[PATCH net-next v9 0/4] net: dsa: microchip: Add support for KSZ8995XA/KS8995XA

[PATCH net-next v9 0/4] net: dsa: microchip: Add support for KSZ8995XA/KS8995XA

[Linus Walleij]

This series breaks with the dated attempt to polish the old
KS8995 driver, and instead implement support for the KS8995XA
in the KSZ driver, and after that delete the old KS8995 driver.

The hardware clearly has the same ancestry, the KSZ8995XA is
just a rebrand of the much older Micrel KX8995XA switch.

The old driver identified the shared 0x95/0x0 ID as KS8995MA, but
this ID cannot distinguish MA from XA. No KS8995MA users are known,
and KS8995E has no documented SPI management interface. Neither
variant has been verified with the replacement driver.

Add new compatibles, add special code paths for the KSZ8995XA,
including support for its two-level DCB priority model, and add a
new tagger for the special front tag found in the KSZ8995XA.

The patches were tested with the Actiontec MI424WR rev D (which
has the KS8995XA) and OpenWrt as userspace.

Assisted-by: LLM
Signed-off-by: Linus Walleij <linusw@kernel.org>
---
Changes in v9:
- Fold the legacy Micrel compatibles into KSZ8995XA support and use an
  exact tristate dependency to avoid probe races and bisect gaps.
- Always prepend a distinct KS8995 switch tag to preserve existing VLAN
  headers and avoid unsafe MAC-header access on direct transmit paths.
- Rate-limit KS8995 receive untagging errors to avoid log flooding.
- Link to v8: https://patch.msgid.link/20260831-ks8995-to-ksz8-v8-0-fd1dbb2b76e8@kernel.org

Changes in v8:
- Add DCB support for the KSZ8995XA two-level priority model and set its
  internal priority map count to two.
- Initialize the KSZ8995XA per-port default tags to VID 0 so the tagger can
  distinguish originally untagged packets from VLAN-tagged frames.
- Push non-802.1Q hardware-accelerated VLAN tags into the packet before
  adding the KS8995 tag, so they cannot displace the switch tag from its
  required offset 12.
- Account for the discrepancy between the documented and observed
  KSZ8995XA MTU behavior. Its packet-size control bits use the same
  polarity as the other KSZ8 switches, while using the opposite polarity
  documented in the manual makes the switch hang on big packets.
- Rebased on v7.3-rc1
- Link to v7: https://patch.msgid.link/20260704-ks8995-to-ksz8-v7-0-2af0eaa545a8@kernel.org

Changes in v7:
- Rebased on v7.2-rc1
- Rebased on top of Bastiens cleanups.
- Rebased and reworked on top of my patch changing the SKB ownership
  model in the taggers.
- Drop bogus reset routine, keep per-port reset but use the right
  defines.
- Properly implement the 2way queue split support (low/hi prio)
- Drop bogus surplus ops assignment.
- Link to v6: https://patch.msgid.link/20260608-ks8995-to-ksz8-v6-0-d91eb43edcc5@kernel.org

Changes in v6:
- Provide a prompt along with the transition symbol NET_DSA_KS8995
  so that oldconfig works.
- Clarify in commit message that the platform data probe path is
  unused in the kernel and it is fine to delete this mechanism.
- Link to v5: https://patch.msgid.link/20260604-ks8995-to-ksz8-v5-0-98baeb45e665@kernel.org

Changes in v5:
- Rebase on net-next again to be sure we apply.
- Fix the codepath where DCB was set up per-port, damaging KS8995XA
  port registers.
- Fix up the transitional symbol NET_DSA_KS8995 to depend on
  SPI and select both NET_DSA_MICROCHIP_KSZ_COMMON and
  NET_DSA_MICROCHIP_KSZ_SPI.
- Link to v4: https://patch.msgid.link/20260603-ks8995-to-ksz8-v4-0-e15149ef21e7@kernel.org

Changes in v4:
- Create a stub symbol for NET_DSA_KS8995 to phase over users to
  the new driver.
- Link to v3: https://patch.msgid.link/20260526-ks8995-to-ksz8-v3-0-c530f651989f@kernel.org

Changes in v3:
- Rebase on net-next again, moving target!
- Fix a netdev_info() print in the tagger to be netdev_debug()
- Add net/dsa/tag_ks8995.c to MAINTAINERS
- Link to v2: https://patch.msgid.link/20260522-ks8995-to-ksz8-v2-0-5712c0dc9e75@kernel.org

Changes in v2:
- Avoid trying to configure TOS priority settings (DCB) on the KSZ8995XA.
  It does have some support for this, but let's add that later.
- Pick up Krzysztof's ACK on the new DT bindings.
- Reset the KSZ8995XA by disabling and enabling the switch like the old
  driver does.
- Move mutually exclusive Kconfig over to the patch introducing the
  old Micrel compatibles to the Microchip ksz_spi driver.
  (this complaint from Sashiko.)
- Use __be16 instead of u16 when casting into the SKB in the tagger
  (this complaint from Sashiko.)
- Do not modify the hdr->h_vlan_TCI if no hardware accelerated tag
  is detected, it would get nullified. Use whatever the Linux network stack
  assigned to TCI there.
  (this complaint from Sashiko.)
- Avoid dereference of NULL in debug prints in the tagger.
  (this complaint from Sashiko.)
- Ignored comment: Sashiko complains about ilog2(0) being potentially
  undefined but that is clearly defined as 0 in the Linux kernel.
- Link to v1: https://patch.msgid.link/20260516-ks8995-to-ksz8-v1-0-70d0ef4aa5f4@kernel.org

---
Linus Walleij (4):
      dt-bindings: net: dsa: microchip: Add KSZ8995XA
      net: dsa: tag_ks8995: Add the KS8995 tag handling
      net: dsa: microchip: Support Microchip KSZ8995XA / KS8995XA
      net: dsa: ks8995: Delete surplus driver

 .../devicetree/bindings/net/dsa/microchip,ksz.yaml |   1 +
 MAINTAINERS                                        |   1 +
 drivers/net/dsa/Kconfig                            |   9 +-
 drivers/net/dsa/Makefile                           |   1 -
 drivers/net/dsa/ks8995.c                           | 857 ---------------------
 drivers/net/dsa/microchip/Kconfig                  |   1 +
 drivers/net/dsa/microchip/ksz8.c                   | 205 ++++-
 drivers/net/dsa/microchip/ksz8.h                   |   2 +
 drivers/net/dsa/microchip/ksz8_reg.h               |   7 +
 drivers/net/dsa/microchip/ksz_common.c             |  53 +-
 drivers/net/dsa/microchip/ksz_common.h             |  11 +-
 drivers/net/dsa/microchip/ksz_dcb.c                |  55 +-
 drivers/net/dsa/microchip/ksz_spi.c                |  33 +-
 include/linux/platform_data/microchip-ksz.h        |   1 +
 include/net/dsa.h                                  |   2 +
 net/dsa/Kconfig                                    |   6 +
 net/dsa/Makefile                                   |   1 +
 net/dsa/tag_ks8995.c                               | 134 ++++
 18 files changed, 456 insertions(+), 924 deletions(-)
---
base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
change-id: 20260509-ks8995-to-ksz8-15f3f9c8271f

Best regards,
--  
Linus Walleij <linusw@kernel.org>

[PATCH net-next v9 1/4] dt-bindings: net: dsa: microchip: Add KSZ8995XA

[Linus Walleij]

The KSZ8995XA is just like the KSZ8795 and KSZ8864 a Micrel
product. It was renamed from KS8995XA to KSZ8995XA at some point,
but it has the same properties as the KS8995XA.

Be careful to use the full product name in this new compatible:
there is also KSZ8995MA and KSZ8995E which are not compatible
with the KS8995XA.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>
---
 Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
index 8d4a3a9a33fc..4ed13870ed3a 100644
--- a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
+++ b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
@@ -23,6 +23,7 @@ properties:
       - microchip,ksz8864  # 4-port version of KSZ8895 family switch
       - microchip,ksz8873
       - microchip,ksz8895  # 5-port version of KSZ8895 family switch
+      - microchip,ksz8995xa
       - microchip,ksz9477
       - microchip,ksz9897
       - microchip,ksz9896

-- 
2.55.0

[PATCH net-next v9 2/4] net: dsa: tag_ks8995: Add the KS8995 tag handling

[Linus Walleij]

The KS8995 100Mbit switch can do proper DSA per-port tagging
with the proper set-up. This adds the code to handle ingress
and egress KS8995 tags.

The tag is a modified 0x8100 ethertype tag where a bit in the
last nybble is set for each target port.

Always insert a distinct outer switch tag. User ports remove this
field on egress, so reusing an existing 802.1Q header would consume
the sender VLAN tag instead of preserving it.

Push any hardware-accelerated VLAN tag into the packet first. This
keeps the switch tag at offset 12 while retaining 802.1Q, 802.1ad and
stacked VLAN headers as inner payload, and avoids relying on a valid
SKB MAC header in direct transmit paths.

Rate-limit receive untagging errors so repeated failures cannot flood
the kernel log.

Assisted-by: LLM
Signed-off-by: Linus Walleij <linusw@kernel.org>
---
 MAINTAINERS          |   1 +
 include/net/dsa.h    |   2 +
 net/dsa/Kconfig      |   6 +++
 net/dsa/Makefile     |   1 +
 net/dsa/tag_ks8995.c | 134 +++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 144 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 3a19da74d00c..7fabc2eae9af 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17776,6 +17776,7 @@ F:	Documentation/devicetree/bindings/net/dsa/microchip,lan937x.yaml
 F:	drivers/net/dsa/microchip/*
 F:	include/linux/dsa/ksz_common.h
 F:	include/linux/platform_data/microchip-ksz.h
+F:	net/dsa/tag_ks8995.c
 F:	net/dsa/tag_ksz.c
 
 MICROCHIP LAN743X ETHERNET DRIVER
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 7507d632e7c6..5d12191b6f6f 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -61,6 +61,7 @@ struct tc_action;
 #define DSA_TAG_PROTO_NETC_VALUE		33
 #define DSA_TAG_PROTO_KSZ8463_VALUE		34
 #define DSA_TAG_PROTO_MT7628_VALUE		35
+#define DSA_TAG_PROTO_KS8995_VALUE		36
 
 enum dsa_tag_protocol {
 	DSA_TAG_PROTO_NONE		= DSA_TAG_PROTO_NONE_VALUE,
@@ -99,6 +100,7 @@ enum dsa_tag_protocol {
 	DSA_TAG_PROTO_NETC		= DSA_TAG_PROTO_NETC_VALUE,
 	DSA_TAG_PROTO_KSZ8463		= DSA_TAG_PROTO_KSZ8463_VALUE,
 	DSA_TAG_PROTO_MT7628		= DSA_TAG_PROTO_MT7628_VALUE,
+	DSA_TAG_PROTO_KS8995		= DSA_TAG_PROTO_KS8995_VALUE,
 };
 
 struct dsa_switch;
diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index 23b4b74004ed..4f44bf3ede23 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -125,6 +125,12 @@ config NET_DSA_TAG_MXL_GSW1XX
 	  Say Y or M if you want to enable support for tagging frames for
 	  MaxLinear GSW1xx switches.
 
+config NET_DSA_TAG_KS8995
+	tristate "Tag driver for Micrel KS8995 switch"
+	help
+	  Say Y if you want to enable support for tagging frames for the
+	  Micrel KS8995 switch.
+
 config NET_DSA_TAG_KSZ
 	tristate "Tag driver for Microchip 8795/937x/9477/9893 families of switches"
 	help
diff --git a/net/dsa/Makefile b/net/dsa/Makefile
index d15bcf5c68f0..1f9cc30e9988 100644
--- a/net/dsa/Makefile
+++ b/net/dsa/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_NET_DSA_TAG_BRCM_COMMON) += tag_brcm.o
 obj-$(CONFIG_NET_DSA_TAG_DSA_COMMON) += tag_dsa.o
 obj-$(CONFIG_NET_DSA_TAG_GSWIP) += tag_gswip.o
 obj-$(CONFIG_NET_DSA_TAG_HELLCREEK) += tag_hellcreek.o
+obj-$(CONFIG_NET_DSA_TAG_KS8995) += tag_ks8995.o
 obj-$(CONFIG_NET_DSA_TAG_KSZ) += tag_ksz.o
 obj-$(CONFIG_NET_DSA_TAG_LAN9303) += tag_lan9303.o
 obj-$(CONFIG_NET_DSA_TAG_MT7628) += tag_mt7628.o
diff --git a/net/dsa/tag_ks8995.c b/net/dsa/tag_ks8995.c
new file mode 100644
index 000000000000..db90b3165a85
--- /dev/null
+++ b/net/dsa/tag_ks8995.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2026 Linus Walleij <linusw@kernel.org>
+ */
+#include <linux/etherdevice.h>
+#include <linux/log2.h>
+#include <linux/list.h>
+#include <linux/net.h>
+#include <linux/slab.h>
+
+#include "tag.h"
+
+/* The Micrel KS8995XA / Microchip KSZ8995XA Special Tag Packet ID (STPID)
+ * pushes its tag in a modified VLAN (802.1Q) tag.
+ * -----------------------------------------------------------
+ * | MAC DA | MAC SA | 2 bytes tag | 2 bytes TCI | EtherType |
+ * -----------------------------------------------------------
+ * The tag is: 0x8100 |= BIT(port), ports 0,1,2,3
+ */
+
+#define KS8995_NAME "ks8995"
+
+#define KS8995M_STPID_STD	GENMASK(15, 4)
+#define KS8995M_STPID_PORTMASK	GENMASK(3, 0)
+#define KS8995M_STPID(portmask)	htons(ETH_P_8021Q | FIELD_PREP(KS8995M_STPID_PORTMASK, portmask))
+
+static struct sk_buff *ks8995_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct vlan_ethhdr *hdr;
+	u16 portmask;
+
+	/* Prepare the special KS8995 tags */
+	portmask = dsa_xmit_port_mask(skb, dev);
+
+	/* The switch expects the special tag at offset 12. Move any hardware
+	 * accelerated VLAN tag into the payload so the conduit cannot insert
+	 * it outside the special tag.
+	 */
+	if (unlikely(skb_vlan_tag_present(skb))) {
+		skb = __vlan_hwaccel_push_inside(skb);
+		if (!skb)
+			return NULL;
+	}
+
+	/* Always add a distinct outer tag. The user port removes this field on
+	 * egress, so reusing an existing 802.1Q tag would consume that VLAN tag.
+	 */
+	skb = vlan_insert_tag(skb, KS8995M_STPID(portmask), 0);
+	/* vlan_insert_tag() drops the skb on failure */
+	if (!skb)
+		return NULL;
+	hdr = skb_vlan_eth_hdr(skb);
+	netdev_dbg(dev, "%s: inserted VLAN TAG %04x TCI %04x\n",
+		   __func__, hdr->h_vlan_proto, hdr->h_vlan_TCI);
+
+	return skb;
+}
+
+static struct sk_buff *ks8995_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	int portmask;
+	u16 etype;
+
+	/* We are expecting all received packets to have a mangled VLAN
+	 * TPID, so drop anything else. Because of the non-standard TPID,
+	 * don't even bother looking for a tag in the hwaccel area.
+	 *
+	 * We have to inspect the ethertype directly because skb->protocol
+	 * will contain garbage.
+	 */
+	etype = ntohs(*(__be16 *)dsa_etype_header_pos_rx(skb));
+	if ((etype & KS8995M_STPID_STD) != ETH_P_8021Q) {
+		netdev_dbg(dev, "%s: dropped ethertype 0x%04x\n",
+			   __func__, etype);
+		kfree_skb(skb);
+		return NULL;
+	}
+	netdev_dbg(dev, "%s: received ethertype %04x\n",
+		   __func__, etype);
+
+	/* Move the custom DSA+VLAN tag into the hwaccel area and strip
+	 * it from the skb head
+	 */
+	skb = skb_vlan_untag(skb);
+	if (!skb) {
+		/* skb_vlan_untag drops the skb on failure */
+		if (net_ratelimit())
+			netdev_err(dev, "%s: unable to untag skb\n", __func__);
+		return NULL;
+	}
+
+	portmask = FIELD_GET(KS8995M_STPID_PORTMASK, etype);
+	netdev_dbg(dev, "%s: etype %04x portmask %04x (%d)\n",
+		   __func__, etype, portmask, ilog2(portmask));
+	skb->dev = dsa_conduit_find_user(dev, 0, ilog2(portmask));
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* skb_vlan_untag() moved the special tag's TCI into the hardware-
+	 * accelerated VLAN metadata. The switch preserves the TCI of tagged
+	 * frames, but inserts the ingress port's default tag for untagged frames.
+	 * Since the driver programs the default tag to 0, a zero TCI identifies
+	 * an originally untagged frame. Preserve every non-zero TCI as an
+	 * 802.1Q tag, including VID 0 frames with PCP or DEI set.
+	 */
+	if (!skb->vlan_tci) {
+		netdev_dbg(dev, "%s: clear VLAN tag from frame\n", __func__);
+		__vlan_hwaccel_clear_tag(skb);
+	} else {
+		skb->vlan_proto = htons(ETH_P_8021Q);
+		netdev_dbg(dev, "%s: vlan_tci = 0x%04x VLAN frame\n",
+			   __func__, skb->vlan_tci);
+	}
+
+	dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+static const struct dsa_device_ops ks8995_netdev_ops = {
+	.name = KS8995_NAME,
+	.proto	= DSA_TAG_PROTO_KS8995,
+	.xmit = ks8995_xmit,
+	.rcv = ks8995_rcv,
+	.needed_headroom = VLAN_HLEN,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for Micrel KS8995 family of switches");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KS8995, KS8995_NAME);
+
+module_dsa_tag_driver(ks8995_netdev_ops);

-- 
2.55.0

[PATCH net-next v9 3/4] net: dsa: microchip: Support Microchip KSZ8995XA / KS8995XA

[Linus Walleij]

This adds support for the Microchip KSZ8995XA also known as the
Micrel KS8995XA switch to the KSZ driver.

Notice: there are also KSZ8995E and KSZ8995MA. These are BOTH
different from the KSZ8995XA.

The helper macros are named ksz_is_ksz8995xa() to make it
possible to add E and MA support in the future.

The KSZ8995XA has eight global TOS priority registers with one
bit per DSCP code point, providing two internal priority levels.
The registers are ordered in the opposite direction from the
other KSZ8 switches. Describe the two priorities in the chip
data, then augment the DCB helpers for this.

Practical testing also shows that its packet-size control bits use
the same semantics as the other KSZ8 switches. The polarity in the
manual appears to be wrong and makes the switch hang on big packets.

The legacy KS8995 driver also matches the Micrel compatibles for
KSZ8864 and KSZ8795. Add these to the KSZ SPI driver here and use
an exact tristate dependency to make the drivers mutually exclusive.
This transfers ownership atomically, avoiding module probe races and
gaps in driver coverage between patches.

Assisted-by: LLM
Signed-off-by: Linus Walleij <linusw@kernel.org>
---
 drivers/net/dsa/Kconfig                     |   1 +
 drivers/net/dsa/microchip/Kconfig           |   1 +
 drivers/net/dsa/microchip/ksz8.c            | 205 +++++++++++++++++++++++-----
 drivers/net/dsa/microchip/ksz8.h            |   2 +
 drivers/net/dsa/microchip/ksz8_reg.h        |   7 +
 drivers/net/dsa/microchip/ksz_common.c      |  53 ++++++-
 drivers/net/dsa/microchip/ksz_common.h      |  11 +-
 drivers/net/dsa/microchip/ksz_dcb.c         |  55 +++++---
 drivers/net/dsa/microchip/ksz_spi.c         |  33 ++++-
 include/linux/platform_data/microchip-ksz.h |   1 +
 10 files changed, 306 insertions(+), 63 deletions(-)

diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
index 676fb7dffe14..e309e4c1ee3a 100644
--- a/drivers/net/dsa/Kconfig
+++ b/drivers/net/dsa/Kconfig
@@ -110,6 +110,7 @@ config NET_DSA_RZN1_A5PSW
 config NET_DSA_KS8995
 	tristate "Micrel KS8995 family 5-ports 10/100 Ethernet switches"
 	depends on SPI
+	depends on NET_DSA_MICROCHIP_KSZ_SPI = n
 	select NET_DSA_TAG_NONE
 	help
 	  This driver supports the Micrel KS8995 family of 10/100 Mbit ethernet
diff --git a/drivers/net/dsa/microchip/Kconfig b/drivers/net/dsa/microchip/Kconfig
index c71d3fd5dfeb..75c9b2114afd 100644
--- a/drivers/net/dsa/microchip/Kconfig
+++ b/drivers/net/dsa/microchip/Kconfig
@@ -2,6 +2,7 @@
 menuconfig NET_DSA_MICROCHIP_KSZ_COMMON
 	tristate "Microchip KSZ8XXX/KSZ9XXX/LAN937X series switch support"
 	depends on NET_DSA
+	select NET_DSA_TAG_KS8995
 	select NET_DSA_TAG_KSZ
 	select NET_DSA_TAG_NONE
 	select NET_IEEE8021Q_HELPERS
diff --git a/drivers/net/dsa/microchip/ksz8.c b/drivers/net/dsa/microchip/ksz8.c
index 941ae9f66f70..f9272d1b7bf4 100644
--- a/drivers/net/dsa/microchip/ksz8.c
+++ b/drivers/net/dsa/microchip/ksz8.c
@@ -3,6 +3,7 @@
  * Microchip KSZ8XXX series switch driver
  *
  * It supports the following switches:
+ * - KSZ8995XA (the oldest ancestor)
  * - KSZ8463
  * - KSZ8863, KSZ8873 aka KSZ88X3
  * - KSZ8895, KSZ8864 aka KSZ8895 family
@@ -253,7 +254,17 @@ static int ksz8463_reset_switch(struct ksz_device *dev)
 
 static int ksz8_reset_switch(struct ksz_device *dev)
 {
-	if (ksz_is_ksz88x3(dev)) {
+	if (ksz_is_ksz8995xa(dev)) {
+		unsigned int port;
+
+		/* The KSZ8995XA switch itself cannot be reset by software, but
+		 * often boot loaders have fun with ports, so reset them. This
+		 * reset bit is self-clearing.
+		 */
+		for (port = 0; port < dev->info->port_cnt; port++)
+			ksz_port_cfg(dev, port, REG_PORT_STATUS_3,
+				     PORT_PHY_SOFT_RESET, true);
+	} else if (ksz_is_ksz88x3(dev)) {
 		/* reset switch */
 		ksz_cfg(dev, KSZ8863_REG_SW_RESET,
 			KSZ8863_GLOBAL_SOFTWARE_RESET | KSZ8863_PCS_RESET, true);
@@ -269,6 +280,31 @@ static int ksz8_reset_switch(struct ksz_device *dev)
 	return 0;
 }
 
+static int ksz8995xa_change_mtu(struct dsa_switch *ds, int port, int mtu)
+{
+	struct ksz_device *dev = ds->priv;
+	int frame_size;
+	u8 ctrl2 = 0;
+
+	if (!dsa_is_cpu_port(dev->ds, port))
+		return 0;
+
+	frame_size = mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
+
+	/* The legal packet size bit polarity documented in the KSZ8995XA
+	 * manual appears to be wrong. Practical tests show that the same
+	 * semantics as the other switches are correct; using the documented
+	 * polarity makes the switch hang on big packets.
+	 */
+	if (frame_size <= KSZ8995XA_LEGAL_PACKET_SIZE)
+		ctrl2 |= KSZ8863_LEGAL_PACKET_ENABLE;
+	else if (frame_size > KSZ8863_NORMAL_PACKET_SIZE)
+		ctrl2 |= KSZ8863_HUGE_PACKET_ENABLE;
+
+	return ksz_rmw8(dev, REG_SW_CTRL_2, KSZ8863_LEGAL_PACKET_ENABLE |
+			KSZ8863_HUGE_PACKET_ENABLE, ctrl2);
+}
+
 static int ksz88xx_change_mtu(struct dsa_switch *ds, int port, int mtu)
 {
 	struct ksz_device *dev = ds->priv;
@@ -325,8 +361,8 @@ static int ksz88xx_max_mtu(struct dsa_switch *ds, int port)
 
 static int ksz8_port_queue_split(struct ksz_device *dev, int port, int queues)
 {
-	u8 mask_4q, mask_2q;
-	u8 reg_4q, reg_2q;
+	u8 mask_4q = 0, mask_2q;
+	u8 reg_4q = 0, reg_2q;
 	u8 data_4q = 0;
 	u8 data_2q = 0;
 	int ret;
@@ -352,6 +388,10 @@ static int ksz8_port_queue_split(struct ksz_device *dev, int port, int queues)
 		mask_2q = KSZ8873_PORT_2QUEUE_SPLIT_EN;
 		reg_4q = P1CR1;
 		reg_2q = P1CR1 + 1;
+	} else if (ksz_is_ksz8995xa(dev)) {
+		/* This switch has no 4way split support */
+		mask_2q = KSZ8795_PORT_2QUEUE_SPLIT_EN;
+		reg_2q = REG_PORT_CTRL_0;
 	} else {
 		mask_4q = KSZ8795_PORT_4QUEUE_SPLIT_EN;
 		mask_2q = KSZ8795_PORT_2QUEUE_SPLIT_EN;
@@ -373,9 +413,11 @@ static int ksz8_port_queue_split(struct ksz_device *dev, int port, int queues)
 	else if (queues == 2)
 		data_2q = mask_2q;
 
-	ret = ksz_prmw8(dev, port, reg_4q, mask_4q, data_4q);
-	if (ret)
-		return ret;
+	if (mask_4q) {
+		ret = ksz_prmw8(dev, port, reg_4q, mask_4q, data_4q);
+		if (ret)
+			return ret;
+	}
 
 	return ksz_prmw8(dev, port, reg_2q, mask_2q, data_2q);
 }
@@ -970,6 +1012,10 @@ static int ksz8_r_phy_ctrl(struct ksz_device *dev, int port, u16 *val)
 	if (reg_val & PORT_MDIX_STATUS)
 		*val |= KSZ886X_CTRL_MDIX_STAT;
 
+	/* KSZ8995XA has no fancy features in register 0xA */
+	if (ksz_is_ksz8995xa(dev))
+		return 0;
+
 	ret = ksz_pread8(dev, port, REG_PORT_LINK_MD_CTRL, &reg_val);
 	if (ret < 0)
 		return ret;
@@ -1068,8 +1114,10 @@ static int ksz8_r_phy_bmcr(struct ksz_device *dev, u16 port, u16 *val)
 	if (ctrl & PORT_FORCE_FULL_DUPLEX)
 		*val |= BMCR_FULLDPLX;
 
-	if (speed & PORT_HP_MDIX)
-		*val |= KSZ886X_BMCR_HP_MDIX;
+	if (!ksz_is_ksz8995xa(dev)) {
+		if (speed & PORT_HP_MDIX)
+			*val |= KSZ886X_BMCR_HP_MDIX;
+	}
 
 	if (restart & PORT_FORCE_MDIX)
 		*val |= KSZ886X_BMCR_FORCE_MDI;
@@ -1164,6 +1212,9 @@ static int ksz8_r_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 *val)
 			data |= LPA_LPACK;
 		break;
 	case PHY_REG_LINK_MD:
+		if (ksz_is_ksz8995xa(dev))
+			return -EOPNOTSUPP;
+
 		ret = ksz_pread8(dev, p, REG_PORT_LINK_MD_CTRL, &val1);
 		if (ret)
 			return ret;
@@ -1307,13 +1358,15 @@ static int ksz8_w_phy_bmcr(struct ksz_device *dev, u16 port, u16 val)
 	if (val & BMCR_RESET)
 		return 0;
 
-	speed = 0;
-	if (val & KSZ886X_BMCR_HP_MDIX)
-		speed |= PORT_HP_MDIX;
+	if (!ksz_is_ksz8995xa(dev)) {
+		speed = 0;
+		if (val & KSZ886X_BMCR_HP_MDIX)
+			speed |= PORT_HP_MDIX;
 
-	ret = ksz_prmw8(dev, port, regs[P_SPEED_STATUS], PORT_HP_MDIX, speed);
-	if (ret)
-		return ret;
+		ret = ksz_prmw8(dev, port, regs[P_SPEED_STATUS], PORT_HP_MDIX, speed);
+		if (ret)
+			return ret;
+	}
 
 	ctrl = 0;
 	if (ksz_is_ksz88x3(dev)) {
@@ -1423,11 +1476,17 @@ static int ksz8_w_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 val)
 		}
 		break;
 	case PHY_REG_LINK_MD:
+		if (ksz_is_ksz8995xa(dev))
+			return -EOPNOTSUPP;
+
 		if (val & PHY_START_CABLE_DIAG)
 			ksz_port_cfg(dev, p, REG_PORT_LINK_MD_CTRL, PORT_START_CABLE_DIAG, true);
 		break;
 
 	case PHY_REG_PHY_CTRL:
+		if (ksz_is_ksz8995xa(dev))
+			return -EOPNOTSUPP;
+
 		ret = ksz8_w_phy_ctrl(dev, p, val);
 		if (ret)
 			return ret;
@@ -1672,7 +1731,7 @@ static int ksz8_port_vlan_filtering(struct dsa_switch *ds, int port, bool flag,
 {
 	struct ksz_device *dev = ds->priv;
 
-	if (ksz_is_ksz88x3(dev))
+	if (ksz_is_ksz88x3(dev) || ksz_is_ksz8995xa(dev))
 		return -ENOTSUPP;
 
 	/* Discard packets with VID not enabled on the switch */
@@ -2043,12 +2102,14 @@ static void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 
 	ksz8_port_queue_split(dev, port, dev->info->num_tx_queues);
 
-	/* replace priority */
-	offset = P_802_1P_CTRL;
-	if (ksz_is_ksz8463(dev))
-		offset = P1CR2;
-	ksz_port_cfg(dev, port, offset,
-		     masks[PORT_802_1P_REMAPPING], false);
+	if (!ksz_is_ksz8995xa(dev)) {
+		/* replace priority */
+		offset = P_802_1P_CTRL;
+		if (ksz_is_ksz8463(dev))
+			offset = P1CR2;
+		ksz_port_cfg(dev, port, offset,
+			     masks[PORT_802_1P_REMAPPING], false);
+	}
 
 	if (cpu_port)
 		member = dsa_user_ports(ds);
@@ -2057,6 +2118,21 @@ static void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 
 	ksz8_cfg_port_member(dev, port, member);
 
+	if (ksz_is_ksz8995xa(dev)) {
+		/* Use VID 0 to identify untagged frames in the special tag */
+		ksz_pwrite16(dev, port, REG_PORT_CTRL_VID, 0);
+
+		/* The KSZ8995XA has a special tag format in the front of the frame
+		 * that need to be inserted by the CPU and then removed by each
+		 * port. PORT_REMOVE_TAG simply means "remove tags coming from the
+		 * CPU port" it does not affect ingress packets.
+		 */
+		if (cpu_port)
+			ksz_port_cfg(dev, port, REG_PORT_CTRL_0, PORT_INSERT_TAG, true);
+		else
+			ksz_port_cfg(dev, port, REG_PORT_CTRL_0, PORT_REMOVE_TAG, true);
+	}
+
 	/* Disable all WoL options by default. Otherwise
 	 * ksz_switch_macaddr_get/put logic will not work properly.
 	 * CPU port 4 has no WoL functionality.
@@ -2073,6 +2149,7 @@ static int ksz8_dsa_port_setup(struct dsa_switch *ds, int port)
 		return 0;
 
 	ksz8_port_setup(dev, port, false);
+
 	return ksz_dcb_init_port(dev, port);
 }
 
@@ -2147,7 +2224,9 @@ static void ksz8_config_cpu_port(struct dsa_switch *ds)
 	masks = dev->info->masks;
 	regs = dev->info->regs;
 
-	ksz_cfg(dev, regs[S_TAIL_TAG_CTRL], masks[SW_TAIL_TAG_ENABLE], true);
+	/* KSZ8995XA uses a tag in the header instead of the tail */
+	if (!ksz_is_ksz8995xa(dev))
+		ksz_cfg(dev, regs[S_TAIL_TAG_CTRL], masks[SW_TAIL_TAG_ENABLE], true);
 
 	ksz8_port_setup(dev, dev->cpu_port, true);
 
@@ -2323,6 +2402,10 @@ static int ksz8_enable_stp_addr(struct ksz_device *dev)
 {
 	struct alu_struct alu;
 
+	/* KSZ8995XA lacks STP */
+	if (ksz_is_ksz8995xa(dev))
+		return 0;
+
 	/* Setup STP address for STP operation. */
 	memset(&alu, 0, sizeof(alu));
 	ether_addr_copy(alu.mac, eth_stp_addr);
@@ -2650,13 +2733,17 @@ static int ksz8_setup(struct dsa_switch *ds)
 	struct ksz_port *p;
 	const u16 *regs;
 	int i, ret;
+	u8 val;
 
 	regs = dev->info->regs;
 
-	dev->vlan_cache = devm_kcalloc(dev->dev, sizeof(struct vlan_table),
-				       dev->info->num_vlans, GFP_KERNEL);
-	if (!dev->vlan_cache)
-		return -ENOMEM;
+	/* KSZ8995XA has no SW controlled VLAN handling */
+	if (!ksz_is_ksz8995xa(dev)) {
+		dev->vlan_cache = devm_kcalloc(dev->dev, sizeof(struct vlan_table),
+					       dev->info->num_vlans, GFP_KERNEL);
+		if (!dev->vlan_cache)
+			return -ENOMEM;
+	}
 
 	ret = ksz8_reset_switch(dev);
 	if (ret) {
@@ -2711,9 +2798,10 @@ static int ksz8_setup(struct dsa_switch *ds)
 	 * Make sure unicast VLAN boundary is set as default and
 	 * enable no excessive collision drop.
 	 */
-	ret = ksz_rmw8(dev, REG_SW_CTRL_2,
-		       UNICAST_VLAN_BOUNDARY | NO_EXC_COLLISION_DROP,
-		       UNICAST_VLAN_BOUNDARY | NO_EXC_COLLISION_DROP);
+	val = NO_EXC_COLLISION_DROP;
+	if (!ksz_is_ksz8995xa(dev))
+		val |= UNICAST_VLAN_BOUNDARY;
+	ret = ksz_rmw8(dev, REG_SW_CTRL_2, val, val);
 	if (ret)
 		return ret;
 
@@ -2721,11 +2809,15 @@ static int ksz8_setup(struct dsa_switch *ds)
 
 	ksz_cfg(dev, S_MIRROR_CTRL, SW_MIRROR_RX_TX, false);
 
-	if (!ksz_is_ksz88x3(dev))
+	if (ksz_is_ksz8995xa(dev))
+		ksz_cfg(dev, REG_SW_CTRL_9, SW_SPECIAL_TAG, true);
+	else if (!ksz_is_ksz88x3(dev))
 		ksz_cfg(dev, REG_SW_CTRL_19, SW_INS_TAG_ENABLE, true);
 
-	for (i = 0; i < (dev->info->num_vlans / 4); i++)
-		ksz8_r_vlan_entries(dev, i);
+	if (!ksz_is_ksz8995xa(dev)) {
+		for (i = 0; i < (dev->info->num_vlans / 4); i++)
+			ksz8_r_vlan_entries(dev, i);
+	}
 
 	/* Make sure PME (WoL) is not enabled. If requested, it will
 	 * be enabled by ksz_wol_pre_shutdown(). Otherwise, some PMICs
@@ -2976,6 +3068,13 @@ static int ksz8_switch_init(struct ksz_device *dev)
 	return 0;
 }
 
+static enum dsa_tag_protocol ksz8995xa_get_tag_protocol(struct dsa_switch *ds,
+							int port,
+							enum dsa_tag_protocol mp)
+{
+	return DSA_TAG_PROTO_KS8995;
+}
+
 static enum dsa_tag_protocol ksz8463_get_tag_protocol(struct dsa_switch *ds,
 						      int port,
 						      enum dsa_tag_protocol mp)
@@ -3072,6 +3171,16 @@ const struct phylink_mac_ops ksz8_phylink_mac_ops = {
 	.mac_enable_tx_lpi = ksz_phylink_mac_enable_tx_lpi,
 };
 
+/*
+ * The KS(Z)8995XA has no indirect access, meaning no MIB counters,
+ * no FDB access, and no VLAN handling.
+ */
+const struct ksz_dev_ops ksz8995xa_dev_ops = {
+	.get_port_addr = ksz8_get_port_addr,
+	.cfg_port_member = ksz8_cfg_port_member,
+	.init = ksz8_switch_init,
+};
+
 const struct ksz_dev_ops ksz8463_dev_ops = {
 	.get_port_addr = ksz8463_get_port_addr,
 	.cfg_port_member = ksz8_cfg_port_member,
@@ -3111,6 +3220,38 @@ const struct ksz_dev_ops ksz88xx_dev_ops = {
 	.pme_pwrite8 = ksz8_pme_pwrite8,
 };
 
+/*
+ * Restricted operations for KSZ8995XA, so many things are not supported
+ * by this old switch that we need diet DSA operations.
+ */
+const struct dsa_switch_ops ksz8995xa_switch_ops = {
+	.get_tag_protocol	= ksz8995xa_get_tag_protocol,
+	.setup			= ksz8_setup,
+	.teardown		= ksz_teardown,
+	.phy_read		= ksz8_phy_read16,
+	.phy_write		= ksz8_phy_write16,
+	.phylink_get_caps	= ksz8_phylink_get_caps,
+	.port_setup		= ksz8_dsa_port_setup,
+	.port_bridge_join	= ksz_port_bridge_join,
+	.port_bridge_leave	= ksz_port_bridge_leave,
+	.port_set_mac_address	= ksz_port_set_mac_address,
+	.port_stp_state_set	= ksz_port_stp_state_set,
+	.port_pre_bridge_flags	= ksz_port_pre_bridge_flags,
+	.port_bridge_flags	= ksz_port_bridge_flags,
+	.port_fast_age		= ksz8_flush_dyn_mac_table,
+	.port_mirror_add	= ksz8_port_mirror_add,
+	.port_mirror_del	= ksz8_port_mirror_del,
+	.port_change_mtu	= ksz8995xa_change_mtu,
+	.port_max_mtu		= ksz88xx_max_mtu,
+	.port_get_default_prio	= ksz_port_get_default_prio,
+	.port_set_default_prio	= ksz_port_set_default_prio,
+	.port_get_dscp_prio	= ksz_port_get_dscp_prio,
+	.port_add_dscp_prio	= ksz_port_add_dscp_prio,
+	.port_del_dscp_prio	= ksz_port_del_dscp_prio,
+	.port_get_apptrust	= ksz_port_get_apptrust,
+	.port_set_apptrust	= ksz_port_set_apptrust,
+};
+
 const struct dsa_switch_ops ksz8463_switch_ops = {
 	.get_tag_protocol	= ksz8463_get_tag_protocol,
 	.connect_tag_protocol   = ksz8463_connect_tag_protocol,
diff --git a/drivers/net/dsa/microchip/ksz8.h b/drivers/net/dsa/microchip/ksz8.h
index bc371cc26c6f..9b37c56c9617 100644
--- a/drivers/net/dsa/microchip/ksz8.h
+++ b/drivers/net/dsa/microchip/ksz8.h
@@ -12,11 +12,13 @@
 #include <net/dsa.h>
 #include "ksz_common.h"
 
+extern const struct ksz_dev_ops ksz8995xa_dev_ops;
 extern const struct ksz_dev_ops ksz8463_dev_ops;
 extern const struct ksz_dev_ops ksz87xx_dev_ops;
 extern const struct ksz_dev_ops ksz88xx_dev_ops;
 extern const struct phylink_mac_ops ksz88x3_phylink_mac_ops;
 extern const struct phylink_mac_ops ksz8_phylink_mac_ops;
+extern const struct dsa_switch_ops ksz8995xa_switch_ops;
 extern const struct dsa_switch_ops ksz8463_switch_ops;
 extern const struct dsa_switch_ops ksz87xx_switch_ops;
 extern const struct dsa_switch_ops ksz88xx_switch_ops;
diff --git a/drivers/net/dsa/microchip/ksz8_reg.h b/drivers/net/dsa/microchip/ksz8_reg.h
index 6bc511da1f7d..bd99699aae02 100644
--- a/drivers/net/dsa/microchip/ksz8_reg.h
+++ b/drivers/net/dsa/microchip/ksz8_reg.h
@@ -30,6 +30,11 @@
 #define KSZ88X3_REG_FVID_AND_HOST_MODE  0xC6
 #define KSZ88X3_PORT3_RMII_CLK_INTERNAL BIT(3)
 
+#define REG_SW_ID_0			0x00
+#define REG_SW_ID_1			0x01
+
+#define SW_START_SWITCH			BIT(0)
+
 #define REG_SW_CTRL_0			0x02
 
 #define SW_NEW_BACKOFF			BIT(7)
@@ -95,6 +100,8 @@
 #define SW_LED_LINK_ACT_DUPLEX		2
 #define SW_LED_LINK_DUPLEX		3
 
+#define SW_SPECIAL_TAG			BIT(0) /* KSZ8995XA only */
+
 #define REG_SW_CTRL_10			0x0C
 
 #define SW_PASS_PAUSE			BIT(0)
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 1a9d6f83a023..6c15ac97a7e3 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -446,6 +446,20 @@ static const u8 ksz8895_shifts[] = {
 	[DYNAMIC_MAC_SRC_PORT]		= 24,
 };
 
+static const u16 ksz8995xa_regs[] = {
+	[REG_SW_MAC_ADDR]		= 0x68,
+	[P_FORCE_CTRL]			= 0x0C,
+	[P_LINK_STATUS]			= 0x0E,
+	[P_LOCAL_CTRL]			= 0x0C,
+	[P_NEG_RESTART_CTRL]		= 0x0D,
+	[P_REMOTE_STATUS]		= 0x0E,
+	[P_SPEED_STATUS]		= 0x09,
+	[P_STP_CTRL]			= 0x02,
+	[S_START_CTRL]			= 0x01,
+	[S_BROADCAST_CTRL]		= 0x06,
+	[S_MULTICAST_CTRL]		= 0x04,
+};
+
 static const u16 ksz9477_regs[] = {
 	[REG_SW_MAC_ADDR]		= 0x0302,
 	[P_STP_CTRL]			= 0x0B04,
@@ -1377,6 +1391,21 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.internal_phy = {true, true, true, true, false},
 	},
 
+	[KSZ8995XA] = {
+		.chip_id = KSZ8995XA_CHIP_ID, /* Also known as KS8995XA */
+		.dev_name = "KSZ8995XA",
+		.cpu_ports = 0x10,	/* can be configured as cpu port */
+		.port_cnt = 5,		/* total cpu and user ports */
+		.num_tx_queues = 2,	/* low/hi priority queues, no more */
+		.num_ipms = 2,
+		.ops = &ksz8995xa_dev_ops,
+		.switch_ops = &ksz8995xa_switch_ops,
+		.phylink_mac_ops = &ksz88x3_phylink_mac_ops,
+		.regs = ksz8995xa_regs,
+		.supports_mii = {true, true, true, true, true},
+		.internal_phy = {true, true, true, true, false},
+	},
+
 	[KSZ9477] = {
 		.chip_id = KSZ9477_CHIP_ID,
 		.dev_name = "KSZ9477",
@@ -2649,6 +2678,10 @@ void ksz_init_mib_timer(struct ksz_device *dev)
 {
 	int i;
 
+	/* KSZ8995XA lacks MiB features */
+	if (ksz_is_ksz8995xa(dev))
+		return;
+
 	INIT_DELAYED_WORK(&dev->mib_read, ksz_mib_read_work);
 
 	for (i = 0; i < dev->info->port_cnt; i++) {
@@ -2944,11 +2977,15 @@ static int ksz_switch_detect(struct ksz_device *dev)
 			return -ENODEV;
 		break;
 	case KSZ8895_FAMILY_ID:
-		if (id2 == KSZ8895_CHIP_ID_95 ||
-		    id2 == KSZ8895_CHIP_ID_95R)
+		if (id2 == KSZ8895_CHIP_ID_95XA) {
+			dev->chip_id = KSZ8995XA_CHIP_ID;
+			break;
+		} else if (id2 == KSZ8895_CHIP_ID_95 ||
+			   id2 == KSZ8895_CHIP_ID_95R) {
 			dev->chip_id = KSZ8895_CHIP_ID;
-		else
+		} else {
 			return -ENODEV;
+		}
 		ret = ksz_read8(dev, REG_KSZ8864_CHIP_ID, &id4);
 		if (ret)
 			return ret;
@@ -4029,11 +4066,13 @@ int ksz_switch_register(struct ksz_device *dev)
 	if (ret)
 		return ret;
 
-	/* Read MIB counters every 30 seconds to avoid overflow. */
-	dev->mib_read_interval = msecs_to_jiffies(5000);
+	if (!ksz_is_ksz8995xa(dev)) {
+		/* Read MIB counters every 30 seconds to avoid overflow. */
+		dev->mib_read_interval = msecs_to_jiffies(5000);
 
-	/* Start the MIB timer. */
-	schedule_delayed_work(&dev->mib_read, 0);
+		/* Start the MIB timer. */
+		schedule_delayed_work(&dev->mib_read, 0);
+	}
 
 	return ret;
 }
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index cbe98494578c..93be74f7a265 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -281,6 +281,7 @@ enum ksz_model {
 	KSZ88X3,
 	KSZ8864,
 	KSZ8895,
+	KSZ8995XA,
 	KSZ9477,
 	KSZ9896,
 	KSZ9897,
@@ -789,7 +790,13 @@ static inline bool ksz_is_ksz88x3(struct ksz_device *dev)
 static inline bool ksz_is_8895_family(struct ksz_device *dev)
 {
 	return dev->chip_id == KSZ8895_CHIP_ID ||
-	       dev->chip_id == KSZ8864_CHIP_ID;
+	       dev->chip_id == KSZ8864_CHIP_ID ||
+	       dev->chip_id == KSZ8995XA_CHIP_ID;
+}
+
+static inline bool ksz_is_ksz8995xa(struct ksz_device *dev)
+{
+	return dev->chip_id == KSZ8995XA_CHIP_ID;
 }
 
 static inline bool is_ksz8(struct ksz_device *dev)
@@ -860,6 +867,7 @@ static inline bool ksz_is_sgmii_port(struct ksz_device *dev, int port)
 #define KSZ87_CHIP_ID_94		0x6
 #define KSZ87_CHIP_ID_95		0x9
 #define KSZ88_CHIP_ID_63		0x3
+#define KSZ8895_CHIP_ID_95XA		0x0
 #define KSZ8895_CHIP_ID_95		0x4
 #define KSZ8895_CHIP_ID_95R		0x6
 
@@ -923,6 +931,7 @@ static inline bool ksz_is_sgmii_port(struct ksz_device *dev, int port)
 #define KSZ8863_HUGE_PACKET_SIZE	1916
 #define KSZ8863_NORMAL_PACKET_SIZE	1536
 #define KSZ8_LEGAL_PACKET_SIZE		1518
+#define KSZ8995XA_LEGAL_PACKET_SIZE	1522
 #define KSZ9477_MAX_FRAME_SIZE		9000
 
 #define KSZ8873_REG_GLOBAL_CTRL_12	0x0e
diff --git a/drivers/net/dsa/microchip/ksz_dcb.c b/drivers/net/dsa/microchip/ksz_dcb.c
index 7131c5caac54..968de88e8ddd 100644
--- a/drivers/net/dsa/microchip/ksz_dcb.c
+++ b/drivers/net/dsa/microchip/ksz_dcb.c
@@ -20,10 +20,12 @@
 #define KSZ8_PORT_DIFFSERV_ENABLE		BIT(6)
 #define KSZ8_PORT_802_1P_ENABLE			BIT(5)
 #define KSZ8_PORT_BASED_PRIO_M			GENMASK(4, 3)
+#define KSZ8995XA_PORT_BASED_PRIO		BIT(4)
 
 #define KSZ8463_REG_TOS_DSCP_CTRL		0x16
 #define KSZ88X3_REG_TOS_DSCP_CTRL		0x60
 #define KSZ8765_REG_TOS_DSCP_CTRL		0x90
+#define KSZ8995XA_REG_TOS_DSCP_CTRL_7		0x67
 
 #define KSZ9477_REG_SW_MAC_TOS_CTRL		0x033e
 #define KSZ9477_SW_TOS_DSCP_REMAP		BIT(0)
@@ -98,8 +100,11 @@ static void ksz_get_default_port_prio_reg(struct ksz_device *dev, int *reg,
 {
 	if (is_ksz8(dev)) {
 		*reg = KSZ8_REG_PORT_1_CTRL_0;
-		*mask = KSZ8_PORT_BASED_PRIO_M;
-		*shift = __bf_shf(KSZ8_PORT_BASED_PRIO_M);
+		if (ksz_is_ksz8995xa(dev))
+			*mask = KSZ8995XA_PORT_BASED_PRIO;
+		else
+			*mask = KSZ8_PORT_BASED_PRIO_M;
+		*shift = __bf_shf(*mask);
 		if (ksz_is_ksz8463(dev))
 			*reg = KSZ8463_REG_PORT_1_CTRL_0;
 	} else {
@@ -112,31 +117,45 @@ static void ksz_get_default_port_prio_reg(struct ksz_device *dev, int *reg,
 /**
  * ksz_get_dscp_prio_reg - Retrieves the DSCP-to-priority-mapping register
  * @dev: Pointer to the KSZ switch device structure
+ * @dscp: DSCP value for which to retrieve the register
  * @reg: Pointer to the register address to be set
- * @per_reg: Pointer to the number of DSCP values per register
  * @mask: Pointer to the mask to be set
+ * @shift: Pointer to the bit shift to be set
  *
- * This function retrieves the DSCP to priority mapping register, the number of
- * DSCP values per register, and the mask to be set.
+ * This function retrieves the register, mask and shift for a DSCP to priority
+ * mapping entry.
  */
-static void ksz_get_dscp_prio_reg(struct ksz_device *dev, int *reg,
-				  int *per_reg, u8 *mask)
+static void ksz_get_dscp_prio_reg(struct ksz_device *dev, u8 dscp, int *reg,
+				  u8 *mask, int *shift)
 {
+	int per_reg;
+
+	if (ksz_is_ksz8995xa(dev)) {
+		/* KSZ8995XA stores DSCP groups in descending register order. */
+		*reg = KSZ8995XA_REG_TOS_DSCP_CTRL_7 - dscp / 8;
+		*mask = BIT(0);
+		*shift = dscp % 8;
+		return;
+	}
+
 	if (ksz_is_ksz87xx(dev) || ksz_is_8895_family(dev)) {
 		*reg = KSZ8765_REG_TOS_DSCP_CTRL;
-		*per_reg = 4;
+		per_reg = 4;
 		*mask = GENMASK(1, 0);
 	} else if (ksz_is_ksz88x3(dev) || ksz_is_ksz8463(dev)) {
 		*reg = KSZ88X3_REG_TOS_DSCP_CTRL;
-		*per_reg = 4;
+		per_reg = 4;
 		*mask = GENMASK(1, 0);
 		if (ksz_is_ksz8463(dev))
 			*reg = KSZ8463_REG_TOS_DSCP_CTRL;
 	} else {
 		*reg = KSZ9477_REG_DIFFSERV_PRIO_MAP;
-		*per_reg = 2;
+		per_reg = 2;
 		*mask = GENMASK(2, 0);
 	}
+
+	*reg += dscp / per_reg;
+	*shift = (dscp % per_reg) * (8 / per_reg);
 }
 
 /**
@@ -236,10 +255,10 @@ int ksz_port_set_default_prio(struct dsa_switch *ds, int port, u8 prio)
 int ksz_port_get_dscp_prio(struct dsa_switch *ds, int port, u8 dscp)
 {
 	struct ksz_device *dev = ds->priv;
-	int reg, per_reg, ret, shift;
+	int reg, ret, shift;
 	u8 data, mask;
 
-	ksz_get_dscp_prio_reg(dev, &reg, &per_reg, &mask);
+	ksz_get_dscp_prio_reg(dev, dscp, &reg, &mask, &shift);
 
 	/* If DSCP remapping is disabled, DSCP bits 3-5 are used as Internal
 	 * Priority Map (IPM)
@@ -260,13 +279,10 @@ int ksz_port_get_dscp_prio(struct dsa_switch *ds, int port, u8 dscp)
 	/* In case DSCP remapping is enabled, we need to write the DSCP to
 	 * priority mapping table.
 	 */
-	reg += dscp / per_reg;
 	ret = ksz_read8(dev, reg, &data);
 	if (ret)
 		return ret;
 
-	shift = (dscp % per_reg) * (8 / per_reg);
-
 	return (data >> shift) & mask;
 }
 
@@ -283,15 +299,12 @@ int ksz_port_get_dscp_prio(struct dsa_switch *ds, int port, u8 dscp)
  */
 static int ksz_set_global_dscp_entry(struct ksz_device *dev, u8 dscp, u8 ipm)
 {
-	int reg, per_reg, shift;
+	int reg, shift;
 	u8 mask;
 
-	ksz_get_dscp_prio_reg(dev, &reg, &per_reg, &mask);
-
-	shift = (dscp % per_reg) * (8 / per_reg);
+	ksz_get_dscp_prio_reg(dev, dscp, &reg, &mask, &shift);
 
-	return ksz_rmw8(dev, reg + (dscp / per_reg), mask << shift,
-			ipm << shift);
+	return ksz_rmw8(dev, reg, mask << shift, ipm << shift);
 }
 
 /**
diff --git a/drivers/net/dsa/microchip/ksz_spi.c b/drivers/net/dsa/microchip/ksz_spi.c
index 373e9054947c..2c55014246e5 100644
--- a/drivers/net/dsa/microchip/ksz_spi.c
+++ b/drivers/net/dsa/microchip/ksz_spi.c
@@ -161,7 +161,8 @@ static int ksz_spi_probe(struct spi_device *spi)
 		 chip->chip_id == KSZ8794_CHIP_ID ||
 		 chip->chip_id == KSZ8765_CHIP_ID)
 		regmap_config = ksz8795_regmap_config;
-	else if (chip->chip_id == KSZ8895_CHIP_ID ||
+	else if (chip->chip_id == KSZ8995XA_CHIP_ID ||
+		 chip->chip_id == KSZ8895_CHIP_ID ||
 		 chip->chip_id == KSZ8864_CHIP_ID)
 		regmap_config = ksz8863_regmap_config;
 	else
@@ -185,7 +186,10 @@ static int ksz_spi_probe(struct spi_device *spi)
 		dev->pdata = spi->dev.platform_data;
 
 	/* setup spi */
-	spi->mode = SPI_MODE_3;
+	if (chip->chip_id == KSZ8995XA_CHIP_ID)
+		spi->mode = SPI_MODE_0;
+	else
+		spi->mode = SPI_MODE_3;
 	ret = spi_setup(spi);
 	if (ret)
 		return ret;
@@ -224,6 +228,25 @@ static void ksz_spi_shutdown(struct spi_device *spi)
 }
 
 static const struct of_device_id ksz_dt_ids[] = {
+	/*
+	 * Legacy Micrel bindings. In 2015 Microchip acquired
+	 * Micrel which is the originator of the KSZ series, and
+	 * devices branded for Micrel already existed, as well as
+	 * some device tree bindings. These two products are identical
+	 * to the same Microchip products.
+	 */
+	{
+		.compatible = "micrel,ksz8864",
+		.data = &ksz_switch_chips[KSZ8864]
+	},
+	{
+		.compatible = "micrel,ksz8795",
+		.data = &ksz_switch_chips[KSZ8795]
+	},
+	{
+		.compatible = "micrel,ks8995",
+		.data = &ksz_switch_chips[KSZ8995XA]
+	},
 	{
 		.compatible = "microchip,ksz8463",
 		.data = &ksz_switch_chips[KSZ8463]
@@ -256,6 +279,10 @@ static const struct of_device_id ksz_dt_ids[] = {
 		.compatible = "microchip,ksz8895",
 		.data = &ksz_switch_chips[KSZ8895]
 	},
+	{
+		.compatible = "microchip,ksz8995xa",
+		.data = &ksz_switch_chips[KSZ8995XA]
+	},
 	{
 		.compatible = "microchip,ksz9477",
 		.data = &ksz_switch_chips[KSZ9477]
@@ -317,6 +344,7 @@ static const struct of_device_id ksz_dt_ids[] = {
 MODULE_DEVICE_TABLE(of, ksz_dt_ids);
 
 static const struct spi_device_id ksz_spi_ids[] = {
+	{ "ks8995" },
 	{ "ksz8463" },
 	{ "ksz8765" },
 	{ "ksz8794" },
@@ -325,6 +353,7 @@ static const struct spi_device_id ksz_spi_ids[] = {
 	{ "ksz8864" },
 	{ "ksz8873" },
 	{ "ksz8895" },
+	{ "ksz8995" },
 	{ "ksz9477" },
 	{ "ksz9896" },
 	{ "ksz9897" },
diff --git a/include/linux/platform_data/microchip-ksz.h b/include/linux/platform_data/microchip-ksz.h
index 028781ad4059..d8eddd21c3c7 100644
--- a/include/linux/platform_data/microchip-ksz.h
+++ b/include/linux/platform_data/microchip-ksz.h
@@ -31,6 +31,7 @@ enum ksz_chip_id {
 	KSZ88X3_CHIP_ID = 0x8830,
 	KSZ8864_CHIP_ID = 0x8864,
 	KSZ8895_CHIP_ID = 0x8895,
+	KSZ8995XA_CHIP_ID = 0x8995,
 	KSZ9477_CHIP_ID = 0x00947700,
 	KSZ9896_CHIP_ID = 0x00989600,
 	KSZ9897_CHIP_ID = 0x00989700,

-- 
2.55.0

[PATCH net-next v9 4/4] net: dsa: ks8995: Delete surplus driver

[Linus Walleij]

The Microchip KSZ driver now handles the KS(Z)8995XA. The old
driver identified the shared 0x95/0x0 ID as KS8995MA, but this ID
cannot distinguish MA from XA. No KS8995MA users are known, and
KS8995E has no documented SPI management interface. Neither variant
has been verified with the replacement driver.

Delete the old driver, but leave a stub behind in Kconfig so new
users will be automatically phased over to the new symbol when
migrating their configs.

The old driver supports platform data (board file) instantiation,
but nothing in the kernel tree makes use of this legacy mechanism so
it is fine to delete.

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Signed-off-by: Linus Walleij <linusw@kernel.org>
---
 drivers/net/dsa/Kconfig  |  10 +-
 drivers/net/dsa/Makefile |   1 -
 drivers/net/dsa/ks8995.c | 857 -----------------------------------------------
 3 files changed, 6 insertions(+), 862 deletions(-)

diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
index e309e4c1ee3a..55a9714033a6 100644
--- a/drivers/net/dsa/Kconfig
+++ b/drivers/net/dsa/Kconfig
@@ -110,11 +110,13 @@ config NET_DSA_RZN1_A5PSW
 config NET_DSA_KS8995
 	tristate "Micrel KS8995 family 5-ports 10/100 Ethernet switches"
 	depends on SPI
-	depends on NET_DSA_MICROCHIP_KSZ_SPI = n
-	select NET_DSA_TAG_NONE
+	select NET_DSA_MICROCHIP_KSZ_COMMON
+	select NET_DSA_MICROCHIP_KSZ_SPI
 	help
-	  This driver supports the Micrel KS8995 family of 10/100 Mbit ethernet
-	  switches, managed over SPI.
+	  This is a transitional option for users who had NET_DSA_KS8995
+	  enabled. It automatically enables the new NET_DSA_MICROCHIP_KSZ_SPI
+	  driver which supersedes it. This option will be removed in a future
+	  kernel release.
 
 config NET_DSA_SMSC_LAN9303
 	tristate
diff --git a/drivers/net/dsa/Makefile b/drivers/net/dsa/Makefile
index 6ceb78a755d7..9923137429f8 100644
--- a/drivers/net/dsa/Makefile
+++ b/drivers/net/dsa/Makefile
@@ -2,7 +2,6 @@
 obj-$(CONFIG_NET_DSA_BCM_SF2)	+= bcm-sf2.o
 bcm-sf2-objs			:= bcm_sf2.o bcm_sf2_cfp.o
 obj-$(CONFIG_NET_DSA_LOOP)	+= dsa_loop.o
-obj-$(CONFIG_NET_DSA_KS8995) 	+= ks8995.o
 obj-$(CONFIG_NET_DSA_MT7530)	+= mt7530.o
 obj-$(CONFIG_NET_DSA_MT7530_MDIO) += mt7530-mdio.o
 obj-$(CONFIG_NET_DSA_MT7530_MMIO) += mt7530-mmio.o
diff --git a/drivers/net/dsa/ks8995.c b/drivers/net/dsa/ks8995.c
deleted file mode 100644
index 77d8b842693c..000000000000
--- a/drivers/net/dsa/ks8995.c
+++ /dev/null
@@ -1,857 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * SPI driver for Micrel/Kendin KS8995M and KSZ8864RMN ethernet switches
- *
- * Copyright (C) 2008 Gabor Juhos <juhosg at openwrt.org>
- * Copyright (C) 2025 Linus Walleij <linus.walleij@linaro.org>
- *
- * This file was based on: drivers/spi/at25.c
- *     Copyright (C) 2006 David Brownell
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/bits.h>
-#include <linux/if_bridge.h>
-#include <linux/if_vlan.h>
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/delay.h>
-#include <linux/device.h>
-#include <linux/gpio/consumer.h>
-#include <linux/of.h>
-#include <linux/spi/spi.h>
-#include <net/dsa.h>
-
-#define DRV_VERSION		"0.1.1"
-#define DRV_DESC		"Micrel KS8995 Ethernet switch SPI driver"
-
-/* ------------------------------------------------------------------------ */
-
-#define KS8995_REG_ID0		0x00    /* Chip ID0 */
-#define KS8995_REG_ID1		0x01    /* Chip ID1 */
-
-#define KS8995_REG_GC0		0x02    /* Global Control 0 */
-
-#define KS8995_GC0_P5_PHY	BIT(3)	/* Port 5 PHY enabled */
-
-#define KS8995_REG_GC1		0x03    /* Global Control 1 */
-#define KS8995_REG_GC2		0x04    /* Global Control 2 */
-
-#define KS8995_GC2_HUGE		BIT(2)	/* Huge packet support */
-#define KS8995_GC2_LEGAL	BIT(1)	/* Legal size override */
-
-#define KS8995_REG_GC3		0x05    /* Global Control 3 */
-#define KS8995_REG_GC4		0x06    /* Global Control 4 */
-
-#define KS8995_GC4_10BT		BIT(4)	/* Force switch to 10Mbit */
-#define KS8995_GC4_MII_FLOW	BIT(5)	/* MII full-duplex flow control enable */
-#define KS8995_GC4_MII_HD	BIT(6)	/* MII half-duplex mode enable */
-
-#define KS8995_REG_GC5		0x07    /* Global Control 5 */
-#define KS8995_REG_GC6		0x08    /* Global Control 6 */
-#define KS8995_REG_GC7		0x09    /* Global Control 7 */
-#define KS8995_REG_GC8		0x0a    /* Global Control 8 */
-#define KS8995_REG_GC9		0x0b    /* Global Control 9 */
-
-#define KS8995_GC9_SPECIAL	BIT(0)	/* Special tagging mode (DSA) */
-
-/* In DSA the ports 1-4 are numbered 0-3 and the CPU port is port 4 */
-#define KS8995_REG_PC(p, r)	(0x10 + (0x10 * (p)) + (r)) /* Port Control */
-#define KS8995_REG_PS(p, r)	(0x1e + (0x10 * (p)) + (r)) /* Port Status */
-
-#define KS8995_REG_PC0		0x00    /* Port Control 0 */
-#define KS8995_REG_PC1		0x01    /* Port Control 1 */
-#define KS8995_REG_PC2		0x02    /* Port Control 2 */
-#define KS8995_REG_PC3		0x03    /* Port Control 3 */
-#define KS8995_REG_PC4		0x04    /* Port Control 4 */
-#define KS8995_REG_PC5		0x05    /* Port Control 5 */
-#define KS8995_REG_PC6		0x06    /* Port Control 6 */
-#define KS8995_REG_PC7		0x07    /* Port Control 7 */
-#define KS8995_REG_PC8		0x08    /* Port Control 8 */
-#define KS8995_REG_PC9		0x09    /* Port Control 9 */
-#define KS8995_REG_PC10		0x0a    /* Port Control 10 */
-#define KS8995_REG_PC11		0x0b    /* Port Control 11 */
-#define KS8995_REG_PC12		0x0c    /* Port Control 12 */
-#define KS8995_REG_PC13		0x0d    /* Port Control 13 */
-
-#define KS8995_PC0_TAG_INS	BIT(2)	/* Enable tag insertion on port */
-#define KS8995_PC0_TAG_REM	BIT(1)	/* Enable tag removal on port */
-#define KS8995_PC0_PRIO_EN	BIT(0)	/* Enable priority handling */
-
-#define KS8995_PC2_TXEN		BIT(2)	/* Enable TX on port */
-#define KS8995_PC2_RXEN		BIT(1)	/* Enable RX on port */
-#define KS8995_PC2_LEARN_DIS	BIT(0)	/* Disable learning on port */
-
-#define KS8995_PC13_TXDIS	BIT(6)	/* Disable transmitter */
-#define KS8995_PC13_PWDN	BIT(3)	/* Power down */
-
-#define KS8995_REG_TPC0		0x60    /* TOS Priority Control 0 */
-#define KS8995_REG_TPC1		0x61    /* TOS Priority Control 1 */
-#define KS8995_REG_TPC2		0x62    /* TOS Priority Control 2 */
-#define KS8995_REG_TPC3		0x63    /* TOS Priority Control 3 */
-#define KS8995_REG_TPC4		0x64    /* TOS Priority Control 4 */
-#define KS8995_REG_TPC5		0x65    /* TOS Priority Control 5 */
-#define KS8995_REG_TPC6		0x66    /* TOS Priority Control 6 */
-#define KS8995_REG_TPC7		0x67    /* TOS Priority Control 7 */
-
-#define KS8995_REG_MAC0		0x68    /* MAC address 0 */
-#define KS8995_REG_MAC1		0x69    /* MAC address 1 */
-#define KS8995_REG_MAC2		0x6a    /* MAC address 2 */
-#define KS8995_REG_MAC3		0x6b    /* MAC address 3 */
-#define KS8995_REG_MAC4		0x6c    /* MAC address 4 */
-#define KS8995_REG_MAC5		0x6d    /* MAC address 5 */
-
-#define KS8995_REG_IAC0		0x6e    /* Indirect Access Control 0 */
-#define KS8995_REG_IAC1		0x6f    /* Indirect Access Control 0 */
-#define KS8995_REG_IAD7		0x70    /* Indirect Access Data 7 */
-#define KS8995_REG_IAD6		0x71    /* Indirect Access Data 6 */
-#define KS8995_REG_IAD5		0x72    /* Indirect Access Data 5 */
-#define KS8995_REG_IAD4		0x73    /* Indirect Access Data 4 */
-#define KS8995_REG_IAD3		0x74    /* Indirect Access Data 3 */
-#define KS8995_REG_IAD2		0x75    /* Indirect Access Data 2 */
-#define KS8995_REG_IAD1		0x76    /* Indirect Access Data 1 */
-#define KS8995_REG_IAD0		0x77    /* Indirect Access Data 0 */
-
-#define KSZ8864_REG_ID1		0xfe	/* Chip ID in bit 7 */
-
-#define KS8995_REGS_SIZE	0x80
-#define KSZ8864_REGS_SIZE	0x100
-#define KSZ8795_REGS_SIZE	0x100
-
-#define ID1_CHIPID_M		0xf
-#define ID1_CHIPID_S		4
-#define ID1_REVISION_M		0x7
-#define ID1_REVISION_S		1
-#define ID1_START_SW		1	/* start the switch */
-
-#define FAMILY_KS8995		0x95
-#define FAMILY_KSZ8795		0x87
-#define CHIPID_M		0
-#define KS8995_CHIP_ID		0x00
-#define KSZ8864_CHIP_ID		0x01
-#define KSZ8795_CHIP_ID		0x09
-
-#define KS8995_CMD_WRITE	0x02U
-#define KS8995_CMD_READ		0x03U
-
-#define KS8995_CPU_PORT		4
-#define KS8995_NUM_PORTS	5 /* 5 ports including the CPU port */
-#define KS8995_RESET_DELAY	10 /* usec */
-
-enum ks8995_chip_variant {
-	ks8995,
-	ksz8864,
-	ksz8795,
-	max_variant
-};
-
-struct ks8995_chip_params {
-	char *name;
-	int family_id;
-	int chip_id;
-	int regs_size;
-	int addr_width;
-	int addr_shift;
-};
-
-static const struct ks8995_chip_params ks8995_chip[] = {
-	[ks8995] = {
-		.name = "KS8995MA",
-		.family_id = FAMILY_KS8995,
-		.chip_id = KS8995_CHIP_ID,
-		.regs_size = KS8995_REGS_SIZE,
-		.addr_width = 8,
-		.addr_shift = 0,
-	},
-	[ksz8864] = {
-		.name = "KSZ8864RMN",
-		.family_id = FAMILY_KS8995,
-		.chip_id = KSZ8864_CHIP_ID,
-		.regs_size = KSZ8864_REGS_SIZE,
-		.addr_width = 8,
-		.addr_shift = 0,
-	},
-	[ksz8795] = {
-		.name = "KSZ8795CLX",
-		.family_id = FAMILY_KSZ8795,
-		.chip_id = KSZ8795_CHIP_ID,
-		.regs_size = KSZ8795_REGS_SIZE,
-		.addr_width = 12,
-		.addr_shift = 1,
-	},
-};
-
-struct ks8995_switch {
-	struct spi_device	*spi;
-	struct device		*dev;
-	struct dsa_switch	*ds;
-	struct mutex		lock;
-	struct gpio_desc	*reset_gpio;
-	struct bin_attribute	regs_attr;
-	const struct ks8995_chip_params	*chip;
-	int			revision_id;
-	unsigned int max_mtu[KS8995_NUM_PORTS];
-};
-
-static const struct spi_device_id ks8995_id[] = {
-	{"ks8995", ks8995},
-	{"ksz8864", ksz8864},
-	{"ksz8795", ksz8795},
-	{ }
-};
-MODULE_DEVICE_TABLE(spi, ks8995_id);
-
-static const struct of_device_id ks8995_spi_of_match[] = {
-	{ .compatible = "micrel,ks8995" },
-	{ .compatible = "micrel,ksz8864" },
-	{ .compatible = "micrel,ksz8795" },
-	{ },
-};
-MODULE_DEVICE_TABLE(of, ks8995_spi_of_match);
-
-static inline u8 get_chip_id(u8 val)
-{
-	return (val >> ID1_CHIPID_S) & ID1_CHIPID_M;
-}
-
-static inline u8 get_chip_rev(u8 val)
-{
-	return (val >> ID1_REVISION_S) & ID1_REVISION_M;
-}
-
-/* create_spi_cmd - create a chip specific SPI command header
- * @ks: pointer to switch instance
- * @cmd: SPI command for switch
- * @address: register address for command
- *
- * Different chip families use different bit pattern to address the switches
- * registers:
- *
- * KS8995: 8bit command + 8bit address
- * KSZ8795: 3bit command + 12bit address + 1bit TR (?)
- */
-static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd,
-				    unsigned address)
-{
-	u16 result = cmd;
-
-	/* make room for address (incl. address shift) */
-	result <<= ks->chip->addr_width + ks->chip->addr_shift;
-	/* add address */
-	result |= address << ks->chip->addr_shift;
-	/* SPI protocol needs big endian */
-	return cpu_to_be16(result);
-}
-/* ------------------------------------------------------------------------ */
-static int ks8995_read(struct ks8995_switch *ks, char *buf,
-		 unsigned offset, size_t count)
-{
-	__be16 cmd;
-	struct spi_transfer t[2];
-	struct spi_message m;
-	int err;
-
-	cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset);
-	spi_message_init(&m);
-
-	memset(&t, 0, sizeof(t));
-
-	t[0].tx_buf = &cmd;
-	t[0].len = sizeof(cmd);
-	spi_message_add_tail(&t[0], &m);
-
-	t[1].rx_buf = buf;
-	t[1].len = count;
-	spi_message_add_tail(&t[1], &m);
-
-	mutex_lock(&ks->lock);
-	err = spi_sync(ks->spi, &m);
-	mutex_unlock(&ks->lock);
-
-	return err ? err : count;
-}
-
-static int ks8995_write(struct ks8995_switch *ks, char *buf,
-		 unsigned offset, size_t count)
-{
-	__be16 cmd;
-	struct spi_transfer t[2];
-	struct spi_message m;
-	int err;
-
-	cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset);
-	spi_message_init(&m);
-
-	memset(&t, 0, sizeof(t));
-
-	t[0].tx_buf = &cmd;
-	t[0].len = sizeof(cmd);
-	spi_message_add_tail(&t[0], &m);
-
-	t[1].tx_buf = buf;
-	t[1].len = count;
-	spi_message_add_tail(&t[1], &m);
-
-	mutex_lock(&ks->lock);
-	err = spi_sync(ks->spi, &m);
-	mutex_unlock(&ks->lock);
-
-	return err ? err : count;
-}
-
-static inline int ks8995_read_reg(struct ks8995_switch *ks, u8 addr, u8 *buf)
-{
-	return ks8995_read(ks, buf, addr, 1) != 1;
-}
-
-static inline int ks8995_write_reg(struct ks8995_switch *ks, u8 addr, u8 val)
-{
-	char buf = val;
-
-	return ks8995_write(ks, &buf, addr, 1) != 1;
-}
-
-/* ------------------------------------------------------------------------ */
-
-static int ks8995_stop(struct ks8995_switch *ks)
-{
-	return ks8995_write_reg(ks, KS8995_REG_ID1, 0);
-}
-
-static int ks8995_start(struct ks8995_switch *ks)
-{
-	return ks8995_write_reg(ks, KS8995_REG_ID1, 1);
-}
-
-static int ks8995_reset(struct ks8995_switch *ks)
-{
-	int err;
-
-	err = ks8995_stop(ks);
-	if (err)
-		return err;
-
-	udelay(KS8995_RESET_DELAY);
-
-	return ks8995_start(ks);
-}
-
-/* ks8995_get_revision - get chip revision
- * @ks: pointer to switch instance
- *
- * Verify chip family and id and get chip revision.
- */
-static int ks8995_get_revision(struct ks8995_switch *ks)
-{
-	int err;
-	u8 id0, id1, ksz8864_id;
-
-	/* read family id */
-	err = ks8995_read_reg(ks, KS8995_REG_ID0, &id0);
-	if (err) {
-		err = -EIO;
-		goto err_out;
-	}
-
-	/* verify family id */
-	if (id0 != ks->chip->family_id) {
-		dev_err(&ks->spi->dev, "chip family id mismatch: expected 0x%02x but 0x%02x read\n",
-			ks->chip->family_id, id0);
-		err = -ENODEV;
-		goto err_out;
-	}
-
-	switch (ks->chip->family_id) {
-	case FAMILY_KS8995:
-		/* try reading chip id at CHIP ID1 */
-		err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
-		if (err) {
-			err = -EIO;
-			goto err_out;
-		}
-
-		/* verify chip id */
-		if ((get_chip_id(id1) == CHIPID_M) &&
-		    (get_chip_id(id1) == ks->chip->chip_id)) {
-			/* KS8995MA */
-			ks->revision_id = get_chip_rev(id1);
-		} else if (get_chip_id(id1) != CHIPID_M) {
-			/* KSZ8864RMN */
-			err = ks8995_read_reg(ks, KS8995_REG_ID1, &ksz8864_id);
-			if (err) {
-				err = -EIO;
-				goto err_out;
-			}
-
-			if ((ksz8864_id & 0x80) &&
-			    (ks->chip->chip_id == KSZ8864_CHIP_ID)) {
-				ks->revision_id = get_chip_rev(id1);
-			}
-
-		} else {
-			dev_err(&ks->spi->dev, "unsupported chip id for KS8995 family: 0x%02x\n",
-				id1);
-			err = -ENODEV;
-		}
-		break;
-	case FAMILY_KSZ8795:
-		/* try reading chip id at CHIP ID1 */
-		err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);
-		if (err) {
-			err = -EIO;
-			goto err_out;
-		}
-
-		if (get_chip_id(id1) == ks->chip->chip_id) {
-			ks->revision_id = get_chip_rev(id1);
-		} else {
-			dev_err(&ks->spi->dev, "unsupported chip id for KSZ8795 family: 0x%02x\n",
-				id1);
-			err = -ENODEV;
-		}
-		break;
-	default:
-		dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0);
-		err = -ENODEV;
-		break;
-	}
-err_out:
-	return err;
-}
-
-static int ks8995_check_config(struct ks8995_switch *ks)
-{
-	int ret;
-	u8 val;
-
-	ret = ks8995_read_reg(ks, KS8995_REG_GC0, &val);
-	if (ret) {
-		dev_err(ks->dev, "failed to read KS8995_REG_GC0\n");
-		return ret;
-	}
-
-	dev_dbg(ks->dev, "port 5 PHY %senabled\n",
-		(val & KS8995_GC0_P5_PHY) ? "" : "not ");
-
-	val |= KS8995_GC0_P5_PHY;
-	ret = ks8995_write_reg(ks, KS8995_REG_GC0, val);
-	if (ret)
-		dev_err(ks->dev, "failed to set KS8995_REG_GC0\n");
-
-	dev_dbg(ks->dev, "set KS8995_REG_GC0 to 0x%02x\n", val);
-
-	return 0;
-}
-
-static void
-ks8995_mac_config(struct phylink_config *config, unsigned int mode,
-		  const struct phylink_link_state *state)
-{
-}
-
-static void
-ks8995_mac_link_up(struct phylink_config *config, struct phy_device *phydev,
-		   unsigned int mode, phy_interface_t interface,
-		   int speed, int duplex, bool tx_pause, bool rx_pause)
-{
-	struct dsa_port *dp = dsa_phylink_to_port(config);
-	struct ks8995_switch *ks = dp->ds->priv;
-	int port = dp->index;
-	int ret;
-	u8 val;
-
-	/* Allow forcing the mode on the fixed CPU port, no autonegotiation.
-	 * We assume autonegotiation works on the PHY-facing ports.
-	 */
-	if (port != KS8995_CPU_PORT)
-		return;
-
-	dev_dbg(ks->dev, "MAC link up on CPU port (%d)\n", port);
-
-	ret = ks8995_read_reg(ks, KS8995_REG_GC4, &val);
-	if (ret) {
-		dev_err(ks->dev, "failed to read KS8995_REG_GC4\n");
-		return;
-	}
-
-	/* Conjure port config */
-	switch (speed) {
-	case SPEED_10:
-		dev_dbg(ks->dev, "set switch MII to 100Mbit mode\n");
-		val |= KS8995_GC4_10BT;
-		break;
-	case SPEED_100:
-	default:
-		dev_dbg(ks->dev, "set switch MII to 100Mbit mode\n");
-		val &= ~KS8995_GC4_10BT;
-		break;
-	}
-
-	if (duplex == DUPLEX_HALF) {
-		dev_dbg(ks->dev, "set switch MII to half duplex\n");
-		val |= KS8995_GC4_MII_HD;
-	} else {
-		dev_dbg(ks->dev, "set switch MII to full duplex\n");
-		val &= ~KS8995_GC4_MII_HD;
-	}
-
-	dev_dbg(ks->dev, "set KS8995_REG_GC4 to %02x\n", val);
-
-	/* Enable the CPU port */
-	ret = ks8995_write_reg(ks, KS8995_REG_GC4, val);
-	if (ret)
-		dev_err(ks->dev, "failed to set KS8995_REG_GC4\n");
-}
-
-static void
-ks8995_mac_link_down(struct phylink_config *config, unsigned int mode,
-		     phy_interface_t interface)
-{
-	struct dsa_port *dp = dsa_phylink_to_port(config);
-	struct ks8995_switch *ks = dp->ds->priv;
-	int port = dp->index;
-
-	if (port != KS8995_CPU_PORT)
-		return;
-
-	dev_dbg(ks->dev, "MAC link down on CPU port (%d)\n", port);
-
-	/* Disable the CPU port */
-}
-
-static const struct phylink_mac_ops ks8995_phylink_mac_ops = {
-	.mac_config = ks8995_mac_config,
-	.mac_link_up = ks8995_mac_link_up,
-	.mac_link_down = ks8995_mac_link_down,
-};
-
-static enum
-dsa_tag_protocol ks8995_get_tag_protocol(struct dsa_switch *ds,
-					 int port,
-					 enum dsa_tag_protocol mp)
-{
-	/* This switch actually uses the 6 byte KS8995 protocol */
-	return DSA_TAG_PROTO_NONE;
-}
-
-static int ks8995_setup(struct dsa_switch *ds)
-{
-	return 0;
-}
-
-static int ks8995_port_enable(struct dsa_switch *ds, int port,
-			      struct phy_device *phy)
-{
-	struct ks8995_switch *ks = ds->priv;
-
-	dev_dbg(ks->dev, "enable port %d\n", port);
-
-	return 0;
-}
-
-static void ks8995_port_disable(struct dsa_switch *ds, int port)
-{
-	struct ks8995_switch *ks = ds->priv;
-
-	dev_dbg(ks->dev, "disable port %d\n", port);
-}
-
-static int ks8995_port_pre_bridge_flags(struct dsa_switch *ds, int port,
-					struct switchdev_brport_flags flags,
-					struct netlink_ext_ack *extack)
-{
-	/* We support enabling/disabling learning */
-	if (flags.mask & ~(BR_LEARNING))
-		return -EINVAL;
-
-	return 0;
-}
-
-static int ks8995_port_bridge_flags(struct dsa_switch *ds, int port,
-				    struct switchdev_brport_flags flags,
-				    struct netlink_ext_ack *extack)
-{
-	struct ks8995_switch *ks = ds->priv;
-	int ret;
-	u8 val;
-
-	if (flags.mask & BR_LEARNING) {
-		ret = ks8995_read_reg(ks, KS8995_REG_PC(port, KS8995_REG_PC2), &val);
-		if (ret) {
-			dev_err(ks->dev, "failed to read KS8995_REG_PC2 on port %d\n", port);
-			return ret;
-		}
-
-		if (flags.val & BR_LEARNING)
-			val &= ~KS8995_PC2_LEARN_DIS;
-		else
-			val |= KS8995_PC2_LEARN_DIS;
-
-		ret = ks8995_write_reg(ks, KS8995_REG_PC(port, KS8995_REG_PC2), val);
-		if (ret) {
-			dev_err(ks->dev, "failed to write KS8995_REG_PC2 on port %d\n", port);
-			return ret;
-		}
-	}
-
-	return 0;
-}
-
-static void ks8995_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
-{
-	struct ks8995_switch *ks = ds->priv;
-	int ret;
-	u8 val;
-
-	ret = ks8995_read_reg(ks, KS8995_REG_PC(port, KS8995_REG_PC2), &val);
-	if (ret) {
-		dev_err(ks->dev, "failed to read KS8995_REG_PC2 on port %d\n", port);
-		return;
-	}
-
-	/* Set the bits for the different STP states in accordance with
-	 * the datasheet, pages 36-37 "Spanning tree support".
-	 */
-	switch (state) {
-	case BR_STATE_DISABLED:
-	case BR_STATE_BLOCKING:
-	case BR_STATE_LISTENING:
-		val &= ~KS8995_PC2_TXEN;
-		val &= ~KS8995_PC2_RXEN;
-		val |= KS8995_PC2_LEARN_DIS;
-		break;
-	case BR_STATE_LEARNING:
-		val &= ~KS8995_PC2_TXEN;
-		val &= ~KS8995_PC2_RXEN;
-		val &= ~KS8995_PC2_LEARN_DIS;
-		break;
-	case BR_STATE_FORWARDING:
-		val |= KS8995_PC2_TXEN;
-		val |= KS8995_PC2_RXEN;
-		val &= ~KS8995_PC2_LEARN_DIS;
-		break;
-	default:
-		dev_err(ks->dev, "unknown bridge state requested\n");
-		return;
-	}
-
-	ret = ks8995_write_reg(ks, KS8995_REG_PC(port, KS8995_REG_PC2), val);
-	if (ret) {
-		dev_err(ks->dev, "failed to write KS8995_REG_PC2 on port %d\n", port);
-		return;
-	}
-
-	dev_dbg(ks->dev, "set KS8995_REG_PC2 for port %d to %02x\n", port, val);
-}
-
-static void ks8995_phylink_get_caps(struct dsa_switch *dsa, int port,
-				    struct phylink_config *config)
-{
-	unsigned long *interfaces = config->supported_interfaces;
-
-	if (port == KS8995_CPU_PORT)
-		__set_bit(PHY_INTERFACE_MODE_MII, interfaces);
-
-	if (port <= 3) {
-		/* Internal PHYs */
-		__set_bit(PHY_INTERFACE_MODE_INTERNAL, interfaces);
-		/* phylib default */
-		__set_bit(PHY_INTERFACE_MODE_MII, interfaces);
-	}
-
-	config->mac_capabilities = MAC_SYM_PAUSE | MAC_10 | MAC_100;
-}
-
-/* Huge packet support up to 1916 byte packages "inclusive"
- * which means that tags are included. If the bit is not set
- * it is 1536 bytes "inclusive". We present the length without
- * tags or ethernet headers. The setting affects all ports.
- */
-static int ks8995_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
-{
-	struct ks8995_switch *ks = ds->priv;
-	unsigned int max_mtu;
-	int ret;
-	u8 val;
-	int i;
-
-	ks->max_mtu[port] = new_mtu;
-
-	/* Roof out the MTU for the entire switch to the greatest
-	 * common denominator: the biggest set for any one port will
-	 * be the biggest MTU for the switch.
-	 */
-	max_mtu = ETH_DATA_LEN;
-	for (i = 0; i < KS8995_NUM_PORTS; i++) {
-		if (ks->max_mtu[i] > max_mtu)
-			max_mtu = ks->max_mtu[i];
-	}
-
-	/* Translate to layer 2 size.
-	 * Add ethernet and (possible) VLAN headers, and checksum to the size.
-	 * For ETH_DATA_LEN (1500 bytes) this will add up to 1522 bytes.
-	 */
-	max_mtu += VLAN_ETH_HLEN;
-	max_mtu += ETH_FCS_LEN;
-
-	ret = ks8995_read_reg(ks, KS8995_REG_GC2, &val);
-	if (ret) {
-		dev_err(ks->dev, "failed to read KS8995_REG_GC2\n");
-		return ret;
-	}
-
-	if (max_mtu <= 1522) {
-		val &= ~KS8995_GC2_HUGE;
-		val &= ~KS8995_GC2_LEGAL;
-	} else if (max_mtu > 1522 && max_mtu <= 1536) {
-		/* This accepts packets up to 1536 bytes */
-		val &= ~KS8995_GC2_HUGE;
-		val |= KS8995_GC2_LEGAL;
-	} else {
-		/* This accepts packets up to 1916 bytes */
-		val |= KS8995_GC2_HUGE;
-		val |= KS8995_GC2_LEGAL;
-	}
-
-	dev_dbg(ks->dev, "new max MTU %d bytes (inclusive)\n", max_mtu);
-
-	ret = ks8995_write_reg(ks, KS8995_REG_GC2, val);
-	if (ret)
-		dev_err(ks->dev, "failed to set KS8995_REG_GC2\n");
-
-	return ret;
-}
-
-static int ks8995_get_max_mtu(struct dsa_switch *ds, int port)
-{
-	return 1916 - ETH_HLEN - ETH_FCS_LEN;
-}
-
-static const struct dsa_switch_ops ks8995_ds_ops = {
-	.get_tag_protocol = ks8995_get_tag_protocol,
-	.setup = ks8995_setup,
-	.port_pre_bridge_flags = ks8995_port_pre_bridge_flags,
-	.port_bridge_flags = ks8995_port_bridge_flags,
-	.port_enable = ks8995_port_enable,
-	.port_disable = ks8995_port_disable,
-	.port_stp_state_set = ks8995_port_stp_state_set,
-	.port_change_mtu = ks8995_change_mtu,
-	.port_max_mtu = ks8995_get_max_mtu,
-	.phylink_get_caps = ks8995_phylink_get_caps,
-};
-
-/* ------------------------------------------------------------------------ */
-static int ks8995_probe(struct spi_device *spi)
-{
-	struct ks8995_switch *ks;
-	int err;
-	int variant = spi_get_device_id(spi)->driver_data;
-
-	if (variant >= max_variant) {
-		dev_err(&spi->dev, "bad chip variant %d\n", variant);
-		return -ENODEV;
-	}
-
-	ks = devm_kzalloc(&spi->dev, sizeof(*ks), GFP_KERNEL);
-	if (!ks)
-		return -ENOMEM;
-
-	mutex_init(&ks->lock);
-	ks->spi = spi;
-	ks->dev = &spi->dev;
-	ks->chip = &ks8995_chip[variant];
-
-	ks->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset",
-						 GPIOD_OUT_HIGH);
-	err = PTR_ERR_OR_ZERO(ks->reset_gpio);
-	if (err) {
-		dev_err(&spi->dev,
-			"failed to get reset gpio: %d\n", err);
-		return err;
-	}
-
-	err = gpiod_set_consumer_name(ks->reset_gpio, "switch-reset");
-	if (err)
-		return err;
-
-	if (ks->reset_gpio) {
-		/*
-		 * If a reset line was obtained, wait for 100us after
-		 * de-asserting RESET before accessing any registers, see
-		 * the KS8995MA datasheet, page 44.
-		 */
-		gpiod_set_value_cansleep(ks->reset_gpio, 0);
-		udelay(100);
-	}
-
-	spi_set_drvdata(spi, ks);
-
-	spi->mode = SPI_MODE_0;
-	spi->bits_per_word = 8;
-	err = spi_setup(spi);
-	if (err) {
-		dev_err(&spi->dev, "spi_setup failed, err=%d\n", err);
-		return err;
-	}
-
-	err = ks8995_get_revision(ks);
-	if (err)
-		return err;
-
-	err = ks8995_reset(ks);
-	if (err)
-		return err;
-
-	dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n",
-		 ks->chip->name, ks->chip->chip_id, ks->revision_id);
-
-	err = ks8995_check_config(ks);
-	if (err)
-		return err;
-
-	ks->ds = devm_kzalloc(&spi->dev, sizeof(*ks->ds), GFP_KERNEL);
-	if (!ks->ds)
-		return -ENOMEM;
-
-	ks->ds->dev = &spi->dev;
-	ks->ds->num_ports = KS8995_NUM_PORTS;
-	ks->ds->ops = &ks8995_ds_ops;
-	ks->ds->phylink_mac_ops = &ks8995_phylink_mac_ops;
-	ks->ds->priv = ks;
-
-	err = dsa_register_switch(ks->ds);
-	if (err)
-		return dev_err_probe(&spi->dev, err,
-				     "unable to register DSA switch\n");
-
-	return 0;
-}
-
-static void ks8995_remove(struct spi_device *spi)
-{
-	struct ks8995_switch *ks = spi_get_drvdata(spi);
-
-	dsa_unregister_switch(ks->ds);
-	/* assert reset */
-	gpiod_set_value_cansleep(ks->reset_gpio, 1);
-}
-
-/* ------------------------------------------------------------------------ */
-static struct spi_driver ks8995_driver = {
-	.driver = {
-		.name	    = "spi-ks8995",
-		.of_match_table = ks8995_spi_of_match,
-	},
-	.probe	  = ks8995_probe,
-	.remove	  = ks8995_remove,
-	.id_table = ks8995_id,
-};
-
-module_spi_driver(ks8995_driver);
-
-MODULE_DESCRIPTION(DRV_DESC);
-MODULE_VERSION(DRV_VERSION);
-MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
-MODULE_LICENSE("GPL v2");

-- 
2.55.0

Re: [PATCH net-next v9 1/4] dt-bindings: net: dsa: microchip: Add KSZ8995XA

[netdev-bot+sashiko]

Thank you for your contribution! Sashiko AI review found 1 potential
issue(s) to consider:

Critical: 0 · High: 0 · Medium: 0 · Low: 1

- [Low] Concern (verified as a FALSE POSITIVE by series validation): the
  new compatible `microchip,ksz8995xa` added to…

--

dt-bindings: net: dsa: microchip: Add KSZ8995XA

This adds a new compatible string microchip,ksz8995xa to the Microchip
KSZ switch family binding, described as having the same properties as
the older KS8995XA part. No other schema constraints are changed.

> diff --git a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
> index 8d4a3a9a33fcc..4ed13870ed3ac 100644
> --- a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
> +++ b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
> @@ -23,6 +23,7 @@ properties:
>        - microchip,ksz8864  # 4-port version of KSZ8895 family switch
>        - microchip,ksz8873
>        - microchip,ksz8895  # 5-port version of KSZ8895 family switch
> +      - microchip,ksz8995xa

[Severity: Low]
At this commit alone, is there any driver in tree that matches
microchip,ksz8995xa?  The existing part appears to be handled by the older
micrel,ks8995 binding and drivers/net/dsa/ks8995.c, so a device tree using
the new string would document a compatible that nothing binds to yet.

Checking the rest of the series, this looks already answered: the later
commit "net: dsa: microchip: Support Microchip KSZ8995XA / KS8995XA" adds

  drivers/net/dsa/microchip/ksz_spi.c:ksz_dt_ids
    { .compatible = "microchip,ksz8995xa",
      .data = &ksz_switch_chips[KSZ8995XA] },

along with ksz8995xa_regs[], ksz8995xa_dev_ops and ksz8995xa_switch_ops in
ksz_common.c, and "net: dsa: ks8995: Delete surplus driver" removes the
legacy driver and its micrel,* match table.  Documenting the binding one
patch ahead of the driver match entry is normal series ordering, so no
functional change results.

For completeness, the two if-then blocks in microchip,ksz.yaml (the
ksz8863/ksz8873 three-port block and the ksz8463 pinctrl/straps block) do
not appear to apply to this five-port part, so is it correct that neither
needs the new string added?

-- 
Sashiko AI review · https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260906-ks8995-to-ksz8-v9-0-8d8815a91bd8%40kernel.org

Re: [PATCH net-next v9 2/4] net: dsa: tag_ks8995: Add the KS8995 tag handling

[netdev-bot+sashiko]

Thank you for your contribution! Sashiko AI review found 2 potential
issue(s) to consider:

Critical: 0 · High: 0 · Medium: 0 · Low: 2

- [Low] Claimed incomplete submission: the new tag protocol
  DSA_TAG_PROTO_KS8995 / CONFIG_NET_DSA_TAG_KS8995 /…
- [Low] In ks8995_xmit() (net/dsa/tag_ks8995.c:52-54) the debug print
  passes the big-endian struct members hdr->h_vlan_proto and…

--

net: dsa: tag_ks8995: Add the KS8995 tag handling

This adds a new DSA tagger for the Micrel KS8995 / Microchip KSZ8995XA
switch, which carries its special tag in a modified 802.1Q header whose
last nybble holds the destination port mask.  The tagger inserts the
outer switch tag on xmit and moves the tag into the hwaccel VLAN area on
receive.

Two small observations below.

> diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
> index 23b4b74004ed5..4f44bf3ede238 100644
> --- a/net/dsa/Kconfig
> +++ b/net/dsa/Kconfig
> @@ -125,6 +125,12 @@ config NET_DSA_TAG_MXL_GSW1XX
>  	  Say Y or M if you want to enable support for tagging frames for
>  	  MaxLinear GSW1xx switches.
>  
> +config NET_DSA_TAG_KS8995
> +	tristate "Tag driver for Micrel KS8995 switch"
> +	help
> +	  Say Y if you want to enable support for tagging frames for the
> +	  Micrel KS8995 switch.
> +

[Severity: Low]
At this commit nothing in the tree selects NET_DSA_TAG_KS8995 and no
driver returns DSA_TAG_PROTO_KS8995, so the module can be built but never
bound.  The existing drivers/net/dsa/ks8995.c still returns
DSA_TAG_PROTO_NONE from ks8995_get_tag_protocol().

Looking further in the series this resolves itself: the following patch
adds ksz8995xa_get_tag_protocol() in drivers/net/dsa/microchip/ksz8.c
returning DSA_TAG_PROTO_KS8995 and makes
drivers/net/dsa/microchip/Kconfig select NET_DSA_TAG_KS8995, and the last
patch deletes the legacy drivers/net/dsa/ks8995.c.  Each patch still
compiles on its own.

Would it be worth mentioning in the commit message that the switch driver
side arrives in the next patch, so the tagger is intentionally without a
consumer for one commit?

>  config NET_DSA_TAG_KSZ
>  	tristate "Tag driver for Microchip 8795/937x/9477/9893 families of switches"
>  	help

[ ... ]

> diff --git a/net/dsa/tag_ks8995.c b/net/dsa/tag_ks8995.c
> new file mode 100644
> index 0000000000000..db90b3165a853
> --- /dev/null
> +++ b/net/dsa/tag_ks8995.c
> @@ -0,0 +1,134 @@

[ ... ]

> +	/* Always add a distinct outer tag. The user port removes this field on
> +	 * egress, so reusing an existing 802.1Q tag would consume that VLAN tag.
> +	 */
> +	skb = vlan_insert_tag(skb, KS8995M_STPID(portmask), 0);
> +	/* vlan_insert_tag() drops the skb on failure */
> +	if (!skb)
> +		return NULL;
> +	hdr = skb_vlan_eth_hdr(skb);
> +	netdev_dbg(dev, "%s: inserted VLAN TAG %04x TCI %04x\n",
> +		   __func__, hdr->h_vlan_proto, hdr->h_vlan_TCI);

[Severity: Low]
This isn't a bug in the packet path, but should these two values go
through ntohs() first?

Both members are big-endian in struct vlan_ethhdr (include/linux/if_vlan.h):

	__be16		h_vlan_proto;
	__be16		h_vlan_TCI;

On a little-endian host the tag just inserted (0x8101..0x810f) prints as
0x0181..0x0f81, which is not the value that goes on the wire, and sparse
with C=1 will complain about a restricted __be16 degrading to integer.

ks8995_rcv() in the same file converts before logging:

	etype = ntohs(*(__be16 *)dsa_etype_header_pos_rx(skb));
	...
	netdev_dbg(dev, "%s: received ethertype %04x\n", __func__, etype);

so printing ntohs(hdr->h_vlan_proto) / ntohs(hdr->h_vlan_TCI) here would
also make the two prints consistent.

> +
> +	return skb;
> +}

[ ... ]

-- 
Sashiko AI review · https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260906-ks8995-to-ksz8-v9-0-8d8815a91bd8%40kernel.org

Re: [PATCH net-next v9 3/4] net: dsa: microchip: Support Microchip KSZ8995XA / KS8995XA

[netdev-bot+sashiko]

Thank you for your contribution! Sashiko AI review found 4 potential
issue(s) to consider:

Critical: 0 · High: 0 · Medium: 1 · Low: 3

- [Medium] The generic legacy compatible "micrel,ks8995" is newly bound
  to ksz_switch_chips[KSZ8995XA] in drivers/net/dsa/microchip/ksz_spi.c,…
- [Low] ksz_spi.c now matches three compatible strings —
  "micrel,ksz8864", "micrel,ksz8795" and "micrel,ks8995" — that do not…
- [Low] The new KSZ8995XA branch of ksz8_reset_switch() iterates ports
  0..dev->info->port_cnt-1 (5 ports) writing PORT_PHY_SOFT_RESET…
- [Low] ksz8_port_vlan_filtering() gained a special case `if
  (ksz_is_ksz88x3(dev) || ksz_is_ksz8995xa(dev)) return -ENOTSUPP;`,…

--

net: dsa: microchip: Support Microchip KSZ8995XA / KS8995XA

This adds KSZ8995XA (Micrel KS8995XA) support to the KSZ driver, with a
restricted set of dev/switch ops, a header-tag protocol, one-bit-per-DSCP
priority registers and reworked DCB register helpers.  It also moves the
legacy Micrel compatibles over to the KSZ SPI driver and makes the old
ks8995 driver mutually exclusive with it in Kconfig.

> diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
> index 676fb7dffe14f..e309e4c1ee3a9 100644
> --- a/drivers/net/dsa/Kconfig
> +++ b/drivers/net/dsa/Kconfig
> @@ -110,6 +110,7 @@ config NET_DSA_RZN1_A5PSW
>  config NET_DSA_KS8995
>  	tristate "Micrel KS8995 family 5-ports 10/100 Ethernet switches"
>  	depends on SPI
> +	depends on NET_DSA_MICROCHIP_KSZ_SPI = n
>  	select NET_DSA_TAG_NONE
>  	help
>  	  This driver supports the Micrel KS8995 family of 10/100 Mbit ethernet

[ ... ]

> diff --git a/drivers/net/dsa/microchip/ksz8.c b/drivers/net/dsa/microchip/ksz8.c
> index 941ae9f66f70b..f9272d1b7bf47 100644
> --- a/drivers/net/dsa/microchip/ksz8.c
> +++ b/drivers/net/dsa/microchip/ksz8.c
> @@ -253,7 +254,17 @@ static int ksz8463_reset_switch(struct ksz_device *dev)
>  
>  static int ksz8_reset_switch(struct ksz_device *dev)
>  {
> -	if (ksz_is_ksz88x3(dev)) {
> +	if (ksz_is_ksz8995xa(dev)) {
> +		unsigned int port;
> +
> +		/* The KSZ8995XA switch itself cannot be reset by software, but
> +		 * often boot loaders have fun with ports, so reset them. This
> +		 * reset bit is self-clearing.
> +		 */
> +		for (port = 0; port < dev->info->port_cnt; port++)
> +			ksz_port_cfg(dev, port, REG_PORT_STATUS_3,
> +				     PORT_PHY_SOFT_RESET, true);

[Severity: Low]
This isn't a bug, but should this loop use dev->phy_port_cnt rather than
dev->info->port_cnt?

The chip data for KSZ8995XA has .port_cnt = 5 and
.internal_phy = {true, true, true, true, false}, so the last iteration
writes PORT_PHY_SOFT_RESET to the port 5 register block, and ksz8_reg.h
only names REG_PORT_1..4_STATUS_3.  Other PHY-oriented loops in ksz8.c
bound on dev->phy_port_cnt.

The legacy driver does define KS8995_GC0_P5_PHY BIT(3) /* Port 5 PHY
enabled */ and its KS8995_REG_PS(p, r) macro is valid for p = 0..4, so
this register does appear to exist on the hardware; it is just
inconsistent with how internal_phy[] is declared here.

> +	} else if (ksz_is_ksz88x3(dev)) {
>  		/* reset switch */
>  		ksz_cfg(dev, KSZ8863_REG_SW_RESET,
>  			KSZ8863_GLOBAL_SOFTWARE_RESET | KSZ8863_PCS_RESET, true);

[ ... ]

> @@ -1672,7 +1731,7 @@ static int ksz8_port_vlan_filtering(struct dsa_switch *ds, int port, bool flag,
>  {
>  	struct ksz_device *dev = ds->priv;
>  
> -	if (ksz_is_ksz88x3(dev))
> +	if (ksz_is_ksz88x3(dev) || ksz_is_ksz8995xa(dev))
>  		return -ENOTSUPP;

[Severity: Low]
Can this new ksz_is_ksz8995xa() branch ever be reached?

ksz8995xa_switch_ops (added further down in this patch) does not set
.port_vlan_filtering, and the core checks that first:

net/dsa/port.c:dsa_port_vlan_filtering() {
	...
	if (!ds->ops->port_vlan_filtering)
		return -EOPNOTSUPP;
	...
}

So for a KSZ8995XA device ksz8_port_vlan_filtering() is never entered and
the added condition looks like dead code that suggests the op is wired up.
As a side note, the existing return here is -ENOTSUPP while the core path
already returns the canonical -EOPNOTSUPP.

[ ... ]

> @@ -3111,6 +3220,38 @@ const struct ksz_dev_ops ksz88xx_dev_ops = {
> +/*
> + * Restricted operations for KSZ8995XA, so many things are not supported
> + * by this old switch that we need diet DSA operations.
> + */
> +const struct dsa_switch_ops ksz8995xa_switch_ops = {
> +	.get_tag_protocol	= ksz8995xa_get_tag_protocol,
> +	.setup			= ksz8_setup,
> +	.teardown		= ksz_teardown,
[ ... ]
> +	.port_get_apptrust	= ksz_port_get_apptrust,
> +	.port_set_apptrust	= ksz_port_set_apptrust,
> +};

> diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
> index 1a9d6f83a0232..6c15ac97a7e3f 100644
> --- a/drivers/net/dsa/microchip/ksz_common.c
> +++ b/drivers/net/dsa/microchip/ksz_common.c
> @@ -2944,11 +2977,15 @@ static int ksz_switch_detect(struct ksz_device *dev)
>  			return -ENODEV;
>  		break;
>  	case KSZ8895_FAMILY_ID:
> -		if (id2 == KSZ8895_CHIP_ID_95 ||
> -		    id2 == KSZ8895_CHIP_ID_95R)
> +		if (id2 == KSZ8895_CHIP_ID_95XA) {
> +			dev->chip_id = KSZ8995XA_CHIP_ID;
> +			break;
> +		} else if (id2 == KSZ8895_CHIP_ID_95 ||
> +			   id2 == KSZ8895_CHIP_ID_95R) {
>  			dev->chip_id = KSZ8895_CHIP_ID;
> -		else
> +		} else {
>  			return -ENODEV;
> +		}

[Severity: Medium]
The commit message says:

  "Notice: there are also KSZ8995E and KSZ8995MA. These are BOTH
   different from the KSZ8995XA."

Given that, is it safe for family 0x95 with chip ID nibble 0x0 to be
mapped unconditionally to KSZ8995XA_CHIP_ID here?

The legacy driver attributes that same ID to KS8995MA:

drivers/net/dsa/ks8995.c:
	[ks8995] = {
		.name		= "KS8995MA",
		.family_id	= FAMILY_KS8995,
		.chip_id	= KS8995_CHIP_ID,

and the new define in this patch is:

	#define KSZ8895_CHIP_ID_95XA		0x0

Combined with the new "micrel,ks8995" entry in ksz_dt_ids pointing at
ksz_switch_chips[KSZ8995XA], and with NET_DSA_KS8995 now disabled
whenever NET_DSA_MICROCHIP_KSZ_SPI is enabled, an MA part behind the
generic compatible would be probed and programmed as XA hardware:
SW_SPECIAL_TAG in REG_SW_CTRL_9, per-port PORT_INSERT_TAG /
PORT_REMOVE_TAG, PVID 0, the descending one-bit-per-DSCP registers, the
single-bit port-based priority and the inverted packet-size polarity,
plus DSA_TAG_PROTO_KS8995 from ksz8995xa_get_tag_protocol().

Two in-tree device trees use the generic string today,
arch/arm/boot/dts/intel/ixp/intel-ixp42x-linksys-wrv54g.dts and
intel-ixp42x-actiontec-mi424wr.dtsi, so if MA behaves differently in
special-tag mode those boards would lose CPU-port traffic.

For context, the later "net: dsa: ks8995: Delete surplus driver" patch in
the series records that this ID cannot distinguish MA from XA, that no
KS8995MA users are known and that neither variant has been verified, but
it does not change this mapping.  Could this detection either reject the
ambiguous case or at least warn?

> +		ret = ksz_read8(dev, REG_KSZ8864_CHIP_ID, &id4);
> +		if (ret)
> +			return ret;

[ ... ]

> diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
> index cbe98494578c3..93be74f7a2658 100644
> --- a/drivers/net/dsa/microchip/ksz_common.h
> +++ b/drivers/net/dsa/microchip/ksz_common.h
> @@ -860,6 +867,7 @@ static inline bool ksz_is_sgmii_port(struct ksz_device *dev, int port)
>  #define KSZ87_CHIP_ID_94		0x6
>  #define KSZ87_CHIP_ID_95		0x9
>  #define KSZ88_CHIP_ID_63		0x3
> +#define KSZ8895_CHIP_ID_95XA		0x0
>  #define KSZ8895_CHIP_ID_95		0x4
>  #define KSZ8895_CHIP_ID_95R		0x6

[ ... ]

> diff --git a/drivers/net/dsa/microchip/ksz_spi.c b/drivers/net/dsa/microchip/ksz_spi.c
> index 373e9054947cb..2c55014246e5f 100644
> --- a/drivers/net/dsa/microchip/ksz_spi.c
> +++ b/drivers/net/dsa/microchip/ksz_spi.c
> @@ -224,6 +228,25 @@ static void ksz_spi_shutdown(struct spi_device *spi)
>  }
>  
>  static const struct of_device_id ksz_dt_ids[] = {
> +	/*
> +	 * Legacy Micrel bindings. In 2015 Microchip acquired
> +	 * Micrel which is the originator of the KSZ series, and
> +	 * devices branded for Micrel already existed, as well as
> +	 * some device tree bindings. These two products are identical
> +	 * to the same Microchip products.
> +	 */
> +	{
> +		.compatible = "micrel,ksz8864",
> +		.data = &ksz_switch_chips[KSZ8864]
> +	},
> +	{
> +		.compatible = "micrel,ksz8795",
> +		.data = &ksz_switch_chips[KSZ8795]
> +	},
> +	{
> +		.compatible = "micrel,ks8995",
> +		.data = &ksz_switch_chips[KSZ8995XA]
> +	},

[Severity: Low]
Should the three Micrel strings also be added to the compatible enum in
Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml?

The series adds "microchip,ksz8995xa" to that enum, but "micrel,ksz8864",
"micrel,ksz8795" and "micrel,ks8995" are not listed anywhere under
Documentation/, and the legacy ks8995 driver is removed later in the
series, so the KSZ schema becomes the only place that could describe
them.  As a result the two ixp42x device trees using "micrel,ks8995"
stay unvalidated by dt_binding_check / dtbs_check.  Listing them (for
instance as deprecated) would close that gap.

> +	{
> +		.compatible = "microchip,ksz8463",
> +		.data = &ksz_switch_chips[KSZ8463]

[ ... ]

-- 
Sashiko AI review · https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260906-ks8995-to-ksz8-v9-0-8d8815a91bd8%40kernel.org

Re: [PATCH net-next v9 4/4] net: dsa: ks8995: Delete surplus driver

[netdev-bot+sashiko]

Thank you for your contribution! Sashiko AI review found 3 potential
issue(s) to consider:

Critical: 0 · High: 0 · Medium: 2 · Low: 1

- [Medium] Deleting drivers/net/dsa/ks8995.c leaves the ambiguous legacy
  compatible "micrel,ks8995" handled unconditionally as a KSZ8995XA by…
- [Medium] The SPI ID table entries added for the KS8995 migration do not
  line up with the DT compatibles they are supposed to cover.
- [Low] The transitional stub added by this patch
  (drivers/net/dsa/Kconfig:110-119) tells KS8995 users that…

--

net: dsa: ks8995: Delete surplus driver

This removes drivers/net/dsa/ks8995.c and its Makefile entry, and turns
NET_DSA_KS8995 into a transitional Kconfig stub that selects the Microchip
KSZ SPI driver instead. Users of the old driver are expected to be phased
over to NET_DSA_MICROCHIP_KSZ_SPI when they migrate their configs.

> diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
> index e309e4c1ee3a9..55a9714033a6f 100644
> --- a/drivers/net/dsa/Kconfig
> +++ b/drivers/net/dsa/Kconfig
> @@ -110,11 +110,13 @@ config NET_DSA_RZN1_A5PSW
>  config NET_DSA_KS8995
>  	tristate "Micrel KS8995 family 5-ports 10/100 Ethernet switches"
>  	depends on SPI
> -	depends on NET_DSA_MICROCHIP_KSZ_SPI = n
> -	select NET_DSA_TAG_NONE
> +	select NET_DSA_MICROCHIP_KSZ_COMMON
> +	select NET_DSA_MICROCHIP_KSZ_SPI

[Severity: Medium]
After this deletion, is the ambiguous "micrel,ks8995" compatible handled
only as a KSZ8995XA?  In ksz_spi.c the ksz_dt_ids table has:

	{
		.compatible = "micrel,ks8995",
		.data = &ksz_switch_chips[KSZ8995XA]
	},

and ksz_switch_detect() keeps that classification for the shared ID:

	case KSZ8895_FAMILY_ID:
		if (id2 == KSZ8895_CHIP_ID_95XA) {
			dev->chip_id = KSZ8995XA_CHIP_ID;

KSZ8895_CHIP_ID_95XA is 0x0, which is the 0x95/0x0 pair the commit message
describes as unable to distinguish MA from XA.

Does that mean MA silicon now gets programmed on the XA path?
ksz8_setup() does:

	if (ksz_is_ksz8995xa(dev))
		ksz_cfg(dev, REG_SW_CTRL_9, SW_SPECIAL_TAG, true);

and ksz8_port_setup() writes the per-port tag bits:

		if (cpu_port)
			ksz_port_cfg(dev, port, REG_PORT_CTRL_0, PORT_INSERT_TAG, true);
		else
			ksz_port_cfg(dev, port, REG_PORT_CTRL_0, PORT_REMOVE_TAG, true);

The tagging model also changes for these DT nodes: the deleted driver's
ks8995_get_tag_protocol() returned DSA_TAG_PROTO_NONE, while
ksz8995xa_get_tag_protocol() returns DSA_TAG_PROTO_KS8995.

Two in-tree device trees instantiate exactly this compatible:

	arch/arm/boot/dts/intel/ixp/intel-ixp42x-linksys-wrv54g.dts
	arch/arm/boot/dts/intel/ixp/intel-ixp42x-actiontec-mi424wr.dtsi

			compatible = "micrel,ks8995";

so both boards move to the XA path and to a different tagger.  Since the
commit message only says "No KS8995MA users are known" and "Neither variant
has been verified with the replacement driver", could it also mention these
two boards and the DSA_TAG_PROTO_NONE to DSA_TAG_PROTO_KS8995 change?

[Severity: Medium]
With all old KS8995 configurations now routed to ksz_spi.c, do the SPI ID
table and the compatible list there line up?  ksz_spi_ids contains:

	{ "ksz8995" },

but the compatible added for this part in ksz_dt_ids is:

	{
		.compatible = "microchip,ksz8995xa",
		.data = &ksz_switch_chips[KSZ8995XA]
	},

__spi_register_driver() strips the vendor prefix and looks up the remainder
with spi_match_id():

	drivers/spi/spi.c:__spi_register_driver() {
		...
			pr_warn("SPI driver %s has no spi_device_id for %s\n",
				sdrv->driver.name, of_id->compatible);
		...
	}

Does this print a warning on every registration of the ksz-switch driver,
and does module autoloading fail for a DT using "microchip,ksz8995xa"
because the uevent carries MODALIAS=spi:ksz8995xa while the module only
exports spi:ksz8995?  Renaming the entry to "ksz8995xa" would seem to cover
both.

Separately, the new "ks8995" ID carries no driver_data, and ksz_spi_probe()
takes the chip description only from the firmware node:

	chip = device_get_match_data(ddev);
	if (!chip)
		return -EINVAL;

so a board-file SPI device named "ks8995" cannot probe.  This part matches
the pre-existing convention of the whole ksz_spi ID table (none of the
entries carry driver_data) and the commit message's statement that nothing
in tree uses that mechanism, which does hold for the current tree.

[Severity: Low]
This isn't a bug, but the help text below points migrating users at
NET_DSA_MICROCHIP_KSZ_SPI, whose chip enumeration lives in the parent
menuconfig NET_DSA_MICROCHIP_KSZ_COMMON in drivers/net/dsa/microchip/Kconfig:

	  This driver adds support for Microchip KSZ8, KSZ9 and
	  LAN937X series switch chips, being KSZ8863/8873,
	  KSZ8895/8864, KSZ8794/8795/8765,
	  KSZ9477/9897/9896/9567/8567, KSZ9893/9563/8563 and
	  LAN9370/9371/9372/9373/9374.

That list does not mention KS8995 or KSZ8995XA, even though ksz_dt_ids has
both "micrel,ks8995" and "microchip,ksz8995xa" entries.  Could the chip list
be updated so users landing there find their device?

>  	help
> -	  This driver supports the Micrel KS8995 family of 10/100 Mbit ethernet
> -	  switches, managed over SPI.
> +	  This is a transitional option for users who had NET_DSA_KS8995
> +	  enabled. It automatically enables the new NET_DSA_MICROCHIP_KSZ_SPI
> +	  driver which supersedes it. This option will be removed in a future
> +	  kernel release.
>  
>  config NET_DSA_SMSC_LAN9303
>  	tristate

[ ... ]

-- 
Sashiko AI review · https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260906-ks8995-to-ksz8-v9-0-8d8815a91bd8%40kernel.org

Re: [PATCH net-next v9 3/4] net: dsa: microchip: Support Microchip KSZ8995XA / KS8995XA

[Linus Walleij]

Hi netdev-Sashiko,

new stuff every day! I like it :D

On Tue, Sep 8, 2026 at 5:49 AM <netdev-bot+sashiko@kernel.org> wrote:

> [Severity: Low]
> This isn't a bug, but should this loop use dev->phy_port_cnt rather than
> dev->info->port_cnt?

Actually no. The boot loaders reset also the CPU port.

> [Severity: Medium]
> The commit message says:
>
>   "Notice: there are also KSZ8995E and KSZ8995MA. These are BOTH
>    different from the KSZ8995XA."
>
> Given that, is it safe for family 0x95 with chip ID nibble 0x0 to be
> mapped unconditionally to KSZ8995XA_CHIP_ID here?

Actually yes, all known users are the XA variant.

Whenever/if an MA user appear, we will deal with that then.
We have no hardware to test this as things are today.

> Two in-tree device trees use the generic string today,
> arch/arm/boot/dts/intel/ixp/intel-ixp42x-linksys-wrv54g.dts and
> intel-ixp42x-actiontec-mi424wr.dtsi, so if MA behaves differently in
> special-tag mode those boards would lose CPU-port traffic.

Those in-tree users are the XA variant, so this is a non-issue.

> [Severity: Low]
> Should the three Micrel strings also be added to the compatible enum in
> Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml?

No. Device tree bindings are OS-neutral and do not change
because of Linux internal driver changes.

I will address the rest in v10.

Yours,
Linus Walleij

Re: [PATCH net-next v9 4/4] net: dsa: ks8995: Delete surplus driver

[Linus Walleij]

Hi netdev-Sashiko,

On Tue, Sep 8, 2026 at 5:49 AM <netdev-bot+sashiko@kernel.org> wrote:

> [Severity: Medium]
> After this deletion, is the ambiguous "micrel,ks8995" compatible handled
> only as a KSZ8995XA?  In ksz_spi.c the ksz_dt_ids table has:
(...)
> Does that mean MA silicon now gets programmed on the XA path?
(...)
> Two in-tree device trees instantiate exactly this compatible:
>
>         arch/arm/boot/dts/intel/ixp/intel-ixp42x-linksys-wrv54g.dts
>         arch/arm/boot/dts/intel/ixp/intel-ixp42x-actiontec-mi424wr.dtsi
>
>                         compatible = "micrel,ks8995";
>
> so both boards move to the XA path and to a different tagger.

As mentioned before, both of these boards use the XA variant.

I guess I'll just add this information to the cover letter so there
is context about this.

I will look into resolving the other comments.

Yours,
Linus Walleij