Messages in this thread | | | Subject | Re: [PATCH v2 1/2] iio: ina2xx: add support for TI INA2xx Power Monitors | From | Guenter Roeck <> | Date | Wed, 2 Dec 2015 08:44:40 -0800 |
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On 12/02/2015 08:20 AM, Marc Titinger wrote: > On 02/12/2015 17:04, Guenter Roeck wrote: >> On 12/02/2015 02:20 AM, Marc Titinger wrote: >>> On 02/12/2015 03:14, Guenter Roeck wrote: >>>> On Mon, Nov 30, 2015 at 12:49:14PM +0100, Marc Titinger wrote: >>>>> in SOFTWARE buffer mode, a kthread will capture the active >>>>> scan_elements >>>>> into a kfifo, then compute the remaining time until the next capture >>>>> tick >>>>> and do an active wait (udelay). >>>>> >>>>> This will produce a stream of up to fours channels plus a 64bits >>>>> timestamps (ns). >>>>> >>>>> Tested with ina226, on BeagleBoneBlack. >>>>> >>>>> Datasheet: http://www.ti.com/lit/gpn/ina226 >>>>> >>>>> Signed-off-by: Marc Titinger <mtitinger@baylibre.com> >>>>> --- >>>>> drivers/iio/adc/Kconfig | 9 + >>>>> drivers/iio/adc/Makefile | 1 + >>>>> drivers/iio/adc/ina2xx-iio.c | 678 >>>>> +++++++++++++++++++++++++++++++++++++++++++ >>>>> 3 files changed, 688 insertions(+) >>>>> create mode 100644 drivers/iio/adc/ina2xx-iio.c >>>>> + >>>> [ ... ] >>>>> + >>>>> +static const struct i2c_device_id ina2xx_id[] = { >>>>> + {"ina219", ina219}, >>>>> + {"ina220", ina219}, >>>>> + {"ina226", ina226}, >>>>> + {"ina230", ina226}, >>>>> + {"ina231", ina226}, >>>>> + {} >>>>> +}; >>>> >>>> I wonder what is going to happen if both this driver and the hwmon >>>> driver for the same chips are configured in a system which supports >>>> devicetree (or any system, really). Unless I am missing something, >>>> the result will be that both drivers will try to instantiate, and >>>> one will fail with -EBUSY. Or the instantiated driver is more or less >>>> random, depending on which one happens to be loaded. Not a good >>>> situation to be in. >>> >>> I agree, we should put a mutual exclusion in Kconfig, plus maybe a >>> cross-reference in the help section. >>> >>>> >>>> For the time being, it might make sense to add cross-dependencies >>>> in Kconfig to only permit one of the two drivers to be configured. >>>> >>>> Ultimately we may need a better solution for the iio-hwmon bridge, >>>> one that makes the underlying driver transparent in both devicetree >>>> properties and user space ABI. No idea how to do that, though. >>>> >>> >>> IDK if ina2xx is a special case or if this matter of dual driver >>> stacks for the same chip already occurred and requires specific >>> plumbing. Making the user aware of the mutual of the exclusion sounds >>> fine with me. >>> >> htu21. We'll drop that driver from hwmon with the 4.5 kernel. >> We could just drop ina2xx as well, but it is more widely used >> and referenced from dts files. The ABI changes, so I am not sure >> if we can just do that. > > I changed iio/adc/Kconfig to the following: > > +config INA2XX_ADC > + tristate "Texas Instruments INA2xx Power Monitors IIO driver" > + depends on I2C && !SENSORS_INA2XX > + select REGMAP_I2C > + select IIO_BUFFER > + select IIO_KFIFO_BUF > + help > + Say yes here to build support for TI INA2xx family of Power Monitors. > + This driver is mutually exclusive with the HWMON version. > + > > > anything the patch should also add to hwmon/Kconfig (that will not lead to a cycling reference warning) ? >
You could try the opposite, but I don't know if that works.
depends on I2C && !INA2XX_ADC
Guenter
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