net: dsa: b53: hide legacy gpiolib usage on non-mips

The MIPS bcm53xx platform still uses the legacy gpiolib interfaces based
on gpio numbers, but other platforms do not.

Hide these interfaces inside of the existing #ifdef block and use the
modern interfaces in the common parts of the driver to allow building
it when the gpio_set_value() is left out of the kernel.

Reviewed-by: Jonas Gorski <jonas.gorski@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260601165716.648230-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/b53/b53_common.c

@@ -19,7 +19,7 @@
 
 #include <linux/delay.h>
 #include <linux/export.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/kernel.h>
 #include <linux/math.h>
 #include <linux/minmax.h>
@@ -965,17 +965,17 @@ EXPORT_SYMBOL(b53_configure_vlan);
 
 static void b53_switch_reset_gpio(struct b53_device *dev)
 {
-	int gpio = dev->reset_gpio;
+	struct gpio_desc *gpio = dev->reset_gpio;
 
-	if (gpio < 0)
+	if (IS_ERR(gpio))
 		return;
 
 	/* Reset sequence: RESET low(50ms)->high(20ms)
 	 */
-	gpio_set_value(gpio, 0);
+	gpiod_set_value(gpio, 0);
 	mdelay(50);
 
-	gpio_set_value(gpio, 1);
+	gpiod_set_value(gpio, 1);
 	mdelay(20);
 
 	dev->current_page = 0xff;
@@ -3092,7 +3092,6 @@ static int b53_switch_init(struct b53_device *dev)
 {
 	u32 chip_id = dev->chip_id;
 	unsigned int i;
-	int ret;
 
 	if (is63xx(dev))
 		chip_id = BCM63XX_DEVICE_ID;
@@ -3173,12 +3172,9 @@ static int b53_switch_init(struct b53_device *dev)
 		return -ENOMEM;
 
 	dev->reset_gpio = b53_switch_get_reset_gpio(dev);
-	if (dev->reset_gpio >= 0) {
-		ret = devm_gpio_request_one(dev->dev, dev->reset_gpio,
-					    GPIOF_OUT_INIT_HIGH, "robo_reset");
-		if (ret)
-			return ret;
-	}
+
+	if (PTR_ERR(dev->reset_gpio) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
 
 	return 0;
 }

drivers/net/dsa/b53/b53_priv.h

@@ -148,7 +148,7 @@ struct b53_device {
 	u8 duplex_reg;
 	u8 jumbo_pm_reg;
 	u8 jumbo_size_reg;
-	int reset_gpio;
+	struct gpio_desc *reset_gpio;
 	u8 num_arl_bins;
 	u16 num_arl_buckets;
 	enum dsa_tag_protocol tag_protocol;
@@ -467,23 +467,36 @@ static inline void b53_arl_search_read(struct b53_device *dev, u8 idx,
 #ifdef CONFIG_BCM47XX
 
 #include <linux/bcm47xx_nvram.h>
+#include <linux/gpio.h>
 #include <bcm47xx_board.h>
-static inline int b53_switch_get_reset_gpio(struct b53_device *dev)
+static inline struct gpio_desc *b53_switch_get_reset_gpio(struct b53_device *dev)
 {
 	enum bcm47xx_board board = bcm47xx_board_get();
+	int gpio, ret;
 
 	switch (board) {
 	case BCM47XX_BOARD_LINKSYS_WRT300NV11:
 	case BCM47XX_BOARD_LINKSYS_WRT310NV1:
-		return 8;
+		gpio = 8;
+		break;
 	default:
-		return bcm47xx_nvram_gpio_pin("robo_reset");
+		gpio = bcm47xx_nvram_gpio_pin("robo_reset");
 	}
+
+	if (!gpio_is_valid(gpio))
+		return ERR_PTR(-EINVAL);
+
+	ret = devm_gpio_request_one(dev->dev, gpio,
+				    GPIOF_OUT_INIT_HIGH, "robo_reset");
+	if (ret)
+		return ERR_PTR(ret);
+
+	return gpio_to_desc(gpio);
 }
 #else
-static inline int b53_switch_get_reset_gpio(struct b53_device *dev)
+static inline struct gpio_desc *b53_switch_get_reset_gpio(struct b53_device *dev)
 {
-	return -ENOENT;
+	return ERR_PTR(-ENODEV);
 }
 #endif