kernel/drivers/platform/chrome/cros_ec_sysfs.c

   1 /*
   2  * cros_ec_sysfs - expose the Chrome OS EC through sysfs
   3  *
   4  * Copyright (C) 2014 Google, Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #define pr_fmt(fmt) "cros_ec_sysfs: " fmt
  21
  22 #include <linux/ctype.h>
  23 #include <linux/delay.h>
  24 #include <linux/device.h>
  25 #include <linux/fs.h>
  26 #include <linux/kobject.h>
  27 #include <linux/mfd/cros_ec.h>
  28 #include <linux/mfd/cros_ec_commands.h>
  29 #include <linux/module.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/printk.h>
  32 #include <linux/stat.h>
  33 #include <linux/types.h>
  34 #include <linux/uaccess.h>
  35
  36 #include "cros_ec_dev.h"
  37
  38 /* Accessor functions */
  39
  40 static ssize_t show_ec_reboot(struct device *dev,
  41                               struct device_attribute *attr, char *buf)
  42 {
  43         int count = 0;
  44
  45         count += scnprintf(buf + count, PAGE_SIZE - count,
  46                            "ro|rw|cancel|cold|disable-jump|hibernate");
  47         count += scnprintf(buf + count, PAGE_SIZE - count,
  48                            " [at-shutdown]\n");
  49         return count;
  50 }
  51
  52 static ssize_t store_ec_reboot(struct device *dev,
  53                                struct device_attribute *attr,
  54                                const char *buf, size_t count)
  55 {
  56         static const struct {
  57                 const char * const str;
  58                 uint8_t cmd;
  59                 uint8_t flags;
  60         } words[] = {
  61                 {"cancel",       EC_REBOOT_CANCEL, 0},
  62                 {"ro",           EC_REBOOT_JUMP_RO, 0},
  63                 {"rw",           EC_REBOOT_JUMP_RW, 0},
  64                 {"cold",         EC_REBOOT_COLD, 0},
  65                 {"disable-jump", EC_REBOOT_DISABLE_JUMP, 0},
  66                 {"hibernate",    EC_REBOOT_HIBERNATE, 0},
  67                 {"at-shutdown",  -1, EC_REBOOT_FLAG_ON_AP_SHUTDOWN},
  68         };
  69         struct cros_ec_command msg = { 0 };
  70         struct ec_params_reboot_ec *param =
  71                 (struct ec_params_reboot_ec *)msg.outdata;
  72         int got_cmd = 0, offset = 0;
  73         int i;
  74         int ret;
  75         struct cros_ec_device *ec = dev_get_drvdata(dev);
  76
  77         param->flags = 0;
  78         while (1) {
  79                 /* Find word to start scanning */
  80                 while (buf[offset] && isspace(buf[offset]))
  81                         offset++;
  82                 if (!buf[offset])
  83                         break;
  84
  85                 for (i = 0; i < ARRAY_SIZE(words); i++) {
  86                         if (!strncasecmp(words[i].str, buf+offset,
  87                                          strlen(words[i].str))) {
  88                                 if (words[i].flags) {
  89                                         param->flags |= words[i].flags;
  90                                 } else {
  91                                         param->cmd = words[i].cmd;
  92                                         got_cmd = 1;
  93                                 }
  94                                 break;
  95                         }
  96                 }
  97
  98                 /* On to the next word, if any */
  99                 while (buf[offset] && !isspace(buf[offset]))
 100                         offset++;
 101         }
 102
 103         if (!got_cmd)
 104                 return -EINVAL;
 105
 106         msg.command = EC_CMD_REBOOT_EC;
 107         msg.outsize = sizeof(param);
 108         ret = cros_ec_cmd_xfer(ec, &msg);
 109         if (ret < 0)
 110                 return ret;
 111         if (msg.result != EC_RES_SUCCESS) {
 112                 dev_dbg(ec->dev, "EC result %d\n", msg.result);
 113                 return -EINVAL;
 114         }
 115
 116         return count;
 117 }
 118
 119 static ssize_t show_ec_version(struct device *dev,
 120                                struct device_attribute *attr, char *buf)
 121 {
 122         static const char * const image_names[] = {"unknown", "RO", "RW"};
 123         struct ec_response_get_version *r_ver;
 124         struct ec_response_get_chip_info *r_chip;
 125         struct ec_response_board_version *r_board;
 126         struct cros_ec_command msg = { 0 };
 127         int ret;
 128         int count = 0;
 129         struct cros_ec_device *ec = dev_get_drvdata(dev);
 130
 131         /* Get versions. RW may change. */
 132         msg.command = EC_CMD_GET_VERSION;
 133         msg.insize = sizeof(*r_ver);
 134         ret = cros_ec_cmd_xfer(ec, &msg);
 135         if (ret < 0)
 136                 return ret;
 137         if (msg.result != EC_RES_SUCCESS)
 138                 return scnprintf(buf, PAGE_SIZE,
 139                                  "ERROR: EC returned %d\n", msg.result);
 140
 141         r_ver = (struct ec_response_get_version *)msg.indata;
 142         /* Strings should be null-terminated, but let's be sure. */
 143         r_ver->version_string_ro[sizeof(r_ver->version_string_ro) - 1] = '\0';
 144         r_ver->version_string_rw[sizeof(r_ver->version_string_rw) - 1] = '\0';
 145         count += scnprintf(buf + count, PAGE_SIZE - count,
 146                            "RO version:    %s\n", r_ver->version_string_ro);
 147         count += scnprintf(buf + count, PAGE_SIZE - count,
 148                            "RW version:    %s\n", r_ver->version_string_rw);
 149         count += scnprintf(buf + count, PAGE_SIZE - count,
 150                            "Firmware copy: %s\n",
 151                            (r_ver->current_image < ARRAY_SIZE(image_names) ?
 152                             image_names[r_ver->current_image] : "?"));
 153
 154         /* Get build info. */
 155         msg.command = EC_CMD_GET_BUILD_INFO;
 156         msg.insize = sizeof(msg.indata);
 157         ret = cros_ec_cmd_xfer(ec, &msg);
 158         if (ret < 0)
 159                 count += scnprintf(buf + count, PAGE_SIZE - count,
 160                                    "Build info:    XFER ERROR %d\n", ret);
 161         else if (msg.result != EC_RES_SUCCESS)
 162                 count += scnprintf(buf + count, PAGE_SIZE - count,
 163                                    "Build info:    EC error %d\n", msg.result);
 164         else {
 165                 msg.indata[sizeof(msg.indata) - 1] = '\0';
 166                 count += scnprintf(buf + count, PAGE_SIZE - count,
 167                                    "Build info:    %s\n", msg.indata);
 168         }
 169
 170         /* Get chip info. */
 171         msg.command = EC_CMD_GET_CHIP_INFO;
 172         msg.insize = sizeof(*r_chip);
 173         ret = cros_ec_cmd_xfer(ec, &msg);
 174         if (ret < 0)
 175                 count += scnprintf(buf + count, PAGE_SIZE - count,
 176                                    "Chip info:     XFER ERROR %d\n", ret);
 177         else if (msg.result != EC_RES_SUCCESS)
 178                 count += scnprintf(buf + count, PAGE_SIZE - count,
 179                                    "Chip info:     EC error %d\n", msg.result);
 180         else {
 181                 r_chip = (struct ec_response_get_chip_info *)msg.indata;
 182
 183                 r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
 184                 r_chip->name[sizeof(r_chip->name) - 1] = '\0';
 185                 r_chip->revision[sizeof(r_chip->revision) - 1] = '\0';
 186                 count += scnprintf(buf + count, PAGE_SIZE - count,
 187                                    "Chip vendor:   %s\n", r_chip->vendor);
 188                 count += scnprintf(buf + count, PAGE_SIZE - count,
 189                                    "Chip name:     %s\n", r_chip->name);
 190                 count += scnprintf(buf + count, PAGE_SIZE - count,
 191                                    "Chip revision: %s\n", r_chip->revision);
 192         }
 193
 194         /* Get board version */
 195         msg.command = EC_CMD_GET_BOARD_VERSION;
 196         msg.insize = sizeof(*r_board);
 197         ret = cros_ec_cmd_xfer(ec, &msg);
 198         if (ret < 0)
 199                 count += scnprintf(buf + count, PAGE_SIZE - count,
 200                                    "Board version: XFER ERROR %d\n", ret);
 201         else if (msg.result != EC_RES_SUCCESS)
 202                 count += scnprintf(buf + count, PAGE_SIZE - count,
 203                                    "Board version: EC error %d\n", msg.result);
 204         else {
 205                 r_board = (struct ec_response_board_version *)msg.indata;
 206
 207                 count += scnprintf(buf + count, PAGE_SIZE - count,
 208                                    "Board version: %d\n",
 209                                    r_board->board_version);
 210         }
 211
 212         return count;
 213 }
 214
 215 static ssize_t show_ec_flashinfo(struct device *dev,
 216                                  struct device_attribute *attr, char *buf)
 217 {
 218         struct ec_response_flash_info *resp;
 219         struct cros_ec_command msg = { 0 };
 220         int ret;
 221         struct cros_ec_device *ec = dev_get_drvdata(dev);
 222
 223         /* The flash info shouldn't ever change, but ask each time anyway. */
 224         msg.command = EC_CMD_FLASH_INFO;
 225         msg.insize = sizeof(*resp);
 226         ret = cros_ec_cmd_xfer(ec, &msg);
 227         if (ret < 0)
 228                 return ret;
 229         if (msg.result != EC_RES_SUCCESS)
 230                 return scnprintf(buf, PAGE_SIZE,
 231                                  "ERROR: EC returned %d\n", msg.result);
 232
 233         resp = (struct ec_response_flash_info *)msg.indata;
 234
 235         return scnprintf(buf, PAGE_SIZE,
 236                          "FlashSize %d\nWriteSize %d\n"
 237                          "EraseSize %d\nProtectSize %d\n",
 238                          resp->flash_size, resp->write_block_size,
 239                          resp->erase_block_size, resp->protect_block_size);
 240 }
 241
 242 /* Module initialization */
 243
 244 static DEVICE_ATTR(reboot, S_IWUSR | S_IRUGO, show_ec_reboot, store_ec_reboot);
 245 static DEVICE_ATTR(version, S_IRUGO, show_ec_version, NULL);
 246 static DEVICE_ATTR(flashinfo, S_IRUGO, show_ec_flashinfo, NULL);
 247
 248 static struct attribute *__ec_attrs[] = {
 249         &dev_attr_reboot.attr,
 250         &dev_attr_version.attr,
 251         &dev_attr_flashinfo.attr,
 252         NULL,
 253 };
 254
 255 static struct attribute_group ec_attr_group = {
 256         .attrs = __ec_attrs,
 257 };
 258
 259 void ec_dev_sysfs_init(struct cros_ec_device *ec)
 260 {
 261         int error;
 262
 263         error = sysfs_create_group(&ec->vdev->kobj, &ec_attr_group);
 264         if (error)
 265                 pr_warn("failed to create group: %d\n", error);
 266 }
 267
 268 void ec_dev_sysfs_remove(struct cros_ec_device *ec)
 269 {
 270         sysfs_remove_group(&ec->vdev->kobj, &ec_attr_group);
 271 }