[PATCH net-next v12 0/5] net: dsa: motorcomm: Add LED support

[PATCH net-next v12 0/5] 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.

v11: https://lore.kernel.org/r/20260831044818.4103477-1-mmyangfl@gmail.com
  - handle one of *delay_on / *delay_off is zero
  - fix error path for yt921x_led_setup()
v10: https://lore.kernel.org/r/20260816193905.218112-1-mmyangfl@gmail.com
  - new patch to fix lock status check
  - LED control block redesigned
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 (5):
  net: dsa: yt921x: Check lock status with lockdep_assert_held_once()
  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}    | 228 +-----
 .../net/dsa/{yt921x.h => motorcomm/chip.h}    |  15 +
 drivers/net/dsa/motorcomm/leds.c              | 666 ++++++++++++++++++
 drivers/net/dsa/motorcomm/leds.h              | 118 ++++
 drivers/net/dsa/motorcomm/smi.c               | 180 +++++
 drivers/net/dsa/motorcomm/smi.h               |  61 ++
 12 files changed, 1108 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 v12 1/5] net: dsa: yt921x: Check lock status with lockdep_assert_held_once()

[David Yang]

mutex_is_locked() was used to check the lock status. While it should not
be triggered unless a bug is introduced, it does not warn on lock being
held by another thread. Fix it with lockdep helpers.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/dsa/yt921x.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c
index 159b16606f6c..44fcdd47ffb5 100644
--- a/drivers/net/dsa/yt921x.c
+++ b/drivers/net/dsa/yt921x.c
@@ -198,14 +198,14 @@ static u32 ethaddr_lo2_to_u32(const unsigned char *addr)
 
 static int yt921x_reg_read(struct yt921x_priv *priv, u32 reg, u32 *valp)
 {
-	WARN_ON(!mutex_is_locked(&priv->reg_lock));
+	lockdep_assert_held_once(&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));
+	lockdep_assert_held_once(&priv->reg_lock);
 
 	return priv->reg_ops->write(priv->reg_ctx, reg, val);
 }
-- 
2.53.0

[PATCH net-next v12 2/5] 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 0b42e898f4d8..4b0254f62277 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18422,7 +18422,7 @@ 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 676fb7dffe14..8d8edcf89f10 100644
--- a/drivers/net/dsa/Kconfig
+++ b/drivers/net/dsa/Kconfig
@@ -82,6 +82,8 @@ 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"
@@ -168,12 +170,4 @@ 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 6ceb78a755d7..df849cd0e640 100644
--- a/drivers/net/dsa/Makefile
+++ b/drivers/net/dsa/Makefile
@@ -15,11 +15,11 @@ 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-$(CONFIG_NET_DSA_YT921X) += yt921x.o
 obj-y				+= b53/
 obj-y				+= hirschmann/
 obj-y				+= lantiq/
 obj-y				+= microchip/
+obj-y				+= motorcomm/
 obj-y				+= mv88e6xxx/
 obj-y				+= mxl862xx/
 obj-y				+= netc/
diff --git a/drivers/net/dsa/motorcomm/Kconfig b/drivers/net/dsa/motorcomm/Kconfig
new file mode 100644
index 000000000000..64ff7d07a91b
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/Kconfig
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NET_DSA_YT921X
+	tristate "Motorcomm YT9215 ethernet switch chip support"
+	select NET_DSA_TAG_YT921X
+	select NET_IEEE8021Q_HELPERS if DCB
+	help
+	  This enables support for the Motorcomm YT9215 ethernet switch
+	  chip.
diff --git a/drivers/net/dsa/motorcomm/Makefile b/drivers/net/dsa/motorcomm/Makefile
new file mode 100644
index 000000000000..bf99feb4c454
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(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 44fcdd47ffb5..019b3a2d5d97 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 v12 3/5] 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    | 180 +++++++++++++++++++++++++
 drivers/net/dsa/motorcomm/smi.h    |  61 +++++++++
 4 files changed, 243 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 bf99feb4c454..9fa24929007c 100644
--- a/drivers/net/dsa/motorcomm/Makefile
+++ b/drivers/net/dsa/motorcomm/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 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 019b3a2d5d97..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)
-{
-	lockdep_assert_held_once(&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)
-{
-	lockdep_assert_held_once(&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..bf3adfd64165
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/smi.c
@@ -0,0 +1,180 @@
+// 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)
+{
+	lockdep_assert_held_once(&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)
+{
+	lockdep_assert_held_once(&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);
+}
+
+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);
+}
+
+int
+yt921x_reg64_write(struct yt921x_priv *priv, u32 reg, const u32 *vals)
+{
+	return yt921x_regs_write(priv, reg, vals, 2);
+}
+
+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);
+}
+
+int
+yt921x_reg64_clear_bits(struct yt921x_priv *priv, u32 reg, const u32 *masks)
+{
+	return yt921x_regs_clear_bits(priv, reg, masks, 2);
+}
+
+int
+yt921x_reg96_write(struct yt921x_priv *priv, u32 reg, const u32 *vals)
+{
+	return yt921x_regs_write(priv, reg, vals, 3);
+}
diff --git a/drivers/net/dsa/motorcomm/smi.h b/drivers/net/dsa/motorcomm/smi.h
new file mode 100644
index 000000000000..212e20f71d80
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/smi.h
@@ -0,0 +1,61 @@
+/* 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);
+}
+
+int yt921x_reg64_write(struct yt921x_priv *priv, u32 reg, const u32 *vals);
+int yt921x_reg64_update_bits(struct yt921x_priv *priv, u32 reg,
+			     const u32 *masks, const u32 *vals);
+int yt921x_reg64_clear_bits(struct yt921x_priv *priv, u32 reg,
+			    const u32 *masks);
+int yt921x_reg96_write(struct yt921x_priv *priv, u32 reg, const u32 *vals);
+
+#endif
-- 
2.53.0

[PATCH net-next v12 4/5] 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   |  19 +-
 drivers/net/dsa/motorcomm/chip.h   |  15 +
 drivers/net/dsa/motorcomm/leds.c   | 666 +++++++++++++++++++++++++++++
 drivers/net/dsa/motorcomm/leds.h   | 118 +++++
 6 files changed, 826 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 64ff7d07a91b..79cdd79a1fd2 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 9fa24929007c..aeb12cb91f93 100644
--- a/drivers/net/dsa/motorcomm/Makefile
+++ b/drivers/net/dsa/motorcomm/Makefile
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 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..d663af010f43 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.
@@ -4225,6 +4224,15 @@ static int yt921x_edata_read(struct yt921x_priv *priv, u8 addr, u8 *valp)
 	return yt921x_edata_read_cont(priv, addr, valp);
 }
 
+static void yt921x_dsa_teardown(struct dsa_switch *ds)
+{
+	struct yt921x_priv *priv = to_yt921x_priv(ds);
+
+#if IS_ENABLED(CONFIG_NET_DSA_YT921X_LEDS)
+	yt921x_leds_remove(priv);
+#endif
+}
+
 static int yt921x_chip_detect(struct yt921x_priv *priv)
 {
 	struct device *dev = to_device(priv);
@@ -4581,6 +4589,12 @@ 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;
 }
 
@@ -4661,6 +4675,7 @@ static const struct dsa_switch_ops yt921x_dsa_switch_ops = {
 	.port_add_dscp_prio	= yt921x_dsa_port_add_dscp_prio,
 #endif
 	/* chip */
+	.teardown		= yt921x_dsa_teardown,
 	.setup			= yt921x_dsa_setup,
 };
 
diff --git a/drivers/net/dsa/motorcomm/chip.h b/drivers/net/dsa/motorcomm/chip.h
index 5f3b99e189c4..83cd454955dd 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 +943,16 @@ 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;
+
+	unsigned char led_duty_mask;
+	unsigned char led_cycle_mask;
+
+	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..77f6eb834d6d
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/leds.c
@@ -0,0 +1,666 @@
+// 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_set(struct yt921x_priv *priv, int port, int group, bool on)
+{
+	struct yt921x_port *pp = &priv->ports[port];
+	u32 ctrl;
+	u32 mask;
+
+	/* No revoking - LED is sacrificed in case of IO error */
+	pp->led_duty_mask &= ~BIT(group);
+	pp->led_cycle_mask &= ~BIT(group);
+
+	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];
+	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 = (pp->led_duty_mask & ~BIT(group)) ? pp->led_duty :
+		       YT921X_LED_DUTY(1, 2);
+
+		use_cycle = false;
+	} else if (!*onp || !*offp) {
+		return yt921x_led_force_set(priv, port, group, *onp);
+	} else {
+		res = yt921x_led_blink_select(priv, *onp, *offp, &cycle, &duty);
+		if (res)
+			return res;
+
+		use_cycle = cycle < YT921X_LED_BLINK_DEF;
+
+		if (use_cycle && cycle != pp->led_cycle &&
+		    (pp->led_cycle_mask & ~BIT(group)))
+			return -EOPNOTSUPP;
+		if (duty != pp->led_duty && (pp->led_duty_mask & ~BIT(group)))
+			return -EOPNOTSUPP;
+	}
+
+	pp->led_cycle_mask &= ~BIT(group);
+	pp->led_duty_mask &= ~BIT(group);
+
+	/* 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_OFF(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;
+
+	if (use_cycle) {
+		pp->led_cycle_mask |= BIT(group);
+		pp->led_cycle = cycle;
+	}
+	pp->led_duty_mask |= BIT(group);
+	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];
+	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;
+
+	pp->led_duty_mask &= ~BIT(group);
+	pp->led_cycle_mask &= ~BIT(group);
+
+	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 ? NULL : &dp->user->dev;
+	if (dsa_port_is_cpu(dp))
+		return !dp->conduit ? NULL : &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;
+	int polarity_orig;
+	bool active_high;
+	bool active_low;
+	u32 force_orig;
+	int polarity;
+	u32 group;
+	u32 mask;
+	u32 ctrl;
+	u32 val;
+	bool on;
+	int res;
+	int ret;
+
+	res = fwnode_property_read_u32(fwnode, "reg", &group);
+	if (res) {
+		dev_err(dev, "Missing LED reg for %pfw\n", fwnode);
+		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]) {
+		res = -EEXIST;
+		goto err;
+	}
+
+	active_high = fwnode_property_read_bool(fwnode, "active-high");
+	active_low = fwnode_property_read_bool(fwnode, "active-low");
+	if (active_high && active_low) {
+		dev_err(dev, "LED %02d:%02u cannot be both active-high and active-low\n",
+			port, group);
+		return -EINVAL;
+	}
+	polarity = active_high ? 1 : active_low ? -1 : 0;
+
+	led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
+	if (!led) {
+		res = -ENOMEM;
+		goto err;
+	}
+	pp->leds[group] = led;
+
+	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.
+	 */
+	polarity_orig = 0;
+	if (polarity) {
+		res = yt921x_reg_read(priv, YT921X_LED_PAR_INV, &val);
+		if (res)
+			goto err_inv;
+
+		mask = YT921X_LED_PAR_INV_INVnm(group, port);
+		ctrl = polarity > 0 ? val | mask : val & ~mask;
+		if (ctrl != val) {
+			res = yt921x_reg_write(priv, YT921X_LED_PAR_INV, ctrl);
+			if (res)
+				goto err_inv;
+
+			polarity_orig = -polarity;
+		}
+	}
+
+	force_orig = U32_MAX;
+	res = yt921x_reg_read(priv, YT921X_LED2_PORTn(port), &val);
+	if (res)
+		goto err_led2;
+	mask = YT921X_LED2_PORT_FORCEn_M(group);
+
+	switch (state) {
+	case LEDS_DEFSTATE_OFF:
+	case LEDS_DEFSTATE_ON:
+	default:
+		on = state == LEDS_DEFSTATE_ON;
+		ctrl = (val & ~mask) |
+		       (on ? YT921X_LED2_PORT_FORCEn_ON(group) :
+			YT921X_LED2_PORT_FORCEn_OFF(group));
+		if (ctrl != val) {
+			res = yt921x_reg_write(priv, YT921X_LED2_PORTn(port),
+					       ctrl);
+			if (res)
+				goto err_led2;
+
+			force_orig = val & mask;
+		}
+		break;
+	case LEDS_DEFSTATE_KEEP:
+		on = (val & mask) == YT921X_LED2_PORT_FORCEn_ON(group);
+		break;
+	}
+
+	mutex_unlock(&priv->reg_lock);
+
+	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_register;
+
+	return 0;
+
+err_register:
+	mutex_lock(&priv->reg_lock);
+	if (force_orig != U32_MAX) {
+		ret = yt921x_reg_update_bits(priv, YT921X_LED2_PORTn(port),
+					     YT921X_LED2_PORT_FORCEn_M(group),
+					     force_orig);
+		if (ret)
+			dev_err(dev,
+				"Failed to restore %s for LED %02d:%02u: %d\n",
+				"LED2_PORT", port, group, ret);
+	}
+err_led2:
+	if (polarity_orig) {
+		ret = yt921x_reg_toggle_bits(priv, YT921X_LED_PAR_INV,
+					     YT921X_LED_PAR_INV_INVnm(group, port),
+					     polarity_orig > 0);
+		if (ret)
+			dev_err(dev,
+				"Failed to restore %s for LED %02d:%02u: %d\n",
+				"LED_PAR_INV", port, group, ret);
+	}
+	mutex_unlock(&priv->reg_lock);
+
+err_inv:
+	pp->leds[group] = NULL;
+	devm_kfree(dev, led);
+
+err:
+	dev_err(dev, "Failed to initialize LED %02d:%02u: %d\n",
+		port, group, res);
+	return res;
+}
+
+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);
+
+	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);
+			pp->leds[group] = NULL;
+			devm_kfree(dev, led);
+		}
+	}
+
+	pp->led_duty_mask = 0;
+	pp->led_cycle_mask = 0;
+}
+
+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;
+	int res;
+
+	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, "Invalid port %d for LEDs\n", port);
+		of_node_put(leds_np);
+		return -EINVAL;
+	}
+
+	res = 0;
+	for_each_child_of_node_scoped(leds_np, led_np) {
+		res = yt921x_led_setup(priv, port, of_fwnode_handle(led_np));
+		if (res == -ENOMEM || res == -EIO)
+			break;
+		/* Allow partial configuration on non-fatal errors */
+		res = 0;
+	}
+
+	of_node_put(leds_np);
+	return res;
+}
+
+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;
+	int res;
+
+	/* LEDs are always enabled. There is no way to disable them altogether
+	 * (as far as I know).
+	 */
+
+	res = 0;
+	dsa_switch_for_each_port(dp, ds) {
+		if (!dp->dn)
+			continue;
+
+		res = yt921x_leds_setup_port(priv, dp->index);
+		if (res == -ENOMEM || res == -EIO)
+			break;
+		/* Allow partial configuration on non-fatal errors */
+		res = 0;
+	}
+
+	return res;
+}
diff --git a/drivers/net/dsa/motorcomm/leds.h b/drivers/net/dsa/motorcomm/leds.h
new file mode 100644
index 000000000000..11df479ee581
--- /dev/null
+++ b/drivers/net/dsa/motorcomm/leds.h
@@ -0,0 +1,118 @@
+/* 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;
+};
+
+#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 v12 5/5] 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>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.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 v12 0/5] net: dsa: motorcomm: Add LED support

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu,  3 Sep 2026 11:16:21 +0800 you wrote:
> 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.
> 
> v11: https://lore.kernel.org/r/20260831044818.4103477-1-mmyangfl@gmail.com
>   - handle one of *delay_on / *delay_off is zero
>   - fix error path for yt921x_led_setup()
> v10: https://lore.kernel.org/r/20260816193905.218112-1-mmyangfl@gmail.com
>   - new patch to fix lock status check
>   - LED control block redesigned
> 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
> 
> [...]

Here is the summary with links:
  - [net-next,v12,1/5] net: dsa: yt921x: Check lock status with lockdep_assert_held_once()
    https://git.kernel.org/netdev/net-next/c/b1950d0426aa
  - [net-next,v12,2/5] net: dsa: motorcomm: Move to subdirectory
    https://git.kernel.org/netdev/net-next/c/9c472a0d7c38
  - [net-next,v12,3/5] net: dsa: motorcomm: Split SMI module
    https://git.kernel.org/netdev/net-next/c/e9423a64d382
  - [net-next,v12,4/5] net: dsa: motorcomm: Add LED support
    (no matching commit)
  - [net-next,v12,5/5] dt-bindings: net: dsa: yt921x: Add LEDs definition example
    https://git.kernel.org/netdev/net-next/c/5f28f63c5d19

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [PATCH net-next v12 0/5] net: dsa: motorcomm: Add LED support

[Jakub Kicinski]

On Thu, 03 Sep 2026 03:30:15 +0000 patchwork-bot+netdevbpf@kernel.org
wrote:
>   - [net-next,v12,4/5] net: dsa: motorcomm: Add LED support
>     (no matching commit)

Sigh, I thought you said all the issues on v11 were false positives.
I merged v11, please send an incremental fix.

Re: [PATCH net-next v12 4/5] net: dsa: motorcomm: Add LED support

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] Missing mutex unlock on error path causes permanent deadlock
- [Low] Build failure due to dynamic array index in `container_of_const`
--

commit 6e291330945ad21e3fadada5285deeff7e1563e6
Author: David Yang <mmyangfl@gmail.com>
Subject: net: dsa: motorcomm: Add LED support

This patch adds LED support for the Motorcomm YT9215 ethernet switch chips.
It introduces standard LED class devices for each port, supporting parallel
mode and mapping to the hardware default state.

> diff --git a/drivers/net/dsa/motorcomm/leds.c b/drivers/net/dsa/motorcomm/leds.c
> new file mode 100644
> --- /dev/null
> +++ b/drivers/net/dsa/motorcomm/leds.c
> @@ -0,0 +1,666 @@
> +// 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])

[Severity: Low]
Does this macro definition cause a build failure? `container_of_const` uses
`offsetof()`, which requires array indices to be integer constant expressions.
Since `(pp)->index` is evaluated at runtime, this might result in a
"non-constant integer expression in offsetof" compiler error when compiling
with CONFIG_NET_DSA_YT921X_LEDS enabled.

[ ... ]

> +static int
> +yt921x_led_setup(struct yt921x_priv *priv, int port,
> +		 struct fwnode_handle *fwnode)
> +{
[ ... ]
> +	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.
> +	 */
> +	polarity_orig = 0;
> +	if (polarity) {
> +		res = yt921x_reg_read(priv, YT921X_LED_PAR_INV, &val);
> +		if (res)
> +			goto err_inv;
> +
> +		mask = YT921X_LED_PAR_INV_INVnm(group, port);
> +		ctrl = polarity > 0 ? val | mask : val & ~mask;
> +		if (ctrl != val) {
> +			res = yt921x_reg_write(priv, YT921X_LED_PAR_INV, ctrl);
> +			if (res)
> +				goto err_inv;
> +
> +			polarity_orig = -polarity;
> +		}
> +	}

[ ... ]

> +err_led2:
> +	if (polarity_orig) {
> +		ret = yt921x_reg_toggle_bits(priv, YT921X_LED_PAR_INV,
> +					     YT921X_LED_PAR_INV_INVnm(group, port),
> +					     polarity_orig > 0);
> +		if (ret)
> +			dev_err(dev,
> +				"Failed to restore %s for LED %02d:%02u: %d\n",
> +				"LED_PAR_INV", port, group, ret);
> +	}
> +	mutex_unlock(&priv->reg_lock);
> +
> +err_inv:
> +	pp->leds[group] = NULL;
> +	devm_kfree(dev, led);

[Severity: High]
Can jumping to `err_inv` cause a permanent deadlock? The lock
`priv->reg_lock` is acquired earlier in `yt921x_led_setup()`. If the read
or write to `YT921X_LED_PAR_INV` fails, the code jumps to the `err_inv`
label, which is located after the `mutex_unlock(&priv->reg_lock)` call.
This bypasses the unlock entirely and leaves the lock permanently acquired,
potentially hanging the device's control path on subsequent operations.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260903031630.356840-1-mmyangfl@gmail.com?part=4