power: supply: ab8500: Use dev_err_probe() for IIO channels

The code obtaining the ADC channels is outdated: it is
trying to work around the IIO subsystem not returning
the right -EPROBE_DEFER error code. Fix this up
by using the dev_err_probe() helper so we defer silently
where appropriate and not bail out if the IIO core
returns -EPROBE_DEFER as happens now.

Cc: Marcus Cooper <codekipper@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/ab8500_btemp.c

@@ -1023,17 +1023,15 @@ static int ab8500_btemp_probe(struct platform_device *pdev)
 	/* Get ADC channels */
 	di->btemp_ball = devm_iio_channel_get(dev, "btemp_ball");
 	if (IS_ERR(di->btemp_ball)) {
-		if (PTR_ERR(di->btemp_ball) == -ENODEV)
-			return -EPROBE_DEFER;
-		dev_err(dev, "failed to get BTEMP BALL ADC channel\n");
-		return PTR_ERR(di->btemp_ball);
+		ret = dev_err_probe(dev, PTR_ERR(di->btemp_ball),
+				    "failed to get BTEMP BALL ADC channel\n");
+		return ret;
 	}
 	di->bat_ctrl = devm_iio_channel_get(dev, "bat_ctrl");
 	if (IS_ERR(di->bat_ctrl)) {
-		if (PTR_ERR(di->bat_ctrl) == -ENODEV)
-			return -EPROBE_DEFER;
-		dev_err(dev, "failed to get BAT CTRL ADC channel\n");
-		return PTR_ERR(di->bat_ctrl);
+		ret = dev_err_probe(dev, PTR_ERR(di->bat_ctrl),
+				    "failed to get BAT CTRL ADC channel\n");
+		return ret;
 	}
 
 	di->initialized = false;

drivers/power/supply/ab8500_charger.c

@@ -3375,36 +3375,29 @@ static int ab8500_charger_probe(struct platform_device *pdev)
 	di->parent = dev_get_drvdata(pdev->dev.parent);
 
 	/* Get ADC channels */
-	di->adc_main_charger_v = devm_iio_channel_get(dev,
-						      "main_charger_v");
+	di->adc_main_charger_v = devm_iio_channel_get(dev, "main_charger_v");
 	if (IS_ERR(di->adc_main_charger_v)) {
-		if (PTR_ERR(di->adc_main_charger_v) == -ENODEV)
-			return -EPROBE_DEFER;
-		dev_err(dev, "failed to get ADC main charger voltage\n");
-		return PTR_ERR(di->adc_main_charger_v);
+		ret = dev_err_probe(dev, PTR_ERR(di->adc_main_charger_v),
+				    "failed to get ADC main charger voltage\n");
+		return ret;
 	}
-	di->adc_main_charger_c = devm_iio_channel_get(dev,
-						      "main_charger_c");
+	di->adc_main_charger_c = devm_iio_channel_get(dev, "main_charger_c");
 	if (IS_ERR(di->adc_main_charger_c)) {
-		if (PTR_ERR(di->adc_main_charger_c) == -ENODEV)
-			return -EPROBE_DEFER;
-		dev_err(dev, "failed to get ADC main charger current\n");
-		return PTR_ERR(di->adc_main_charger_c);
+		ret = dev_err_probe(dev, PTR_ERR(di->adc_main_charger_c),
+				    "failed to get ADC main charger current\n");
+		return ret;
 	}
 	di->adc_vbus_v = devm_iio_channel_get(dev, "vbus_v");
 	if (IS_ERR(di->adc_vbus_v)) {
-		if (PTR_ERR(di->adc_vbus_v) == -ENODEV)
-			return -EPROBE_DEFER;
-		dev_err(dev, "failed to get ADC USB charger voltage\n");
-		return PTR_ERR(di->adc_vbus_v);
+		ret = dev_err_probe(dev, PTR_ERR(di->adc_vbus_v),
+				    "failed to get ADC USB charger voltage\n");
+		return ret;
 	}
-	di->adc_usb_charger_c = devm_iio_channel_get(dev,
-						     "usb_charger_c");
+	di->adc_usb_charger_c = devm_iio_channel_get(dev, "usb_charger_c");
 	if (IS_ERR(di->adc_usb_charger_c)) {
-		if (PTR_ERR(di->adc_usb_charger_c) == -ENODEV)
-			return -EPROBE_DEFER;
-		dev_err(dev, "failed to get ADC USB charger current\n");
-		return PTR_ERR(di->adc_usb_charger_c);
+		ret = dev_err_probe(dev, PTR_ERR(di->adc_usb_charger_c),
+				    "failed to get ADC USB charger current\n");
+		return ret;
 	}
 
 	/* initialize lock */

drivers/power/supply/ab8500_fg.c

@@ -3059,10 +3059,9 @@ static int ab8500_fg_probe(struct platform_device *pdev)
 
 	di->main_bat_v = devm_iio_channel_get(dev, "main_bat_v");
 	if (IS_ERR(di->main_bat_v)) {
-		if (PTR_ERR(di->main_bat_v) == -ENODEV)
-			return -EPROBE_DEFER;
-		dev_err(dev, "failed to get main battery ADC channel\n");
-		return PTR_ERR(di->main_bat_v);
+		ret = dev_err_probe(dev, PTR_ERR(di->main_bat_v),
+				    "failed to get main battery ADC channel\n");
+		return ret;
 	}
 
 	psy_cfg.supplied_to = supply_interface;