drivers/platform/chrome/wilco_ec/sysfs.c

   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/platform_data/wilco-ec.h>
  12 #include <linux/sysfs.h>
  13
  14 #define CMD_KB_CMOS                     0x7C
  15 #define SUB_CMD_KB_CMOS_AUTO_ON         0x03
  16
  17 struct boot_on_ac_request {
  18         u8 cmd;                 /* Always CMD_KB_CMOS */
  19         u8 reserved1;
  20         u8 sub_cmd;             /* Always SUB_CMD_KB_CMOS_AUTO_ON */
  21         u8 reserved3to5[3];
  22         u8 val;                 /* Either 0 or 1 */
  23         u8 reserved7;
  24 } __packed;
  25
  26 #define CMD_EC_INFO                     0x38
  27 enum get_ec_info_op {
  28         CMD_GET_EC_LABEL        = 0,
  29         CMD_GET_EC_REV          = 1,
  30         CMD_GET_EC_MODEL        = 2,
  31         CMD_GET_EC_BUILD_DATE   = 3,
  32 };
  33
  34 struct get_ec_info_req {
  35         u8 cmd;                 /* Always CMD_EC_INFO */
  36         u8 reserved;
  37         u8 op;                  /* One of enum get_ec_info_op */
  38 } __packed;
  39
  40 struct get_ec_info_resp {
  41         u8 reserved[2];
  42         char value[9]; /* __nonstring: might not be null terminated */
  43 } __packed;
  44
  45 static ssize_t boot_on_ac_store(struct device *dev,
  46                                 struct device_attribute *attr,
  47                                 const char *buf, size_t count)
  48 {
  49         struct wilco_ec_device *ec = dev_get_drvdata(dev);
  50         struct boot_on_ac_request rq;
  51         struct wilco_ec_message msg;
  52         int ret;
  53         u8 val;
  54
  55         ret = kstrtou8(buf, 10, &val);
  56         if (ret < 0)
  57                 return ret;
  58         if (val > 1)
  59                 return -EINVAL;
  60
  61         memset(&rq, 0, sizeof(rq));
  62         rq.cmd = CMD_KB_CMOS;
  63         rq.sub_cmd = SUB_CMD_KB_CMOS_AUTO_ON;
  64         rq.val = val;
  65
  66         memset(&msg, 0, sizeof(msg));
  67         msg.type = WILCO_EC_MSG_LEGACY;
  68         msg.request_data = &rq;
  69         msg.request_size = sizeof(rq);
  70         ret = wilco_ec_mailbox(ec, &msg);
  71         if (ret < 0)
  72                 return ret;
  73
  74         return count;
  75 }
  76
  77 static DEVICE_ATTR_WO(boot_on_ac);
  78
  79 static ssize_t get_info(struct device *dev, char *buf, enum get_ec_info_op op)
  80 {
  81         struct wilco_ec_device *ec = dev_get_drvdata(dev);
  82         struct get_ec_info_req req = { .cmd = CMD_EC_INFO, .op = op };
  83         struct get_ec_info_resp resp;
  84         int ret;
  85
  86         struct wilco_ec_message msg = {
  87                 .type = WILCO_EC_MSG_LEGACY,
  88                 .request_data = &req,
  89                 .request_size = sizeof(req),
  90                 .response_data = &resp,
  91                 .response_size = sizeof(resp),
  92         };
  93
  94         ret = wilco_ec_mailbox(ec, &msg);
  95         if (ret < 0)
  96                 return ret;
  97
  98         return scnprintf(buf, PAGE_SIZE, "%.*s\n", (int)sizeof(resp.value),
  99                          (char *)&resp.value);
 100 }
 101
 102 static ssize_t version_show(struct device *dev, struct device_attribute *attr,
 103                           char *buf)
 104 {
 105         return get_info(dev, buf, CMD_GET_EC_LABEL);
 106 }
 107
 108 static DEVICE_ATTR_RO(version);
 109
 110 static ssize_t build_revision_show(struct device *dev,
 111                                    struct device_attribute *attr, char *buf)
 112 {
 113         return get_info(dev, buf, CMD_GET_EC_REV);
 114 }
 115
 116 static DEVICE_ATTR_RO(build_revision);
 117
 118 static ssize_t build_date_show(struct device *dev,
 119                                struct device_attribute *attr, char *buf)
 120 {
 121         return get_info(dev, buf, CMD_GET_EC_BUILD_DATE);
 122 }
 123
 124 static DEVICE_ATTR_RO(build_date);
 125
 126 static ssize_t model_number_show(struct device *dev,
 127                                  struct device_attribute *attr, char *buf)
 128 {
 129         return get_info(dev, buf, CMD_GET_EC_MODEL);
 130 }
 131
 132 static DEVICE_ATTR_RO(model_number);
 133
 134
 135 static struct attribute *wilco_dev_attrs[] = {
 136         &dev_attr_boot_on_ac.attr,
 137         &dev_attr_build_date.attr,
 138         &dev_attr_build_revision.attr,
 139         &dev_attr_model_number.attr,
 140         &dev_attr_version.attr,
 141         NULL,
 142 };
 143
 144 static struct attribute_group wilco_dev_attr_group = {
 145         .attrs = wilco_dev_attrs,
 146 };
 147
 148 int wilco_ec_add_sysfs(struct wilco_ec_device *ec)
 149 {
 150         return sysfs_create_group(&ec->dev->kobj, &wilco_dev_attr_group);
 151 }
 152
 153 void wilco_ec_remove_sysfs(struct wilco_ec_device *ec)
 154 {
 155         sysfs_remove_group(&ec->dev->kobj, &wilco_dev_attr_group);
 156 }