gpio: Setup parent device and get rid of unnecessary of_node assignment

Some of the drivers do not set parent device. This may lead to obstacles
during debugging or understanding the device relations from the Linux
point of view. Assign parent device for GPIO chips created by these
drivers.

While at it, let GPIO library to assign of_node from the parent device.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

drivers/gpio/gpio-bcm-kona.c

@@ -606,7 +606,7 @@ static int bcm_kona_gpio_probe(struct platform_device *pdev)
 
 	kona_gpio->pdev = pdev;
 	platform_set_drvdata(pdev, kona_gpio);
-	chip->of_node = dev->of_node;
+	chip->parent = dev;
 	chip->ngpio = kona_gpio->num_bank * GPIO_PER_BANK;
 
 	kona_gpio->irq_domain = irq_domain_add_linear(dev->of_node,

drivers/gpio/gpio-creg-snps.c

@@ -163,12 +163,12 @@ static int creg_gpio_probe(struct platform_device *pdev)
 
 	spin_lock_init(&hcg->lock);
 
+	hcg->gc.parent = dev;
 	hcg->gc.label = dev_name(dev);
 	hcg->gc.base = -1;
 	hcg->gc.ngpio = ngpios;
 	hcg->gc.set = creg_gpio_set;
 	hcg->gc.direction_output = creg_gpio_dir_out;
-	hcg->gc.of_node = dev->of_node;
 
 	ret = devm_gpiochip_add_data(dev, &hcg->gc, hcg);
 	if (ret)

drivers/gpio/gpio-lpc32xx.c

@@ -512,10 +512,10 @@ static int lpc32xx_gpio_probe(struct platform_device *pdev)
 		return PTR_ERR(reg_base);
 
 	for (i = 0; i < ARRAY_SIZE(lpc32xx_gpiochip); i++) {
+		lpc32xx_gpiochip[i].chip.parent = &pdev->dev;
 		if (pdev->dev.of_node) {
 			lpc32xx_gpiochip[i].chip.of_xlate = lpc32xx_of_xlate;
 			lpc32xx_gpiochip[i].chip.of_gpio_n_cells = 3;
-			lpc32xx_gpiochip[i].chip.of_node = pdev->dev.of_node;
 			lpc32xx_gpiochip[i].reg_base = reg_base;
 		}
 		devm_gpiochip_add_data(&pdev->dev, &lpc32xx_gpiochip[i].chip,

drivers/gpio/gpio-pxa.c

@@ -343,8 +343,7 @@ static int pxa_gpio_of_xlate(struct gpio_chip *gc,
 }
 #endif
 
-static int pxa_init_gpio_chip(struct pxa_gpio_chip *pchip, int ngpio,
-			      struct device_node *np, void __iomem *regbase)
+static int pxa_init_gpio_chip(struct pxa_gpio_chip *pchip, int ngpio, void __iomem *regbase)
 {
 	int i, gpio, nbanks = DIV_ROUND_UP(ngpio, 32);
 	struct pxa_gpio_bank *bank;
@@ -354,6 +353,7 @@ static int pxa_init_gpio_chip(struct pxa_gpio_chip *pchip, int ngpio,
 	if (!pchip->banks)
 		return -ENOMEM;
 
+	pchip->chip.parent = pchip->dev;
 	pchip->chip.label = "gpio-pxa";
 	pchip->chip.direction_input  = pxa_gpio_direction_input;
 	pchip->chip.direction_output = pxa_gpio_direction_output;
@@ -365,7 +365,6 @@ static int pxa_init_gpio_chip(struct pxa_gpio_chip *pchip, int ngpio,
 	pchip->chip.free = gpiochip_generic_free;
 
 #ifdef CONFIG_OF_GPIO
-	pchip->chip.of_node = np;
 	pchip->chip.of_xlate = pxa_gpio_of_xlate;
 	pchip->chip.of_gpio_n_cells = 2;
 #endif
@@ -675,8 +674,7 @@ static int pxa_gpio_probe(struct platform_device *pdev)
 	}
 
 	/* Initialize GPIO chips */
-	ret = pxa_init_gpio_chip(pchip, pxa_last_gpio + 1, pdev->dev.of_node,
-				 gpio_reg_base);
+	ret = pxa_init_gpio_chip(pchip, pxa_last_gpio + 1, gpio_reg_base);
 	if (ret) {
 		clk_put(clk);
 		return ret;