Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver

From: Stanimir Varbanov <svarbanov@mm-sol.com>
To: "Ivan T. Ivanov" <iivanov@mm-sol.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>,
	Pawel Moll <pawel.moll@arm.com>, Rob Herring <robh+dt@kernel.org>,
	Kumar Gala <galak@codeaurora.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Grant Likely <grant.likely@linaro.org>,
	Jonathan Cameron <jic23@kernel.org>,
	Arnd Bergmann <arnd@arndb.de>,
	linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Hartmut Knaack <knaack.h@gmx.de>,
	Angelo Compagnucci <angelo.compagnucci@gmail.com>,
	Doug Anderson <dianders@chromium.org>,
	Fugang Duan <B38611@freescale.com>,
	Johannes Thumshirn <johannes.thumshirn@men.de>,
	Jean Delvare <jdelvare@suse.de>,
	Philippe Reynes <tremyfr@yahoo.fr>,
	Lee Jones <lee.jones@linaro.org>,
	Josh Cartwright <joshc@codeaurora.org>,
	Stephen Boyd <sboyd@codeaurora.org>,
	David Collins <collinsd@codeaurora.org>
Subject: Re: [PATCH v3 1/2] iio: vadc: Qualcomm SPMI PMIC voltage ADC driver
Date: Thu, 25 Sep 2014 18:30:59 +0300	[thread overview]
Message-ID: <54243533.7080809@mm-sol.com> (raw)
In-Reply-To: <1411649225.18580.134.camel@iivanov-dev>

Hi Ivan,

On 09/25/2014 03:47 PM, Ivan T. Ivanov wrote:
> 
> Hi Stan, few comment bellow.
> 
> On Wed, 2014-09-24 at 15:56 +0300, Stanimir Varbanov wrote:
>> The voltage ADC is peripheral of Qualcomm SPMI PMIC chips. It has
>> 15bits resolution and register space inside PMIC accessible across
>> SPMI bus.
>>
>> The vadc driver registers itself through IIO interface.
>>
>> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
>> Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
>> ---
>>  drivers/iio/adc/Kconfig                       |   10 +
>>  drivers/iio/adc/Makefile                      |    1 +
>>  drivers/iio/adc/qcom-spmi-vadc.c              | 1029 +++++++++++++++++++++++++
>>  include/dt-bindings/iio/qcom,spmi-pmic-vadc.h |  119 +++
>>  4 files changed, 1159 insertions(+), 0 deletions(-)
>>  create mode 100644 drivers/iio/adc/qcom-spmi-vadc.c
>>  create mode 100644 include/dt-bindings/iio/qcom,spmi-pmic-vadc.h
>>
>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>> index 11b048a..ec48360 100644
>> --- a/drivers/iio/adc/Kconfig
>> +++ b/drivers/iio/adc/Kconfig
>> @@ -206,6 +206,16 @@ config NAU7802
>>  	  To compile this driver as a module, choose M here: the
>>  	  module will be called nau7802.
>>  
>> +config QCOM_SPMI_VADC
>> +	tristate "Qualcomm SPMI PMIC voltage ADC"
>> +	depends on SPMI
> 
> + select REGMAP_SPMI

I'd suggest MFD_SPMI_PMIC symbol of the parent driver instead? The
parent MFD PMIC driver already selects REGMAP_SPMI and depends on SPMI.

> 
> <snip>
> 
>> +
>> +static int vadc_read(struct vadc_priv *vadc, u16 offset, u8 *data)
>> +{
>> +	return regmap_bulk_read(vadc->regmap, vadc->base + offset, data, 1);
> 
> just regmap_read() ?

No, regmap_read() expects unsigned int *val as an argument hence I will
need temporary variable. I had a comment to rework this on the first
version of the patchset.

> 
>> +}
>> +
> 
> General comment, most of the dev_dbg looks like legitimate dev_err's to me.

I've decided to not flood console with messages. If someone wants to
debug why the driver doesn't probed he can define DEBUG.

-- 
regards,
Stan