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