gpio: mvebu: Make use of devm_pwmchip_alloc() function

This prepares the pwm sub-driver to further changes of the pwm core
outlined in the commit introducing devm_pwmchip_alloc(). There is no
intended semantical change and the driver should behave as before.

Acked-by: Linus Walleij <[e-mail]>
Link: https://lore.kernel.org/r/2edc3ad[e-mail]
Signed-off-by: Uwe Kleine-König <[e-mail]>

drivers/gpio/gpio-mvebu.c

···
 	u32			 offset;
 	unsigned long		 clk_rate;
 	struct gpio_desc	*gpiod;
-	struct pwm_chip		 chip;
 	spinlock_t		 lock;
 	struct mvebu_gpio_chip	*mvchip;
 
···
  */
 static struct mvebu_pwm *to_mvebu_pwm(struct pwm_chip *chip)
 {
-	return container_of(chip, struct mvebu_pwm, chip);
+	return pwmchip_get_drvdata(chip);
 }
 
 static int mvebu_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
···
 {
 	struct device *dev = &pdev->dev;
 	struct mvebu_pwm *mvpwm;
+	struct pwm_chip *chip;
 	void __iomem *base;
 	u32 offset;
 	u32 set;
···
 	if (IS_ERR(mvchip->clk))
 		return PTR_ERR(mvchip->clk);
 
-	mvpwm = devm_kzalloc(dev, sizeof(struct mvebu_pwm), GFP_KERNEL);
-	if (!mvpwm)
-		return -ENOMEM;
+	chip = devm_pwmchip_alloc(dev, mvchip->chip.ngpio, sizeof(*mvpwm));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	mvpwm = to_mvebu_pwm(chip);
+
 	mvchip->mvpwm = mvpwm;
 	mvpwm->mvchip = mvchip;
 	mvpwm->offset = offset;
···
 		return -EINVAL;
 	}
 
-	mvpwm->chip.dev = dev;
-	mvpwm->chip.ops = &mvebu_pwm_ops;
-	mvpwm->chip.npwm = mvchip->chip.ngpio;
+	chip->ops = &mvebu_pwm_ops;
 
 	spin_lock_init(&mvpwm->lock);
 
-	return devm_pwmchip_add(dev, &mvpwm->chip);
+	return devm_pwmchip_add(dev, chip);
 }
 
 #ifdef CONFIG_DEBUG_FS