diff options
Diffstat (limited to 'drivers/w1')
| -rw-r--r-- | drivers/w1/w1.c | 138 |
1 files changed, 137 insertions, 1 deletions
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index 32418d4e555a..f3be2991e6e8 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -56,6 +56,8 @@ module_param_named(slave_ttl, w1_max_slave_ttl, int, 0); 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; @@ -357,7 +359,8 @@ static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct d 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; @@ -382,6 +385,135 @@ static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device 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, \ @@ -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_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, @@ -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_add.attr, + &w1_master_attribute_remove.attr, NULL }; |