From: Tristram Ha <tristram.ha@microchip.com>

KSZ8463 does not use same set of registers as KSZ8863 so it is necessary
to change some registers when using KSZ8463.

Signed-off-by: Tristram Ha <tristram.ha@microchip.com>
---
v3
- Replace cpu_to_be16() with swab16() to avoid compiler warning

 drivers/net/dsa/microchip/ksz8.c       | 78 +++++++++++++++++++-------
 drivers/net/dsa/microchip/ksz_common.c | 35 +++++++++---
 drivers/net/dsa/microchip/ksz_dcb.c    | 10 +++-
 3 files changed, 94 insertions(+), 29 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8.c b/drivers/net/dsa/microchip/ksz8.c
index eb8a86eaa0cd..9b0ea77a081a 100644
--- a/drivers/net/dsa/microchip/ksz8.c
+++ b/drivers/net/dsa/microchip/ksz8.c
@@ -143,6 +143,11 @@ int ksz8_reset_switch(struct ksz_device *dev)
 			KSZ8863_GLOBAL_SOFTWARE_RESET | KSZ8863_PCS_RESET, true);
 		ksz_cfg(dev, KSZ8863_REG_SW_RESET,
 			KSZ8863_GLOBAL_SOFTWARE_RESET | KSZ8863_PCS_RESET, false);
+	} else if (ksz_is_ksz8463(dev)) {
+		ksz_cfg(dev, KSZ8463_REG_SW_RESET,
+			KSZ8463_GLOBAL_SOFTWARE_RESET, true);
+		ksz_cfg(dev, KSZ8463_REG_SW_RESET,
+			KSZ8463_GLOBAL_SOFTWARE_RESET, false);
 	} else {
 		/* reset switch */
 		ksz_write8(dev, REG_POWER_MANAGEMENT_1,
@@ -231,6 +236,11 @@ static int ksz8_port_queue_split(struct ksz_device *dev, int port, int queues)
 			       WEIGHTED_FAIR_QUEUE_ENABLE);
 		if (ret)
 			return ret;
+	} else if (ksz_is_ksz8463(dev)) {
+		mask_4q = KSZ8873_PORT_4QUEUE_SPLIT_EN;
+		mask_2q = KSZ8873_PORT_2QUEUE_SPLIT_EN;
+		reg_4q = P1CR1;
+		reg_2q = P1CR1 + 1;
 	} else {
 		mask_4q = KSZ8795_PORT_4QUEUE_SPLIT_EN;
 		mask_2q = KSZ8795_PORT_2QUEUE_SPLIT_EN;
@@ -1269,12 +1279,15 @@ int ksz8_w_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 val)
 
 void ksz8_cfg_port_member(struct ksz_device *dev, int port, u8 member)
 {
+	int offset = P_MIRROR_CTRL;
 	u8 data;
 
-	ksz_pread8(dev, port, P_MIRROR_CTRL, &data);
-	data &= ~PORT_VLAN_MEMBERSHIP;
+	if (ksz_is_ksz8463(dev))
+		offset = P1CR2;
+	ksz_pread8(dev, port, offset, &data);
+	data &= ~dev->port_mask;
 	data |= (member & dev->port_mask);
-	ksz_pwrite8(dev, port, P_MIRROR_CTRL, data);
+	ksz_pwrite8(dev, port, offset, data);
 }
 
 void ksz8_flush_dyn_mac_table(struct ksz_device *dev, int port)
@@ -1282,6 +1295,8 @@ void ksz8_flush_dyn_mac_table(struct ksz_device *dev, int port)
 	u8 learn[DSA_MAX_PORTS];
 	int first, index, cnt;
 	const u16 *regs;
+	int reg = S_FLUSH_TABLE_CTRL;
+	int mask = SW_FLUSH_DYN_MAC_TABLE;
 
 	regs = dev->info->regs;
 
@@ -1299,7 +1314,11 @@ void ksz8_flush_dyn_mac_table(struct ksz_device *dev, int port)
 			ksz_pwrite8(dev, index, regs[P_STP_CTRL],
 				    learn[index] | PORT_LEARN_DISABLE);
 	}
-	ksz_cfg(dev, S_FLUSH_TABLE_CTRL, SW_FLUSH_DYN_MAC_TABLE, true);
+	if (ksz_is_ksz8463(dev)) {
+		reg = KSZ8463_FLUSH_TABLE_CTRL;
+		mask = KSZ8463_FLUSH_DYN_MAC_TABLE;
+	}
+	ksz_cfg(dev, reg, mask, true);
 	for (index = first; index < cnt; index++) {
 		if (!(learn[index] & PORT_LEARN_DISABLE))
 			ksz_pwrite8(dev, index, regs[P_STP_CTRL], learn[index]);
@@ -1438,7 +1457,7 @@ int ksz8_fdb_del(struct ksz_device *dev, int port, const unsigned char *addr,
 int ksz8_port_vlan_filtering(struct ksz_device *dev, int port, bool flag,
 			     struct netlink_ext_ack *extack)
 {
-	if (ksz_is_ksz88x3(dev))
+	if (ksz_is_ksz88x3(dev) || ksz_is_ksz8463(dev))
 		return -ENOTSUPP;
 
 	/* Discard packets with VID not enabled on the switch */
@@ -1454,9 +1473,12 @@ int ksz8_port_vlan_filtering(struct ksz_device *dev, int port, bool flag,
 
 static void ksz8_port_enable_pvid(struct ksz_device *dev, int port, bool state)
 {
-	if (ksz_is_ksz88x3(dev)) {
-		ksz_cfg(dev, REG_SW_INSERT_SRC_PVID,
-			0x03 << (4 - 2 * port), state);
+	if (ksz_is_ksz88x3(dev) || ksz_is_ksz8463(dev)) {
+		int reg = REG_SW_INSERT_SRC_PVID;
+
+		if (ksz_is_ksz8463(dev))
+			reg = KSZ8463_REG_SW_CTRL_9;
+		ksz_cfg(dev, reg, 0x03 << (4 - 2 * port), state);
 	} else {
 		ksz_pwrite8(dev, port, REG_PORT_CTRL_12, state ? 0x0f : 0x00);
 	}
@@ -1471,7 +1493,7 @@ int ksz8_port_vlan_add(struct ksz_device *dev, int port,
 	u16 data, new_pvid = 0;
 	u8 fid, member, valid;
 
-	if (ksz_is_ksz88x3(dev))
+	if (ksz_is_ksz88x3(dev) || ksz_is_ksz8463(dev))
 		return -ENOTSUPP;
 
 	/* If a VLAN is added with untagged flag different from the
@@ -1540,7 +1562,7 @@ int ksz8_port_vlan_del(struct ksz_device *dev, int port,
 	u16 data, pvid;
 	u8 fid, member, valid;
 
-	if (ksz_is_ksz88x3(dev))
+	if (ksz_is_ksz88x3(dev) || ksz_is_ksz8463(dev))
 		return -ENOTSUPP;
 
 	ksz_pread16(dev, port, REG_PORT_CTRL_VID, &pvid);
@@ -1570,19 +1592,23 @@ int ksz8_port_mirror_add(struct ksz_device *dev, int port,
 			 struct dsa_mall_mirror_tc_entry *mirror,
 			 bool ingress, struct netlink_ext_ack *extack)
 {
+	int offset = P_MIRROR_CTRL;
+
+	if (ksz_is_ksz8463(dev))
+		offset = P1CR2;
 	if (ingress) {
-		ksz_port_cfg(dev, port, P_MIRROR_CTRL, PORT_MIRROR_RX, true);
+		ksz_port_cfg(dev, port, offset, PORT_MIRROR_RX, true);
 		dev->mirror_rx |= BIT(port);
 	} else {
-		ksz_port_cfg(dev, port, P_MIRROR_CTRL, PORT_MIRROR_TX, true);
+		ksz_port_cfg(dev, port, offset, PORT_MIRROR_TX, true);
 		dev->mirror_tx |= BIT(port);
 	}
 
-	ksz_port_cfg(dev, port, P_MIRROR_CTRL, PORT_MIRROR_SNIFFER, false);
+	ksz_port_cfg(dev, port, offset, PORT_MIRROR_SNIFFER, false);
 
 	/* configure mirror port */
 	if (dev->mirror_rx || dev->mirror_tx)
-		ksz_port_cfg(dev, mirror->to_local_port, P_MIRROR_CTRL,
+		ksz_port_cfg(dev, mirror->to_local_port, offset,
 			     PORT_MIRROR_SNIFFER, true);
 
 	return 0;
@@ -1591,20 +1617,23 @@ int ksz8_port_mirror_add(struct ksz_device *dev, int port,
 void ksz8_port_mirror_del(struct ksz_device *dev, int port,
 			  struct dsa_mall_mirror_tc_entry *mirror)
 {
+	int offset = P_MIRROR_CTRL;
 	u8 data;
 
+	if (ksz_is_ksz8463(dev))
+		offset = P1CR2;
 	if (mirror->ingress) {
-		ksz_port_cfg(dev, port, P_MIRROR_CTRL, PORT_MIRROR_RX, false);
+		ksz_port_cfg(dev, port, offset, PORT_MIRROR_RX, false);
 		dev->mirror_rx &= ~BIT(port);
 	} else {
-		ksz_port_cfg(dev, port, P_MIRROR_CTRL, PORT_MIRROR_TX, false);
+		ksz_port_cfg(dev, port, offset, PORT_MIRROR_TX, false);
 		dev->mirror_tx &= ~BIT(port);
 	}
 
-	ksz_pread8(dev, port, P_MIRROR_CTRL, &data);
+	ksz_pread8(dev, port, offset, &data);
 
 	if (!dev->mirror_rx && !dev->mirror_tx)
-		ksz_port_cfg(dev, mirror->to_local_port, P_MIRROR_CTRL,
+		ksz_port_cfg(dev, mirror->to_local_port, offset,
 			     PORT_MIRROR_SNIFFER, false);
 }
 
@@ -1629,17 +1658,24 @@ void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 	const u16 *regs = dev->info->regs;
 	struct dsa_switch *ds = dev->ds;
 	const u32 *masks;
+	int offset;
 	u8 member;
 
 	masks = dev->info->masks;
 
 	/* enable broadcast storm limit */
-	ksz_port_cfg(dev, port, P_BCAST_STORM_CTRL, PORT_BROADCAST_STORM, true);
+	offset = P_BCAST_STORM_CTRL;
+	if (ksz_is_ksz8463(dev))
+		offset = P1CR1;
+	ksz_port_cfg(dev, port, offset, PORT_BROADCAST_STORM, true);
 
 	ksz8_port_queue_split(dev, port, dev->info->num_tx_queues);
 
 	/* replace priority */
-	ksz_port_cfg(dev, port, P_802_1P_CTRL,
+	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)
@@ -1905,7 +1941,7 @@ 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_ksz88x3(dev) && !ksz_is_ksz8463(dev))
 		ksz_cfg(dev, REG_SW_CTRL_19, SW_INS_TAG_ENABLE, true);
 
 	for (i = 0; i < (dev->info->num_vlans / 4); i++)
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 5261747b7753..b78017abf0b8 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -2951,6 +2951,7 @@ static int ksz_parse_drive_strength(struct ksz_device *dev);
 static int ksz_setup(struct dsa_switch *ds)
 {
 	struct ksz_device *dev = ds->priv;
+	u16 storm_mask, storm_rate;
 	struct dsa_port *dp;
 	struct ksz_port *p;
 	const u16 *regs;
@@ -2980,10 +2981,15 @@ static int ksz_setup(struct dsa_switch *ds)
 	}
 
 	/* set broadcast storm protection 10% rate */
-	regmap_update_bits(ksz_regmap_16(dev), regs[S_BROADCAST_CTRL],
-			   BROADCAST_STORM_RATE,
-			   (BROADCAST_STORM_VALUE *
-			   BROADCAST_STORM_PROT_RATE) / 100);
+	storm_mask = BROADCAST_STORM_RATE;
+	storm_rate = (BROADCAST_STORM_VALUE * BROADCAST_STORM_PROT_RATE) / 100;
+	if (ksz_is_ksz8463(dev)) {
+		storm_mask = swab16(storm_mask);
+		storm_rate = swab16(storm_rate);
+	}
+	regmap_update_bits(ksz_regmap_16(dev),
+			   reg16(dev, regs[S_BROADCAST_CTRL]),
+			   storm_mask, storm_rate);
 
 	dev->dev_ops->config_cpu_port(ds);
 
@@ -4222,6 +4228,17 @@ static int ksz_ets_band_to_queue(struct tc_ets_qopt_offload_replace_params *p,
 	return p->bands - 1 - band;
 }
 
+static u8 ksz8463_tc_ctrl(int port, int queue)
+{
+	u8 reg;
+
+	reg = 0xC8 + port * 4;
+	reg += ((3 - queue) / 2) * 2;
+	reg++;
+	reg -= (queue & 1);
+	return reg;
+}
+
 /**
  * ksz88x3_tc_ets_add - Configure ETS (Enhanced Transmission Selection)
  *                      for a port on KSZ88x3 switch
@@ -4257,6 +4274,8 @@ static int ksz88x3_tc_ets_add(struct ksz_device *dev, int port,
 		 * port/queue
 		 */
 		reg = KSZ8873_TXQ_SPLIT_CTRL_REG(port, queue);
+		if (ksz_is_ksz8463(dev))
+			reg = ksz8463_tc_ctrl(port, queue);
 
 		/* Clear WFQ enable bit to select strict priority scheduling */
 		ret = ksz_rmw8(dev, reg, KSZ8873_TXQ_WFQ_ENABLE, 0);
@@ -4292,6 +4311,8 @@ static int ksz88x3_tc_ets_del(struct ksz_device *dev, int port)
 		 * port/queue
 		 */
 		reg = KSZ8873_TXQ_SPLIT_CTRL_REG(port, queue);
+		if (ksz_is_ksz8463(dev))
+			reg = ksz8463_tc_ctrl(port, queue);
 
 		/* Set WFQ enable bit to revert back to default scheduling
 		 * mode
@@ -4439,7 +4460,7 @@ static int ksz_tc_setup_qdisc_ets(struct dsa_switch *ds, int port,
 	struct ksz_device *dev = ds->priv;
 	int ret;
 
-	if (is_ksz8(dev) && !ksz_is_ksz88x3(dev))
+	if (is_ksz8(dev) && !(ksz_is_ksz88x3(dev) || ksz_is_ksz8463(dev)))
 		return -EOPNOTSUPP;
 
 	if (qopt->parent != TC_H_ROOT) {
@@ -4453,13 +4474,13 @@ static int ksz_tc_setup_qdisc_ets(struct dsa_switch *ds, int port,
 		if (ret)
 			return ret;
 
-		if (ksz_is_ksz88x3(dev))
+		if (ksz_is_ksz88x3(dev) || ksz_is_ksz8463(dev))
 			return ksz88x3_tc_ets_add(dev, port,
 						  &qopt->replace_params);
 		else
 			return ksz_tc_ets_add(dev, port, &qopt->replace_params);
 	case TC_ETS_DESTROY:
-		if (ksz_is_ksz88x3(dev))
+		if (ksz_is_ksz88x3(dev) || ksz_is_ksz8463(dev))
 			return ksz88x3_tc_ets_del(dev, port);
 		else
 			return ksz_tc_ets_del(dev, port);
diff --git a/drivers/net/dsa/microchip/ksz_dcb.c b/drivers/net/dsa/microchip/ksz_dcb.c
index c3b501997ac9..7131c5caac54 100644
--- a/drivers/net/dsa/microchip/ksz_dcb.c
+++ b/drivers/net/dsa/microchip/ksz_dcb.c
@@ -16,10 +16,12 @@
  * Therefore, we define the base offset as 0x00 here to align with that logic.
  */
 #define KSZ8_REG_PORT_1_CTRL_0			0x00
+#define KSZ8463_REG_PORT_1_CTRL_0		0x6C
 #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 KSZ8463_REG_TOS_DSCP_CTRL		0x16
 #define KSZ88X3_REG_TOS_DSCP_CTRL		0x60
 #define KSZ8765_REG_TOS_DSCP_CTRL		0x90
 
@@ -98,6 +100,8 @@ static void ksz_get_default_port_prio_reg(struct ksz_device *dev, int *reg,
 		*reg = KSZ8_REG_PORT_1_CTRL_0;
 		*mask = KSZ8_PORT_BASED_PRIO_M;
 		*shift = __bf_shf(KSZ8_PORT_BASED_PRIO_M);
+		if (ksz_is_ksz8463(dev))
+			*reg = KSZ8463_REG_PORT_1_CTRL_0;
 	} else {
 		*reg = KSZ9477_REG_PORT_MRI_MAC_CTRL;
 		*mask = KSZ9477_PORT_BASED_PRIO_M;
@@ -122,10 +126,12 @@ static void ksz_get_dscp_prio_reg(struct ksz_device *dev, int *reg,
 		*reg = KSZ8765_REG_TOS_DSCP_CTRL;
 		*per_reg = 4;
 		*mask = GENMASK(1, 0);
-	} else if (ksz_is_ksz88x3(dev)) {
+	} else if (ksz_is_ksz88x3(dev) || ksz_is_ksz8463(dev)) {
 		*reg = KSZ88X3_REG_TOS_DSCP_CTRL;
 		*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;
@@ -151,6 +157,8 @@ static void ksz_get_apptrust_map_and_reg(struct ksz_device *dev,
 		*map = ksz8_apptrust_map_to_bit;
 		*reg = KSZ8_REG_PORT_1_CTRL_0;
 		*mask = KSZ8_PORT_DIFFSERV_ENABLE | KSZ8_PORT_802_1P_ENABLE;
+		if (ksz_is_ksz8463(dev))
+			*reg = KSZ8463_REG_PORT_1_CTRL_0;
 	} else {
 		*map = ksz9477_apptrust_map_to_bit;
 		*reg = KSZ9477_REG_PORT_MRI_PRIO_CTRL;
-- 
2.34.1

On Fri, Jul 18, 2025 at 06:21:03PM -0700, Tristram.Ha@microchip.com wrote:
> From: Tristram Ha <tristram.ha@microchip.com>
> 
> KSZ8463 does not use same set of registers as KSZ8863 so it is necessary
> to change some registers when using KSZ8463.
> 
> Signed-off-by: Tristram Ha <tristram.ha@microchip.com>
> ---
> v3
> - Replace cpu_to_be16() with swab16() to avoid compiler warning

...

> diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c

...

> @@ -2980,10 +2981,15 @@ static int ksz_setup(struct dsa_switch *ds)
>  	}
>  
>  	/* set broadcast storm protection 10% rate */
> -	regmap_update_bits(ksz_regmap_16(dev), regs[S_BROADCAST_CTRL],
> -			   BROADCAST_STORM_RATE,
> -			   (BROADCAST_STORM_VALUE *
> -			   BROADCAST_STORM_PROT_RATE) / 100);
> +	storm_mask = BROADCAST_STORM_RATE;
> +	storm_rate = (BROADCAST_STORM_VALUE * BROADCAST_STORM_PROT_RATE) / 100;
> +	if (ksz_is_ksz8463(dev)) {
> +		storm_mask = swab16(storm_mask);
> +		storm_rate = swab16(storm_rate);
> +	}
> +	regmap_update_bits(ksz_regmap_16(dev),
> +			   reg16(dev, regs[S_BROADCAST_CTRL]),
> +			   storm_mask, storm_rate);

Hi Tristram,

I am confused by the use of swab16() here.

Let us say that we are running on a little endian host (likely).
Then the effect of this is to pass big endian values to regmap_update_bits().

But if we are running on a big endian host, the opposite will be true:
little endian values will be passed to regmap_update_bits().


Looking at KSZ_REGMAP_ENTRY() I see:

#define KSZ_REGMAP_ENTRY(width, swp, regbits, regpad, regalign)         \
        {                                                               \
		...
                .reg_format_endian = REGMAP_ENDIAN_BIG,                 \
                .val_format_endian = REGMAP_ENDIAN_BIG                  \
        }

Which based on a skimming the regmap code implies to me that
regmap_update_bits() should be passed host byte order values
which regmap will convert to big endian when writing out
these values.

It is unclear to me why changing the byte order of storm_mask
and storm_rate is needed here. But it does seem clear that
it will lead to inconsistent results on big endian and little
endian hosts.

...

On Sun, Jul 20, 2025 at 11:17:03AM +0100, Simon Horman wrote:
> On Fri, Jul 18, 2025 at 06:21:03PM -0700, Tristram.Ha@microchip.com wrote:
> > From: Tristram Ha <tristram.ha@microchip.com>
> > 
> > KSZ8463 does not use same set of registers as KSZ8863 so it is necessary
> > to change some registers when using KSZ8463.
> > 
> > Signed-off-by: Tristram Ha <tristram.ha@microchip.com>
> > ---
> > v3
> > - Replace cpu_to_be16() with swab16() to avoid compiler warning
> 
> ...
> 
> > diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
> 
> ...
> 
> > @@ -2980,10 +2981,15 @@ static int ksz_setup(struct dsa_switch *ds)
> >  	}
> >  
> >  	/* set broadcast storm protection 10% rate */
> > -	regmap_update_bits(ksz_regmap_16(dev), regs[S_BROADCAST_CTRL],
> > -			   BROADCAST_STORM_RATE,
> > -			   (BROADCAST_STORM_VALUE *
> > -			   BROADCAST_STORM_PROT_RATE) / 100);
> > +	storm_mask = BROADCAST_STORM_RATE;
> > +	storm_rate = (BROADCAST_STORM_VALUE * BROADCAST_STORM_PROT_RATE) / 100;
> > +	if (ksz_is_ksz8463(dev)) {
> > +		storm_mask = swab16(storm_mask);
> > +		storm_rate = swab16(storm_rate);
> > +	}
> > +	regmap_update_bits(ksz_regmap_16(dev),
> > +			   reg16(dev, regs[S_BROADCAST_CTRL]),
> > +			   storm_mask, storm_rate);
> 
> Hi Tristram,
> 
> I am confused by the use of swab16() here.
> 
> Let us say that we are running on a little endian host (likely).
> Then the effect of this is to pass big endian values to regmap_update_bits().
> 
> But if we are running on a big endian host, the opposite will be true:
> little endian values will be passed to regmap_update_bits().
> 
> 
> Looking at KSZ_REGMAP_ENTRY() I see:
> 
> #define KSZ_REGMAP_ENTRY(width, swp, regbits, regpad, regalign)         \
>         {                                                               \
> 		...
>                 .reg_format_endian = REGMAP_ENDIAN_BIG,                 \
>                 .val_format_endian = REGMAP_ENDIAN_BIG                  \
>         }

Update; I now see this in another patch of the series:

+#define KSZ8463_REGMAP_ENTRY(width, swp, regbits, regpad, regalign)    \
+       {                                                               \
		...
+               .reg_format_endian = REGMAP_ENDIAN_BIG,                 \
+               .val_format_endian = REGMAP_ENDIAN_LITTLE               \
+       }

Which I understand to mean that the hardware is expecting little endian
values. But still, my concerns raised in my previous email of this
thread remain.

And I have a question: does this chip use little endian register values
whereas other chips used big endian register values?

> 
> Which based on a skimming the regmap code implies to me that
> regmap_update_bits() should be passed host byte order values
> which regmap will convert to big endian when writing out
> these values.
> 
> It is unclear to me why changing the byte order of storm_mask
> and storm_rate is needed here. But it does seem clear that
> it will lead to inconsistent results on big endian and little
> endian hosts.
> 
> ...
>