W1: be able to manually add and remove slaves
authorDavid Fries <david@fries.net>
Thu, 16 Oct 2008 05:04:43 +0000 (22:04 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 16 Oct 2008 18:21:49 +0000 (11:21 -0700)
sysfs entries were added to manually add and remove slave devices.  This
is useful if the automatic bus searching is disabled, and the device ids
are already known.

[akpm@linux-foundation.org: fix printk types]
Signed-off-by: David Fries <david@fries.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/w1/w1.c

index 32418d4e555a0add94001c8c8d2a4db8b19308aa..f3be2991e6e8d96cc63dccd6b587f8fdfd641f39 100644 (file)
@@ -56,6 +56,8 @@ module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
 DEFINE_MUTEX(w1_mlock);
 LIST_HEAD(w1_masters);
 
 DEFINE_MUTEX(w1_mlock);
 LIST_HEAD(w1_masters);
 
+static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
+
 static int w1_master_match(struct device *dev, struct device_driver *drv)
 {
        return 1;
 static int w1_master_match(struct device *dev, struct device_driver *drv)
 {
        return 1;
@@ -357,7 +359,8 @@ static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct d
        return count;
 }
 
        return count;
 }
 
-static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf)
+static ssize_t w1_master_attribute_show_slaves(struct device *dev,
+       struct device_attribute *attr, char *buf)
 {
        struct w1_master *md = dev_to_w1_master(dev);
        int c = PAGE_SIZE;
 {
        struct w1_master *md = dev_to_w1_master(dev);
        int c = PAGE_SIZE;
@@ -382,6 +385,135 @@ static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device
        return PAGE_SIZE - c;
 }
 
        return PAGE_SIZE - c;
 }
 
+static ssize_t w1_master_attribute_show_add(struct device *dev,
+       struct device_attribute *attr, char *buf)
+{
+       int c = PAGE_SIZE;
+       c -= snprintf(buf+PAGE_SIZE - c, c,
+               "write device id xx-xxxxxxxxxxxx to add slave\n");
+       return PAGE_SIZE - c;
+}
+
+static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
+       struct w1_reg_num *rn)
+{
+       unsigned int family;
+       unsigned long long id;
+       int i;
+       u64 rn64_le;
+
+       /* The CRC value isn't read from the user because the sysfs directory
+        * doesn't include it and most messages from the bus search don't
+        * print it either.  It would be unreasonable for the user to then
+        * provide it.
+        */
+       const char *error_msg = "bad slave string format, expecting "
+               "ff-dddddddddddd\n";
+
+       if (buf[2] != '-') {
+               dev_err(dev, "%s", error_msg);
+               return -EINVAL;
+       }
+       i = sscanf(buf, "%02x-%012llx", &family, &id);
+       if (i != 2) {
+               dev_err(dev, "%s", error_msg);
+               return -EINVAL;
+       }
+       rn->family = family;
+       rn->id = id;
+
+       rn64_le = cpu_to_le64(*(u64 *)rn);
+       rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
+
+#if 0
+       dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
+                 rn->family, (unsigned long long)rn->id, rn->crc);
+#endif
+
+       return 0;
+}
+
+/* Searches the slaves in the w1_master and returns a pointer or NULL.
+ * Note: must hold the mutex
+ */
+static struct w1_slave *w1_slave_search_device(struct w1_master *dev,
+       struct w1_reg_num *rn)
+{
+       struct w1_slave *sl;
+       list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
+               if (sl->reg_num.family == rn->family &&
+                               sl->reg_num.id == rn->id &&
+                               sl->reg_num.crc == rn->crc) {
+                       return sl;
+               }
+       }
+       return NULL;
+}
+
+static ssize_t w1_master_attribute_store_add(struct device *dev,
+                                               struct device_attribute *attr,
+                                               const char *buf, size_t count)
+{
+       struct w1_master *md = dev_to_w1_master(dev);
+       struct w1_reg_num rn;
+       struct w1_slave *sl;
+       ssize_t result = count;
+
+       if (w1_atoreg_num(dev, buf, count, &rn))
+               return -EINVAL;
+
+       mutex_lock(&md->mutex);
+       sl = w1_slave_search_device(md, &rn);
+       /* It would be nice to do a targeted search one the one-wire bus
+        * for the new device to see if it is out there or not.  But the
+        * current search doesn't support that.
+        */
+       if (sl) {
+               dev_info(dev, "Device %s already exists\n", sl->name);
+               result = -EINVAL;
+       } else {
+               w1_attach_slave_device(md, &rn);
+       }
+       mutex_unlock(&md->mutex);
+
+       return result;
+}
+
+static ssize_t w1_master_attribute_show_remove(struct device *dev,
+       struct device_attribute *attr, char *buf)
+{
+       int c = PAGE_SIZE;
+       c -= snprintf(buf+PAGE_SIZE - c, c,
+               "write device id xx-xxxxxxxxxxxx to remove slave\n");
+       return PAGE_SIZE - c;
+}
+
+static ssize_t w1_master_attribute_store_remove(struct device *dev,
+                                               struct device_attribute *attr,
+                                               const char *buf, size_t count)
+{
+       struct w1_master *md = dev_to_w1_master(dev);
+       struct w1_reg_num rn;
+       struct w1_slave *sl;
+       ssize_t result = count;
+
+       if (w1_atoreg_num(dev, buf, count, &rn))
+               return -EINVAL;
+
+       mutex_lock(&md->mutex);
+       sl = w1_slave_search_device(md, &rn);
+       if (sl) {
+               w1_slave_detach(sl);
+       } else {
+               dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
+                       (unsigned long long)rn.id);
+               result = -EINVAL;
+       }
+       mutex_unlock(&md->mutex);
+
+       return result;
+}
+
 #define W1_MASTER_ATTR_RO(_name, _mode)                                \
        struct device_attribute w1_master_attribute_##_name =   \
                __ATTR(w1_master_##_name, _mode,                \
 #define W1_MASTER_ATTR_RO(_name, _mode)                                \
        struct device_attribute w1_master_attribute_##_name =   \
                __ATTR(w1_master_##_name, _mode,                \
@@ -402,6 +534,8 @@ static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
 static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO);
 static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUGO);
 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
 static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO);
 static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUGO);
+static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUGO);
+static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUGO);
 
 static struct attribute *w1_master_default_attrs[] = {
        &w1_master_attribute_name.attr,
 
 static struct attribute *w1_master_default_attrs[] = {
        &w1_master_attribute_name.attr,
@@ -413,6 +547,8 @@ static struct attribute *w1_master_default_attrs[] = {
        &w1_master_attribute_pointer.attr,
        &w1_master_attribute_search.attr,
        &w1_master_attribute_pullup.attr,
        &w1_master_attribute_pointer.attr,
        &w1_master_attribute_search.attr,
        &w1_master_attribute_pullup.attr,
+       &w1_master_attribute_add.attr,
+       &w1_master_attribute_remove.attr,
        NULL
 };
 
        NULL
 };