diff options
Diffstat (limited to 'drivers/w1/w1_int.c')
| -rw-r--r-- | drivers/w1/w1_int.c | 88 |
1 files changed, 72 insertions, 16 deletions
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c index 6840dfebe4d..a3a54567bfb 100644 --- a/drivers/w1/w1_int.c +++ b/drivers/w1/w1_int.c @@ -29,7 +29,11 @@ #include "w1_netlink.h" #include "w1_int.h" -static u32 w1_ids = 1; +static int w1_search_count = -1; /* Default is continual scan */ +module_param_named(search_count, w1_search_count, int, 0); + +static int w1_enable_pullup = 1; +module_param_named(enable_pullup, w1_enable_pullup, int, 0); static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl, struct device_driver *driver, @@ -59,8 +63,12 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl, dev->initialized = 0; dev->id = id; dev->slave_ttl = slave_ttl; - dev->search_count = -1; /* continual scan */ + dev->search_count = w1_search_count; + dev->enable_pullup = w1_enable_pullup; + /* 1 for w1_process to decrement + * 1 for __w1_remove_master_device to decrement + */ atomic_set(&dev->refcnt, 2); INIT_LIST_HEAD(&dev->slist); @@ -93,9 +101,10 @@ static void w1_free_dev(struct w1_master *dev) int w1_add_master_device(struct w1_bus_master *master) { - struct w1_master *dev; + struct w1_master *dev, *entry; int retval = 0; struct w1_netlink_msg msg; + int id, found; /* validate minimum functionality */ if (!(master->touch_bit && master->reset_bus) && @@ -104,10 +113,50 @@ int w1_add_master_device(struct w1_bus_master *master) printk(KERN_ERR "w1_add_master_device: invalid function set\n"); return(-EINVAL); } + /* While it would be electrically possible to make a device that + * generated a strong pullup in bit bang mode, only hardare that + * controls 1-wire time frames are even expected to support a strong + * pullup. w1_io.c would need to support calling set_pullup before + * the last write_bit operation of a w1_write_8 which it currently + * doesn't. + */ + if (!master->write_byte && !master->touch_bit && master->set_pullup) { + printk(KERN_ERR "w1_add_master_device: set_pullup requires " + "write_byte or touch_bit, disabling\n"); + master->set_pullup = NULL; + } + + /* Lock until the device is added (or not) to w1_masters. */ + mutex_lock(&w1_mlock); + /* Search for the first available id (starting at 1). */ + id = 0; + do { + ++id; + found = 0; + list_for_each_entry(entry, &w1_masters, w1_master_entry) { + if (entry->id == id) { + found = 1; + break; + } + } + } while (found); - dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_master_driver, &w1_master_device); - if (!dev) + dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl, + &w1_master_driver, &w1_master_device); + if (!dev) { + mutex_unlock(&w1_mlock); return -ENOMEM; + } + + retval = w1_create_master_attributes(dev); + if (retval) { + mutex_unlock(&w1_mlock); + goto err_out_free_dev; + } + + memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); + + dev->initialized = 1; dev->thread = kthread_run(&w1_process, dev, "%s", dev->name); if (IS_ERR(dev->thread)) { @@ -115,18 +164,10 @@ int w1_add_master_device(struct w1_bus_master *master) dev_err(&dev->dev, "Failed to create new kernel thread. err=%d\n", retval); - goto err_out_free_dev; + mutex_unlock(&w1_mlock); + goto err_out_rm_attr; } - retval = w1_create_master_attributes(dev); - if (retval) - goto err_out_kill_thread; - - memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); - - dev->initialized = 1; - - mutex_lock(&w1_mlock); list_add(&dev->w1_master_entry, &w1_masters); mutex_unlock(&w1_mlock); @@ -137,8 +178,12 @@ int w1_add_master_device(struct w1_bus_master *master) return 0; +#if 0 /* Thread cleanup code, not required currently. */ err_out_kill_thread: kthread_stop(dev->thread); +#endif +err_out_rm_attr: + w1_destroy_master_attributes(dev); err_out_free_dev: w1_free_dev(dev); @@ -148,10 +193,21 @@ err_out_free_dev: void __w1_remove_master_device(struct w1_master *dev) { struct w1_netlink_msg msg; + struct w1_slave *sl, *sln; - set_bit(W1_MASTER_NEED_EXIT, &dev->flags); kthread_stop(dev->thread); + mutex_lock(&w1_mlock); + list_del(&dev->w1_master_entry); + mutex_unlock(&w1_mlock); + + mutex_lock(&dev->mutex); + list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) + w1_slave_detach(sl); + w1_destroy_master_attributes(dev); + mutex_unlock(&dev->mutex); + atomic_dec(&dev->refcnt); + while (atomic_read(&dev->refcnt)) { dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n", dev->name, atomic_read(&dev->refcnt)); |