[PATCH v1 phy-next 0/8] RCW override for 10G Lynx dynamic protocol reconfiguration

[PATCH v1 phy-next 0/8] RCW override for 10G Lynx dynamic protocol reconfiguration

[Vladimir Oltean]

Previous set "New Generic PHY driver for Lynx 10G SerDes":
https://lore.kernel.org/linux-phy/20260610151952.2141019-1-vladimir.oltean@nxp.com/
introduced the 10G Lynx SerDes driver with a reduced functionality set.
Namely, only minor protocol changes are supported (1GbE <-> 2.5GbE).
The major protocol changes need a procedure named RCW override,
explained in more detail in commits 6/8 and 7/8.

To keep the ball roling, this series adds kernel and device tree binding
support for RCW override. (being so close to the merge window, I don't
really expect this series to be merged, just want to get an initial
feedback so I can keep working on it)

Two components are involved:
- drivers/soc/fsl/guts.c (binding is fsl,layerscape-dcfg.yaml) - Device
  Configuration Unit, this is API provider for the SerDes driver to
  request RCW override depending on SoC
- drivers/phy/freescale/phy-fsl-lynx-10g.c - SerDes PHY driver, this is
  API consumer

The guts driver probes on DCFG blocks from multiple Freescale SoC
generations:
- MPC85xx, BSC and QorIQ (PowerPC) are all covered by the
  Documentation/devicetree/bindings/soc/fsl/guts.txt schema
- Layerscape (Arm) is covered by
  Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml

It is ultimately the same hardware block, just that (from what I can
tell) the Layerscape nodes are also compatible with syscon, and PowerPC
aren't.

RCW override has only been validated on select Layerscape SoCs, so
converting guts.txt to a PowerPC schema is out of scope for this
series - we don't even touch that (just in case it gets asked).

Using syscon to map the DCFG_DCSR register block in the Lynx SerDes
driver instead of creating this guts <-> lynx API was considered, but
because the RCW procedure is SoC-specific, it was ruled out for
polluting the SerDes driver. The guts driver is all about SoC awareness
anyway, and it offers some abstraction of all the gory details.

Cc: Conor Dooley <conor@kernel.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc: Rob Herring <robh@kernel.org>

Ioana Ciornei (5):
  soc: fsl: guts: use a macro to encode the DCFG CCSR space
  soc: fsl: guts: add a global structure to hold state
  soc: fsl: guts: add a central fsl_guts_read() function
  soc: fsl: guts: make it easier to determine on which SoC we are
    running
  soc: fsl: guts: implement the RCW override procedure

Vladimir Oltean (3):
  soc: fsl: guts: make fsl_soc_data available after fsl_guts_init()
  dt-bindings: fsl: layerscape-dcfg: define DCFG_DCSR region
  phy: lynx-10g: use RCW override procedure for dynamic protocol change

 .../bindings/soc/fsl/fsl,layerscape-dcfg.yaml |  15 +-
 drivers/phy/freescale/Kconfig                 |   1 +
 drivers/phy/freescale/phy-fsl-lynx-10g.c      |  24 +-
 drivers/soc/fsl/guts.c                        | 370 ++++++++++++++++--
 include/linux/fsl/guts.h                      |  20 +-
 5 files changed, 394 insertions(+), 36 deletions(-)

-- 
2.34.1

[PATCH v1 phy-next 1/8] soc: fsl: guts: use a macro to encode the DCFG CCSR space

[Vladimir Oltean]

From: Ioana Ciornei <ioana.ciornei@nxp.com>

Instead of using a hardcoded value when iomapping the DCFG CCSR space,
add a new macro for it. The code will be easier to follow this way,
especially when we add support for the DCFG DCSR space as well.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 drivers/soc/fsl/guts.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/fsl/guts.c b/drivers/soc/fsl/guts.c
index 9bee7baec2b9..f87ee47c1503 100644
--- a/drivers/soc/fsl/guts.c
+++ b/drivers/soc/fsl/guts.c
@@ -14,6 +14,8 @@
 #include <linux/platform_device.h>
 #include <linux/fsl/guts.h>
 
+#define DCFG_CCSR	0
+
 struct fsl_soc_die_attr {
 	char	*die;
 	u32	svr;
@@ -197,7 +199,7 @@ static int __init fsl_guts_init(void)
 		return 0;
 	soc_data = match->data;
 
-	regs = of_iomap(np, 0);
+	regs = of_iomap(np, DCFG_CCSR);
 	if (!regs) {
 		of_node_put(np);
 		return -ENOMEM;
-- 
2.34.1

[PATCH v1 phy-next 2/8] soc: fsl: guts: add a global structure to hold state

[Vladimir Oltean]

From: Ioana Ciornei <ioana.ciornei@nxp.com>

Add the fsl_soc_guts structure in order to pass information like base
addresses, endianness etc between the init time and the runtime
operations (RCW override) which will get added in future patches.
There is no point in mapping and unmapping the DCFG CCSR space every
time we need to make a read, just map it once and keep its reference in
this new global struture.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 drivers/soc/fsl/guts.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/soc/fsl/guts.c b/drivers/soc/fsl/guts.c
index f87ee47c1503..a0a52a5603a5 100644
--- a/drivers/soc/fsl/guts.c
+++ b/drivers/soc/fsl/guts.c
@@ -106,6 +106,11 @@ static const struct fsl_soc_die_attr fsl_soc_die[] = {
 	{ },
 };
 
+static struct fsl_soc_guts {
+	struct ccsr_guts __iomem *dcfg_ccsr;
+	bool little_endian;
+} soc;
+
 static const struct fsl_soc_die_attr *fsl_soc_die_match(
 	u32 svr, const struct fsl_soc_die_attr *matches)
 {
@@ -187,9 +192,7 @@ static int __init fsl_guts_init(void)
 	const struct fsl_soc_die_attr *soc_die;
 	const struct fsl_soc_data *soc_data;
 	const struct of_device_id *match;
-	struct ccsr_guts __iomem *regs;
 	struct device_node *np;
-	bool little_endian;
 	u64 soc_uid = 0;
 	u32 svr;
 	int ret;
@@ -199,18 +202,17 @@ static int __init fsl_guts_init(void)
 		return 0;
 	soc_data = match->data;
 
-	regs = of_iomap(np, DCFG_CCSR);
-	if (!regs) {
+	soc.dcfg_ccsr = of_iomap(np, DCFG_CCSR);
+	if (!soc.dcfg_ccsr) {
 		of_node_put(np);
 		return -ENOMEM;
 	}
 
-	little_endian = of_property_read_bool(np, "little-endian");
-	if (little_endian)
-		svr = ioread32(&regs->svr);
+	soc.little_endian = of_property_read_bool(np, "little-endian");
+	if (soc.little_endian)
+		svr = ioread32(&soc.dcfg_ccsr->svr);
 	else
-		svr = ioread32be(&regs->svr);
-	iounmap(regs);
+		svr = ioread32be(&soc.dcfg_ccsr->svr);
 	of_node_put(np);
 
 	/* Register soc device */
@@ -263,6 +265,8 @@ static int __init fsl_guts_init(void)
 
 err_nomem:
 	ret = -ENOMEM;
+
+	iounmap(soc.dcfg_ccsr);
 err:
 	kfree(soc_dev_attr->family);
 	kfree(soc_dev_attr->soc_id);
-- 
2.34.1

[PATCH v1 phy-next 3/8] soc: fsl: guts: add a central fsl_guts_read() function

[Vladimir Oltean]

From: Ioana Ciornei <ioana.ciornei@nxp.com>

Add a central fsl_guts_read() function which will take into account the
endianness that was already determined. No point is duplicating the
if-else statement each time we need to read a DCFG register.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 drivers/soc/fsl/guts.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/soc/fsl/guts.c b/drivers/soc/fsl/guts.c
index a0a52a5603a5..dc1a42cd9544 100644
--- a/drivers/soc/fsl/guts.c
+++ b/drivers/soc/fsl/guts.c
@@ -111,6 +111,14 @@ static struct fsl_soc_guts {
 	bool little_endian;
 } soc;
 
+static unsigned int fsl_guts_read(const void __iomem *reg)
+{
+	if (soc.little_endian)
+		return ioread32(reg);
+
+	return ioread32be(reg);
+}
+
 static const struct fsl_soc_die_attr *fsl_soc_die_match(
 	u32 svr, const struct fsl_soc_die_attr *matches)
 {
@@ -209,10 +217,7 @@ static int __init fsl_guts_init(void)
 	}
 
 	soc.little_endian = of_property_read_bool(np, "little-endian");
-	if (soc.little_endian)
-		svr = ioread32(&soc.dcfg_ccsr->svr);
-	else
-		svr = ioread32be(&soc.dcfg_ccsr->svr);
+	svr = fsl_guts_read(&soc.dcfg_ccsr->svr);
 	of_node_put(np);
 
 	/* Register soc device */
-- 
2.34.1

[PATCH v1 phy-next 4/8] soc: fsl: guts: make it easier to determine on which SoC we are running

[Vladimir Oltean]

From: Ioana Ciornei <ioana.ciornei@nxp.com>

The guts driver will need to easily determine on which SoC it's running
when it will need to perform RCW override at runtime. The guts driver
knows this already because fsl_guts_init() reads the QorIQ/Layerscape
architectural System Version Register (SVR), but it doesn't save this
for later lookups.

Add a new qoriq_die enum to be used as an index in the fsl_soc_die
array. A new fsl_soc_die_match_one() function is also added so that we
can directly determine if the SVR is a match with a specific die.
The SVR value read from the DCFG CCSR is also kept in the global soc
structure so that it can be accessed when needed.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 drivers/soc/fsl/guts.c | 47 ++++++++++++++++++++++++++++++++++++------
 1 file changed, 41 insertions(+), 6 deletions(-)

diff --git a/drivers/soc/fsl/guts.c b/drivers/soc/fsl/guts.c
index dc1a42cd9544..1494b545bbb4 100644
--- a/drivers/soc/fsl/guts.c
+++ b/drivers/soc/fsl/guts.c
@@ -27,6 +27,23 @@ struct fsl_soc_data {
 	u32 uid_offset;
 };
 
+enum qoriq_die {
+	DIE_T4240,
+	DIE_T1040,
+	DIE_T2080,
+	DIE_T1024,
+	DIE_LS1043A,
+	DIE_LS2080A,
+	DIE_LS1088A,
+	DIE_LS1012A,
+	DIE_LS1046A,
+	DIE_LS2088A,
+	DIE_LS1021A,
+	DIE_LX2160A,
+	DIE_LS1028A,
+	DIE_MAX,
+};
+
 /* SoC die attribute definition for QorIQ platform */
 static const struct fsl_soc_die_attr fsl_soc_die[] = {
 	/*
@@ -34,21 +51,25 @@ static const struct fsl_soc_die_attr fsl_soc_die[] = {
 	 */
 
 	/* Die: T4240, SoC: T4240/T4160/T4080 */
+	[DIE_T4240] =
 	{ .die		= "T4240",
 	  .svr		= 0x82400000,
 	  .mask		= 0xfff00000,
 	},
 	/* Die: T1040, SoC: T1040/T1020/T1042/T1022 */
+	[DIE_T1040] =
 	{ .die		= "T1040",
 	  .svr		= 0x85200000,
 	  .mask		= 0xfff00000,
 	},
 	/* Die: T2080, SoC: T2080/T2081 */
+	[DIE_T2080] =
 	{ .die		= "T2080",
 	  .svr		= 0x85300000,
 	  .mask		= 0xfff00000,
 	},
 	/* Die: T1024, SoC: T1024/T1014/T1023/T1013 */
+	[DIE_T1024] =
 	{ .die		= "T1024",
 	  .svr		= 0x85400000,
 	  .mask		= 0xfff00000,
@@ -59,46 +80,55 @@ static const struct fsl_soc_die_attr fsl_soc_die[] = {
 	 */
 
 	/* Die: LS1043A, SoC: LS1043A/LS1023A */
+	[DIE_LS1043A] =
 	{ .die		= "LS1043A",
 	  .svr		= 0x87920000,
 	  .mask		= 0xffff0000,
 	},
 	/* Die: LS2080A, SoC: LS2080A/LS2040A/LS2085A */
+	[DIE_LS2080A] =
 	{ .die		= "LS2080A",
 	  .svr		= 0x87010000,
 	  .mask		= 0xff3f0000,
 	},
 	/* Die: LS1088A, SoC: LS1088A/LS1048A/LS1084A/LS1044A */
+	[DIE_LS1088A] =
 	{ .die		= "LS1088A",
 	  .svr		= 0x87030000,
 	  .mask		= 0xff3f0000,
 	},
 	/* Die: LS1012A, SoC: LS1012A */
+	[DIE_LS1012A] =
 	{ .die		= "LS1012A",
 	  .svr		= 0x87040000,
 	  .mask		= 0xffff0000,
 	},
 	/* Die: LS1046A, SoC: LS1046A/LS1026A */
+	[DIE_LS1046A] =
 	{ .die		= "LS1046A",
 	  .svr		= 0x87070000,
 	  .mask		= 0xffff0000,
 	},
 	/* Die: LS2088A, SoC: LS2088A/LS2048A/LS2084A/LS2044A */
+	[DIE_LS2088A] =
 	{ .die		= "LS2088A",
 	  .svr		= 0x87090000,
 	  .mask		= 0xff3f0000,
 	},
 	/* Die: LS1021A, SoC: LS1021A/LS1020A/LS1022A */
+	[DIE_LS1021A] =
 	{ .die		= "LS1021A",
 	  .svr		= 0x87000000,
 	  .mask		= 0xfff70000,
 	},
 	/* Die: LX2160A, SoC: LX2160A/LX2120A/LX2080A */
+	[DIE_LX2160A] =
 	{ .die          = "LX2160A",
 	  .svr          = 0x87360000,
 	  .mask         = 0xff3f0000,
 	},
 	/* Die: LS1028A, SoC: LS1028A */
+	[DIE_LS1028A] =
 	{ .die          = "LS1028A",
 	  .svr          = 0x870b0000,
 	  .mask         = 0xff3f0000,
@@ -109,6 +139,7 @@ static const struct fsl_soc_die_attr fsl_soc_die[] = {
 static struct fsl_soc_guts {
 	struct ccsr_guts __iomem *dcfg_ccsr;
 	bool little_endian;
+	u32 svr;
 } soc;
 
 static unsigned int fsl_guts_read(const void __iomem *reg)
@@ -119,11 +150,16 @@ static unsigned int fsl_guts_read(const void __iomem *reg)
 	return ioread32be(reg);
 }
 
+static bool fsl_soc_die_match_one(u32 svr, const struct fsl_soc_die_attr *match)
+{
+	return match->svr == (svr & match->mask);
+}
+
 static const struct fsl_soc_die_attr *fsl_soc_die_match(
 	u32 svr, const struct fsl_soc_die_attr *matches)
 {
 	while (matches->svr) {
-		if (matches->svr == (svr & matches->mask))
+		if (fsl_soc_die_match_one(svr, matches))
 			return matches;
 		matches++;
 	}
@@ -202,7 +238,6 @@ static int __init fsl_guts_init(void)
 	const struct of_device_id *match;
 	struct device_node *np;
 	u64 soc_uid = 0;
-	u32 svr;
 	int ret;
 
 	np = of_find_matching_node_and_match(NULL, fsl_guts_of_match, &match);
@@ -217,7 +252,7 @@ static int __init fsl_guts_init(void)
 	}
 
 	soc.little_endian = of_property_read_bool(np, "little-endian");
-	svr = fsl_guts_read(&soc.dcfg_ccsr->svr);
+	soc.svr = fsl_guts_read(&soc.dcfg_ccsr->svr);
 	of_node_put(np);
 
 	/* Register soc device */
@@ -229,7 +264,7 @@ static int __init fsl_guts_init(void)
 	if (ret)
 		of_machine_read_compatible(&soc_dev_attr->machine, 0);
 
-	soc_die = fsl_soc_die_match(svr, fsl_soc_die);
+	soc_die = fsl_soc_die_match(soc.svr, fsl_soc_die);
 	if (soc_die) {
 		soc_dev_attr->family = kasprintf(GFP_KERNEL, "QorIQ %s",
 						 soc_die->die);
@@ -239,12 +274,12 @@ static int __init fsl_guts_init(void)
 	if (!soc_dev_attr->family)
 		goto err_nomem;
 
-	soc_dev_attr->soc_id = kasprintf(GFP_KERNEL, "svr:0x%08x", svr);
+	soc_dev_attr->soc_id = kasprintf(GFP_KERNEL, "svr:0x%08x", soc.svr);
 	if (!soc_dev_attr->soc_id)
 		goto err_nomem;
 
 	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%d.%d",
-					   (svr >>  4) & 0xf, svr & 0xf);
+					   (soc.svr >>  4) & 0xf, soc.svr & 0xf);
 	if (!soc_dev_attr->revision)
 		goto err_nomem;
 
-- 
2.34.1

[PATCH v1 phy-next 5/8] soc: fsl: guts: make fsl_soc_data available after fsl_guts_init()

[Vladimir Oltean]

In a future change, struct fsl_soc_data will be extended with methods
for performing RCW override.

Since this will be performed from a calling context outside
fsl_guts_init(), we need to keep track of the soc_data that we determine
at fsl_guts_init() time, so we can reference it later.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 drivers/soc/fsl/guts.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/soc/fsl/guts.c b/drivers/soc/fsl/guts.c
index 1494b545bbb4..9f2aff07a274 100644
--- a/drivers/soc/fsl/guts.c
+++ b/drivers/soc/fsl/guts.c
@@ -138,6 +138,7 @@ static const struct fsl_soc_die_attr fsl_soc_die[] = {
 
 static struct fsl_soc_guts {
 	struct ccsr_guts __iomem *dcfg_ccsr;
+	const struct fsl_soc_data *data;
 	bool little_endian;
 	u32 svr;
 } soc;
@@ -234,7 +235,6 @@ static int __init fsl_guts_init(void)
 	struct soc_device_attribute *soc_dev_attr;
 	static struct soc_device *soc_dev;
 	const struct fsl_soc_die_attr *soc_die;
-	const struct fsl_soc_data *soc_data;
 	const struct of_device_id *match;
 	struct device_node *np;
 	u64 soc_uid = 0;
@@ -243,7 +243,7 @@ static int __init fsl_guts_init(void)
 	np = of_find_matching_node_and_match(NULL, fsl_guts_of_match, &match);
 	if (!np)
 		return 0;
-	soc_data = match->data;
+	soc.data = match->data;
 
 	soc.dcfg_ccsr = of_iomap(np, DCFG_CCSR);
 	if (!soc.dcfg_ccsr) {
@@ -283,9 +283,9 @@ static int __init fsl_guts_init(void)
 	if (!soc_dev_attr->revision)
 		goto err_nomem;
 
-	if (soc_data)
-		soc_uid = fsl_guts_get_soc_uid(soc_data->sfp_compat,
-					       soc_data->uid_offset);
+	if (soc.data)
+		soc_uid = fsl_guts_get_soc_uid(soc.data->sfp_compat,
+					       soc.data->uid_offset);
 	if (soc_uid)
 		soc_dev_attr->serial_number = kasprintf(GFP_KERNEL, "%016llX",
 							soc_uid);
-- 
2.34.1

[PATCH v1 phy-next 6/8] dt-bindings: fsl: layerscape-dcfg: define DCFG_DCSR region

[Vladimir Oltean]

In Layerscape (Arm) and QorIQ (PowerPC) devices, hardware peripherals
are accessed by the CPU through a portion of the SoC address space
called CCSR ("Configuration, Control, and Status Registers"). All
hardware IP blocks have their registers mapped here, and the Device
Configuration block makes no exception.

However, there exists a secondary range of the address space named DCSR
("Debug Control and Status Registers") which, like CCSR, also holds
registers of hardware IP blocks, except the DCSR contents is hidden in
all public reference manuals.

The intention of the CCSR/DCSR split, to the best of my knowledge, was
to place the functionality that is too low level for normal use, and
which is necessary only for debug, in a completely separate address
space which can be hidden.

A use case has appeared where networking SerDes lanes need to be
reconfigured at runtime for a different protocol (example: 10GBase-R to
SGMII), and the architecture of the SoCs does not normally permit that.
The Reset Configuration Word (RCW) is a data structure read by the SoC
preboot loader (PBL) which contains stuff like pinmuxing and SerDes
protocol mapping for each lane.

The RCW that the PBL has loaded is visible in the DCFG block's normal
status registers (from CCSR), as read only. Turns out, the RCW is also
mapped in the DCFG's shadow register map (in DCSR), in a write-only
form. Writing to the RCW registers from the DCFG's DCSR space to change
what the PBL has loaded is called "RCW override".

It has been validated that the RCW override procedure is necessary to
reconfigure the networking data path when a SerDes lane performs a major
protocol change. It changes some internal muxes which connect the PCS to
either the 10G MAC or to the 1G MAC.

Defining the DCSR area of the DCFG as a secondary 'reg' array element
allows operating systems to perform RCW overrides. Since it is
introduced late in the binding's lifetime, it is optional. It can be
identified by name, but also by index (first 'reg' is CCSR).

Note that while all SoCs should have a DCFG register block in DCSR, we
only need to expose it for the SoCs where the RCW override procedure is
known to be needed and has been validated.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
Cc: Conor Dooley <conor@kernel.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
---
 .../bindings/soc/fsl/fsl,layerscape-dcfg.yaml     | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml b/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml
index 3fb0534ea597..fc14fd0bf84b 100644
--- a/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml
+++ b/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml
@@ -36,7 +36,20 @@ properties:
           - const: simple-mfd
 
   reg:
-    maxItems: 1
+    minItems: 1
+    items:
+      - description:
+          Customer-visible DCFG register map from CCSR address space
+          (Configuration, Control and Status Registers)
+      - description:
+          Customer-hidden DCFG register map from DCSR address space
+          (Debug Control and Status Registers)
+
+  reg-names:
+    minItems: 1
+    items:
+      - const: dcfg_ccsr
+      - const: dcfg_dcsr
 
   little-endian: true
   big-endian: true
-- 
2.34.1

[PATCH v1 phy-next 7/8] soc: fsl: guts: implement the RCW override procedure

[Vladimir Oltean]

From: Ioana Ciornei <ioana.ciornei@nxp.com>

Add support for the RCW override procedure which enables runtime
reconfiguration of the protocol running on a SerDes lane. The procedure
is done through the DCFG DCSR space which now can be defined as the
second memory region of the guts DT node.
Support is added on the following SoCs: LS1046A, LS1088A, LS2088A.

The procedure is exported to the "client" driver - the Lynx10G SerDes
PHY driver - through the following functions:
- fsl_guts_lane_init() used to notify the initial / boot time lane mode
  running on a SerDes lane.
- fsl_guts_lane_validate() used to validate that changing the protocol
  on a specific lane is supported.
- fsl_guts_lane_set_mode() which can be used to request the RCW
  procedure be executed for a specific lane.

Since the RCW override procedure is different depending on the SoC, the
private fsl_soc_data structure is updated with two new per SoC callbacks
(.serdes_get_rcw_override() and .serdes_init_rcwcr()) which get used
from the generic fsl_guts_lane_set_mode() function. These two callbacks
hide all the SoC specific register offsets, masks and values so that the
_set_mode() procedure is straightforward.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
Cc: Conor Dooley <conor@kernel.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
---
 drivers/soc/fsl/guts.c   | 286 ++++++++++++++++++++++++++++++++++++++-
 include/linux/fsl/guts.h |  20 ++-
 2 files changed, 299 insertions(+), 7 deletions(-)

diff --git a/drivers/soc/fsl/guts.c b/drivers/soc/fsl/guts.c
index 9f2aff07a274..23ec5750080c 100644
--- a/drivers/soc/fsl/guts.c
+++ b/drivers/soc/fsl/guts.c
@@ -15,6 +15,30 @@
 #include <linux/fsl/guts.h>
 
 #define DCFG_CCSR	0
+#define DCFG_DCSR	1
+
+#define MAX_NUM_LANES	8
+#define MAX_NUM_SERDES	2
+
+#define LS1088A_RCWSR29_SRDS_PRTCL_S1_LNn(lane)	\
+	GENMASK(19 + 4 * (3 - lane), 16 + 4 * (3 - lane))
+#define LS1088A_RCWSR30_SRDS_PRTCL_S2_LNn(lane)	\
+	GENMASK(3 + 4 * (3 - lane), 4 * (3 - lane))
+
+#define LS1046A_RCWSR5_SRDS_PRTCL_S1(lane)	\
+	GENMASK(19 + 4 * (lane), 16 + 4 * (lane))
+#define SRDS_PRTCL_NONE					0
+#define SRDS_PRTCL_XFI					1
+#define SRDS_PRTCL_2500BASEX				2
+#define SRDS_PRTCL_100BASEX_SGMII			3
+#define SRDS_PRTCL_QSGMII				4
+#define SRDS_PRTCL_PCIE					5
+
+#define LS2088A_RCWSR30_SRDS_CLK_EN_SEL_XGMII_S1	BIT(14)
+#define LS2088A_RCWSR30_SRDS_CLK_SEL_XGMII_Ln_S1(lane)	BIT(6 + (7 - (lane)))
+#define LS2088A_RCWSR30_SRDS_CLK_SEL_MSK		GENMASK(13, 6)
+#define SRDS_CLK_SEL_XGMII				1
+#define SRDS_CLK_SEL_GMII				0
 
 struct fsl_soc_die_attr {
 	char	*die;
@@ -22,9 +46,19 @@ struct fsl_soc_die_attr {
 	u32	mask;
 };
 
+struct fsl_soc_serdes_rcw_override {
+	int offset;
+	int mask;
+	int val;
+};
+
 struct fsl_soc_data {
 	const char *sfp_compat;
 	u32 uid_offset;
+	int (*serdes_get_rcw_override)(int index, int lane,
+				       enum lynx_lane_mode lane_mode,
+				       struct fsl_soc_serdes_rcw_override *override);
+	void (*serdes_init_rcwcr)(int index);
 };
 
 enum qoriq_die {
@@ -138,9 +172,13 @@ static const struct fsl_soc_die_attr fsl_soc_die[] = {
 
 static struct fsl_soc_guts {
 	struct ccsr_guts __iomem *dcfg_ccsr;
+	struct ccsr_guts __iomem *dcfg_dcsr;
 	const struct fsl_soc_data *data;
 	bool little_endian;
 	u32 svr;
+	enum lynx_lane_mode lane_mode[MAX_NUM_SERDES][MAX_NUM_LANES];
+	bool rcwcr_init_done;
+	spinlock_t rcwcr_lock; /* serializes concurrent writes to the RCWCR */
 } soc;
 
 static unsigned int fsl_guts_read(const void __iomem *reg)
@@ -151,6 +189,28 @@ static unsigned int fsl_guts_read(const void __iomem *reg)
 	return ioread32be(reg);
 }
 
+static void fsl_guts_write(void __iomem *reg, u32 val)
+{
+	if (soc.little_endian)
+		iowrite32(val, reg);
+	else
+		iowrite32be(val, reg);
+}
+
+/* Some fields of the Reset Configuration Word (RCW) can be overridden at
+ * runtime by writing to the RCWCRn registers contained within the DCSR space
+ * of the Device Configuration (DCFG) block. The layout of the RCWCRn registers
+ * is identical with the read-only RCWSRn from the CCSR space.
+ */
+static void fsl_guts_rmw(int offset, u32 val, u32 mask)
+{
+	u32 tmp = fsl_guts_read(&soc.dcfg_ccsr->rcwsr[offset]);
+
+	tmp &= ~mask;
+	tmp |= val;
+	fsl_guts_write(&soc.dcfg_dcsr->rcwcr[offset], tmp);
+}
+
 static bool fsl_soc_die_match_one(u32 svr, const struct fsl_soc_die_attr *match)
 {
 	return match->svr == (svr & match->mask);
@@ -167,6 +227,97 @@ static const struct fsl_soc_die_attr *fsl_soc_die_match(
 	return NULL;
 }
 
+static int
+fsl_guts_serdes_get_rcw_override(int serdes_idx, int lane,
+				 enum lynx_lane_mode lane_mode,
+				 struct fsl_soc_serdes_rcw_override *override)
+{
+	if ((!fsl_soc_die_match_one(soc.svr, &fsl_soc_die[DIE_LS1088A]) &&
+	     !fsl_soc_die_match_one(soc.svr, &fsl_soc_die[DIE_LS2088A]) &&
+	     !fsl_soc_die_match_one(soc.svr, &fsl_soc_die[DIE_LS1046A])) ||
+	    !soc.data || !soc.data->serdes_get_rcw_override) {
+		pr_debug("RCW override not implemented for SoC\n");
+		return -EINVAL;
+	}
+
+	if (!soc.dcfg_dcsr) {
+		pr_debug("Device tree does not define DCFG_DCSR region necessary for RCW override\n");
+		return -EINVAL;
+	}
+
+	return soc.data->serdes_get_rcw_override(serdes_idx, lane, lane_mode,
+						 override);
+}
+
+/**
+ * fsl_guts_lane_init() - Notify guts module of SerDes lane configuration
+ * @serdes_idx: zero-based SerDes block index
+ * @lane: zero-based lane index within SerDes
+ * @lane_mode: initial / boot time SerDes protocol for lane
+ *
+ * On the LS208xA SoC, the RCW override procedure needs to be aware of all link
+ * modes which are configured on a SerDes block.
+ */
+void fsl_guts_lane_init(int serdes_idx, int lane, enum lynx_lane_mode lane_mode)
+{
+	soc.lane_mode[serdes_idx - 1][lane] = lane_mode;
+}
+EXPORT_SYMBOL_NS_GPL(fsl_guts_lane_init, "FSL_GUTS");
+
+/**
+ * fsl_guts_lane_validate() - Validate that SerDes protocol is implemented and
+ *	supported on current SoC
+ * @serdes_idx: zero-based SerDes block index
+ * @lane: zero-based lane index within SerDes
+ * @lane_mode: requested SerDes protocol
+ *
+ * Should be called before actually requesting the RCW override procedure to be
+ * applied using %fsl_guts_lane_set_mode()
+ *
+ * Return: 0 if RCW override to protocol is possible, negative error otherwise
+ */
+int fsl_guts_lane_validate(int serdes_idx, int lane, enum lynx_lane_mode lane_mode)
+{
+	struct fsl_soc_serdes_rcw_override override;
+
+	return fsl_guts_serdes_get_rcw_override(serdes_idx, lane, lane_mode,
+						&override);
+}
+EXPORT_SYMBOL_NS_GPL(fsl_guts_lane_validate, "FSL_GUTS");
+
+/**
+ * fsl_guts_lane_set_mode() - apply RCW override procedure for SerDes lane
+ * @serdes_idx: zero-based SerDes block index
+ * @lane: zero-based lane index within SerDes
+ * @lane_mode: requested SerDes protocol
+ *
+ * Return: 0 on success, negative error otherwise
+ */
+int fsl_guts_lane_set_mode(int serdes_idx, int lane, enum lynx_lane_mode lane_mode)
+{
+	struct fsl_soc_serdes_rcw_override override;
+	int err;
+
+	err = fsl_guts_serdes_get_rcw_override(serdes_idx, lane, lane_mode,
+					       &override);
+	if (err)
+		return err;
+
+	spin_lock(&soc.rcwcr_lock);
+
+	if (soc.data->serdes_init_rcwcr)
+		soc.data->serdes_init_rcwcr(serdes_idx);
+
+	fsl_guts_rmw(override.offset, override.val << __bf_shf(override.mask),
+		     override.mask);
+	soc.lane_mode[serdes_idx - 1][lane] = lane_mode;
+
+	spin_unlock(&soc.rcwcr_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(fsl_guts_lane_set_mode, "FSL_GUTS");
+
 static u64 fsl_guts_get_soc_uid(const char *compat, unsigned int offset)
 {
 	struct device_node *np;
@@ -193,6 +344,128 @@ static u64 fsl_guts_get_soc_uid(const char *compat, unsigned int offset)
 	return uid;
 }
 
+static int ls1088a_serdes_get_rcw_override(int index, int lane,
+					   enum lynx_lane_mode lane_mode,
+					   struct fsl_soc_serdes_rcw_override *override)
+{
+	/* The RCW override procedure has to write to different registers
+	 * depending on the SerDes block index.
+	 */
+	switch (index) {
+	case 1:
+		override->offset = 28;
+		override->mask = LS1088A_RCWSR29_SRDS_PRTCL_S1_LNn(lane);
+		break;
+	case 2:
+		override->offset = 29;
+		override->mask = LS1088A_RCWSR30_SRDS_PRTCL_S2_LNn(lane);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (lynx_lane_mode_uses_xgmii_mac(lane_mode))
+		override->val = SRDS_PRTCL_XFI;
+	else if (lynx_lane_mode_uses_gmii_mac(lane_mode))
+		override->val = SRDS_PRTCL_100BASEX_SGMII;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ls1046a_serdes_get_rcw_override(int index, int lane,
+					   enum lynx_lane_mode lane_mode,
+					   struct fsl_soc_serdes_rcw_override *override)
+{
+	/* The RCW override procedure has to write to different registers
+	 * depending on the SerDes block index.
+	 */
+	switch (index) {
+	case 1:
+		override->offset = 4;
+		override->mask = LS1046A_RCWSR5_SRDS_PRTCL_S1(lane);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (lynx_lane_mode_uses_xgmii_mac(lane_mode))
+		override->val = SRDS_PRTCL_XFI;
+	else if (lynx_lane_mode_uses_gmii_mac(lane_mode))
+		override->val = SRDS_PRTCL_100BASEX_SGMII;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ls2088a_serdes_get_rcw_override(int index, int lane,
+					   enum lynx_lane_mode lane_mode,
+					   struct fsl_soc_serdes_rcw_override *override)
+{
+	switch (index) {
+	case 1:
+		override->offset = 29;
+		override->mask = LS2088A_RCWSR30_SRDS_CLK_SEL_XGMII_Ln_S1(lane);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (lynx_lane_mode_uses_xgmii_mac(lane_mode))
+		override->val = SRDS_CLK_SEL_XGMII;
+	else if (lynx_lane_mode_uses_gmii_mac(lane_mode))
+		override->val = SRDS_CLK_SEL_GMII;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+static void ls2088a_serdes_init_rcwcr(int serdes_idx)
+{
+	u32 reg;
+	int i;
+
+	if (serdes_idx != 1)
+		return;
+	if (soc.rcwcr_init_done)
+		return;
+
+	/* SRDS_CLK_EN_SEL_XGMII_S1: SerDes Clock Enable Select XGMII Serdes 1:
+	 * Enables to select GMII/XGMII clock according to
+	 * SRDS_CLK_SEL_XGMII_Ln_S1
+	 */
+	reg = LS2088A_RCWSR30_SRDS_CLK_EN_SEL_XGMII_S1;
+
+	/* We need to configure the initial state of all lanes for
+	 * the SerDes block #1
+	 */
+	for (i = 0; i < MAX_NUM_LANES; i++)
+		if (lynx_lane_mode_uses_xgmii_mac(soc.lane_mode[serdes_idx - 1][i]))
+			reg |= LS2088A_RCWSR30_SRDS_CLK_SEL_XGMII_Ln_S1(i);
+
+	fsl_guts_rmw(29, reg,
+		     LS2088A_RCWSR30_SRDS_CLK_EN_SEL_XGMII_S1 |
+		     LS2088A_RCWSR30_SRDS_CLK_SEL_MSK);
+
+	soc.rcwcr_init_done = true;
+}
+
+static const struct fsl_soc_data ls1088a_data = {
+	.serdes_get_rcw_override = ls1088a_serdes_get_rcw_override,
+};
+
+static const struct fsl_soc_data ls1046a_data = {
+	.serdes_get_rcw_override = ls1046a_serdes_get_rcw_override,
+};
+
+static const struct fsl_soc_data ls2088a_data = {
+	.serdes_get_rcw_override = ls2088a_serdes_get_rcw_override,
+	.serdes_init_rcwcr = ls2088a_serdes_init_rcwcr,
+};
+
 static const struct fsl_soc_data ls1028a_data = {
 	.sfp_compat = "fsl,ls1028a-sfp",
 	.uid_offset = 0x21c,
@@ -221,10 +494,10 @@ static const struct of_device_id fsl_guts_of_match[] = {
 	{ .compatible = "fsl,mpc8572-guts", },
 	{ .compatible = "fsl,ls1021a-dcfg", },
 	{ .compatible = "fsl,ls1043a-dcfg", },
-	{ .compatible = "fsl,ls2080a-dcfg", },
-	{ .compatible = "fsl,ls1088a-dcfg", },
+	{ .compatible = "fsl,ls2080a-dcfg", .data = &ls2088a_data},
+	{ .compatible = "fsl,ls1088a-dcfg", .data = &ls1088a_data},
 	{ .compatible = "fsl,ls1012a-dcfg", },
-	{ .compatible = "fsl,ls1046a-dcfg", },
+	{ .compatible = "fsl,ls1046a-dcfg", .data = &ls1046a_data},
 	{ .compatible = "fsl,lx2160a-dcfg", },
 	{ .compatible = "fsl,ls1028a-dcfg", .data = &ls1028a_data},
 	{}
@@ -250,6 +523,8 @@ static int __init fsl_guts_init(void)
 		of_node_put(np);
 		return -ENOMEM;
 	}
+	/* DCFG_DCSR is optional */
+	soc.dcfg_dcsr = of_iomap(np, DCFG_DCSR);
 
 	soc.little_endian = of_property_read_bool(np, "little-endian");
 	soc.svr = fsl_guts_read(&soc.dcfg_ccsr->svr);
@@ -296,6 +571,8 @@ static int __init fsl_guts_init(void)
 		goto err;
 	}
 
+	spin_lock_init(&soc.rcwcr_lock);
+
 	pr_info("Machine: %s\n", soc_dev_attr->machine);
 	pr_info("SoC family: %s\n", soc_dev_attr->family);
 	pr_info("SoC ID: %s, Revision: %s\n",
@@ -305,7 +582,8 @@ static int __init fsl_guts_init(void)
 
 err_nomem:
 	ret = -ENOMEM;
-
+	if (soc.dcfg_dcsr)
+		iounmap(soc.dcfg_dcsr);
 	iounmap(soc.dcfg_ccsr);
 err:
 	kfree(soc_dev_attr->family);
diff --git a/include/linux/fsl/guts.h b/include/linux/fsl/guts.h
index fdb55ca47a4f..176842531241 100644
--- a/include/linux/fsl/guts.h
+++ b/include/linux/fsl/guts.h
@@ -13,6 +13,7 @@
 
 #include <linux/types.h>
 #include <linux/io.h>
+#include <soc/fsl/phy-fsl-lynx.h>
 
 /*
  * Global Utility Registers.
@@ -91,9 +92,15 @@ struct ccsr_guts {
 	u32	iovselsr;	/* 0x.00c0 - I/O voltage select status register
 					     Called 'elbcvselcr' on 86xx SOCs */
 	u8	res0c4[0x100 - 0xc4];
-	u32	rcwsr[16];	/* 0x.0100 - Reset Control Word Status registers
-					     There are 16 registers */
-	u8	res140[0x224 - 0x140];
+	/* 0x.0100 - read-only Reset Configuration Word Status registers in
+	 * CCSR, or write-only Reset Configuration Word Control registers in
+	 * DCSR. In both cases there are 32 registers.
+	 */
+	union {
+		u32	rcwsr[32];
+		u32	rcwcr[32];
+	};
+	u8	res180[0x224 - 0x180];
 	u32	iodelay1;	/* 0x.0224 - IO delay control register 1 */
 	u32	iodelay2;	/* 0x.0228 - IO delay control register 2 */
 	u8	res22c[0x604 - 0x22c];
@@ -131,6 +138,13 @@ struct ccsr_guts {
 	u32	srds2cr1;	/* 0x.0f44 - SerDes2 Control Register 0 */
 } __attribute__ ((packed));
 
+void fsl_guts_lane_init(int serdes_idx, int lane,
+			enum lynx_lane_mode lane_mode);
+int fsl_guts_lane_validate(int serdes_idx, int lane,
+			   enum lynx_lane_mode lane_mode);
+int fsl_guts_lane_set_mode(int serdes_idx, int lane,
+			   enum lynx_lane_mode lane_mode);
+
 /* Alternate function signal multiplex control */
 #define MPC85xx_PMUXCR_QE(x) (0x8000 >> (x))
 
-- 
2.34.1

[PATCH v1 phy-next 8/8] phy: lynx-10g: use RCW override procedure for dynamic protocol change

[Vladimir Oltean]

Up until this patch, the only protocol change supported was between
1000Base-X/SGMII and 2500Base-X. The others require an RCW override
procedure which was lacking.

Since now the guts driver provides the means of applying this procedure,
make use of it and remove any comment which mentioned the limitation.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 drivers/phy/freescale/Kconfig            |  1 +
 drivers/phy/freescale/phy-fsl-lynx-10g.c | 24 +++++++++++++++---------
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/phy/freescale/Kconfig b/drivers/phy/freescale/Kconfig
index 5bf3864fbe64..d4e189fffbf8 100644
--- a/drivers/phy/freescale/Kconfig
+++ b/drivers/phy/freescale/Kconfig
@@ -58,6 +58,7 @@ config PHY_FSL_LYNX_10G
 	tristate "Freescale Layerscape Lynx 10G SerDes PHY support"
 	depends on OF
 	depends on ARCH_LAYERSCAPE || COMPILE_TEST
+	select FSL_GUTS
 	select GENERIC_PHY
 	select PHY_FSL_LYNX_CORE
 	help
diff --git a/drivers/phy/freescale/phy-fsl-lynx-10g.c b/drivers/phy/freescale/phy-fsl-lynx-10g.c
index 38def160ef1a..5ece7889aed7 100644
--- a/drivers/phy/freescale/phy-fsl-lynx-10g.c
+++ b/drivers/phy/freescale/phy-fsl-lynx-10g.c
@@ -8,6 +8,7 @@
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/workqueue.h>
+#include <linux/fsl/guts.h>
 
 #include "phy-fsl-lynx-core.h"
 
@@ -446,6 +447,7 @@ static void lynx_10g_lane_read_configuration(struct lynx_lane *lane)
 	}
 
 	lynx_10g_backup_pccr_val(lane);
+	fsl_guts_lane_init(priv->info->index, lane->id, lane->mode);
 }
 
 static int ls1028a_get_pccr(enum lynx_lane_mode lane_mode, int lane,
@@ -1167,14 +1169,7 @@ static bool lynx_10g_lane_mode_needs_rcw_override(struct lynx_lane *lane,
 
 	/* Major protocol changes, which involve changing the PCS connection to
 	 * the GMII MAC with the one to the XGMII MAC, require an RCW override
-	 * procedure to reconfigure an internal mux, as documented here:
-	 * https://lore.kernel.org/linux-phy/20230810102631.bvozjer3t67r67iy@skbuf/
-	 * This is SoC-specific, and not yet implemented in drivers/soc/fsl/guts.c.
-	 *
-	 * So the supported set of protocols depends on the initial lane mode.
-	 *
-	 * Minor protocol changes (SGMII <-> 1000Base-X <-> 2500Base-X or
-	 * 10GBase-R <-> USXGMII) are supported.
+	 * procedure to reconfigure an internal mux.
 	 */
 	if ((lynx_lane_mode_uses_gmii_mac(curr) &&
 	     lynx_lane_mode_uses_xgmii_mac(new)) ||
@@ -1189,6 +1184,7 @@ static int lynx_10g_validate(struct phy *phy, enum phy_mode mode, int submode,
 			     union phy_configure_opts *opts)
 {
 	struct lynx_lane *lane = phy_get_drvdata(phy);
+	struct lynx_priv *priv = lane->priv;
 	enum lynx_lane_mode lane_mode;
 	int err;
 
@@ -1197,7 +1193,8 @@ static int lynx_10g_validate(struct phy *phy, enum phy_mode mode, int submode,
 		return err;
 
 	if (lynx_10g_lane_mode_needs_rcw_override(lane, lane_mode))
-		return -EINVAL;
+		return fsl_guts_lane_validate(priv->info->index, lane->id,
+					      lane_mode);
 
 	return 0;
 }
@@ -1205,6 +1202,7 @@ static int lynx_10g_validate(struct phy *phy, enum phy_mode mode, int submode,
 static int lynx_10g_set_mode(struct phy *phy, enum phy_mode mode, int submode)
 {
 	struct lynx_lane *lane = phy_get_drvdata(phy);
+	struct lynx_priv *priv = lane->priv;
 	bool powered_up = lane->powered_up;
 	enum lynx_lane_mode lane_mode;
 	int err;
@@ -1225,6 +1223,13 @@ static int lynx_10g_set_mode(struct phy *phy, enum phy_mode mode, int submode)
 	if (powered_up)
 		lynx_10g_lane_halt(phy);
 
+	if (lynx_10g_lane_mode_needs_rcw_override(lane, lane_mode)) {
+		err = fsl_guts_lane_set_mode(priv->info->index, lane->id,
+					     lane_mode);
+		if (err)
+			goto out;
+	}
+
 	err = lynx_10g_lane_disable_pcvt(lane, lane->mode);
 	if (err)
 		goto out;
@@ -1314,6 +1319,7 @@ static struct platform_driver lynx_10g_driver = {
 };
 module_platform_driver(lynx_10g_driver);
 
+MODULE_IMPORT_NS("FSL_GUTS");
 MODULE_IMPORT_NS("PHY_FSL_LYNX");
 MODULE_AUTHOR("Ioana Ciornei <ioana.ciornei@nxp.com>");
 MODULE_AUTHOR("Vladimir Oltean <vladimir.oltean@nxp.com>");
-- 
2.34.1

Re: [PATCH v1 phy-next 6/8] dt-bindings: fsl: layerscape-dcfg: define DCFG_DCSR region

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 3952 bytes --]

On Thu, Jun 11, 2026 at 10:39:38PM +0300, Vladimir Oltean wrote:
> In Layerscape (Arm) and QorIQ (PowerPC) devices, hardware peripherals
> are accessed by the CPU through a portion of the SoC address space
> called CCSR ("Configuration, Control, and Status Registers"). All
> hardware IP blocks have their registers mapped here, and the Device
> Configuration block makes no exception.
> 
> However, there exists a secondary range of the address space named DCSR
> ("Debug Control and Status Registers") which, like CCSR, also holds
> registers of hardware IP blocks, except the DCSR contents is hidden in
> all public reference manuals.
> 
> The intention of the CCSR/DCSR split, to the best of my knowledge, was
> to place the functionality that is too low level for normal use, and
> which is necessary only for debug, in a completely separate address
> space which can be hidden.
> 
> A use case has appeared where networking SerDes lanes need to be
> reconfigured at runtime for a different protocol (example: 10GBase-R to
> SGMII), and the architecture of the SoCs does not normally permit that.
> The Reset Configuration Word (RCW) is a data structure read by the SoC
> preboot loader (PBL) which contains stuff like pinmuxing and SerDes
> protocol mapping for each lane.
> 
> The RCW that the PBL has loaded is visible in the DCFG block's normal
> status registers (from CCSR), as read only. Turns out, the RCW is also
> mapped in the DCFG's shadow register map (in DCSR), in a write-only
> form. Writing to the RCW registers from the DCFG's DCSR space to change
> what the PBL has loaded is called "RCW override".
> 
> It has been validated that the RCW override procedure is necessary to
> reconfigure the networking data path when a SerDes lane performs a major
> protocol change. It changes some internal muxes which connect the PCS to
> either the 10G MAC or to the 1G MAC.
> 
> Defining the DCSR area of the DCFG as a secondary 'reg' array element
> allows operating systems to perform RCW overrides. Since it is
> introduced late in the binding's lifetime, it is optional. It can be
> identified by name, but also by index (first 'reg' is CCSR).
> 
> Note that while all SoCs should have a DCFG register block in DCSR, we
> only need to expose it for the SoCs where the RCW override procedure is
> known to be needed and has been validated.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
> Cc: Conor Dooley <conor@kernel.org>

Where did this email come from btw? get_maintainer.pl result should have
+dt in it.
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
pw-bot: not-applicable

Cheers,
Conor.

> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  .../bindings/soc/fsl/fsl,layerscape-dcfg.yaml     | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml b/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml
> index 3fb0534ea597..fc14fd0bf84b 100644
> --- a/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml
> +++ b/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml
> @@ -36,7 +36,20 @@ properties:
>            - const: simple-mfd
>  
>    reg:
> -    maxItems: 1
> +    minItems: 1
> +    items:
> +      - description:
> +          Customer-visible DCFG register map from CCSR address space
> +          (Configuration, Control and Status Registers)
> +      - description:
> +          Customer-hidden DCFG register map from DCSR address space
> +          (Debug Control and Status Registers)
> +
> +  reg-names:
> +    minItems: 1
> +    items:
> +      - const: dcfg_ccsr
> +      - const: dcfg_dcsr
>  
>    little-endian: true
>    big-endian: true
> -- 
> 2.34.1
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

Re: [PATCH v1 phy-next 7/8] soc: fsl: guts: implement the RCW override procedure

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 15588 bytes --]

On Thu, Jun 11, 2026 at 10:39:39PM +0300, Vladimir Oltean wrote:
> From: Ioana Ciornei <ioana.ciornei@nxp.com>
> 
> Add support for the RCW override procedure which enables runtime
> reconfiguration of the protocol running on a SerDes lane. The procedure
> is done through the DCFG DCSR space which now can be defined as the
> second memory region of the guts DT node.
> Support is added on the following SoCs: LS1046A, LS1088A, LS2088A.
> 
> The procedure is exported to the "client" driver - the Lynx10G SerDes
> PHY driver - through the following functions:
> - fsl_guts_lane_init() used to notify the initial / boot time lane mode
>   running on a SerDes lane.
> - fsl_guts_lane_validate() used to validate that changing the protocol
>   on a specific lane is supported.
> - fsl_guts_lane_set_mode() which can be used to request the RCW
>   procedure be executed for a specific lane.
> 
> Since the RCW override procedure is different depending on the SoC, the
> private fsl_soc_data structure is updated with two new per SoC callbacks
> (.serdes_get_rcw_override() and .serdes_init_rcwcr()) which get used
> from the generic fsl_guts_lane_set_mode() function. These two callbacks
> hide all the SoC specific register offsets, masks and values so that the
> _set_mode() procedure is straightforward.
> 
> Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
> Cc: Conor Dooley <conor@kernel.org>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: devicetree@vger.kernel.org

Wrong CC list for this specific patch?

ta,
Conor.

> ---
>  drivers/soc/fsl/guts.c   | 286 ++++++++++++++++++++++++++++++++++++++-
>  include/linux/fsl/guts.h |  20 ++-
>  2 files changed, 299 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/soc/fsl/guts.c b/drivers/soc/fsl/guts.c
> index 9f2aff07a274..23ec5750080c 100644
> --- a/drivers/soc/fsl/guts.c
> +++ b/drivers/soc/fsl/guts.c
> @@ -15,6 +15,30 @@
>  #include <linux/fsl/guts.h>
>  
>  #define DCFG_CCSR	0
> +#define DCFG_DCSR	1
> +
> +#define MAX_NUM_LANES	8
> +#define MAX_NUM_SERDES	2
> +
> +#define LS1088A_RCWSR29_SRDS_PRTCL_S1_LNn(lane)	\
> +	GENMASK(19 + 4 * (3 - lane), 16 + 4 * (3 - lane))
> +#define LS1088A_RCWSR30_SRDS_PRTCL_S2_LNn(lane)	\
> +	GENMASK(3 + 4 * (3 - lane), 4 * (3 - lane))
> +
> +#define LS1046A_RCWSR5_SRDS_PRTCL_S1(lane)	\
> +	GENMASK(19 + 4 * (lane), 16 + 4 * (lane))
> +#define SRDS_PRTCL_NONE					0
> +#define SRDS_PRTCL_XFI					1
> +#define SRDS_PRTCL_2500BASEX				2
> +#define SRDS_PRTCL_100BASEX_SGMII			3
> +#define SRDS_PRTCL_QSGMII				4
> +#define SRDS_PRTCL_PCIE					5
> +
> +#define LS2088A_RCWSR30_SRDS_CLK_EN_SEL_XGMII_S1	BIT(14)
> +#define LS2088A_RCWSR30_SRDS_CLK_SEL_XGMII_Ln_S1(lane)	BIT(6 + (7 - (lane)))
> +#define LS2088A_RCWSR30_SRDS_CLK_SEL_MSK		GENMASK(13, 6)
> +#define SRDS_CLK_SEL_XGMII				1
> +#define SRDS_CLK_SEL_GMII				0
>  
>  struct fsl_soc_die_attr {
>  	char	*die;
> @@ -22,9 +46,19 @@ struct fsl_soc_die_attr {
>  	u32	mask;
>  };
>  
> +struct fsl_soc_serdes_rcw_override {
> +	int offset;
> +	int mask;
> +	int val;
> +};
> +
>  struct fsl_soc_data {
>  	const char *sfp_compat;
>  	u32 uid_offset;
> +	int (*serdes_get_rcw_override)(int index, int lane,
> +				       enum lynx_lane_mode lane_mode,
> +				       struct fsl_soc_serdes_rcw_override *override);
> +	void (*serdes_init_rcwcr)(int index);
>  };
>  
>  enum qoriq_die {
> @@ -138,9 +172,13 @@ static const struct fsl_soc_die_attr fsl_soc_die[] = {
>  
>  static struct fsl_soc_guts {
>  	struct ccsr_guts __iomem *dcfg_ccsr;
> +	struct ccsr_guts __iomem *dcfg_dcsr;
>  	const struct fsl_soc_data *data;
>  	bool little_endian;
>  	u32 svr;
> +	enum lynx_lane_mode lane_mode[MAX_NUM_SERDES][MAX_NUM_LANES];
> +	bool rcwcr_init_done;
> +	spinlock_t rcwcr_lock; /* serializes concurrent writes to the RCWCR */
>  } soc;
>  
>  static unsigned int fsl_guts_read(const void __iomem *reg)
> @@ -151,6 +189,28 @@ static unsigned int fsl_guts_read(const void __iomem *reg)
>  	return ioread32be(reg);
>  }
>  
> +static void fsl_guts_write(void __iomem *reg, u32 val)
> +{
> +	if (soc.little_endian)
> +		iowrite32(val, reg);
> +	else
> +		iowrite32be(val, reg);
> +}
> +
> +/* Some fields of the Reset Configuration Word (RCW) can be overridden at
> + * runtime by writing to the RCWCRn registers contained within the DCSR space
> + * of the Device Configuration (DCFG) block. The layout of the RCWCRn registers
> + * is identical with the read-only RCWSRn from the CCSR space.
> + */
> +static void fsl_guts_rmw(int offset, u32 val, u32 mask)
> +{
> +	u32 tmp = fsl_guts_read(&soc.dcfg_ccsr->rcwsr[offset]);
> +
> +	tmp &= ~mask;
> +	tmp |= val;
> +	fsl_guts_write(&soc.dcfg_dcsr->rcwcr[offset], tmp);
> +}
> +
>  static bool fsl_soc_die_match_one(u32 svr, const struct fsl_soc_die_attr *match)
>  {
>  	return match->svr == (svr & match->mask);
> @@ -167,6 +227,97 @@ static const struct fsl_soc_die_attr *fsl_soc_die_match(
>  	return NULL;
>  }
>  
> +static int
> +fsl_guts_serdes_get_rcw_override(int serdes_idx, int lane,
> +				 enum lynx_lane_mode lane_mode,
> +				 struct fsl_soc_serdes_rcw_override *override)
> +{
> +	if ((!fsl_soc_die_match_one(soc.svr, &fsl_soc_die[DIE_LS1088A]) &&
> +	     !fsl_soc_die_match_one(soc.svr, &fsl_soc_die[DIE_LS2088A]) &&
> +	     !fsl_soc_die_match_one(soc.svr, &fsl_soc_die[DIE_LS1046A])) ||
> +	    !soc.data || !soc.data->serdes_get_rcw_override) {
> +		pr_debug("RCW override not implemented for SoC\n");
> +		return -EINVAL;
> +	}
> +
> +	if (!soc.dcfg_dcsr) {
> +		pr_debug("Device tree does not define DCFG_DCSR region necessary for RCW override\n");
> +		return -EINVAL;
> +	}
> +
> +	return soc.data->serdes_get_rcw_override(serdes_idx, lane, lane_mode,
> +						 override);
> +}
> +
> +/**
> + * fsl_guts_lane_init() - Notify guts module of SerDes lane configuration
> + * @serdes_idx: zero-based SerDes block index
> + * @lane: zero-based lane index within SerDes
> + * @lane_mode: initial / boot time SerDes protocol for lane
> + *
> + * On the LS208xA SoC, the RCW override procedure needs to be aware of all link
> + * modes which are configured on a SerDes block.
> + */
> +void fsl_guts_lane_init(int serdes_idx, int lane, enum lynx_lane_mode lane_mode)
> +{
> +	soc.lane_mode[serdes_idx - 1][lane] = lane_mode;
> +}
> +EXPORT_SYMBOL_NS_GPL(fsl_guts_lane_init, "FSL_GUTS");
> +
> +/**
> + * fsl_guts_lane_validate() - Validate that SerDes protocol is implemented and
> + *	supported on current SoC
> + * @serdes_idx: zero-based SerDes block index
> + * @lane: zero-based lane index within SerDes
> + * @lane_mode: requested SerDes protocol
> + *
> + * Should be called before actually requesting the RCW override procedure to be
> + * applied using %fsl_guts_lane_set_mode()
> + *
> + * Return: 0 if RCW override to protocol is possible, negative error otherwise
> + */
> +int fsl_guts_lane_validate(int serdes_idx, int lane, enum lynx_lane_mode lane_mode)
> +{
> +	struct fsl_soc_serdes_rcw_override override;
> +
> +	return fsl_guts_serdes_get_rcw_override(serdes_idx, lane, lane_mode,
> +						&override);
> +}
> +EXPORT_SYMBOL_NS_GPL(fsl_guts_lane_validate, "FSL_GUTS");
> +
> +/**
> + * fsl_guts_lane_set_mode() - apply RCW override procedure for SerDes lane
> + * @serdes_idx: zero-based SerDes block index
> + * @lane: zero-based lane index within SerDes
> + * @lane_mode: requested SerDes protocol
> + *
> + * Return: 0 on success, negative error otherwise
> + */
> +int fsl_guts_lane_set_mode(int serdes_idx, int lane, enum lynx_lane_mode lane_mode)
> +{
> +	struct fsl_soc_serdes_rcw_override override;
> +	int err;
> +
> +	err = fsl_guts_serdes_get_rcw_override(serdes_idx, lane, lane_mode,
> +					       &override);
> +	if (err)
> +		return err;
> +
> +	spin_lock(&soc.rcwcr_lock);
> +
> +	if (soc.data->serdes_init_rcwcr)
> +		soc.data->serdes_init_rcwcr(serdes_idx);
> +
> +	fsl_guts_rmw(override.offset, override.val << __bf_shf(override.mask),
> +		     override.mask);
> +	soc.lane_mode[serdes_idx - 1][lane] = lane_mode;
> +
> +	spin_unlock(&soc.rcwcr_lock);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(fsl_guts_lane_set_mode, "FSL_GUTS");
> +
>  static u64 fsl_guts_get_soc_uid(const char *compat, unsigned int offset)
>  {
>  	struct device_node *np;
> @@ -193,6 +344,128 @@ static u64 fsl_guts_get_soc_uid(const char *compat, unsigned int offset)
>  	return uid;
>  }
>  
> +static int ls1088a_serdes_get_rcw_override(int index, int lane,
> +					   enum lynx_lane_mode lane_mode,
> +					   struct fsl_soc_serdes_rcw_override *override)
> +{
> +	/* The RCW override procedure has to write to different registers
> +	 * depending on the SerDes block index.
> +	 */
> +	switch (index) {
> +	case 1:
> +		override->offset = 28;
> +		override->mask = LS1088A_RCWSR29_SRDS_PRTCL_S1_LNn(lane);
> +		break;
> +	case 2:
> +		override->offset = 29;
> +		override->mask = LS1088A_RCWSR30_SRDS_PRTCL_S2_LNn(lane);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (lynx_lane_mode_uses_xgmii_mac(lane_mode))
> +		override->val = SRDS_PRTCL_XFI;
> +	else if (lynx_lane_mode_uses_gmii_mac(lane_mode))
> +		override->val = SRDS_PRTCL_100BASEX_SGMII;
> +	else
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static int ls1046a_serdes_get_rcw_override(int index, int lane,
> +					   enum lynx_lane_mode lane_mode,
> +					   struct fsl_soc_serdes_rcw_override *override)
> +{
> +	/* The RCW override procedure has to write to different registers
> +	 * depending on the SerDes block index.
> +	 */
> +	switch (index) {
> +	case 1:
> +		override->offset = 4;
> +		override->mask = LS1046A_RCWSR5_SRDS_PRTCL_S1(lane);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (lynx_lane_mode_uses_xgmii_mac(lane_mode))
> +		override->val = SRDS_PRTCL_XFI;
> +	else if (lynx_lane_mode_uses_gmii_mac(lane_mode))
> +		override->val = SRDS_PRTCL_100BASEX_SGMII;
> +	else
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static int ls2088a_serdes_get_rcw_override(int index, int lane,
> +					   enum lynx_lane_mode lane_mode,
> +					   struct fsl_soc_serdes_rcw_override *override)
> +{
> +	switch (index) {
> +	case 1:
> +		override->offset = 29;
> +		override->mask = LS2088A_RCWSR30_SRDS_CLK_SEL_XGMII_Ln_S1(lane);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (lynx_lane_mode_uses_xgmii_mac(lane_mode))
> +		override->val = SRDS_CLK_SEL_XGMII;
> +	else if (lynx_lane_mode_uses_gmii_mac(lane_mode))
> +		override->val = SRDS_CLK_SEL_GMII;
> +	else
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static void ls2088a_serdes_init_rcwcr(int serdes_idx)
> +{
> +	u32 reg;
> +	int i;
> +
> +	if (serdes_idx != 1)
> +		return;
> +	if (soc.rcwcr_init_done)
> +		return;
> +
> +	/* SRDS_CLK_EN_SEL_XGMII_S1: SerDes Clock Enable Select XGMII Serdes 1:
> +	 * Enables to select GMII/XGMII clock according to
> +	 * SRDS_CLK_SEL_XGMII_Ln_S1
> +	 */
> +	reg = LS2088A_RCWSR30_SRDS_CLK_EN_SEL_XGMII_S1;
> +
> +	/* We need to configure the initial state of all lanes for
> +	 * the SerDes block #1
> +	 */
> +	for (i = 0; i < MAX_NUM_LANES; i++)
> +		if (lynx_lane_mode_uses_xgmii_mac(soc.lane_mode[serdes_idx - 1][i]))
> +			reg |= LS2088A_RCWSR30_SRDS_CLK_SEL_XGMII_Ln_S1(i);
> +
> +	fsl_guts_rmw(29, reg,
> +		     LS2088A_RCWSR30_SRDS_CLK_EN_SEL_XGMII_S1 |
> +		     LS2088A_RCWSR30_SRDS_CLK_SEL_MSK);
> +
> +	soc.rcwcr_init_done = true;
> +}
> +
> +static const struct fsl_soc_data ls1088a_data = {
> +	.serdes_get_rcw_override = ls1088a_serdes_get_rcw_override,
> +};
> +
> +static const struct fsl_soc_data ls1046a_data = {
> +	.serdes_get_rcw_override = ls1046a_serdes_get_rcw_override,
> +};
> +
> +static const struct fsl_soc_data ls2088a_data = {
> +	.serdes_get_rcw_override = ls2088a_serdes_get_rcw_override,
> +	.serdes_init_rcwcr = ls2088a_serdes_init_rcwcr,
> +};
> +
>  static const struct fsl_soc_data ls1028a_data = {
>  	.sfp_compat = "fsl,ls1028a-sfp",
>  	.uid_offset = 0x21c,
> @@ -221,10 +494,10 @@ static const struct of_device_id fsl_guts_of_match[] = {
>  	{ .compatible = "fsl,mpc8572-guts", },
>  	{ .compatible = "fsl,ls1021a-dcfg", },
>  	{ .compatible = "fsl,ls1043a-dcfg", },
> -	{ .compatible = "fsl,ls2080a-dcfg", },
> -	{ .compatible = "fsl,ls1088a-dcfg", },
> +	{ .compatible = "fsl,ls2080a-dcfg", .data = &ls2088a_data},
> +	{ .compatible = "fsl,ls1088a-dcfg", .data = &ls1088a_data},
>  	{ .compatible = "fsl,ls1012a-dcfg", },
> -	{ .compatible = "fsl,ls1046a-dcfg", },
> +	{ .compatible = "fsl,ls1046a-dcfg", .data = &ls1046a_data},
>  	{ .compatible = "fsl,lx2160a-dcfg", },
>  	{ .compatible = "fsl,ls1028a-dcfg", .data = &ls1028a_data},
>  	{}
> @@ -250,6 +523,8 @@ static int __init fsl_guts_init(void)
>  		of_node_put(np);
>  		return -ENOMEM;
>  	}
> +	/* DCFG_DCSR is optional */
> +	soc.dcfg_dcsr = of_iomap(np, DCFG_DCSR);
>  
>  	soc.little_endian = of_property_read_bool(np, "little-endian");
>  	soc.svr = fsl_guts_read(&soc.dcfg_ccsr->svr);
> @@ -296,6 +571,8 @@ static int __init fsl_guts_init(void)
>  		goto err;
>  	}
>  
> +	spin_lock_init(&soc.rcwcr_lock);
> +
>  	pr_info("Machine: %s\n", soc_dev_attr->machine);
>  	pr_info("SoC family: %s\n", soc_dev_attr->family);
>  	pr_info("SoC ID: %s, Revision: %s\n",
> @@ -305,7 +582,8 @@ static int __init fsl_guts_init(void)
>  
>  err_nomem:
>  	ret = -ENOMEM;
> -
> +	if (soc.dcfg_dcsr)
> +		iounmap(soc.dcfg_dcsr);
>  	iounmap(soc.dcfg_ccsr);
>  err:
>  	kfree(soc_dev_attr->family);
> diff --git a/include/linux/fsl/guts.h b/include/linux/fsl/guts.h
> index fdb55ca47a4f..176842531241 100644
> --- a/include/linux/fsl/guts.h
> +++ b/include/linux/fsl/guts.h
> @@ -13,6 +13,7 @@
>  
>  #include <linux/types.h>
>  #include <linux/io.h>
> +#include <soc/fsl/phy-fsl-lynx.h>
>  
>  /*
>   * Global Utility Registers.
> @@ -91,9 +92,15 @@ struct ccsr_guts {
>  	u32	iovselsr;	/* 0x.00c0 - I/O voltage select status register
>  					     Called 'elbcvselcr' on 86xx SOCs */
>  	u8	res0c4[0x100 - 0xc4];
> -	u32	rcwsr[16];	/* 0x.0100 - Reset Control Word Status registers
> -					     There are 16 registers */
> -	u8	res140[0x224 - 0x140];
> +	/* 0x.0100 - read-only Reset Configuration Word Status registers in
> +	 * CCSR, or write-only Reset Configuration Word Control registers in
> +	 * DCSR. In both cases there are 32 registers.
> +	 */
> +	union {
> +		u32	rcwsr[32];
> +		u32	rcwcr[32];
> +	};
> +	u8	res180[0x224 - 0x180];
>  	u32	iodelay1;	/* 0x.0224 - IO delay control register 1 */
>  	u32	iodelay2;	/* 0x.0228 - IO delay control register 2 */
>  	u8	res22c[0x604 - 0x22c];
> @@ -131,6 +138,13 @@ struct ccsr_guts {
>  	u32	srds2cr1;	/* 0x.0f44 - SerDes2 Control Register 0 */
>  } __attribute__ ((packed));
>  
> +void fsl_guts_lane_init(int serdes_idx, int lane,
> +			enum lynx_lane_mode lane_mode);
> +int fsl_guts_lane_validate(int serdes_idx, int lane,
> +			   enum lynx_lane_mode lane_mode);
> +int fsl_guts_lane_set_mode(int serdes_idx, int lane,
> +			   enum lynx_lane_mode lane_mode);
> +
>  /* Alternate function signal multiplex control */
>  #define MPC85xx_PMUXCR_QE(x) (0x8000 >> (x))
>  
> -- 
> 2.34.1
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]