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Message-ID: <9b1cb44f-43dc-8926-9dab-00032ab59640@collabora.com>
Date:   Wed, 20 Apr 2022 11:36:20 +0200
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Subject: Re: [PATCH 2/2] iio: stk3310: Export near level property for
 proximity sensor
Content-Language: en-US
To:     Jonathan Cameron <jic23@kernel.org>
Cc:     Lars-Peter Clausen <lars@metafoo.de>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzk+dt@kernel.org>,
        linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, kernel@collabora.com
References: <20220415085018.35063-1-arnaud.ferraris@collabora.com>
 <20220415085018.35063-3-arnaud.ferraris@collabora.com>
 <20220416172651.695d4439@jic23-huawei>
From:   Arnaud Ferraris <arnaud.ferraris@collabora.com>
In-Reply-To: <20220416172651.695d4439@jic23-huawei>
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Hi Jonathan,

Le 16/04/2022 à 18:26, Jonathan Cameron a écrit :
> On Fri, 15 Apr 2022 10:50:18 +0200
> Arnaud Ferraris <arnaud.ferraris@collabora.com> wrote:
> 
>> This makes the value from which an object should be considered "near"
>> available to userspace. This hardware-dependent value should be set
>> in the device-tree.
>>
>> Signed-off-by: Arnaud Ferraris <arnaud.ferraris@collabora.com>
> Hi Arnaud,
> 
> Minor request to slightly modify how you do this inline.
> Otherwise looks good to me.
> 
> Thanks,
> 
> Jonathan
> 
>> ---
>>   drivers/iio/light/stk3310.c | 26 ++++++++++++++++++++++++++
>>   1 file changed, 26 insertions(+)
>>
>> diff --git a/drivers/iio/light/stk3310.c b/drivers/iio/light/stk3310.c
>> index 1d02dfbc29d1..7792456323ef 100644
>> --- a/drivers/iio/light/stk3310.c
>> +++ b/drivers/iio/light/stk3310.c
>> @@ -106,6 +106,7 @@ struct stk3310_data {
>>   	struct mutex lock;
>>   	bool als_enabled;
>>   	bool ps_enabled;
>> +	uint32_t ps_near_level;
>>   	u64 timestamp;
>>   	struct regmap *regmap;
>>   	struct regmap_field *reg_state;
>> @@ -135,6 +136,25 @@ static const struct iio_event_spec stk3310_events[] = {
>>   	},
>>   };
>>   
>> +static ssize_t stk3310_read_near_level(struct iio_dev *indio_dev,
>> +				       uintptr_t priv,
>> +				       const struct iio_chan_spec *chan,
>> +				       char *buf)
>> +{
>> +	struct stk3310_data *data = iio_priv(indio_dev);
>> +
>> +	return sprintf(buf, "%u\n", data->ps_near_level);
>> +}
>> +
>> +static const struct iio_chan_spec_ext_info stk3310_ext_info[] = {
>> +	{
>> +		.name = "nearlevel",
>> +		.shared = IIO_SEPARATE,
>> +		.read = stk3310_read_near_level,
>> +	},
>> +	{ /* sentinel */ }
>> +};
>> +
>>   static const struct iio_chan_spec stk3310_channels[] = {
>>   	{
>>   		.type = IIO_LIGHT,
>> @@ -151,6 +171,7 @@ static const struct iio_chan_spec stk3310_channels[] = {
>>   			BIT(IIO_CHAN_INFO_INT_TIME),
>>   		.event_spec = stk3310_events,
>>   		.num_event_specs = ARRAY_SIZE(stk3310_events),
>> +		.ext_info = stk3310_ext_info,
>>   	}
>>   };
>>   
>> @@ -581,6 +602,11 @@ static int stk3310_probe(struct i2c_client *client,
>>   	data = iio_priv(indio_dev);
>>   	data->client = client;
>>   	i2c_set_clientdata(client, indio_dev);
>> +
>> +	if (device_property_read_u32(&client->dev, "proximity-near-level",
>> +				     &data->ps_near_level))
>> +		data->ps_near_level = 0;
> 
> Prefer this pattern.
> 
> 	data->ps_near_level = 0;
> 	device_property_read_u32(&client->dev, "proximity-near-level",
> 				 &data->ps_near_level);
> taking advantage of the fact that the output won't be set unless
> the property read succeeds.

That's a good suggestion indeed! We can even get rid of the initial 
assignment as the struct is zero-initialized on alloc, will send a v2 in 
a moment.

Thanks,
Arnaud

> 
>> +
>>   	mutex_init(&data->lock);
>>   
>>   	ret = stk3310_regmap_init(data);
>