[PATCH RESEND net-next v2 0/8] net: stmmac: dwmac-sun8i: Support R40

[PATCH RESEND net-next v2 0/8] net: stmmac: dwmac-sun8i: Support R40

[Chen-Yu Tsai]

This is a resend of the patches for net-next split out from my R40
Ethernet support v2 series, as requested by David Miller. The arm-soc
bits will follow, once I rework the A64 system controller compatible.

Patches 1, 2, and 3 clean up the dwmac-sun8i binding.

Patch 4 adds device tree binding for Allwinner R40's Ethernet
controller.

Patch 5 converts regmap access of the syscon region in the dwmac-sun8i
driver to regmap_field, in anticipation of different field widths on
the R40.

Patch 6 introduces custom plumbing in the dwmac-sun8i driver to fetch
a regmap from another device, by looking up said device via a phandle,
then getting the regmap associated with that device.

Patch 7 adds support for different or absent TX/RX delay chain ranges
to the dwmac-sun8i driver.

Patch 8 adds support for the R40's ethernet controller.


Excerpt from original cover letter:

Changes since v1:

  - Default to fetching regmap from device pointed to by syscon phandle,
    and falling back to syscon API if that fails.

  - Dropped .syscon_from_dev field in device data as a result of the
    previous change.

  - Added a large comment block explaining the first change.

  - Simplified description of syscon property in sun8i-dwmac binding.

  - Regmap now only exposes the EMAC/GMAC register, but retains the
    offset within its address space.

  - Added patches for A64, which reuse the same sun8i-dwmac changes.

This series adds support for the DWMAC based Ethernet controller found
on the Allwinner R40 SoC. The controller is either a DWMAC clone or
DWMAC core with its registers rearranged. This is already supported by
the dwmac-sun8i driver. The glue layer control registers, unlike other
sun8i family SoCs, is not in the system controller region, but in the
clock control unit, like with the older A20 and A31 SoCs.

While we reuse the bindings for dwmac-sun8i using a syscon phandle
reference, we need some custom plumbing for the clock driver to export
a regmap that only allows access to the GMAC register to the dwmac-sun8i
driver. An alternative would be to allow drivers to register custom
syscon devices with their own regmap and locking.


Please have a look.

Regards
ChenYu

Chen-Yu Tsai (8):
  dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions
  dt-bindings: net: dwmac-sun8i: Sort syscon compatibles by alphabetical
    order
  dt-bindings: net: dwmac-sun8i: simplify description of syscon property
  dt-bindings: net: dwmac-sun8i: Add binding for GMAC on Allwinner R40
    SoC
  net: stmmac: dwmac-sun8i: Use regmap_field for syscon register access
  net: stmmac: dwmac-sun8i: Allow getting syscon regmap from external
    device
  net: stmmac: dwmac-sun8i: Support different ranges for TX/RX delay
    chains
  net: stmmac: dwmac-sun8i: Add support for GMAC on Allwinner R40 SoC

 .../devicetree/bindings/net/dwmac-sun8i.txt   |  21 +--
 .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 139 +++++++++++++++---
 2 files changed, 130 insertions(+), 30 deletions(-)

-- 
2.17.0

[PATCH RESEND net-next v2 0/8] net: stmmac: dwmac-sun8i: Support R40

[Chen-Yu Tsai]

This is a resend of the patches for net-next split out from my R40
Ethernet support v2 series, as requested by David Miller. The arm-soc
bits will follow, once I rework the A64 system controller compatible.

Patches 1, 2, and 3 clean up the dwmac-sun8i binding.

Patch 4 adds device tree binding for Allwinner R40's Ethernet
controller.

Patch 5 converts regmap access of the syscon region in the dwmac-sun8i
driver to regmap_field, in anticipation of different field widths on
the R40.

Patch 6 introduces custom plumbing in the dwmac-sun8i driver to fetch
a regmap from another device, by looking up said device via a phandle,
then getting the regmap associated with that device.

Patch 7 adds support for different or absent TX/RX delay chain ranges
to the dwmac-sun8i driver.

Patch 8 adds support for the R40's ethernet controller.


Excerpt from original cover letter:

Changes since v1:

  - Default to fetching regmap from device pointed to by syscon phandle,
    and falling back to syscon API if that fails.

  - Dropped .syscon_from_dev field in device data as a result of the
    previous change.

  - Added a large comment block explaining the first change.

  - Simplified description of syscon property in sun8i-dwmac binding.

  - Regmap now only exposes the EMAC/GMAC register, but retains the
    offset within its address space.

  - Added patches for A64, which reuse the same sun8i-dwmac changes.

This series adds support for the DWMAC based Ethernet controller found
on the Allwinner R40 SoC. The controller is either a DWMAC clone or
DWMAC core with its registers rearranged. This is already supported by
the dwmac-sun8i driver. The glue layer control registers, unlike other
sun8i family SoCs, is not in the system controller region, but in the
clock control unit, like with the older A20 and A31 SoCs.

While we reuse the bindings for dwmac-sun8i using a syscon phandle
reference, we need some custom plumbing for the clock driver to export
a regmap that only allows access to the GMAC register to the dwmac-sun8i
driver. An alternative would be to allow drivers to register custom
syscon devices with their own regmap and locking.


Please have a look.

Regards
ChenYu

Chen-Yu Tsai (8):
  dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions
  dt-bindings: net: dwmac-sun8i: Sort syscon compatibles by alphabetical
    order
  dt-bindings: net: dwmac-sun8i: simplify description of syscon property
  dt-bindings: net: dwmac-sun8i: Add binding for GMAC on Allwinner R40
    SoC
  net: stmmac: dwmac-sun8i: Use regmap_field for syscon register access
  net: stmmac: dwmac-sun8i: Allow getting syscon regmap from external
    device
  net: stmmac: dwmac-sun8i: Support different ranges for TX/RX delay
    chains
  net: stmmac: dwmac-sun8i: Add support for GMAC on Allwinner R40 SoC

 .../devicetree/bindings/net/dwmac-sun8i.txt   |  21 +--
 .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 139 +++++++++++++++---
 2 files changed, 130 insertions(+), 30 deletions(-)

-- 
2.17.0

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Chen-Yu Tsai]

The clock delay chains found in the glue layer for dwmac-sun8i are only
used with RGMII PHYs. They are not intended for non-RGMII PHYs, such as
MII external PHYs or the internal PHY. Also, a recent SoC has a smaller
range of possible values for the delay chain.

This patch reformats the delay chain section of the device tree binding
to make it clear that the delay chains only apply to RGMII PHYs, and
make it easier to add the R40-specific bits later.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
index 3d6d5fa0c4d5..e04ce75e24a3 100644
--- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
+++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
@@ -28,10 +28,13 @@ Required properties:
   - allwinner,sun8i-a83t-system-controller
 
 Optional properties:
-- allwinner,tx-delay-ps: TX clock delay chain value in ps. Range value is 0-700. Default is 0)
-- allwinner,rx-delay-ps: RX clock delay chain value in ps. Range value is 0-3100. Default is 0)
-Both delay properties need to be a multiple of 100. They control the delay for
-external PHY.
+- allwinner,tx-delay-ps: TX clock delay chain value in ps.
+			 Range is 0-700. Default is 0.
+- allwinner,rx-delay-ps: RX clock delay chain value in ps.
+			 Range is 0-3100. Default is 0.
+Both delay properties need to be a multiple of 100. They control the
+clock delay for external RGMII PHY. They do not apply to the internal
+PHY or external non-RGMII PHYs.
 
 Optional properties for the following compatibles:
   - "allwinner,sun8i-h3-emac",
-- 
2.17.0

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Chen-Yu Tsai]

The clock delay chains found in the glue layer for dwmac-sun8i are only
used with RGMII PHYs. They are not intended for non-RGMII PHYs, such as
MII external PHYs or the internal PHY. Also, a recent SoC has a smaller
range of possible values for the delay chain.

This patch reformats the delay chain section of the device tree binding
to make it clear that the delay chains only apply to RGMII PHYs, and
make it easier to add the R40-specific bits later.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
index 3d6d5fa0c4d5..e04ce75e24a3 100644
--- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
+++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
@@ -28,10 +28,13 @@ Required properties:
   - allwinner,sun8i-a83t-system-controller
 
 Optional properties:
-- allwinner,tx-delay-ps: TX clock delay chain value in ps. Range value is 0-700. Default is 0)
-- allwinner,rx-delay-ps: RX clock delay chain value in ps. Range value is 0-3100. Default is 0)
-Both delay properties need to be a multiple of 100. They control the delay for
-external PHY.
+- allwinner,tx-delay-ps: TX clock delay chain value in ps.
+			 Range is 0-700. Default is 0.
+- allwinner,rx-delay-ps: RX clock delay chain value in ps.
+			 Range is 0-3100. Default is 0.
+Both delay properties need to be a multiple of 100. They control the
+clock delay for external RGMII PHY. They do not apply to the internal
+PHY or external non-RGMII PHYs.
 
 Optional properties for the following compatibles:
   - "allwinner,sun8i-h3-emac",
-- 
2.17.0

[PATCH RESEND net-next v2 2/8] dt-bindings: net: dwmac-sun8i: Sort syscon compatibles by alphabetical order

[Chen-Yu Tsai]

The A83T syscon compatible was appended to the syscon compatibles list,
instead of inserted in to preserve the ordering.

Move it to the proper place to keep the list sorted.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
index e04ce75e24a3..1b8e33e71651 100644
--- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
+++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
@@ -22,10 +22,10 @@ Required properties:
 - #size-cells: shall be 0
 - syscon: A phandle to the syscon of the SoC with one of the following
  compatible string:
+  - allwinner,sun8i-a83t-system-controller
   - allwinner,sun8i-h3-system-controller
   - allwinner,sun8i-v3s-system-controller
   - allwinner,sun50i-a64-system-controller
-  - allwinner,sun8i-a83t-system-controller
 
 Optional properties:
 - allwinner,tx-delay-ps: TX clock delay chain value in ps.
-- 
2.17.0

[PATCH RESEND net-next v2 2/8] dt-bindings: net: dwmac-sun8i: Sort syscon compatibles by alphabetical order

[Chen-Yu Tsai]

The A83T syscon compatible was appended to the syscon compatibles list,
instead of inserted in to preserve the ordering.

Move it to the proper place to keep the list sorted.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
index e04ce75e24a3..1b8e33e71651 100644
--- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
+++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
@@ -22,10 +22,10 @@ Required properties:
 - #size-cells: shall be 0
 - syscon: A phandle to the syscon of the SoC with one of the following
  compatible string:
+  - allwinner,sun8i-a83t-system-controller
   - allwinner,sun8i-h3-system-controller
   - allwinner,sun8i-v3s-system-controller
   - allwinner,sun50i-a64-system-controller
-  - allwinner,sun8i-a83t-system-controller
 
 Optional properties:
 - allwinner,tx-delay-ps: TX clock delay chain value in ps.
-- 
2.17.0

[PATCH RESEND net-next v2 3/8] dt-bindings: net: dwmac-sun8i: simplify description of syscon property

[Chen-Yu Tsai]

The syscon property is used to point to the device that holds the glue
layer control register known as the "EMAC (or GMAC) clock register".

We do not need to explicitly list what compatible strings are needed, as
this information is readily available in the user manuals. Also the
"syscon" device type is more of an implementation detail. There are many
ways to access a register not in a device's address range, the syscon
interface being the most generic and unrestricted one.

Simplify the description so that it says what it is supposed to
describe.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
index 1b8e33e71651..1c0906a5c02b 100644
--- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
+++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
@@ -20,12 +20,7 @@ Required properties:
 - phy-handle: See ethernet.txt
 - #address-cells: shall be 1
 - #size-cells: shall be 0
-- syscon: A phandle to the syscon of the SoC with one of the following
- compatible string:
-  - allwinner,sun8i-a83t-system-controller
-  - allwinner,sun8i-h3-system-controller
-  - allwinner,sun8i-v3s-system-controller
-  - allwinner,sun50i-a64-system-controller
+- syscon: A phandle to the device containing the EMAC or GMAC clock register
 
 Optional properties:
 - allwinner,tx-delay-ps: TX clock delay chain value in ps.
-- 
2.17.0

[PATCH RESEND net-next v2 3/8] dt-bindings: net: dwmac-sun8i: simplify description of syscon property

[Chen-Yu Tsai]

The syscon property is used to point to the device that holds the glue
layer control register known as the "EMAC (or GMAC) clock register".

We do not need to explicitly list what compatible strings are needed, as
this information is readily available in the user manuals. Also the
"syscon" device type is more of an implementation detail. There are many
ways to access a register not in a device's address range, the syscon
interface being the most generic and unrestricted one.

Simplify the description so that it says what it is supposed to
describe.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
index 1b8e33e71651..1c0906a5c02b 100644
--- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
+++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
@@ -20,12 +20,7 @@ Required properties:
 - phy-handle: See ethernet.txt
 - #address-cells: shall be 1
 - #size-cells: shall be 0
-- syscon: A phandle to the syscon of the SoC with one of the following
- compatible string:
-  - allwinner,sun8i-a83t-system-controller
-  - allwinner,sun8i-h3-system-controller
-  - allwinner,sun8i-v3s-system-controller
-  - allwinner,sun50i-a64-system-controller
+- syscon: A phandle to the device containing the EMAC or GMAC clock register
 
 Optional properties:
 - allwinner,tx-delay-ps: TX clock delay chain value in ps.
-- 
2.17.0

[PATCH RESEND net-next v2 4/8] dt-bindings: net: dwmac-sun8i: Add binding for GMAC on Allwinner R40 SoC

[Chen-Yu Tsai]

The Allwinner R40 SoC has the EMAC controller supported by dwmac-sun8i.
It is named "GMAC", while EMAC refers to the 10/100 Mbps Ethernet
controller supported by sun4i-emac. The controller is the same, but
the R40 has the glue layer controls in the clock control unit (CCU),
with a reduced RX delay chain, and no TX delay chain.

This patch adds the R40 specific bits to the dwmac-sun8i binding.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
index 1c0906a5c02b..cfe724398a12 100644
--- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
+++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
@@ -7,6 +7,7 @@ Required properties:
 - compatible: must be one of the following string:
 		"allwinner,sun8i-a83t-emac"
 		"allwinner,sun8i-h3-emac"
+		"allwinner,sun8i-r40-gmac"
 		"allwinner,sun8i-v3s-emac"
 		"allwinner,sun50i-a64-emac"
 - reg: address and length of the register for the device.
@@ -25,8 +26,10 @@ Required properties:
 Optional properties:
 - allwinner,tx-delay-ps: TX clock delay chain value in ps.
 			 Range is 0-700. Default is 0.
+			 Unavailable for allwinner,sun8i-r40-gmac
 - allwinner,rx-delay-ps: RX clock delay chain value in ps.
 			 Range is 0-3100. Default is 0.
+			 Range is 0-700 for allwinner,sun8i-r40-gmac
 Both delay properties need to be a multiple of 100. They control the
 clock delay for external RGMII PHY. They do not apply to the internal
 PHY or external non-RGMII PHYs.
-- 
2.17.0

[PATCH RESEND net-next v2 4/8] dt-bindings: net: dwmac-sun8i: Add binding for GMAC on Allwinner R40 SoC

[Chen-Yu Tsai]

The Allwinner R40 SoC has the EMAC controller supported by dwmac-sun8i.
It is named "GMAC", while EMAC refers to the 10/100 Mbps Ethernet
controller supported by sun4i-emac. The controller is the same, but
the R40 has the glue layer controls in the clock control unit (CCU),
with a reduced RX delay chain, and no TX delay chain.

This patch adds the R40 specific bits to the dwmac-sun8i binding.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
index 1c0906a5c02b..cfe724398a12 100644
--- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
+++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
@@ -7,6 +7,7 @@ Required properties:
 - compatible: must be one of the following string:
 		"allwinner,sun8i-a83t-emac"
 		"allwinner,sun8i-h3-emac"
+		"allwinner,sun8i-r40-gmac"
 		"allwinner,sun8i-v3s-emac"
 		"allwinner,sun50i-a64-emac"
 - reg: address and length of the register for the device.
@@ -25,8 +26,10 @@ Required properties:
 Optional properties:
 - allwinner,tx-delay-ps: TX clock delay chain value in ps.
 			 Range is 0-700. Default is 0.
+			 Unavailable for allwinner,sun8i-r40-gmac
 - allwinner,rx-delay-ps: RX clock delay chain value in ps.
 			 Range is 0-3100. Default is 0.
+			 Range is 0-700 for allwinner,sun8i-r40-gmac
 Both delay properties need to be a multiple of 100. They control the
 clock delay for external RGMII PHY. They do not apply to the internal
 PHY or external non-RGMII PHYs.
-- 
2.17.0

[PATCH RESEND net-next v2 5/8] net: stmmac: dwmac-sun8i: Use regmap_field for syscon register access

[Chen-Yu Tsai]

On the Allwinner R40, the "GMAC clock" register is located in the CCU
block, at a different register address than the other SoCs that have
it in the "system control" block.

This patch converts the use of regmap to regmap_field for mapping and
accessing the syscon register, so we can have the register address in
the variants data, and not in the actual register manipulation code.

This patch only converts regmap_read() and regmap_write() calls to
regmap_field_read() and regmap_field_write() calls. There are some
places where it might make sense to switch to regmap_field_update_bits(),
but this is not done here to keep the patch simple.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 42 ++++++++++++++-----
 1 file changed, 31 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
index a3fa65b1ca8e..bbc051474806 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
@@ -42,6 +42,7 @@
  *				This value is used for disabling properly EMAC
  *				and used as a good starting value in case of the
  *				boot process(uboot) leave some stuff.
+ * @syscon_field		reg_field for the syscon's gmac register
  * @soc_has_internal_phy:	Does the MAC embed an internal PHY
  * @support_mii:		Does the MAC handle MII
  * @support_rmii:		Does the MAC handle RMII
@@ -49,6 +50,7 @@
  */
 struct emac_variant {
 	u32 default_syscon_value;
+	const struct reg_field *syscon_field;
 	bool soc_has_internal_phy;
 	bool support_mii;
 	bool support_rmii;
@@ -71,13 +73,21 @@ struct sunxi_priv_data {
 	struct regulator *regulator;
 	struct reset_control *rst_ephy;
 	const struct emac_variant *variant;
-	struct regmap *regmap;
+	struct regmap_field *regmap_field;
 	bool internal_phy_powered;
 	void *mux_handle;
 };
 
+/* EMAC clock register @ 0x30 in the "system control" address range */
+static const struct reg_field sun8i_syscon_reg_field = {
+	.reg = 0x30,
+	.lsb = 0,
+	.msb = 31,
+};
+
 static const struct emac_variant emac_variant_h3 = {
 	.default_syscon_value = 0x58000,
+	.syscon_field = &sun8i_syscon_reg_field,
 	.soc_has_internal_phy = true,
 	.support_mii = true,
 	.support_rmii = true,
@@ -86,12 +96,14 @@ static const struct emac_variant emac_variant_h3 = {
 
 static const struct emac_variant emac_variant_v3s = {
 	.default_syscon_value = 0x38000,
+	.syscon_field = &sun8i_syscon_reg_field,
 	.soc_has_internal_phy = true,
 	.support_mii = true
 };
 
 static const struct emac_variant emac_variant_a83t = {
 	.default_syscon_value = 0,
+	.syscon_field = &sun8i_syscon_reg_field,
 	.soc_has_internal_phy = false,
 	.support_mii = true,
 	.support_rgmii = true
@@ -99,6 +111,7 @@ static const struct emac_variant emac_variant_a83t = {
 
 static const struct emac_variant emac_variant_a64 = {
 	.default_syscon_value = 0,
+	.syscon_field = &sun8i_syscon_reg_field,
 	.soc_has_internal_phy = false,
 	.support_mii = true,
 	.support_rmii = true,
@@ -216,7 +229,6 @@ static const struct emac_variant emac_variant_a64 = {
 #define SYSCON_ETCS_MII		0x0
 #define SYSCON_ETCS_EXT_GMII	0x1
 #define SYSCON_ETCS_INT_GMII	0x2
-#define SYSCON_EMAC_REG		0x30
 
 /* sun8i_dwmac_dma_reset() - reset the EMAC
  * Called from stmmac via stmmac_dma_ops->reset
@@ -745,7 +757,7 @@ static int mdio_mux_syscon_switch_fn(int current_child, int desired_child,
 	bool need_power_ephy = false;
 
 	if (current_child ^ desired_child) {
-		regmap_read(gmac->regmap, SYSCON_EMAC_REG, &reg);
+		regmap_field_read(gmac->regmap_field, &reg);
 		switch (desired_child) {
 		case DWMAC_SUN8I_MDIO_MUX_INTERNAL_ID:
 			dev_info(priv->device, "Switch mux to internal PHY");
@@ -763,7 +775,7 @@ static int mdio_mux_syscon_switch_fn(int current_child, int desired_child,
 				desired_child);
 			return -EINVAL;
 		}
-		regmap_write(gmac->regmap, SYSCON_EMAC_REG, val);
+		regmap_field_write(gmac->regmap_field, val);
 		if (need_power_ephy) {
 			ret = sun8i_dwmac_power_internal_phy(priv);
 			if (ret)
@@ -801,7 +813,7 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 	int ret;
 	u32 reg, val;
 
-	regmap_read(gmac->regmap, SYSCON_EMAC_REG, &val);
+	regmap_field_read(gmac->regmap_field, &val);
 	reg = gmac->variant->default_syscon_value;
 	if (reg != val)
 		dev_warn(priv->device,
@@ -883,7 +895,7 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 		return -EINVAL;
 	}
 
-	regmap_write(gmac->regmap, SYSCON_EMAC_REG, reg);
+	regmap_field_write(gmac->regmap_field, reg);
 
 	return 0;
 }
@@ -892,7 +904,7 @@ static void sun8i_dwmac_unset_syscon(struct sunxi_priv_data *gmac)
 {
 	u32 reg = gmac->variant->default_syscon_value;
 
-	regmap_write(gmac->regmap, SYSCON_EMAC_REG, reg);
+	regmap_field_write(gmac->regmap_field, reg);
 }
 
 static void sun8i_dwmac_exit(struct platform_device *pdev, void *priv)
@@ -980,6 +992,7 @@ static int sun8i_dwmac_probe(struct platform_device *pdev)
 	int ret;
 	struct stmmac_priv *priv;
 	struct net_device *ndev;
+	struct regmap *regmap;
 
 	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
 	if (ret)
@@ -1014,14 +1027,21 @@ static int sun8i_dwmac_probe(struct platform_device *pdev)
 		gmac->regulator = NULL;
 	}
 
-	gmac->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
-						       "syscon");
-	if (IS_ERR(gmac->regmap)) {
-		ret = PTR_ERR(gmac->regmap);
+	regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "syscon");
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
 		dev_err(&pdev->dev, "Unable to map syscon: %d\n", ret);
 		return ret;
 	}
 
+	gmac->regmap_field = devm_regmap_field_alloc(dev, regmap,
+						     *gmac->variant->syscon_field);
+	if (IS_ERR(gmac->regmap_field)) {
+		ret = PTR_ERR(gmac->regmap_field);
+		dev_err(dev, "Unable to map syscon register: %d\n", ret);
+		return ret;
+	}
+
 	plat_dat->interface = of_get_phy_mode(dev->of_node);
 
 	/* platform data specifying hardware features and callbacks.
-- 
2.17.0

[PATCH RESEND net-next v2 5/8] net: stmmac: dwmac-sun8i: Use regmap_field for syscon register access

[Chen-Yu Tsai]

On the Allwinner R40, the "GMAC clock" register is located in the CCU
block, at a different register address than the other SoCs that have
it in the "system control" block.

This patch converts the use of regmap to regmap_field for mapping and
accessing the syscon register, so we can have the register address in
the variants data, and not in the actual register manipulation code.

This patch only converts regmap_read() and regmap_write() calls to
regmap_field_read() and regmap_field_write() calls. There are some
places where it might make sense to switch to regmap_field_update_bits(),
but this is not done here to keep the patch simple.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 42 ++++++++++++++-----
 1 file changed, 31 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
index a3fa65b1ca8e..bbc051474806 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
@@ -42,6 +42,7 @@
  *				This value is used for disabling properly EMAC
  *				and used as a good starting value in case of the
  *				boot process(uboot) leave some stuff.
+ * @syscon_field		reg_field for the syscon's gmac register
  * @soc_has_internal_phy:	Does the MAC embed an internal PHY
  * @support_mii:		Does the MAC handle MII
  * @support_rmii:		Does the MAC handle RMII
@@ -49,6 +50,7 @@
  */
 struct emac_variant {
 	u32 default_syscon_value;
+	const struct reg_field *syscon_field;
 	bool soc_has_internal_phy;
 	bool support_mii;
 	bool support_rmii;
@@ -71,13 +73,21 @@ struct sunxi_priv_data {
 	struct regulator *regulator;
 	struct reset_control *rst_ephy;
 	const struct emac_variant *variant;
-	struct regmap *regmap;
+	struct regmap_field *regmap_field;
 	bool internal_phy_powered;
 	void *mux_handle;
 };
 
+/* EMAC clock register @ 0x30 in the "system control" address range */
+static const struct reg_field sun8i_syscon_reg_field = {
+	.reg = 0x30,
+	.lsb = 0,
+	.msb = 31,
+};
+
 static const struct emac_variant emac_variant_h3 = {
 	.default_syscon_value = 0x58000,
+	.syscon_field = &sun8i_syscon_reg_field,
 	.soc_has_internal_phy = true,
 	.support_mii = true,
 	.support_rmii = true,
@@ -86,12 +96,14 @@ static const struct emac_variant emac_variant_h3 = {
 
 static const struct emac_variant emac_variant_v3s = {
 	.default_syscon_value = 0x38000,
+	.syscon_field = &sun8i_syscon_reg_field,
 	.soc_has_internal_phy = true,
 	.support_mii = true
 };
 
 static const struct emac_variant emac_variant_a83t = {
 	.default_syscon_value = 0,
+	.syscon_field = &sun8i_syscon_reg_field,
 	.soc_has_internal_phy = false,
 	.support_mii = true,
 	.support_rgmii = true
@@ -99,6 +111,7 @@ static const struct emac_variant emac_variant_a83t = {
 
 static const struct emac_variant emac_variant_a64 = {
 	.default_syscon_value = 0,
+	.syscon_field = &sun8i_syscon_reg_field,
 	.soc_has_internal_phy = false,
 	.support_mii = true,
 	.support_rmii = true,
@@ -216,7 +229,6 @@ static const struct emac_variant emac_variant_a64 = {
 #define SYSCON_ETCS_MII		0x0
 #define SYSCON_ETCS_EXT_GMII	0x1
 #define SYSCON_ETCS_INT_GMII	0x2
-#define SYSCON_EMAC_REG		0x30
 
 /* sun8i_dwmac_dma_reset() - reset the EMAC
  * Called from stmmac via stmmac_dma_ops->reset
@@ -745,7 +757,7 @@ static int mdio_mux_syscon_switch_fn(int current_child, int desired_child,
 	bool need_power_ephy = false;
 
 	if (current_child ^ desired_child) {
-		regmap_read(gmac->regmap, SYSCON_EMAC_REG, &reg);
+		regmap_field_read(gmac->regmap_field, &reg);
 		switch (desired_child) {
 		case DWMAC_SUN8I_MDIO_MUX_INTERNAL_ID:
 			dev_info(priv->device, "Switch mux to internal PHY");
@@ -763,7 +775,7 @@ static int mdio_mux_syscon_switch_fn(int current_child, int desired_child,
 				desired_child);
 			return -EINVAL;
 		}
-		regmap_write(gmac->regmap, SYSCON_EMAC_REG, val);
+		regmap_field_write(gmac->regmap_field, val);
 		if (need_power_ephy) {
 			ret = sun8i_dwmac_power_internal_phy(priv);
 			if (ret)
@@ -801,7 +813,7 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 	int ret;
 	u32 reg, val;
 
-	regmap_read(gmac->regmap, SYSCON_EMAC_REG, &val);
+	regmap_field_read(gmac->regmap_field, &val);
 	reg = gmac->variant->default_syscon_value;
 	if (reg != val)
 		dev_warn(priv->device,
@@ -883,7 +895,7 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 		return -EINVAL;
 	}
 
-	regmap_write(gmac->regmap, SYSCON_EMAC_REG, reg);
+	regmap_field_write(gmac->regmap_field, reg);
 
 	return 0;
 }
@@ -892,7 +904,7 @@ static void sun8i_dwmac_unset_syscon(struct sunxi_priv_data *gmac)
 {
 	u32 reg = gmac->variant->default_syscon_value;
 
-	regmap_write(gmac->regmap, SYSCON_EMAC_REG, reg);
+	regmap_field_write(gmac->regmap_field, reg);
 }
 
 static void sun8i_dwmac_exit(struct platform_device *pdev, void *priv)
@@ -980,6 +992,7 @@ static int sun8i_dwmac_probe(struct platform_device *pdev)
 	int ret;
 	struct stmmac_priv *priv;
 	struct net_device *ndev;
+	struct regmap *regmap;
 
 	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
 	if (ret)
@@ -1014,14 +1027,21 @@ static int sun8i_dwmac_probe(struct platform_device *pdev)
 		gmac->regulator = NULL;
 	}
 
-	gmac->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
-						       "syscon");
-	if (IS_ERR(gmac->regmap)) {
-		ret = PTR_ERR(gmac->regmap);
+	regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "syscon");
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
 		dev_err(&pdev->dev, "Unable to map syscon: %d\n", ret);
 		return ret;
 	}
 
+	gmac->regmap_field = devm_regmap_field_alloc(dev, regmap,
+						     *gmac->variant->syscon_field);
+	if (IS_ERR(gmac->regmap_field)) {
+		ret = PTR_ERR(gmac->regmap_field);
+		dev_err(dev, "Unable to map syscon register: %d\n", ret);
+		return ret;
+	}
+
 	plat_dat->interface = of_get_phy_mode(dev->of_node);
 
 	/* platform data specifying hardware features and callbacks.
-- 
2.17.0

[PATCH RESEND net-next v2 6/8] net: stmmac: dwmac-sun8i: Allow getting syscon regmap from external device

[Chen-Yu Tsai]

On the Allwinner R40 SoC, the "GMAC clock" register is in the CCU
address space. Using a standard syscon to access it provides no
coordination with the CCU driver for register access. Neither does
it prevent this and other drivers from accessing other, maybe critical,
clock control registers. On other SoCs, the register is in the "system
control" address space, which might also contain controls for mapping
SRAM to devices or the CPU. This hardware has the same issues.

Instead, for these types of setups, we let the device containing the
control register create a regmap tied to it. We can then get the device
from the existing syscon phandle, and retrieve the regmap with
dev_get_regmap().

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 50 ++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
index bbc051474806..79e104a20e20 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
@@ -983,6 +983,34 @@ static struct mac_device_info *sun8i_dwmac_setup(void *ppriv)
 	return mac;
 }
 
+static struct regmap *sun8i_dwmac_get_syscon_from_dev(struct device_node *node)
+{
+	struct device_node *syscon_node;
+	struct platform_device *syscon_pdev;
+	struct regmap *regmap = NULL;
+
+	syscon_node = of_parse_phandle(node, "syscon", 0);
+	if (!syscon_node)
+		return ERR_PTR(-ENODEV);
+
+	syscon_pdev = of_find_device_by_node(syscon_node);
+	if (!syscon_pdev) {
+		/* platform device might not be probed yet */
+		regmap = ERR_PTR(-EPROBE_DEFER);
+		goto out_put_node;
+	}
+
+	/* If no regmap is found then the other device driver is at fault */
+	regmap = dev_get_regmap(&syscon_pdev->dev, NULL);
+	if (!regmap)
+		regmap = ERR_PTR(-EINVAL);
+
+	platform_device_put(syscon_pdev);
+out_put_node:
+	of_node_put(syscon_node);
+	return regmap;
+}
+
 static int sun8i_dwmac_probe(struct platform_device *pdev)
 {
 	struct plat_stmmacenet_data *plat_dat;
@@ -1027,7 +1055,27 @@ static int sun8i_dwmac_probe(struct platform_device *pdev)
 		gmac->regulator = NULL;
 	}
 
-	regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "syscon");
+	/* The "GMAC clock control" register might be located in the
+	 * CCU address range (on the R40), or the system control address
+	 * range (on most other sun8i and later SoCs).
+	 *
+	 * The former controls most if not all clocks in the SoC. The
+	 * latter has an SoC identification register, and on some SoCs,
+	 * controls to map device specific SRAM to either the intended
+	 * peripheral, or the CPU address space.
+	 *
+	 * In either case, there should be a coordinated and restricted
+	 * method of accessing the register needed here. This is done by
+	 * having the device export a custom regmap, instead of a generic
+	 * syscon, which grants all access to all registers.
+	 *
+	 * To support old device trees, we fall back to using the syscon
+	 * interface if possible.
+	 */
+	regmap = sun8i_dwmac_get_syscon_from_dev(pdev->dev.of_node);
+	if (IS_ERR(regmap))
+		regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+							 "syscon");
 	if (IS_ERR(regmap)) {
 		ret = PTR_ERR(regmap);
 		dev_err(&pdev->dev, "Unable to map syscon: %d\n", ret);
-- 
2.17.0

[PATCH RESEND net-next v2 6/8] net: stmmac: dwmac-sun8i: Allow getting syscon regmap from external device

[Chen-Yu Tsai]

On the Allwinner R40 SoC, the "GMAC clock" register is in the CCU
address space. Using a standard syscon to access it provides no
coordination with the CCU driver for register access. Neither does
it prevent this and other drivers from accessing other, maybe critical,
clock control registers. On other SoCs, the register is in the "system
control" address space, which might also contain controls for mapping
SRAM to devices or the CPU. This hardware has the same issues.

Instead, for these types of setups, we let the device containing the
control register create a regmap tied to it. We can then get the device
from the existing syscon phandle, and retrieve the regmap with
dev_get_regmap().

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 50 ++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
index bbc051474806..79e104a20e20 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
@@ -983,6 +983,34 @@ static struct mac_device_info *sun8i_dwmac_setup(void *ppriv)
 	return mac;
 }
 
+static struct regmap *sun8i_dwmac_get_syscon_from_dev(struct device_node *node)
+{
+	struct device_node *syscon_node;
+	struct platform_device *syscon_pdev;
+	struct regmap *regmap = NULL;
+
+	syscon_node = of_parse_phandle(node, "syscon", 0);
+	if (!syscon_node)
+		return ERR_PTR(-ENODEV);
+
+	syscon_pdev = of_find_device_by_node(syscon_node);
+	if (!syscon_pdev) {
+		/* platform device might not be probed yet */
+		regmap = ERR_PTR(-EPROBE_DEFER);
+		goto out_put_node;
+	}
+
+	/* If no regmap is found then the other device driver is at fault */
+	regmap = dev_get_regmap(&syscon_pdev->dev, NULL);
+	if (!regmap)
+		regmap = ERR_PTR(-EINVAL);
+
+	platform_device_put(syscon_pdev);
+out_put_node:
+	of_node_put(syscon_node);
+	return regmap;
+}
+
 static int sun8i_dwmac_probe(struct platform_device *pdev)
 {
 	struct plat_stmmacenet_data *plat_dat;
@@ -1027,7 +1055,27 @@ static int sun8i_dwmac_probe(struct platform_device *pdev)
 		gmac->regulator = NULL;
 	}
 
-	regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "syscon");
+	/* The "GMAC clock control" register might be located in the
+	 * CCU address range (on the R40), or the system control address
+	 * range (on most other sun8i and later SoCs).
+	 *
+	 * The former controls most if not all clocks in the SoC. The
+	 * latter has an SoC identification register, and on some SoCs,
+	 * controls to map device specific SRAM to either the intended
+	 * peripheral, or the CPU address space.
+	 *
+	 * In either case, there should be a coordinated and restricted
+	 * method of accessing the register needed here. This is done by
+	 * having the device export a custom regmap, instead of a generic
+	 * syscon, which grants all access to all registers.
+	 *
+	 * To support old device trees, we fall back to using the syscon
+	 * interface if possible.
+	 */
+	regmap = sun8i_dwmac_get_syscon_from_dev(pdev->dev.of_node);
+	if (IS_ERR(regmap))
+		regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+							 "syscon");
 	if (IS_ERR(regmap)) {
 		ret = PTR_ERR(regmap);
 		dev_err(&pdev->dev, "Unable to map syscon: %d\n", ret);
-- 
2.17.0

[PATCH RESEND net-next v2 7/8] net: stmmac: dwmac-sun8i: Support different ranges for TX/RX delay chains

[Chen-Yu Tsai]

On the R40 SoC, the RX delay chain only has a range of 0~7 (hundred
picoseconds), instead of 0~31. Also the TX delay chain is completely
absent.

This patch adds support for different ranges by adding per-compatible
maximum values in the variant data. A maximum of 0 indicates that the
delay chain is not supported or absent.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 32 +++++++++++++------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
index 79e104a20e20..4f5612a3c855 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
@@ -47,6 +47,12 @@
  * @support_mii:		Does the MAC handle MII
  * @support_rmii:		Does the MAC handle RMII
  * @support_rgmii:		Does the MAC handle RGMII
+ *
+ * @rx_delay_max:		Maximum raw value for RX delay chain
+ * @tx_delay_max:		Maximum raw value for TX delay chain
+ *				These two also indicate the bitmask for
+ *				the RX and TX delay chain registers. A
+ *				value of zero indicates this is not supported.
  */
 struct emac_variant {
 	u32 default_syscon_value;
@@ -55,6 +61,8 @@ struct emac_variant {
 	bool support_mii;
 	bool support_rmii;
 	bool support_rgmii;
+	u8 rx_delay_max;
+	u8 tx_delay_max;
 };
 
 /* struct sunxi_priv_data - hold all sunxi private data
@@ -91,7 +99,9 @@ static const struct emac_variant emac_variant_h3 = {
 	.soc_has_internal_phy = true,
 	.support_mii = true,
 	.support_rmii = true,
-	.support_rgmii = true
+	.support_rgmii = true,
+	.rx_delay_max = 31,
+	.tx_delay_max = 7,
 };
 
 static const struct emac_variant emac_variant_v3s = {
@@ -106,7 +116,9 @@ static const struct emac_variant emac_variant_a83t = {
 	.syscon_field = &sun8i_syscon_reg_field,
 	.soc_has_internal_phy = false,
 	.support_mii = true,
-	.support_rgmii = true
+	.support_rgmii = true,
+	.rx_delay_max = 31,
+	.tx_delay_max = 7,
 };
 
 static const struct emac_variant emac_variant_a64 = {
@@ -115,7 +127,9 @@ static const struct emac_variant emac_variant_a64 = {
 	.soc_has_internal_phy = false,
 	.support_mii = true,
 	.support_rmii = true,
-	.support_rgmii = true
+	.support_rgmii = true,
+	.rx_delay_max = 31,
+	.tx_delay_max = 7,
 };
 
 #define EMAC_BASIC_CTL0 0x00
@@ -219,9 +233,7 @@ static const struct emac_variant emac_variant_a64 = {
 #define SYSCON_RMII_EN		BIT(13) /* 1: enable RMII (overrides EPIT) */
 
 /* Generic system control EMAC_CLK bits */
-#define SYSCON_ETXDC_MASK		GENMASK(2, 0)
 #define SYSCON_ETXDC_SHIFT		10
-#define SYSCON_ERXDC_MASK		GENMASK(4, 0)
 #define SYSCON_ERXDC_SHIFT		5
 /* EMAC PHY Interface Type */
 #define SYSCON_EPIT			BIT(2) /* 1: RGMII, 0: MII */
@@ -847,8 +859,9 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 		}
 		val /= 100;
 		dev_dbg(priv->device, "set tx-delay to %x\n", val);
-		if (val <= SYSCON_ETXDC_MASK) {
-			reg &= ~(SYSCON_ETXDC_MASK << SYSCON_ETXDC_SHIFT);
+		if (val <= gmac->variant->tx_delay_max) {
+			reg &= ~(gmac->variant->tx_delay_max <<
+				 SYSCON_ETXDC_SHIFT);
 			reg |= (val << SYSCON_ETXDC_SHIFT);
 		} else {
 			dev_err(priv->device, "Invalid TX clock delay: %d\n",
@@ -864,8 +877,9 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 		}
 		val /= 100;
 		dev_dbg(priv->device, "set rx-delay to %x\n", val);
-		if (val <= SYSCON_ERXDC_MASK) {
-			reg &= ~(SYSCON_ERXDC_MASK << SYSCON_ERXDC_SHIFT);
+		if (val <= gmac->variant->rx_delay_max) {
+			reg &= ~(gmac->variant->rx_delay_max <<
+				 SYSCON_ERXDC_SHIFT);
 			reg |= (val << SYSCON_ERXDC_SHIFT);
 		} else {
 			dev_err(priv->device, "Invalid RX clock delay: %d\n",
-- 
2.17.0

[PATCH RESEND net-next v2 7/8] net: stmmac: dwmac-sun8i: Support different ranges for TX/RX delay chains

[Chen-Yu Tsai]

On the R40 SoC, the RX delay chain only has a range of 0~7 (hundred
picoseconds), instead of 0~31. Also the TX delay chain is completely
absent.

This patch adds support for different ranges by adding per-compatible
maximum values in the variant data. A maximum of 0 indicates that the
delay chain is not supported or absent.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 32 +++++++++++++------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
index 79e104a20e20..4f5612a3c855 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
@@ -47,6 +47,12 @@
  * @support_mii:		Does the MAC handle MII
  * @support_rmii:		Does the MAC handle RMII
  * @support_rgmii:		Does the MAC handle RGMII
+ *
+ * @rx_delay_max:		Maximum raw value for RX delay chain
+ * @tx_delay_max:		Maximum raw value for TX delay chain
+ *				These two also indicate the bitmask for
+ *				the RX and TX delay chain registers. A
+ *				value of zero indicates this is not supported.
  */
 struct emac_variant {
 	u32 default_syscon_value;
@@ -55,6 +61,8 @@ struct emac_variant {
 	bool support_mii;
 	bool support_rmii;
 	bool support_rgmii;
+	u8 rx_delay_max;
+	u8 tx_delay_max;
 };
 
 /* struct sunxi_priv_data - hold all sunxi private data
@@ -91,7 +99,9 @@ static const struct emac_variant emac_variant_h3 = {
 	.soc_has_internal_phy = true,
 	.support_mii = true,
 	.support_rmii = true,
-	.support_rgmii = true
+	.support_rgmii = true,
+	.rx_delay_max = 31,
+	.tx_delay_max = 7,
 };
 
 static const struct emac_variant emac_variant_v3s = {
@@ -106,7 +116,9 @@ static const struct emac_variant emac_variant_a83t = {
 	.syscon_field = &sun8i_syscon_reg_field,
 	.soc_has_internal_phy = false,
 	.support_mii = true,
-	.support_rgmii = true
+	.support_rgmii = true,
+	.rx_delay_max = 31,
+	.tx_delay_max = 7,
 };
 
 static const struct emac_variant emac_variant_a64 = {
@@ -115,7 +127,9 @@ static const struct emac_variant emac_variant_a64 = {
 	.soc_has_internal_phy = false,
 	.support_mii = true,
 	.support_rmii = true,
-	.support_rgmii = true
+	.support_rgmii = true,
+	.rx_delay_max = 31,
+	.tx_delay_max = 7,
 };
 
 #define EMAC_BASIC_CTL0 0x00
@@ -219,9 +233,7 @@ static const struct emac_variant emac_variant_a64 = {
 #define SYSCON_RMII_EN		BIT(13) /* 1: enable RMII (overrides EPIT) */
 
 /* Generic system control EMAC_CLK bits */
-#define SYSCON_ETXDC_MASK		GENMASK(2, 0)
 #define SYSCON_ETXDC_SHIFT		10
-#define SYSCON_ERXDC_MASK		GENMASK(4, 0)
 #define SYSCON_ERXDC_SHIFT		5
 /* EMAC PHY Interface Type */
 #define SYSCON_EPIT			BIT(2) /* 1: RGMII, 0: MII */
@@ -847,8 +859,9 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 		}
 		val /= 100;
 		dev_dbg(priv->device, "set tx-delay to %x\n", val);
-		if (val <= SYSCON_ETXDC_MASK) {
-			reg &= ~(SYSCON_ETXDC_MASK << SYSCON_ETXDC_SHIFT);
+		if (val <= gmac->variant->tx_delay_max) {
+			reg &= ~(gmac->variant->tx_delay_max <<
+				 SYSCON_ETXDC_SHIFT);
 			reg |= (val << SYSCON_ETXDC_SHIFT);
 		} else {
 			dev_err(priv->device, "Invalid TX clock delay: %d\n",
@@ -864,8 +877,9 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 		}
 		val /= 100;
 		dev_dbg(priv->device, "set rx-delay to %x\n", val);
-		if (val <= SYSCON_ERXDC_MASK) {
-			reg &= ~(SYSCON_ERXDC_MASK << SYSCON_ERXDC_SHIFT);
+		if (val <= gmac->variant->rx_delay_max) {
+			reg &= ~(gmac->variant->rx_delay_max <<
+				 SYSCON_ERXDC_SHIFT);
 			reg |= (val << SYSCON_ERXDC_SHIFT);
 		} else {
 			dev_err(priv->device, "Invalid RX clock delay: %d\n",
-- 
2.17.0

[PATCH RESEND net-next v2 8/8] net: stmmac: dwmac-sun8i: Add support for GMAC on Allwinner R40 SoC

[Chen-Yu Tsai]

The Allwinner R40 SoC has the EMAC controller supported by dwmac-sun8i.
It is named "GMAC", while EMAC refers to the 10/100 Mbps Ethernet
controller supported by sun4i-emac. The controller is the same, but
the R40 has the glue layer controls in the clock control unit (CCU),
with a reduced RX delay chain, and no TX delay chain.

This patch adds support for it using the framework laid out by previous
patches to map the differences.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c   | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
index 4f5612a3c855..2f7f0915f071 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
@@ -93,6 +93,13 @@ static const struct reg_field sun8i_syscon_reg_field = {
 	.msb = 31,
 };
 
+/* EMAC clock register @ 0x164 in the CCU address range */
+static const struct reg_field sun8i_ccu_reg_field = {
+	.reg = 0x164,
+	.lsb = 0,
+	.msb = 31,
+};
+
 static const struct emac_variant emac_variant_h3 = {
 	.default_syscon_value = 0x58000,
 	.syscon_field = &sun8i_syscon_reg_field,
@@ -121,6 +128,14 @@ static const struct emac_variant emac_variant_a83t = {
 	.tx_delay_max = 7,
 };
 
+static const struct emac_variant emac_variant_r40 = {
+	.default_syscon_value = 0,
+	.syscon_field = &sun8i_ccu_reg_field,
+	.support_mii = true,
+	.support_rgmii = true,
+	.rx_delay_max = 7,
+};
+
 static const struct emac_variant emac_variant_a64 = {
 	.default_syscon_value = 0,
 	.syscon_field = &sun8i_syscon_reg_field,
@@ -1160,6 +1175,8 @@ static const struct of_device_id sun8i_dwmac_match[] = {
 		.data = &emac_variant_v3s },
 	{ .compatible = "allwinner,sun8i-a83t-emac",
 		.data = &emac_variant_a83t },
+	{ .compatible = "allwinner,sun8i-r40-gmac",
+		.data = &emac_variant_r40 },
 	{ .compatible = "allwinner,sun50i-a64-emac",
 		.data = &emac_variant_a64 },
 	{ }
-- 
2.17.0

[PATCH RESEND net-next v2 8/8] net: stmmac: dwmac-sun8i: Add support for GMAC on Allwinner R40 SoC

[Chen-Yu Tsai]

The Allwinner R40 SoC has the EMAC controller supported by dwmac-sun8i.
It is named "GMAC", while EMAC refers to the 10/100 Mbps Ethernet
controller supported by sun4i-emac. The controller is the same, but
the R40 has the glue layer controls in the clock control unit (CCU),
with a reduced RX delay chain, and no TX delay chain.

This patch adds support for it using the framework laid out by previous
patches to map the differences.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c   | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
index 4f5612a3c855..2f7f0915f071 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
@@ -93,6 +93,13 @@ static const struct reg_field sun8i_syscon_reg_field = {
 	.msb = 31,
 };
 
+/* EMAC clock register @ 0x164 in the CCU address range */
+static const struct reg_field sun8i_ccu_reg_field = {
+	.reg = 0x164,
+	.lsb = 0,
+	.msb = 31,
+};
+
 static const struct emac_variant emac_variant_h3 = {
 	.default_syscon_value = 0x58000,
 	.syscon_field = &sun8i_syscon_reg_field,
@@ -121,6 +128,14 @@ static const struct emac_variant emac_variant_a83t = {
 	.tx_delay_max = 7,
 };
 
+static const struct emac_variant emac_variant_r40 = {
+	.default_syscon_value = 0,
+	.syscon_field = &sun8i_ccu_reg_field,
+	.support_mii = true,
+	.support_rgmii = true,
+	.rx_delay_max = 7,
+};
+
 static const struct emac_variant emac_variant_a64 = {
 	.default_syscon_value = 0,
 	.syscon_field = &sun8i_syscon_reg_field,
@@ -1160,6 +1175,8 @@ static const struct of_device_id sun8i_dwmac_match[] = {
 		.data = &emac_variant_v3s },
 	{ .compatible = "allwinner,sun8i-a83t-emac",
 		.data = &emac_variant_a83t },
+	{ .compatible = "allwinner,sun8i-r40-gmac",
+		.data = &emac_variant_r40 },
 	{ .compatible = "allwinner,sun50i-a64-emac",
 		.data = &emac_variant_a64 },
 	{ }
-- 
2.17.0

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Andrew Lunn]

On Mon, May 14, 2018 at 03:14:18AM +0800, Chen-Yu Tsai wrote:
> The clock delay chains found in the glue layer for dwmac-sun8i are only
> used with RGMII PHYs. They are not intended for non-RGMII PHYs, such as
> MII external PHYs or the internal PHY. Also, a recent SoC has a smaller
> range of possible values for the delay chain.
> 
> This patch reformats the delay chain section of the device tree binding
> to make it clear that the delay chains only apply to RGMII PHYs, and
> make it easier to add the R40-specific bits later.
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
> ---
>  Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
> index 3d6d5fa0c4d5..e04ce75e24a3 100644
> --- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
> +++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
> @@ -28,10 +28,13 @@ Required properties:
>    - allwinner,sun8i-a83t-system-controller
>  
>  Optional properties:
> -- allwinner,tx-delay-ps: TX clock delay chain value in ps. Range value is 0-700. Default is 0)
> -- allwinner,rx-delay-ps: RX clock delay chain value in ps. Range value is 0-3100. Default is 0)
> -Both delay properties need to be a multiple of 100. They control the delay for
> -external PHY.
> +- allwinner,tx-delay-ps: TX clock delay chain value in ps.
> +			 Range is 0-700. Default is 0.
> +- allwinner,rx-delay-ps: RX clock delay chain value in ps.
> +			 Range is 0-3100. Default is 0.
> +Both delay properties need to be a multiple of 100. They control the
> +clock delay for external RGMII PHY. They do not apply to the internal
> +PHY or external non-RGMII PHYs.

Hi Chen-Yu

Are these delays the MAC applies? Not the PHY. It would be good to
make it clear here these are MAC imposed delays.

     Andrew

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Andrew Lunn]

On Mon, May 14, 2018 at 03:14:18AM +0800, Chen-Yu Tsai wrote:
> The clock delay chains found in the glue layer for dwmac-sun8i are only
> used with RGMII PHYs. They are not intended for non-RGMII PHYs, such as
> MII external PHYs or the internal PHY. Also, a recent SoC has a smaller
> range of possible values for the delay chain.
> 
> This patch reformats the delay chain section of the device tree binding
> to make it clear that the delay chains only apply to RGMII PHYs, and
> make it easier to add the R40-specific bits later.
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
> ---
>  Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
> index 3d6d5fa0c4d5..e04ce75e24a3 100644
> --- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
> +++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
> @@ -28,10 +28,13 @@ Required properties:
>    - allwinner,sun8i-a83t-system-controller
>  
>  Optional properties:
> -- allwinner,tx-delay-ps: TX clock delay chain value in ps. Range value is 0-700. Default is 0)
> -- allwinner,rx-delay-ps: RX clock delay chain value in ps. Range value is 0-3100. Default is 0)
> -Both delay properties need to be a multiple of 100. They control the delay for
> -external PHY.
> +- allwinner,tx-delay-ps: TX clock delay chain value in ps.
> +			 Range is 0-700. Default is 0.
> +- allwinner,rx-delay-ps: RX clock delay chain value in ps.
> +			 Range is 0-3100. Default is 0.
> +Both delay properties need to be a multiple of 100. They control the
> +clock delay for external RGMII PHY. They do not apply to the internal
> +PHY or external non-RGMII PHYs.

Hi Chen-Yu

Are these delays the MAC applies? Not the PHY. It would be good to
make it clear here these are MAC imposed delays.

     Andrew

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Chen-Yu Tsai]

On Sun, May 13, 2018 at 12:49 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> On Mon, May 14, 2018 at 03:14:18AM +0800, Chen-Yu Tsai wrote:
>> The clock delay chains found in the glue layer for dwmac-sun8i are only
>> used with RGMII PHYs. They are not intended for non-RGMII PHYs, such as
>> MII external PHYs or the internal PHY. Also, a recent SoC has a smaller
>> range of possible values for the delay chain.
>>
>> This patch reformats the delay chain section of the device tree binding
>> to make it clear that the delay chains only apply to RGMII PHYs, and
>> make it easier to add the R40-specific bits later.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> Reviewed-by: Rob Herring <robh@kernel.org>
>> Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
>> ---
>>  Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 11 +++++++----
>>  1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
>> index 3d6d5fa0c4d5..e04ce75e24a3 100644
>> --- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
>> +++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
>> @@ -28,10 +28,13 @@ Required properties:
>>    - allwinner,sun8i-a83t-system-controller
>>
>>  Optional properties:
>> -- allwinner,tx-delay-ps: TX clock delay chain value in ps. Range value is 0-700. Default is 0)
>> -- allwinner,rx-delay-ps: RX clock delay chain value in ps. Range value is 0-3100. Default is 0)
>> -Both delay properties need to be a multiple of 100. They control the delay for
>> -external PHY.
>> +- allwinner,tx-delay-ps: TX clock delay chain value in ps.
>> +                      Range is 0-700. Default is 0.
>> +- allwinner,rx-delay-ps: RX clock delay chain value in ps.
>> +                      Range is 0-3100. Default is 0.
>> +Both delay properties need to be a multiple of 100. They control the
>> +clock delay for external RGMII PHY. They do not apply to the internal
>> +PHY or external non-RGMII PHYs.
>
> Hi Chen-Yu
>
> Are these delays the MAC applies? Not the PHY. It would be good to
> make it clear here these are MAC imposed delays.

Yes these are applied on the MAC side. Being described in the device
tree bindings for the MAC, I thought this was implied to be the case?
Are there known exceptions?

Thanks
ChenYu

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Chen-Yu Tsai]

On Sun, May 13, 2018 at 12:49 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> On Mon, May 14, 2018 at 03:14:18AM +0800, Chen-Yu Tsai wrote:
>> The clock delay chains found in the glue layer for dwmac-sun8i are only
>> used with RGMII PHYs. They are not intended for non-RGMII PHYs, such as
>> MII external PHYs or the internal PHY. Also, a recent SoC has a smaller
>> range of possible values for the delay chain.
>>
>> This patch reformats the delay chain section of the device tree binding
>> to make it clear that the delay chains only apply to RGMII PHYs, and
>> make it easier to add the R40-specific bits later.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> Reviewed-by: Rob Herring <robh@kernel.org>
>> Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
>> ---
>>  Documentation/devicetree/bindings/net/dwmac-sun8i.txt | 11 +++++++----
>>  1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
>> index 3d6d5fa0c4d5..e04ce75e24a3 100644
>> --- a/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
>> +++ b/Documentation/devicetree/bindings/net/dwmac-sun8i.txt
>> @@ -28,10 +28,13 @@ Required properties:
>>    - allwinner,sun8i-a83t-system-controller
>>
>>  Optional properties:
>> -- allwinner,tx-delay-ps: TX clock delay chain value in ps. Range value is 0-700. Default is 0)
>> -- allwinner,rx-delay-ps: RX clock delay chain value in ps. Range value is 0-3100. Default is 0)
>> -Both delay properties need to be a multiple of 100. They control the delay for
>> -external PHY.
>> +- allwinner,tx-delay-ps: TX clock delay chain value in ps.
>> +                      Range is 0-700. Default is 0.
>> +- allwinner,rx-delay-ps: RX clock delay chain value in ps.
>> +                      Range is 0-3100. Default is 0.
>> +Both delay properties need to be a multiple of 100. They control the
>> +clock delay for external RGMII PHY. They do not apply to the internal
>> +PHY or external non-RGMII PHYs.
>
> Hi Chen-Yu
>
> Are these delays the MAC applies? Not the PHY. It would be good to
> make it clear here these are MAC imposed delays.

Yes these are applied on the MAC side. Being described in the device
tree bindings for the MAC, I thought this was implied to be the case?
Are there known exceptions?

Thanks
ChenYu

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Andrew Lunn]

> > Hi Chen-Yu
> >
> > Are these delays the MAC applies? Not the PHY. It would be good to
> > make it clear here these are MAC imposed delays.
> 
> Yes these are applied on the MAC side. Being described in the device
> tree bindings for the MAC, I thought this was implied to be the case?
> Are there known exceptions?

There is frequent confusion with this. Most of the time, the PHY does
the delay, not the MAC, based on the phy-mode. So the MAC doing it is
an exception in itself.

Do you actually need these delays for the board you adding support
for? Does the PHY not support adding the needed delays? If you don't
need the delays, i would not even implement them.

    Andrew

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Andrew Lunn]

> > Hi Chen-Yu
> >
> > Are these delays the MAC applies? Not the PHY. It would be good to
> > make it clear here these are MAC imposed delays.
> 
> Yes these are applied on the MAC side. Being described in the device
> tree bindings for the MAC, I thought this was implied to be the case?
> Are there known exceptions?

There is frequent confusion with this. Most of the time, the PHY does
the delay, not the MAC, based on the phy-mode. So the MAC doing it is
an exception in itself.

Do you actually need these delays for the board you adding support
for? Does the PHY not support adding the needed delays? If you don't
need the delays, i would not even implement them.

    Andrew

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Icenowy Zheng]

于 2018年5月14日 GMT+08:00 上午4:05:29, Andrew Lunn <andrew@lunn.ch> 写到:
>> > Hi Chen-Yu
>> >
>> > Are these delays the MAC applies? Not the PHY. It would be good to
>> > make it clear here these are MAC imposed delays.
>> 
>> Yes these are applied on the MAC side. Being described in the device
>> tree bindings for the MAC, I thought this was implied to be the case?
>> Are there known exceptions?
>
>There is frequent confusion with this. Most of the time, the PHY does
>the delay, not the MAC, based on the phy-mode. So the MAC doing it is
>an exception in itself.
>
>Do you actually need these delays for the board you adding support
>for? Does the PHY not support adding the needed delays? If you don't
>need the delays, i would not even implement them.

They are needed if the rx/tx have not equal length.

For several boards if the delay is not present, the network
is unusable. (I have at least met this on Banana Pi M3, an
Allwinner A83T SBC w/ RTL8211E)

>
>    Andrew
>
>_______________________________________________
>linux-arm-kernel mailing list
>linux-arm-kernel@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Icenowy Zheng]

于 2018年5月14日 GMT+08:00 上午4:05:29, Andrew Lunn <andrew@lunn.ch> 写到:
>> > Hi Chen-Yu
>> >
>> > Are these delays the MAC applies? Not the PHY. It would be good to
>> > make it clear here these are MAC imposed delays.
>> 
>> Yes these are applied on the MAC side. Being described in the device
>> tree bindings for the MAC, I thought this was implied to be the case?
>> Are there known exceptions?
>
>There is frequent confusion with this. Most of the time, the PHY does
>the delay, not the MAC, based on the phy-mode. So the MAC doing it is
>an exception in itself.
>
>Do you actually need these delays for the board you adding support
>for? Does the PHY not support adding the needed delays? If you don't
>need the delays, i would not even implement them.

They are needed if the rx/tx have not equal length.

For several boards if the delay is not present, the network
is unusable. (I have at least met this on Banana Pi M3, an
Allwinner A83T SBC w/ RTL8211E)

>
>    Andrew
>
>_______________________________________________
>linux-arm-kernel mailing list
>linux-arm-kernel@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Icenowy Zheng]

? 2018?5?14? GMT+08:00 ??4:05:29, Andrew Lunn <andrew@lunn.ch> ??:
>> > Hi Chen-Yu
>> >
>> > Are these delays the MAC applies? Not the PHY. It would be good to
>> > make it clear here these are MAC imposed delays.
>> 
>> Yes these are applied on the MAC side. Being described in the device
>> tree bindings for the MAC, I thought this was implied to be the case?
>> Are there known exceptions?
>
>There is frequent confusion with this. Most of the time, the PHY does
>the delay, not the MAC, based on the phy-mode. So the MAC doing it is
>an exception in itself.
>
>Do you actually need these delays for the board you adding support
>for? Does the PHY not support adding the needed delays? If you don't
>need the delays, i would not even implement them.

They are needed if the rx/tx have not equal length.

For several boards if the delay is not present, the network
is unusable. (I have at least met this on Banana Pi M3, an
Allwinner A83T SBC w/ RTL8211E)

>
>    Andrew
>
>_______________________________________________
>linux-arm-kernel mailing list
>linux-arm-kernel at lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Chen-Yu Tsai]

On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>> > Hi Chen-Yu
>> >
>> > Are these delays the MAC applies? Not the PHY. It would be good to
>> > make it clear here these are MAC imposed delays.
>>
>> Yes these are applied on the MAC side. Being described in the device
>> tree bindings for the MAC, I thought this was implied to be the case?
>> Are there known exceptions?
>
> There is frequent confusion with this. Most of the time, the PHY does
> the delay, not the MAC, based on the phy-mode. So the MAC doing it is
> an exception in itself.
>
> Do you actually need these delays for the board you adding support
> for? Does the PHY not support adding the needed delays? If you don't
> need the delays, i would not even implement them.

Yes this is already used on the Bananapi M3. This patch merely reformats
the description and adds a note saying this only applies to RGMII mode.

ChenYu

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Chen-Yu Tsai]

On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>> > Hi Chen-Yu
>> >
>> > Are these delays the MAC applies? Not the PHY. It would be good to
>> > make it clear here these are MAC imposed delays.
>>
>> Yes these are applied on the MAC side. Being described in the device
>> tree bindings for the MAC, I thought this was implied to be the case?
>> Are there known exceptions?
>
> There is frequent confusion with this. Most of the time, the PHY does
> the delay, not the MAC, based on the phy-mode. So the MAC doing it is
> an exception in itself.
>
> Do you actually need these delays for the board you adding support
> for? Does the PHY not support adding the needed delays? If you don't
> need the delays, i would not even implement them.

Yes this is already used on the Bananapi M3. This patch merely reformats
the description and adds a note saying this only applies to RGMII mode.

ChenYu

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Andrew Lunn]

On Mon, May 14, 2018 at 04:10:58AM +0800, Icenowy Zheng wrote:
> 
> 
> 于 2018年5月14日 GMT+08:00 上午4:05:29, Andrew Lunn <andrew@lunn.ch> 写到:
> >> > Hi Chen-Yu
> >> >
> >> > Are these delays the MAC applies? Not the PHY. It would be good to
> >> > make it clear here these are MAC imposed delays.
> >> 
> >> Yes these are applied on the MAC side. Being described in the device
> >> tree bindings for the MAC, I thought this was implied to be the case?
> >> Are there known exceptions?
> >
> >There is frequent confusion with this. Most of the time, the PHY does
> >the delay, not the MAC, based on the phy-mode. So the MAC doing it is
> >an exception in itself.
> >
> >Do you actually need these delays for the board you adding support
> >for? Does the PHY not support adding the needed delays? If you don't
> >need the delays, i would not even implement them.
> 
> They are needed if the rx/tx have not equal length.
> 

> For several boards if the delay is not present, the network
> is unusable. (I have at least met this on Banana Pi M3, an
> Allwinner A83T SBC w/ RTL8211E)

The RTL8211E does not appear to support adding delays, via
registers. You can do it with strapping resistors. The RTL8211F does
support delays via a register. So for the Banana Pi M3 it is
justified.

However, in general, i would recommend letting the PHY do it, if it
can.

	Andrew

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Andrew Lunn]

On Mon, May 14, 2018 at 04:10:58AM +0800, Icenowy Zheng wrote:
> 
> 
> ? 2018?5?14? GMT+08:00 ??4:05:29, Andrew Lunn <andrew@lunn.ch> ??:
> >> > Hi Chen-Yu
> >> >
> >> > Are these delays the MAC applies? Not the PHY. It would be good to
> >> > make it clear here these are MAC imposed delays.
> >> 
> >> Yes these are applied on the MAC side. Being described in the device
> >> tree bindings for the MAC, I thought this was implied to be the case?
> >> Are there known exceptions?
> >
> >There is frequent confusion with this. Most of the time, the PHY does
> >the delay, not the MAC, based on the phy-mode. So the MAC doing it is
> >an exception in itself.
> >
> >Do you actually need these delays for the board you adding support
> >for? Does the PHY not support adding the needed delays? If you don't
> >need the delays, i would not even implement them.
> 
> They are needed if the rx/tx have not equal length.
> 

> For several boards if the delay is not present, the network
> is unusable. (I have at least met this on Banana Pi M3, an
> Allwinner A83T SBC w/ RTL8211E)

The RTL8211E does not appear to support adding delays, via
registers. You can do it with strapping resistors. The RTL8211F does
support delays via a register. So for the Banana Pi M3 it is
justified.

However, in general, i would recommend letting the PHY do it, if it
can.

	Andrew

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Andrew Lunn]

On Sun, May 13, 2018 at 01:11:08PM -0700, Chen-Yu Tsai wrote:
> On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> >> > Hi Chen-Yu
> >> >
> >> > Are these delays the MAC applies? Not the PHY. It would be good to
> >> > make it clear here these are MAC imposed delays.
> >>
> >> Yes these are applied on the MAC side. Being described in the device
> >> tree bindings for the MAC, I thought this was implied to be the case?
> >> Are there known exceptions?
> >
> > There is frequent confusion with this. Most of the time, the PHY does
> > the delay, not the MAC, based on the phy-mode. So the MAC doing it is
> > an exception in itself.
> >
> > Do you actually need these delays for the board you adding support
> > for? Does the PHY not support adding the needed delays? If you don't
> > need the delays, i would not even implement them.
> 
> Yes this is already used on the Bananapi M3. This patch merely reformats
> the description and adds a note saying this only applies to RGMII mode.

Yes, the current code is needed for the Bananapi M3. But you have
another patch which extends the code to support a smaller range. Do
you have a board which actually needs this? If not, i would not add
that new code.

     Andrew

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Andrew Lunn]

On Sun, May 13, 2018 at 01:11:08PM -0700, Chen-Yu Tsai wrote:
> On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> >> > Hi Chen-Yu
> >> >
> >> > Are these delays the MAC applies? Not the PHY. It would be good to
> >> > make it clear here these are MAC imposed delays.
> >>
> >> Yes these are applied on the MAC side. Being described in the device
> >> tree bindings for the MAC, I thought this was implied to be the case?
> >> Are there known exceptions?
> >
> > There is frequent confusion with this. Most of the time, the PHY does
> > the delay, not the MAC, based on the phy-mode. So the MAC doing it is
> > an exception in itself.
> >
> > Do you actually need these delays for the board you adding support
> > for? Does the PHY not support adding the needed delays? If you don't
> > need the delays, i would not even implement them.
> 
> Yes this is already used on the Bananapi M3. This patch merely reformats
> the description and adds a note saying this only applies to RGMII mode.

Yes, the current code is needed for the Bananapi M3. But you have
another patch which extends the code to support a smaller range. Do
you have a board which actually needs this? If not, i would not add
that new code.

     Andrew

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Chen-Yu Tsai]

On Sun, May 13, 2018 at 1:29 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> On Sun, May 13, 2018 at 01:11:08PM -0700, Chen-Yu Tsai wrote:
>> On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>> >> > Hi Chen-Yu
>> >> >
>> >> > Are these delays the MAC applies? Not the PHY. It would be good to
>> >> > make it clear here these are MAC imposed delays.
>> >>
>> >> Yes these are applied on the MAC side. Being described in the device
>> >> tree bindings for the MAC, I thought this was implied to be the case?
>> >> Are there known exceptions?
>> >
>> > There is frequent confusion with this. Most of the time, the PHY does
>> > the delay, not the MAC, based on the phy-mode. So the MAC doing it is
>> > an exception in itself.
>> >
>> > Do you actually need these delays for the board you adding support
>> > for? Does the PHY not support adding the needed delays? If you don't
>> > need the delays, i would not even implement them.
>>
>> Yes this is already used on the Bananapi M3. This patch merely reformats
>> the description and adds a note saying this only applies to RGMII mode.
>
> Yes, the current code is needed for the Bananapi M3. But you have
> another patch which extends the code to support a smaller range. Do
> you have a board which actually needs this? If not, i would not add
> that new code.

IIRC the delay on the PHY side is either 2ns or none. The delay on the
MAC side here is an order smaller, likely fine tuning to cope with board
design deficiencies.

Currently no other board requires this, but this is already part of the
binding. The new stuff limits the range for a specific SoC, simply because
that is the range supported by the control register. Not implementing, i.e.
supporting the whole range from the property, which might get truncated,
doesn't make much sense to me.

Regards
ChenYu

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Chen-Yu Tsai]

On Sun, May 13, 2018 at 1:29 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> On Sun, May 13, 2018 at 01:11:08PM -0700, Chen-Yu Tsai wrote:
>> On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>> >> > Hi Chen-Yu
>> >> >
>> >> > Are these delays the MAC applies? Not the PHY. It would be good to
>> >> > make it clear here these are MAC imposed delays.
>> >>
>> >> Yes these are applied on the MAC side. Being described in the device
>> >> tree bindings for the MAC, I thought this was implied to be the case?
>> >> Are there known exceptions?
>> >
>> > There is frequent confusion with this. Most of the time, the PHY does
>> > the delay, not the MAC, based on the phy-mode. So the MAC doing it is
>> > an exception in itself.
>> >
>> > Do you actually need these delays for the board you adding support
>> > for? Does the PHY not support adding the needed delays? If you don't
>> > need the delays, i would not even implement them.
>>
>> Yes this is already used on the Bananapi M3. This patch merely reformats
>> the description and adds a note saying this only applies to RGMII mode.
>
> Yes, the current code is needed for the Bananapi M3. But you have
> another patch which extends the code to support a smaller range. Do
> you have a board which actually needs this? If not, i would not add
> that new code.

IIRC the delay on the PHY side is either 2ns or none. The delay on the
MAC side here is an order smaller, likely fine tuning to cope with board
design deficiencies.

Currently no other board requires this, but this is already part of the
binding. The new stuff limits the range for a specific SoC, simply because
that is the range supported by the control register. Not implementing, i.e.
supporting the whole range from the property, which might get truncated,
doesn't make much sense to me.

Regards
ChenYu

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Icenowy Zheng]

于 2018年5月14日 GMT+08:00 下午12:59:22, Chen-Yu Tsai <wens@csie.org> 写到:
>On Sun, May 13, 2018 at 1:29 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>> On Sun, May 13, 2018 at 01:11:08PM -0700, Chen-Yu Tsai wrote:
>>> On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>>> >> > Hi Chen-Yu
>>> >> >
>>> >> > Are these delays the MAC applies? Not the PHY. It would be good
>to
>>> >> > make it clear here these are MAC imposed delays.
>>> >>
>>> >> Yes these are applied on the MAC side. Being described in the
>device
>>> >> tree bindings for the MAC, I thought this was implied to be the
>case?
>>> >> Are there known exceptions?
>>> >
>>> > There is frequent confusion with this. Most of the time, the PHY
>does
>>> > the delay, not the MAC, based on the phy-mode. So the MAC doing it
>is
>>> > an exception in itself.
>>> >
>>> > Do you actually need these delays for the board you adding support
>>> > for? Does the PHY not support adding the needed delays? If you
>don't
>>> > need the delays, i would not even implement them.
>>>
>>> Yes this is already used on the Bananapi M3. This patch merely
>reformats
>>> the description and adds a note saying this only applies to RGMII
>mode.
>>
>> Yes, the current code is needed for the Bananapi M3. But you have
>> another patch which extends the code to support a smaller range. Do
>> you have a board which actually needs this? If not, i would not add
>> that new code.
>
>IIRC the delay on the PHY side is either 2ns or none. The delay on the
>MAC side here is an order smaller, likely fine tuning to cope with
>board
>design deficiencies.

And the weird thing is that the delay fails to work on some batches
of RTL8211E, notably many cases are shown on Pine A64+
board.

P.S. The delay is intended to be set via wires on PCB, other than
by software. Although Realtek provided some magic numbers
to Pine64, in order to fix the network problem due to PHY
delay failure.

>
>Currently no other board requires this, but this is already part of the
>binding. The new stuff limits the range for a specific SoC, simply
>because
>that is the range supported by the control register. Not implementing,
>i.e.
>supporting the whole range from the property, which might get
>truncated,
>doesn't make much sense to me.
>
>Regards
>ChenYu
>
>_______________________________________________
>linux-arm-kernel mailing list
>linux-arm-kernel@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Icenowy Zheng]

于 2018年5月14日 GMT+08:00 下午12:59:22, Chen-Yu Tsai <wens@csie.org> 写到:
>On Sun, May 13, 2018 at 1:29 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>> On Sun, May 13, 2018 at 01:11:08PM -0700, Chen-Yu Tsai wrote:
>>> On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>>> >> > Hi Chen-Yu
>>> >> >
>>> >> > Are these delays the MAC applies? Not the PHY. It would be good
>to
>>> >> > make it clear here these are MAC imposed delays.
>>> >>
>>> >> Yes these are applied on the MAC side. Being described in the
>device
>>> >> tree bindings for the MAC, I thought this was implied to be the
>case?
>>> >> Are there known exceptions?
>>> >
>>> > There is frequent confusion with this. Most of the time, the PHY
>does
>>> > the delay, not the MAC, based on the phy-mode. So the MAC doing it
>is
>>> > an exception in itself.
>>> >
>>> > Do you actually need these delays for the board you adding support
>>> > for? Does the PHY not support adding the needed delays? If you
>don't
>>> > need the delays, i would not even implement them.
>>>
>>> Yes this is already used on the Bananapi M3. This patch merely
>reformats
>>> the description and adds a note saying this only applies to RGMII
>mode.
>>
>> Yes, the current code is needed for the Bananapi M3. But you have
>> another patch which extends the code to support a smaller range. Do
>> you have a board which actually needs this? If not, i would not add
>> that new code.
>
>IIRC the delay on the PHY side is either 2ns or none. The delay on the
>MAC side here is an order smaller, likely fine tuning to cope with
>board
>design deficiencies.

And the weird thing is that the delay fails to work on some batches
of RTL8211E, notably many cases are shown on Pine A64+
board.

P.S. The delay is intended to be set via wires on PCB, other than
by software. Although Realtek provided some magic numbers
to Pine64, in order to fix the network problem due to PHY
delay failure.

>
>Currently no other board requires this, but this is already part of the
>binding. The new stuff limits the range for a specific SoC, simply
>because
>that is the range supported by the control register. Not implementing,
>i.e.
>supporting the whole range from the property, which might get
>truncated,
>doesn't make much sense to me.
>
>Regards
>ChenYu
>
>_______________________________________________
>linux-arm-kernel mailing list
>linux-arm-kernel@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Icenowy Zheng]

? 2018?5?14? GMT+08:00 ??12:59:22, Chen-Yu Tsai <wens@csie.org> ??:
>On Sun, May 13, 2018 at 1:29 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>> On Sun, May 13, 2018 at 01:11:08PM -0700, Chen-Yu Tsai wrote:
>>> On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>>> >> > Hi Chen-Yu
>>> >> >
>>> >> > Are these delays the MAC applies? Not the PHY. It would be good
>to
>>> >> > make it clear here these are MAC imposed delays.
>>> >>
>>> >> Yes these are applied on the MAC side. Being described in the
>device
>>> >> tree bindings for the MAC, I thought this was implied to be the
>case?
>>> >> Are there known exceptions?
>>> >
>>> > There is frequent confusion with this. Most of the time, the PHY
>does
>>> > the delay, not the MAC, based on the phy-mode. So the MAC doing it
>is
>>> > an exception in itself.
>>> >
>>> > Do you actually need these delays for the board you adding support
>>> > for? Does the PHY not support adding the needed delays? If you
>don't
>>> > need the delays, i would not even implement them.
>>>
>>> Yes this is already used on the Bananapi M3. This patch merely
>reformats
>>> the description and adds a note saying this only applies to RGMII
>mode.
>>
>> Yes, the current code is needed for the Bananapi M3. But you have
>> another patch which extends the code to support a smaller range. Do
>> you have a board which actually needs this? If not, i would not add
>> that new code.
>
>IIRC the delay on the PHY side is either 2ns or none. The delay on the
>MAC side here is an order smaller, likely fine tuning to cope with
>board
>design deficiencies.

And the weird thing is that the delay fails to work on some batches
of RTL8211E, notably many cases are shown on Pine A64+
board.

P.S. The delay is intended to be set via wires on PCB, other than
by software. Although Realtek provided some magic numbers
to Pine64, in order to fix the network problem due to PHY
delay failure.

>
>Currently no other board requires this, but this is already part of the
>binding. The new stuff limits the range for a specific SoC, simply
>because
>that is the range supported by the control register. Not implementing,
>i.e.
>supporting the whole range from the property, which might get
>truncated,
>doesn't make much sense to me.
>
>Regards
>ChenYu
>
>_______________________________________________
>linux-arm-kernel mailing list
>linux-arm-kernel at lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 2333 bytes --]

On Sun, May 13, 2018 at 09:59:22PM -0700, Chen-Yu Tsai wrote:
> On Sun, May 13, 2018 at 1:29 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> > On Sun, May 13, 2018 at 01:11:08PM -0700, Chen-Yu Tsai wrote:
> >> On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> >> >> > Hi Chen-Yu
> >> >> >
> >> >> > Are these delays the MAC applies? Not the PHY. It would be good to
> >> >> > make it clear here these are MAC imposed delays.
> >> >>
> >> >> Yes these are applied on the MAC side. Being described in the device
> >> >> tree bindings for the MAC, I thought this was implied to be the case?
> >> >> Are there known exceptions?
> >> >
> >> > There is frequent confusion with this. Most of the time, the PHY does
> >> > the delay, not the MAC, based on the phy-mode. So the MAC doing it is
> >> > an exception in itself.
> >> >
> >> > Do you actually need these delays for the board you adding support
> >> > for? Does the PHY not support adding the needed delays? If you don't
> >> > need the delays, i would not even implement them.
> >>
> >> Yes this is already used on the Bananapi M3. This patch merely reformats
> >> the description and adds a note saying this only applies to RGMII mode.
> >
> > Yes, the current code is needed for the Bananapi M3. But you have
> > another patch which extends the code to support a smaller range. Do
> > you have a board which actually needs this? If not, i would not add
> > that new code.
> 
> IIRC the delay on the PHY side is either 2ns or none. The delay on the
> MAC side here is an order smaller, likely fine tuning to cope with board
> design deficiencies.
> 
> Currently no other board requires this, but this is already part of the
> binding. The new stuff limits the range for a specific SoC, simply because
> that is the range supported by the control register. Not implementing, i.e.
> supporting the whole range from the property, which might get truncated,
> doesn't make much sense to me.

With that driver we don't, but the previous design had the same
feature and it was used on more boards. It was simply initialized
statically in U-Boot, and not in Linux through the DT like it is done
here.

Maxime

-- 
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com

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[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Maxime Ripard]

On Sun, May 13, 2018 at 09:59:22PM -0700, Chen-Yu Tsai wrote:
> On Sun, May 13, 2018 at 1:29 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> > On Sun, May 13, 2018 at 01:11:08PM -0700, Chen-Yu Tsai wrote:
> >> On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> >> >> > Hi Chen-Yu
> >> >> >
> >> >> > Are these delays the MAC applies? Not the PHY. It would be good to
> >> >> > make it clear here these are MAC imposed delays.
> >> >>
> >> >> Yes these are applied on the MAC side. Being described in the device
> >> >> tree bindings for the MAC, I thought this was implied to be the case?
> >> >> Are there known exceptions?
> >> >
> >> > There is frequent confusion with this. Most of the time, the PHY does
> >> > the delay, not the MAC, based on the phy-mode. So the MAC doing it is
> >> > an exception in itself.
> >> >
> >> > Do you actually need these delays for the board you adding support
> >> > for? Does the PHY not support adding the needed delays? If you don't
> >> > need the delays, i would not even implement them.
> >>
> >> Yes this is already used on the Bananapi M3. This patch merely reformats
> >> the description and adds a note saying this only applies to RGMII mode.
> >
> > Yes, the current code is needed for the Bananapi M3. But you have
> > another patch which extends the code to support a smaller range. Do
> > you have a board which actually needs this? If not, i would not add
> > that new code.
> 
> IIRC the delay on the PHY side is either 2ns or none. The delay on the
> MAC side here is an order smaller, likely fine tuning to cope with board
> design deficiencies.
> 
> Currently no other board requires this, but this is already part of the
> binding. The new stuff limits the range for a specific SoC, simply because
> that is the range supported by the control register. Not implementing, i.e.
> supporting the whole range from the property, which might get truncated,
> doesn't make much sense to me.

With that driver we don't, but the previous design had the same
feature and it was used on more boards. It was simply initialized
statically in U-Boot, and not in Linux through the DT like it is done
here.

Maxime

-- 
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
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Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Andrew Lunn]

> > Currently no other board requires this, but this is already part of the
> > binding. The new stuff limits the range for a specific SoC, simply because
> > that is the range supported by the control register. Not implementing, i.e.
> > supporting the whole range from the property, which might get truncated,
> > doesn't make much sense to me.
> 
> With that driver we don't, but the previous design had the same
> feature and it was used on more boards. It was simply initialized
> statically in U-Boot, and not in Linux through the DT like it is done
> here.

If there are boards which do need it, then i'm fine with it. I would
also prefer that Linux does set it, and don't rely on U-boot.

   Andrew

[PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Andrew Lunn]

> > Currently no other board requires this, but this is already part of the
> > binding. The new stuff limits the range for a specific SoC, simply because
> > that is the range supported by the control register. Not implementing, i.e.
> > supporting the whole range from the property, which might get truncated,
> > doesn't make much sense to me.
> 
> With that driver we don't, but the previous design had the same
> feature and it was used on more boards. It was simply initialized
> statically in U-Boot, and not in Linux through the DT like it is done
> here.

If there are boards which do need it, then i'm fine with it. I would
also prefer that Linux does set it, and don't rely on U-boot.

   Andrew

Re: [PATCH RESEND net-next v2 0/8] net: stmmac: dwmac-sun8i: Support R40

[David Miller]

From: Chen-Yu Tsai <wens@csie.org>
Date: Mon, 14 May 2018 03:14:17 +0800

> This is a resend of the patches for net-next split out from my R40
> Ethernet support v2 series, as requested by David Miller. The arm-soc
> bits will follow, once I rework the A64 system controller compatible.

Series applied, but please continue to follow-up with Andrew Lunn about
how best to handle these RX and TX delays.

Thank you.

[PATCH RESEND net-next v2 0/8] net: stmmac: dwmac-sun8i: Support R40

[David Miller]

From: Chen-Yu Tsai <wens@csie.org>
Date: Mon, 14 May 2018 03:14:17 +0800

> This is a resend of the patches for net-next split out from my R40
> Ethernet support v2 series, as requested by David Miller. The arm-soc
> bits will follow, once I rework the A64 system controller compatible.

Series applied, but please continue to follow-up with Andrew Lunn about
how best to handle these RX and TX delays.

Thank you.