1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2019 Google LLC
4  *
5  * Sysfs properties to view and modify EC-controlled features on Wilco devices.
6  * The entries will appear under /sys/bus/platform/devices/GOOG000C:00/
7  *
8  * See Documentation/ABI/testing/sysfs-platform-wilco-ec for more information.
9  */
10 
11 #include <linux/device.h>
12 #include <linux/kernel.h>
13 #include <linux/platform_data/wilco-ec.h>
14 #include <linux/string.h>
15 #include <linux/sysfs.h>
16 #include <linux/types.h>
17 
18 #define CMD_KB_CMOS			0x7C
19 #define SUB_CMD_KB_CMOS_AUTO_ON		0x03
20 
21 struct boot_on_ac_request {
22 	u8 cmd;			/* Always CMD_KB_CMOS */
23 	u8 reserved1;
24 	u8 sub_cmd;		/* Always SUB_CMD_KB_CMOS_AUTO_ON */
25 	u8 reserved3to5[3];
26 	u8 val;			/* Either 0 or 1 */
27 	u8 reserved7;
28 } __packed;
29 
30 #define CMD_USB_CHARGE 0x39
31 
32 enum usb_charge_op {
33 	USB_CHARGE_GET = 0,
34 	USB_CHARGE_SET = 1,
35 };
36 
37 struct usb_charge_request {
38 	u8 cmd;		/* Always CMD_USB_CHARGE */
39 	u8 reserved;
40 	u8 op;		/* One of enum usb_charge_op */
41 	u8 val;		/* When setting, either 0 or 1 */
42 } __packed;
43 
44 struct usb_charge_response {
45 	u8 reserved;
46 	u8 status;	/* Set by EC to 0 on success, other value on failure */
47 	u8 val;		/* When getting, set by EC to either 0 or 1 */
48 } __packed;
49 
50 #define CMD_EC_INFO			0x38
51 enum get_ec_info_op {
52 	CMD_GET_EC_LABEL	= 0,
53 	CMD_GET_EC_REV		= 1,
54 	CMD_GET_EC_MODEL	= 2,
55 	CMD_GET_EC_BUILD_DATE	= 3,
56 };
57 
58 struct get_ec_info_req {
59 	u8 cmd;			/* Always CMD_EC_INFO */
60 	u8 reserved;
61 	u8 op;			/* One of enum get_ec_info_op */
62 } __packed;
63 
64 struct get_ec_info_resp {
65 	u8 reserved[2];
66 	char value[9]; /* __nonstring: might not be null terminated */
67 } __packed;
68 
69 static ssize_t boot_on_ac_store(struct device *dev,
70 				struct device_attribute *attr,
71 				const char *buf, size_t count)
72 {
73 	struct wilco_ec_device *ec = dev_get_drvdata(dev);
74 	struct boot_on_ac_request rq;
75 	struct wilco_ec_message msg;
76 	int ret;
77 	u8 val;
78 
79 	ret = kstrtou8(buf, 10, &val);
80 	if (ret < 0)
81 		return ret;
82 	if (val > 1)
83 		return -EINVAL;
84 
85 	memset(&rq, 0, sizeof(rq));
86 	rq.cmd = CMD_KB_CMOS;
87 	rq.sub_cmd = SUB_CMD_KB_CMOS_AUTO_ON;
88 	rq.val = val;
89 
90 	memset(&msg, 0, sizeof(msg));
91 	msg.type = WILCO_EC_MSG_LEGACY;
92 	msg.request_data = &rq;
93 	msg.request_size = sizeof(rq);
94 	ret = wilco_ec_mailbox(ec, &msg);
95 	if (ret < 0)
96 		return ret;
97 
98 	return count;
99 }
100 
101 static DEVICE_ATTR_WO(boot_on_ac);
102 
103 static ssize_t get_info(struct device *dev, char *buf, enum get_ec_info_op op)
104 {
105 	struct wilco_ec_device *ec = dev_get_drvdata(dev);
106 	struct get_ec_info_req req = { .cmd = CMD_EC_INFO, .op = op };
107 	struct get_ec_info_resp resp;
108 	int ret;
109 
110 	struct wilco_ec_message msg = {
111 		.type = WILCO_EC_MSG_LEGACY,
112 		.request_data = &req,
113 		.request_size = sizeof(req),
114 		.response_data = &resp,
115 		.response_size = sizeof(resp),
116 	};
117 
118 	ret = wilco_ec_mailbox(ec, &msg);
119 	if (ret < 0)
120 		return ret;
121 
122 	return sysfs_emit(buf, "%.*s\n", (int)sizeof(resp.value), (char *)&resp.value);
123 }
124 
125 static ssize_t version_show(struct device *dev, struct device_attribute *attr,
126 			  char *buf)
127 {
128 	return get_info(dev, buf, CMD_GET_EC_LABEL);
129 }
130 
131 static DEVICE_ATTR_RO(version);
132 
133 static ssize_t build_revision_show(struct device *dev,
134 				   struct device_attribute *attr, char *buf)
135 {
136 	return get_info(dev, buf, CMD_GET_EC_REV);
137 }
138 
139 static DEVICE_ATTR_RO(build_revision);
140 
141 static ssize_t build_date_show(struct device *dev,
142 			       struct device_attribute *attr, char *buf)
143 {
144 	return get_info(dev, buf, CMD_GET_EC_BUILD_DATE);
145 }
146 
147 static DEVICE_ATTR_RO(build_date);
148 
149 static ssize_t model_number_show(struct device *dev,
150 				 struct device_attribute *attr, char *buf)
151 {
152 	return get_info(dev, buf, CMD_GET_EC_MODEL);
153 }
154 
155 static DEVICE_ATTR_RO(model_number);
156 
157 static int send_usb_charge(struct wilco_ec_device *ec,
158 				struct usb_charge_request *rq,
159 				struct usb_charge_response *rs)
160 {
161 	struct wilco_ec_message msg;
162 	int ret;
163 
164 	memset(&msg, 0, sizeof(msg));
165 	msg.type = WILCO_EC_MSG_LEGACY;
166 	msg.request_data = rq;
167 	msg.request_size = sizeof(*rq);
168 	msg.response_data = rs;
169 	msg.response_size = sizeof(*rs);
170 	ret = wilco_ec_mailbox(ec, &msg);
171 	if (ret < 0)
172 		return ret;
173 	if (rs->status)
174 		return -EIO;
175 
176 	return 0;
177 }
178 
179 static ssize_t usb_charge_show(struct device *dev,
180 				    struct device_attribute *attr, char *buf)
181 {
182 	struct wilco_ec_device *ec = dev_get_drvdata(dev);
183 	struct usb_charge_request rq;
184 	struct usb_charge_response rs;
185 	int ret;
186 
187 	memset(&rq, 0, sizeof(rq));
188 	rq.cmd = CMD_USB_CHARGE;
189 	rq.op = USB_CHARGE_GET;
190 
191 	ret = send_usb_charge(ec, &rq, &rs);
192 	if (ret < 0)
193 		return ret;
194 
195 	return sprintf(buf, "%d\n", rs.val);
196 }
197 
198 static ssize_t usb_charge_store(struct device *dev,
199 				     struct device_attribute *attr,
200 				     const char *buf, size_t count)
201 {
202 	struct wilco_ec_device *ec = dev_get_drvdata(dev);
203 	struct usb_charge_request rq;
204 	struct usb_charge_response rs;
205 	int ret;
206 	u8 val;
207 
208 	ret = kstrtou8(buf, 10, &val);
209 	if (ret < 0)
210 		return ret;
211 	if (val > 1)
212 		return -EINVAL;
213 
214 	memset(&rq, 0, sizeof(rq));
215 	rq.cmd = CMD_USB_CHARGE;
216 	rq.op = USB_CHARGE_SET;
217 	rq.val = val;
218 
219 	ret = send_usb_charge(ec, &rq, &rs);
220 	if (ret < 0)
221 		return ret;
222 
223 	return count;
224 }
225 
226 static DEVICE_ATTR_RW(usb_charge);
227 
228 static struct attribute *wilco_dev_attrs[] = {
229 	&dev_attr_boot_on_ac.attr,
230 	&dev_attr_build_date.attr,
231 	&dev_attr_build_revision.attr,
232 	&dev_attr_model_number.attr,
233 	&dev_attr_usb_charge.attr,
234 	&dev_attr_version.attr,
235 	NULL,
236 };
237 
238 static const struct attribute_group wilco_dev_attr_group = {
239 	.attrs = wilco_dev_attrs,
240 };
241 
242 int wilco_ec_add_sysfs(struct wilco_ec_device *ec)
243 {
244 	return sysfs_create_group(&ec->dev->kobj, &wilco_dev_attr_group);
245 }
246 
247 void wilco_ec_remove_sysfs(struct wilco_ec_device *ec)
248 {
249 	sysfs_remove_group(&ec->dev->kobj, &wilco_dev_attr_group);
250 }
251