[PATCH v2] gpio: htc-egpio: use managed gpiochip registration

[Pengpeng Hou]

egpio_probe() registers each nested gpio_chip with gpiochip_add_data()
but ignores the return value.  If one registration fails, probe still
returns success even though one of the chips was not published to gpiolib.

Use devm_gpiochip_add_data() and fail probe if any chip registration
fails.  This lets devres unwind already registered chips and prevents the
driver from publishing a partially initialized device.

Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>
---
Changes since v1:
- Use dev_err_probe() for the gpiochip registration failure as requested by
  Bartosz Golaszewski.

 drivers/gpio/gpio-htc-egpio.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-htc-egpio.c b/drivers/gpio/gpio-htc-egpio.c
index 6b54474dc81c..17ca04b389cf 100644
--- a/drivers/gpio/gpio-htc-egpio.c
+++ b/drivers/gpio/gpio-htc-egpio.c
@@ -263,6 +263,7 @@ static int __init egpio_probe(struct platform_device *pdev)
 	struct gpio_chip  *chip;
 	unsigned int      irq, irq_end;
 	int               i;
+	int               ret;
 
 	/* Initialize ei data structure. */
 	ei = devm_kzalloc(&pdev->dev, sizeof(*ei), GFP_KERNEL);
@@ -340,7 +341,10 @@ static int __init egpio_probe(struct platform_device *pdev)
 		chip->base            = pdata->chip[i].gpio_base;
 		chip->ngpio           = pdata->chip[i].num_gpios;
 
-		gpiochip_add_data(chip, &ei->chip[i]);
+		ret = devm_gpiochip_add_data(&pdev->dev, chip, &ei->chip[i]);
+		if (ret)
+			return dev_err_probe(&pdev->dev, ret,
+					     "failed to register gpiochip %d\n", i);
 	}
 
 	/* Set initial pin values */
-- 
2.50.1