iio: adc: ad7768-1: Add channel labels.

For better identification of the channels.

Signed-off-by: Cristian Pop <cristian.pop@analog.com>
Link: https://lore.kernel.org/r/20200928090959.88842-3-cristian.pop@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c
index 0e93b0766eb45b5d87464ef395998d7c2a141533..5c0cbee032308376c395c3996bfea65eb8944e64 100644 (file)
--- 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[ARRAY_SIZE(ad7768_channels)];
        /*
         * 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,
 };
 
@@ -532,6 +542,33 @@ 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;
+
+       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;
@@ -604,6 +641,10 @@ 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,