On Sun, 18 Jan 2009 17:32:54 +0000 Jonathan Cameron <jic23 at cam.ac.uk> wrote: > From: Jonathan Cameron <jic23 at cam.ac.uk> > hwmon: SHT15 and similar Sensiron humidity sensors > Signed-off-by: Jonathan Cameron <jic23 at cam.ac.uk> > > --- > Depends on: > Regulator: Add voltage change event notification > (to be posted to lkml shortly - it needs rebasing as that subsystem > is changing rapidly at the mo!) > > Data sheet at: > http://www.sensirion.ch/en/pdf/product_information/Datasheet-humidity-sensor-SHT1x.pdf > > These sensors communicate over a 2 wire bus running a device specific > protocol. The complexity of the driver is mainly due to handling the > substantial delays between requesting a reading and the device pulling > the data line low to indicate that the data is available. This is > handled by an interrupt that is disabled under all other conditions. > > I wasn't terribly clear on the best way to handle this, so comments > on that aspect would be particularly welcome! > > Interpretation of the temperature depends on knowing the supply voltage. > If configured in a board config as a regulator consumer this is obtained > from the regulator subsystem. If not it should be provided in the > platform data. > > I've placed this driver in the hwmon subsystem as it is definitely a > device that may be used for hardware monitoring and with it's relatively > slow response times (up to 120 milisecs to get a reading) a caching > strategy certainly seems to make sense! > Building this in current kernels on x86_64 gives drivers/hwmon/sht15.c: In function 'sht15_update_single_val': drivers/hwmon/sht15.c:237: error: implicit declaration of function 'IRQ_GPIO' > > ... > > +static int __init sht15_init(void) > +{ > + int ret; > + int i; > + > + for (i = 0; i < ARRAY_SIZE(sht_drivers); i++) { > + ret = platform_driver_register(&sht_drivers[i]); > + if (ret) > + goto error_unreg; > + } > + > + return 0; > + > +error_unreg: > + i--; > + for (; i >= 0; i--) > + platform_driver_unregister(&sht_drivers[i]); > + > + return ret; > +} We could just do while (--i >= 0) platform_driver_unregister(...); here. Anyway, please take a look at those things and Cc: me on version 2 and we'll try to push forward with this, thanks.
