On Sun, Mar 12, 2017 at 10:57:43AM -0700, Guenter Roeck wrote: > On 03/12/2017 07:47 AM, Sam Povilus wrote: > > Adding the ability for the ads7828 and ads7830 to use the device tree to > > get their optional parameters, instead of using platform devices. This > > allows people using custom boards to also use the ads7828 in a non-default > > manner. > > > > Also adding a note to the user if they misconfigure the device's external > > reference. > > > > v2: conforming to coding style > > v3: changing from "_" to "-" for device tree entries > > Signed-off-by: Sam Povilus <kernel.development@xxxxxxxx> > > --- > > Documentation/devicetree/bindings/hwmon/ads7828.txt | 18 ++++++++++++++++++ > > .../devicetree/bindings/i2c/trivial-devices.txt | 2 -- > > drivers/hwmon/ads7828.c | 15 +++++++++++++++ > > 3 files changed, 33 insertions(+), 2 deletions(-) > > create mode 100644 Documentation/devicetree/bindings/hwmon/ads7828.txt > > > > diff --git a/Documentation/devicetree/bindings/hwmon/ads7828.txt b/Documentation/devicetree/bindings/hwmon/ads7828.txt > > new file mode 100644 > > index 000000000000..0d37cd3fd31b > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/hwmon/ads7828.txt > > @@ -0,0 +1,18 @@ > > +ads7828 properties > > + > > +Required properties: > > +- compatible: > > + Should be one of > > + ti,ads7828 > > + ti,ads7830 > > +- reg: I2C address > > + > > +Optional properties: > > + > > +- diff-input > > + Set to use the device in differential mode. > > I'll wait for Rob to comment, but "differential-input" sounds better to me, > Also, it would have to have a "ti," prefix. > The platform device uses diff_input, are we going for consistancy or correctness? I am good with either. > > +- ext-vref > > + Set to enable the external voltage reference on the device. > > +- vref-mv > > + The external reference on the device is set to this as an unsigned integer in > > + milivolts. Must use "ext_vref" for this to have any meaning. > > ext_vref, though as suggested below I think it would be better to use a standard > property. Also, it seems to me that ext-vref is really unnecessary; the presence > of "vref" can imply that the reference voltage is external. > I agree, but again, the platform device seperates it. Consistancy or correctness? > > diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt > > index cdd7b48826c3..87648909f6ce 100644 > > --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt > > +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt > > @@ -163,8 +163,6 @@ st,m41t00 Serial real-time clock (RTC) > > st,m41t62 Serial real-time clock (RTC) with alarm > > st,m41t80 M41T80 - SERIAL ACCESS RTC WITH ALARMS > > taos,tsl2550 Ambient Light Sensor with SMBUS/Two Wire Serial Interface > > -ti,ads7828 8-Channels, 12-bit ADC > > -ti,ads7830 8-Channels, 8-bit ADC > > ti,tsc2003 I2C Touch-Screen Controller > > ti,tmp102 Low Power Digital Temperature Sensor with SMBUS/Two Wire Serial Interface > > ti,tmp103 Low Power Digital Temperature Sensor with SMBUS/Two Wire Serial Interface > > diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c > > index ee396ff167d9..d1f7ba5d7a2b 100644 > > --- a/drivers/hwmon/ads7828.c > > +++ b/drivers/hwmon/ads7828.c > > @@ -118,6 +118,7 @@ static int ads7828_probe(struct i2c_client *client, > > struct ads7828_data *data; > > struct device *hwmon_dev; > > unsigned int vref_mv = ADS7828_INT_VREF_MV; > > + unsigned int vref_mv_tmp; > > bool diff_input = false; > > bool ext_vref = false; > > unsigned int regval; > > @@ -131,11 +132,25 @@ static int ads7828_probe(struct i2c_client *client, > > ext_vref = pdata->ext_vref; > > if (ext_vref && pdata->vref_mv) > > vref_mv = pdata->vref_mv; > > + } else if (dev->of_node) { > > + if (of_get_property(dev->of_node, "diff-input", NULL)) > > + diff_input = true; > > + if (of_get_property(dev->of_node, "ext-vref", NULL)) > > + ext_vref = true; > > + if (!of_property_read_u32(dev->of_node, "vref-mv", &vref_mv_tmp) > > + && ext_vref) > > + vref_mv = vref_mv_tmp; > > Please consider using devm_regulator_get_optional() and thus standard properties. > I'd have to disagree with this, but not strongly. In my reading of Documentation/power/regulator/overview.txt it seems like the regulator subsystem is exclusivly for regulators not for references. I would hope that most board designers would not use a regulator, and especially not a switch mode regulator for the input to a reference. Am I reading the regulator subsystem overview wrong? or are people using it for things that it's not quite intended (I will admit it looks like a number of other adcs use it)? or is there some other explination. > > } > > > > /* Bound Vref with min/max values */ > > + vref_mv_tmp = vref_mv; > > vref_mv = clamp_val(vref_mv, ADS7828_EXT_VREF_MV_MIN, > > ADS7828_EXT_VREF_MV_MAX); > > + if (vref_mv_tmp != vref_mv) { > > + pr_info("You used and invalid external vref," > > + " it has been clamped to %u", > > + vref_mv); > > + } > > This is an unrelated change. > > > > > /* ADS7828 uses 12-bit samples, while ADS7830 is 8-bit */ > > if (id->driver_data == ads7828) { > > > -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html