From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bear.ext.ti.com ([192.94.94.41]:37712 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753486AbaIVOJZ (ORCPT ); Mon, 22 Sep 2014 10:09:25 -0400 Date: Mon, 22 Sep 2014 09:09:14 -0500 From: Felipe Balbi To: Felipe Balbi CC: Jonathan Cameron , , , Andrew Morton Subject: Re: [RESEND PATCH] iio: light: add support for TI's opt3001 light sensor Message-ID: <20140922140914.GC25620@saruman> Reply-To: References: <1409671066-25747-1-git-send-email-balbi@ti.com> <54147632.9090204@kernel.org> <20140915052137.GA11866@saruman.home> <20140916170316.GD19010@saruman.home> <20140917150041.GA6903@saruman.home> <20140918133631.GA24847@saruman.home> <20140919162129.GE26946@saruman.home> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="GPJrCs/72TxItFYR" In-Reply-To: <20140919162129.GE26946@saruman.home> Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org --GPJrCs/72TxItFYR Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable ping On Fri, Sep 19, 2014 at 11:21:29AM -0500, Felipe Balbi wrote: > ping >=20 > On Thu, Sep 18, 2014 at 08:36:31AM -0500, Felipe Balbi wrote: > > ping > >=20 > > On Wed, Sep 17, 2014 at 10:00:41AM -0500, Felipe Balbi wrote: > > > ping > > >=20 > > > On Tue, Sep 16, 2014 at 12:03:16PM -0500, Felipe Balbi wrote: > > > > ping > > > >=20 > > > > On Mon, Sep 15, 2014 at 12:21:37AM -0500, Felipe Balbi wrote: > > > > > Hi, > > > > >=20 > > > > > 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. > > > > > > >=20 > > > > > > > This patch adds support for that device using the IIO > > > > > > > framework. > > > > > > >=20 > > > > > > > Signed-off-by: Felipe Balbi > > > > > > > --- > > > > > > >=20 > > > > > > > Resending as I saw no changes on the thread. > > > > > > Hi Felipe, > > > > > >=20 > > > > > > 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!) > > > > >=20 > > > > > right, this is starting to become way too much headache for such a > > > > > simple device. Sorry will not help me getting this driver upstrea= m. 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. > > > > >=20 > > > > > > Anyhow, I'm afraid I am still a little confused about the meani= ng you > > > > > > have assigned to Hysteresis in this driver. > > > > > >=20 > > > > > > Let me conjecture on what might be going on here (I may be enti= rely > > > > > > wrong). > > > > > >=20 > > > > > > 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 even= ts 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. > > > > > >=20 > > > > > > So having the same register for both the hysteresis and the thr= eshold > > > > > > doesn't with this description make much sense. It would mean t= hat you > > > > > > could only have a threshold of say 10 and a hysteresis of 10, t= hus in > > > > > > effect meaning the signal would always have to cross 0 before t= he next > > > > > > event whatever the combined threshold / hysteresis value? > > > > > >=20 > > > > > > Perhaps instead the device is automatically adjusting the thres= hold > > > > > > when we cross it and the 'hysteresis' here is with respect to a= the > > > > > > previous threshold? > > > > > >=20 > > > > > > Thus if we start with a value of 0 and hysteresis is set to 2 i= t will > > > > > > trigger an event at: > > > > > >=20 > > > > > > 2, 4, 6, 8, 10 as we rise? > > > > > >=20 > > > > > > This sort of auto adjustment of levels isn't uncommon in light = sensors > > > > > > (where the point of the interrupt is to notify the operating sy= stem > > > > > > that a 'significant' change has occurred and things like screen > > > > > > brightness may need adjusting. > > > > > >=20 > > > > > > If so then the current hysteresis interface does not apply, nor= does > > > > > > the Rate of Change (ROC) interface as this is dependent on amou= nt 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_ris= ing_value > > > > > >=20 > > > > > > etc? > > > > >=20 > > > > > 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 su= ch a > > > > > simple little device, not to mention your confusing and contradic= ting > > > > > change requests. > > > > >=20 > > > > > (could you also trim your responses ? it's very annoying to scrol= l so > > > > > much) > > > > >=20 > > > > > > > +#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 */ > > > > > > > + > > > > > >=20 > > > > > > I guess this naming is straight off the datasheet, but it is ra= ther > > > > > > more cryptic than perhaps it needs to be! That's kind of an is= sue > > > > > > with the datasheet choices rather than what you have here howev= er! > > > > >=20 > > > > > 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/develope= rs of > > > > > these driver will need either a shit ton of comments explaining t= hat 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. > > > > >=20 > > > > > > > +static int opt3001_remove(struct i2c_client *client) > > > > > > > +{ > > > > > > > + struct iio_dev *iio =3D i2c_get_clientdata(client); > > > > > > > + struct opt3001 *opt =3D iio_priv(iio); > > > > > > > + int ret; > > > > > > > + u16 reg; > > > > > > > + > > > > > > > + free_irq(client->irq, iio); > > > > > > > + iio_device_unregister(iio); > > > > > > > + > > > > > > > + ret =3D i2c_smbus_read_word_swapped(opt->client, OPT3001_CO= NFIGURATION); > > > > > > > + if (ret < 0) { > > > > > > > + dev_err(opt->dev, "failed to read register %02x\n", > > > > > > > + OPT3001_CONFIGURATION); > > > > > > > + return ret; > > > > > > > + } > > > > > > > + > > > > > > > + reg =3D ret; > > > > > > > + opt3001_set_mode(opt, ®, OPT3001_CONFIGURATION_M_SHUTDOW= N); > > > > > > > + > > > > > > > + ret =3D i2c_smbus_write_word_swapped(opt->client, OPT3001_C= ONFIGURATION, > > > > > > > + 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 wil= l 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. > > > > >=20 > > > > > here's the original driver: > > > > >=20 > > > > > http://www.spinics.net/lists/linux-iio/msg14331.html > > > > >=20 > > > > > notice that it *WAS* *USING* devm_iio_device_alloc(), until: > > > > >=20 > > > > > http://www.spinics.net/lists/linux-iio/msg14421.html > > > > >=20 > > > > > you *SPECIFICALLY* asked for *NON* *DEVM* versions!! > > > > >=20 > > > > > 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 s= ent > > > > > 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 ju= st put > > > > > me in a bad mood, even before Monday, hurray. > > > > >=20 > > > > > cheers > > > > >=20 > > > > > --=20 > > > > > balbi > > > >=20 > > > >=20 > > > >=20 > > > > --=20 > > > > balbi > > >=20 > > >=20 > > >=20 > > > --=20 > > > balbi > >=20 > >=20 > >=20 > > --=20 > > balbi >=20 >=20 >=20 > --=20 > balbi --=20 balbi --GPJrCs/72TxItFYR Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJUIC2KAAoJEIaOsuA1yqREapEP/jSEkfW4e8Tu9e4eQ8hKkrB3 dhSaMP7dT1SvwLkPJRKwzrD4VXjSJtppcRiOK1ZMi8NxnrcM3J0/8so5YBKcFkvG xvJhb54WwEp5U4sLkFFW/Ogpz5z/l/0rr+bffvGUauA+cwk8ipSIuxz3AYe0zxdW Ewsa6LQkMohlt6ieOdCs9JYrVONT25QXnhfWUyNe8UZma8IgMsfPqWPn7Au3flag u6ggvHNuM71jhaqq93mEC7eU1U6cbhskAvDhX0ovDfHOUZeEFcUbXmEIeMjyVkZr OeftR1cPN41TqDC0jHqi//dvcWzvFk8d6bd8dxdO+6lh839OLHvOOSt8p/4GpvnD 0foVoOU7h1oTWyiDqDAzsxbS0um80fMaJislJy3eIVrgNSy6Cgd7L74OXjPy7EZh 5yrhH9HIIRyFkVXa5vJ04v1wKMemp1CYlpNntgTTpNQxTNMbY2bJ0JvLlt72WwGg ZTnuxjxyLuU9SzIyKJqRfhv+WKyB5GIBXSgowjiXD4D9TQyCRW5v3rjjjL9fQw4l oxNLP/gOxWI7JYrdGOdgK7GvIEitvaDZGukY910PpDRd0kKaf2t+EGFais3E1aGh wk6QN7DFRflTGZhLrjQr1OgfLQ5WU+l2613A7P1HuibR3M3sBPZDFQWy+N3d13jU wATcBS4/ITSEl5Y2THlb =jRbe -----END PGP SIGNATURE----- --GPJrCs/72TxItFYR--