, buf+offset,
92 					 strlen(words[i].str))) {
93 				if (words[i].flags) {
94 					param->flags |= words[i].flags;
95 				} else {
96 					param->cmd = words[i].cmd;
97 					got_cmd = 1;
98 				}
99 				break;
100 			}
101 		}
102 
103 		/* On to the next word, if any */
104 		while (buf[offset] && !isspace(buf[offset]))
105 			offset++;
106 	}
107 
108 	if (!got_cmd) {
109 		count = -EINVAL;
110 		goto exit;
111 	}
112 
113 	msg->version = 0;
114 	msg->command = EC_CMD_REBOOT_EC + ec->cmd_offset;
115 	msg->outsize = sizeof(*param);
116 	msg->insize = 0;
117 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
118 	if (ret < 0) {
119 		count = ret;
120 		goto exit;
121 	}
122 	if (msg->result != EC_RES_SUCCESS) {
123 		dev_dbg(ec->dev, "EC result %d\n", msg->result);
124 		count = -EINVAL;
125 	}
126 exit:
127 	kfree(msg);
128 	return count;
129 }
130 
131 static ssize_t show_ec_version(struct device *dev,
132 			       struct device_attribute *attr, char *buf)
133 {
134 	static const char * const image_names[] = {"unknown", "RO", "RW"};
135 	struct ec_response_get_version *r_ver;
136 	struct ec_response_get_chip_info *r_chip;
137 	struct ec_response_board_version *r_board;
138 	struct cros_ec_command *msg;
139 	int ret;
140 	int count = 0;
141 	struct cros_ec_dev *ec = container_of(dev,
142 					      struct cros_ec_dev, class_dev);
143 
144 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
145 	if (!msg)
146 		return -ENOMEM;
147 
148 	/* Get versions. RW may change. */
149 	msg->version = 0;
150 	msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
151 	msg->insize = sizeof(*r_ver);
152 	msg->outsize = 0;
153 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
154 	if (ret < 0) {
155 		count = ret;
156 		goto exit;
157 	}
158 	if (msg->result != EC_RES_SUCCESS) {
159 		count = scnprintf(buf, PAGE_SIZE,
160 				  "ERROR: EC returned %d\n", msg->result);
161 		goto exit;
162 	}
163 
164 	r_ver = (struct ec_response_get_version *)msg->data;
165 	/* Strings should be null-terminated, but let's be sure. */
166 	r_ver->version_string_ro[sizeof(r_ver->version_string_ro) - 1] = '\0';
167 	r_ver->version_string_rw[sizeof(r_ver->version_string_rw) - 1] = '\0';
168 	count += scnprintf(buf + count, PAGE_SIZE - count,
169 			   "RO version:    %s\n", r_ver->version_string_ro);
170 	count += scnprintf(buf + count, PAGE_SIZE - count,
171 			   "RW version:    %s\n", r_ver->version_string_rw);
172 	count += scnprintf(buf + count, PAGE_SIZE - count,
173 			   "Firmware copy: %s\n",
174 			   (r_ver->current_image < ARRAY_SIZE(image_names) ?
175 			    image_names[r_ver->current_image] : "?"));
176 
177 	/* Get build info. */
178 	msg->command = EC_CMD_GET_BUILD_INFO + ec->cmd_offset;
179 	msg->insize = EC_HOST_PARAM_SIZE;
180 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
181 	if (ret < 0)
182 		count += scnprintf(buf + count, PAGE_SIZE - count,
183 				   "Build info:    XFER ERROR %d\n", ret);
184 	else if (msg->result != EC_RES_SUCCESS)
185 		count += scnprintf(buf + count, PAGE_SIZE - count,
186 				   "Build info:    EC error %d\n", msg->result);
187 	else {
188 		msg->data[EC_HOST_PARAM_SIZE - 1] = '\0';
189 		count += scnprintf(buf + count, PAGE_SIZE - count,
190 				   "Build info:    %s\n", msg->data);
191 	}
192 
193 	/* Get chip info. */
194 	msg->command = EC_CMD_GET_CHIP_INFO + ec->cmd_offset;
195 	msg->insize = sizeof(*r_chip);
196 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
197 	if (ret < 0)
198 		count += scnprintf(buf + count, PAGE_SIZE - count,
199 				   "Chip info:     XFER ERROR %d\n", ret);
200 	else if (msg->result != EC_RES_SUCCESS)
201 		count += scnprintf(buf + count, PAGE_SIZE - count,
202 				   "Chip info:     EC error %d\n", msg->result);
203 	else {
204 		r_chip = (struct ec_response_get_chip_info *)msg->data;
205 
206 		r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
207 		r_chip->name[sizeof(r_chip->name) - 1] = '\0';
208 		r_chip->revision[sizeof(r_chip->revision) - 1] = '\0';
209 		count += scnprintf(buf + count, PAGE_SIZE - count,
210 				   "Chip vendor:   %s\n", r_chip->vendor);
211 		count += scnprintf(buf + count, PAGE_SIZE - count,
212 				   "Chip name:     %s\n", r_chip->name);
213 		count += scnprintf(buf + count, PAGE_SIZE - count,
214 				   "Chip revision: %s\n", r_chip->revision);
215 	}
216 
217 	/* Get board version */
218 	msg->command = EC_CMD_GET_BOARD_VERSION + ec->cmd_offset;
219 	msg->insize = sizeof(*r_board);
220 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
221 	if (ret < 0)
222 		count += scnprintf(buf + count, PAGE_SIZE - count,
223 				   "Board version: XFER ERROR %d\n", ret);
224 	else if (msg->result != EC_RES_SUCCESS)
225 		count += scnprintf(buf + count, PAGE_SIZE - count,
226 				   "Board version: EC error %d\n", msg->result);
227 	else {
228 		r_board = (struct ec_response_board_version *)msg->data;
229 
230 		count += scnprintf(buf + count, PAGE_SIZE - count,
231 				   "Board version: %d\n",
232 				   r_board->board_version);
233 	}
234 
235 exit:
236 	kfree(msg);
237 	return count;
238 }
239 
240 static ssize_t show_ec_flashinfo(struct device *dev,
241 				 struct device_attribute *attr, char *buf)
242 {
243 	struct ec_response_flash_info *resp;
244 	struct cros_ec_command *msg;
245 	int ret;
246 	struct cros_ec_dev *ec = container_of(dev,
247 					      struct cros_ec_dev, class_dev);
248 
249 	msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
250 	if (!msg)
251 		return -ENOMEM;
252 
253 	/* The flash info shouldn't ever change, but ask each time anyway. */
254 	msg->version = 0;
255 	msg->command = EC_CMD_FLASH_INFO + ec->cmd_offset;
256 	msg->insize = sizeof(*resp);
257 	msg->outsize = 0;
258 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
259 	if (ret < 0)
260 		goto exit;
261 	if (msg->result != EC_RES_SUCCESS) {
262 		ret = scnprintf(buf, PAGE_SIZE,
263 				"ERROR: EC returned %d\n", msg->result);
264 		goto exit;
265 	}
266 
267 	resp = (struct ec_response_flash_info *)msg->data;
268 
269 	ret = scnprintf(buf, PAGE_SIZE,
270 			"FlashSize %d\nWriteSize %d\n"
271 			"EraseSize %d\nProtectSize %d\n",
272 			resp->flash_size, resp->write_block_size,
273 			resp->erase_block_size, resp->protect_block_size);
274 exit:
275 	kfree(msg);
276 	return ret;
277 }
278 
279 /* Module initialization */
280 
281 static DEVICE_ATTR(reboot, S_IWUSR | S_IRUGO, show_ec_reboot, store_ec_reboot);
282 static DEVICE_ATTR(version, S_IRUGO, show_ec_version, NULL);
283 static DEVICE_ATTR(flashinfo, S_IRUGO, show_ec_flashinfo, NULL);
284 
285 static struct attribute *__ec_attrs[] = {
286 	&dev_attr_reboot.attr,
287 	&dev_attr_version.attr,
288 	&dev_attr_flashinfo.attr,
289 	NULL,
290 };
291 
292 struct attribute_group cros_ec_attr_group = {
293 	.attrs = __ec_attrs,
294 };
295 EXPORT_SYMBOL(cros_ec_attr_group);
296 
297 MODULE_LICENSE("GPL");
298 MODULE_DESCRIPTION("ChromeOS EC control driver");
299