linux-kernel - Re: [PATCH v4 3/3] iio: adc: add support for Allwinner SoCs ADC

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Message-ID: <f085ee35-889f-58e3-15d6-e6f3c0d15a92@free-electrons.com>
Date:   Mon, 5 Sep 2016 08:29:20 +0200
From:   Quentin Schulz <quentin.schulz@...e-electrons.com>
To:     Jonathan Cameron <jic23@...nel.org>, jdelvare@...e.com,
        Guenter Roeck <linux@...ck-us.net>, knaack.h@....de,
        lars@...afoo.de, pmeerw@...erw.net, wens@...e.org,
        lee.jones@...aro.org
Cc:     thomas.petazzoni@...e-electrons.com,
        antoine.tenart@...e-electrons.com, linux-kernel@...r.kernel.org,
        linux-hwmon@...r.kernel.org, linux-iio@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        Zhang Rui <rui.zhang@...el.com>,
        Eduardo Valentin <edubezval@...il.com>,
        linux-pm <linux-pm@...r.kernel.org>
Subject: Re: [PATCH v4 3/3] iio: adc: add support for Allwinner SoCs ADC

On 04/09/2016 16:35, Jonathan Cameron wrote:
> On 01/09/16 15:05, Quentin Schulz wrote:
>> The Allwinner SoCs all have an ADC that can also act as a touchscreen
>> controller and a thermal sensor. This patch adds the ADC driver which is
>> based on the MFD for the same SoCs ADC.
>>
>> This also registers the thermal adc channel in the iio map array so
>> iio_hwmon could use it without modifying the Device Tree. This registers
>> the driver in the thermal framework.
>>
>> This driver probes on three different platform_device_id to take into
>> account slight differences (registers bit and temperature computation)
>> between Allwinner SoCs ADCs.
>>
>> Signed-off-by: Quentin Schulz <quentin.schulz@...e-electrons.com>
> One utterly trivial point about unrolling code ordering inline.
> 
> Other than the bit about patch 1 I'm basically happy with this..

ACK. Will revert this patch in v5. Thanks.

> However I would like some input (i.e. an Ack) from thermal given this
> sets up a thermal zone.
> 
> Zhang or Eduardo, could you take a quick look at this and confirm you
> are happy with it?
> 
> Thanks,
> 
> Jonathan
[...]
>> +
>> +err_map:
>> +	iio_map_array_unregister(indio_dev);
>> +
>> +err_fifo_irq:
>> +	/* Disable FIFO_DATA_PENDING interrupt on hardware side. */
>> +	regmap_update_bits(info->regmap, SUN4I_GPADC_INT_FIFOC,
>> +			   SUN4I_GPADC_INT_FIFOC_TP_DATA_IRQ_EN,
>> +			   0);
>> +
>> +err_temp_irq:
>> +	/* Disable TEMP_DATA_PENDING interrupt on hardware side. */
>> +	regmap_update_bits(info->regmap, SUN4I_GPADC_INT_FIFOC,
>> +			   SUN4I_GPADC_INT_FIFOC_TEMP_IRQ_EN,
>> +			   0);
>> +
>> +err:
>> +	pm_runtime_put(&pdev->dev);
>> +	pm_runtime_disable(&pdev->dev);
>> +
>> +	return ret;
>> +}
>> +
>> +static int sun4i_gpadc_remove(struct platform_device *pdev)
>> +{
>> +	struct sun4i_gpadc_dev *info;
>> +	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
>> +
>> +	info = iio_priv(indio_dev);
>> +	iio_device_unregister(indio_dev);
>> +	iio_map_array_unregister(indio_dev);
>> +	pm_runtime_put(&pdev->dev);
>> +	pm_runtime_disable(&pdev->dev);
> Its really minor but in the interests of 'obviously correct' making
> review easy I'd rather everything in the remove was in the reverse order
> of probe (and hence the same as the error path in probe for most of it).
> 
> That would put the pm_runtime stuff last I think..
> 
> If you weren't rerolling anyway over patch 1 I'd probably have just let
> this go, but might as well make this trivial change as well.
> 

I'm going with the following order:
pm_runtime_put
pm_runtime_disable
regmap_update_bits
iio_map_array_unregister
iio_device_unregister

Is that okay? (I don't really know which one of iio_map_array_unregister
or iio_device_unregister to put first, if it matters in any way).

Thanks!
Quentin
> 
>> +	/*
>> +	 * Disable TEMP_DATA_PENDING and FIFO_DATA_PENDING interrupts on
>> +	 * hardware side.
>> +	 */
>> +	regmap_update_bits(info->regmap, SUN4I_GPADC_INT_FIFOC,
>> +			   SUN4I_GPADC_INT_FIFOC_TEMP_IRQ_EN |
>> +				SUN4I_GPADC_INT_FIFOC_TP_DATA_IRQ_EN,
>> +			   0);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct platform_device_id sun4i_gpadc_id[] = {
>> +	{ "sun4i-a10-gpadc-iio", (kernel_ulong_t)&sun4i_gpadc_soc_specific },
>> +	{ "sun5i-a13-gpadc-iio", (kernel_ulong_t)&sun5i_gpadc_soc_specific },
>> +	{ "sun6i-a31-gpadc-iio", (kernel_ulong_t)&sun6i_gpadc_soc_specific },
>> +	{ /* sentinel */ },
>> +};
>> +
>> +static struct platform_driver sun4i_gpadc_driver = {
>> +	.driver = {
>> +		.name = "sun4i-gpadc-iio",
>> +		.pm = &sun4i_gpadc_pm_ops,
>> +	},
>> +	.id_table = sun4i_gpadc_id,
>> +	.probe = sun4i_gpadc_probe,
>> +	.remove = sun4i_gpadc_remove,
>> +};
>> +
>> +module_platform_driver(sun4i_gpadc_driver);
>> +
>> +MODULE_DESCRIPTION("ADC driver for sunxi platforms");
>> +MODULE_AUTHOR("Quentin Schulz <quentin.schulz@...e-electrons.com>");
>> +MODULE_LICENSE("GPL v2");
>>
>