On Sun, 27 Mar 2022 17:37:27 +0300
Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> 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@xxxxxxxxx>
> > >
> > > 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@xxxxxxxxx>
> > > Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > > ---
> > > 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);
> >
>
