Re: [PATCH v3 12/14] gpio: regmap: Add optional runtime PM support

On Fri, 14 Aug 2026 11:34:13 +0300
Andy Shevchenko [off-list ref] wrote:

On Thu, Aug 13, 2026 at 03:57:05PM +0200, Janani Sunil wrote:

quoted

Some gpio-regmap consumers share their regmap with a parent device that
may be runtime suspended. GPIO register accesses must resume that device
first.

Add an optional pm_dev field and acquire it before register translation
or access. Release it using runtime autosuspend after each operation.
Keep the device active across the complete direction-output sequence and
propagate failure when setting the initial output value.  

...

quoted

 static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
 {
 	struct gpio_regmap *gpio = gpiochip_get_data(chip);  

quoted

 
-	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	ret = gpio_regmap_runtime_get(gpio);
 	if (ret)
 		return ret;
 
+	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	if (ret)
+		goto out_pm_put;
+
 	/* ensure we don't spoil any register cache with pin input values */
 	if (gpio->reg_dat_base == gpio->reg_set_base) {
 		ret = regmap_read_bypassed(gpio->regmap, reg, &val);
 		if (ret)
-			return ret;
+			goto out_pm_put;
 
-		return !!(val & mask);
+		ret = !!(val & mask);
+	} else {
+		ret = regmap_test_bits(gpio->regmap, reg, mask);
 	}
 
-	return regmap_test_bits(gpio->regmap, reg, mask);
+out_pm_put:
+	gpio_regmap_runtime_put(gpio);
+	return ret;
 }  

Instead of adding ugly goto:s, I would rather define the guard and acquire and
use in the same way as other PM_RUNTIME_ACQUIRE*() work.

Excellent point Andy.

I was thinking exactly this when looking at v2 just now (and feeling guilty for
being late to the discussion!)

Would need a local GPIO specific variant but that is easy to do - just copy
the way PM_RUNTIME_ACQUIRE*() works.

Given how much it will reduce the code churn + result in a more elegant result
for me this is a necessary change rather than a nice to have.

Thanks,

Jonathan