target/linux/ipq806x/patches-4.4/009-4-watchdog-Read-device-status-through-sysfs-attributes.patch

   1 From 33b711269ade3f6bc9d9d15e4343e6fa922d999b Mon Sep 17 00:00:00 2001
   2 From: Pratyush Anand <panand@redhat.com>
   3 Date: Thu, 17 Dec 2015 17:53:59 +0530
   4 Subject: watchdog: Read device status through sysfs attributes
   5
   6 This patch adds following attributes to watchdog device's sysfs interface
   7 to read its different status.
   8
   9 * state - reads whether device is active or not
  10 * identity - reads Watchdog device's identity string.
  11 * timeout - reads current timeout.
  12 * timeleft - reads timeleft before watchdog generates a reset
  13 * bootstatus - reads status of the watchdog device at boot
  14 * status - reads watchdog device's  internal status bits
  15 * nowayout - reads whether nowayout feature was set or not
  16
  17 Testing with iTCO_wdt:
  18  # cd /sys/class/watchdog/watchdog1/
  19  # ls
  20 bootstatus  dev  device  identity  nowayout  power  state
  21 subsystem  timeleft  timeout  uevent
  22  # cat identity
  23 iTCO_wdt
  24  # cat timeout
  25 30
  26  # cat state
  27 inactive
  28  # echo > /dev/watchdog1
  29  # cat timeleft
  30 26
  31  # cat state
  32 active
  33  # cat bootstatus
  34 0
  35  # cat nowayout
  36 0
  37
  38 Signed-off-by: Pratyush Anand <panand@redhat.com>
  39 Reviewed-by: Guenter Roeck <linux@roeck-us.net>
  40 Signed-off-by: Guenter Roeck <linux@roeck-us.net>
  41 Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
  42 ---
  43  Documentation/ABI/testing/sysfs-class-watchdog |  51 +++++++++++
  44  drivers/watchdog/Kconfig                       |   7 ++
  45  drivers/watchdog/watchdog_core.c               |   2 +-
  46  drivers/watchdog/watchdog_dev.c                | 114 +++++++++++++++++++++++++
  47  4 files changed, 173 insertions(+), 1 deletion(-)
  48  create mode 100644 Documentation/ABI/testing/sysfs-class-watchdog
  49
  50 --- /dev/null
  51 +++ b/Documentation/ABI/testing/sysfs-class-watchdog
  52 @@ -0,0 +1,51 @@
  53 +What:          /sys/class/watchdog/watchdogn/bootstatus
  54 +Date:          August 2015
  55 +Contact:       Wim Van Sebroeck <wim@iguana.be>
  56 +Description:
  57 +               It is a read only file. It contains status of the watchdog
  58 +               device at boot. It is equivalent to WDIOC_GETBOOTSTATUS of
  59 +               ioctl interface.
  60 +
  61 +What:          /sys/class/watchdog/watchdogn/identity
  62 +Date:          August 2015
  63 +Contact:       Wim Van Sebroeck <wim@iguana.be>
  64 +Description:
  65 +               It is a read only file. It contains identity string of
  66 +               watchdog device.
  67 +
  68 +What:          /sys/class/watchdog/watchdogn/nowayout
  69 +Date:          August 2015
  70 +Contact:       Wim Van Sebroeck <wim@iguana.be>
  71 +Description:
  72 +               It is a read only file. While reading, it gives '1' if that
  73 +               device supports nowayout feature else, it gives '0'.
  74 +
  75 +What:          /sys/class/watchdog/watchdogn/state
  76 +Date:          August 2015
  77 +Contact:       Wim Van Sebroeck <wim@iguana.be>
  78 +Description:
  79 +               It is a read only file. It gives active/inactive status of
  80 +               watchdog device.
  81 +
  82 +What:          /sys/class/watchdog/watchdogn/status
  83 +Date:          August 2015
  84 +Contact:       Wim Van Sebroeck <wim@iguana.be>
  85 +Description:
  86 +               It is a read only file. It contains watchdog device's
  87 +               internal status bits. It is equivalent to WDIOC_GETSTATUS
  88 +               of ioctl interface.
  89 +
  90 +What:          /sys/class/watchdog/watchdogn/timeleft
  91 +Date:          August 2015
  92 +Contact:       Wim Van Sebroeck <wim@iguana.be>
  93 +Description:
  94 +               It is a read only file. It contains value of time left for
  95 +               reset generation. It is equivalent to WDIOC_GETTIMELEFT of
  96 +               ioctl interface.
  97 +
  98 +What:          /sys/class/watchdog/watchdogn/timeout
  99 +Date:          August 2015
 100 +Contact:       Wim Van Sebroeck <wim@iguana.be>
 101 +Description:
 102 +               It is a read only file. It is read to know about current
 103 +               value of timeout programmed.
 104 --- a/drivers/watchdog/Kconfig
 105 +++ b/drivers/watchdog/Kconfig
 106 @@ -46,6 +46,13 @@ config WATCHDOG_NOWAYOUT
 107           get killed. If you say Y here, the watchdog cannot be stopped once
 108           it has been started.
 109
 110 +config WATCHDOG_SYSFS
 111 +       bool "Read different watchdog information through sysfs"
 112 +       default n
 113 +       help
 114 +         Say Y here if you want to enable watchdog device status read through
 115 +         sysfs attributes.
 116 +
 117  #
 118  # General Watchdog drivers
 119  #
 120 --- a/drivers/watchdog/watchdog_core.c
 121 +++ b/drivers/watchdog/watchdog_core.c
 122 @@ -249,7 +249,7 @@ static int __watchdog_register_device(st
 123
 124         devno = wdd->cdev.dev;
 125         wdd->dev = device_create(watchdog_class, wdd->parent, devno,
 126 -                                       NULL, "watchdog%d", wdd->id);
 127 +                                       wdd, "watchdog%d", wdd->id);
 128         if (IS_ERR(wdd->dev)) {
 129                 watchdog_dev_unregister(wdd);
 130                 ida_simple_remove(&watchdog_ida, id);
 131 --- a/drivers/watchdog/watchdog_dev.c
 132 +++ b/drivers/watchdog/watchdog_dev.c
 133 @@ -247,6 +247,119 @@ out_timeleft:
 134         return err;
 135  }
 136
 137 +#ifdef CONFIG_WATCHDOG_SYSFS
 138 +static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr,
 139 +                               char *buf)
 140 +{
 141 +       struct watchdog_device *wdd = dev_get_drvdata(dev);
 142 +
 143 +       return sprintf(buf, "%d\n", !!test_bit(WDOG_NO_WAY_OUT, &wdd->status));
 144 +}
 145 +static DEVICE_ATTR_RO(nowayout);
 146 +
 147 +static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 148 +                               char *buf)
 149 +{
 150 +       struct watchdog_device *wdd = dev_get_drvdata(dev);
 151 +       ssize_t status;
 152 +       unsigned int val;
 153 +
 154 +       status = watchdog_get_status(wdd, &val);
 155 +       if (!status)
 156 +               status = sprintf(buf, "%u\n", val);
 157 +
 158 +       return status;
 159 +}
 160 +static DEVICE_ATTR_RO(status);
 161 +
 162 +static ssize_t bootstatus_show(struct device *dev,
 163 +                               struct device_attribute *attr, char *buf)
 164 +{
 165 +       struct watchdog_device *wdd = dev_get_drvdata(dev);
 166 +
 167 +       return sprintf(buf, "%u\n", wdd->bootstatus);
 168 +}
 169 +static DEVICE_ATTR_RO(bootstatus);
 170 +
 171 +static ssize_t timeleft_show(struct device *dev, struct device_attribute *attr,
 172 +                               char *buf)
 173 +{
 174 +       struct watchdog_device *wdd = dev_get_drvdata(dev);
 175 +       ssize_t status;
 176 +       unsigned int val;
 177 +
 178 +       status = watchdog_get_timeleft(wdd, &val);
 179 +       if (!status)
 180 +               status = sprintf(buf, "%u\n", val);
 181 +
 182 +       return status;
 183 +}
 184 +static DEVICE_ATTR_RO(timeleft);
 185 +
 186 +static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
 187 +                               char *buf)
 188 +{
 189 +       struct watchdog_device *wdd = dev_get_drvdata(dev);
 190 +
 191 +       return sprintf(buf, "%u\n", wdd->timeout);
 192 +}
 193 +static DEVICE_ATTR_RO(timeout);
 194 +
 195 +static ssize_t identity_show(struct device *dev, struct device_attribute *attr,
 196 +                               char *buf)
 197 +{
 198 +       struct watchdog_device *wdd = dev_get_drvdata(dev);
 199 +
 200 +       return sprintf(buf, "%s\n", wdd->info->identity);
 201 +}
 202 +static DEVICE_ATTR_RO(identity);
 203 +
 204 +static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 205 +                               char *buf)
 206 +{
 207 +       struct watchdog_device *wdd = dev_get_drvdata(dev);
 208 +
 209 +       if (watchdog_active(wdd))
 210 +               return sprintf(buf, "active\n");
 211 +
 212 +       return sprintf(buf, "inactive\n");
 213 +}
 214 +static DEVICE_ATTR_RO(state);
 215 +
 216 +static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr,
 217 +                               int n)
 218 +{
 219 +       struct device *dev = container_of(kobj, struct device, kobj);
 220 +       struct watchdog_device *wdd = dev_get_drvdata(dev);
 221 +       umode_t mode = attr->mode;
 222 +
 223 +       if (attr == &dev_attr_status.attr && !wdd->ops->status)
 224 +               mode = 0;
 225 +       else if (attr == &dev_attr_timeleft.attr && !wdd->ops->get_timeleft)
 226 +               mode = 0;
 227 +
 228 +       return mode;
 229 +}
 230 +static struct attribute *wdt_attrs[] = {
 231 +       &dev_attr_state.attr,
 232 +       &dev_attr_identity.attr,
 233 +       &dev_attr_timeout.attr,
 234 +       &dev_attr_timeleft.attr,
 235 +       &dev_attr_bootstatus.attr,
 236 +       &dev_attr_status.attr,
 237 +       &dev_attr_nowayout.attr,
 238 +       NULL,
 239 +};
 240 +
 241 +static const struct attribute_group wdt_group = {
 242 +       .attrs = wdt_attrs,
 243 +       .is_visible = wdt_is_visible,
 244 +};
 245 +__ATTRIBUTE_GROUPS(wdt);
 246 +#else
 247 +#define wdt_groups     NULL
 248 +#endif
 249 +
 250  /*
 251   *     watchdog_ioctl_op: call the watchdog drivers ioctl op if defined
 252   *     @wdd: the watchdog device to do the ioctl on
 253 @@ -584,6 +697,7 @@ int watchdog_dev_unregister(struct watch
 254  static struct class watchdog_class = {
 255         .name =         "watchdog",
 256         .owner =        THIS_MODULE,
 257 +       .dev_groups =   wdt_groups,
 258  };
 259
 260  /*