[PATCH net-next v10 0/4] net: dsa: motorcomm: Add LED support

[PATCH net-next v10 0/4] net: dsa: motorcomm: Add LED support

[David Yang]

LEDs can be described in the device tree using the standard LED node
notation. Currently, only parallel mode and strict 1:1 mapping (i.e. the
HW default) are supported.

v9: https://lore.kernel.org/r/20260726162731.1005803-1-mmyangfl@gmail.com
  - LED initialization sequence adjusted
  - add DT description
v8: https://lore.kernel.org/r/20260725045008.858692-1-mmyangfl@gmail.com
  - limit the led port number
v7: https://lore.kernel.org/r/20260723195335.806002-1-mmyangfl@gmail.com
  - rebase
v6: https://lore.kernel.org/r/20260709014812.1158178-1-mmyangfl@gmail.com
  - per-port initialization support
v5: https://lore.kernel.org/r/20260707064752.1030345-1-mmyangfl@gmail.com
  - improve trigger selection
v4: https://lore.kernel.org/r/20260703165241.542195-1-mmyangfl@gmail.com
  - fix some reg op typos
v3: https://lore.kernel.org/r/20260701155519.273212-1-mmyangfl@gmail.com
  - fix null pointer dereference
  - support polarity auto-configuration
v2: https://lore.kernel.org/r/20260629183137.541341-1-mmyangfl@gmail.com
  - allocate LED structures only
  - eliminate double locking
v1: https://lore.kernel.org/r/20260618202716.2166450-1-mmyangfl@gmail.com
  - set up polarity correctly
  - do not set up .brightness_get() to prevent dead lo

David Yang (4):
  net: dsa: motorcomm: Move to subdirectory
  net: dsa: motorcomm: Split SMI module
  net: dsa: motorcomm: Add LED support
  dt-bindings: net: dsa: yt921x: Add LEDs definition example

 .../bindings/net/dsa/motorcomm,yt921x.yaml    |  23 +
 MAINTAINERS                                   |   2 +-
 drivers/net/dsa/Kconfig                       |  10 +-
 drivers/net/dsa/Makefile                      |   2 +-
 drivers/net/dsa/motorcomm/Kconfig             |  17 +
 drivers/net/dsa/motorcomm/Makefile            |   5 +
 .../net/dsa/{yt921x.c => motorcomm/chip.c}    | 222 +-----
 .../net/dsa/{yt921x.h => motorcomm/chip.h}    |  12 +
 drivers/net/dsa/motorcomm/leds.c              | 654 ++++++++++++++++++
 drivers/net/dsa/motorcomm/leds.h              | 121 ++++
 drivers/net/dsa/motorcomm/smi.c               | 157 +++++
 drivers/net/dsa/motorcomm/smi.h               |  92 +++
 12 files changed, 1098 insertions(+), 219 deletions(-)
 create mode 100644 drivers/net/dsa/motorcomm/Kconfig
 create mode 100644 drivers/net/dsa/motorcomm/Makefile
 rename drivers/net/dsa/{yt921x.c => motorcomm/chip.c} (96%)
 rename drivers/net/dsa/{yt921x.h => motorcomm/chip.h} (99%)
 create mode 100644 drivers/net/dsa/motorcomm/leds.c
 create mode 100644 drivers/net/dsa/motorcomm/leds.h
 create mode 100644 drivers/net/dsa/motorcomm/smi.c
 create mode 100644 drivers/net/dsa/motorcomm/smi.h

-- 
2.53.0

[PATCH net-next v10 1/4] net: dsa: motorcomm: Move to subdirectory

[David Yang]

yt921x is already the longest single-file DSA driver, so it's time to
split it into parts.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 MAINTAINERS                                    |  2 +-
 drivers/net/dsa/Kconfig                        | 10 ++--------
 drivers/net/dsa/Makefile                       |  2 +-
 drivers/net/dsa/motorcomm/Kconfig              |  8 ++++++++
 drivers/net/dsa/motorcomm/Makefile             |  3 +++
 drivers/net/dsa/{yt921x.c => motorcomm/chip.c} |  2 +-
 drivers/net/dsa/{yt921x.h => motorcomm/chip.h} |  0
 7 files changed, 16 insertions(+), 11 deletions(-)
 create mode 100644 drivers/net/dsa/motorcomm/Kconfig
 create mode 100644 drivers/net/dsa/motorcomm/Makefile
 rename drivers/net/dsa/{yt921x.c => motorcomm/chip.c} (99%)
 rename drivers/net/dsa/{yt921x.h => motorcomm/chip.h} (100%)

diff --git a/MAINTAINERS b/MAINTAINERS
index 991460050da7..55cc5ac0e86f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18256,7 +18256,7 @@ M:	David Yang <mmyangfl@gmail.com>
 L:	netdev@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/net/dsa/motorcomm,yt921x.yaml
-F:	drivers/net/dsa/yt921x.*
+F:	drivers/net/dsa/motorcomm/
 F:	net/dsa/tag_yt921x.c
 
 MOXA SMARTIO/INDUSTIO/INTELLIO SERIAL CARD
diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
index 4ab567c5bbaf..98e9bbe47de7 100644
--- a/drivers/net/dsa/Kconfig
+++ b/drivers/net/dsa/Kconfig
@@ -72,6 +72,8 @@ config NET_DSA_MV88E6060
 
 source "drivers/net/dsa/microchip/Kconfig"
 
+source "drivers/net/dsa/motorcomm/Kconfig"
+
 source "drivers/net/dsa/mv88e6xxx/Kconfig"
 
 source "drivers/net/dsa/mxl862xx/Kconfig"
@@ -158,12 +160,4 @@ config NET_DSA_VITESSE_VSC73XX_PLATFORM
 	  This enables support for the Vitesse VSC7385, VSC7388, VSC7395
 	  and VSC7398 SparX integrated ethernet switches, connected over
 	  a CPU-attached address bus and work in memory-mapped I/O mode.
-
-config NET_DSA_YT921X
-	tristate "Motorcomm YT9215 ethernet switch chip support"
-	select NET_DSA_TAG_YT921X
-	select NET_IEEE8021Q_HELPERS if DCB
-	help
-	  This enables support for the Motorcomm YT9215 ethernet switch
-	  chip.
 endmenu
diff --git a/drivers/net/dsa/Makefile b/drivers/net/dsa/Makefile
index d2975badffc0..138225baa4d5 100644
--- a/drivers/net/dsa/Makefile
+++ b/drivers/net/dsa/Makefile
@@ -14,11 +14,11 @@ obj-$(CONFIG_NET_DSA_SMSC_LAN9303_MDIO) += lan9303_mdio.o
 obj-$(CONFIG_NET_DSA_VITESSE_VSC73XX) += vitesse-vsc73xx-core.o
 obj-$(CONFIG_NET_DSA_VITESSE_VSC73XX_PLATFORM) += vitesse-vsc73xx-platform.o
 obj-$(CONFIG_NET_DSA_VITESSE_VSC73XX_SPI) += vitesse-vsc73xx-spi.o
-obj-$(CONFIG_NET_DSA_YT921X) += yt921x.o
 obj-y				+= b53/
 obj-y				+= hirschmann/
 obj-y				+= lantiq/
 obj-y				+= microchip/
+obj-y				+= motorcomm/
 obj-y				+= mv88e6xxx/
 obj-y				+= mxl862xx/
 obj-y				+= netc/
diff --git a/drivers/net/dsa/motorcomm/Kconfig b/drivers/net/dsa/motorcomm/Kconfig
new file mode 100644
index 000000000000..1fddd386f866
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/Kconfig
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: ISC
+config NET_DSA_YT921X
+	tristate "Motorcomm YT9215 ethernet switch chip support"
+	select NET_DSA_TAG_YT921X
+	select NET_IEEE8021Q_HELPERS if DCB
+	help
+	  This enables support for the Motorcomm YT9215 ethernet switch
+	  chip.
diff --git a/drivers/net/dsa/motorcomm/Makefile b/drivers/net/dsa/motorcomm/Makefile
new file mode 100644
index 000000000000..afd03be9fa35
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: ISC
+obj-$(CONFIG_NET_DSA_YT921X) += yt921x.o
+yt921x-objs := chip.o
diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/motorcomm/chip.c
similarity index 99%
rename from drivers/net/dsa/yt921x.c
rename to drivers/net/dsa/motorcomm/chip.c
index 159b16606f6c..f070732845eb 100644
--- a/drivers/net/dsa/yt921x.c
+++ b/drivers/net/dsa/motorcomm/chip.c
@@ -26,7 +26,7 @@
 #include <net/ieee8021q.h>
 #include <net/pkt_cls.h>
 
-#include "yt921x.h"
+#include "chip.h"
 
 struct yt921x_mib_desc {
 	unsigned int size;
diff --git a/drivers/net/dsa/yt921x.h b/drivers/net/dsa/motorcomm/chip.h
similarity index 100%
rename from drivers/net/dsa/yt921x.h
rename to drivers/net/dsa/motorcomm/chip.h
-- 
2.53.0

[PATCH net-next v10 2/4] net: dsa: motorcomm: Split SMI module

[David Yang]

SMI operations are going to be used across different modules. Minor
changes are applied to fix build errors.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/dsa/motorcomm/Makefile |   1 +
 drivers/net/dsa/motorcomm/chip.c   | 207 +----------------------------
 drivers/net/dsa/motorcomm/smi.c    | 157 ++++++++++++++++++++++
 drivers/net/dsa/motorcomm/smi.h    |  92 +++++++++++++
 4 files changed, 251 insertions(+), 206 deletions(-)
 create mode 100644 drivers/net/dsa/motorcomm/smi.c
 create mode 100644 drivers/net/dsa/motorcomm/smi.h

diff --git a/drivers/net/dsa/motorcomm/Makefile b/drivers/net/dsa/motorcomm/Makefile
index afd03be9fa35..6cea5313a444 100644
--- a/drivers/net/dsa/motorcomm/Makefile
+++ b/drivers/net/dsa/motorcomm/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: ISC
 obj-$(CONFIG_NET_DSA_YT921X) += yt921x.o
 yt921x-objs := chip.o
+yt921x-objs += smi.o
diff --git a/drivers/net/dsa/motorcomm/chip.c b/drivers/net/dsa/motorcomm/chip.c
index f070732845eb..6dee25b6754a 100644
--- a/drivers/net/dsa/motorcomm/chip.c
+++ b/drivers/net/dsa/motorcomm/chip.c
@@ -13,7 +13,6 @@
 #include <linux/if_bridge.h>
 #include <linux/if_hsr.h>
 #include <linux/if_vlan.h>
-#include <linux/iopoll.h>
 #include <linux/mdio.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -27,6 +26,7 @@
 #include <net/pkt_cls.h>
 
 #include "chip.h"
+#include "smi.h"
 
 struct yt921x_mib_desc {
 	unsigned int size;
@@ -155,9 +155,6 @@ static const struct yt921x_info yt921x_infos[] = {
 
 #define YT921X_VID_UNWARE	4095
 
-#define YT921X_POLL_SLEEP_US	10000
-#define YT921X_POLL_TIMEOUT_US	100000
-
 /* The interval should be small enough to avoid overflow of 32bit MIBs.
  *
  * Until we can read MIBs from stats64 call directly (i.e. sleep
@@ -196,208 +193,6 @@ static u32 ethaddr_lo2_to_u32(const unsigned char *addr)
 	return (addr[4] << 8) | addr[5];
 }
 
-static int yt921x_reg_read(struct yt921x_priv *priv, u32 reg, u32 *valp)
-{
-	WARN_ON(!mutex_is_locked(&priv->reg_lock));
-
-	return priv->reg_ops->read(priv->reg_ctx, reg, valp);
-}
-
-static int yt921x_reg_write(struct yt921x_priv *priv, u32 reg, u32 val)
-{
-	WARN_ON(!mutex_is_locked(&priv->reg_lock));
-
-	return priv->reg_ops->write(priv->reg_ctx, reg, val);
-}
-
-static int
-yt921x_reg_wait(struct yt921x_priv *priv, u32 reg, u32 mask, u32 *valp)
-{
-	u32 val;
-	int res;
-	int ret;
-
-	ret = read_poll_timeout(yt921x_reg_read, res,
-				res || (val & mask) == *valp,
-				YT921X_POLL_SLEEP_US, YT921X_POLL_TIMEOUT_US,
-				false, priv, reg, &val);
-	if (ret)
-		return ret;
-	if (res)
-		return res;
-
-	*valp = val;
-	return 0;
-}
-
-static int
-yt921x_reg_update_bits(struct yt921x_priv *priv, u32 reg, u32 mask, u32 val)
-{
-	int res;
-	u32 v;
-	u32 u;
-
-	res = yt921x_reg_read(priv, reg, &v);
-	if (res)
-		return res;
-
-	u = v;
-	u &= ~mask;
-	u |= val;
-	if (u == v)
-		return 0;
-
-	return yt921x_reg_write(priv, reg, u);
-}
-
-static int yt921x_reg_set_bits(struct yt921x_priv *priv, u32 reg, u32 mask)
-{
-	return yt921x_reg_update_bits(priv, reg, 0, mask);
-}
-
-static int yt921x_reg_clear_bits(struct yt921x_priv *priv, u32 reg, u32 mask)
-{
-	return yt921x_reg_update_bits(priv, reg, mask, 0);
-}
-
-static int
-yt921x_reg_toggle_bits(struct yt921x_priv *priv, u32 reg, u32 mask, bool set)
-{
-	return yt921x_reg_update_bits(priv, reg, mask, !set ? 0 : mask);
-}
-
-/* Some multi-word registers, like VLANn_CTRL, should be treated as a single
- * long register. More specifically, writes to parts of its words won't become
- * visible, until the last word is written.
- *
- * Here we require full read and write operations over these registers to
- * eliminate potential issues, although partial reads/writes are also possible.
- */
-
-static void update_ctrls_unaligned(u32 *lo, u32 *hi, u64 mask, u64 val)
-{
-	*lo &= ~lower_32_bits(mask);
-	*hi &= ~upper_32_bits(mask);
-	*lo |= lower_32_bits(val);
-	*hi |= upper_32_bits(val);
-}
-
-static int
-yt921x_regs_read(struct yt921x_priv *priv, u32 reg, u32 *vals,
-		 unsigned int num_regs)
-{
-	int res;
-
-	for (unsigned int i = 0; i < num_regs; i++) {
-		res = yt921x_reg_read(priv, reg + 4 * i, &vals[i]);
-		if (res)
-			return res;
-	}
-
-	return 0;
-}
-
-static int
-yt921x_regs_write(struct yt921x_priv *priv, u32 reg, const u32 *vals,
-		  unsigned int num_regs)
-{
-	int res;
-
-	for (unsigned int i = 0; i < num_regs; i++) {
-		res = yt921x_reg_write(priv, reg + 4 * i, vals[i]);
-		if (res)
-			return res;
-	}
-
-	return 0;
-}
-
-static int
-yt921x_regs_update_bits(struct yt921x_priv *priv, u32 reg, const u32 *masks,
-			const u32 *vals, unsigned int num_regs)
-{
-	bool changed = false;
-	u32 vs[4];
-	int res;
-
-	BUILD_BUG_ON(num_regs > ARRAY_SIZE(vs));
-
-	res = yt921x_regs_read(priv, reg, vs, num_regs);
-	if (res)
-		return res;
-
-	for (unsigned int i = 0; i < num_regs; i++) {
-		u32 u = vs[i];
-
-		u &= ~masks[i];
-		u |= vals[i];
-		if (u != vs[i])
-			changed = true;
-
-		vs[i] = u;
-	}
-
-	if (!changed)
-		return 0;
-
-	return yt921x_regs_write(priv, reg, vs, num_regs);
-}
-
-static int
-yt921x_regs_clear_bits(struct yt921x_priv *priv, u32 reg, const u32 *masks,
-		       unsigned int num_regs)
-{
-	bool changed = false;
-	u32 vs[4];
-	int res;
-
-	BUILD_BUG_ON(num_regs > ARRAY_SIZE(vs));
-
-	res = yt921x_regs_read(priv, reg, vs, num_regs);
-	if (res)
-		return res;
-
-	for (unsigned int i = 0; i < num_regs; i++) {
-		u32 u = vs[i];
-
-		u &= ~masks[i];
-		if (u != vs[i])
-			changed = true;
-
-		vs[i] = u;
-	}
-
-	if (!changed)
-		return 0;
-
-	return yt921x_regs_write(priv, reg, vs, num_regs);
-}
-
-static int
-yt921x_reg64_write(struct yt921x_priv *priv, u32 reg, const u32 *vals)
-{
-	return yt921x_regs_write(priv, reg, vals, 2);
-}
-
-static int
-yt921x_reg64_update_bits(struct yt921x_priv *priv, u32 reg, const u32 *masks,
-			 const u32 *vals)
-{
-	return yt921x_regs_update_bits(priv, reg, masks, vals, 2);
-}
-
-static int
-yt921x_reg64_clear_bits(struct yt921x_priv *priv, u32 reg, const u32 *masks)
-{
-	return yt921x_regs_clear_bits(priv, reg, masks, 2);
-}
-
-static int
-yt921x_reg96_write(struct yt921x_priv *priv, u32 reg, const u32 *vals)
-{
-	return yt921x_regs_write(priv, reg, vals, 3);
-}
-
 static int yt921x_reg_mdio_read(void *context, u32 reg, u32 *valp)
 {
 	struct yt921x_reg_mdio *mdio = context;
diff --git a/drivers/net/dsa/motorcomm/smi.c b/drivers/net/dsa/motorcomm/smi.c
new file mode 100644
index 000000000000..164c25ef494a
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/smi.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2026 David Yang
+ */
+
+#include <linux/iopoll.h>
+
+#include "chip.h"
+#include "smi.h"
+
+#define YT921X_POLL_SLEEP_US	10000
+#define YT921X_POLL_TIMEOUT_US	100000
+
+int yt921x_reg_read(struct yt921x_priv *priv, u32 reg, u32 *valp)
+{
+	WARN_ON(!mutex_is_locked(&priv->reg_lock));
+
+	return priv->reg_ops->read(priv->reg_ctx, reg, valp);
+}
+
+int yt921x_reg_write(struct yt921x_priv *priv, u32 reg, u32 val)
+{
+	WARN_ON(!mutex_is_locked(&priv->reg_lock));
+
+	return priv->reg_ops->write(priv->reg_ctx, reg, val);
+}
+
+int yt921x_reg_wait(struct yt921x_priv *priv, u32 reg, u32 mask, u32 *valp)
+{
+	u32 val;
+	int res;
+	int ret;
+
+	ret = read_poll_timeout(yt921x_reg_read, res,
+				res || (val & mask) == *valp,
+				YT921X_POLL_SLEEP_US, YT921X_POLL_TIMEOUT_US,
+				false, priv, reg, &val);
+	if (ret)
+		return ret;
+	if (res)
+		return res;
+
+	*valp = val;
+	return 0;
+}
+
+int yt921x_reg_update_bits(struct yt921x_priv *priv, u32 reg, u32 mask, u32 val)
+{
+	int res;
+	u32 v;
+	u32 u;
+
+	res = yt921x_reg_read(priv, reg, &v);
+	if (res)
+		return res;
+
+	u = v;
+	u &= ~mask;
+	u |= val;
+	if (u == v)
+		return 0;
+
+	return yt921x_reg_write(priv, reg, u);
+}
+
+int
+yt921x_regs_read(struct yt921x_priv *priv, u32 reg, u32 *vals,
+		 unsigned int num_regs)
+{
+	int res;
+
+	for (unsigned int i = 0; i < num_regs; i++) {
+		res = yt921x_reg_read(priv, reg + 4 * i, &vals[i]);
+		if (res)
+			return res;
+	}
+
+	return 0;
+}
+
+int
+yt921x_regs_write(struct yt921x_priv *priv, u32 reg, const u32 *vals,
+		  unsigned int num_regs)
+{
+	int res;
+
+	for (unsigned int i = 0; i < num_regs; i++) {
+		res = yt921x_reg_write(priv, reg + 4 * i, vals[i]);
+		if (res)
+			return res;
+	}
+
+	return 0;
+}
+
+int
+yt921x_regs_update_bits(struct yt921x_priv *priv, u32 reg, const u32 *masks,
+			const u32 *vals, unsigned int num_regs)
+{
+	bool changed = false;
+	u32 vs[4];
+	int res;
+
+	if (WARN_ON_ONCE(num_regs > ARRAY_SIZE(vs)))
+		return -EINVAL;
+
+	res = yt921x_regs_read(priv, reg, vs, num_regs);
+	if (res)
+		return res;
+
+	for (unsigned int i = 0; i < num_regs; i++) {
+		u32 u = vs[i];
+
+		u &= ~masks[i];
+		u |= vals[i];
+		if (u != vs[i])
+			changed = true;
+
+		vs[i] = u;
+	}
+
+	if (!changed)
+		return 0;
+
+	return yt921x_regs_write(priv, reg, vs, num_regs);
+}
+
+int
+yt921x_regs_clear_bits(struct yt921x_priv *priv, u32 reg, const u32 *masks,
+		       unsigned int num_regs)
+{
+	bool changed = false;
+	u32 vs[4];
+	int res;
+
+	if (WARN_ON_ONCE(num_regs > ARRAY_SIZE(vs)))
+		return -EINVAL;
+
+	res = yt921x_regs_read(priv, reg, vs, num_regs);
+	if (res)
+		return res;
+
+	for (unsigned int i = 0; i < num_regs; i++) {
+		u32 u = vs[i];
+
+		u &= ~masks[i];
+		if (u != vs[i])
+			changed = true;
+
+		vs[i] = u;
+	}
+
+	if (!changed)
+		return 0;
+
+	return yt921x_regs_write(priv, reg, vs, num_regs);
+}
diff --git a/drivers/net/dsa/motorcomm/smi.h b/drivers/net/dsa/motorcomm/smi.h
new file mode 100644
index 000000000000..2995e91f3b3d
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/smi.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2026 David Yang
+ */
+
+#ifndef _YT_SMI_H
+#define _YT_SMI_H
+
+#include <linux/types.h>
+#include <linux/wordpart.h>
+
+struct yt921x_priv;
+
+int yt921x_reg_read(struct yt921x_priv *priv, u32 reg, u32 *valp);
+int yt921x_reg_write(struct yt921x_priv *priv, u32 reg, u32 val);
+int yt921x_reg_wait(struct yt921x_priv *priv, u32 reg, u32 mask, u32 *valp);
+int yt921x_reg_update_bits(struct yt921x_priv *priv, u32 reg, u32 mask,
+			   u32 val);
+
+static inline int
+yt921x_reg_set_bits(struct yt921x_priv *priv, u32 reg, u32 mask)
+{
+	return yt921x_reg_update_bits(priv, reg, 0, mask);
+}
+
+static inline int
+yt921x_reg_clear_bits(struct yt921x_priv *priv, u32 reg, u32 mask)
+{
+	return yt921x_reg_update_bits(priv, reg, mask, 0);
+}
+
+static inline int
+yt921x_reg_toggle_bits(struct yt921x_priv *priv, u32 reg, u32 mask, bool set)
+{
+	return yt921x_reg_update_bits(priv, reg, mask, !set ? 0 : mask);
+}
+
+/* Some multi-word registers, like VLANn_CTRL, should be treated as a single
+ * long register. More specifically, writes to parts of its words won't become
+ * visible, until the last word is written.
+ *
+ * Here we require full read and write operations over these registers to
+ * eliminate potential issues, although partial reads/writes are also possible.
+ */
+
+static inline void update_ctrls_unaligned(u32 *lo, u32 *hi, u64 mask, u64 val)
+{
+	*lo &= ~lower_32_bits(mask);
+	*hi &= ~upper_32_bits(mask);
+	*lo |= lower_32_bits(val);
+	*hi |= upper_32_bits(val);
+}
+
+/* yt921x_regs_*() are exported for linkage only. Do not use them directly. Use
+ * yt921x_reg64_*() or yt921x_reg96_*() instead.
+ */
+
+int yt921x_regs_read(struct yt921x_priv *priv, u32 reg, u32 *vals,
+		     unsigned int num_regs);
+int yt921x_regs_write(struct yt921x_priv *priv, u32 reg, const u32 *vals,
+		      unsigned int num_regs);
+int yt921x_regs_update_bits(struct yt921x_priv *priv, u32 reg, const u32 *masks,
+			    const u32 *vals, unsigned int num_regs);
+int yt921x_regs_clear_bits(struct yt921x_priv *priv, u32 reg, const u32 *masks,
+			   unsigned int num_regs);
+
+static inline int
+yt921x_reg64_write(struct yt921x_priv *priv, u32 reg, const u32 *vals)
+{
+	return yt921x_regs_write(priv, reg, vals, 2);
+}
+
+static inline int
+yt921x_reg64_update_bits(struct yt921x_priv *priv, u32 reg, const u32 *masks,
+			 const u32 *vals)
+{
+	return yt921x_regs_update_bits(priv, reg, masks, vals, 2);
+}
+
+static inline int
+yt921x_reg64_clear_bits(struct yt921x_priv *priv, u32 reg, const u32 *masks)
+{
+	return yt921x_regs_clear_bits(priv, reg, masks, 2);
+}
+
+static inline int
+yt921x_reg96_write(struct yt921x_priv *priv, u32 reg, const u32 *vals)
+{
+	return yt921x_regs_write(priv, reg, vals, 3);
+}
+
+#endif
-- 
2.53.0

[PATCH net-next v10 3/4] net: dsa: motorcomm: Add LED support

[David Yang]

Each port has at most 3 LEDs connected and can be declared using the
standard LEDs structure.

Currently, only parallel mode and strict 1:1 mapping (i.e. the HW
default) are supported.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/dsa/motorcomm/Kconfig  |   9 +
 drivers/net/dsa/motorcomm/Makefile |   1 +
 drivers/net/dsa/motorcomm/chip.c   |  13 +-
 drivers/net/dsa/motorcomm/chip.h   |  12 +
 drivers/net/dsa/motorcomm/leds.c   | 654 +++++++++++++++++++++++++++++
 drivers/net/dsa/motorcomm/leds.h   | 121 ++++++
 6 files changed, 808 insertions(+), 2 deletions(-)
 create mode 100644 drivers/net/dsa/motorcomm/leds.c
 create mode 100644 drivers/net/dsa/motorcomm/leds.h

diff --git a/drivers/net/dsa/motorcomm/Kconfig b/drivers/net/dsa/motorcomm/Kconfig
index 1fddd386f866..3438e0b14361 100644
--- a/drivers/net/dsa/motorcomm/Kconfig
+++ b/drivers/net/dsa/motorcomm/Kconfig
@@ -6,3 +6,12 @@ config NET_DSA_YT921X
 	help
 	  This enables support for the Motorcomm YT9215 ethernet switch
 	  chip.
+
+config NET_DSA_YT921X_LEDS
+	bool "LED support for Motorcomm YT9215"
+	default y
+	depends on NET_DSA_YT921X
+	depends on LEDS_CLASS=y || LEDS_CLASS=NET_DSA_YT921X
+	help
+	  This enables support for controlling the LEDs attached to the
+	  Motorcomm YT9215 switch chips.
diff --git a/drivers/net/dsa/motorcomm/Makefile b/drivers/net/dsa/motorcomm/Makefile
index 6cea5313a444..5a63db0029ff 100644
--- a/drivers/net/dsa/motorcomm/Makefile
+++ b/drivers/net/dsa/motorcomm/Makefile
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: ISC
 obj-$(CONFIG_NET_DSA_YT921X) += yt921x.o
 yt921x-objs := chip.o
+yt921x-$(CONFIG_NET_DSA_YT921X_LEDS) += leds.o
 yt921x-objs += smi.o
diff --git a/drivers/net/dsa/motorcomm/chip.c b/drivers/net/dsa/motorcomm/chip.c
index 6dee25b6754a..553efacd4f5e 100644
--- a/drivers/net/dsa/motorcomm/chip.c
+++ b/drivers/net/dsa/motorcomm/chip.c
@@ -26,6 +26,7 @@
 #include <net/pkt_cls.h>
 
 #include "chip.h"
+#include "leds.h"
 #include "smi.h"
 
 struct yt921x_mib_desc {
@@ -151,8 +152,6 @@ static const struct yt921x_info yt921x_infos[] = {
 	{}
 };
 
-#define YT921X_NAME	"yt921x"
-
 #define YT921X_VID_UNWARE	4095
 
 /* The interval should be small enough to avoid overflow of 32bit MIBs.
@@ -4581,6 +4580,12 @@ static int yt921x_dsa_setup(struct dsa_switch *ds)
 	if (res)
 		return res;
 
+#if IS_ENABLED(CONFIG_NET_DSA_YT921X_LEDS)
+	res = yt921x_leds_setup(priv);
+	if (res)
+		dev_warn(dev, "Failed to setup LEDs: %d\n", res);
+#endif
+
 	return 0;
 }
 
@@ -4681,6 +4686,10 @@ static void yt921x_mdio_remove(struct mdio_device *mdiodev)
 	if (!priv)
 		return;
 
+#if IS_ENABLED(CONFIG_NET_DSA_YT921X_LEDS)
+	yt921x_leds_remove(priv);
+#endif
+
 	for (size_t i = ARRAY_SIZE(priv->ports); i-- > 0; ) {
 		struct yt921x_port *pp = &priv->ports[i];
 
diff --git a/drivers/net/dsa/motorcomm/chip.h b/drivers/net/dsa/motorcomm/chip.h
index 5f3b99e189c4..e6815cf9cb3c 100644
--- a/drivers/net/dsa/motorcomm/chip.h
+++ b/drivers/net/dsa/motorcomm/chip.h
@@ -850,9 +850,14 @@ enum yt921x_fdb_entry_status {
 #define YT921X_ACL_NUM		(YT921X_ACL_BLK_NUM * YT921X_ACL_ENT_PER_BLK)
 #define YT921X_UDF_NUM		8
 
+#define YT921X_LED_GROUP_NUM	3
+#define YT921X_LED_PORT_NUM	10
+
 /* 8 internal + 2 external + 1 mcu */
 #define YT921X_PORT_NUM			11
 
+#define YT921X_NAME	"yt921x"
+
 #define yt921x_port_is_internal(port) ((port) < 8)
 #define yt921x_port_is_external(port) ((port) == 8 || (port) == 9)
 
@@ -938,6 +943,13 @@ struct yt921x_port {
 	struct yt921x_mib mib;
 	u64 rx_frames;
 	u64 tx_frames;
+
+#if IS_ENABLED(CONFIG_NET_DSA_YT921X_LEDS)
+	unsigned char led_duty;
+	unsigned short led_cycle;
+
+	struct yt921x_led *leds[YT921X_LED_GROUP_NUM];
+#endif
 };
 
 struct yt921x_reg_ops {
diff --git a/drivers/net/dsa/motorcomm/leds.c b/drivers/net/dsa/motorcomm/leds.c
new file mode 100644
index 000000000000..e7ef0ef80a26
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/leds.c
@@ -0,0 +1,654 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2026 David Yang
+ */
+
+#include <linux/uleds.h>
+
+#include "chip.h"
+#include "leds.h"
+#include "smi.h"
+
+#define to_yt921x_led(led_cdev) \
+	container_of_const((led_cdev), struct yt921x_led, cdev)
+#define to_yt921x_port(led) ((led)->port)
+#define to_yt921x_priv(pp) \
+	container_of_const((pp), struct yt921x_priv, ports[(pp)->index])
+#define to_device(priv) ((priv)->ds.dev)
+
+static u32 yt921x_led_regaddr(struct yt921x_priv *priv, int port, int group)
+{
+	switch (group) {
+	case 0:
+	default:
+		return YT921X_LED0_PORTn(port);
+	case 1:
+		return YT921X_LED1_PORTn(port);
+	case 2:
+		return YT921X_LED2_PORTn(port);
+	}
+}
+
+static int
+yt921x_led_force_get(struct yt921x_priv *priv, int port, int group, bool *onp)
+{
+	u32 val;
+	int res;
+
+	res = yt921x_reg_read(priv, YT921X_LED2_PORTn(port), &val);
+	if (res)
+		return res;
+
+	*onp = (val & YT921X_LED2_PORT_FORCEn_M(group)) ==
+	       YT921X_LED2_PORT_FORCEn_ON(group);
+	return 0;
+}
+
+static int
+yt921x_led_force_set(struct yt921x_priv *priv, int port, int group, bool on)
+{
+	struct yt921x_port *pp = &priv->ports[port];
+	struct yt921x_led *led = pp->leds[group];
+	u32 ctrl;
+	u32 mask;
+
+	led->use_cycle = false;
+	led->use_duty = false;
+
+	mask = YT921X_LED2_PORT_FORCEn_M(group);
+	ctrl = on ? YT921X_LED2_PORT_FORCEn_ON(group) :
+	       YT921X_LED2_PORT_FORCEn_OFF(group);
+	return yt921x_reg_update_bits(priv, YT921X_LED2_PORTn(port), mask,
+				      ctrl);
+}
+
+static int
+yt921x_led_blink_select(const struct yt921x_priv *priv, unsigned long on,
+			unsigned long off, unsigned short *cyclep,
+			unsigned char *dutyp)
+{
+	static const unsigned char dutys[] = {
+		YT921X_LED_DUTY(1, 6),
+		YT921X_LED_DUTY(1, 4),
+		YT921X_LED_DUTY(1, 3),
+		YT921X_LED_DUTY(1, 2),
+	};
+	unsigned int cycle_upper;
+	unsigned int cycle_req;
+	unsigned int duty_req;
+	unsigned int cycle;
+	unsigned int duty;
+
+	cycle = YT921X_LED_BLINK_MAX;
+	cycle_upper = cycle * 11585 / 8192 + 1;  /* M_SQRT2 * cycle */
+	if (check_add_overflow(on, off, &cycle_req) || cycle_req >= cycle_upper)
+		return -EOPNOTSUPP;
+
+	for (; cycle > YT921X_LED_BLINK_MIN; cycle_upper >>= 1, cycle >>= 1)
+		if (cycle_req >= cycle_upper >> 1)
+			break;
+	*cyclep = cycle;
+
+	duty_req = DIV_ROUND_CLOSEST(YT921X_LED_DUTY_DENOM *
+				     (on > off ? off : on), cycle_req);
+	for (unsigned int i = ARRAY_SIZE(dutys) - 1;; i--)
+		if (i == 0 || duty_req >= (dutys[i - 1] + dutys[i]) / 2) {
+			duty = dutys[i];
+			break;
+		}
+	if (on > off)
+		duty = YT921X_LED_DUTY_DENOM - duty;
+	*dutyp = duty;
+
+	return 0;
+}
+
+static int
+yt921x_led_blink_set(struct yt921x_priv *priv, int port, int group,
+		     unsigned long *onp, unsigned long *offp)
+{
+	struct yt921x_port *pp = &priv->ports[port];
+	struct yt921x_led *led = pp->leds[group];
+	unsigned short cycle;
+	unsigned char duty;
+	bool use_cycle;
+	u32 ctrl;
+	u32 mask;
+	u32 val;
+	int res;
+
+	if (!*onp && !*offp) {
+		cycle = YT921X_LED_BLINK_DEF;
+		duty = YT921X_LED_DUTY(1, 2);
+		for (unsigned int i = 0; i < YT921X_LED_GROUP_NUM; i++)
+			if (i != group && pp->leds[i] &&
+			    pp->leds[i]->use_duty) {
+				duty = pp->led_duty;
+				break;
+			}
+
+		use_cycle = false;
+	} else {
+		bool change_cycle;
+		bool change_duty;
+
+		res = yt921x_led_blink_select(priv, *onp, *offp, &cycle, &duty);
+		if (res)
+			return res;
+
+		use_cycle = cycle < YT921X_LED_BLINK_DEF;
+		change_cycle = use_cycle && cycle != pp->led_cycle;
+		change_duty = duty != pp->led_duty;
+		if (change_cycle || change_duty)
+			for (unsigned int i = 0; i < YT921X_LED_GROUP_NUM;
+			     i++) {
+				if (i == group || !pp->leds[i])
+					continue;
+				if ((change_cycle && pp->leds[i]->use_cycle) ||
+				    (change_duty && pp->leds[i]->use_duty))
+					return -EOPNOTSUPP;
+			}
+	}
+
+	/* The chip seems to jam a while if changing duty directly */
+	res = yt921x_reg_read(priv, YT921X_LED2_PORTn(port), &val);
+	if (res)
+		return res;
+
+	ctrl = val & ~YT921X_LED2_PORT_FORCEn_M(group);
+	ctrl |= YT921X_LED2_PORT_FORCEn_DONTCARE(group);
+	if (val != ctrl) {
+		res = yt921x_reg_write(priv, YT921X_LED2_PORTn(port), ctrl);
+		if (res)
+			return res;
+	}
+
+	mask = YT921X_LED1_PORT_BLINK_DUTY_M | YT921X_LED1_PORT_BLINK_DUTY_COMP;
+	switch (duty >= YT921X_LED_DUTY(1, 2) ? duty :
+		YT921X_LED_DUTY_DENOM - duty) {
+	default:
+		duty = YT921X_LED_DUTY(1, 2);
+		fallthrough;
+	case YT921X_LED_DUTY(1, 2):
+		ctrl = YT921X_LED1_PORT_BLINK_DUTY_1_2;
+		break;
+	case YT921X_LED_DUTY(2, 3):
+		ctrl = YT921X_LED1_PORT_BLINK_DUTY_2_3;
+		break;
+	case YT921X_LED_DUTY(3, 4):
+		ctrl = YT921X_LED1_PORT_BLINK_DUTY_3_4;
+		break;
+	case YT921X_LED_DUTY(5, 6):
+		ctrl = YT921X_LED1_PORT_BLINK_DUTY_5_6;
+		break;
+	}
+	if (duty < YT921X_LED_DUTY(1, 2))
+		ctrl |= YT921X_LED1_PORT_BLINK_DUTY_COMP;
+	if (use_cycle) {
+		mask |= YT921X_LED1_PORT_OTHER_BLINK_M;
+		ctrl |= YT921X_LED1_PORT_OTHER_BLINK(9 - __fls(cycle));
+	}
+	res = yt921x_reg_update_bits(priv, YT921X_LED1_PORTn(port), mask, ctrl);
+	if (res)
+		return res;
+
+	ctrl = val & ~(YT921X_LED2_PORT_FORCEn_M(group) |
+		       YT921X_LED2_PORT_FORCE_BLINKn_M(group));
+	ctrl |= YT921X_LED2_PORT_FORCEn_BLINK(group);
+	if (use_cycle)
+		ctrl |= YT921X_LED2_PORT_FORCE_BLINKn_OTHER(group);
+	else
+		ctrl |= YT921X_LED2_PORT_FORCE_BLINKn(group, __fls(cycle) - 9);
+	res = yt921x_reg_write(priv, YT921X_LED2_PORTn(port), ctrl);
+	if (res)
+		return res;
+
+	led->use_cycle = use_cycle;
+	if (use_cycle)
+		pp->led_cycle = cycle;
+	led->use_duty = true;
+	pp->led_duty = duty;
+
+	*onp = DIV_ROUND_CLOSEST(duty * cycle, YT921X_LED_DUTY_DENOM);
+	*offp = cycle - *onp;
+	return 0;
+}
+
+struct yt921x_led_trigger_map {
+	unsigned long flags;
+	u32 mask;
+};
+
+static const struct yt921x_led_trigger_map yt921x_led_trigger_maps[] = {
+	{BIT(TRIGGER_NETDEV_LINK),
+	 YT921X_LEDx_PORT_ACT_DUPLEX_HALF | YT921X_LEDx_PORT_ACT_DUPLEX_FULL},
+	{BIT(TRIGGER_NETDEV_LINK_10), YT921X_LEDx_PORT_ACT_10M},
+	{BIT(TRIGGER_NETDEV_LINK_100), YT921X_LEDx_PORT_ACT_100M},
+	{BIT(TRIGGER_NETDEV_LINK_1000), YT921X_LEDx_PORT_ACT_1000M},
+	{BIT(TRIGGER_NETDEV_HALF_DUPLEX), YT921X_LEDx_PORT_ACT_DUPLEX_HALF},
+	{BIT(TRIGGER_NETDEV_FULL_DUPLEX), YT921X_LEDx_PORT_ACT_DUPLEX_FULL},
+	{BIT(TRIGGER_NETDEV_TX), YT921X_LEDx_PORT_ACT_TX_BLINK},
+	{BIT(TRIGGER_NETDEV_RX), YT921X_LEDx_PORT_ACT_RX_BLINK},
+	{BIT(TRIGGER_NETDEV_TX_ERR) | BIT(TRIGGER_NETDEV_RX_ERR),
+	 YT921X_LEDx_PORT_ACT_COLLISION_BLINK},
+};
+
+static bool
+yt921x_led_trigger_is_supported(const struct yt921x_priv *priv, int port,
+				int group, unsigned long flags)
+{
+	if (!flags)
+		return true;
+
+	for (unsigned int i = 0; i < ARRAY_SIZE(yt921x_led_trigger_maps); i++) {
+		const struct yt921x_led_trigger_map *map = &yt921x_led_trigger_maps[i];
+
+		if ((flags & map->flags) == map->flags) {
+			flags &= ~map->flags;
+			if (!flags)
+				return true;
+		}
+	}
+
+	return false;
+}
+
+static int
+yt921x_led_trigger_get(struct yt921x_priv *priv, int port, int group,
+		       unsigned long *flagsp)
+{
+	u32 addr;
+	u32 val;
+	int res;
+
+	res = yt921x_reg_read(priv, YT921X_LED2_PORTn(port), &val);
+	if (res)
+		return res;
+
+	if ((val & YT921X_LED2_PORT_FORCEn_M(group)) !=
+	    YT921X_LED2_PORT_FORCEn_DONTCARE(group)) {
+		*flagsp = 0;
+		return 0;
+	}
+
+	if (group != 2) {
+		addr = yt921x_led_regaddr(priv, port, group);
+		res = yt921x_reg_read(priv, addr, &val);
+		if (res)
+			return res;
+	}
+
+	*flagsp = 0;
+	for (unsigned int i = 0; i < ARRAY_SIZE(yt921x_led_trigger_maps); i++) {
+		const struct yt921x_led_trigger_map *map = &yt921x_led_trigger_maps[i];
+
+		if ((val & map->mask) == map->mask)
+			*flagsp |= map->flags;
+	}
+
+	return 0;
+}
+
+static int
+yt921x_led_trigger_set(struct yt921x_priv *priv, int port, int group,
+		       unsigned long flags)
+{
+	struct yt921x_port *pp = &priv->ports[port];
+	struct yt921x_led *led = pp->leds[group];
+	u32 addr;
+	u32 ctrl;
+	u32 mask;
+	int res;
+
+	ctrl = 0;
+	for (unsigned int i = 0; i < ARRAY_SIZE(yt921x_led_trigger_maps); i++) {
+		const struct yt921x_led_trigger_map *map = &yt921x_led_trigger_maps[i];
+
+		if ((flags & map->flags) == map->flags) {
+			flags &= ~map->flags;
+			ctrl |= map->mask;
+			if (!flags)
+				break;
+		}
+	}
+	if (flags)
+		return -EOPNOTSUPP;
+
+	led->use_cycle = false;
+	led->use_duty = false;
+
+	mask = !group ? YT921X_LED0_PORT_ACT_M : YT921X_LEDx_PORT_ACT_M;
+	if (group == 2) {
+		mask |= YT921X_LED2_PORT_FORCEn_M(group);
+		ctrl |= YT921X_LED2_PORT_FORCEn_DONTCARE(group);
+	}
+	addr = yt921x_led_regaddr(priv, port, group);
+	res = yt921x_reg_update_bits(priv, addr, mask, ctrl);
+	if (res)
+		return res;
+
+	if (group != 2) {
+		mask = YT921X_LED2_PORT_FORCEn_M(group);
+		ctrl = YT921X_LED2_PORT_FORCEn_DONTCARE(group);
+		res = yt921x_reg_update_bits(priv, YT921X_LED2_PORTn(port),
+					     mask, ctrl);
+		if (res)
+			return res;
+	}
+
+	return 0;
+}
+
+static int
+yt921x_cled_brightness_set_blocking(struct led_classdev *led_cdev,
+				    enum led_brightness brightness)
+{
+	struct yt921x_led *led = to_yt921x_led(led_cdev);
+	struct yt921x_port *pp = to_yt921x_port(led);
+	struct yt921x_priv *priv = to_yt921x_priv(pp);
+	int res;
+
+	mutex_lock(&priv->reg_lock);
+	res = yt921x_led_force_set(priv, pp->index, led->group, brightness);
+	mutex_unlock(&priv->reg_lock);
+
+	return res;
+}
+
+static int
+yt921x_cled_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on,
+		      unsigned long *delay_off)
+{
+	struct yt921x_led *led = to_yt921x_led(led_cdev);
+	struct yt921x_port *pp = to_yt921x_port(led);
+	struct yt921x_priv *priv = to_yt921x_priv(pp);
+	int res;
+
+	mutex_lock(&priv->reg_lock);
+	res = yt921x_led_blink_set(priv, pp->index, led->group, delay_on,
+				   delay_off);
+	mutex_unlock(&priv->reg_lock);
+
+	return res;
+}
+
+static struct device * __maybe_unused
+yt921x_cled_hw_control_get_device(struct led_classdev *led_cdev)
+{
+	struct yt921x_led *led = to_yt921x_led(led_cdev);
+	struct yt921x_port *pp = to_yt921x_port(led);
+	struct yt921x_priv *priv = to_yt921x_priv(pp);
+	struct dsa_port *dp;
+
+	dp = dsa_to_port(&priv->ds, pp->index);
+	if (!dp)
+		return NULL;
+
+	if (dsa_port_is_user(dp))
+		return &dp->user->dev;
+	if (dsa_port_is_cpu(dp))
+		return &dp->conduit->dev;
+
+	return NULL;
+}
+
+static int __maybe_unused
+yt921x_cled_hw_control_is_supported(struct led_classdev *led_cdev,
+				    unsigned long flags)
+{
+	struct yt921x_led *led = to_yt921x_led(led_cdev);
+	struct yt921x_port *pp = to_yt921x_port(led);
+	struct yt921x_priv *priv = to_yt921x_priv(pp);
+
+	if (yt921x_led_trigger_is_supported(priv, pp->index, led->group, flags))
+		return 0;
+	return -EOPNOTSUPP;
+}
+
+static int __maybe_unused
+yt921x_cled_hw_control_get(struct led_classdev *led_cdev, unsigned long *flagsp)
+{
+	struct yt921x_led *led = to_yt921x_led(led_cdev);
+	struct yt921x_port *pp = to_yt921x_port(led);
+	struct yt921x_priv *priv = to_yt921x_priv(pp);
+	int res;
+
+	mutex_lock(&priv->reg_lock);
+	res = yt921x_led_trigger_get(priv, pp->index, led->group, flagsp);
+	mutex_unlock(&priv->reg_lock);
+
+	return res;
+}
+
+static int __maybe_unused
+yt921x_cled_hw_control_set(struct led_classdev *led_cdev, unsigned long flags)
+{
+	struct yt921x_led *led = to_yt921x_led(led_cdev);
+	struct yt921x_port *pp = to_yt921x_port(led);
+	struct yt921x_priv *priv = to_yt921x_priv(pp);
+	int res;
+
+	mutex_lock(&priv->reg_lock);
+	res = yt921x_led_trigger_set(priv, pp->index, led->group, flags);
+	mutex_unlock(&priv->reg_lock);
+
+	return res;
+}
+
+static int
+yt921x_led_setup(struct yt921x_priv *priv, int port,
+		 struct fwnode_handle *fwnode)
+{
+	struct yt921x_port *pp = &priv->ports[port];
+	struct device *dev = to_device(priv);
+	struct led_init_data init_data;
+	struct led_classdev *led_cdev;
+	char name[LED_MAX_NAME_SIZE];
+	enum led_default_state state;
+	struct yt921x_led *led;
+	bool force_high;
+	bool force_low;
+	u32 group;
+	u32 mask;
+	u32 ctrl;
+	u32 val;
+	bool on;
+	int res;
+	int ret;
+
+	res = fwnode_property_read_u32(fwnode, "reg", &group);
+	if (res)
+		return res;
+	if (group >= YT921X_LED_GROUP_NUM) {
+		dev_err(dev, "Invalid LED reg %u for port %d\n", group, port);
+		return -EINVAL;
+	}
+	if (pp->leds[group])
+		return -EEXIST;
+
+	force_high = fwnode_property_read_bool(fwnode, "active-high");
+	force_low = fwnode_property_read_bool(fwnode, "active-low");
+	if (force_high && force_low) {
+		dev_err(dev, "Duplicate polarities for LED %02d:%02u\n",
+			port, group);
+		return -EINVAL;
+	}
+
+	led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+	led->port = pp;
+	led->group = group;
+
+	state = led_init_default_state_get(fwnode);
+
+	mutex_lock(&priv->reg_lock);
+
+	/* Inversion is internal - force on will give low logic.
+	 * In the rest of the file, treat LEDs as if active-low.
+	 */
+	if (force_high || force_low) {
+		res = yt921x_reg_read(priv, YT921X_LED_PAR_INV, &val);
+		if (res)
+			goto unlock;
+
+		mask = YT921X_LED_PAR_INV_INVnm(group, port);
+		ctrl = force_high ? val | mask : val & ~mask;
+		res = yt921x_reg_write(priv, YT921X_LED_PAR_INV, ctrl);
+		if (res)
+			goto unlock;
+	}
+
+	pp->leds[group] = led;
+
+	switch (state) {
+	case LEDS_DEFSTATE_OFF:
+	case LEDS_DEFSTATE_ON:
+	default:
+		on = state == LEDS_DEFSTATE_ON;
+		res = yt921x_led_force_set(priv, port, group, on);
+		break;
+	case LEDS_DEFSTATE_KEEP:
+		res = yt921x_led_force_get(priv, port, group, &on);
+		break;
+	}
+
+unlock:
+	mutex_unlock(&priv->reg_lock);
+	if (res)
+		goto err;
+
+	led_cdev = &led->cdev;
+	led_cdev->brightness = on;
+	led_cdev->max_brightness = 1;
+	led_cdev->flags = LED_RETAIN_AT_SHUTDOWN;
+	led_cdev->brightness_set_blocking = yt921x_cled_brightness_set_blocking;
+	led_cdev->blink_set = yt921x_cled_blink_set;
+#ifdef CONFIG_LEDS_TRIGGERS
+	led_cdev->hw_control_trigger = "netdev";
+	led_cdev->hw_control_get_device = yt921x_cled_hw_control_get_device;
+	led_cdev->hw_control_is_supported = yt921x_cled_hw_control_is_supported;
+	led_cdev->hw_control_get = yt921x_cled_hw_control_get;
+	led_cdev->hw_control_set = yt921x_cled_hw_control_set;
+#endif
+
+	snprintf(name, sizeof(name), YT921X_NAME "-%u:%02d:%02u",
+		 priv->ds.index, port, group);
+	init_data = (typeof(init_data)){
+		.fwnode = fwnode,
+		.default_label = ":port",
+		.devicename = name,
+		.devname_mandatory = true,
+	};
+	res = devm_led_classdev_register_ext(dev, led_cdev, &init_data);
+	if (res)
+		goto err;
+
+	return 0;
+
+err:
+	ret = res;
+
+	mutex_lock(&priv->reg_lock);
+	if (pp->leds[group]) {
+		if (force_high || force_low) {
+			res = yt921x_reg_write(priv, YT921X_LED_PAR_INV, val);
+			if (res)
+				dev_warn(dev,
+					 "Failed to revoke initialization for LED %02d:%02u\n",
+					 port, group);
+		}
+
+		pp->leds[group] = NULL;
+	}
+	mutex_unlock(&priv->reg_lock);
+
+	devm_kfree(dev, led);
+	return ret;
+}
+
+static void yt921x_leds_remove_port(struct yt921x_priv *priv, int port)
+{
+	struct yt921x_port *pp = &priv->ports[port];
+	struct device *dev = to_device(priv);
+	bool has_leds = false;
+
+	for (int group = 0; group < YT921X_LED_GROUP_NUM; group++) {
+		struct yt921x_led *led = pp->leds[group];
+
+		if (led) {
+			devm_led_classdev_unregister(dev, &led->cdev);
+			has_leds = true;
+		}
+	}
+
+	if (!has_leds)
+		return;
+
+	/* Now no one can access the LED control blocks, free them without
+	 * holding the lock.
+	 */
+	for (int group = 0; group < YT921X_LED_GROUP_NUM; group++) {
+		struct yt921x_led *led = pp->leds[group];
+
+		if (led) {
+			pp->leds[group] = NULL;
+			devm_kfree(dev, led);
+		}
+	}
+}
+
+static int yt921x_leds_setup_port(struct yt921x_priv *priv, int port)
+{
+	struct device *dev = to_device(priv);
+	struct dsa_switch *ds = &priv->ds;
+	struct device_node *leds_np;
+	struct dsa_port *dp;
+
+	dp = dsa_to_port(ds, port);
+	leds_np = of_get_child_by_name(dp->dn, "leds");
+	if (!leds_np)
+		return 0;
+
+	if (port >= YT921X_LED_PORT_NUM) {
+		dev_err(dev, "Cannot configure LEDs for port %d\n", port);
+		of_node_put(leds_np);
+		return -EINVAL;
+	}
+
+	for_each_child_of_node_scoped(leds_np, led_np) {
+		yt921x_led_setup(priv, port, of_fwnode_handle(led_np));
+		/* Allow partial configuration: LEDs are optional */
+	}
+
+	of_node_put(leds_np);
+	return 0;
+}
+
+void yt921x_leds_remove(struct yt921x_priv *priv)
+{
+	for (int port = 0; port < YT921X_LED_PORT_NUM; port++)
+		yt921x_leds_remove_port(priv, port);
+}
+
+int yt921x_leds_setup(struct yt921x_priv *priv)
+{
+	struct dsa_switch *ds = &priv->ds;
+	struct dsa_port *dp;
+
+	/* LEDs are always enabled. There is no way to disable them altogether
+	 * (as far as I know).
+	 */
+
+	dsa_switch_for_each_port(dp, ds) {
+		int port = dp->index;
+
+		if (!dp->dn)
+			continue;
+
+		yt921x_leds_setup_port(priv, port);
+		/* Allow partial configuration: LEDs are optional */
+	}
+
+	return 0;
+}
diff --git a/drivers/net/dsa/motorcomm/leds.h b/drivers/net/dsa/motorcomm/leds.h
new file mode 100644
index 000000000000..3c3642988ac7
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/leds.h
@@ -0,0 +1,121 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2026 David Yang
+ */
+
+#ifndef _YT_LEDS_H
+#define _YT_LEDS_H
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/kconfig.h>
+#include <linux/leds.h>
+
+#define YT921X_LED_CTRL			0xd0000
+#define  YT921X_LED_CTRL_UNK			BIT(21)
+#define  YT921X_LED_CTRL_LOOPDETECT_BLINK_M	GENMASK(20, 19)	/* cycle = 512 * x ms */
+#define   YT921X_LED_CTRL_LOOPDETECT_BLINK(x)		FIELD_PREP(YT921X_LED_CTRL_LOOPDETECT_BLINK_M, (x))
+#define  YT921X_LED_CTRL_PORT_NUM_M		GENMASK(16, 13)
+#define   YT921X_LED_CTRL_PORT_NUM(x)			FIELD_PREP(YT921X_LED_CTRL_PORT_NUM_M, (x))
+#define  YT921X_LED_CTRL_MODE_M			GENMASK(1, 0)
+#define   YT921X_LED_CTRL_MODE(x)			FIELD_PREP(YT921X_LED_CTRL_MODE_M, (x))
+#define   YT921X_LED_CTRL_MODE_PARALLEL			YT921X_LED_CTRL_MODE(0)
+#define   YT921X_LED_CTRL_MODE_SERIAL			YT921X_LED_CTRL_MODE(2)
+#define YT921X_LED0_PORTn(port)		(0xd0004 + 4 * (port))
+#define  YT921X_LED0_PORT_ACT_M			GENMASK(17, 0)
+#define  YT921X_LED0_PORT_ACT_LINK_TRY_DIS	BIT(17)
+#define  YT921X_LED0_PORT_ACT_COLLISION_BLINK_INDI	BIT(16)
+#define YT921X_LED1_PORTn(port)		(0xd0040 + 4 * (port))
+#define  YT921X_LED1_PORT_OTHER_BLINK_M		GENMASK(31, 30)	/* cycle = 512 >> x ms */
+#define   YT921X_LED1_PORT_OTHER_BLINK(x)		FIELD_PREP(YT921X_LED1_PORT_OTHER_BLINK_M, (x))
+#define  YT921X_LED1_PORT_EEE_BLINK_M		GENMASK(29, 28)	/* cycle = 512 >> x ms */
+#define   YT921X_LED1_PORT_EEE_BLINK(x)			FIELD_PREP(YT921X_LED1_PORT_EEE_BLINK_M, (x))
+#define  YT921X_LED1_PORT_BLINK_DUTY_COMP	BIT(27)
+#define  YT921X_LED1_PORT_BLINK_DUTY_M		GENMASK(26, 25)
+#define   YT921X_LED1_PORT_BLINK_DUTY(x)		FIELD_PREP(YT921X_LED1_PORT_BLINK_DUTY_M, (x))
+#define   YT921X_LED1_PORT_BLINK_DUTY_1_2		YT921X_LED1_PORT_BLINK_DUTY(0)
+#define   YT921X_LED1_PORT_BLINK_DUTY_2_3		YT921X_LED1_PORT_BLINK_DUTY(1)
+#define   YT921X_LED1_PORT_BLINK_DUTY_3_4		YT921X_LED1_PORT_BLINK_DUTY(2)
+#define   YT921X_LED1_PORT_BLINK_DUTY_5_6		YT921X_LED1_PORT_BLINK_DUTY(3)
+#define YT921X_LED2_PORTn(port)		(0xd0080 + 4 * (port))
+#define  YT921X_LED2_PORT_FORCEn_M(grp)		GENMASK(4 * (grp) + 19, 4 * (grp) + 18)
+#define   YT921X_LED2_PORT_FORCEn(grp, x)		((x) << (4 * (grp) + 18))
+#define   YT921X_LED2_PORT_FORCEn_DONTCARE(grp)		YT921X_LED2_PORT_FORCEn(grp, 0)
+#define   YT921X_LED2_PORT_FORCEn_BLINK(grp)		YT921X_LED2_PORT_FORCEn(grp, 1)
+#define   YT921X_LED2_PORT_FORCEn_ON(grp)		YT921X_LED2_PORT_FORCEn(grp, 2)
+#define   YT921X_LED2_PORT_FORCEn_OFF(grp)		YT921X_LED2_PORT_FORCEn(grp, 3)
+#define  YT921X_LED2_PORT_FORCE_BLINKn_M(grp)	GENMASK(4 * (grp) + 17, 4 * (grp) + 16)	/* cycle = 512 << x ms */
+#define   YT921X_LED2_PORT_FORCE_BLINKn(grp, x)		((x) << (4 * (grp) + 16))
+#define   YT921X_LED2_PORT_FORCE_BLINKn_OTHER(grp)	YT921X_LED2_PORT_FORCE_BLINKn(grp, 3)
+#define  YT921X_LEDx_PORT_ACT_M			GENMASK(15, 0)
+#define  YT921X_LEDx_PORT_ACT_EEE_BLINK		BIT(15)
+#define  YT921X_LEDx_PORT_ACT_LOOPDETECT_BLINK	BIT(14)
+#define  YT921X_LEDx_PORT_ACT_ACTIVE_BLINK	BIT(13)
+#define  YT921X_LEDx_PORT_ACT_DUPLEX_FULL	BIT(12)
+#define  YT921X_LEDx_PORT_ACT_DUPLEX_HALF	BIT(11)
+#define  YT921X_LEDx_PORT_ACT_TX_BLINK		BIT(10)
+#define  YT921X_LEDx_PORT_ACT_RX_BLINK		BIT(9)
+#define  YT921X_LEDx_PORT_ACT_TX		BIT(8)
+#define  YT921X_LEDx_PORT_ACT_RX		BIT(7)
+#define  YT921X_LEDx_PORT_ACT_1000M		BIT(6)
+#define  YT921X_LEDx_PORT_ACT_100M		BIT(5)
+#define  YT921X_LEDx_PORT_ACT_10M		BIT(4)
+#define  YT921X_LEDx_PORT_ACT_COLLISION_BLINK	BIT(3)
+#define  YT921X_LEDx_PORT_ACT_1000M_BLINK	BIT(2)
+#define  YT921X_LEDx_PORT_ACT_100M_BLINK	BIT(1)
+#define  YT921X_LEDx_PORT_ACT_10M_BLINK		BIT(0)
+#define YT921X_LED_SER_CTRL		0xd0100
+#define  YT921X_LED_SER_CTRL_UNK		GENMASK(25, 24)	/* delay? */
+#define  YT921X_LED_SER_CTRL_ACTIVE_LOW		BIT(4)
+#define  YT921X_LED_SER_CTRL_GRP_NUM_M		GENMASK(1, 0)	/* #grp - 1 */
+#define   YT921X_LED_SER_CTRL_GRP_NUM(x)		FIELD_PREP(YT921X_LED_SER_CTRL_GRP_NUM_M, (x))
+#define YT921X_LED_SER_MAPnm(grp, port)	(0xd0104 + 8 * (2 - (grp)) + 4 * ((port) / 5))
+#define  YT921X_LED_SER_MAP_DSTn_PORT_M(port)	GENMASK(6 * ((port) % 5) + 5, 6 * ((port) % 5) + 2)
+#define   YT921X_LED_SER_MAP_DSTn_PORT(port, x)		((x) << (6 * ((port) % 5) + 2))
+#define  YT921X_LED_SER_MAP_DSTn_LED_M(port)	GENMASK(6 * ((port) % 5) + 1, 6 * ((port) % 5))
+#define   YT921X_LED_SER_MAP_DSTn_LED(port, x)		((x) << (6 * ((port) % 5)))
+#define YT921X_LED_PAR_PORTS		0xd01c4
+#define YT921X_LED_PAR_INV		0xd01c8
+#define  YT921X_LED_PAR_INV_INVnm(grp, port)	BIT(10 * (grp) + (port))
+#define YT921X_LED_PAR_MAPn(port)	(0xd01d0 + 4 * (port))
+#define  YT921X_LED_PAR_MAP_DSTn_PORT_M(grp)	GENMASK(6 * (grp) + 5, 6 * (grp) + 2)
+#define   YT921X_LED_PAR_MAP_DSTn_PORT(grp, x)		((x) << (6 * (grp) + 2))
+#define  YT921X_LED_PAR_MAP_DSTn_LED_M(grp)	GENMASK(6 * (grp) + 1, 6 * (grp))
+#define   YT921X_LED_PAR_MAP_DSTn_LED(grp, x)		((x) << (6 * (grp)))
+
+#define YT921X_LED_BLINK_MIN	64
+#define YT921X_LED_BLINK_DEF	512
+#define YT921X_LED_BLINK_MAX	2048
+
+/* 2 * lcm(2, 3, 4, 6) */
+#define YT921X_LED_DUTY_DENOM		24
+#define YT921X_LED_DUTY(nom, denom)	(YT921X_LED_DUTY_DENOM * (nom) / (denom))
+
+struct yt921x_priv;
+
+struct yt921x_led {
+	struct led_classdev cdev;
+	struct yt921x_port *port;
+	unsigned char group;
+
+	bool use_cycle:1;
+	bool use_duty:1;
+};
+
+#if IS_ENABLED(CONFIG_NET_DSA_YT921X_LEDS)
+
+void yt921x_leds_remove(struct yt921x_priv *priv);
+int yt921x_leds_setup(struct yt921x_priv *priv);
+
+#else
+
+static inline void yt921x_leds_remove(struct yt921x_priv *priv) {}
+
+static inline int yt921x_leds_setup(struct yt921x_priv *priv)
+{
+	return 0;
+}
+
+#endif
+
+#endif
-- 
2.53.0

[PATCH net-next v10 4/4] dt-bindings: net: dsa: yt921x: Add LEDs definition example

[David Yang]

Add LEDs definition example for yt921x to describe how they should be
defined for a correct usage.

Signed-off-by: David Yang <mmyangfl@gmail.com>
---
 .../bindings/net/dsa/motorcomm,yt921x.yaml    | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/dsa/motorcomm,yt921x.yaml b/Documentation/devicetree/bindings/net/dsa/motorcomm,yt921x.yaml
index 33a6552e46fc..93ba5b181205 100644
--- a/Documentation/devicetree/bindings/net/dsa/motorcomm,yt921x.yaml
+++ b/Documentation/devicetree/bindings/net/dsa/motorcomm,yt921x.yaml
@@ -21,6 +21,9 @@ description: |
 
   Any port can be used as the CPU port.
 
+  Each port has at most 3 LEDs connected and can be declared using the standard
+  LEDs structure.
+
 properties:
   compatible:
     const: motorcomm,yt9215
@@ -59,6 +62,7 @@ unevaluatedProperties: false
 examples:
   - |
     #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/leds/common.h>
 
     mdio {
         #address-cells = <1>;
@@ -113,6 +117,25 @@ examples:
                     label = "lan1";
                     phy-mode = "internal";
                     phy-handle = <&sw_phy0>;
+
+                    leds {
+                        #address-cells = <1>;
+                        #size-cells = <0>;
+
+                        led@0 {
+                            reg = <0>;
+                            color = <LED_COLOR_ID_WHITE>;
+                            function = LED_FUNCTION_LAN;
+                            default-state = "keep";
+                        };
+
+                        led@1 {
+                            reg = <1>;
+                            color = <LED_COLOR_ID_AMBER>;
+                            function = LED_FUNCTION_LAN;
+                            default-state = "keep";
+                        };
+                    };
                 };
 
                 ethernet-port@1 {
-- 
2.53.0

Re: [PATCH net-next v10 3/4] net: dsa: motorcomm: Add LED support

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Critical] Unconditional kernel panic during probe due to pointer arithmetic on NULL net_device pointers in yt921x_cled_hw_control_get_device().
--

--- Patch [3]: [PATCH net-next v10 3/4] net: dsa: motorcomm: Add LED support ---
commit 25a5fb03fc03b52bd3ea80525b1fd57bd6de812d
Author: David Yang <mmyangfl@gmail.com>

net: dsa: motorcomm: Add LED support

This commit adds support for controlling the LEDs attached to the
Motorcomm YT9215 switch chips via the standard LEDs subsystem. It
currently supports parallel mode and strict 1:1 mapping.

> diff --git a/drivers/net/dsa/motorcomm/leds.c b/drivers/net/dsa/motorcomm/leds.c
> new file mode 100644
> index 0000000000000..e7ef0ef80a266
> --- /dev/null
> +++ b/drivers/net/dsa/motorcomm/leds.c

[ ... ]

> +static struct device * __maybe_unused
> +yt921x_cled_hw_control_get_device(struct led_classdev *led_cdev)
> +{
> +	struct yt921x_led *led = to_yt921x_led(led_cdev);
> +	struct yt921x_port *pp = to_yt921x_port(led);
> +	struct yt921x_priv *priv = to_yt921x_priv(pp);
> +	struct dsa_port *dp;
> +
> +	dp = dsa_to_port(&priv->ds, pp->index);
> +	if (!dp)
> +		return NULL;
> +
> +	if (dsa_port_is_user(dp))
> +		return &dp->user->dev;
> +	if (dsa_port_is_cpu(dp))
> +		return &dp->conduit->dev;

[Severity: Critical]
Could this cause a kernel panic during probe if dp->user or dp->conduit is
NULL?

When the hw_control_trigger is set to netdev during driver setup, the LED
core immediately activates the netdev trigger, which in turn calls
yt921x_cled_hw_control_get_device().

At this point during probe, the user ports are not fully instantiated yet,
meaning dp->user is NULL. Unconditionally returning &dp->user->dev performs
pointer arithmetic on the NULL pointer, yielding a non-zero invalid pointer
because dev is located at an offset within struct net_device.

The netdev trigger core evaluates this pointer as true and calls to_net_dev()
on it, which subtracts the offset and yields exactly NULL. It then attempts
to dereference the network device name, crashing the kernel.

Does this need an explicit check to verify dp->user and dp->conduit are valid
pointers before accessing their dev members?

> +
> +	return NULL;
> +}

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260816193905.218112-1-mmyangfl@gmail.com?part=3