iio: adc: ad7606: move the software mode configuration

BugLink: https://bugs.launchpad.net/bugs/2115266

[ Upstream commit f2a62931b39478c98f977caf299df5bc072f38e0 ]

This is a preparation for the intoduction of the sofware functions in
the iio backend version of the driver.
The software mode configuration must be executed once the channels are
configured, and the number of channels is known. This is not the case
before iio-backend's configuration is called, and iio backend version of
the driver does not have a timestamp channel.
Also the sw_mode_config callback is configured during the iio-backend
configuration.
For clarity purpose, I moved the entire block instead of just the
concerned function calls.

Signed-off-by: Guillaume Stols <gstols@baylibre.com>
Link: https://patch.msgid.link/20250210-wip-bl-ad7606_add_backend_sw_mode-v4-2-160df18b1da7@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Stable-dep-of: 5257d80e22bf ("iio: adc: ad7606: check for NULL before calling sw_mode_config()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

Author: gstols

drivers/iio/adc/ad7606.c

@@ -1246,17 +1246,6 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 			return -ERESTARTSYS;
 	}
 
-	st->write_scale = ad7606_write_scale_hw;
-	st->write_os = ad7606_write_os_hw;
-
-	ret = ad7606_sw_mode_setup(indio_dev);
-	if (ret)
-		return ret;
-
-	ret = ad7606_chan_scales_setup(indio_dev);
-	if (ret)
-		return ret;
-
 	/* If convst pin is not defined, setup PWM. */
 	if (!st->gpio_convst) {
 		st->cnvst_pwm = devm_pwm_get(dev, NULL);
@@ -1334,6 +1323,17 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 			return ret;
 	}
 
+	st->write_scale = ad7606_write_scale_hw;
+	st->write_os = ad7606_write_os_hw;
+
+	ret = ad7606_sw_mode_setup(indio_dev);
+	if (ret)
+		return ret;
+
+	ret = ad7606_chan_scales_setup(indio_dev);
+	if (ret)
+		return ret;
+
 	return devm_iio_device_register(dev, indio_dev);
 }
 EXPORT_SYMBOL_NS_GPL(ad7606_probe, "IIO_AD7606");