diff mbox series

[2/3] iio: adc: ad7887: convert driver to full DT probing

Message ID 20201117075254.4861-2-alexandru.ardelean@analog.com (mailing list archive)
State New
Headers show
Series [1/3] iio: adc: ad7887: convert dual-channel mode to DT/ACPI | expand

Commit Message

Alexandru Ardelean Nov. 17, 2020, 7:52 a.m. UTC
This change removes the SPI device table, adds an OF device table instead.
This should also be usable for ACPI via PRP0001.

This device is usually probed via device-tree, so it makes more sense to
use the OF device table.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
 drivers/iio/adc/ad7887.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

Comments

Jonathan Cameron Nov. 17, 2020, 11:01 a.m. UTC | #1
On Tue, 17 Nov 2020 09:52:53 +0200
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:

> This change removes the SPI device table, adds an OF device table instead.
> This should also be usable for ACPI via PRP0001.
> 
> This device is usually probed via device-tree, so it makes more sense to
> use the OF device table.
> 
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
So, we've had a few cases of having to put the device_id table
back again recently.
https://lore.kernel.org/linux-iio/20201101152613.2c37581a@archlinux/

They tend to be due to greybus doing it's probing in yet another fashion.
So far they've been all i2c devices, but I kind of assume it does the same for spi.
https://elixir.bootlin.com/linux/latest/source/drivers/staging/greybus/spilib.c#L437

How device_get_match_data() plays with that I'm not sure. It probably
doesn't right now given swnode doesn't have a device_get_match_data() callback.

https://elixir.bootlin.com/linux/latest/source/drivers/base/swnode.c#L539

So after all that I think I've argued myself around to thinking what you have
here is fine.  If someone wants to support this via a swnode then they can
figure out how to make that work.

+CC Vaishnav and Andy for their input.

Otherwise looks fine to me.

Thanks,

Jonathan


> ---
>  drivers/iio/adc/ad7887.c | 23 +++++++++++++++--------
>  1 file changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/iio/adc/ad7887.c b/drivers/iio/adc/ad7887.c
> index 06f684c053a0..4f68a1b17ec8 100644
> --- a/drivers/iio/adc/ad7887.c
> +++ b/drivers/iio/adc/ad7887.c
> @@ -40,6 +40,7 @@ enum ad7887_channels {
>  
>  /**
>   * struct ad7887_chip_info - chip specifc information
> + * @name:		the name of the part
>   * @int_vref_mv:	the internal reference voltage
>   * @channels:		channels specification
>   * @num_channels:	number of channels
> @@ -47,6 +48,7 @@ enum ad7887_channels {
>   * @num_dual_channels:	number of channels in dual mode
>   */
>  struct ad7887_chip_info {
> +	const char			*name;
>  	u16				int_vref_mv;
>  	const struct iio_chan_spec	*channels;
>  	unsigned int			num_channels;
> @@ -218,6 +220,7 @@ static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
>  	 * More devices added in future
>  	 */
>  	[ID_AD7887] = {
> +		.name = "ad7887",
>  		.channels = ad7887_channels,
>  		.num_channels = ARRAY_SIZE(ad7887_channels),
>  		.dual_channels = ad7887_dual_channels,
> @@ -239,12 +242,17 @@ static void ad7887_reg_disable(void *data)
>  
>  static int ad7887_probe(struct spi_device *spi)
>  {
> +	const struct ad7887_chip_info *info;
>  	struct ad7887_state *st;
>  	struct iio_dev *indio_dev;
>  	bool dual_mode;
>  	uint8_t mode;
>  	int ret;
>  
> +	info = device_get_match_data(&spi->dev);
> +	if (!info)
> +		return -ENODEV;
> +
>  	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
>  	if (indio_dev == NULL)
>  		return -ENOMEM;
> @@ -269,13 +277,12 @@ static int ad7887_probe(struct spi_device *spi)
>  			return ret;
>  	}
>  
> -	st->chip_info =
> -		&ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
> +	st->chip_info = info;
>  
>  	spi_set_drvdata(spi, indio_dev);
>  	st->spi = spi;
>  
> -	indio_dev->name = spi_get_device_id(spi)->name;
> +	indio_dev->name = st->chip_info->name;
>  	indio_dev->info = &ad7887_info;
>  	indio_dev->modes = INDIO_DIRECT_MODE;
>  
> @@ -336,18 +343,18 @@ static int ad7887_probe(struct spi_device *spi)
>  	return devm_iio_device_register(&spi->dev, indio_dev);
>  }
>  
> -static const struct spi_device_id ad7887_id[] = {
> -	{"ad7887", ID_AD7887},
> -	{}
> +static const struct of_device_id ad7887_of_match[] = {
> +	{ .compatible = "adi,ad7887", .data = &ad7887_chip_info_tbl[ID_AD7887] },
> +	{ }
>  };
> -MODULE_DEVICE_TABLE(spi, ad7887_id);
> +MODULE_DEVICE_TABLE(of, ad7887_of_match);
>  
>  static struct spi_driver ad7887_driver = {
>  	.driver = {
>  		.name	= "ad7887",
> +		.of_match_table	= ad7887_of_match,
>  	},
>  	.probe		= ad7887_probe,
> -	.id_table	= ad7887_id,
>  };
>  module_spi_driver(ad7887_driver);
>
Jonathan Cameron Nov. 17, 2020, 11:04 a.m. UTC | #2
On Tue, 17 Nov 2020 11:01:11 +0000
Jonathan Cameron <Jonathan.Cameron@Huawei.com> wrote:

> On Tue, 17 Nov 2020 09:52:53 +0200
> Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:
> 
> > This change removes the SPI device table, adds an OF device table instead.
> > This should also be usable for ACPI via PRP0001.
> > 
> > This device is usually probed via device-tree, so it makes more sense to
> > use the OF device table.
> > 
> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>  
> So, we've had a few cases of having to put the device_id table
> back again recently.
> https://lore.kernel.org/linux-iio/20201101152613.2c37581a@archlinux/
> 
> They tend to be due to greybus doing it's probing in yet another fashion.
> So far they've been all i2c devices, but I kind of assume it does the same for spi.
> https://elixir.bootlin.com/linux/latest/source/drivers/staging/greybus/spilib.c#L437
> 
> How device_get_match_data() plays with that I'm not sure. It probably
> doesn't right now given swnode doesn't have a device_get_match_data() callback.
> 
> https://elixir.bootlin.com/linux/latest/source/drivers/base/swnode.c#L539
> 
> So after all that I think I've argued myself around to thinking what you have
> here is fine.  If someone wants to support this via a swnode then they can
> figure out how to make that work.
> 
> +CC Vaishnav and Andy for their input.
> 
> Otherwise looks fine to me.

Having said that.... Why are we going through this dance for driver with
only one compatible?   Are there other parts on their way?
If not, perhaps we should just rip out the matching code entirely in
the interests of simplicity.

Jonathan

> 
> Thanks,
> 
> Jonathan
> 
> 
> > ---
> >  drivers/iio/adc/ad7887.c | 23 +++++++++++++++--------
> >  1 file changed, 15 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/iio/adc/ad7887.c b/drivers/iio/adc/ad7887.c
> > index 06f684c053a0..4f68a1b17ec8 100644
> > --- a/drivers/iio/adc/ad7887.c
> > +++ b/drivers/iio/adc/ad7887.c
> > @@ -40,6 +40,7 @@ enum ad7887_channels {
> >  
> >  /**
> >   * struct ad7887_chip_info - chip specifc information
> > + * @name:		the name of the part
> >   * @int_vref_mv:	the internal reference voltage
> >   * @channels:		channels specification
> >   * @num_channels:	number of channels
> > @@ -47,6 +48,7 @@ enum ad7887_channels {
> >   * @num_dual_channels:	number of channels in dual mode
> >   */
> >  struct ad7887_chip_info {
> > +	const char			*name;
> >  	u16				int_vref_mv;
> >  	const struct iio_chan_spec	*channels;
> >  	unsigned int			num_channels;
> > @@ -218,6 +220,7 @@ static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
> >  	 * More devices added in future
> >  	 */
> >  	[ID_AD7887] = {
> > +		.name = "ad7887",
> >  		.channels = ad7887_channels,
> >  		.num_channels = ARRAY_SIZE(ad7887_channels),
> >  		.dual_channels = ad7887_dual_channels,
> > @@ -239,12 +242,17 @@ static void ad7887_reg_disable(void *data)
> >  
> >  static int ad7887_probe(struct spi_device *spi)
> >  {
> > +	const struct ad7887_chip_info *info;
> >  	struct ad7887_state *st;
> >  	struct iio_dev *indio_dev;
> >  	bool dual_mode;
> >  	uint8_t mode;
> >  	int ret;
> >  
> > +	info = device_get_match_data(&spi->dev);
> > +	if (!info)
> > +		return -ENODEV;
> > +
> >  	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> >  	if (indio_dev == NULL)
> >  		return -ENOMEM;
> > @@ -269,13 +277,12 @@ static int ad7887_probe(struct spi_device *spi)
> >  			return ret;
> >  	}
> >  
> > -	st->chip_info =
> > -		&ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
> > +	st->chip_info = info;
> >  
> >  	spi_set_drvdata(spi, indio_dev);
> >  	st->spi = spi;
> >  
> > -	indio_dev->name = spi_get_device_id(spi)->name;
> > +	indio_dev->name = st->chip_info->name;
> >  	indio_dev->info = &ad7887_info;
> >  	indio_dev->modes = INDIO_DIRECT_MODE;
> >  
> > @@ -336,18 +343,18 @@ static int ad7887_probe(struct spi_device *spi)
> >  	return devm_iio_device_register(&spi->dev, indio_dev);
> >  }
> >  
> > -static const struct spi_device_id ad7887_id[] = {
> > -	{"ad7887", ID_AD7887},
> > -	{}
> > +static const struct of_device_id ad7887_of_match[] = {
> > +	{ .compatible = "adi,ad7887", .data = &ad7887_chip_info_tbl[ID_AD7887] },
> > +	{ }
> >  };
> > -MODULE_DEVICE_TABLE(spi, ad7887_id);
> > +MODULE_DEVICE_TABLE(of, ad7887_of_match);
> >  
> >  static struct spi_driver ad7887_driver = {
> >  	.driver = {
> >  		.name	= "ad7887",
> > +		.of_match_table	= ad7887_of_match,
> >  	},
> >  	.probe		= ad7887_probe,
> > -	.id_table	= ad7887_id,
> >  };
> >  module_spi_driver(ad7887_driver);
> >    
>
Andy Shevchenko Nov. 17, 2020, 11:05 a.m. UTC | #3
On Tue, Nov 17, 2020 at 1:01 PM Jonathan Cameron
<Jonathan.Cameron@huawei.com> wrote:
>
> On Tue, 17 Nov 2020 09:52:53 +0200
> Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:
>
> > This change removes the SPI device table, adds an OF device table instead.
> > This should also be usable for ACPI via PRP0001.
> >
> > This device is usually probed via device-tree, so it makes more sense to
> > use the OF device table.
> >
> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> So, we've had a few cases of having to put the device_id table
> back again recently.
> https://lore.kernel.org/linux-iio/20201101152613.2c37581a@archlinux/
>
> They tend to be due to greybus doing it's probing in yet another fashion.
> So far they've been all i2c devices, but I kind of assume it does the same for spi.
> https://elixir.bootlin.com/linux/latest/source/drivers/staging/greybus/spilib.c#L437
>
> How device_get_match_data() plays with that I'm not sure. It probably
> doesn't right now given swnode doesn't have a device_get_match_data() callback.
>
> https://elixir.bootlin.com/linux/latest/source/drivers/base/swnode.c#L539
>
> So after all that I think I've argued myself around to thinking what you have
> here is fine.  If someone wants to support this via a swnode then they can
> figure out how to make that work.
>
> +CC Vaishnav and Andy for their input.

device_get_match_data() doesn't know about bus type specifics. One may
introduce a helper like

const void *spi_device_get_match_data(dev)
{
  const void *match = device_get_match_data(dev);
  if (match)
    return match;
  return spi_dev_id....;
}

And use it with the SPI ID table.
Alexandru Ardelean Nov. 17, 2020, 3:03 p.m. UTC | #4
On Tue, Nov 17, 2020 at 1:06 PM Jonathan Cameron
<Jonathan.Cameron@huawei.com> wrote:
>
> On Tue, 17 Nov 2020 11:01:11 +0000
> Jonathan Cameron <Jonathan.Cameron@Huawei.com> wrote:
>
> > On Tue, 17 Nov 2020 09:52:53 +0200
> > Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:
> >
> > > This change removes the SPI device table, adds an OF device table instead.
> > > This should also be usable for ACPI via PRP0001.
> > >
> > > This device is usually probed via device-tree, so it makes more sense to
> > > use the OF device table.
> > >
> > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> > So, we've had a few cases of having to put the device_id table
> > back again recently.
> > https://lore.kernel.org/linux-iio/20201101152613.2c37581a@archlinux/
> >
> > They tend to be due to greybus doing it's probing in yet another fashion.
> > So far they've been all i2c devices, but I kind of assume it does the same for spi.
> > https://elixir.bootlin.com/linux/latest/source/drivers/staging/greybus/spilib.c#L437
> >
> > How device_get_match_data() plays with that I'm not sure. It probably
> > doesn't right now given swnode doesn't have a device_get_match_data() callback.
> >
> > https://elixir.bootlin.com/linux/latest/source/drivers/base/swnode.c#L539
> >
> > So after all that I think I've argued myself around to thinking what you have
> > here is fine.  If someone wants to support this via a swnode then they can
> > figure out how to make that work.
> >
> > +CC Vaishnav and Andy for their input.
> >
> > Otherwise looks fine to me.
>
> Having said that.... Why are we going through this dance for driver with
> only one compatible?   Are there other parts on their way?
> If not, perhaps we should just rip out the matching code entirely in
> the interests of simplicity.

So, this one has a bit of a funny story.
There's an AD7888 which is similar in terms of registers but with more channels.
Lars did a patch to support it on top of AD7887:
    https://github.com/analogdevicesinc/linux/commits/iio-ad7888

We tried to order a part for this to test the changes, but we got a
reply that it's obsolete.
The website says it is still in production.
So, I was confused about the answer we got. ¯\_(ツ)_/¯

In the meantime, I thought I'd take some of the cleanup value of Lars'
work and do the cleanup only.
We may still find that part somewhere and maybe add it, or maybe
another one would come along.
I don't know at this point. I'm mostly looking at some of my backlog
stuff and trying to cleanup old stuff.

I'm fine to simplify the driver now and add the matching bits later.

>
> Jonathan
>
> >
> > Thanks,
> >
> > Jonathan
> >
> >
> > > ---
> > >  drivers/iio/adc/ad7887.c | 23 +++++++++++++++--------
> > >  1 file changed, 15 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/drivers/iio/adc/ad7887.c b/drivers/iio/adc/ad7887.c
> > > index 06f684c053a0..4f68a1b17ec8 100644
> > > --- a/drivers/iio/adc/ad7887.c
> > > +++ b/drivers/iio/adc/ad7887.c
> > > @@ -40,6 +40,7 @@ enum ad7887_channels {
> > >
> > >  /**
> > >   * struct ad7887_chip_info - chip specifc information
> > > + * @name:          the name of the part
> > >   * @int_vref_mv:   the internal reference voltage
> > >   * @channels:              channels specification
> > >   * @num_channels:  number of channels
> > > @@ -47,6 +48,7 @@ enum ad7887_channels {
> > >   * @num_dual_channels:     number of channels in dual mode
> > >   */
> > >  struct ad7887_chip_info {
> > > +   const char                      *name;
> > >     u16                             int_vref_mv;
> > >     const struct iio_chan_spec      *channels;
> > >     unsigned int                    num_channels;
> > > @@ -218,6 +220,7 @@ static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
> > >      * More devices added in future
> > >      */
> > >     [ID_AD7887] = {
> > > +           .name = "ad7887",
> > >             .channels = ad7887_channels,
> > >             .num_channels = ARRAY_SIZE(ad7887_channels),
> > >             .dual_channels = ad7887_dual_channels,
> > > @@ -239,12 +242,17 @@ static void ad7887_reg_disable(void *data)
> > >
> > >  static int ad7887_probe(struct spi_device *spi)
> > >  {
> > > +   const struct ad7887_chip_info *info;
> > >     struct ad7887_state *st;
> > >     struct iio_dev *indio_dev;
> > >     bool dual_mode;
> > >     uint8_t mode;
> > >     int ret;
> > >
> > > +   info = device_get_match_data(&spi->dev);
> > > +   if (!info)
> > > +           return -ENODEV;
> > > +
> > >     indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> > >     if (indio_dev == NULL)
> > >             return -ENOMEM;
> > > @@ -269,13 +277,12 @@ static int ad7887_probe(struct spi_device *spi)
> > >                     return ret;
> > >     }
> > >
> > > -   st->chip_info =
> > > -           &ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
> > > +   st->chip_info = info;
> > >
> > >     spi_set_drvdata(spi, indio_dev);
> > >     st->spi = spi;
> > >
> > > -   indio_dev->name = spi_get_device_id(spi)->name;
> > > +   indio_dev->name = st->chip_info->name;
> > >     indio_dev->info = &ad7887_info;
> > >     indio_dev->modes = INDIO_DIRECT_MODE;
> > >
> > > @@ -336,18 +343,18 @@ static int ad7887_probe(struct spi_device *spi)
> > >     return devm_iio_device_register(&spi->dev, indio_dev);
> > >  }
> > >
> > > -static const struct spi_device_id ad7887_id[] = {
> > > -   {"ad7887", ID_AD7887},
> > > -   {}
> > > +static const struct of_device_id ad7887_of_match[] = {
> > > +   { .compatible = "adi,ad7887", .data = &ad7887_chip_info_tbl[ID_AD7887] },
> > > +   { }
> > >  };
> > > -MODULE_DEVICE_TABLE(spi, ad7887_id);
> > > +MODULE_DEVICE_TABLE(of, ad7887_of_match);
> > >
> > >  static struct spi_driver ad7887_driver = {
> > >     .driver = {
> > >             .name   = "ad7887",
> > > +           .of_match_table = ad7887_of_match,
> > >     },
> > >     .probe          = ad7887_probe,
> > > -   .id_table       = ad7887_id,
> > >  };
> > >  module_spi_driver(ad7887_driver);
> > >
> >
>
Jonathan Cameron Nov. 17, 2020, 4:02 p.m. UTC | #5
On Tue, 17 Nov 2020 17:03:06 +0200
Alexandru Ardelean <ardeleanalex@gmail.com> wrote:

> On Tue, Nov 17, 2020 at 1:06 PM Jonathan Cameron
> <Jonathan.Cameron@huawei.com> wrote:
> >
> > On Tue, 17 Nov 2020 11:01:11 +0000
> > Jonathan Cameron <Jonathan.Cameron@Huawei.com> wrote:
> >  
> > > On Tue, 17 Nov 2020 09:52:53 +0200
> > > Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:
> > >  
> > > > This change removes the SPI device table, adds an OF device table instead.
> > > > This should also be usable for ACPI via PRP0001.
> > > >
> > > > This device is usually probed via device-tree, so it makes more sense to
> > > > use the OF device table.
> > > >
> > > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>  
> > > So, we've had a few cases of having to put the device_id table
> > > back again recently.
> > > https://lore.kernel.org/linux-iio/20201101152613.2c37581a@archlinux/
> > >
> > > They tend to be due to greybus doing it's probing in yet another fashion.
> > > So far they've been all i2c devices, but I kind of assume it does the same for spi.
> > > https://elixir.bootlin.com/linux/latest/source/drivers/staging/greybus/spilib.c#L437
> > >
> > > How device_get_match_data() plays with that I'm not sure. It probably
> > > doesn't right now given swnode doesn't have a device_get_match_data() callback.
> > >
> > > https://elixir.bootlin.com/linux/latest/source/drivers/base/swnode.c#L539
> > >
> > > So after all that I think I've argued myself around to thinking what you have
> > > here is fine.  If someone wants to support this via a swnode then they can
> > > figure out how to make that work.
> > >
> > > +CC Vaishnav and Andy for their input.
> > >
> > > Otherwise looks fine to me.  
> >
> > Having said that.... Why are we going through this dance for driver with
> > only one compatible?   Are there other parts on their way?
> > If not, perhaps we should just rip out the matching code entirely in
> > the interests of simplicity.  
> 
> So, this one has a bit of a funny story.
> There's an AD7888 which is similar in terms of registers but with more channels.
> Lars did a patch to support it on top of AD7887:
>     https://github.com/analogdevicesinc/linux/commits/iio-ad7888
> 
> We tried to order a part for this to test the changes, but we got a
> reply that it's obsolete.
> The website says it is still in production.
> So, I was confused about the answer we got. ¯\_(ツ)_/¯
> 
> In the meantime, I thought I'd take some of the cleanup value of Lars'
> work and do the cleanup only.
> We may still find that part somewhere and maybe add it, or maybe
> another one would come along.
> I don't know at this point. I'm mostly looking at some of my backlog
> stuff and trying to cleanup old stuff.
> 
> I'm fine to simplify the driver now and add the matching bits later.

Sounds good to me.

> 
> >
> > Jonathan
> >  
> > >
> > > Thanks,
> > >
> > > Jonathan
> > >
> > >  
> > > > ---
> > > >  drivers/iio/adc/ad7887.c | 23 +++++++++++++++--------
> > > >  1 file changed, 15 insertions(+), 8 deletions(-)
> > > >
> > > > diff --git a/drivers/iio/adc/ad7887.c b/drivers/iio/adc/ad7887.c
> > > > index 06f684c053a0..4f68a1b17ec8 100644
> > > > --- a/drivers/iio/adc/ad7887.c
> > > > +++ b/drivers/iio/adc/ad7887.c
> > > > @@ -40,6 +40,7 @@ enum ad7887_channels {
> > > >
> > > >  /**
> > > >   * struct ad7887_chip_info - chip specifc information
> > > > + * @name:          the name of the part
> > > >   * @int_vref_mv:   the internal reference voltage
> > > >   * @channels:              channels specification
> > > >   * @num_channels:  number of channels
> > > > @@ -47,6 +48,7 @@ enum ad7887_channels {
> > > >   * @num_dual_channels:     number of channels in dual mode
> > > >   */
> > > >  struct ad7887_chip_info {
> > > > +   const char                      *name;
> > > >     u16                             int_vref_mv;
> > > >     const struct iio_chan_spec      *channels;
> > > >     unsigned int                    num_channels;
> > > > @@ -218,6 +220,7 @@ static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
> > > >      * More devices added in future
> > > >      */
> > > >     [ID_AD7887] = {
> > > > +           .name = "ad7887",
> > > >             .channels = ad7887_channels,
> > > >             .num_channels = ARRAY_SIZE(ad7887_channels),
> > > >             .dual_channels = ad7887_dual_channels,
> > > > @@ -239,12 +242,17 @@ static void ad7887_reg_disable(void *data)
> > > >
> > > >  static int ad7887_probe(struct spi_device *spi)
> > > >  {
> > > > +   const struct ad7887_chip_info *info;
> > > >     struct ad7887_state *st;
> > > >     struct iio_dev *indio_dev;
> > > >     bool dual_mode;
> > > >     uint8_t mode;
> > > >     int ret;
> > > >
> > > > +   info = device_get_match_data(&spi->dev);
> > > > +   if (!info)
> > > > +           return -ENODEV;
> > > > +
> > > >     indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> > > >     if (indio_dev == NULL)
> > > >             return -ENOMEM;
> > > > @@ -269,13 +277,12 @@ static int ad7887_probe(struct spi_device *spi)
> > > >                     return ret;
> > > >     }
> > > >
> > > > -   st->chip_info =
> > > > -           &ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
> > > > +   st->chip_info = info;
> > > >
> > > >     spi_set_drvdata(spi, indio_dev);
> > > >     st->spi = spi;
> > > >
> > > > -   indio_dev->name = spi_get_device_id(spi)->name;
> > > > +   indio_dev->name = st->chip_info->name;
> > > >     indio_dev->info = &ad7887_info;
> > > >     indio_dev->modes = INDIO_DIRECT_MODE;
> > > >
> > > > @@ -336,18 +343,18 @@ static int ad7887_probe(struct spi_device *spi)
> > > >     return devm_iio_device_register(&spi->dev, indio_dev);
> > > >  }
> > > >
> > > > -static const struct spi_device_id ad7887_id[] = {
> > > > -   {"ad7887", ID_AD7887},
> > > > -   {}
> > > > +static const struct of_device_id ad7887_of_match[] = {
> > > > +   { .compatible = "adi,ad7887", .data = &ad7887_chip_info_tbl[ID_AD7887] },
> > > > +   { }
> > > >  };
> > > > -MODULE_DEVICE_TABLE(spi, ad7887_id);
> > > > +MODULE_DEVICE_TABLE(of, ad7887_of_match);
> > > >
> > > >  static struct spi_driver ad7887_driver = {
> > > >     .driver = {
> > > >             .name   = "ad7887",
> > > > +           .of_match_table = ad7887_of_match,
> > > >     },
> > > >     .probe          = ad7887_probe,
> > > > -   .id_table       = ad7887_id,
> > > >  };
> > > >  module_spi_driver(ad7887_driver);
> > > >  
> > >  
> >
Alexandru Ardelean Nov. 18, 2020, 12:59 p.m. UTC | #6
On Tue, Nov 17, 2020 at 6:02 PM Jonathan Cameron
<Jonathan.Cameron@huawei.com> wrote:
>
> On Tue, 17 Nov 2020 17:03:06 +0200
> Alexandru Ardelean <ardeleanalex@gmail.com> wrote:
>
> > On Tue, Nov 17, 2020 at 1:06 PM Jonathan Cameron
> > <Jonathan.Cameron@huawei.com> wrote:
> > >
> > > On Tue, 17 Nov 2020 11:01:11 +0000
> > > Jonathan Cameron <Jonathan.Cameron@Huawei.com> wrote:
> > >
> > > > On Tue, 17 Nov 2020 09:52:53 +0200
> > > > Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:
> > > >
> > > > > This change removes the SPI device table, adds an OF device table instead.
> > > > > This should also be usable for ACPI via PRP0001.
> > > > >
> > > > > This device is usually probed via device-tree, so it makes more sense to
> > > > > use the OF device table.
> > > > >
> > > > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> > > > So, we've had a few cases of having to put the device_id table
> > > > back again recently.
> > > > https://lore.kernel.org/linux-iio/20201101152613.2c37581a@archlinux/
> > > >
> > > > They tend to be due to greybus doing it's probing in yet another fashion.
> > > > So far they've been all i2c devices, but I kind of assume it does the same for spi.
> > > > https://elixir.bootlin.com/linux/latest/source/drivers/staging/greybus/spilib.c#L437
> > > >
> > > > How device_get_match_data() plays with that I'm not sure. It probably
> > > > doesn't right now given swnode doesn't have a device_get_match_data() callback.
> > > >
> > > > https://elixir.bootlin.com/linux/latest/source/drivers/base/swnode.c#L539
> > > >
> > > > So after all that I think I've argued myself around to thinking what you have
> > > > here is fine.  If someone wants to support this via a swnode then they can
> > > > figure out how to make that work.
> > > >
> > > > +CC Vaishnav and Andy for their input.
> > > >
> > > > Otherwise looks fine to me.
> > >
> > > Having said that.... Why are we going through this dance for driver with
> > > only one compatible?   Are there other parts on their way?
> > > If not, perhaps we should just rip out the matching code entirely in
> > > the interests of simplicity.
> >
> > So, this one has a bit of a funny story.
> > There's an AD7888 which is similar in terms of registers but with more channels.
> > Lars did a patch to support it on top of AD7887:
> >     https://github.com/analogdevicesinc/linux/commits/iio-ad7888
> >
> > We tried to order a part for this to test the changes, but we got a
> > reply that it's obsolete.
> > The website says it is still in production.
> > So, I was confused about the answer we got. ¯\_(ツ)_/¯
> >
> > In the meantime, I thought I'd take some of the cleanup value of Lars'
> > work and do the cleanup only.
> > We may still find that part somewhere and maybe add it, or maybe
> > another one would come along.
> > I don't know at this point. I'm mostly looking at some of my backlog
> > stuff and trying to cleanup old stuff.
> >
> > I'm fine to simplify the driver now and add the matching bits later.
>
> Sounds good to me.

I'm a bit vague on the message of this reply.
Should I simplify it or leave it as-is?

>
> >
> > >
> > > Jonathan
> > >
> > > >
> > > > Thanks,
> > > >
> > > > Jonathan
> > > >
> > > >
> > > > > ---
> > > > >  drivers/iio/adc/ad7887.c | 23 +++++++++++++++--------
> > > > >  1 file changed, 15 insertions(+), 8 deletions(-)
> > > > >
> > > > > diff --git a/drivers/iio/adc/ad7887.c b/drivers/iio/adc/ad7887.c
> > > > > index 06f684c053a0..4f68a1b17ec8 100644
> > > > > --- a/drivers/iio/adc/ad7887.c
> > > > > +++ b/drivers/iio/adc/ad7887.c
> > > > > @@ -40,6 +40,7 @@ enum ad7887_channels {
> > > > >
> > > > >  /**
> > > > >   * struct ad7887_chip_info - chip specifc information
> > > > > + * @name:          the name of the part
> > > > >   * @int_vref_mv:   the internal reference voltage
> > > > >   * @channels:              channels specification
> > > > >   * @num_channels:  number of channels
> > > > > @@ -47,6 +48,7 @@ enum ad7887_channels {
> > > > >   * @num_dual_channels:     number of channels in dual mode
> > > > >   */
> > > > >  struct ad7887_chip_info {
> > > > > +   const char                      *name;
> > > > >     u16                             int_vref_mv;
> > > > >     const struct iio_chan_spec      *channels;
> > > > >     unsigned int                    num_channels;
> > > > > @@ -218,6 +220,7 @@ static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
> > > > >      * More devices added in future
> > > > >      */
> > > > >     [ID_AD7887] = {
> > > > > +           .name = "ad7887",
> > > > >             .channels = ad7887_channels,
> > > > >             .num_channels = ARRAY_SIZE(ad7887_channels),
> > > > >             .dual_channels = ad7887_dual_channels,
> > > > > @@ -239,12 +242,17 @@ static void ad7887_reg_disable(void *data)
> > > > >
> > > > >  static int ad7887_probe(struct spi_device *spi)
> > > > >  {
> > > > > +   const struct ad7887_chip_info *info;
> > > > >     struct ad7887_state *st;
> > > > >     struct iio_dev *indio_dev;
> > > > >     bool dual_mode;
> > > > >     uint8_t mode;
> > > > >     int ret;
> > > > >
> > > > > +   info = device_get_match_data(&spi->dev);
> > > > > +   if (!info)
> > > > > +           return -ENODEV;
> > > > > +
> > > > >     indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> > > > >     if (indio_dev == NULL)
> > > > >             return -ENOMEM;
> > > > > @@ -269,13 +277,12 @@ static int ad7887_probe(struct spi_device *spi)
> > > > >                     return ret;
> > > > >     }
> > > > >
> > > > > -   st->chip_info =
> > > > > -           &ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
> > > > > +   st->chip_info = info;
> > > > >
> > > > >     spi_set_drvdata(spi, indio_dev);
> > > > >     st->spi = spi;
> > > > >
> > > > > -   indio_dev->name = spi_get_device_id(spi)->name;
> > > > > +   indio_dev->name = st->chip_info->name;
> > > > >     indio_dev->info = &ad7887_info;
> > > > >     indio_dev->modes = INDIO_DIRECT_MODE;
> > > > >
> > > > > @@ -336,18 +343,18 @@ static int ad7887_probe(struct spi_device *spi)
> > > > >     return devm_iio_device_register(&spi->dev, indio_dev);
> > > > >  }
> > > > >
> > > > > -static const struct spi_device_id ad7887_id[] = {
> > > > > -   {"ad7887", ID_AD7887},
> > > > > -   {}
> > > > > +static const struct of_device_id ad7887_of_match[] = {
> > > > > +   { .compatible = "adi,ad7887", .data = &ad7887_chip_info_tbl[ID_AD7887] },
> > > > > +   { }
> > > > >  };
> > > > > -MODULE_DEVICE_TABLE(spi, ad7887_id);
> > > > > +MODULE_DEVICE_TABLE(of, ad7887_of_match);
> > > > >
> > > > >  static struct spi_driver ad7887_driver = {
> > > > >     .driver = {
> > > > >             .name   = "ad7887",
> > > > > +           .of_match_table = ad7887_of_match,
> > > > >     },
> > > > >     .probe          = ad7887_probe,
> > > > > -   .id_table       = ad7887_id,
> > > > >  };
> > > > >  module_spi_driver(ad7887_driver);
> > > > >
> > > >
> > >
>
Jonathan Cameron Nov. 18, 2020, 4:06 p.m. UTC | #7
On Wed, 18 Nov 2020 14:59:39 +0200
Alexandru Ardelean <ardeleanalex@gmail.com> wrote:

> On Tue, Nov 17, 2020 at 6:02 PM Jonathan Cameron
> <Jonathan.Cameron@huawei.com> wrote:
> >
> > On Tue, 17 Nov 2020 17:03:06 +0200
> > Alexandru Ardelean <ardeleanalex@gmail.com> wrote:
> >  
> > > On Tue, Nov 17, 2020 at 1:06 PM Jonathan Cameron
> > > <Jonathan.Cameron@huawei.com> wrote:  
> > > >
> > > > On Tue, 17 Nov 2020 11:01:11 +0000
> > > > Jonathan Cameron <Jonathan.Cameron@Huawei.com> wrote:
> > > >  
> > > > > On Tue, 17 Nov 2020 09:52:53 +0200
> > > > > Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:
> > > > >  
> > > > > > This change removes the SPI device table, adds an OF device table instead.
> > > > > > This should also be usable for ACPI via PRP0001.
> > > > > >
> > > > > > This device is usually probed via device-tree, so it makes more sense to
> > > > > > use the OF device table.
> > > > > >
> > > > > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>  
> > > > > So, we've had a few cases of having to put the device_id table
> > > > > back again recently.
> > > > > https://lore.kernel.org/linux-iio/20201101152613.2c37581a@archlinux/
> > > > >
> > > > > They tend to be due to greybus doing it's probing in yet another fashion.
> > > > > So far they've been all i2c devices, but I kind of assume it does the same for spi.
> > > > > https://elixir.bootlin.com/linux/latest/source/drivers/staging/greybus/spilib.c#L437
> > > > >
> > > > > How device_get_match_data() plays with that I'm not sure. It probably
> > > > > doesn't right now given swnode doesn't have a device_get_match_data() callback.
> > > > >
> > > > > https://elixir.bootlin.com/linux/latest/source/drivers/base/swnode.c#L539
> > > > >
> > > > > So after all that I think I've argued myself around to thinking what you have
> > > > > here is fine.  If someone wants to support this via a swnode then they can
> > > > > figure out how to make that work.
> > > > >
> > > > > +CC Vaishnav and Andy for their input.
> > > > >
> > > > > Otherwise looks fine to me.  
> > > >
> > > > Having said that.... Why are we going through this dance for driver with
> > > > only one compatible?   Are there other parts on their way?
> > > > If not, perhaps we should just rip out the matching code entirely in
> > > > the interests of simplicity.  
> > >
> > > So, this one has a bit of a funny story.
> > > There's an AD7888 which is similar in terms of registers but with more channels.
> > > Lars did a patch to support it on top of AD7887:
> > >     https://github.com/analogdevicesinc/linux/commits/iio-ad7888
> > >
> > > We tried to order a part for this to test the changes, but we got a
> > > reply that it's obsolete.
> > > The website says it is still in production.
> > > So, I was confused about the answer we got. ¯\_(ツ)_/¯
> > >
> > > In the meantime, I thought I'd take some of the cleanup value of Lars'
> > > work and do the cleanup only.
> > > We may still find that part somewhere and maybe add it, or maybe
> > > another one would come along.
> > > I don't know at this point. I'm mostly looking at some of my backlog
> > > stuff and trying to cleanup old stuff.
> > >
> > > I'm fine to simplify the driver now and add the matching bits later.  
> >
> > Sounds good to me.  
> 
> I'm a bit vague on the message of this reply.
> Should I simplify it or leave it as-is?
oops.  Simplify it as then we don't have to worry about dealing with the
greybus case.

Jonathan

> 
> >  
> > >  
> > > >
> > > > Jonathan
> > > >  
> > > > >
> > > > > Thanks,
> > > > >
> > > > > Jonathan
> > > > >
> > > > >  
> > > > > > ---
> > > > > >  drivers/iio/adc/ad7887.c | 23 +++++++++++++++--------
> > > > > >  1 file changed, 15 insertions(+), 8 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/iio/adc/ad7887.c b/drivers/iio/adc/ad7887.c
> > > > > > index 06f684c053a0..4f68a1b17ec8 100644
> > > > > > --- a/drivers/iio/adc/ad7887.c
> > > > > > +++ b/drivers/iio/adc/ad7887.c
> > > > > > @@ -40,6 +40,7 @@ enum ad7887_channels {
> > > > > >
> > > > > >  /**
> > > > > >   * struct ad7887_chip_info - chip specifc information
> > > > > > + * @name:          the name of the part
> > > > > >   * @int_vref_mv:   the internal reference voltage
> > > > > >   * @channels:              channels specification
> > > > > >   * @num_channels:  number of channels
> > > > > > @@ -47,6 +48,7 @@ enum ad7887_channels {
> > > > > >   * @num_dual_channels:     number of channels in dual mode
> > > > > >   */
> > > > > >  struct ad7887_chip_info {
> > > > > > +   const char                      *name;
> > > > > >     u16                             int_vref_mv;
> > > > > >     const struct iio_chan_spec      *channels;
> > > > > >     unsigned int                    num_channels;
> > > > > > @@ -218,6 +220,7 @@ static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
> > > > > >      * More devices added in future
> > > > > >      */
> > > > > >     [ID_AD7887] = {
> > > > > > +           .name = "ad7887",
> > > > > >             .channels = ad7887_channels,
> > > > > >             .num_channels = ARRAY_SIZE(ad7887_channels),
> > > > > >             .dual_channels = ad7887_dual_channels,
> > > > > > @@ -239,12 +242,17 @@ static void ad7887_reg_disable(void *data)
> > > > > >
> > > > > >  static int ad7887_probe(struct spi_device *spi)
> > > > > >  {
> > > > > > +   const struct ad7887_chip_info *info;
> > > > > >     struct ad7887_state *st;
> > > > > >     struct iio_dev *indio_dev;
> > > > > >     bool dual_mode;
> > > > > >     uint8_t mode;
> > > > > >     int ret;
> > > > > >
> > > > > > +   info = device_get_match_data(&spi->dev);
> > > > > > +   if (!info)
> > > > > > +           return -ENODEV;
> > > > > > +
> > > > > >     indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> > > > > >     if (indio_dev == NULL)
> > > > > >             return -ENOMEM;
> > > > > > @@ -269,13 +277,12 @@ static int ad7887_probe(struct spi_device *spi)
> > > > > >                     return ret;
> > > > > >     }
> > > > > >
> > > > > > -   st->chip_info =
> > > > > > -           &ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
> > > > > > +   st->chip_info = info;
> > > > > >
> > > > > >     spi_set_drvdata(spi, indio_dev);
> > > > > >     st->spi = spi;
> > > > > >
> > > > > > -   indio_dev->name = spi_get_device_id(spi)->name;
> > > > > > +   indio_dev->name = st->chip_info->name;
> > > > > >     indio_dev->info = &ad7887_info;
> > > > > >     indio_dev->modes = INDIO_DIRECT_MODE;
> > > > > >
> > > > > > @@ -336,18 +343,18 @@ static int ad7887_probe(struct spi_device *spi)
> > > > > >     return devm_iio_device_register(&spi->dev, indio_dev);
> > > > > >  }
> > > > > >
> > > > > > -static const struct spi_device_id ad7887_id[] = {
> > > > > > -   {"ad7887", ID_AD7887},
> > > > > > -   {}
> > > > > > +static const struct of_device_id ad7887_of_match[] = {
> > > > > > +   { .compatible = "adi,ad7887", .data = &ad7887_chip_info_tbl[ID_AD7887] },
> > > > > > +   { }
> > > > > >  };
> > > > > > -MODULE_DEVICE_TABLE(spi, ad7887_id);
> > > > > > +MODULE_DEVICE_TABLE(of, ad7887_of_match);
> > > > > >
> > > > > >  static struct spi_driver ad7887_driver = {
> > > > > >     .driver = {
> > > > > >             .name   = "ad7887",
> > > > > > +           .of_match_table = ad7887_of_match,
> > > > > >     },
> > > > > >     .probe          = ad7887_probe,
> > > > > > -   .id_table       = ad7887_id,
> > > > > >  };
> > > > > >  module_spi_driver(ad7887_driver);
> > > > > >  
> > > > >  
> > > >  
> >
diff mbox series

Patch

diff --git a/drivers/iio/adc/ad7887.c b/drivers/iio/adc/ad7887.c
index 06f684c053a0..4f68a1b17ec8 100644
--- a/drivers/iio/adc/ad7887.c
+++ b/drivers/iio/adc/ad7887.c
@@ -40,6 +40,7 @@  enum ad7887_channels {
 
 /**
  * struct ad7887_chip_info - chip specifc information
+ * @name:		the name of the part
  * @int_vref_mv:	the internal reference voltage
  * @channels:		channels specification
  * @num_channels:	number of channels
@@ -47,6 +48,7 @@  enum ad7887_channels {
  * @num_dual_channels:	number of channels in dual mode
  */
 struct ad7887_chip_info {
+	const char			*name;
 	u16				int_vref_mv;
 	const struct iio_chan_spec	*channels;
 	unsigned int			num_channels;
@@ -218,6 +220,7 @@  static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
 	 * More devices added in future
 	 */
 	[ID_AD7887] = {
+		.name = "ad7887",
 		.channels = ad7887_channels,
 		.num_channels = ARRAY_SIZE(ad7887_channels),
 		.dual_channels = ad7887_dual_channels,
@@ -239,12 +242,17 @@  static void ad7887_reg_disable(void *data)
 
 static int ad7887_probe(struct spi_device *spi)
 {
+	const struct ad7887_chip_info *info;
 	struct ad7887_state *st;
 	struct iio_dev *indio_dev;
 	bool dual_mode;
 	uint8_t mode;
 	int ret;
 
+	info = device_get_match_data(&spi->dev);
+	if (!info)
+		return -ENODEV;
+
 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 	if (indio_dev == NULL)
 		return -ENOMEM;
@@ -269,13 +277,12 @@  static int ad7887_probe(struct spi_device *spi)
 			return ret;
 	}
 
-	st->chip_info =
-		&ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+	st->chip_info = info;
 
 	spi_set_drvdata(spi, indio_dev);
 	st->spi = spi;
 
-	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->name = st->chip_info->name;
 	indio_dev->info = &ad7887_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
@@ -336,18 +343,18 @@  static int ad7887_probe(struct spi_device *spi)
 	return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
-static const struct spi_device_id ad7887_id[] = {
-	{"ad7887", ID_AD7887},
-	{}
+static const struct of_device_id ad7887_of_match[] = {
+	{ .compatible = "adi,ad7887", .data = &ad7887_chip_info_tbl[ID_AD7887] },
+	{ }
 };
-MODULE_DEVICE_TABLE(spi, ad7887_id);
+MODULE_DEVICE_TABLE(of, ad7887_of_match);
 
 static struct spi_driver ad7887_driver = {
 	.driver = {
 		.name	= "ad7887",
+		.of_match_table	= ad7887_of_match,
 	},
 	.probe		= ad7887_probe,
-	.id_table	= ad7887_id,
 };
 module_spi_driver(ad7887_driver);