diff options
| -rw-r--r-- | Documentation/ABI/stable/sysfs-bus-w1 | 11 | ||||
| -rw-r--r-- | Documentation/w1/w1.generic | 30 | ||||
| -rw-r--r-- | drivers/w1/w1.c | 17 |
3 files changed, 46 insertions, 12 deletions
diff --git a/Documentation/ABI/stable/sysfs-bus-w1 b/Documentation/ABI/stable/sysfs-bus-w1 new file mode 100644 index 000000000000..140d85b4ae92 --- /dev/null +++ b/Documentation/ABI/stable/sysfs-bus-w1 @@ -0,0 +1,11 @@ +What: /sys/bus/w1/devices/.../w1_master_timeout_us +Date: April 2015 +Contact: Dmitry Khromov <dk@icelogic.net> +Description: Bus scanning interval, microseconds component. + Some of 1-Wire devices commonly associated with physical access + control systems are attached/generate presence for as short as + 100 ms - hence the tens-to-hundreds milliseconds scan intervals + are required. + see Documentation/w1/w1.generic for detailed information. +Users: any user space application which wants to know bus scanning + interval diff --git a/Documentation/w1/w1.generic b/Documentation/w1/w1.generic index b2033c64c7da..b3ffaf8cfab2 100644 --- a/Documentation/w1/w1.generic +++ b/Documentation/w1/w1.generic @@ -76,21 +76,24 @@ See struct w1_bus_master definition in w1.h for details. w1 master sysfs interface ------------------------------------------------------------------ -<xx-xxxxxxxxxxxxx> - a directory for a found device. The format is family-serial +<xx-xxxxxxxxxxxxx> - A directory for a found device. The format is family-serial bus - (standard) symlink to the w1 bus driver - (standard) symlink to the w1 driver -w1_master_add - Manually register a slave device -w1_master_attempts - the number of times a search was attempted +w1_master_add - (rw) manually register a slave device +w1_master_attempts - (ro) the number of times a search was attempted w1_master_max_slave_count - - maximum number of slaves to search for at a time -w1_master_name - the name of the device (w1_bus_masterX) -w1_master_pullup - 5V strong pullup 0 enabled, 1 disabled -w1_master_remove - Manually remove a slave device -w1_master_search - the number of searches left to do, -1=continual (default) + - (rw) maximum number of slaves to search for at a time +w1_master_name - (ro) the name of the device (w1_bus_masterX) +w1_master_pullup - (rw) 5V strong pullup 0 enabled, 1 disabled +w1_master_remove - (rw) manually remove a slave device +w1_master_search - (rw) the number of searches left to do, + -1=continual (default) w1_master_slave_count - - the number of slaves found -w1_master_slaves - the names of the slaves, one per line -w1_master_timeout - the delay in seconds between searches + - (ro) the number of slaves found +w1_master_slaves - (ro) the names of the slaves, one per line +w1_master_timeout - (ro) the delay in seconds between searches +w1_master_timeout_us + - (ro) the delay in microseconds beetwen searches If you have a w1 bus that never changes (you don't add or remove devices), you can set the module parameter search_count to a small positive number @@ -101,6 +104,11 @@ generally only make sense when searching is disabled, as a search will redetect manually removed devices that are present and timeout manually added devices that aren't on the bus. +Bus searches occur at an interval, specified as a summ of timeout and +timeout_us module parameters (either of which may be 0) for as long as +w1_master_search remains greater than 0 or is -1. Each search attempt +decrements w1_master_search by 1 (down to 0) and increments +w1_master_attempts by 1. w1 slave sysfs interface ------------------------------------------------------------------ diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index 181f41cb960b..c9a7ff67d395 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -46,11 +46,15 @@ MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol."); static int w1_timeout = 10; +static int w1_timeout_us = 0; int w1_max_slave_count = 64; int w1_max_slave_ttl = 10; module_param_named(timeout, w1_timeout, int, 0); MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches"); +module_param_named(timeout_us, w1_timeout_us, int, 0); +MODULE_PARM_DESC(timeout, "time in microseconds between automatic slave" + " searches"); /* A search stops when w1_max_slave_count devices have been found in that * search. The next search will start over and detect the same set of devices * on a static 1-wire bus. Memory is not allocated based on this number, just @@ -317,6 +321,14 @@ static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct devic return count; } +static ssize_t w1_master_attribute_show_timeout_us(struct device *dev, + struct device_attribute *attr, char *buf) +{ + ssize_t count; + count = sprintf(buf, "%d\n", w1_timeout_us); + return count; +} + static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { @@ -543,6 +555,7 @@ static W1_MASTER_ATTR_RO(slave_count, S_IRUGO); static W1_MASTER_ATTR_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP); static W1_MASTER_ATTR_RO(attempts, S_IRUGO); static W1_MASTER_ATTR_RO(timeout, S_IRUGO); +static W1_MASTER_ATTR_RO(timeout_us, S_IRUGO); static W1_MASTER_ATTR_RO(pointer, S_IRUGO); static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUSR | S_IWGRP); static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP); @@ -556,6 +569,7 @@ static struct attribute *w1_master_default_attrs[] = { &w1_master_attribute_max_slave_count.attr, &w1_master_attribute_attempts.attr, &w1_master_attribute_timeout.attr, + &w1_master_attribute_timeout_us.attr, &w1_master_attribute_pointer.attr, &w1_master_attribute_search.attr, &w1_master_attribute_pullup.attr, @@ -1108,7 +1122,8 @@ int w1_process(void *data) /* As long as w1_timeout is only set by a module parameter the sleep * time can be calculated in jiffies once. */ - const unsigned long jtime = msecs_to_jiffies(w1_timeout * 1000); + const unsigned long jtime = + usecs_to_jiffies(w1_timeout * 1000000 + w1_timeout_us); /* remainder if it woke up early */ unsigned long jremain = 0; |