[RFC PATCH net-next 5/6] net: dsa: b53: mmap: Clear resets on bcm63xx EPHYs

From: Kyle Hendry
Date: Fri Jun 20 2025 - 09:43:52 EST


Make sure the ephy resets aren't being held by setting
lowest bits in ephy control register.

Signed-off-by: Kyle Hendry <kylehendrydev@xxxxxxxxx>
---
drivers/net/dsa/b53/b53_mmap.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/net/dsa/b53/b53_mmap.c b/drivers/net/dsa/b53/b53_mmap.c
index 1bebf5b9826b..a4a2f2965bcc 100644
--- a/drivers/net/dsa/b53/b53_mmap.c
+++ b/drivers/net/dsa/b53/b53_mmap.c
@@ -24,9 +24,12 @@
#include <linux/mfd/syscon.h>
#include <linux/platform_device.h>
#include <linux/platform_data/b53.h>
+#include <linux/regmap.h>

#include "b53_priv.h"

+#define BCM63XX_EPHY_REG 0x3C
+
struct b53_phy_info {
u32 chip_id;
u32 mask;
@@ -253,6 +256,14 @@ static int b53_mmap_phy_write16(struct b53_device *dev, int addr, int reg,
return -EIO;
}

+static void bcm63xx_ephy_reset(struct regmap *regmap, int num_ephy)
+{
+ u32 mask = GENMASK((num_ephy - 1), 0);
+
+ /* Set lowest bits to deassert resets */
+ regmap_update_bits(regmap, BCM63XX_EPHY_REG, mask, mask);
+}
+
static const struct b53_io_ops b53_mmap_ops = {
.read8 = b53_mmap_read8,
.read16 = b53_mmap_read16,
@@ -345,6 +356,8 @@ static int b53_mmap_probe(struct platform_device *pdev)
break;
}
}
+ if (priv->phy_info)
+ bcm63xx_ephy_reset(priv->gpio_ctrl, priv->phy_info->num_ephy);
}

dev = b53_switch_alloc(&pdev->dev, &b53_mmap_ops, priv);
--
2.43.0