http://marc.info/?l=linux-iio&m=141077611429500&w=2 On September 16, 2014 6:03:16 PM GMT+01:00, Felipe Balbi <balbi@xxxxxx> wrote: >ping > >On Mon, Sep 15, 2014 at 12:21:37AM -0500, Felipe Balbi wrote: >> Hi, >> >> On Sat, Sep 13, 2014 at 05:52:02PM +0100, Jonathan Cameron wrote: >> > On 02/09/14 16:17, Felipe Balbi wrote: >> > > TI's opt3001 light sensor is a simple and yet powerful >> > > little device. The device provides 99% IR rejection, >> > > Automatic full-scale, very low power consumption and >> > > measurements from 0.01 to 83k lux. >> > > >> > > This patch adds support for that device using the IIO >> > > framework. >> > > >> > > Signed-off-by: Felipe Balbi <balbi@xxxxxx> >> > > --- >> > > >> > > Resending as I saw no changes on the thread. >> > Hi Felipe, >> > >> > Sorry for the delay on this, entirely my fault - been busy and >forgot >> > I still had questions about what was going on in here (yup its the >> > hysteresis bit again!) >> >> right, this is starting to become way too much headache for such a >> simple device. Sorry will not help me getting this driver upstream. >When >> I first sent this (August 6), we didn't even have v3.17-rc1, now >we're >> about to tag -rc5 and I'm worried this driver will not hit v3.18 >merge >> window. >> >> > Anyhow, I'm afraid I am still a little confused about the meaning >you >> > have assigned to Hysteresis in this driver. >> > >> > Let me conjecture on what might be going on here (I may be entirely >> > wrong). >> > >> > Normally a hysteresis value in IIO is defined as the 'distance' >back >> > from a threshold that a signal must go before it may retrip the >> > threshold. >> > This threshold value is separately controlled. Thus if we have a >> > rising threshold of 10 and an hysteresis of 2 - to get two events >the >> > signal must first rise past 10, then drop back below 8 and rise >again >> > past 10. >> > If it drops below 10 but not 8 and rises again past 10 then we will >> > not get an event. >> > >> > So having the same register for both the hysteresis and the >threshold >> > doesn't with this description make much sense. It would mean that >you >> > could only have a threshold of say 10 and a hysteresis of 10, thus >in >> > effect meaning the signal would always have to cross 0 before the >next >> > event whatever the combined threshold / hysteresis value? >> > >> > Perhaps instead the device is automatically adjusting the threshold >> > when we cross it and the 'hysteresis' here is with respect to a the >> > previous threshold? >> > >> > Thus if we start with a value of 0 and hysteresis is set to 2 it >will >> > trigger an event at: >> > >> > 2, 4, 6, 8, 10 as we rise? >> > >> > This sort of auto adjustment of levels isn't uncommon in light >sensors >> > (where the point of the interrupt is to notify the operating system >> > that a 'significant' change has occurred and things like screen >> > brightness may need adjusting. >> > >> > If so then the current hysteresis interface does not apply, nor >does >> > the Rate of Change (ROC) interface as this is dependent on amount >of >> > change, not how fast it changed. Hence we needs something new to >> > handle this cleanly. I would suggest a new event type. Perhaps >> > something with sysfs attr naming along the lines of >> > What: /sys/.../iio:deviceX/events/in_light_change_rising_en >> > What: >/sys/.../iio:deviceX/events/in_light_change_rising_value >> > >> > etc? >> >> will you just tell me what you want ? I really cannot give a crap >> anymore. This has already taken me over a month of my time for such a >> simple little device, not to mention your confusing and contradicting >> change requests. >> >> (could you also trim your responses ? it's very annoying to scroll so >> much) >> >> > > +#define OPT3001_RESULT 0x00 >> > > +#define OPT3001_CONFIGURATION 0x01 >> > > +#define OPT3001_LOW_LIMIT 0x02 >> > > +#define OPT3001_HIGH_LIMIT 0x03 >> > > +#define OPT3001_MANUFACTURER_ID 0x7e >> > > +#define OPT3001_DEVICE_ID 0x7f >> > > + >> > > +#define OPT3001_CONFIGURATION_RN_MASK (0xf << 12) >> > > +#define OPT3001_CONFIGURATION_RN_AUTO (0xc << 12) >> > > + >> > > +#define OPT3001_CONFIGURATION_CT BIT(11) >> > > + >> > > +#define OPT3001_CONFIGURATION_M_MASK (3 << 9) >> > > +#define OPT3001_CONFIGURATION_M_SHUTDOWN (0 << 9) >> > > +#define OPT3001_CONFIGURATION_M_SINGLE (1 << 9) >> > > +#define OPT3001_CONFIGURATION_M_CONTINUOUS (2 << 9) /* also 3 << >9 */ >> > > + >> > >> > I guess this naming is straight off the datasheet, but it is rather >> > more cryptic than perhaps it needs to be! That's kind of an issue >> > with the datasheet choices rather than what you have here however! >> >> man, are you nit-picky!! These are named as such to make grepping on >> documentation easier. It's better to have something that matches >> documentation, don't you think ? otherwise, future users/developers >of >> these driver will need either a shit ton of comments explaining that >A >> maps to B in docs, or will need a fscking crystal ball to read my >mind. >> Assuming I'll still remember what I meant. >> >> > > +static int opt3001_remove(struct i2c_client *client) >> > > +{ >> > > + struct iio_dev *iio = i2c_get_clientdata(client); >> > > + struct opt3001 *opt = iio_priv(iio); >> > > + int ret; >> > > + u16 reg; >> > > + >> > > + free_irq(client->irq, iio); >> > > + iio_device_unregister(iio); >> > > + >> > > + ret = i2c_smbus_read_word_swapped(opt->client, >OPT3001_CONFIGURATION); >> > > + if (ret < 0) { >> > > + dev_err(opt->dev, "failed to read register %02x\n", >> > > + OPT3001_CONFIGURATION); >> > > + return ret; >> > > + } >> > > + >> > > + reg = ret; >> > > + opt3001_set_mode(opt, ®, OPT3001_CONFIGURATION_M_SHUTDOWN); >> > > + >> > > + ret = i2c_smbus_write_word_swapped(opt->client, >OPT3001_CONFIGURATION, >> > > + reg); >> > > + if (ret < 0) { >> > > + dev_err(opt->dev, "failed to write register %02x\n", >> > > + OPT3001_CONFIGURATION); >> > > + return ret; >> > > + } >> > > + >> > > + iio_device_free(iio); >> > >> > Use the devm_iio_device_alloc and you can drop the need to free it. >> > I don't really mind, but I'll almost guarantee that someone will >post >> > a follow up patch doing this if you don't. As it will be ever so >> > slightly cleaner, I'll probably take that patch. >> >> here's the original driver: >> >> http://www.spinics.net/lists/linux-iio/msg14331.html >> >> notice that it *WAS* *USING* devm_iio_device_alloc(), until: >> >> http://www.spinics.net/lists/linux-iio/msg14421.html >> >> you *SPECIFICALLY* asked for *NON* *DEVM* versions!! >> >> So figure out what you really want, let me know and I'll code it all >up >> quickly and hopefully still get this into v3.18 merge window. I sent >> this driver *very* early to be doubly sure it would hit v3.18 and >there >> was a long hiatus from yourself which is now jeopardizing what I was >> expecting. That, coupled with your contradicting requests, has just >put >> me in a bad mood, even before Monday, hurray. >> >> cheers >> >> -- >> balbi -- Sent from my Android phone with K-9 Mail. Please excuse my brevity. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
