1 // SPDX-License-Identifier: GPL-2.0+
2 // Expose the ChromeOS EC through sysfs
3 //
4 // Copyright (C) 2014 Google, Inc.
5 
6 #include <linux/ctype.h>
7 #include <linux/delay.h>
8 #include <linux/device.h>
9 #include <linux/fs.h>
10 #include <linux/kobject.h>
11 #include <linux/mfd/cros_ec.h>
12 #include <linux/mfd/cros_ec_commands.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/printk.h>
16 #include <linux/slab.h>
17 #include <linux/stat.h>
18 #include <linux/types.h>
19 #include <linux/uaccess.h>
20 
21 #define DRV_NAME "cros-ec-sysfs"
22 
23 /* Accessor functions */
24 
25 static ssize_t reboot_show(struct device *dev,
26 			   struct device_attribute *attr, char *buf)
27 {
28 	int count = 0;
29 
30 	count += scnprintf(buf + count, PAGE_SIZE - count,
31 			   "ro|rw|cancel|cold|disable-jump|hibernate");
32 	count += scnprintf(buf + count, PAGE_SIZE - count,
33 			   " [at-shutdown]\n");
34 	return count;
35 }
36 
37 static ssize_t reboot_store(struct device *dev,
38 			    struct device_attribute *attr,
39 			    const char *buf, size_t count)
40 {
41 	static const struct {
42 		const char * const str;
43 		uint8_t cmd;
44 		uint8_t flags;
45 	} words[] = {
46 		{"cancel",       EC_REBOOT_CANCEL, 0},
47 		{"ro",           EC_REBOOT_JUMP_RO, 0},
48 		{"rw",           EC_REBOOT_JUMP_RW, 0},
49 		{"cold",         EC_REBOOT_COLD, 0},
50 		{"disable-jump", EC_REBOOT_DISABLE_JUMP, 0},
51 		{"hibernate",    EC_REBOOT_HIBERNATE, 0},
52 		{"at-shutdown",  -1, EC_REBOOT_FLAG_ON_AP_SHUTDOWN},
53 	};
54 	struct cros_ec_command *msg;
55 	struct ec_params_reboot_ec *param;
56 	int got_cmd = 0, offset = 0;
57 	int i;
58 	int ret;
59 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
60 
61 	msg = kmalloc(sizeof(*msg) + sizeof(*param), GFP_KERNEL);
62 	if (!msg)
63 		return -ENOMEM;
64 
65 	param = (struct ec_params_reboot_ec *)msg->data;
66 
67 	param->flags = 0;
68 	while (1) {
69 		/* Find word to start scanning */
70 		while (buf[offset] && isspace(buf[offset]))
71 			offset++;
72 		if (!buf[offset])
73 			break;
74 
75 		for (i = 0; i < ARRAY_SIZE(words); i++) {
76 			if (!strncasecmp(words[i].str, buf+offset,
77 					 strlen(words[i].str))) {
78 				if (words[i].flags) {
79 					param->flags |= words[i].flags;
80 				} else {
81 					param->cmd = words[i].cmd;
82 					got_cmd = 1;
83 				}
84 				break;
85 			}
86 		}
87 
88 		/* On to the next word, if any */
89 		while (buf[offset] && !isspace(buf[offset]))
90 			offset++;
91 	}
92 
93 	if (!got_cmd) {
94 		count = -EINVAL;
95 		goto exit;
96 	}
97 
98 	msg->version = 0;
99 	msg->command = EC_CMD_REBOOT_EC + ec->cmd_offset;
100 	msg->outsize = sizeof(*param);
101 	msg->insize = 0;
102 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
103 	if (ret < 0)
104 		count = ret;
105 exit:
106 	kfree(msg);
107 	return count;
108 }
109 
110 static ssize_t version_show(struct device *dev,
111 			    struct device_attribute *attr, char *buf)
112 {
113 	static const char * const image_names[] = {"unknown", "RO", "RW"};
114 	struct ec_response_get_version *r_ver;
115 	struct ec_response_get_chip_info *r_chip;
116 	struct ec_response_board_version *r_board;
117 	struct cros_ec_command *msg;
118 	int ret;
119 	int count = 0;
120 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
121 
122 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
123 	if (!msg)
124 		return -ENOMEM;
125 
126 	/* Get versions. RW may change. */
127 	msg->version = 0;
128 	msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
129 	msg->insize = sizeof(*r_ver);
130 	msg->outsize = 0;
131 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
132 	if (ret < 0) {
133 		count = ret;
134 		goto exit;
135 	}
136 	r_ver = (struct ec_response_get_version *)msg->data;
137 	/* Strings should be null-terminated, but let's be sure. */
138 	r_ver->version_string_ro[sizeof(r_ver->version_string_ro) - 1] = '\0';
139 	r_ver->version_string_rw[sizeof(r_ver->version_string_rw) - 1] = '\0';
140 	count += scnprintf(buf + count, PAGE_SIZE - count,
141 			   "RO version:    %s\n", r_ver->version_string_ro);
142 	count += scnprintf(buf + count, PAGE_SIZE - count,
143 			   "RW version:    %s\n", r_ver->version_string_rw);
144 	count += scnprintf(buf + count, PAGE_SIZE - count,
145 			   "Firmware copy: %s\n",
146 			   (r_ver->current_image < ARRAY_SIZE(image_names) ?
147 			    image_names[r_ver->current_image] : "?"));
148 
149 	/* Get build info. */
150 	msg->command = EC_CMD_GET_BUILD_INFO + ec->cmd_offset;
151 	msg->insize = EC_HOST_PARAM_SIZE;
152 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
153 	if (ret < 0)
154 		count += scnprintf(buf + count, PAGE_SIZE - count,
155 				   "Build info:    XFER ERROR %d\n", ret);
156 	else if (msg->result != EC_RES_SUCCESS)
157 		count += scnprintf(buf + count, PAGE_SIZE - count,
158 				   "Build info:    EC error %d\n", msg->result);
159 	else {
160 		msg->data[EC_HOST_PARAM_SIZE - 1] = '\0';
161 		count += scnprintf(buf + count, PAGE_SIZE - count,
162 				   "Build info:    %s\n", msg->data);
163 	}
164 
165 	/* Get chip info. */
166 	msg->command = EC_CMD_GET_CHIP_INFO + ec->cmd_offset;
167 	msg->insize = sizeof(*r_chip);
168 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
169 	if (ret < 0)
170 		count += scnprintf(buf + count, PAGE_SIZE - count,
171 				   "Chip info:     XFER ERROR %d\n", ret);
172 	else if (msg->result != EC_RES_SUCCESS)
173 		count += scnprintf(buf + count, PAGE_SIZE - count,
174 				   "Chip info:     EC error %d\n", msg->result);
175 	else {
176 		r_chip = (struct ec_response_get_chip_info *)msg->data;
177 
178 		r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
179 		r_chip->name[sizeof(r_chip->name) - 1] = '\0';
180 		r_chip->revision[sizeof(r_chip->revision) - 1] = '\0';
181 		count += scnprintf(buf + count, PAGE_SIZE - count,
182 				   "Chip vendor:   %s\n", r_chip->vendor);
183 		count += scnprintf(buf + count, PAGE_SIZE - count,
184 				   "Chip name:     %s\n", r_chip->name);
185 		count += scnprintf(buf + count, PAGE_SIZE - count,
186 				   "Chip revision: %s\n", r_chip->revision);
187 	}
188 
189 	/* Get board version */
190 	msg->command = EC_CMD_GET_BOARD_VERSION + ec->cmd_offset;
191 	msg->insize = sizeof(*r_board);
192 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
193 	if (ret < 0)
194 		count += scnprintf(buf + count, PAGE_SIZE - count,
195 				   "Board version: XFER ERROR %d\n", ret);
196 	else if (msg->result != EC_RES_SUCCESS)
197 		count += scnprintf(buf + count, PAGE_SIZE - count,
198 				   "Board version: EC error %d\n", msg->result);
199 	else {
200 		r_board = (struct ec_response_board_version *)msg->data;
201 
202 		count += scnprintf(buf + count, PAGE_SIZE - count,
203 				   "Board version: %d\n",
204 				   r_board->board_version);
205 	}
206 
207 exit:
208 	kfree(msg);
209 	return count;
210 }
211 
212 static ssize_t flashinfo_show(struct device *dev,
213 			      struct device_attribute *attr, char *buf)
214 {
215 	struct ec_response_flash_info *resp;
216 	struct cros_ec_command *msg;
217 	int ret;
218 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
219 
220 	msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
221 	if (!msg)
222 		return -ENOMEM;
223 
224 	/* The flash info shouldn't ever change, but ask each time anyway. */
225 	msg->version = 0;
226 	msg->command = EC_CMD_FLASH_INFO + ec->cmd_offset;
227 	msg->insize = sizeof(*resp);
228 	msg->outsize = 0;
229 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
230 	if (ret < 0)
231 		goto exit;
232 
233 	resp = (struct ec_response_flash_info *)msg->data;
234 
235 	ret = scnprintf(buf, PAGE_SIZE,
236 			"FlashSize %d\nWriteSize %d\n"
237 			"EraseSize %d\nProtectSize %d\n",
238 			resp->flash_size, resp->write_block_size,
239 			resp->erase_block_size, resp->protect_block_size);
240 exit:
241 	kfree(msg);
242 	return ret;
243 }
244 
245 /* Keyboard wake angle control */
246 static ssize_t kb_wake_angle_show(struct device *dev,
247 				  struct device_attribute *attr, char *buf)
248 {
249 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
250 	struct ec_response_motion_sense *resp;
251 	struct ec_params_motion_sense *param;
252 	struct cros_ec_command *msg;
253 	int ret;
254 
255 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
256 	if (!msg)
257 		return -ENOMEM;
258 
259 	param = (struct ec_params_motion_sense *)msg->data;
260 	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
261 	msg->version = 2;
262 	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
263 	param->kb_wake_angle.data = EC_MOTION_SENSE_NO_VALUE;
264 	msg->outsize = sizeof(*param);
265 	msg->insize = sizeof(*resp);
266 
267 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
268 	if (ret < 0)
269 		goto exit;
270 
271 	resp = (struct ec_response_motion_sense *)msg->data;
272 	ret = scnprintf(buf, PAGE_SIZE, "%d\n", resp->kb_wake_angle.ret);
273 exit:
274 	kfree(msg);
275 	return ret;
276 }
277 
278 static ssize_t kb_wake_angle_store(struct device *dev,
279 				   struct device_attribute *attr,
280 				   const char *buf, size_t count)
281 {
282 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
283 	struct ec_params_motion_sense *param;
284 	struct cros_ec_command *msg;
285 	u16 angle;
286 	int ret;
287 
288 	ret = kstrtou16(buf, 0, &angle);
289 	if (ret)
290 		return ret;
291 
292 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
293 	if (!msg)
294 		return -ENOMEM;
295 
296 	param = (struct ec_params_motion_sense *)msg->data;
297 	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
298 	msg->version = 2;
299 	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
300 	param->kb_wake_angle.data = angle;
301 	msg->outsize = sizeof(*param);
302 	msg->insize = sizeof(struct ec_response_motion_sense);
303 
304 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
305 	kfree(msg);
306 	if (ret < 0)
307 		return ret;
308 	return count;
309 }
310 
311 /* Module initialization */
312 
313 static DEVICE_ATTR_RW(reboot);
314 static DEVICE_ATTR_RO(version);
315 static DEVICE_ATTR_RO(flashinfo);
316 static DEVICE_ATTR_RW(kb_wake_angle);
317 
318 static struct attribute *__ec_attrs[] = {
319 	&dev_attr_kb_wake_angle.attr,
320 	&dev_attr_reboot.attr,
321 	&dev_attr_version.attr,
322 	&dev_attr_flashinfo.attr,
323 	NULL,
324 };
325 
326 static umode_t cros_ec_ctrl_visible(struct kobject *kobj,
327 				    struct attribute *a, int n)
328 {
329 	struct device *dev = container_of(kobj, struct device, kobj);
330 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
331 
332 	if (a == &dev_attr_kb_wake_angle.attr && !ec->has_kb_wake_angle)
333 		return 0;
334 
335 	return a->mode;
336 }
337 
338 static struct attribute_group cros_ec_attr_group = {
339 	.attrs = __ec_attrs,
340 	.is_visible = cros_ec_ctrl_visible,
341 };
342 
343 static int cros_ec_sysfs_probe(struct platform_device *pd)
344 {
345 	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
346 	struct device *dev = &pd->dev;
347 	int ret;
348 
349 	ret = sysfs_create_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
350 	if (ret < 0)
351 		dev_err(dev, "failed to create attributes. err=%d\n", ret);
352 
353 	return ret;
354 }
355 
356 static int cros_ec_sysfs_remove(struct platform_device *pd)
357 {
358 	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
359 
360 	sysfs_remove_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
361 
362 	return 0;
363 }
364 
365 static struct platform_driver cros_ec_sysfs_driver = {
366 	.driver = {
367 		.name = DRV_NAME,
368 	},
369 	.probe = cros_ec_sysfs_probe,
370 	.remove = cros_ec_sysfs_remove,
371 };
372 
373 module_platform_driver(cros_ec_sysfs_driver);
374 
375 MODULE_LICENSE("GPL");
376 MODULE_DESCRIPTION("Expose the ChromeOS EC through sysfs");
377 MODULE_ALIAS("platform:" DRV_NAME);
378