From 966a83df36c6f27476ac3501771422e7852098bc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <noltari@gmail.com>
Date: Sat, 14 Jun 2025 10:00:00 +0200
Subject: [PATCH] net: dsa: b53: ensure BCM5325 PHYs are enabled
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According to the datasheet, BCM5325 uses B53_PD_MODE_CTRL_25 register to
disable clocking to individual PHYs.
Only ports 1-4 can be enabled or disabled and the datasheet is explicit
about not toggling BIT(0) since it disables the PLL power and the switch.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20250614080000.1884236-15-noltari@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/dsa/b53/b53_common.c | 13 +++++++++++++
 drivers/net/dsa/b53/b53_regs.h   |  5 ++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -660,6 +660,19 @@ int b53_setup_port(struct dsa_switch *ds
 	if (dsa_is_user_port(ds, port))
 		b53_set_eap_mode(dev, port, EAP_MODE_SIMPLIFIED);
 
+	if (is5325(dev) &&
+	    in_range(port, 1, 4)) {
+		u8 reg;
+
+		b53_read8(dev, B53_CTRL_PAGE, B53_PD_MODE_CTRL_25, &reg);
+		reg &= ~PD_MODE_POWER_DOWN_PORT(0);
+		if (dsa_is_unused_port(ds, port))
+			reg |= PD_MODE_POWER_DOWN_PORT(port);
+		else
+			reg &= ~PD_MODE_POWER_DOWN_PORT(port);
+		b53_write8(dev, B53_CTRL_PAGE, B53_PD_MODE_CTRL_25, reg);
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL(b53_setup_port);
--- a/drivers/net/dsa/b53/b53_regs.h
+++ b/drivers/net/dsa/b53/b53_regs.h
@@ -103,8 +103,11 @@
 #define   PORT_OVERRIDE_SPEED_2000M	BIT(6) /* BCM5301X only, requires setting 1000M */
 #define   PORT_OVERRIDE_EN		BIT(7) /* Use the register contents */
 
-/* Power-down mode control */
+/* Power-down mode control (8 bit) */
 #define B53_PD_MODE_CTRL_25		0x0f
+#define  PD_MODE_PORT_MASK		0x1f
+/* Bit 0 also powers down the switch. */
+#define  PD_MODE_POWER_DOWN_PORT(i)	BIT(i)
 
 /* IP Multicast control (8 bit) */
 #define B53_IP_MULTICAST_CTRL		0x21
