On Thu, 2 Jun 2005 13:09:52 -0400 <BGardner at Wabtec.com> wrote: Hello, Ben. I very like your changes, although I did not tested it yet, will do it later this week. But I have some comments about. > While writing a driver for the DS2482 (an i2c to w1 bridge), > I made a few enhancements to the w1 subsystem. > > 1. > I added a new I/O function: triplet > A triplet reads two bits and writes a direction bit. The DS2482 > implements this in hardware. > I modified w1_search() to use w1_triplet() at its core. > > 2. > I cleaned up the I/O functions to separate emulated vs native w1 > support. > A w1 bus master must be able to do one of: > a. Set and sample the line via write_bit() and read_bit() > b. Support reset_bus() and touch_bit() > Function set (a) is only needed for emulated devices (ie, a parallel > port). > I hid w1_read_bit() and w1_write_bit() behind w1_touch_bit(), and > changed functions to call touch_bit() instead or read/write_bit(). This changes are quite good. > 3. > Searching is fairly slow - it requires about 200 w1 bit cycles per > device, multiplied by the number of devices on the bus. > I modified the w1_process() to NOT periodically search the bus. > A sysfs entry was added to request a search. (w1_master_search). > To request a search, echo anything into w1_master_search and it'll run > another search. This one is very usefull, but we do want a mode, when w1 core repeatedly scans for devices - concider ibuttons which can only "exists" and be found for a couple of seconds, and it is not always possible and sensible to have some userspace writing to the sysfs file. I would like to have 2 search modes - writing "1" to sysfs turns default always-scan mode into write-on-request mode, and writing "2" turns it back. Or something similar... > 4. > I added a default family so that a slave device will get reported even > if there isn't a driver for that family. > > Signed-off-by: Ben Gardner <bgardner at wabtec.com> Besides some whitespace and some brackets places [ugh, Greg will kill me for such patches] and my above comment I do not have objections, but I would like to test your changes first and see them presented in a splitted series of patches. I see almost 10 major changes in your patch :) Thank you. Evgeniy Polyakov Only failure makes us experts. -- Theo de Raadt
