Message-ID: <20240829191957.GE3493@vamoiridPC>
Date: Thu, 29 Aug 2024 21:19:57 +0200
From: Vasileios Amoiridis <vassilisamir@...il.com>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: Vasileios Amoiridis <vassilisamir@...il.com>, jic23@...nel.org,
	lars@...afoo.de, robh@...nel.org, krzk+dt@...nel.org,
	conor+dt@...nel.org, ang.iglesiasg@...il.com,
	linus.walleij@...aro.org, biju.das.jz@...renesas.com,
	javier.carrasco.cruz@...il.com, semen.protsenko@...aro.org,
	579lpy@...il.com, ak@...klinger.de, linux-iio@...r.kernel.org,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
	christophe.jaillet@...adoo.fr
Subject: Re: [PATCH v4 6/7] iio: pressure: bmp280: Add data ready trigger
 support

On Thu, Aug 29, 2024 at 03:40:34PM +0300, Andy Shevchenko wrote:
> On Wed, Aug 28, 2024 at 10:51:26PM +0200, Vasileios Amoiridis wrote:
> > The BMP3xx and BMP5xx sensors have an interrupt pin which can be used as
> > a trigger for when there are data ready in the sensor for pick up.
> > 
> > This use case is used along with NORMAL_MODE in the sensor, which allows
> > the sensor to do consecutive measurements depending on the ODR rate value.
> > 
> > The trigger pin can be configured to be open-drain or push-pull and either
> > rising or falling edge.
> > 
> > No support is added yet for interrupts for FIFO, WATERMARK and out of range
> > values.
> 
> > Signed-off-by: Vasileios Amoiridis <vassilisamir@...il.com>
> > ---
> >  drivers/iio/pressure/bmp280-core.c | 231 ++++++++++++++++++++++++++++-
> >  drivers/iio/pressure/bmp280.h      |  21 +++
> >  2 files changed, 250 insertions(+), 2 deletions(-)
> 
> ...
> 
> > +static int __bmp280_trigger_probe(struct iio_dev *indio_dev,
> > +				  const struct iio_trigger_ops *trigger_ops,
> > +				  int (*int_config)(struct bmp280_data *data),
> > +				  irq_handler_t irq_thread_handler)
> > +{
> > +	struct bmp280_data *data = iio_priv(indio_dev);
> 
> With
> 
> 	struct device *dev = data->dev;
> 
> you may shorten some lines below and collapse a few.
> 

ACK.

> > +	struct fwnode_handle *fwnode;
> > +	int ret, irq, irq_type;
> 
> Why irq_type is signed?
> 

True, this can be made u32.

> Also try to make that returned variable is closer to the end of the definition
> block. And it might be worth to follow reversed xmas tree order (longer lines
> first).
> 
> > +	struct irq_data *desc;
> > +
> > +	irq = fwnode_irq_get(dev_fwnode(data->dev), 0);
> > +	if (irq < 0)
> > +		return dev_err_probe(data->dev, irq, "No interrupt found.\n");
> > +
> > +	desc = irq_get_irq_data(irq);
> > +	irq_type = irqd_get_trigger_type(desc);
> 
> So, altogether it may be written as
> 
> 	irq_type = irqd_get_trigger_type(irq_get_irq_data(irq));
> 
> And looking further, we have a helper for that:
> irq_get_trigger_type(). Why not use it?
> 

I was not aware of that, I can definitely change it.

> > +	switch (irq_type) {
> > +	case IRQF_TRIGGER_RISING:
> > +		data->trig_active_high = true;
> > +		break;
> > +	case IRQF_TRIGGER_FALLING:
> > +		data->trig_active_high = false;
> > +		break;
> > +	default:
> > +		return dev_err_probe(data->dev, -EINVAL,
> > +				     "Invalid interrupt type specified.\n");
> > +	}
> > +
> > +	data->trig_open_drain =
> > +		fwnode_property_read_bool(fwnode, "int-open-drain");
> > +
> > +	ret = int_config(data);
> > +	if (ret)
> > +		return ret;
> > +
> > +	data->trig = devm_iio_trigger_alloc(data->dev, "%s-dev%d",
> > +					    indio_dev->name,
> > +					    iio_device_id(indio_dev));
> > +	if (!data->trig)
> > +		return -ENOMEM;
> > +
> > +	data->trig->ops = trigger_ops;
> > +	iio_trigger_set_drvdata(data->trig, data);
> > +
> > +	ret = devm_request_threaded_irq(data->dev, irq, NULL,
> > +					irq_thread_handler, IRQF_ONESHOT,
> > +					indio_dev->name, indio_dev);
> > +	if (ret)
> > +		return dev_err_probe(data->dev, ret, "request irq failed.\n");
> > +
> > +	ret = devm_iio_trigger_register(data->dev, data->trig);
> > +	if (ret)
> > +		return dev_err_probe(data->dev, ret,
> > +				     "iio trigger register failed.\n");
> > +
> > +	indio_dev->trig = iio_trigger_get(data->trig);
> > +
> > +	return 0;
> > +}
> 
> ...
> 
> > +static int bmp380_int_config(struct bmp280_data *data)
> > +{
> > +	int pin_drive_cfg = FIELD_PREP(BMP380_INT_CTRL_OPEN_DRAIN,
> > +				       data->trig_open_drain);
> > +	int pin_level_cfg = FIELD_PREP(BMP380_INT_CTRL_LEVEL,
> > +				       data->trig_active_high);
> > +	int ret, int_cfg = pin_drive_cfg | pin_level_cfg;
> > +
> > +	ret = regmap_update_bits(data->regmap, BMP380_REG_INT_CONTROL,
> > +				 BMP380_INT_CTRL_SETTINGS_MASK, int_cfg);
> > +	if (ret) {
> > +		dev_err(data->dev, "Could not set interrupt settings\n");
> 
> > +		return ret;
> > +	}
> > +
> > +	return ret;
> 
> One of them is redundant or the last one should be return 0, but why not just
> leave one of them?
> 

I can just leave one of them, true!

> > +}
> 
> ...
> 
> > +static int bmp580_int_config(struct bmp280_data *data)
> > +{
> > +	int ret, int_cfg = FIELD_PREP(BMP580_INT_CONFIG_OPEN_DRAIN,
> > +				      data->trig_open_drain) |
> > +			   FIELD_PREP(BMP580_INT_CONFIG_LEVEL,
> > +				      data->trig_active_high);
> > +
> > +	ret = regmap_update_bits(data->regmap, BMP580_REG_INT_CONFIG,
> > +				 BMP580_INT_CONFIG_MASK, int_cfg);
> > +	if (ret) {
> > +		dev_err(data->dev, "Could not set interrupt settings\n");
> > +		return ret;
> > +	}
> > +
> > +	ret = regmap_set_bits(data->regmap, BMP580_REG_INT_SOURCE,
> > +			      BMP580_INT_SOURCE_DRDY);
> > +	if (ret) {
> > +		dev_err(data->dev, "Could not set interrupt source\n");
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> 
> So far you have three different styles in the same patch for this!
> Choose one and be consistent with it.
> 
> > +}
> 
> ...
> 
> > +	int (*trigger_probe)(struct iio_dev *indio_dev);
> >  	irqreturn_t (*trigger_handler)(int irq, void *p);
> 
> Yeah, at some point this can be changed to
> 
> 	irq_handler_t trigger_handler;
> 

I can definitely try that in a separate patch, thanks for pointing
all these out!

Cheers,
Vasilis

> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 

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