gpio: dwapb: Get clocks by means of resource managed interface

The kernel clock framework provides the resource managed version of
the clk_bulk_get() method. The only thing which needs to be also automated
is the clocks disable/unprepare procedure executed on the device removal.
It can be implemented by means of the custom action definition. After that
the clocks acquisition and release will be purely managed by the device
resources interface.
Signed-off-by: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200730152808.2955-10-Sergey.Semin@baikalelectronics.ruSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-dwapb.c

@@ -647,6 +647,36 @@ static int dwapb_get_reset(struct dwapb_gpio *gpio)
 	return devm_add_action_or_reset(gpio->dev, dwapb_assert_reset, gpio);
 }
 
+static void dwapb_disable_clks(void *data)
+{
+	struct dwapb_gpio *gpio = data;
+
+	clk_bulk_disable_unprepare(DWAPB_NR_CLOCKS, gpio->clks);
+}
+
+static int dwapb_get_clks(struct dwapb_gpio *gpio)
+{
+	int err;
+
+	/* Optional bus and debounce clocks */
+	gpio->clks[0].id = "bus";
+	gpio->clks[1].id = "db";
+	err = devm_clk_bulk_get_optional(gpio->dev, DWAPB_NR_CLOCKS,
+					 gpio->clks);
+	if (err) {
+		dev_err(gpio->dev, "Cannot get APB/Debounce clocks\n");
+		return err;
+	}
+
+	err = clk_bulk_prepare_enable(DWAPB_NR_CLOCKS, gpio->clks);
+	if (err) {
+		dev_err(gpio->dev, "Cannot enable APB/Debounce clocks\n");
+		return err;
+	}
+
+	return devm_add_action_or_reset(gpio->dev, dwapb_disable_clks, gpio);
+}
+
 static const struct of_device_id dwapb_of_match[] = {
 	{ .compatible = "snps,dw-apb-gpio", .data = (void *)0},
 	{ .compatible = "apm,xgene-gpio-v2", .data = (void *)GPIO_REG_OFFSET_V2},
@@ -699,21 +729,9 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
 	if (IS_ERR(gpio->regs))
 		return PTR_ERR(gpio->regs);
 
-	/* Optional bus and debounce clocks */
-	gpio->clks[0].id = "bus";
-	gpio->clks[1].id = "db";
-	err = devm_clk_bulk_get_optional(&pdev->dev, DWAPB_NR_CLOCKS,
-					 gpio->clks);
-	if (err) {
-		dev_err(&pdev->dev, "Cannot get APB/Debounce clocks\n");
-		return err;
-	}
-
-	err = clk_bulk_prepare_enable(DWAPB_NR_CLOCKS, gpio->clks);
-	if (err) {
-		dev_err(&pdev->dev, "Cannot enable APB/Debounce clocks\n");
+	err = dwapb_get_clks(gpio);
+	if (err)
 		return err;
-	}
 
 	gpio->flags = (uintptr_t)device_get_match_data(dev);
 
@@ -728,7 +746,6 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
 
 out_unregister:
 	dwapb_gpio_unregister(gpio);
-	clk_bulk_disable_unprepare(DWAPB_NR_CLOCKS, gpio->clks);
 
 	return err;
 }
@@ -738,7 +755,6 @@ static int dwapb_gpio_remove(struct platform_device *pdev)
 	struct dwapb_gpio *gpio = platform_get_drvdata(pdev);
 
 	dwapb_gpio_unregister(gpio);
-	clk_bulk_disable_unprepare(DWAPB_NR_CLOCKS, gpio->clks);
 
 	return 0;
 }