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 #include "cros_ec_dev.h"
38 
39 /* Accessor functions */
40 
41 static ssize_t show_ec_reboot(struct device *dev,
42 			      struct device_attribute *attr, char *buf)
43 {
44 	int count = 0;
45 
46 	count += scnprintf(buf + count, PAGE_SIZE - count,
47 			   "ro|rw|cancel|cold|disable-jump|hibernate");
48 	count += scnprintf(buf + count, PAGE_SIZE - count,
49 			   " [at-shutdown]\n");
50 	return count;
51 }
52 
53 static ssize_t store_ec_reboot(struct device *dev,
54 			       struct device_attribute *attr,
55 			       const char *buf, size_t count)
56 {
57 	static const struct {
58 		const char * const str;
59 		uint8_t cmd;
60 		uint8_t flags;
61 	} words[] = {
62 		{"cancel",       EC_REBOOT_CANCEL, 0},
63 		{"ro",           EC_REBOOT_JUMP_RO, 0},
64 		{"rw",           EC_REBOOT_JUMP_RW, 0},
65 		{"cold",         EC_REBOOT_COLD, 0},
66 		{"disable-jump", EC_REBOOT_DISABLE_JUMP, 0},
67 		{"hibernate",    EC_REBOOT_HIBERNATE, 0},
68 		{"at-shutdown",  -1, EC_REBOOT_FLAG_ON_AP_SHUTDOWN},
69 	};
70 	struct cros_ec_command *msg;
71 	struct ec_params_reboot_ec *param;
72 	int got_cmd = 0, offset = 0;
73 	int i;
74 	int ret;
75 	struct cros_ec_dev *ec = container_of(dev,
76 					      struct cros_ec_dev, class_dev);
77 
78 	msg = kmalloc(sizeof(*msg) + sizeof(*param), GFP_KERNEL);
79 	if (!msg)
80 		return -ENOMEM;
81 
82 	param = (struct ec_params_reboot_ec *)msg->data;
83 
84 	param->flags = 0;
85 	while (1) {
86 		/* Find word to start scanning */
87 		while (buf[offset] && isspace(buf[offset]))
88 			offset++;
89 		if (!buf[offset])
90 			break;
91 
92 		for (i = 0; i < ARRAY_SIZE(words); i++) {
93 			if (!strncasecmp(words[i].str, buf+offset,
94 					 strlen(words[i].str))) {
95 				if (words[i].flags) {
96 					param->flags |= words[i].flags;
97 				} else {
98 					param->cmd = words[i].cmd;
99 					got_cmd = 1;
100 				}
101 				break;
102 			}
103 		}
104 
105 		/* On to the next word, if any */
106 		while (buf[offset] && !isspace(buf[offset]))
107 			offset++;
108 	}
109 
110 	if (!got_cmd) {
111 		count = -EINVAL;
112 		goto exit;
113 	}
114 
115 	msg->version = 0;
116 	msg->command = EC_CMD_REBOOT_EC + ec->cmd_offset;
117 	msg->outsize = sizeof(*param);
118 	msg->insize = 0;
119 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
120 	if (ret < 0) {
121 		count = ret;
122 		goto exit;
123 	}
124 	if (msg->result != EC_RES_SUCCESS) {
125 		dev_dbg(ec->dev, "EC result %d\n", msg->result);
126 		count = -EINVAL;
127 	}
128 exit:
129 	kfree(msg);
130 	return count;
131 }
132 
133 static ssize_t show_ec_version(struct device *dev,
134 			       struct device_attribute *attr, char *buf)
135 {
136 	static const char * const image_names[] = {"unknown", "RO", "RW"};
137 	struct ec_response_get_version *r_ver;
138 	struct ec_response_get_chip_info *r_chip;
139 	struct ec_response_board_version *r_board;
140 	struct cros_ec_command *msg;
141 	int ret;
142 	int count = 0;
143 	struct cros_ec_dev *ec = container_of(dev,
144 					      struct cros_ec_dev, class_dev);
145 
146 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
147 	if (!msg)
148 		return -ENOMEM;
149 
150 	/* Get versions. RW may change. */
151 	msg->version = 0;
152 	msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
153 	msg->insize = sizeof(*r_ver);
154 	msg->outsize = 0;
155 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
156 	if (ret < 0) {
157 		count = ret;
158 		goto exit;
159 	}
160 	if (msg->result != EC_RES_SUCCESS) {
161 		count = scnprintf(buf, PAGE_SIZE,
162 				  "ERROR: EC returned %d\n", msg->result);
163 		goto exit;
164 	}
165 
166 	r_ver = (struct ec_response_get_version *)msg->data;
167 	/* Strings should be null-terminated, but let's be sure. */
168 	r_ver->version_string_ro[sizeof(r_ver->version_string_ro) - 1] = '\0';
169 	r_ver->version_string_rw[sizeof(r_ver->version_string_rw) - 1] = '\0';
170 	count += scnprintf(buf + count, PAGE_SIZE - count,
171 			   "RO version:    %s\n", r_ver->version_string_ro);
172 	count += scnprintf(buf + count, PAGE_SIZE - count,
173 			   "RW version:    %s\n", r_ver->version_string_rw);
174 	count += scnprintf(buf + count, PAGE_SIZE - count,
175 			   "Firmware copy: %s\n",
176 			   (r_ver->current_image < ARRAY_SIZE(image_names) ?
177 			    image_names[r_ver->current_image] : "?"));
178 
179 	/* Get build info. */
180 	msg->command = EC_CMD_GET_BUILD_INFO + ec->cmd_offset;
181 	msg->insize = EC_HOST_PARAM_SIZE;
182 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
183 	if (ret < 0)
184 		count += scnprintf(buf + count, PAGE_SIZE - count,
185 				   "Build info:    XFER ERROR %d\n", ret);
186 	else if (msg->result != EC_RES_SUCCESS)
187 		count += scnprintf(buf + count, PAGE_SIZE - count,
188 				   "Build info:    EC error %d\n", msg->result);
189 	else {
190 		msg->data[sizeof(msg->data) - 1] = '\0';
191 		count += scnprintf(buf + count, PAGE_SIZE - count,
192 				   "Build info:    %s\n", msg->data);
193 	}
194 
195 	/* Get chip info. */
196 	msg->command = EC_CMD_GET_CHIP_INFO + ec->cmd_offset;
197 	msg->insize = sizeof(*r_chip);
198 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
199 	if (ret < 0)
200 		count += scnprintf(buf + count, PAGE_SIZE - count,
201 				   "Chip info:     XFER ERROR %d\n", ret);
202 	else if (msg->result != EC_RES_SUCCESS)
203 		count += scnprintf(buf + count, PAGE_SIZE - count,
204 				   "Chip info:     EC error %d\n", msg->result);
205 	else {
206 		r_chip = (struct ec_response_get_chip_info *)msg->data;
207 
208 		r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
209 		r_chip->name[sizeof(r_chip->name) - 1] = '\0';
210 		r_chip->revision[sizeof(r_chip->revision) - 1] = '\0';
211 		count += scnprintf(buf + count, PAGE_SIZE - count,
212 				   "Chip vendor:   %s\n", r_chip->vendor);
213 		count += scnprintf(buf + count, PAGE_SIZE - count,
214 				   "Chip name:     %s\n", r_chip->name);
215 		count += scnprintf(buf + count, PAGE_SIZE - count,
216 				   "Chip revision: %s\n", r_chip->revision);
217 	}
218 
219 	/* Get board version */
220 	msg->command = EC_CMD_GET_BOARD_VERSION + ec->cmd_offset;
221 	msg->insize = sizeof(*r_board);
222 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
223 	if (ret < 0)
224 		count += scnprintf(buf + count, PAGE_SIZE - count,
225 				   "Board version: XFER ERROR %d\n", ret);
226 	else if (msg->result != EC_RES_SUCCESS)
227 		count += scnprintf(buf + count, PAGE_SIZE - count,
228 				   "Board version: EC error %d\n", msg->result);
229 	else {
230 		r_board = (struct ec_response_board_version *)msg->data;
231 
232 		count += scnprintf(buf + count, PAGE_SIZE - count,
233 				   "Board version: %d\n",
234 				   r_board->board_version);
235 	}
236 
237 exit:
238 	kfree(msg);
239 	return count;
240 }
241 
242 static ssize_t show_ec_flashinfo(struct device *dev,
243 				 struct device_attribute *attr, char *buf)
244 {
245 	struct ec_response_flash_info *resp;
246 	struct cros_ec_command *msg;
247 	int ret;
248 	struct cros_ec_dev *ec = container_of(dev,
249 					      struct cros_ec_dev, class_dev);
250 
251 	msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
252 	if (!msg)
253 		return -ENOMEM;
254 
255 	/* The flash info shouldn't ever change, but ask each time anyway. */
256 	msg->version = 0;
257 	msg->command = EC_CMD_FLASH_INFO + ec->cmd_offset;
258 	msg->insize = sizeof(*resp);
259 	msg->outsize = 0;
260 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
261 	if (ret < 0)
262 		goto exit;
263 	if (msg->result != EC_RES_SUCCESS) {
264 		ret = scnprintf(buf, PAGE_SIZE,
265 				"ERROR: EC returned %d\n", msg->result);
266 		goto exit;
267 	}
268 
269 	resp = (struct ec_response_flash_info *)msg->data;
270 
271 	ret = scnprintf(buf, PAGE_SIZE,
272 			"FlashSize %d\nWriteSize %d\n"
273 			"EraseSize %d\nProtectSize %d\n",
274 			resp->flash_size, resp->write_block_size,
275 			resp->erase_block_size, resp->protect_block_size);
276 exit:
277 	kfree(msg);
278 	return ret;
279 }
280 
281 /* Module initialization */
282 
283 static DEVICE_ATTR(reboot, S_IWUSR | S_IRUGO, show_ec_reboot, store_ec_reboot);
284 static DEVICE_ATTR(version, S_IRUGO, show_ec_version, NULL);
285 static DEVICE_ATTR(flashinfo, S_IRUGO, show_ec_flashinfo, NULL);
286 
287 static struct attribute *__ec_attrs[] = {
288 	&dev_attr_reboot.attr,
289 	&dev_attr_version.attr,
290 	&dev_attr_flashinfo.attr,
291 	NULL,
292 };
293 
294 struct attribute_group cros_ec_attr_group = {
295 	.attrs = __ec_attrs,
296 };
297 
298