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/slab.h>
  33 #include <linux/stat.h>
  34 #include <linux/types.h>
  35 #include <linux/uaccess.h>
  36
  37 /* Accessor functions */
  38
  39 static ssize_t show_ec_reboot(struct device *dev,
  40                               struct device_attribute *attr, char *buf)
  41 {
  42         int count = 0;
  43
  44         count += scnprintf(buf + count, PAGE_SIZE - count,
  45                            "ro|rw|cancel|cold|disable-jump|hibernate");
  46         count += scnprintf(buf + count, PAGE_SIZE - count,
  47                            " [at-shutdown]\n");
  48         return count;
  49 }
  50
  51 static ssize_t store_ec_reboot(struct device *dev,
  52                                struct device_attribute *attr,
  53                                const char *buf, size_t count)
  54 {
  55         static const struct {
  56                 const char * const str;
  57                 uint8_t cmd;
  58                 uint8_t flags;
  59         } words[] = {
  60                 {"cancel",       EC_REBOOT_CANCEL, 0},
  61                 {"ro",           EC_REBOOT_JUMP_RO, 0},
  62                 {"rw",           EC_REBOOT_JUMP_RW, 0},
  63                 {"cold",         EC_REBOOT_COLD, 0},
  64                 {"disable-jump", EC_REBOOT_DISABLE_JUMP, 0},
  65                 {"hibernate",    EC_REBOOT_HIBERNATE, 0},
  66                 {"at-shutdown",  -1, EC_REBOOT_FLAG_ON_AP_SHUTDOWN},
  67         };
  68         struct cros_ec_command *msg;
  69         struct ec_params_reboot_ec *param;
  70         int got_cmd = 0, offset = 0;
  71         int i;
  72         int ret;
  73         struct cros_ec_dev *ec = container_of(dev,
  74                                               struct cros_ec_dev, class_dev);
  75
  76         msg = kmalloc(sizeof(*msg) + sizeof(*param), GFP_KERNEL);
  77         if (!msg)
  78                 return -ENOMEM;
  79
  80         param = (struct ec_params_reboot_ec *)msg->data;
  81
  82         param->flags = 0;
  83         while (1) {
  84                 /* Find word to start scanning */
  85                 while (buf[offset] && isspace(buf[offset]))
  86                         offset++;
  87                 if (!buf[offset])
  88                         break;
  89
  90                 for (i = 0; i < ARRAY_SIZE(words); i++) {
  91                         if (!strncasecmp(words[i].str, buf+offset,
  92                                          strlen(words[i].str))) {
  93                                 if (words[i].flags) {
  94                                         param->flags |= words[i].flags;
  95                                 } else {
  96                                         param->cmd = words[i].cmd;
  97                                         got_cmd = 1;
  98                                 }
  99                                 break;
 100                         }
 101                 }
 102
 103                 /* On to the next word, if any */
 104                 while (buf[offset] && !isspace(buf[offset]))
 105                         offset++;
 106         }
 107
 108         if (!got_cmd) {
 109                 count = -EINVAL;
 110                 goto exit;
 111         }
 112
 113         msg->version = 0;
 114         msg->command = EC_CMD_REBOOT_EC + ec->cmd_offset;
 115         msg->outsize = sizeof(*param);
 116         msg->insize = 0;
 117         ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 118         if (ret < 0) {
 119                 count = ret;
 120                 goto exit;
 121         }
 122         if (msg->result != EC_RES_SUCCESS) {
 123                 dev_dbg(ec->dev, "EC result %d\n", msg->result);
 124                 count = -EINVAL;
 125         }
 126 exit:
 127         kfree(msg);
 128         return count;
 129 }
 130
 131 static ssize_t show_ec_version(struct device *dev,
 132                                struct device_attribute *attr, char *buf)
 133 {
 134         static const char * const image_names[] = {"unknown", "RO", "RW"};
 135         struct ec_response_get_version *r_ver;
 136         struct ec_response_get_chip_info *r_chip;
 137         struct ec_response_board_version *r_board;
 138         struct cros_ec_command *msg;
 139         int ret;
 140         int count = 0;
 141         struct cros_ec_dev *ec = container_of(dev,
 142                                               struct cros_ec_dev, class_dev);
 143
 144         msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
 145         if (!msg)
 146                 return -ENOMEM;
 147
 148         /* Get versions. RW may change. */
 149         msg->version = 0;
 150         msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
 151         msg->insize = sizeof(*r_ver);
 152         msg->outsize = 0;
 153         ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 154         if (ret < 0) {
 155                 count = ret;
 156                 goto exit;
 157         }
 158         if (msg->result != EC_RES_SUCCESS) {
 159                 count = scnprintf(buf, PAGE_SIZE,
 160                                   "ERROR: EC returned %d\n", msg->result);
 161                 goto exit;
 162         }
 163
 164         r_ver = (struct ec_response_get_version *)msg->data;
 165         /* Strings should be null-terminated, but let's be sure. */
 166         r_ver->version_string_ro[sizeof(r_ver->version_string_ro) - 1] = '\0';
 167         r_ver->version_string_rw[sizeof(r_ver->version_string_rw) - 1] = '\0';
 168         count += scnprintf(buf + count, PAGE_SIZE - count,
 169                            "RO version:    %s\n", r_ver->version_string_ro);
 170         count += scnprintf(buf + count, PAGE_SIZE - count,
 171                            "RW version:    %s\n", r_ver->version_string_rw);
 172         count += scnprintf(buf + count, PAGE_SIZE - count,
 173                            "Firmware copy: %s\n",
 174                            (r_ver->current_image < ARRAY_SIZE(image_names) ?
 175                             image_names[r_ver->current_image] : "?"));
 176
 177         /* Get build info. */
 178         msg->command = EC_CMD_GET_BUILD_INFO + ec->cmd_offset;
 179         msg->insize = EC_HOST_PARAM_SIZE;
 180         ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 181         if (ret < 0)
 182                 count += scnprintf(buf + count, PAGE_SIZE - count,
 183                                    "Build info:    XFER ERROR %d\n", ret);
 184         else if (msg->result != EC_RES_SUCCESS)
 185                 count += scnprintf(buf + count, PAGE_SIZE - count,
 186                                    "Build info:    EC error %d\n", msg->result);
 187         else {
 188                 msg->data[EC_HOST_PARAM_SIZE - 1] = '\0';
 189                 count += scnprintf(buf + count, PAGE_SIZE - count,
 190                                    "Build info:    %s\n", msg->data);
 191         }
 192
 193         /* Get chip info. */
 194         msg->command = EC_CMD_GET_CHIP_INFO + ec->cmd_offset;
 195         msg->insize = sizeof(*r_chip);
 196         ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 197         if (ret < 0)
 198                 count += scnprintf(buf + count, PAGE_SIZE - count,
 199                                    "Chip info:     XFER ERROR %d\n", ret);
 200         else if (msg->result != EC_RES_SUCCESS)
 201                 count += scnprintf(buf + count, PAGE_SIZE - count,
 202                                    "Chip info:     EC error %d\n", msg->result);
 203         else {
 204                 r_chip = (struct ec_response_get_chip_info *)msg->data;
 205
 206                 r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
 207                 r_chip->name[sizeof(r_chip->name) - 1] = '\0';
 208                 r_chip->revision[sizeof(r_chip->revision) - 1] = '\0';
 209                 count += scnprintf(buf + count, PAGE_SIZE - count,
 210                                    "Chip vendor:   %s\n", r_chip->vendor);
 211                 count += scnprintf(buf + count, PAGE_SIZE - count,
 212                                    "Chip name:     %s\n", r_chip->name);
 213                 count += scnprintf(buf + count, PAGE_SIZE - count,
 214                                    "Chip revision: %s\n", r_chip->revision);
 215         }
 216
 217         /* Get board version */
 218         msg->command = EC_CMD_GET_BOARD_VERSION + ec->cmd_offset;
 219         msg->insize = sizeof(*r_board);
 220         ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 221         if (ret < 0)
 222                 count += scnprintf(buf + count, PAGE_SIZE - count,
 223                                    "Board version: XFER ERROR %d\n", ret);
 224         else if (msg->result != EC_RES_SUCCESS)
 225                 count += scnprintf(buf + count, PAGE_SIZE - count,
 226                                    "Board version: EC error %d\n", msg->result);
 227         else {
 228                 r_board = (struct ec_response_board_version *)msg->data;
 229
 230                 count += scnprintf(buf + count, PAGE_SIZE - count,
 231                                    "Board version: %d\n",
 232                                    r_board->board_version);
 233         }
 234
 235 exit:
 236         kfree(msg);
 237         return count;
 238 }
 239
 240 static ssize_t show_ec_flashinfo(struct device *dev,
 241                                  struct device_attribute *attr, char *buf)
 242 {
 243         struct ec_response_flash_info *resp;
 244         struct cros_ec_command *msg;
 245         int ret;
 246         struct cros_ec_dev *ec = container_of(dev,
 247                                               struct cros_ec_dev, class_dev);
 248
 249         msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
 250         if (!msg)
 251                 return -ENOMEM;
 252
 253         /* The flash info shouldn't ever change, but ask each time anyway. */
 254         msg->version = 0;
 255         msg->command = EC_CMD_FLASH_INFO + ec->cmd_offset;
 256         msg->insize = sizeof(*resp);
 257         msg->outsize = 0;
 258         ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 259         if (ret < 0)
 260                 goto exit;
 261         if (msg->result != EC_RES_SUCCESS) {
 262                 ret = scnprintf(buf, PAGE_SIZE,
 263                                 "ERROR: EC returned %d\n", msg->result);
 264                 goto exit;
 265         }
 266
 267         resp = (struct ec_response_flash_info *)msg->data;
 268
 269         ret = scnprintf(buf, PAGE_SIZE,
 270                         "FlashSize %d\nWriteSize %d\n"
 271                         "EraseSize %d\nProtectSize %d\n",
 272                         resp->flash_size, resp->write_block_size,
 273                         resp->erase_block_size, resp->protect_block_size);
 274 exit:
 275         kfree(msg);
 276         return ret;
 277 }
 278
 279 /* Module initialization */
 280
 281 static DEVICE_ATTR(reboot, S_IWUSR | S_IRUGO, show_ec_reboot, store_ec_reboot);
 282 static DEVICE_ATTR(version, S_IRUGO, show_ec_version, NULL);
 283 static DEVICE_ATTR(flashinfo, S_IRUGO, show_ec_flashinfo, NULL);
 284
 285 static struct attribute *__ec_attrs[] = {
 286         &dev_attr_reboot.attr,
 287         &dev_attr_version.attr,
 288         &dev_attr_flashinfo.attr,
 289         NULL,
 290 };
 291
 292 struct attribute_group cros_ec_attr_group = {
 293         .attrs = __ec_attrs,
 294 };
 295 EXPORT_SYMBOL(cros_ec_attr_group);
 296
 297 MODULE_LICENSE("GPL");
 298 MODULE_DESCRIPTION("ChromeOS EC control driver");