[PATCH v2] iio: dac: dac5571: Fix chip id detection for OF devices

[PATCH v2] iio: dac: dac5571: Fix chip id detection for OF devices

[Laurent Pinchart]

From: Jose Cazarin <joseespiriki@gmail.com>

When matching an OF device, the match mechanism tries all components of
the compatible property. This can result with a device matched with a
compatible string that isn't the first in the compatible list. For
instance, with a compatible property set to

    compatible = "ti,dac081c081", "ti,dac5571";

the driver will match the second compatible string, as the first one
isn't listed in the of_device_id table. The device will however be named
"dac081c081" by the I2C core.

This causes an issue when identifying the chip. The probe function
receives a i2c_device_id that comes from the module's I2C device ID
table. There is no entry in that table for "dac081c081", which results
in a NULL pointer passed to the probe function.

To fix this, add chip_id information in the data field of the OF device
ID table, and retrieve it with of_device_get_match_data() for OF
devices.

Signed-off-by: Jose Cazarin <joseespiriki@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v1:

- Use device_get_match_data()
---
 drivers/iio/dac/ti-dac5571.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/dac/ti-dac5571.c b/drivers/iio/dac/ti-dac5571.c
index 4a3b8d875518..4f50e31dffb0 100644
--- a/drivers/iio/dac/ti-dac5571.c
+++ b/drivers/iio/dac/ti-dac5571.c
@@ -19,6 +19,7 @@
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
+#include <linux/property.h>
 #include <linux/regulator/consumer.h>
 
 enum chip_id {
@@ -311,6 +312,7 @@ static int dac5571_probe(struct i2c_client *client,
 	const struct dac5571_spec *spec;
 	struct dac5571_data *data;
 	struct iio_dev *indio_dev;
+	enum chip_id chip_id;
 	int ret, i;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
@@ -326,7 +328,13 @@ static int dac5571_probe(struct i2c_client *client,
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = dac5571_channels;
 
-	spec = &dac5571_spec[id->driver_data];
+	if (dev->of_node)
+		chip_id = (uintptr_t)device_get_match_data(dev);
+	else
+		chip_id = id->driver_data;
+
+	spec = &dac5571_spec[chip_id];
+
 	indio_dev->num_channels = spec->num_channels;
 	data->spec = spec;
 
@@ -385,15 +393,15 @@ static int dac5571_remove(struct i2c_client *i2c)
 }
 
 static const struct of_device_id dac5571_of_id[] = {
-	{.compatible = "ti,dac5571"},
-	{.compatible = "ti,dac6571"},
-	{.compatible = "ti,dac7571"},
-	{.compatible = "ti,dac5574"},
-	{.compatible = "ti,dac6574"},
-	{.compatible = "ti,dac7574"},
-	{.compatible = "ti,dac5573"},
-	{.compatible = "ti,dac6573"},
-	{.compatible = "ti,dac7573"},
+	{.compatible = "ti,dac5571", .data = (void *)single_8bit},
+	{.compatible = "ti,dac6571", .data = (void *)single_10bit},
+	{.compatible = "ti,dac7571", .data = (void *)single_12bit},
+	{.compatible = "ti,dac5574", .data = (void *)quad_8bit},
+	{.compatible = "ti,dac6574", .data = (void *)quad_10bit},
+	{.compatible = "ti,dac7574", .data = (void *)quad_12bit},
+	{.compatible = "ti,dac5573", .data = (void *)quad_8bit},
+	{.compatible = "ti,dac6573", .data = (void *)quad_10bit},
+	{.compatible = "ti,dac7573", .data = (void *)quad_12bit},
 	{}
 };
 MODULE_DEVICE_TABLE(of, dac5571_of_id);
-- 
Regards,

Laurent Pinchart

Re: [PATCH v2] iio: dac: dac5571: Fix chip id detection for OF devices

[Jonathan Cameron]

On Fri, 25 Mar 2022 01:43:40 +0200
Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote:

> From: Jose Cazarin <joseespiriki@gmail.com>
> 
> When matching an OF device, the match mechanism tries all components of
> the compatible property. This can result with a device matched with a
> compatible string that isn't the first in the compatible list. For
> instance, with a compatible property set to
> 
>     compatible = "ti,dac081c081", "ti,dac5571";
> 
> the driver will match the second compatible string, as the first one
> isn't listed in the of_device_id table. The device will however be named
> "dac081c081" by the I2C core.
> 
> This causes an issue when identifying the chip. The probe function
> receives a i2c_device_id that comes from the module's I2C device ID
> table. There is no entry in that table for "dac081c081", which results
> in a NULL pointer passed to the probe function.
> 
> To fix this, add chip_id information in the data field of the OF device
> ID table, and retrieve it with of_device_get_match_data() for OF
> devices.

You forgot to update the patch description for the change to device_get_match_data()

One other thing inline.

Jonathan

> 
> Signed-off-by: Jose Cazarin <joseespiriki@gmail.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
> Changes since v1:
> 
> - Use device_get_match_data()
> ---
>  drivers/iio/dac/ti-dac5571.c | 28 ++++++++++++++++++----------
>  1 file changed, 18 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/iio/dac/ti-dac5571.c b/drivers/iio/dac/ti-dac5571.c
> index 4a3b8d875518..4f50e31dffb0 100644
> --- a/drivers/iio/dac/ti-dac5571.c
> +++ b/drivers/iio/dac/ti-dac5571.c
> @@ -19,6 +19,7 @@
>  #include <linux/i2c.h>
>  #include <linux/module.h>
>  #include <linux/mod_devicetable.h>
> +#include <linux/property.h>
>  #include <linux/regulator/consumer.h>
>  
>  enum chip_id {
> @@ -311,6 +312,7 @@ static int dac5571_probe(struct i2c_client *client,
>  	const struct dac5571_spec *spec;
>  	struct dac5571_data *data;
>  	struct iio_dev *indio_dev;
> +	enum chip_id chip_id;
>  	int ret, i;
>  
>  	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> @@ -326,7 +328,13 @@ static int dac5571_probe(struct i2c_client *client,
>  	indio_dev->modes = INDIO_DIRECT_MODE;
>  	indio_dev->channels = dac5571_channels;
>  
> -	spec = &dac5571_spec[id->driver_data];
> +	if (dev->of_node)

	if (dev_fwnode(dev))

> +		chip_id = (uintptr_t)device_get_match_data(dev);
> +	else
> +		chip_id = id->driver_data;
> +
> +	spec = &dac5571_spec[chip_id];
> +
>  	indio_dev->num_channels = spec->num_channels;
>  	data->spec = spec;
>  
> @@ -385,15 +393,15 @@ static int dac5571_remove(struct i2c_client *i2c)
>  }
>  
>  static const struct of_device_id dac5571_of_id[] = {
> -	{.compatible = "ti,dac5571"},
> -	{.compatible = "ti,dac6571"},
> -	{.compatible = "ti,dac7571"},
> -	{.compatible = "ti,dac5574"},
> -	{.compatible = "ti,dac6574"},
> -	{.compatible = "ti,dac7574"},
> -	{.compatible = "ti,dac5573"},
> -	{.compatible = "ti,dac6573"},
> -	{.compatible = "ti,dac7573"},
> +	{.compatible = "ti,dac5571", .data = (void *)single_8bit},
> +	{.compatible = "ti,dac6571", .data = (void *)single_10bit},
> +	{.compatible = "ti,dac7571", .data = (void *)single_12bit},
> +	{.compatible = "ti,dac5574", .data = (void *)quad_8bit},
> +	{.compatible = "ti,dac6574", .data = (void *)quad_10bit},
> +	{.compatible = "ti,dac7574", .data = (void *)quad_12bit},
> +	{.compatible = "ti,dac5573", .data = (void *)quad_8bit},
> +	{.compatible = "ti,dac6573", .data = (void *)quad_10bit},
> +	{.compatible = "ti,dac7573", .data = (void *)quad_12bit},
>  	{}
>  };
>  MODULE_DEVICE_TABLE(of, dac5571_of_id);

Re: [PATCH v2] iio: dac: dac5571: Fix chip id detection for OF devices

[Laurent Pinchart]

Hi Jonathan,

On Sun, Mar 27, 2022 at 03:34:38PM +0100, Jonathan Cameron wrote:
> On Fri, 25 Mar 2022 01:43:40 +0200 Laurent Pinchart wrote:
> 
> > From: Jose Cazarin <joseespiriki@gmail.com>
> > 
> > When matching an OF device, the match mechanism tries all components of
> > the compatible property. This can result with a device matched with a
> > compatible string that isn't the first in the compatible list. For
> > instance, with a compatible property set to
> > 
> >     compatible = "ti,dac081c081", "ti,dac5571";
> > 
> > the driver will match the second compatible string, as the first one
> > isn't listed in the of_device_id table. The device will however be named
> > "dac081c081" by the I2C core.
> > 
> > This causes an issue when identifying the chip. The probe function
> > receives a i2c_device_id that comes from the module's I2C device ID
> > table. There is no entry in that table for "dac081c081", which results
> > in a NULL pointer passed to the probe function.
> > 
> > To fix this, add chip_id information in the data field of the OF device
> > ID table, and retrieve it with of_device_get_match_data() for OF
> > devices.
> 
> You forgot to update the patch description for the change to device_get_match_data()
> 
> One other thing inline.

Thank you for the comments. I agree with both. Would you like me to send
a v3, or is this something you'd be happy fixing when applying the patch
to your tree ?

> > Signed-off-by: Jose Cazarin <joseespiriki@gmail.com>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> > Changes since v1:
> > 
> > - Use device_get_match_data()
> > ---
> >  drivers/iio/dac/ti-dac5571.c | 28 ++++++++++++++++++----------
> >  1 file changed, 18 insertions(+), 10 deletions(-)
> > 
> > diff --git a/drivers/iio/dac/ti-dac5571.c b/drivers/iio/dac/ti-dac5571.c
> > index 4a3b8d875518..4f50e31dffb0 100644
> > --- a/drivers/iio/dac/ti-dac5571.c
> > +++ b/drivers/iio/dac/ti-dac5571.c
> > @@ -19,6 +19,7 @@
> >  #include <linux/i2c.h>
> >  #include <linux/module.h>
> >  #include <linux/mod_devicetable.h>
> > +#include <linux/property.h>
> >  #include <linux/regulator/consumer.h>
> >  
> >  enum chip_id {
> > @@ -311,6 +312,7 @@ static int dac5571_probe(struct i2c_client *client,
> >  	const struct dac5571_spec *spec;
> >  	struct dac5571_data *data;
> >  	struct iio_dev *indio_dev;
> > +	enum chip_id chip_id;
> >  	int ret, i;
> >  
> >  	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> > @@ -326,7 +328,13 @@ static int dac5571_probe(struct i2c_client *client,
> >  	indio_dev->modes = INDIO_DIRECT_MODE;
> >  	indio_dev->channels = dac5571_channels;
> >  
> > -	spec = &dac5571_spec[id->driver_data];
> > +	if (dev->of_node)
> 
> 	if (dev_fwnode(dev))
> 
> > +		chip_id = (uintptr_t)device_get_match_data(dev);
> > +	else
> > +		chip_id = id->driver_data;
> > +
> > +	spec = &dac5571_spec[chip_id];
> > +
> >  	indio_dev->num_channels = spec->num_channels;
> >  	data->spec = spec;
> >  
> > @@ -385,15 +393,15 @@ static int dac5571_remove(struct i2c_client *i2c)
> >  }
> >  
> >  static const struct of_device_id dac5571_of_id[] = {
> > -	{.compatible = "ti,dac5571"},
> > -	{.compatible = "ti,dac6571"},
> > -	{.compatible = "ti,dac7571"},
> > -	{.compatible = "ti,dac5574"},
> > -	{.compatible = "ti,dac6574"},
> > -	{.compatible = "ti,dac7574"},
> > -	{.compatible = "ti,dac5573"},
> > -	{.compatible = "ti,dac6573"},
> > -	{.compatible = "ti,dac7573"},
> > +	{.compatible = "ti,dac5571", .data = (void *)single_8bit},
> > +	{.compatible = "ti,dac6571", .data = (void *)single_10bit},
> > +	{.compatible = "ti,dac7571", .data = (void *)single_12bit},
> > +	{.compatible = "ti,dac5574", .data = (void *)quad_8bit},
> > +	{.compatible = "ti,dac6574", .data = (void *)quad_10bit},
> > +	{.compatible = "ti,dac7574", .data = (void *)quad_12bit},
> > +	{.compatible = "ti,dac5573", .data = (void *)quad_8bit},
> > +	{.compatible = "ti,dac6573", .data = (void *)quad_10bit},
> > +	{.compatible = "ti,dac7573", .data = (void *)quad_12bit},
> >  	{}
> >  };
> >  MODULE_DEVICE_TABLE(of, dac5571_of_id);
> 

-- 
Regards,

Laurent Pinchart

Re: [PATCH v2] iio: dac: dac5571: Fix chip id detection for OF devices

[Jonathan Cameron]

On Sun, 27 Mar 2022 17:37:27 +0300
Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote:

> Hi Jonathan,
> 
> On Sun, Mar 27, 2022 at 03:34:38PM +0100, Jonathan Cameron wrote:
> > On Fri, 25 Mar 2022 01:43:40 +0200 Laurent Pinchart wrote:
> >   
> > > From: Jose Cazarin <joseespiriki@gmail.com>
> > > 
> > > When matching an OF device, the match mechanism tries all components of
> > > the compatible property. This can result with a device matched with a
> > > compatible string that isn't the first in the compatible list. For
> > > instance, with a compatible property set to
> > > 
> > >     compatible = "ti,dac081c081", "ti,dac5571";
> > > 
> > > the driver will match the second compatible string, as the first one
> > > isn't listed in the of_device_id table. The device will however be named
> > > "dac081c081" by the I2C core.
> > > 
> > > This causes an issue when identifying the chip. The probe function
> > > receives a i2c_device_id that comes from the module's I2C device ID
> > > table. There is no entry in that table for "dac081c081", which results
> > > in a NULL pointer passed to the probe function.
> > > 
> > > To fix this, add chip_id information in the data field of the OF device
> > > ID table, and retrieve it with of_device_get_match_data() for OF
> > > devices.  
> > 
> > You forgot to update the patch description for the change to device_get_match_data()
> > 
> > One other thing inline.  
> 
> Thank you for the comments. I agree with both. Would you like me to send
> a v3, or is this something you'd be happy fixing when applying the patch
> to your tree ?

I've applied it how with those changes.  However, it's on my fixes-togreg branch
and I don't plan to push that out until after rc1 when I can rebase it on something
'stable'.

Thanks,

Jonathan

> 
> > > Signed-off-by: Jose Cazarin <joseespiriki@gmail.com>
> > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > ---
> > > Changes since v1:
> > > 
> > > - Use device_get_match_data()
> > > ---
> > >  drivers/iio/dac/ti-dac5571.c | 28 ++++++++++++++++++----------
> > >  1 file changed, 18 insertions(+), 10 deletions(-)
> > > 
> > > diff --git a/drivers/iio/dac/ti-dac5571.c b/drivers/iio/dac/ti-dac5571.c
> > > index 4a3b8d875518..4f50e31dffb0 100644
> > > --- a/drivers/iio/dac/ti-dac5571.c
> > > +++ b/drivers/iio/dac/ti-dac5571.c
> > > @@ -19,6 +19,7 @@
> > >  #include <linux/i2c.h>
> > >  #include <linux/module.h>
> > >  #include <linux/mod_devicetable.h>
> > > +#include <linux/property.h>
> > >  #include <linux/regulator/consumer.h>
> > >  
> > >  enum chip_id {
> > > @@ -311,6 +312,7 @@ static int dac5571_probe(struct i2c_client *client,
> > >  	const struct dac5571_spec *spec;
> > >  	struct dac5571_data *data;
> > >  	struct iio_dev *indio_dev;
> > > +	enum chip_id chip_id;
> > >  	int ret, i;
> > >  
> > >  	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> > > @@ -326,7 +328,13 @@ static int dac5571_probe(struct i2c_client *client,
> > >  	indio_dev->modes = INDIO_DIRECT_MODE;
> > >  	indio_dev->channels = dac5571_channels;
> > >  
> > > -	spec = &dac5571_spec[id->driver_data];
> > > +	if (dev->of_node)  
> > 
> > 	if (dev_fwnode(dev))
> >   
> > > +		chip_id = (uintptr_t)device_get_match_data(dev);
> > > +	else
> > > +		chip_id = id->driver_data;
> > > +
> > > +	spec = &dac5571_spec[chip_id];
> > > +
> > >  	indio_dev->num_channels = spec->num_channels;
> > >  	data->spec = spec;
> > >  
> > > @@ -385,15 +393,15 @@ static int dac5571_remove(struct i2c_client *i2c)
> > >  }
> > >  
> > >  static const struct of_device_id dac5571_of_id[] = {
> > > -	{.compatible = "ti,dac5571"},
> > > -	{.compatible = "ti,dac6571"},
> > > -	{.compatible = "ti,dac7571"},
> > > -	{.compatible = "ti,dac5574"},
> > > -	{.compatible = "ti,dac6574"},
> > > -	{.compatible = "ti,dac7574"},
> > > -	{.compatible = "ti,dac5573"},
> > > -	{.compatible = "ti,dac6573"},
> > > -	{.compatible = "ti,dac7573"},
> > > +	{.compatible = "ti,dac5571", .data = (void *)single_8bit},
> > > +	{.compatible = "ti,dac6571", .data = (void *)single_10bit},
> > > +	{.compatible = "ti,dac7571", .data = (void *)single_12bit},
> > > +	{.compatible = "ti,dac5574", .data = (void *)quad_8bit},
> > > +	{.compatible = "ti,dac6574", .data = (void *)quad_10bit},
> > > +	{.compatible = "ti,dac7574", .data = (void *)quad_12bit},
> > > +	{.compatible = "ti,dac5573", .data = (void *)quad_8bit},
> > > +	{.compatible = "ti,dac6573", .data = (void *)quad_10bit},
> > > +	{.compatible = "ti,dac7573", .data = (void *)quad_12bit},
> > >  	{}
> > >  };
> > >  MODULE_DEVICE_TABLE(of, dac5571_of_id);  
> >   
> 

Re: [PATCH v2] iio: dac: dac5571: Fix chip id detection for OF devices

[Jonathan Cameron]

On Sun, 27 Mar 2022 16:59:01 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> On Sun, 27 Mar 2022 17:37:27 +0300
> Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote:
> 
> > Hi Jonathan,
> > 
> > On Sun, Mar 27, 2022 at 03:34:38PM +0100, Jonathan Cameron wrote:  
> > > On Fri, 25 Mar 2022 01:43:40 +0200 Laurent Pinchart wrote:
> > >     
> > > > From: Jose Cazarin <joseespiriki@gmail.com>
> > > > 
> > > > When matching an OF device, the match mechanism tries all components of
> > > > the compatible property. This can result with a device matched with a
> > > > compatible string that isn't the first in the compatible list. For
> > > > instance, with a compatible property set to
> > > > 
> > > >     compatible = "ti,dac081c081", "ti,dac5571";
> > > > 
> > > > the driver will match the second compatible string, as the first one
> > > > isn't listed in the of_device_id table. The device will however be named
> > > > "dac081c081" by the I2C core.
> > > > 
> > > > This causes an issue when identifying the chip. The probe function
> > > > receives a i2c_device_id that comes from the module's I2C device ID
> > > > table. There is no entry in that table for "dac081c081", which results
> > > > in a NULL pointer passed to the probe function.
> > > > 
> > > > To fix this, add chip_id information in the data field of the OF device
> > > > ID table, and retrieve it with of_device_get_match_data() for OF
> > > > devices.    
> > > 
> > > You forgot to update the patch description for the change to device_get_match_data()
> > > 
> > > One other thing inline.    
> > 
> > Thank you for the comments. I agree with both. Would you like me to send
> > a v3, or is this something you'd be happy fixing when applying the patch
> > to your tree ?  
> 
> I've applied it how with those changes.  However, it's on my fixes-togreg branch
now. 

I can't type on Sundays :)

Jonathan

> and I don't plan to push that out until after rc1 when I can rebase it on something
> 'stable'.
> 
> Thanks,
> 
> Jonathan
> 
> >   
> > > > Signed-off-by: Jose Cazarin <joseespiriki@gmail.com>
> > > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > > ---
> > > > Changes since v1:
> > > > 
> > > > - Use device_get_match_data()
> > > > ---
> > > >  drivers/iio/dac/ti-dac5571.c | 28 ++++++++++++++++++----------
> > > >  1 file changed, 18 insertions(+), 10 deletions(-)
> > > > 
> > > > diff --git a/drivers/iio/dac/ti-dac5571.c b/drivers/iio/dac/ti-dac5571.c
> > > > index 4a3b8d875518..4f50e31dffb0 100644
> > > > --- a/drivers/iio/dac/ti-dac5571.c
> > > > +++ b/drivers/iio/dac/ti-dac5571.c
> > > > @@ -19,6 +19,7 @@
> > > >  #include <linux/i2c.h>
> > > >  #include <linux/module.h>
> > > >  #include <linux/mod_devicetable.h>
> > > > +#include <linux/property.h>
> > > >  #include <linux/regulator/consumer.h>
> > > >  
> > > >  enum chip_id {
> > > > @@ -311,6 +312,7 @@ static int dac5571_probe(struct i2c_client *client,
> > > >  	const struct dac5571_spec *spec;
> > > >  	struct dac5571_data *data;
> > > >  	struct iio_dev *indio_dev;
> > > > +	enum chip_id chip_id;
> > > >  	int ret, i;
> > > >  
> > > >  	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> > > > @@ -326,7 +328,13 @@ static int dac5571_probe(struct i2c_client *client,
> > > >  	indio_dev->modes = INDIO_DIRECT_MODE;
> > > >  	indio_dev->channels = dac5571_channels;
> > > >  
> > > > -	spec = &dac5571_spec[id->driver_data];
> > > > +	if (dev->of_node)    
> > > 
> > > 	if (dev_fwnode(dev))
> > >     
> > > > +		chip_id = (uintptr_t)device_get_match_data(dev);
> > > > +	else
> > > > +		chip_id = id->driver_data;
> > > > +
> > > > +	spec = &dac5571_spec[chip_id];
> > > > +
> > > >  	indio_dev->num_channels = spec->num_channels;
> > > >  	data->spec = spec;
> > > >  
> > > > @@ -385,15 +393,15 @@ static int dac5571_remove(struct i2c_client *i2c)
> > > >  }
> > > >  
> > > >  static const struct of_device_id dac5571_of_id[] = {
> > > > -	{.compatible = "ti,dac5571"},
> > > > -	{.compatible = "ti,dac6571"},
> > > > -	{.compatible = "ti,dac7571"},
> > > > -	{.compatible = "ti,dac5574"},
> > > > -	{.compatible = "ti,dac6574"},
> > > > -	{.compatible = "ti,dac7574"},
> > > > -	{.compatible = "ti,dac5573"},
> > > > -	{.compatible = "ti,dac6573"},
> > > > -	{.compatible = "ti,dac7573"},
> > > > +	{.compatible = "ti,dac5571", .data = (void *)single_8bit},
> > > > +	{.compatible = "ti,dac6571", .data = (void *)single_10bit},
> > > > +	{.compatible = "ti,dac7571", .data = (void *)single_12bit},
> > > > +	{.compatible = "ti,dac5574", .data = (void *)quad_8bit},
> > > > +	{.compatible = "ti,dac6574", .data = (void *)quad_10bit},
> > > > +	{.compatible = "ti,dac7574", .data = (void *)quad_12bit},
> > > > +	{.compatible = "ti,dac5573", .data = (void *)quad_8bit},
> > > > +	{.compatible = "ti,dac6573", .data = (void *)quad_10bit},
> > > > +	{.compatible = "ti,dac7573", .data = (void *)quad_12bit},
> > > >  	{}
> > > >  };
> > > >  MODULE_DEVICE_TABLE(of, dac5571_of_id);    
> > >     
> >   
> 

Re: [PATCH v2] iio: dac: dac5571: Fix chip id detection for OF devices

[Laurent Pinchart]

On Sun, Mar 27, 2022 at 05:00:05PM +0100, Jonathan Cameron wrote:
> On Sun, 27 Mar 2022 16:59:01 +0100 Jonathan Cameron wrote:
> > On Sun, 27 Mar 2022 17:37:27 +0300 Laurent Pinchart wrote:
> > > On Sun, Mar 27, 2022 at 03:34:38PM +0100, Jonathan Cameron wrote:  
> > > > On Fri, 25 Mar 2022 01:43:40 +0200 Laurent Pinchart wrote:
> > > >     
> > > > > From: Jose Cazarin <joseespiriki@gmail.com>
> > > > > 
> > > > > When matching an OF device, the match mechanism tries all components of
> > > > > the compatible property. This can result with a device matched with a
> > > > > compatible string that isn't the first in the compatible list. For
> > > > > instance, with a compatible property set to
> > > > > 
> > > > >     compatible = "ti,dac081c081", "ti,dac5571";
> > > > > 
> > > > > the driver will match the second compatible string, as the first one
> > > > > isn't listed in the of_device_id table. The device will however be named
> > > > > "dac081c081" by the I2C core.
> > > > > 
> > > > > This causes an issue when identifying the chip. The probe function
> > > > > receives a i2c_device_id that comes from the module's I2C device ID
> > > > > table. There is no entry in that table for "dac081c081", which results
> > > > > in a NULL pointer passed to the probe function.
> > > > > 
> > > > > To fix this, add chip_id information in the data field of the OF device
> > > > > ID table, and retrieve it with of_device_get_match_data() for OF
> > > > > devices.    
> > > > 
> > > > You forgot to update the patch description for the change to device_get_match_data()
> > > > 
> > > > One other thing inline.    
> > > 
> > > Thank you for the comments. I agree with both. Would you like me to send
> > > a v3, or is this something you'd be happy fixing when applying the patch
> > > to your tree ?  
> > 
> > I've applied it how with those changes.  However, it's on my fixes-togreg branch
> now. 
> 
> I can't type on Sundays :)

Looks like I can't update commit messages on Fridays, so we're even ;-)

> > and I don't plan to push that out until after rc1 when I can rebase it on something
> > 'stable'.

Sure, no problem. There's no urgency, it's not v5.18 material.

> > > > > Signed-off-by: Jose Cazarin <joseespiriki@gmail.com>
> > > > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > > > ---
> > > > > Changes since v1:
> > > > > 
> > > > > - Use device_get_match_data()
> > > > > ---
> > > > >  drivers/iio/dac/ti-dac5571.c | 28 ++++++++++++++++++----------
> > > > >  1 file changed, 18 insertions(+), 10 deletions(-)
> > > > > 
> > > > > diff --git a/drivers/iio/dac/ti-dac5571.c b/drivers/iio/dac/ti-dac5571.c
> > > > > index 4a3b8d875518..4f50e31dffb0 100644
> > > > > --- a/drivers/iio/dac/ti-dac5571.c
> > > > > +++ b/drivers/iio/dac/ti-dac5571.c
> > > > > @@ -19,6 +19,7 @@
> > > > >  #include <linux/i2c.h>
> > > > >  #include <linux/module.h>
> > > > >  #include <linux/mod_devicetable.h>
> > > > > +#include <linux/property.h>
> > > > >  #include <linux/regulator/consumer.h>
> > > > >  
> > > > >  enum chip_id {
> > > > > @@ -311,6 +312,7 @@ static int dac5571_probe(struct i2c_client *client,
> > > > >  	const struct dac5571_spec *spec;
> > > > >  	struct dac5571_data *data;
> > > > >  	struct iio_dev *indio_dev;
> > > > > +	enum chip_id chip_id;
> > > > >  	int ret, i;
> > > > >  
> > > > >  	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> > > > > @@ -326,7 +328,13 @@ static int dac5571_probe(struct i2c_client *client,
> > > > >  	indio_dev->modes = INDIO_DIRECT_MODE;
> > > > >  	indio_dev->channels = dac5571_channels;
> > > > >  
> > > > > -	spec = &dac5571_spec[id->driver_data];
> > > > > +	if (dev->of_node)    
> > > > 
> > > > 	if (dev_fwnode(dev))
> > > >     
> > > > > +		chip_id = (uintptr_t)device_get_match_data(dev);
> > > > > +	else
> > > > > +		chip_id = id->driver_data;
> > > > > +
> > > > > +	spec = &dac5571_spec[chip_id];
> > > > > +
> > > > >  	indio_dev->num_channels = spec->num_channels;
> > > > >  	data->spec = spec;
> > > > >  
> > > > > @@ -385,15 +393,15 @@ static int dac5571_remove(struct i2c_client *i2c)
> > > > >  }
> > > > >  
> > > > >  static const struct of_device_id dac5571_of_id[] = {
> > > > > -	{.compatible = "ti,dac5571"},
> > > > > -	{.compatible = "ti,dac6571"},
> > > > > -	{.compatible = "ti,dac7571"},
> > > > > -	{.compatible = "ti,dac5574"},
> > > > > -	{.compatible = "ti,dac6574"},
> > > > > -	{.compatible = "ti,dac7574"},
> > > > > -	{.compatible = "ti,dac5573"},
> > > > > -	{.compatible = "ti,dac6573"},
> > > > > -	{.compatible = "ti,dac7573"},
> > > > > +	{.compatible = "ti,dac5571", .data = (void *)single_8bit},
> > > > > +	{.compatible = "ti,dac6571", .data = (void *)single_10bit},
> > > > > +	{.compatible = "ti,dac7571", .data = (void *)single_12bit},
> > > > > +	{.compatible = "ti,dac5574", .data = (void *)quad_8bit},
> > > > > +	{.compatible = "ti,dac6574", .data = (void *)quad_10bit},
> > > > > +	{.compatible = "ti,dac7574", .data = (void *)quad_12bit},
> > > > > +	{.compatible = "ti,dac5573", .data = (void *)quad_8bit},
> > > > > +	{.compatible = "ti,dac6573", .data = (void *)quad_10bit},
> > > > > +	{.compatible = "ti,dac7573", .data = (void *)quad_12bit},
> > > > >  	{}
> > > > >  };
> > > > >  MODULE_DEVICE_TABLE(of, dac5571_of_id);    

-- 
Regards,

Laurent Pinchart

Re: [PATCH v2] iio: dac: dac5571: Fix chip id detection for OF devices

[Andy Shevchenko]

On Fri, Mar 25, 2022 at 6:55 PM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> From: Jose Cazarin <joseespiriki@gmail.com>
>
> When matching an OF device, the match mechanism tries all components of
> the compatible property. This can result with a device matched with a
> compatible string that isn't the first in the compatible list. For
> instance, with a compatible property set to
>
>     compatible = "ti,dac081c081", "ti,dac5571";
>
> the driver will match the second compatible string, as the first one
> isn't listed in the of_device_id table. The device will however be named
> "dac081c081" by the I2C core.
>
> This causes an issue when identifying the chip. The probe function
> receives a i2c_device_id that comes from the module's I2C device ID
> table. There is no entry in that table for "dac081c081", which results
> in a NULL pointer passed to the probe function.
>
> To fix this, add chip_id information in the data field of the OF device
> ID table, and retrieve it with of_device_get_match_data() for OF
> devices.

It's a good fix, but...

...

> +       if (dev->of_node)

Why OF nodes?!

> +               chip_id = (uintptr_t)device_get_match_data(dev);
> +       else
> +               chip_id = id->driver_data;

> +       spec = &dac5571_spec[chip_id];


What I would rather expect here is

const ... *spec;

spec = device_get_match_data(dev);
if (!spec)
  spec = (const ...)id->driver_data;

And don't use enum in the driver data with ugly castings.

-- 
With Best Regards,
Andy Shevchenko