On Sat, 19 Sep 2020 16:14:40 +0100 Jonathan Cameron <[email protected]> wrote:
> On Fri, 18 Sep 2020 12:33:56 +0300 > Cristian Pop <[email protected]> wrote: > > > This is a demo usage of new "label" attribute for channel. > While I can see this is a demo in someways, I assume we also have > a valid usecase for doing this beyond as a demo! > > So perhaps rephrase that intro. I also forgot to say that you also need to update the dt-bindings for this driver. I've just committed a patch converting them to yaml so work on top of that. Thanks Jonathan > > > > > Signed-off-by: Cristian Pop <[email protected]> > > --- > > Changes in V5: > > Create a separate patch file for this commit > > drivers/iio/adc/ad7768-1.c | 49 ++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 49 insertions(+) > > > > diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c > > index 0d132708c429..5ca9f9febb5a 100644 > > --- a/drivers/iio/adc/ad7768-1.c > > +++ b/drivers/iio/adc/ad7768-1.c > > @@ -161,6 +161,7 @@ struct ad7768_state { > > struct completion completion; > > struct iio_trigger *trig; > > struct gpio_desc *gpio_sync_in; > > + const char **labels; > > /* > > * DMA (thus cache coherency maintenance) requires the > > * transfer buffers to live in their own cache lines. > > @@ -407,6 +408,14 @@ static int ad7768_write_raw(struct iio_dev *indio_dev, > > } > > } > > > > +static int ad7768_read_label(struct iio_dev *indio_dev, > > + const struct iio_chan_spec *chan, char *label) > > +{ > > + struct ad7768_state *st = iio_priv(indio_dev); > > + > > + return sprintf(label, "%s\n", st->labels[chan->channel]); > > +} > > + > > static struct attribute *ad7768_attributes[] = { > > &iio_dev_attr_sampling_frequency_available.dev_attr.attr, > > NULL > > @@ -420,6 +429,7 @@ static const struct iio_info ad7768_info = { > > .attrs = &ad7768_group, > > .read_raw = &ad7768_read_raw, > > .write_raw = &ad7768_write_raw, > > + .read_label = ad7768_read_label, > > .debugfs_reg_access = &ad7768_reg_access, > > }; > > > > @@ -538,6 +548,41 @@ static void ad7768_clk_disable(void *data) > > clk_disable_unprepare(st->mclk); > > } > > > > +static int ad7768_set_channel_label(struct iio_dev *indio_dev, > > + int num_channels) > > +{ > > + struct ad7768_state *st = iio_priv(indio_dev); > > + struct device *device = indio_dev->dev.parent; > > + struct fwnode_handle *fwnode; > > + struct fwnode_handle *child; > > + const char *label; > > + int crt_ch = 0; > > + > > + st->labels = devm_kcalloc(indio_dev->dev.parent, > > + num_channels, > > + sizeof(**st->labels), > > I think that ends up being the size of a single character which isn't > the intent. I assume aim is a suitable sized array of pointers to > strings which we will fill in later? > > If so we can probably just use a static sized array as the maximum > number of channels is well constrained. In this particular driver > that is 1 I think! > > > + GFP_KERNEL); > > + > > + if (!st->labels) > > + return -ENOMEM; > > + > > + fwnode = dev_fwnode(device); > > + fwnode_for_each_child_node(fwnode, child) { > > + if (fwnode_property_read_u32(child, "reg", &crt_ch)) > > + continue; > > + > > + if (crt_ch >= num_channels) > > + continue; > > + > > + if (fwnode_property_read_string(child, "label", &label)) > > + continue; > > + > > + st->labels[crt_ch] = label; > > + } > > + > > + return 0; > > +} > > + > > static int ad7768_probe(struct spi_device *spi) > > { > > struct ad7768_state *st; > > @@ -611,6 +656,10 @@ static int ad7768_probe(struct spi_device *spi) > > > > init_completion(&st->completion); > > > > + ret = ad7768_set_channel_label(indio_dev, ARRAY_SIZE(ad7768_channels)); > > + if (ret) > > + return ret; > > + > > ret = devm_request_irq(&spi->dev, spi->irq, > > &ad7768_interrupt, > > IRQF_TRIGGER_RISING | IRQF_ONESHOT, >
