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/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 += scnprintf(buf + count, PAGE_SIZE - count,
32 			   "ro|rw|cancel|cold|disable-jump|hibernate");
33 	count += scnprintf(buf + count, PAGE_SIZE - count,
34 			   " [at-shutdown]\n");
35 	return count;
36 }
37 
38 static ssize_t reboot_store(struct device *dev,
39 			    struct device_attribute *attr,
40 			    const char *buf, size_t count)
41 {
42 	static const struct {
43 		const char * const str;
44 		uint8_t cmd;
45 		uint8_t flags;
46 	} words[] = {
47 		{"cancel",       EC_REBOOT_CANCEL, 0},
48 		{"ro",           EC_REBOOT_JUMP_RO, 0},
49 		{"rw",           EC_REBOOT_JUMP_RW, 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 += scnprintf(buf + count, PAGE_SIZE - count,
142 			   "RO version:    %s\n", r_ver->version_string_ro);
143 	count += scnprintf(buf + count, PAGE_SIZE - count,
144 			   "RW version:    %s\n", r_ver->version_string_rw);
145 	count += scnprintf(buf + count, PAGE_SIZE - count,
146 			   "Firmware copy: %s\n",
147 			   (r_ver->current_image < ARRAY_SIZE(image_names) ?
148 			    image_names[r_ver->current_image] : "?"));
149 
150 	/* Get build info. */
151 	msg->command = EC_CMD_GET_BUILD_INFO + ec->cmd_offset;
152 	msg->insize = EC_HOST_PARAM_SIZE;
153 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
154 	if (ret < 0)
155 		count += scnprintf(buf + count, PAGE_SIZE - count,
156 				   "Build info:    XFER ERROR %d\n", ret);
157 	else if (msg->result != EC_RES_SUCCESS)
158 		count += scnprintf(buf + count, PAGE_SIZE - count,
159 				   "Build info:    EC error %d\n", msg->result);
160 	else {
161 		msg->data[EC_HOST_PARAM_SIZE - 1] = '\0';
162 		count += scnprintf(buf + count, PAGE_SIZE - count,
163 				   "Build info:    %s\n", msg->data);
164 	}
165 
166 	/* Get chip info. */
167 	msg->command = EC_CMD_GET_CHIP_INFO + ec->cmd_offset;
168 	msg->insize = sizeof(*r_chip);
169 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
170 	if (ret < 0)
171 		count += scnprintf(buf + count, PAGE_SIZE - count,
172 				   "Chip info:     XFER ERROR %d\n", ret);
173 	else if (msg->result != EC_RES_SUCCESS)
174 		count += scnprintf(buf + count, PAGE_SIZE - count,
175 				   "Chip info:     EC error %d\n", msg->result);
176 	else {
177 		r_chip = (struct ec_response_get_chip_info *)msg->data;
178 
179 		r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
180 		r_chip->name[sizeof(r_chip->name) - 1] = '\0';
181 		r_chip->revision[sizeof(r_chip->revision) - 1] = '\0';
182 		count += scnprintf(buf + count, PAGE_SIZE - count,
183 				   "Chip vendor:   %s\n", r_chip->vendor);
184 		count += scnprintf(buf + count, PAGE_SIZE - count,
185 				   "Chip name:     %s\n", r_chip->name);
186 		count += scnprintf(buf + count, PAGE_SIZE - count,
187 				   "Chip revision: %s\n", r_chip->revision);
188 	}
189 
190 	/* Get board version */
191 	msg->command = EC_CMD_GET_BOARD_VERSION + ec->cmd_offset;
192 	msg->insize = sizeof(*r_board);
193 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
194 	if (ret < 0)
195 		count += scnprintf(buf + count, PAGE_SIZE - count,
196 				   "Board version: XFER ERROR %d\n", ret);
197 	else if (msg->result != EC_RES_SUCCESS)
198 		count += scnprintf(buf + count, PAGE_SIZE - count,
199 				   "Board version: EC error %d\n", msg->result);
200 	else {
201 		r_board = (struct ec_response_board_version *)msg->data;
202 
203 		count += scnprintf(buf + count, PAGE_SIZE - count,
204 				   "Board version: %d\n",
205 				   r_board->board_version);
206 	}
207 
208 exit:
209 	kfree(msg);
210 	return count;
211 }
212 
213 static ssize_t flashinfo_show(struct device *dev,
214 			      struct device_attribute *attr, char *buf)
215 {
216 	struct ec_response_flash_info *resp;
217 	struct cros_ec_command *msg;
218 	int ret;
219 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
220 
221 	msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
222 	if (!msg)
223 		return -ENOMEM;
224 
225 	/* The flash info shouldn't ever change, but ask each time anyway. */
226 	msg->version = 0;
227 	msg->command = EC_CMD_FLASH_INFO + ec->cmd_offset;
228 	msg->insize = sizeof(*resp);
229 	msg->outsize = 0;
230 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
231 	if (ret < 0)
232 		goto exit;
233 
234 	resp = (struct ec_response_flash_info *)msg->data;
235 
236 	ret = scnprintf(buf, PAGE_SIZE,
237 			"FlashSize %d\nWriteSize %d\n"
238 			"EraseSize %d\nProtectSize %d\n",
239 			resp->flash_size, resp->write_block_size,
240 			resp->erase_block_size, resp->protect_block_size);
241 exit:
242 	kfree(msg);
243 	return ret;
244 }
245 
246 /* Keyboard wake angle control */
247 static ssize_t kb_wake_angle_show(struct device *dev,
248 				  struct device_attribute *attr, char *buf)
249 {
250 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
251 	struct ec_response_motion_sense *resp;
252 	struct ec_params_motion_sense *param;
253 	struct cros_ec_command *msg;
254 	int ret;
255 
256 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
257 	if (!msg)
258 		return -ENOMEM;
259 
260 	param = (struct ec_params_motion_sense *)msg->data;
261 	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
262 	msg->version = 2;
263 	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
264 	param->kb_wake_angle.data = EC_MOTION_SENSE_NO_VALUE;
265 	msg->outsize = sizeof(*param);
266 	msg->insize = sizeof(*resp);
267 
268 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
269 	if (ret < 0)
270 		goto exit;
271 
272 	resp = (struct ec_response_motion_sense *)msg->data;
273 	ret = scnprintf(buf, PAGE_SIZE, "%d\n", resp->kb_wake_angle.ret);
274 exit:
275 	kfree(msg);
276 	return ret;
277 }
278 
279 static ssize_t kb_wake_angle_store(struct device *dev,
280 				   struct device_attribute *attr,
281 				   const char *buf, size_t count)
282 {
283 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
284 	struct ec_params_motion_sense *param;
285 	struct cros_ec_command *msg;
286 	u16 angle;
287 	int ret;
288 
289 	ret = kstrtou16(buf, 0, &angle);
290 	if (ret)
291 		return ret;
292 
293 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
294 	if (!msg)
295 		return -ENOMEM;
296 
297 	param = (struct ec_params_motion_sense *)msg->data;
298 	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
299 	msg->version = 2;
300 	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
301 	param->kb_wake_angle.data = angle;
302 	msg->outsize = sizeof(*param);
303 	msg->insize = sizeof(struct ec_response_motion_sense);
304 
305 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
306 	kfree(msg);
307 	if (ret < 0)
308 		return ret;
309 	return count;
310 }
311 
312 /* Module initialization */
313 
314 static DEVICE_ATTR_RW(reboot);
315 static DEVICE_ATTR_RO(version);
316 static DEVICE_ATTR_RO(flashinfo);
317 static DEVICE_ATTR_RW(kb_wake_angle);
318 
319 static struct attribute *__ec_attrs[] = {
320 	&dev_attr_kb_wake_angle.attr,
321 	&dev_attr_reboot.attr,
322 	&dev_attr_version.attr,
323 	&dev_attr_flashinfo.attr,
324 	NULL,
325 };
326 
327 static umode_t cros_ec_ctrl_visible(struct kobject *kobj,
328 				    struct attribute *a, int n)
329 {
330 	struct device *dev = container_of(kobj, struct device, kobj);
331 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
332 
333 	if (a == &dev_attr_kb_wake_angle.attr && !ec->has_kb_wake_angle)
334 		return 0;
335 
336 	return a->mode;
337 }
338 
339 static struct attribute_group cros_ec_attr_group = {
340 	.attrs = __ec_attrs,
341 	.is_visible = cros_ec_ctrl_visible,
342 };
343 
344 static int cros_ec_sysfs_probe(struct platform_device *pd)
345 {
346 	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
347 	struct device *dev = &pd->dev;
348 	int ret;
349 
350 	ret = sysfs_create_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
351 	if (ret < 0)
352 		dev_err(dev, "failed to create attributes. err=%d\n", ret);
353 
354 	return ret;
355 }
356 
357 static int cros_ec_sysfs_remove(struct platform_device *pd)
358 {
359 	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
360 
361 	sysfs_remove_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
362 
363 	return 0;
364 }
365 
366 static struct platform_driver cros_ec_sysfs_driver = {
367 	.driver = {
368 		.name = DRV_NAME,
369 	},
370 	.probe = cros_ec_sysfs_probe,
371 	.remove = cros_ec_sysfs_remove,
372 };
373 
374 module_platform_driver(cros_ec_sysfs_driver);
375 
376 MODULE_LICENSE("GPL");
377 MODULE_DESCRIPTION("Expose the ChromeOS EC through sysfs");
378 MODULE_ALIAS("platform:" DRV_NAME);
379