xref: /linux/drivers/platform/chrome/cros_ec_sysfs.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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/mod_devicetable.h>
12 #include <linux/module.h>
13 #include <linux/platform_data/cros_ec_commands.h>
14 #include <linux/platform_data/cros_ec_proto.h>
15 #include <linux/platform_device.h>
16 #include <linux/printk.h>
17 #include <linux/slab.h>
18 #include <linux/stat.h>
19 #include <linux/types.h>
20 #include <linux/uaccess.h>
21 
22 #define DRV_NAME "cros-ec-sysfs"
23 
24 /* Accessor functions */
25 
26 static ssize_t reboot_show(struct device *dev,
27 			   struct device_attribute *attr, char *buf)
28 {
29 	int count = 0;
30 
31 	count += sysfs_emit_at(buf, count,
32 			       "ro|rw|cancel|cold|disable-jump|hibernate|cold-ap-off");
33 	count += sysfs_emit_at(buf, count, " [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-ap-off",  EC_REBOOT_COLD_AP_OFF, 0},
50 		{"cold",         EC_REBOOT_COLD, 0},
51 		{"disable-jump", EC_REBOOT_DISABLE_JUMP, 0},
52 		{"hibernate",    EC_REBOOT_HIBERNATE, 0},
53 		{"at-shutdown",  -1, EC_REBOOT_FLAG_ON_AP_SHUTDOWN},
54 	};
55 	struct cros_ec_command *msg;
56 	struct ec_params_reboot_ec *param;
57 	int got_cmd = 0, offset = 0;
58 	int i;
59 	int ret;
60 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
61 
62 	msg = kmalloc(sizeof(*msg) + sizeof(*param), GFP_KERNEL);
63 	if (!msg)
64 		return -ENOMEM;
65 
66 	param = (struct ec_params_reboot_ec *)msg->data;
67 
68 	param->flags = 0;
69 	while (1) {
70 		/* Find word to start scanning */
71 		while (buf[offset] && isspace(buf[offset]))
72 			offset++;
73 		if (!buf[offset])
74 			break;
75 
76 		for (i = 0; i < ARRAY_SIZE(words); i++) {
77 			if (!strncasecmp(words[i].str, buf+offset,
78 					 strlen(words[i].str))) {
79 				if (words[i].flags) {
80 					param->flags |= words[i].flags;
81 				} else {
82 					param->cmd = words[i].cmd;
83 					got_cmd = 1;
84 				}
85 				break;
86 			}
87 		}
88 
89 		/* On to the next word, if any */
90 		while (buf[offset] && !isspace(buf[offset]))
91 			offset++;
92 	}
93 
94 	if (!got_cmd) {
95 		count = -EINVAL;
96 		goto exit;
97 	}
98 
99 	msg->version = 0;
100 	msg->command = EC_CMD_REBOOT_EC + ec->cmd_offset;
101 	msg->outsize = sizeof(*param);
102 	msg->insize = 0;
103 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
104 	if (ret < 0)
105 		count = ret;
106 exit:
107 	kfree(msg);
108 	return count;
109 }
110 
111 static ssize_t version_show(struct device *dev,
112 			    struct device_attribute *attr, char *buf)
113 {
114 	static const char * const image_names[] = {"unknown", "RO", "RW"};
115 	struct ec_response_get_version *r_ver;
116 	struct ec_response_get_chip_info *r_chip;
117 	struct ec_response_board_version *r_board;
118 	struct cros_ec_command *msg;
119 	int ret;
120 	int count = 0;
121 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
122 
123 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
124 	if (!msg)
125 		return -ENOMEM;
126 
127 	/* Get versions. RW may change. */
128 	msg->version = 0;
129 	msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
130 	msg->insize = sizeof(*r_ver);
131 	msg->outsize = 0;
132 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
133 	if (ret < 0) {
134 		count = ret;
135 		goto exit;
136 	}
137 	r_ver = (struct ec_response_get_version *)msg->data;
138 	/* Strings should be null-terminated, but let's be sure. */
139 	r_ver->version_string_ro[sizeof(r_ver->version_string_ro) - 1] = '\0';
140 	r_ver->version_string_rw[sizeof(r_ver->version_string_rw) - 1] = '\0';
141 	count += sysfs_emit_at(buf, count, "RO version:    %s\n", r_ver->version_string_ro);
142 	count += sysfs_emit_at(buf, count, "RW version:    %s\n", r_ver->version_string_rw);
143 	count += sysfs_emit_at(buf, count, "Firmware copy: %s\n",
144 			   (r_ver->current_image < ARRAY_SIZE(image_names) ?
145 			    image_names[r_ver->current_image] : "?"));
146 
147 	/* Get build info. */
148 	msg->command = EC_CMD_GET_BUILD_INFO + ec->cmd_offset;
149 	msg->insize = EC_HOST_PARAM_SIZE;
150 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
151 	if (ret < 0) {
152 		count += sysfs_emit_at(buf, count,
153 				   "Build info:    XFER / EC ERROR %d / %d\n",
154 				   ret, msg->result);
155 	} else {
156 		msg->data[EC_HOST_PARAM_SIZE - 1] = '\0';
157 		count += sysfs_emit_at(buf, count, "Build info:    %s\n", msg->data);
158 	}
159 
160 	/* Get chip info. */
161 	msg->command = EC_CMD_GET_CHIP_INFO + ec->cmd_offset;
162 	msg->insize = sizeof(*r_chip);
163 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
164 	if (ret < 0) {
165 		count += sysfs_emit_at(buf, count,
166 				   "Chip info:     XFER / EC ERROR %d / %d\n",
167 				   ret, msg->result);
168 	} else {
169 		r_chip = (struct ec_response_get_chip_info *)msg->data;
170 
171 		r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
172 		r_chip->name[sizeof(r_chip->name) - 1] = '\0';
173 		r_chip->revision[sizeof(r_chip->revision) - 1] = '\0';
174 		count += sysfs_emit_at(buf, count, "Chip vendor:   %s\n", r_chip->vendor);
175 		count += sysfs_emit_at(buf, count, "Chip name:     %s\n", r_chip->name);
176 		count += sysfs_emit_at(buf, count, "Chip revision: %s\n", r_chip->revision);
177 	}
178 
179 	/* Get board version */
180 	msg->command = EC_CMD_GET_BOARD_VERSION + ec->cmd_offset;
181 	msg->insize = sizeof(*r_board);
182 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
183 	if (ret < 0) {
184 		count += sysfs_emit_at(buf, count,
185 				   "Board version: XFER / EC ERROR %d / %d\n",
186 				   ret, msg->result);
187 	} else {
188 		r_board = (struct ec_response_board_version *)msg->data;
189 
190 		count += sysfs_emit_at(buf, count,
191 				   "Board version: %d\n",
192 				   r_board->board_version);
193 	}
194 
195 exit:
196 	kfree(msg);
197 	return count;
198 }
199 
200 static ssize_t flashinfo_show(struct device *dev,
201 			      struct device_attribute *attr, char *buf)
202 {
203 	struct ec_response_flash_info *resp;
204 	struct cros_ec_command *msg;
205 	int ret;
206 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
207 
208 	msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
209 	if (!msg)
210 		return -ENOMEM;
211 
212 	/* The flash info shouldn't ever change, but ask each time anyway. */
213 	msg->version = 0;
214 	msg->command = EC_CMD_FLASH_INFO + ec->cmd_offset;
215 	msg->insize = sizeof(*resp);
216 	msg->outsize = 0;
217 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
218 	if (ret < 0)
219 		goto exit;
220 
221 	resp = (struct ec_response_flash_info *)msg->data;
222 
223 	ret = sysfs_emit(buf,
224 			"FlashSize %d\nWriteSize %d\n"
225 			"EraseSize %d\nProtectSize %d\n",
226 			resp->flash_size, resp->write_block_size,
227 			resp->erase_block_size, resp->protect_block_size);
228 exit:
229 	kfree(msg);
230 	return ret;
231 }
232 
233 /* Keyboard wake angle control */
234 static ssize_t kb_wake_angle_show(struct device *dev,
235 				  struct device_attribute *attr, char *buf)
236 {
237 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
238 	struct ec_response_motion_sense *resp;
239 	struct ec_params_motion_sense *param;
240 	struct cros_ec_command *msg;
241 	int ret;
242 
243 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
244 	if (!msg)
245 		return -ENOMEM;
246 
247 	param = (struct ec_params_motion_sense *)msg->data;
248 	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
249 	msg->version = 2;
250 	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
251 	param->kb_wake_angle.data = EC_MOTION_SENSE_NO_VALUE;
252 	msg->outsize = sizeof(*param);
253 	msg->insize = sizeof(*resp);
254 
255 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
256 	if (ret < 0)
257 		goto exit;
258 
259 	resp = (struct ec_response_motion_sense *)msg->data;
260 	ret = sysfs_emit(buf, "%d\n", resp->kb_wake_angle.ret);
261 exit:
262 	kfree(msg);
263 	return ret;
264 }
265 
266 static ssize_t kb_wake_angle_store(struct device *dev,
267 				   struct device_attribute *attr,
268 				   const char *buf, size_t count)
269 {
270 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
271 	struct ec_params_motion_sense *param;
272 	struct cros_ec_command *msg;
273 	u16 angle;
274 	int ret;
275 
276 	ret = kstrtou16(buf, 0, &angle);
277 	if (ret)
278 		return ret;
279 
280 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
281 	if (!msg)
282 		return -ENOMEM;
283 
284 	param = (struct ec_params_motion_sense *)msg->data;
285 	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
286 	msg->version = 2;
287 	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
288 	param->kb_wake_angle.data = angle;
289 	msg->outsize = sizeof(*param);
290 	msg->insize = sizeof(struct ec_response_motion_sense);
291 
292 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
293 	kfree(msg);
294 	if (ret < 0)
295 		return ret;
296 	return count;
297 }
298 
299 /* Module initialization */
300 
301 static DEVICE_ATTR_RW(reboot);
302 static DEVICE_ATTR_RO(version);
303 static DEVICE_ATTR_RO(flashinfo);
304 static DEVICE_ATTR_RW(kb_wake_angle);
305 
306 static struct attribute *__ec_attrs[] = {
307 	&dev_attr_kb_wake_angle.attr,
308 	&dev_attr_reboot.attr,
309 	&dev_attr_version.attr,
310 	&dev_attr_flashinfo.attr,
311 	NULL,
312 };
313 
314 static umode_t cros_ec_ctrl_visible(struct kobject *kobj,
315 				    struct attribute *a, int n)
316 {
317 	struct device *dev = kobj_to_dev(kobj);
318 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
319 
320 	if (a == &dev_attr_kb_wake_angle.attr && !ec->has_kb_wake_angle)
321 		return 0;
322 
323 	return a->mode;
324 }
325 
326 static const struct attribute_group cros_ec_attr_group = {
327 	.attrs = __ec_attrs,
328 	.is_visible = cros_ec_ctrl_visible,
329 };
330 
331 static int cros_ec_sysfs_probe(struct platform_device *pd)
332 {
333 	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
334 	struct device *dev = &pd->dev;
335 	int ret;
336 
337 	ret = sysfs_create_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
338 	if (ret < 0)
339 		dev_err(dev, "failed to create attributes. err=%d\n", ret);
340 
341 	return ret;
342 }
343 
344 static void cros_ec_sysfs_remove(struct platform_device *pd)
345 {
346 	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
347 
348 	sysfs_remove_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
349 }
350 
351 static const struct platform_device_id cros_ec_sysfs_id[] = {
352 	{ DRV_NAME, 0 },
353 	{}
354 };
355 MODULE_DEVICE_TABLE(platform, cros_ec_sysfs_id);
356 
357 static struct platform_driver cros_ec_sysfs_driver = {
358 	.driver = {
359 		.name = DRV_NAME,
360 	},
361 	.probe = cros_ec_sysfs_probe,
362 	.remove = cros_ec_sysfs_remove,
363 	.id_table = cros_ec_sysfs_id,
364 };
365 
366 module_platform_driver(cros_ec_sysfs_driver);
367 
368 MODULE_LICENSE("GPL");
369 MODULE_DESCRIPTION("Expose the ChromeOS EC through sysfs");
370