board: sifive: unmatched: refine GEMGXL initialized function in SPL

Create a new function spl_reset_device_by_gpio to reset the device
whose reset pin is connected to the GPIO. Then, using this function
to initialize GEMGXL.
Signed-off-by: NVincent Chen <vincent.chen@sifive.com>
Reviewed-by: NLeo Yu-Chi Liang <ycliang@andestech.com>

board/sifive/unmatched/spl.c

@@ -22,43 +22,63 @@
 #define MODE_SELECT_SD		0xb
 #define MODE_SELECT_MASK	GENMASK(3, 0)
 
-int spl_board_init_f(void)
+static inline int spl_reset_device_by_gpio(const char *label, int pin, int low_width)
 {
 	int ret;
 
-	ret = spl_soc_init();
+	ret = gpio_request(pin, label);
 	if (ret) {
-		debug("HiFive Unmatched FU740 SPL init failed: %d\n", ret);
+		debug("%s gpio request failed: %d\n", label, ret);
+		return ret;
+	}
+
+	ret = gpio_direction_output(pin, 1);
+	if (ret) {
+		debug("%s gpio direction set failed: %d\n", label, ret);
 		return ret;
 	}
 
+	udelay(1);
+
+	gpio_set_value(pin, 0);
+	udelay(low_width);
+	gpio_set_value(pin, 1);
+
+	return ret;
+}
+
+static inline int spl_gemgxl_init(void)
+{
+	int ret;
 	/*
 	 * GEMGXL init VSC8541 PHY reset sequence;
 	 * leave pull-down active for 2ms
 	 */
 	udelay(2000);
-	ret = gpio_request(GEM_PHY_RESET, "gem_phy_reset");
+	ret = spl_reset_device_by_gpio("gem_phy_reset", GEM_PHY_RESET, 1);
+	mdelay(15);
+
+	return ret;
+}
+
+int spl_board_init_f(void)
+{
+	int ret;
+
+	ret = spl_soc_init();
 	if (ret) {
-		debug("gem_phy_reset gpio request failed: %d\n", ret);
-		return ret;
+		debug("HiFive Unmatched FU740 SPL init failed: %d\n", ret);
+		goto end;
 	}
 
-	/* Set GPIO 12 (PHY NRESET) */
-	ret = gpio_direction_output(GEM_PHY_RESET, 1);
+	ret = spl_gemgxl_init();
 	if (ret) {
-		debug("gem_phy_reset gpio direction set failed: %d\n", ret);
-		return ret;
+		debug("Gigabit ethernet PHY (VSC8541) init failed: %d\n", ret);
+		goto end;
 	}
 
-	udelay(1);
-
-	/* Reset PHY again to enter unmanaged mode */
-	gpio_set_value(GEM_PHY_RESET, 0);
-	udelay(1);
-	gpio_set_value(GEM_PHY_RESET, 1);
-	mdelay(15);
-
-	return 0;
+end:
+	return ret;
 }
 
 u32 spl_boot_device(void)