xref: /linux/drivers/platform/chrome/cros_ec_sysfs.c (revision 69bfec7548f4c1595bac0e3ddfc0458a5af31f4c)
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/module.h>
12 #include <linux/platform_data/cros_ec_commands.h>
13 #include <linux/platform_data/cros_ec_proto.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 += sysfs_emit_at(buf, count,
31 			       "ro|rw|cancel|cold|disable-jump|hibernate|cold-ap-off");
32 	count += sysfs_emit_at(buf, count, " [at-shutdown]\n");
33 	return count;
34 }
35 
36 static ssize_t reboot_store(struct device *dev,
37 			    struct device_attribute *attr,
38 			    const char *buf, size_t count)
39 {
40 	static const struct {
41 		const char * const str;
42 		uint8_t cmd;
43 		uint8_t flags;
44 	} words[] = {
45 		{"cancel",       EC_REBOOT_CANCEL, 0},
46 		{"ro",           EC_REBOOT_JUMP_RO, 0},
47 		{"rw",           EC_REBOOT_JUMP_RW, 0},
48 		{"cold-ap-off",  EC_REBOOT_COLD_AP_OFF, 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 += sysfs_emit_at(buf, count, "RO version:    %s\n", r_ver->version_string_ro);
141 	count += sysfs_emit_at(buf, count, "RW version:    %s\n", r_ver->version_string_rw);
142 	count += sysfs_emit_at(buf, count, "Firmware copy: %s\n",
143 			   (r_ver->current_image < ARRAY_SIZE(image_names) ?
144 			    image_names[r_ver->current_image] : "?"));
145 
146 	/* Get build info. */
147 	msg->command = EC_CMD_GET_BUILD_INFO + ec->cmd_offset;
148 	msg->insize = EC_HOST_PARAM_SIZE;
149 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
150 	if (ret < 0) {
151 		count += sysfs_emit_at(buf, count,
152 				   "Build info:    XFER / EC ERROR %d / %d\n",
153 				   ret, msg->result);
154 	} else {
155 		msg->data[EC_HOST_PARAM_SIZE - 1] = '\0';
156 		count += sysfs_emit_at(buf, count, "Build info:    %s\n", msg->data);
157 	}
158 
159 	/* Get chip info. */
160 	msg->command = EC_CMD_GET_CHIP_INFO + ec->cmd_offset;
161 	msg->insize = sizeof(*r_chip);
162 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
163 	if (ret < 0) {
164 		count += sysfs_emit_at(buf, count,
165 				   "Chip info:     XFER / EC ERROR %d / %d\n",
166 				   ret, msg->result);
167 	} else {
168 		r_chip = (struct ec_response_get_chip_info *)msg->data;
169 
170 		r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
171 		r_chip->name[sizeof(r_chip->name) - 1] = '\0';
172 		r_chip->revision[sizeof(r_chip->revision) - 1] = '\0';
173 		count += sysfs_emit_at(buf, count, "Chip vendor:   %s\n", r_chip->vendor);
174 		count += sysfs_emit_at(buf, count, "Chip name:     %s\n", r_chip->name);
175 		count += sysfs_emit_at(buf, count, "Chip revision: %s\n", r_chip->revision);
176 	}
177 
178 	/* Get board version */
179 	msg->command = EC_CMD_GET_BOARD_VERSION + ec->cmd_offset;
180 	msg->insize = sizeof(*r_board);
181 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
182 	if (ret < 0) {
183 		count += sysfs_emit_at(buf, count,
184 				   "Board version: XFER / EC ERROR %d / %d\n",
185 				   ret, msg->result);
186 	} else {
187 		r_board = (struct ec_response_board_version *)msg->data;
188 
189 		count += sysfs_emit_at(buf, count,
190 				   "Board version: %d\n",
191 				   r_board->board_version);
192 	}
193 
194 exit:
195 	kfree(msg);
196 	return count;
197 }
198 
199 static ssize_t flashinfo_show(struct device *dev,
200 			      struct device_attribute *attr, char *buf)
201 {
202 	struct ec_response_flash_info *resp;
203 	struct cros_ec_command *msg;
204 	int ret;
205 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
206 
207 	msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
208 	if (!msg)
209 		return -ENOMEM;
210 
211 	/* The flash info shouldn't ever change, but ask each time anyway. */
212 	msg->version = 0;
213 	msg->command = EC_CMD_FLASH_INFO + ec->cmd_offset;
214 	msg->insize = sizeof(*resp);
215 	msg->outsize = 0;
216 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
217 	if (ret < 0)
218 		goto exit;
219 
220 	resp = (struct ec_response_flash_info *)msg->data;
221 
222 	ret = sysfs_emit(buf,
223 			"FlashSize %d\nWriteSize %d\n"
224 			"EraseSize %d\nProtectSize %d\n",
225 			resp->flash_size, resp->write_block_size,
226 			resp->erase_block_size, resp->protect_block_size);
227 exit:
228 	kfree(msg);
229 	return ret;
230 }
231 
232 /* Keyboard wake angle control */
233 static ssize_t kb_wake_angle_show(struct device *dev,
234 				  struct device_attribute *attr, char *buf)
235 {
236 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
237 	struct ec_response_motion_sense *resp;
238 	struct ec_params_motion_sense *param;
239 	struct cros_ec_command *msg;
240 	int ret;
241 
242 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
243 	if (!msg)
244 		return -ENOMEM;
245 
246 	param = (struct ec_params_motion_sense *)msg->data;
247 	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
248 	msg->version = 2;
249 	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
250 	param->kb_wake_angle.data = EC_MOTION_SENSE_NO_VALUE;
251 	msg->outsize = sizeof(*param);
252 	msg->insize = sizeof(*resp);
253 
254 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
255 	if (ret < 0)
256 		goto exit;
257 
258 	resp = (struct ec_response_motion_sense *)msg->data;
259 	ret = sysfs_emit(buf, "%d\n", resp->kb_wake_angle.ret);
260 exit:
261 	kfree(msg);
262 	return ret;
263 }
264 
265 static ssize_t kb_wake_angle_store(struct device *dev,
266 				   struct device_attribute *attr,
267 				   const char *buf, size_t count)
268 {
269 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
270 	struct ec_params_motion_sense *param;
271 	struct cros_ec_command *msg;
272 	u16 angle;
273 	int ret;
274 
275 	ret = kstrtou16(buf, 0, &angle);
276 	if (ret)
277 		return ret;
278 
279 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
280 	if (!msg)
281 		return -ENOMEM;
282 
283 	param = (struct ec_params_motion_sense *)msg->data;
284 	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
285 	msg->version = 2;
286 	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
287 	param->kb_wake_angle.data = angle;
288 	msg->outsize = sizeof(*param);
289 	msg->insize = sizeof(struct ec_response_motion_sense);
290 
291 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
292 	kfree(msg);
293 	if (ret < 0)
294 		return ret;
295 	return count;
296 }
297 
298 /* Module initialization */
299 
300 static DEVICE_ATTR_RW(reboot);
301 static DEVICE_ATTR_RO(version);
302 static DEVICE_ATTR_RO(flashinfo);
303 static DEVICE_ATTR_RW(kb_wake_angle);
304 
305 static struct attribute *__ec_attrs[] = {
306 	&dev_attr_kb_wake_angle.attr,
307 	&dev_attr_reboot.attr,
308 	&dev_attr_version.attr,
309 	&dev_attr_flashinfo.attr,
310 	NULL,
311 };
312 
313 static umode_t cros_ec_ctrl_visible(struct kobject *kobj,
314 				    struct attribute *a, int n)
315 {
316 	struct device *dev = kobj_to_dev(kobj);
317 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
318 
319 	if (a == &dev_attr_kb_wake_angle.attr && !ec->has_kb_wake_angle)
320 		return 0;
321 
322 	return a->mode;
323 }
324 
325 static const struct attribute_group cros_ec_attr_group = {
326 	.attrs = __ec_attrs,
327 	.is_visible = cros_ec_ctrl_visible,
328 };
329 
330 static int cros_ec_sysfs_probe(struct platform_device *pd)
331 {
332 	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
333 	struct device *dev = &pd->dev;
334 	int ret;
335 
336 	ret = sysfs_create_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
337 	if (ret < 0)
338 		dev_err(dev, "failed to create attributes. err=%d\n", ret);
339 
340 	return ret;
341 }
342 
343 static int cros_ec_sysfs_remove(struct platform_device *pd)
344 {
345 	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
346 
347 	sysfs_remove_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
348 
349 	return 0;
350 }
351 
352 static struct platform_driver cros_ec_sysfs_driver = {
353 	.driver = {
354 		.name = DRV_NAME,
355 	},
356 	.probe = cros_ec_sysfs_probe,
357 	.remove = cros_ec_sysfs_remove,
358 };
359 
360 module_platform_driver(cros_ec_sysfs_driver);
361 
362 MODULE_LICENSE("GPL");
363 MODULE_DESCRIPTION("Expose the ChromeOS EC through sysfs");
364 MODULE_ALIAS("platform:" DRV_NAME);
365