[1/7] iio: adc: sun4i-gpadc: rework for support multiple thermal sensor
diff mbox series

Message ID 20190503072813.2719-2-tiny.windzz@gmail.com
State New
Headers show
Series
  • Add support for H6 thermal sensor
Related show

Commit Message

Frank Lee May 3, 2019, 7:28 a.m. UTC
For some SOCs, there are more than one thermal sensor, and there are
currently four sensors on the A80. So we need to do some work in order
to support multiple thermal sensors:

  1) add sensor_count in gpadc_data.
  2) introduce sun4i_sensor_tzd in sun4i_gpadc_iio, to support multiple
     thermal_zone_device and distinguish between different sensors.
  3) modify read temperature and initialization function.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
---
 drivers/iio/adc/sun4i-gpadc-iio.c | 61 +++++++++++++++++++++++--------
 1 file changed, 45 insertions(+), 16 deletions(-)

Comments

Jonathan Cameron May 5, 2019, 3:22 p.m. UTC | #1
On Fri,  3 May 2019 03:28:07 -0400
Yangtao Li <tiny.windzz@gmail.com> wrote:

> For some SOCs, there are more than one thermal sensor, and there are
> currently four sensors on the A80. So we need to do some work in order
> to support multiple thermal sensors:
> 
>   1) add sensor_count in gpadc_data.
>   2) introduce sun4i_sensor_tzd in sun4i_gpadc_iio, to support multiple
>      thermal_zone_device and distinguish between different sensors.
>   3) modify read temperature and initialization function.
This comment doesn't mention the devm change. If it had it would have
raised immediate alarm bells.

I'm also not keen on the web of pointers that this driver is steadily
evolving.  I can't immediately see how to reduce that complexity however.

Jonathan

> 
> Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
> ---
>  drivers/iio/adc/sun4i-gpadc-iio.c | 61 +++++++++++++++++++++++--------
>  1 file changed, 45 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/iio/adc/sun4i-gpadc-iio.c b/drivers/iio/adc/sun4i-gpadc-iio.c
> index 04d7147e0110..844fd52bd22f 100644
> --- a/drivers/iio/adc/sun4i-gpadc-iio.c
> +++ b/drivers/iio/adc/sun4i-gpadc-iio.c
> @@ -56,6 +56,7 @@ struct gpadc_data {
>  	unsigned int	tp_adc_select;
>  	unsigned int	(*adc_chan_select)(unsigned int chan);
>  	unsigned int	adc_chan_mask;
> +	unsigned int    sensor_count;
>  };
>  
>  static const struct gpadc_data sun4i_gpadc_data = {
> @@ -65,6 +66,7 @@ static const struct gpadc_data sun4i_gpadc_data = {
>  	.tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
>  	.adc_chan_select = &sun4i_gpadc_chan_select,
>  	.adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
> +	.sensor_count = 1,
>  };
>  
>  static const struct gpadc_data sun5i_gpadc_data = {
> @@ -74,6 +76,7 @@ static const struct gpadc_data sun5i_gpadc_data = {
>  	.tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
>  	.adc_chan_select = &sun4i_gpadc_chan_select,
>  	.adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
> +	.sensor_count = 1,
>  };
>  
>  static const struct gpadc_data sun6i_gpadc_data = {
> @@ -83,14 +86,24 @@ static const struct gpadc_data sun6i_gpadc_data = {
>  	.tp_adc_select = SUN6I_GPADC_CTRL1_TP_ADC_SELECT,
>  	.adc_chan_select = &sun6i_gpadc_chan_select,
>  	.adc_chan_mask = SUN6I_GPADC_CTRL1_ADC_CHAN_MASK,
> +	.sensor_count = 1,
>  };
>  
>  static const struct gpadc_data sun8i_a33_gpadc_data = {
>  	.temp_offset = -1662,
>  	.temp_scale = 162,
>  	.tp_mode_en = SUN8I_GPADC_CTRL1_CHOP_TEMP_EN,
> +	.sensor_count = 1,
>  };
>  
> +struct sun4i_sensor_tzd {
> +	struct sun4i_gpadc_iio          *info;
> +	struct thermal_zone_device      *tzd;
> +	unsigned int                    sensor_id;
> +};
> +
> +#define MAX_SENSOR_COUNT	4
> +
>  struct sun4i_gpadc_iio {
>  	struct iio_dev			*indio_dev;
>  	struct completion		completion;
> @@ -105,7 +118,7 @@ struct sun4i_gpadc_iio {
>  	bool				no_irq;
>  	/* prevents concurrent reads of temperature and ADC */
>  	struct mutex			mutex;
> -	struct thermal_zone_device	*tzd;
> +	struct sun4i_sensor_tzd         tzds[MAX_SENSOR_COUNT];
>  	struct device			*sensor_device;
>  };
>  
> @@ -270,7 +283,8 @@ static int sun4i_gpadc_adc_read(struct iio_dev *indio_dev, int channel,
>  	return sun4i_gpadc_read(indio_dev, channel, val, info->fifo_data_irq);
>  }
>  
> -static int sun4i_gpadc_temp_read(struct iio_dev *indio_dev, int *val)
> +static int sun4i_gpadc_temp_read(struct iio_dev *indio_dev, int *val,
> +				 unsigned int sensor)
>  {
>  	struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
>  
> @@ -324,7 +338,7 @@ static int sun4i_gpadc_read_raw(struct iio_dev *indio_dev,
>  			ret = sun4i_gpadc_adc_read(indio_dev, chan->channel,
>  						   val);
>  		else
> -			ret = sun4i_gpadc_temp_read(indio_dev, val);
> +			ret = sun4i_gpadc_temp_read(indio_dev, val, 0);
>  
>  		if (ret)
>  			return ret;
> @@ -417,10 +431,11 @@ static int sun4i_gpadc_runtime_resume(struct device *dev)
>  
>  static int sun4i_gpadc_get_temp(void *data, int *temp)
>  {
> -	struct sun4i_gpadc_iio *info = data;
> +	struct sun4i_sensor_tzd *tzd = data;
> +	struct sun4i_gpadc_iio *info = tzd->info;
>  	int val, scale, offset;
>  
> -	if (sun4i_gpadc_temp_read(info->indio_dev, &val))
> +	if (sun4i_gpadc_temp_read(info->indio_dev, &val, tzd->sensor_id))
>  		return -ETIMEDOUT;
>  
>  	sun4i_gpadc_temp_scale(info->indio_dev, &scale);
> @@ -609,6 +624,28 @@ static int sun4i_gpadc_probe_mfd(struct platform_device *pdev,
>  	return 0;
>  }
>  
> +static int sun4i_sensor_init(struct sun4i_gpadc_iio *info)
> +{
> +	int i = 0;
> +
> +	for (; i < info->data->sensor_count; i++) {
> +		info->tzds[i].info = info;
> +		info->tzds[i].sensor_id = i;
> +		info->tzds[i].tzd = devm_thermal_zone_of_sensor_register(
> +					info->sensor_device, i, &info->tzds[i],
> +					&sun4i_ts_tz_ops);

Using devm here has the result that the thermal_zones are remove 'after'
the end of the remove function for this driver.  That means you have
them still registered after several other commands are run in the remove
function.

Please ensure that the probe and remove orders are mirror images of each
other. Here it doesn't make a huge amount of actual difference but
it does make the code harder to reason about.

You 'could' propose a devm_ version of iio_map_array_register and
then use that to ensure the ordering is correctly maintained.

> +
> +		if (IS_ERR(info->tzds[i].tzd)) {
> +			dev_err(info->sensor_device,
> +				"could not register thermal sensor: %ld\n",
> +				PTR_ERR(info->tzds[i].tzd));
> +			return PTR_ERR(info->tzds[i].tzd);
> +		}
> +	}
> +
> +	return 0;
> +}
> +
>  static int sun4i_gpadc_probe(struct platform_device *pdev)
>  {
>  	struct sun4i_gpadc_iio *info;
> @@ -646,19 +683,13 @@ static int sun4i_gpadc_probe(struct platform_device *pdev)
>  	pm_runtime_enable(&pdev->dev);
>  
>  	if (IS_ENABLED(CONFIG_THERMAL_OF)) {
> -		info->tzd = thermal_zone_of_sensor_register(info->sensor_device,
> -							    0, info,
> -							    &sun4i_ts_tz_ops);
> +		ret = sun4i_sensor_init(info);
>  		/*
>  		 * Do not fail driver probing when failing to register in
>  		 * thermal because no thermal DT node is found.
>  		 */
> -		if (IS_ERR(info->tzd) && PTR_ERR(info->tzd) != -ENODEV) {
> -			dev_err(&pdev->dev,
> -				"could not register thermal sensor: %ld\n",
> -				PTR_ERR(info->tzd));
> -			return PTR_ERR(info->tzd);
> -		}
> +		if (ret && ret != -ENODEV)
> +			return ret;
>  	}
>  
>  	ret = devm_iio_device_register(&pdev->dev, indio_dev);
> @@ -690,8 +721,6 @@ static int sun4i_gpadc_remove(struct platform_device *pdev)
>  	if (!IS_ENABLED(CONFIG_THERMAL_OF))
>  		return 0;
>  
> -	thermal_zone_of_sensor_unregister(info->sensor_device, info->tzd);
> -
>  	if (!info->no_irq)
>  		iio_map_array_unregister(indio_dev);
>
Maxime Ripard May 6, 2019, 12:28 p.m. UTC | #2
Hi,

On Sun, May 05, 2019 at 04:22:15PM +0100, Jonathan Cameron wrote:
> On Fri,  3 May 2019 03:28:07 -0400
> Yangtao Li <tiny.windzz@gmail.com> wrote:
>
> > For some SOCs, there are more than one thermal sensor, and there are
> > currently four sensors on the A80. So we need to do some work in order
> > to support multiple thermal sensors:
> >
> >   1) add sensor_count in gpadc_data.
> >   2) introduce sun4i_sensor_tzd in sun4i_gpadc_iio, to support multiple
> >      thermal_zone_device and distinguish between different sensors.
> >   3) modify read temperature and initialization function.
>
> This comment doesn't mention the devm change. If it had it would have
> raised immediate alarm bells.
>
> I'm also not keen on the web of pointers that this driver is steadily
> evolving.  I can't immediately see how to reduce that complexity however.

So I might be responsible for that, and looking back, this has been a
mistake.

This driver was initally put together to support a controller found in
older (A10 up to A31) Allwinner SoCs. This controller had an ADC
driver that could be operated as a touchscreen controller, and was
providing a CPU temperature sensor and a general purpose ADC.

However, we already had a driver for that controller in drivers/input
to report the CPU temperature, and the one in IIO was introduced to
support the general purpose ADC (and the CPU temperature). The long
term goal was to add the touchscreen feature as well eventually so
that we could remove the one in drivers/input. That didn't happen.

At the same time, the Allwinner hardware slowly evolved to remove the
touchscreen and ADC features, and only keep the CPU temperature
readout. It then evolved further on to support multiple temperatures
(for different clusters, the GPU, and so on).

So, today, we're in a situation where I was pushing everything into
that IIO drivers since there was similiraties between all the
generations, but the fact that we have to support so many odd cases
(DT bindings compatibility, controllers with and without ADC, etc)
that it becomes a real mess.

And that mess isn't really used by anybody, since we want to have the
touchscreen.

There's only one SoC that is supported only by that driver, which is
the A33 that only had a CPU temperature readout, and is still pretty
similar to the latest SoC from Allwinner (that is supported by this
series).

I guess, for everyone's sanity and in order to not stall this further,
it would just be better to create an hwmon driver for the A33 (and
onwards, including the H6) for the SoC that just have the temperature
readout feature. And for the older SoC, we just keep the older driver
under input/. Once the A33 is supported, we'll remove the driver in
IIO (and the related bits in drivers/mfd).

Armbian already has a driver for that they never upstreamed iirc, so
it might be a good starting point, and we would add the support for
the H6. How does that sound?

Sorry for wasting everybody's time on this.

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
Icenowy Zheng May 6, 2019, 4:52 p.m. UTC | #3
在 2019-05-06一的 14:28 +0200,Maxime Ripard写道:
> Hi,
> 
> On Sun, May 05, 2019 at 04:22:15PM +0100, Jonathan Cameron wrote:
> > On Fri,  3 May 2019 03:28:07 -0400
> > Yangtao Li <tiny.windzz@gmail.com> wrote:
> > 
> > > For some SOCs, there are more than one thermal sensor, and there
> > > are
> > > currently four sensors on the A80. So we need to do some work in
> > > order
> > > to support multiple thermal sensors:
> > > 
> > >   1) add sensor_count in gpadc_data.
> > >   2) introduce sun4i_sensor_tzd in sun4i_gpadc_iio, to support
> > > multiple
> > >      thermal_zone_device and distinguish between different
> > > sensors.
> > >   3) modify read temperature and initialization function.
> > 
> > This comment doesn't mention the devm change. If it had it would
> > have
> > raised immediate alarm bells.
> > 
> > I'm also not keen on the web of pointers that this driver is
> > steadily
> > evolving.  I can't immediately see how to reduce that complexity
> > however.
> 
> So I might be responsible for that, and looking back, this has been a
> mistake.
> 
> This driver was initally put together to support a controller found
> in
> older (A10 up to A31) Allwinner SoCs. This controller had an ADC
> driver that could be operated as a touchscreen controller, and was
> providing a CPU temperature sensor and a general purpose ADC.
> 
> However, we already had a driver for that controller in drivers/input
> to report the CPU temperature, and the one in IIO was introduced to
> support the general purpose ADC (and the CPU temperature). The long
> term goal was to add the touchscreen feature as well eventually so
> that we could remove the one in drivers/input. That didn't happen.
> 
> At the same time, the Allwinner hardware slowly evolved to remove the
> touchscreen and ADC features, and only keep the CPU temperature
> readout. It then evolved further on to support multiple temperatures
> (for different clusters, the GPU, and so on).
> 
> So, today, we're in a situation where I was pushing everything into
> that IIO drivers since there was similiraties between all the
> generations, but the fact that we have to support so many odd cases
> (DT bindings compatibility, controllers with and without ADC, etc)
> that it becomes a real mess.
> 
> And that mess isn't really used by anybody, since we want to have the
> touchscreen.
> 
> There's only one SoC that is supported only by that driver, which is
> the A33 that only had a CPU temperature readout, and is still pretty
> similar to the latest SoC from Allwinner (that is supported by this
> series).
> 
> I guess, for everyone's sanity and in order to not stall this
> further,
> it would just be better to create an hwmon driver for the A33 (and
> onwards, including the H6) for the SoC that just have the temperature
> readout feature. And for the older SoC, we just keep the older driver
> under input/. Once the A33 is supported, we'll remove the driver in
> IIO (and the related bits in drivers/mfd).

I think a thermal driver is better.

Other SoCs' thermal sensor drivers are all thermal drivers.

> 
> Armbian already has a driver for that they never upstreamed iirc, so
> it might be a good starting point, and we would add the support for
> the H6. How does that sound?

I think the developer abandoned to upstream it because of the previous
problem ;-)

Maybe it can be taken and add A33&H6 support.

> 
> Sorry for wasting everybody's time on this.
> 
> Maxime
> 
> --
> Maxime Ripard, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Frank Lee May 6, 2019, 5:08 p.m. UTC | #4
On Tue, May 7, 2019 at 12:52 AM Icenowy Zheng <icenowy@aosc.io> wrote:
>
> 在 2019-05-06一的 14:28 +0200,Maxime Ripard写道:
> > Hi,
> >
> > On Sun, May 05, 2019 at 04:22:15PM +0100, Jonathan Cameron wrote:
> > > On Fri,  3 May 2019 03:28:07 -0400
> > > Yangtao Li <tiny.windzz@gmail.com> wrote:
> > >
> > > > For some SOCs, there are more than one thermal sensor, and there
> > > > are
> > > > currently four sensors on the A80. So we need to do some work in
> > > > order
> > > > to support multiple thermal sensors:
> > > >
> > > >   1) add sensor_count in gpadc_data.
> > > >   2) introduce sun4i_sensor_tzd in sun4i_gpadc_iio, to support
> > > > multiple
> > > >      thermal_zone_device and distinguish between different
> > > > sensors.
> > > >   3) modify read temperature and initialization function.
> > >
> > > This comment doesn't mention the devm change. If it had it would
> > > have
> > > raised immediate alarm bells.
> > >
> > > I'm also not keen on the web of pointers that this driver is
> > > steadily
> > > evolving.  I can't immediately see how to reduce that complexity
> > > however.
> >
> > So I might be responsible for that, and looking back, this has been a
> > mistake.
> >
> > This driver was initally put together to support a controller found
> > in
> > older (A10 up to A31) Allwinner SoCs. This controller had an ADC
> > driver that could be operated as a touchscreen controller, and was
> > providing a CPU temperature sensor and a general purpose ADC.
> >
> > However, we already had a driver for that controller in drivers/input
> > to report the CPU temperature, and the one in IIO was introduced to
> > support the general purpose ADC (and the CPU temperature). The long
> > term goal was to add the touchscreen feature as well eventually so
> > that we could remove the one in drivers/input. That didn't happen.
> >
> > At the same time, the Allwinner hardware slowly evolved to remove the
> > touchscreen and ADC features, and only keep the CPU temperature
> > readout. It then evolved further on to support multiple temperatures
> > (for different clusters, the GPU, and so on).
> >
> > So, today, we're in a situation where I was pushing everything into
> > that IIO drivers since there was similiraties between all the
> > generations, but the fact that we have to support so many odd cases
> > (DT bindings compatibility, controllers with and without ADC, etc)
> > that it becomes a real mess.
> >
> > And that mess isn't really used by anybody, since we want to have the
> > touchscreen.
> >
> > There's only one SoC that is supported only by that driver, which is
> > the A33 that only had a CPU temperature readout, and is still pretty
> > similar to the latest SoC from Allwinner (that is supported by this
> > series).
> >
> > I guess, for everyone's sanity and in order to not stall this
> > further,
> > it would just be better to create an hwmon driver for the A33 (and
> > onwards, including the H6) for the SoC that just have the temperature
> > readout feature. And for the older SoC, we just keep the older driver
> > under input/. Once the A33 is supported, we'll remove the driver in
> > IIO (and the related bits in drivers/mfd).

a hwmon driver or a thermal driver?

>
> I think a thermal driver is better.

This is what I hope to see a few months ago.

>
> Other SoCs' thermal sensor drivers are all thermal drivers.
>
> >
> > Armbian already has a driver for that they never upstreamed iirc, so
> > it might be a good starting point, and we would add the support for
> > the H6. How does that sound?
>
> I think the developer abandoned to upstream it because of the previous
> problem ;-)
>
> Maybe it can be taken and add A33&H6 support.

If OK, I am going to start some thermal driver work this weekend.  : )

Cheers,
Yangtao

>
> >
> > Sorry for wasting everybody's time on this.
> >
> > Maxime
> >
> > --
> > Maxime Ripard, Bootlin
> > Embedded Linux and Kernel engineering
> > https://bootlin.com
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
Ondřej Jirman May 6, 2019, 5:55 p.m. UTC | #5
Hi,

On Tue, May 07, 2019 at 01:08:39AM +0800, Frank Lee wrote:
> On Tue, May 7, 2019 at 12:52 AM Icenowy Zheng <icenowy@aosc.io> wrote:
> >
> > 在 2019-05-06一的 14:28 +0200,Maxime Ripard写道:
> > > Hi,
> > >
> > > On Sun, May 05, 2019 at 04:22:15PM +0100, Jonathan Cameron wrote:
> > > > On Fri,  3 May 2019 03:28:07 -0400
> > > > Yangtao Li <tiny.windzz@gmail.com> wrote:
> > > >
> > > > > For some SOCs, there are more than one thermal sensor, and there
> > > > > are
> > > > > currently four sensors on the A80. So we need to do some work in
> > > > > order
> > > > > to support multiple thermal sensors:
> > > > >
> > > > >   1) add sensor_count in gpadc_data.
> > > > >   2) introduce sun4i_sensor_tzd in sun4i_gpadc_iio, to support
> > > > > multiple
> > > > >      thermal_zone_device and distinguish between different
> > > > > sensors.
> > > > >   3) modify read temperature and initialization function.
> > > >
> > > > This comment doesn't mention the devm change. If it had it would
> > > > have
> > > > raised immediate alarm bells.
> > > >
> > > > I'm also not keen on the web of pointers that this driver is
> > > > steadily
> > > > evolving.  I can't immediately see how to reduce that complexity
> > > > however.
> > >
> > > So I might be responsible for that, and looking back, this has been a
> > > mistake.
> > >
> > > This driver was initally put together to support a controller found
> > > in
> > > older (A10 up to A31) Allwinner SoCs. This controller had an ADC
> > > driver that could be operated as a touchscreen controller, and was
> > > providing a CPU temperature sensor and a general purpose ADC.
> > >
> > > However, we already had a driver for that controller in drivers/input
> > > to report the CPU temperature, and the one in IIO was introduced to
> > > support the general purpose ADC (and the CPU temperature). The long
> > > term goal was to add the touchscreen feature as well eventually so
> > > that we could remove the one in drivers/input. That didn't happen.
> > >
> > > At the same time, the Allwinner hardware slowly evolved to remove the
> > > touchscreen and ADC features, and only keep the CPU temperature
> > > readout. It then evolved further on to support multiple temperatures
> > > (for different clusters, the GPU, and so on).
> > >
> > > So, today, we're in a situation where I was pushing everything into
> > > that IIO drivers since there was similiraties between all the
> > > generations, but the fact that we have to support so many odd cases
> > > (DT bindings compatibility, controllers with and without ADC, etc)
> > > that it becomes a real mess.
> > >
> > > And that mess isn't really used by anybody, since we want to have the
> > > touchscreen.
> > >
> > > There's only one SoC that is supported only by that driver, which is
> > > the A33 that only had a CPU temperature readout, and is still pretty
> > > similar to the latest SoC from Allwinner (that is supported by this
> > > series).
> > >
> > > I guess, for everyone's sanity and in order to not stall this
> > > further,
> > > it would just be better to create an hwmon driver for the A33 (and
> > > onwards, including the H6) for the SoC that just have the temperature
> > > readout feature. And for the older SoC, we just keep the older driver
> > > under input/. Once the A33 is supported, we'll remove the driver in
> > > IIO (and the related bits in drivers/mfd).
> 
> a hwmon driver or a thermal driver?
> 
> >
> > I think a thermal driver is better.
> 
> This is what I hope to see a few months ago.
> 
> >
> > Other SoCs' thermal sensor drivers are all thermal drivers.
> >
> > >
> > > Armbian already has a driver for that they never upstreamed iirc, so
> > > it might be a good starting point, and we would add the support for
> > > the H6. How does that sound?
> >
> > I think the developer abandoned to upstream it because of the previous
> > problem ;-)
> >
> > Maybe it can be taken and add A33&H6 support.
> 
> If OK, I am going to start some thermal driver work this weekend.  : )

There are plenty of thermal drivers flying around, with varying levels
of support for various SoCs:

- H3/H5: https://megous.com/git/linux/commit/?h=ths-5.1&id=b8e20c5da7a00b3a3fa1b274fc8d5bea95872b0a
- A83T: https://megous.com/git/linux/commit/?h=ths-5.1&id=796dff9a946fd475cc1e4bb948a723ea841c640c
- H6: https://megous.com/git/linux/commit/?h=opi3-5.1&id=aeab762c19b4aa228a295258c9d6b2e1f143bf86

For H3/H5 Icenowy also tried to upstream some variant of my THS driver, with
better SID/calibration data reading support.

I'd suggest starting with the H6 driver above (as that implements the
calibration data readout correctly), and make it so that it can support multiple
SoCs.

regards,
	o.

> Cheers,
> Yangtao
> 
> >
> > >
> > > Sorry for wasting everybody's time on this.
> > >
> > > Maxime
> > >
> > > --
> > > Maxime Ripard, Bootlin
> > > Embedded Linux and Kernel engineering
> > > https://bootlin.com
> > > _______________________________________________
> > > linux-arm-kernel mailing list
> > > linux-arm-kernel@lists.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> >
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Maxime Ripard May 7, 2019, 1:59 p.m. UTC | #6
On Mon, May 06, 2019 at 07:55:25PM +0200, Ondřej Jirman wrote:
> On Tue, May 07, 2019 at 01:08:39AM +0800, Frank Lee wrote:
> > On Tue, May 7, 2019 at 12:52 AM Icenowy Zheng <icenowy@aosc.io> wrote:
> > >
> > > 在 2019-05-06一的 14:28 +0200,Maxime Ripard写道:
> > > > Hi,
> > > >
> > > > On Sun, May 05, 2019 at 04:22:15PM +0100, Jonathan Cameron wrote:
> > > > > On Fri,  3 May 2019 03:28:07 -0400
> > > > > Yangtao Li <tiny.windzz@gmail.com> wrote:
> > > > >
> > > > > > For some SOCs, there are more than one thermal sensor, and there
> > > > > > are
> > > > > > currently four sensors on the A80. So we need to do some work in
> > > > > > order
> > > > > > to support multiple thermal sensors:
> > > > > >
> > > > > >   1) add sensor_count in gpadc_data.
> > > > > >   2) introduce sun4i_sensor_tzd in sun4i_gpadc_iio, to support
> > > > > > multiple
> > > > > >      thermal_zone_device and distinguish between different
> > > > > > sensors.
> > > > > >   3) modify read temperature and initialization function.
> > > > >
> > > > > This comment doesn't mention the devm change. If it had it would
> > > > > have
> > > > > raised immediate alarm bells.
> > > > >
> > > > > I'm also not keen on the web of pointers that this driver is
> > > > > steadily
> > > > > evolving.  I can't immediately see how to reduce that complexity
> > > > > however.
> > > >
> > > > So I might be responsible for that, and looking back, this has been a
> > > > mistake.
> > > >
> > > > This driver was initally put together to support a controller found
> > > > in
> > > > older (A10 up to A31) Allwinner SoCs. This controller had an ADC
> > > > driver that could be operated as a touchscreen controller, and was
> > > > providing a CPU temperature sensor and a general purpose ADC.
> > > >
> > > > However, we already had a driver for that controller in drivers/input
> > > > to report the CPU temperature, and the one in IIO was introduced to
> > > > support the general purpose ADC (and the CPU temperature). The long
> > > > term goal was to add the touchscreen feature as well eventually so
> > > > that we could remove the one in drivers/input. That didn't happen.
> > > >
> > > > At the same time, the Allwinner hardware slowly evolved to remove the
> > > > touchscreen and ADC features, and only keep the CPU temperature
> > > > readout. It then evolved further on to support multiple temperatures
> > > > (for different clusters, the GPU, and so on).
> > > >
> > > > So, today, we're in a situation where I was pushing everything into
> > > > that IIO drivers since there was similiraties between all the
> > > > generations, but the fact that we have to support so many odd cases
> > > > (DT bindings compatibility, controllers with and without ADC, etc)
> > > > that it becomes a real mess.
> > > >
> > > > And that mess isn't really used by anybody, since we want to have the
> > > > touchscreen.
> > > >
> > > > There's only one SoC that is supported only by that driver, which is
> > > > the A33 that only had a CPU temperature readout, and is still pretty
> > > > similar to the latest SoC from Allwinner (that is supported by this
> > > > series).
> > > >
> > > > I guess, for everyone's sanity and in order to not stall this
> > > > further,
> > > > it would just be better to create an hwmon driver for the A33 (and
> > > > onwards, including the H6) for the SoC that just have the temperature
> > > > readout feature. And for the older SoC, we just keep the older driver
> > > > under input/. Once the A33 is supported, we'll remove the driver in
> > > > IIO (and the related bits in drivers/mfd).
> >
> > a hwmon driver or a thermal driver?
> >
> > >
> > > I think a thermal driver is better.
> >
> > This is what I hope to see a few months ago.
> >
> > >
> > > Other SoCs' thermal sensor drivers are all thermal drivers.
> > >
> > > >
> > > > Armbian already has a driver for that they never upstreamed iirc, so
> > > > it might be a good starting point, and we would add the support for
> > > > the H6. How does that sound?
> > >
> > > I think the developer abandoned to upstream it because of the previous
> > > problem ;-)
> > >
> > > Maybe it can be taken and add A33&H6 support.
> >
> > If OK, I am going to start some thermal driver work this weekend.  : )
>
> There are plenty of thermal drivers flying around, with varying levels
> of support for various SoCs:
>
> - H3/H5: https://megous.com/git/linux/commit/?h=ths-5.1&id=b8e20c5da7a00b3a3fa1b274fc8d5bea95872b0a
> - A83T: https://megous.com/git/linux/commit/?h=ths-5.1&id=796dff9a946fd475cc1e4bb948a723ea841c640c
> - H6: https://megous.com/git/linux/commit/?h=opi3-5.1&id=aeab762c19b4aa228a295258c9d6b2e1f143bf86
>
> For H3/H5 Icenowy also tried to upstream some variant of my THS driver, with
> better SID/calibration data reading support.
>
> I'd suggest starting with the H6 driver above (as that implements the
> calibration data readout correctly), and make it so that it can support multiple
> SoCs.

Yeah, that seems like a good plan

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Patch
diff mbox series

diff --git a/drivers/iio/adc/sun4i-gpadc-iio.c b/drivers/iio/adc/sun4i-gpadc-iio.c
index 04d7147e0110..844fd52bd22f 100644
--- a/drivers/iio/adc/sun4i-gpadc-iio.c
+++ b/drivers/iio/adc/sun4i-gpadc-iio.c
@@ -56,6 +56,7 @@  struct gpadc_data {
 	unsigned int	tp_adc_select;
 	unsigned int	(*adc_chan_select)(unsigned int chan);
 	unsigned int	adc_chan_mask;
+	unsigned int    sensor_count;
 };
 
 static const struct gpadc_data sun4i_gpadc_data = {
@@ -65,6 +66,7 @@  static const struct gpadc_data sun4i_gpadc_data = {
 	.tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
 	.adc_chan_select = &sun4i_gpadc_chan_select,
 	.adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
+	.sensor_count = 1,
 };
 
 static const struct gpadc_data sun5i_gpadc_data = {
@@ -74,6 +76,7 @@  static const struct gpadc_data sun5i_gpadc_data = {
 	.tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
 	.adc_chan_select = &sun4i_gpadc_chan_select,
 	.adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
+	.sensor_count = 1,
 };
 
 static const struct gpadc_data sun6i_gpadc_data = {
@@ -83,14 +86,24 @@  static const struct gpadc_data sun6i_gpadc_data = {
 	.tp_adc_select = SUN6I_GPADC_CTRL1_TP_ADC_SELECT,
 	.adc_chan_select = &sun6i_gpadc_chan_select,
 	.adc_chan_mask = SUN6I_GPADC_CTRL1_ADC_CHAN_MASK,
+	.sensor_count = 1,
 };
 
 static const struct gpadc_data sun8i_a33_gpadc_data = {
 	.temp_offset = -1662,
 	.temp_scale = 162,
 	.tp_mode_en = SUN8I_GPADC_CTRL1_CHOP_TEMP_EN,
+	.sensor_count = 1,
 };
 
+struct sun4i_sensor_tzd {
+	struct sun4i_gpadc_iio          *info;
+	struct thermal_zone_device      *tzd;
+	unsigned int                    sensor_id;
+};
+
+#define MAX_SENSOR_COUNT	4
+
 struct sun4i_gpadc_iio {
 	struct iio_dev			*indio_dev;
 	struct completion		completion;
@@ -105,7 +118,7 @@  struct sun4i_gpadc_iio {
 	bool				no_irq;
 	/* prevents concurrent reads of temperature and ADC */
 	struct mutex			mutex;
-	struct thermal_zone_device	*tzd;
+	struct sun4i_sensor_tzd         tzds[MAX_SENSOR_COUNT];
 	struct device			*sensor_device;
 };
 
@@ -270,7 +283,8 @@  static int sun4i_gpadc_adc_read(struct iio_dev *indio_dev, int channel,
 	return sun4i_gpadc_read(indio_dev, channel, val, info->fifo_data_irq);
 }
 
-static int sun4i_gpadc_temp_read(struct iio_dev *indio_dev, int *val)
+static int sun4i_gpadc_temp_read(struct iio_dev *indio_dev, int *val,
+				 unsigned int sensor)
 {
 	struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
 
@@ -324,7 +338,7 @@  static int sun4i_gpadc_read_raw(struct iio_dev *indio_dev,
 			ret = sun4i_gpadc_adc_read(indio_dev, chan->channel,
 						   val);
 		else
-			ret = sun4i_gpadc_temp_read(indio_dev, val);
+			ret = sun4i_gpadc_temp_read(indio_dev, val, 0);
 
 		if (ret)
 			return ret;
@@ -417,10 +431,11 @@  static int sun4i_gpadc_runtime_resume(struct device *dev)
 
 static int sun4i_gpadc_get_temp(void *data, int *temp)
 {
-	struct sun4i_gpadc_iio *info = data;
+	struct sun4i_sensor_tzd *tzd = data;
+	struct sun4i_gpadc_iio *info = tzd->info;
 	int val, scale, offset;
 
-	if (sun4i_gpadc_temp_read(info->indio_dev, &val))
+	if (sun4i_gpadc_temp_read(info->indio_dev, &val, tzd->sensor_id))
 		return -ETIMEDOUT;
 
 	sun4i_gpadc_temp_scale(info->indio_dev, &scale);
@@ -609,6 +624,28 @@  static int sun4i_gpadc_probe_mfd(struct platform_device *pdev,
 	return 0;
 }
 
+static int sun4i_sensor_init(struct sun4i_gpadc_iio *info)
+{
+	int i = 0;
+
+	for (; i < info->data->sensor_count; i++) {
+		info->tzds[i].info = info;
+		info->tzds[i].sensor_id = i;
+		info->tzds[i].tzd = devm_thermal_zone_of_sensor_register(
+					info->sensor_device, i, &info->tzds[i],
+					&sun4i_ts_tz_ops);
+
+		if (IS_ERR(info->tzds[i].tzd)) {
+			dev_err(info->sensor_device,
+				"could not register thermal sensor: %ld\n",
+				PTR_ERR(info->tzds[i].tzd));
+			return PTR_ERR(info->tzds[i].tzd);
+		}
+	}
+
+	return 0;
+}
+
 static int sun4i_gpadc_probe(struct platform_device *pdev)
 {
 	struct sun4i_gpadc_iio *info;
@@ -646,19 +683,13 @@  static int sun4i_gpadc_probe(struct platform_device *pdev)
 	pm_runtime_enable(&pdev->dev);
 
 	if (IS_ENABLED(CONFIG_THERMAL_OF)) {
-		info->tzd = thermal_zone_of_sensor_register(info->sensor_device,
-							    0, info,
-							    &sun4i_ts_tz_ops);
+		ret = sun4i_sensor_init(info);
 		/*
 		 * Do not fail driver probing when failing to register in
 		 * thermal because no thermal DT node is found.
 		 */
-		if (IS_ERR(info->tzd) && PTR_ERR(info->tzd) != -ENODEV) {
-			dev_err(&pdev->dev,
-				"could not register thermal sensor: %ld\n",
-				PTR_ERR(info->tzd));
-			return PTR_ERR(info->tzd);
-		}
+		if (ret && ret != -ENODEV)
+			return ret;
 	}
 
 	ret = devm_iio_device_register(&pdev->dev, indio_dev);
@@ -690,8 +721,6 @@  static int sun4i_gpadc_remove(struct platform_device *pdev)
 	if (!IS_ENABLED(CONFIG_THERMAL_OF))
 		return 0;
 
-	thermal_zone_of_sensor_unregister(info->sensor_device, info->tzd);
-
 	if (!info->no_irq)
 		iio_map_array_unregister(indio_dev);