]> err.no Git - linux-2.6/blobdiff - drivers/w1/w1.c
[PATCH] pipe: remove redundant fifo_poll abstraction
[linux-2.6] / drivers / w1 / w1.c
index 5b49c9a937f0df4c3a357dfb43549b0ae782821a..0bbf029b1ef1658f99b537fa690a10186275b486 100644 (file)
@@ -59,6 +59,19 @@ static pid_t control_thread;
 static int control_needs_exit;
 static DECLARE_COMPLETION(w1_control_complete);
 
+/* stuff for the default family */
+static ssize_t w1_famdefault_read_name(struct device *dev, struct device_attribute *attr, char *buf)
+{
+       struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+       return(sprintf(buf, "%s\n", sl->name));
+}
+static struct w1_family_ops w1_default_fops = {
+       .rname = &w1_famdefault_read_name,
+};
+static struct w1_family w1_default_family = {
+       .fops = &w1_default_fops,
+};
+
 static int w1_master_match(struct device *dev, struct device_driver *drv)
 {
        return 1;
@@ -102,9 +115,6 @@ static ssize_t w1_default_read_bin(struct kobject *kobj, char *buf, loff_t off,
 static struct device_attribute w1_slave_attribute =
        __ATTR(name, S_IRUGO, w1_default_read_name, NULL);
 
-static struct device_attribute w1_slave_attribute_val =
-       __ATTR(value, S_IRUGO, w1_default_read_name, NULL);
-
 static struct bin_attribute w1_slave_bin_attribute = {
        .attr = {
                .name = "w1_slave",
@@ -138,7 +148,7 @@ struct device w1_device = {
 
 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
 {
-       struct w1_master *md = container_of (dev, struct w1_master, dev);
+       struct w1_master *md = container_of(dev, struct w1_master, dev);
        ssize_t count;
 
        if (down_interruptible (&md->mutex))
@@ -151,6 +161,39 @@ static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_a
        return count;
 }
 
+static ssize_t w1_master_attribute_store_search(struct device * dev,
+                                               struct device_attribute *attr,
+                                               const char * buf, size_t count)
+{
+       struct w1_master *md = container_of(dev, struct w1_master, dev);
+
+       if (down_interruptible (&md->mutex))
+               return -EBUSY;
+
+       md->search_count = simple_strtol(buf, NULL, 0);
+
+       up(&md->mutex);
+
+       return count;
+}
+
+static ssize_t w1_master_attribute_show_search(struct device *dev,
+                                              struct device_attribute *attr,
+                                              char *buf)
+{
+       struct w1_master *md = container_of(dev, struct w1_master, dev);
+       ssize_t count;
+
+       if (down_interruptible (&md->mutex))
+               return -EBUSY;
+
+       count = sprintf(buf, "%d\n", md->search_count);
+
+       up(&md->mutex);
+
+       return count;
+}
+
 static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
 {
        struct w1_master *md = container_of(dev, struct w1_master, dev);
@@ -215,7 +258,6 @@ static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct d
 }
 
 static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf)
-
 {
        struct w1_master *md = container_of(dev, struct w1_master, dev);
        int c = PAGE_SIZE;
@@ -246,6 +288,12 @@ static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device
                __ATTR(w1_master_##_name, _mode,                \
                       w1_master_attribute_show_##_name, NULL)
 
+#define W1_MASTER_ATTR_RW(_name, _mode)                                \
+       struct device_attribute w1_master_attribute_##_name =   \
+               __ATTR(w1_master_##_name, _mode,                \
+                      w1_master_attribute_show_##_name,        \
+                      w1_master_attribute_store_##_name)
+
 static W1_MASTER_ATTR_RO(name, S_IRUGO);
 static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
 static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
@@ -253,6 +301,7 @@ static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
 static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
 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 struct attribute *w1_master_default_attrs[] = {
        &w1_master_attribute_name.attr,
@@ -262,6 +311,7 @@ static struct attribute *w1_master_default_attrs[] = {
        &w1_master_attribute_attempts.attr,
        &w1_master_attribute_timeout.attr,
        &w1_master_attribute_pointer.attr,
+       &w1_master_attribute_search.attr,
        NULL
 };
 
@@ -289,13 +339,13 @@ static int __w1_attach_slave_device(struct w1_slave *sl)
        sl->dev.release = &w1_slave_release;
 
        snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
-                 "%02x-%012llx",
-                 (unsigned int) sl->reg_num.family,
-                 (unsigned long long) sl->reg_num.id);
-       snprintf (&sl->name[0], sizeof(sl->name),
-                 "%02x-%012llx",
-                 (unsigned int) sl->reg_num.family,
-                 (unsigned long long) sl->reg_num.id);
+                "%02x-%012llx",
+                (unsigned int) sl->reg_num.family,
+                (unsigned long long) sl->reg_num.id);
+       snprintf(&sl->name[0], sizeof(sl->name),
+                "%02x-%012llx",
+                (unsigned int) sl->reg_num.family,
+                (unsigned long long) sl->reg_num.id);
 
        dev_dbg(&sl->dev, "%s: registering %s.\n", __func__,
                &sl->dev.bus_id[0]);
@@ -303,48 +353,36 @@ static int __w1_attach_slave_device(struct w1_slave *sl)
        err = device_register(&sl->dev);
        if (err < 0) {
                dev_err(&sl->dev,
-                        "Device registration [%s] failed. err=%d\n",
-                        sl->dev.bus_id, err);
+                       "Device registration [%s] failed. err=%d\n",
+                       sl->dev.bus_id, err);
                return err;
        }
 
        memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin));
        memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name));
-       memcpy(&sl->attr_val, &w1_slave_attribute_val, sizeof(sl->attr_val));
 
        sl->attr_bin.read = sl->family->fops->rbin;
        sl->attr_name.show = sl->family->fops->rname;
-       sl->attr_val.show = sl->family->fops->rval;
-       sl->attr_val.attr.name = sl->family->fops->rvalname;
 
        err = device_create_file(&sl->dev, &sl->attr_name);
        if (err < 0) {
                dev_err(&sl->dev,
-                        "sysfs file creation for [%s] failed. err=%d\n",
-                        sl->dev.bus_id, err);
+                       "sysfs file creation for [%s] failed. err=%d\n",
+                       sl->dev.bus_id, err);
                device_unregister(&sl->dev);
                return err;
        }
 
-       err = device_create_file(&sl->dev, &sl->attr_val);
-       if (err < 0) {
-               dev_err(&sl->dev,
-                        "sysfs file creation for [%s] failed. err=%d\n",
-                        sl->dev.bus_id, err);
-               device_remove_file(&sl->dev, &sl->attr_name);
-               device_unregister(&sl->dev);
-               return err;
-       }
-
-       err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin);
-       if (err < 0) {
-               dev_err(&sl->dev,
-                        "sysfs file creation for [%s] failed. err=%d\n",
-                        sl->dev.bus_id, err);
-               device_remove_file(&sl->dev, &sl->attr_name);
-               device_remove_file(&sl->dev, &sl->attr_val);
-               device_unregister(&sl->dev);
-               return err;
+       if ( sl->attr_bin.read ) {
+               err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin);
+               if (err < 0) {
+                       dev_err(&sl->dev,
+                               "sysfs file creation for [%s] failed. err=%d\n",
+                               sl->dev.bus_id, err);
+                       device_remove_file(&sl->dev, &sl->attr_name);
+                       device_unregister(&sl->dev);
+                       return err;
+               }
        }
 
        list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
@@ -380,12 +418,10 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
        spin_lock(&w1_flock);
        f = w1_family_registered(rn->family);
        if (!f) {
-               spin_unlock(&w1_flock);
+               f= &w1_default_family;
                dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
                          rn->family, rn->family,
                          (unsigned long long)rn->id, rn->crc);
-               kfree(sl);
-               return -ENODEV;
        }
        __w1_family_get(f);
        spin_unlock(&w1_flock);
@@ -426,12 +462,15 @@ static void w1_slave_detach(struct w1_slave *sl)
                        flush_signals(current);
        }
 
-       sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin);
+       if ( sl->attr_bin.read ) {
+               sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin);
+       }
        device_remove_file(&sl->dev, &sl->attr_name);
-       device_remove_file(&sl->dev, &sl->attr_val);
        device_unregister(&sl->dev);
        w1_family_put(sl->family);
 
+       sl->master->slave_count--;
+
        memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id));
        msg.type = W1_SLAVE_REMOVE;
        w1_netlink_send(sl->master, &msg);
@@ -455,6 +494,20 @@ static struct w1_master *w1_search_master(unsigned long data)
        return (found)?dev:NULL;
 }
 
+void w1_reconnect_slaves(struct w1_family *f)
+{
+       struct w1_master *dev;
+
+       spin_lock_bh(&w1_mlock);
+       list_for_each_entry(dev, &w1_masters, w1_master_entry) {
+               dev_info(&dev->dev, "Reconnecting slaves in %s into new family %02x.\n",
+                               dev->name, f->fid);
+               set_bit(W1_MASTER_NEED_RECONNECT, &dev->flags);
+       }
+       spin_unlock_bh(&w1_mlock);
+}
+
+
 static void w1_slave_found(unsigned long data, u64 rn)
 {
        int slave_count;
@@ -463,6 +516,7 @@ static void w1_slave_found(unsigned long data, u64 rn)
        struct w1_reg_num *tmp;
        int family_found = 0;
        struct w1_master *dev;
+       u64 rn_le = cpu_to_le64(rn);
 
        dev = w1_search_master(data);
        if (!dev) {
@@ -491,36 +545,47 @@ static void w1_slave_found(unsigned long data, u64 rn)
                slave_count++;
        }
 
-       rn = cpu_to_le64(rn);
-
        if (slave_count == dev->slave_count &&
-               rn && ((le64_to_cpu(rn) >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) {
+               rn && ((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn_le, 7)) {
                w1_attach_slave_device(dev, tmp);
        }
 
        atomic_dec(&dev->refcnt);
 }
 
-void w1_search(struct w1_master *dev)
+/**
+ * Performs a ROM Search & registers any devices found.
+ * The 1-wire search is a simple binary tree search.
+ * For each bit of the address, we read two bits and write one bit.
+ * The bit written will put to sleep all devies that don't match that bit.
+ * When the two reads differ, the direction choice is obvious.
+ * When both bits are 0, we must choose a path to take.
+ * When we can scan all 64 bits without having to choose a path, we are done.
+ *
+ * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
+ *
+ * @dev        The master device to search
+ * @cb         Function to call when a device is found
+ */
+void w1_search(struct w1_master *dev, w1_slave_found_callback cb)
 {
-       u64 last, rn, tmp;
-       int i, count = 0;
-       int last_family_desc, last_zero, last_device;
-       int search_bit, id_bit, comp_bit, desc_bit;
+       u64 last_rn, rn, tmp64;
+       int i, slave_count = 0;
+       int last_zero, last_device;
+       int search_bit, desc_bit;
+       u8  triplet_ret = 0;
 
-       search_bit = id_bit = comp_bit = 0;
-       rn = tmp = last = 0;
-       last_device = last_zero = last_family_desc = 0;
+       search_bit = 0;
+       rn = last_rn = 0;
+       last_device = 0;
+       last_zero = -1;
 
        desc_bit = 64;
 
-       while (!(id_bit && comp_bit) && !last_device &&
-              count++ < dev->max_slave_count) {
-               last = rn;
+       while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
+               last_rn = rn;
                rn = 0;
 
-               last_family_desc = 0;
-
                /*
                 * Reset bus and all 1-wire device state machines
                 * so they can respond to our requests.
@@ -528,63 +593,43 @@ void w1_search(struct w1_master *dev)
                 * Return 0 - device(s) present, 1 - no devices present.
                 */
                if (w1_reset_bus(dev)) {
-                       dev_info(&dev->dev, "No devices present on the wire.\n");
+                       dev_dbg(&dev->dev, "No devices present on the wire.\n");
                        break;
                }
 
-#if 1
+               /* Start the search */
                w1_write_8(dev, W1_SEARCH);
                for (i = 0; i < 64; ++i) {
-                       /*
-                        * Read 2 bits from bus.
-                        * All who don't sleep must send ID bit and COMPLEMENT ID bit.
-                        * They actually are ANDed between all senders.
-                        */
-                       id_bit = w1_touch_bit(dev, 1);
-                       comp_bit = w1_touch_bit(dev, 1);
-
-                       if (id_bit && comp_bit)
-                               break;
-
-                       if (id_bit == 0 && comp_bit == 0) {
-                               if (i == desc_bit)
-                                       search_bit = 1;
-                               else if (i > desc_bit)
-                                       search_bit = 0;
-                               else
-                                       search_bit = ((last >> i) & 0x1);
-
-                               if (search_bit == 0) {
-                                       last_zero = i;
-                                       if (last_zero < 9)
-                                               last_family_desc = last_zero;
-                               }
+                       /* Determine the direction/search bit */
+                       if (i == desc_bit)
+                               search_bit = 1;   /* took the 0 path last time, so take the 1 path */
+                       else if (i > desc_bit)
+                               search_bit = 0;   /* take the 0 path on the next branch */
+                       else
+                               search_bit = ((last_rn >> i) & 0x1);
 
-                       } else
-                               search_bit = id_bit;
+                       /** Read two bits and write one bit */
+                       triplet_ret = w1_triplet(dev, search_bit);
 
-                       tmp = search_bit;
-                       rn |= (tmp << i);
+                       /* quit if no device responded */
+                       if ( (triplet_ret & 0x03) == 0x03 )
+                               break;
 
-                       /*
-                        * Write 1 bit to bus
-                        * and make all who don't have "search_bit" in "i"'th position
-                        * in it's registration number sleep.
-                        */
-                       if (dev->bus_master->touch_bit)
-                               w1_touch_bit(dev, search_bit);
-                       else
-                               w1_write_bit(dev, search_bit);
+                       /* If both directions were valid, and we took the 0 path... */
+                       if (triplet_ret == 0)
+                               last_zero = i;
 
+                       /* extract the direction taken & update the device number */
+                       tmp64 = (triplet_ret >> 2);
+                       rn |= (tmp64 << i);
                }
-#endif
-
-               if (desc_bit == last_zero)
-                       last_device = 1;
-
-               desc_bit = last_zero;
 
-               w1_slave_found(dev->bus_master->data, rn);
+               if ( (triplet_ret & 0x03) != 0x03 ) {
+                       if ( (desc_bit == last_zero) || (last_zero < 0))
+                               last_device = 1;
+                       desc_bit = last_zero;
+                       cb(dev->bus_master->data, rn);
+               }
        }
 }
 
@@ -600,14 +645,14 @@ static int w1_control(void *data)
        while (!control_needs_exit || have_to_wait) {
                have_to_wait = 0;
 
-               try_to_freeze(PF_FREEZE);
+               try_to_freeze();
                msleep_interruptible(w1_timeout * 1000);
 
                if (signal_pending(current))
                        flush_signals(current);
 
                list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) {
-                       if (!control_needs_exit && !dev->need_exit)
+                       if (!control_needs_exit && !dev->flags)
                                continue;
                        /*
                         * Little race: we can create thread but not set the flag.
@@ -618,12 +663,8 @@ static int w1_control(void *data)
                                continue;
                        }
 
-                       spin_lock_bh(&w1_mlock);
-                       list_del(&dev->w1_master_entry);
-                       spin_unlock_bh(&w1_mlock);
-
                        if (control_needs_exit) {
-                               dev->need_exit = 1;
+                               set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
 
                                err = kill_proc(dev->kpid, SIGTERM, 1);
                                if (err)
@@ -632,16 +673,42 @@ static int w1_control(void *data)
                                                 dev->kpid);
                        }
 
-                       wait_for_completion(&dev->dev_exited);
+                       if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
+                               wait_for_completion(&dev->dev_exited);
+                               spin_lock_bh(&w1_mlock);
+                               list_del(&dev->w1_master_entry);
+                               spin_unlock_bh(&w1_mlock);
 
-                       list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
-                               list_del(&sl->w1_slave_entry);
+                               list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
+                                       list_del(&sl->w1_slave_entry);
 
-                               w1_slave_detach(sl);
-                               kfree(sl);
+                                       w1_slave_detach(sl);
+                                       kfree(sl);
+                               }
+                               w1_destroy_master_attributes(dev);
+                               atomic_dec(&dev->refcnt);
+                               continue;
+                       }
+
+                       if (test_bit(W1_MASTER_NEED_RECONNECT, &dev->flags)) {
+                               dev_info(&dev->dev, "Reconnecting slaves in device %s.\n", dev->name);
+                               down(&dev->mutex);
+                               list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
+                                       if (sl->family->fid == W1_FAMILY_DEFAULT) {
+                                               struct w1_reg_num rn;
+                                               list_del(&sl->w1_slave_entry);
+                                               w1_slave_detach(sl);
+
+                                               memcpy(&rn, &sl->reg_num, sizeof(rn));
+
+                                               kfree(sl);
+
+                                               w1_attach_slave_device(dev, &rn);
+                                       }
+                               }
+                               clear_bit(W1_MASTER_NEED_RECONNECT, &dev->flags);
+                               up(&dev->mutex);
                        }
-                       w1_destroy_master_attributes(dev);
-                       atomic_dec(&dev->refcnt);
                }
        }
 
@@ -656,24 +723,27 @@ int w1_process(void *data)
        daemonize("%s", dev->name);
        allow_signal(SIGTERM);
 
-       while (!dev->need_exit) {
-               try_to_freeze(PF_FREEZE);
+       while (!test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
+               try_to_freeze();
                msleep_interruptible(w1_timeout * 1000);
 
                if (signal_pending(current))
                        flush_signals(current);
 
-               if (dev->need_exit)
+               if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags))
                        break;
 
                if (!dev->initialized)
                        continue;
 
+               if (dev->search_count == 0)
+                       continue;
+
                if (down_interruptible(&dev->mutex))
                        continue;
 
                list_for_each_entry(sl, &dev->slist, w1_slave_entry)
-                               clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
+                       clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 
                w1_search_devices(dev, w1_slave_found);
 
@@ -688,6 +758,10 @@ int w1_process(void *data)
                        } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
                                sl->ttl = dev->slave_ttl;
                }
+
+               if (dev->search_count > 0)
+                       dev->search_count--;
+
                up(&dev->mutex);
        }