[PATCH net-next v2 0/2] axienet clock additions

[PATCH net-next v2 0/2] axienet clock additions

[Robert Hancock]

Add support to the axienet driver for controlling all of the clocks that
the logic core may utilize.

Note this patch set is dependent on "net: axienet: Fix probe error cleanup"
which has been submitted for the net tree.

Changed since v1:
-Clarified clock usages in documentation and code comments

Robert Hancock (2):
  dt-bindings: net: xilinx_axienet: Document additional clocks
  net: axienet: Enable more clocks

 .../bindings/net/xilinx_axienet.txt           | 25 ++++++++++----
 drivers/net/ethernet/xilinx/xilinx_axienet.h  |  8 +++--
 .../net/ethernet/xilinx/xilinx_axienet_main.c | 34 +++++++++++++++----
 .../net/ethernet/xilinx/xilinx_axienet_mdio.c |  4 +--
 4 files changed, 54 insertions(+), 17 deletions(-)

-- 
2.27.0

[PATCH net-next v2 1/2] dt-bindings: net: xilinx_axienet: Document additional clocks

[Robert Hancock]

Update DT bindings to describe all of the clocks that the axienet
driver will now be able to make use of.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 .../bindings/net/xilinx_axienet.txt           | 25 ++++++++++++++-----
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/xilinx_axienet.txt b/Documentation/devicetree/bindings/net/xilinx_axienet.txt
index 2cd452419ed0..5df5ba449b8f 100644
--- a/Documentation/devicetree/bindings/net/xilinx_axienet.txt
+++ b/Documentation/devicetree/bindings/net/xilinx_axienet.txt
@@ -42,11 +42,23 @@ Optional properties:
 		  support both 1000BaseX and SGMII modes. If set, the phy-mode
 		  should be set to match the mode selected on core reset (i.e.
 		  by the basex_or_sgmii core input line).
-- clocks	: AXI bus clock for the device. Refer to common clock bindings.
-		  Used to calculate MDIO clock divisor. If not specified, it is
-		  auto-detected from the CPU clock (but only on platforms where
-		  this is possible). New device trees should specify this - the
-		  auto detection is only for backward compatibility.
+- clock-names: 	  Tuple listing input clock names. Possible clocks:
+		  s_axi_lite_clk: Clock for AXI register slave interface
+		  axis_clk: AXI stream clock for DMA block
+		  ref_clk: Ethernet reference clock, used by signal delay
+			   primitives and transceivers
+		  mgt_clk: MGT reference clock (used by optional internal
+			   PCS/PMA PHY)
+
+		  Note that if s_axi_lite_clk is not specified by name, the
+		  first clock of any name is used for this. If that is also not
+		  specified, the clock rate is auto-detected from the CPU clock
+		  (but only on platforms where this is possible). New device
+		  trees should specify all applicable clocks by name - the
+		  fallbacks to an unnamed clock or to CPU clock are only for
+		  backward compatibility.
+- clocks: 	  Phandles to input clocks matching clock-names. Refer to common
+		  clock bindings.
 - axistream-connected: Reference to another node which contains the resources
 		       for the AXI DMA controller used by this device.
 		       If this is specified, the DMA-related resources from that
@@ -62,7 +74,8 @@ Example:
 		device_type = "network";
 		interrupt-parent = <&microblaze_0_axi_intc>;
 		interrupts = <2 0 1>;
-		clocks = <&axi_clk>;
+		clock-names = "s_axi_lite_clk", "axis_clk", "ref_clk", "mgt_clk";
+		clocks = <&axi_clk>, <&axi_clk>, <&pl_enet_ref_clk>, <&mgt_clk>;
 		phy-mode = "mii";
 		reg = <0x40c00000 0x40000 0x50c00000 0x40000>;
 		xlnx,rxcsum = <0x2>;
-- 
2.27.0

[PATCH net-next v2 2/2] net: axienet: Enable more clocks

[Robert Hancock]

This driver was only enabling the first clock on the device, regardless
of its name. However, this controller logic can have multiple clocks
which should all be enabled. Add support for enabling additional clocks.
The clock names used are matching those used in the Xilinx version of this
driver as well as the Xilinx device tree generator, except for mgt_clk
which is not present there.

For backward compatibility, if no named clocks are present, the first
clock present is used for determining the MDIO bus clock divider.

Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 drivers/net/ethernet/xilinx/xilinx_axienet.h  |  8 +++--
 .../net/ethernet/xilinx/xilinx_axienet_main.c | 34 +++++++++++++++----
 .../net/ethernet/xilinx/xilinx_axienet_mdio.c |  4 +--
 3 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet.h b/drivers/net/ethernet/xilinx/xilinx_axienet.h
index 1e966a39967e..708769349f76 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet.h
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h
@@ -376,6 +376,8 @@ struct axidma_bd {
 	struct sk_buff *skb;
 } __aligned(XAXIDMA_BD_MINIMUM_ALIGNMENT);
 
+#define XAE_NUM_MISC_CLOCKS 3
+
 /**
  * struct axienet_local - axienet private per device data
  * @ndev:	Pointer for net_device to which it will be attached.
@@ -385,7 +387,8 @@ struct axidma_bd {
  * @phylink_config: phylink configuration settings
  * @pcs_phy:	Reference to PCS/PMA PHY if used
  * @switch_x_sgmii: Whether switchable 1000BaseX/SGMII mode is enabled in the core
- * @clk:	Clock for AXI bus
+ * @axi_clk:	AXI4-Lite bus clock
+ * @misc_clks:	Misc ethernet clocks (AXI4-Stream, Ref, MGT clocks)
  * @mii_bus:	Pointer to MII bus structure
  * @mii_clk_div: MII bus clock divider value
  * @regs_start: Resource start for axienet device addresses
@@ -434,7 +437,8 @@ struct axienet_local {
 
 	bool switch_x_sgmii;
 
-	struct clk *clk;
+	struct clk *axi_clk;
+	struct clk_bulk_data misc_clks[XAE_NUM_MISC_CLOCKS];
 
 	struct mii_bus *mii_bus;
 	u8 mii_clk_div;
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index 5d677db0aee5..9635101fbb88 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -1863,17 +1863,35 @@ static int axienet_probe(struct platform_device *pdev)
 	lp->rx_bd_num = RX_BD_NUM_DEFAULT;
 	lp->tx_bd_num = TX_BD_NUM_DEFAULT;
 
-	lp->clk = devm_clk_get_optional(&pdev->dev, NULL);
-	if (IS_ERR(lp->clk)) {
-		ret = PTR_ERR(lp->clk);
+	lp->axi_clk = devm_clk_get_optional(&pdev->dev, "s_axi_lite_clk");
+	if (!lp->axi_clk) {
+		/* For backward compatibility, if named AXI clock is not present,
+		 * treat the first clock specified as the AXI clock.
+		 */
+		lp->axi_clk = devm_clk_get_optional(&pdev->dev, NULL);
+	}
+	if (IS_ERR(lp->axi_clk)) {
+		ret = PTR_ERR(lp->axi_clk);
 		goto free_netdev;
 	}
-	ret = clk_prepare_enable(lp->clk);
+	ret = clk_prepare_enable(lp->axi_clk);
 	if (ret) {
-		dev_err(&pdev->dev, "Unable to enable clock: %d\n", ret);
+		dev_err(&pdev->dev, "Unable to enable AXI clock: %d\n", ret);
 		goto free_netdev;
 	}
 
+	lp->misc_clks[0].id = "axis_clk";
+	lp->misc_clks[1].id = "ref_clk";
+	lp->misc_clks[2].id = "mgt_clk";
+
+	ret = devm_clk_bulk_get_optional(&pdev->dev, XAE_NUM_MISC_CLOCKS, lp->misc_clks);
+	if (ret)
+		goto cleanup_clk;
+
+	ret = clk_bulk_prepare_enable(XAE_NUM_MISC_CLOCKS, lp->misc_clks);
+	if (ret)
+		goto cleanup_clk;
+
 	/* Map device registers */
 	ethres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	lp->regs = devm_ioremap_resource(&pdev->dev, ethres);
@@ -2109,7 +2127,8 @@ static int axienet_probe(struct platform_device *pdev)
 	of_node_put(lp->phy_node);
 
 cleanup_clk:
-	clk_disable_unprepare(lp->clk);
+	clk_bulk_disable_unprepare(XAE_NUM_MISC_CLOCKS, lp->misc_clks);
+	clk_disable_unprepare(lp->axi_clk);
 
 free_netdev:
 	free_netdev(ndev);
@@ -2132,7 +2151,8 @@ static int axienet_remove(struct platform_device *pdev)
 
 	axienet_mdio_teardown(lp);
 
-	clk_disable_unprepare(lp->clk);
+	clk_bulk_disable_unprepare(XAE_NUM_MISC_CLOCKS, lp->misc_clks);
+	clk_disable_unprepare(lp->axi_clk);
 
 	of_node_put(lp->phy_node);
 	lp->phy_node = NULL;
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c b/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c
index 9c014cee34b2..48f544f6c999 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c
@@ -159,8 +159,8 @@ int axienet_mdio_enable(struct axienet_local *lp)
 
 	lp->mii_clk_div = 0;
 
-	if (lp->clk) {
-		host_clock = clk_get_rate(lp->clk);
+	if (lp->axi_clk) {
+		host_clock = clk_get_rate(lp->axi_clk);
 	} else {
 		struct device_node *np1;
 
-- 
2.27.0

RE: [PATCH net-next v2 1/2] dt-bindings: net: xilinx_axienet: Document additional clocks

[Radhey Shyam Pandey]

> -----Original Message-----
> From: Robert Hancock <robert.hancock@calian.com>
> Sent: Friday, March 12, 2021 11:13 PM
> To: Radhey Shyam Pandey <radheys@xilinx.com>; davem@davemloft.net;
> kuba@kernel.org
> Cc: netdev@vger.kernel.org; devicetree@vger.kernel.org; Robert Hancock
> <robert.hancock@calian.com>
> Subject: [PATCH net-next v2 1/2] dt-bindings: net: xilinx_axienet: Document
> additional clocks
> 
> Update DT bindings to describe all of the clocks that the axienet driver will
> now be able to make use of.
> 
> Signed-off-by: Robert Hancock <robert.hancock@calian.com>
> ---
>  .../bindings/net/xilinx_axienet.txt           | 25 ++++++++++++++-----
>  1 file changed, 19 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/xilinx_axienet.txt
> b/Documentation/devicetree/bindings/net/xilinx_axienet.txt
> index 2cd452419ed0..5df5ba449b8f 100644
> --- a/Documentation/devicetree/bindings/net/xilinx_axienet.txt
> +++ b/Documentation/devicetree/bindings/net/xilinx_axienet.txt
> @@ -42,11 +42,23 @@ Optional properties:
>  		  support both 1000BaseX and SGMII modes. If set, the phy-
> mode
>  		  should be set to match the mode selected on core reset
> (i.e.
>  		  by the basex_or_sgmii core input line).
> -- clocks	: AXI bus clock for the device. Refer to common clock
> bindings.
> -		  Used to calculate MDIO clock divisor. If not specified, it is
> -		  auto-detected from the CPU clock (but only on platforms
> where
> -		  this is possible). New device trees should specify this - the
> -		  auto detection is only for backward compatibility.
> +- clock-names: 	  Tuple listing input clock names. Possible clocks:
> +		  s_axi_lite_clk: Clock for AXI register slave interface
> +		  axis_clk: AXI stream clock for DMA block

Description for axis_clk should be-
axis_clk: AXI4-Stream clock for TXD RXD TXC and RXS interfaces.
In this patch I assume we are only adding additional clocks for 
1G ethernet subsystem. For dma clocking support we need to add 
more clocks and better to add them in a separate patch. Please refer to
xilinx tree.
> +		  ref_clk: Ethernet reference clock, used by signal delay
> +			   primitives and transceivers
> +		  mgt_clk: MGT reference clock (used by optional internal
> +			   PCS/PMA PHY)
> +
> +		  Note that if s_axi_lite_clk is not specified by name, the
> +		  first clock of any name is used for this. If that is also not
> +		  specified, the clock rate is auto-detected from the CPU
> clock
> +		  (but only on platforms where this is possible). New device
> +		  trees should specify all applicable clocks by name - the
> +		  fallbacks to an unnamed clock or to CPU clock are only for
> +		  backward compatibility.
> +- clocks: 	  Phandles to input clocks matching clock-names. Refer to
> common
> +		  clock bindings.
>  - axistream-connected: Reference to another node which contains the
> resources
>  		       for the AXI DMA controller used by this device.
>  		       If this is specified, the DMA-related resources from that
> @@ -62,7 +74,8 @@ Example:
>  		device_type = "network";
>  		interrupt-parent = <&microblaze_0_axi_intc>;
>  		interrupts = <2 0 1>;
> -		clocks = <&axi_clk>;
> +		clock-names = "s_axi_lite_clk", "axis_clk", "ref_clk",
> "mgt_clk";
> +		clocks = <&axi_clk>, <&axi_clk>, <&pl_enet_ref_clk>,
> <&mgt_clk>;
>  		phy-mode = "mii";
>  		reg = <0x40c00000 0x40000 0x50c00000 0x40000>;
>  		xlnx,rxcsum = <0x2>;
> --
> 2.27.0

Re: [PATCH net-next v2 1/2] dt-bindings: net: xilinx_axienet: Document additional clocks

[Robert Hancock]

On Fri, 2021-03-12 at 18:39 +0000, Radhey Shyam Pandey wrote:
> > -----Original Message-----
> > From: Robert Hancock <robert.hancock@calian.com>
> > Sent: Friday, March 12, 2021 11:13 PM
> > To: Radhey Shyam Pandey <radheys@xilinx.com>; davem@davemloft.net;
> > kuba@kernel.org
> > Cc: netdev@vger.kernel.org; devicetree@vger.kernel.org; Robert Hancock
> > <robert.hancock@calian.com>
> > Subject: [PATCH net-next v2 1/2] dt-bindings: net: xilinx_axienet: Document
> > additional clocks
> > 
> > Update DT bindings to describe all of the clocks that the axienet driver
> > will
> > now be able to make use of.
> > 
> > Signed-off-by: Robert Hancock <robert.hancock@calian.com>
> > ---
> >  .../bindings/net/xilinx_axienet.txt           | 25 ++++++++++++++-----
> >  1 file changed, 19 insertions(+), 6 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/net/xilinx_axienet.txt
> > b/Documentation/devicetree/bindings/net/xilinx_axienet.txt
> > index 2cd452419ed0..5df5ba449b8f 100644
> > --- a/Documentation/devicetree/bindings/net/xilinx_axienet.txt
> > +++ b/Documentation/devicetree/bindings/net/xilinx_axienet.txt
> > @@ -42,11 +42,23 @@ Optional properties:
> >  		  support both 1000BaseX and SGMII modes. If set, the phy-
> > mode
> >  		  should be set to match the mode selected on core reset
> > (i.e.
> >  		  by the basex_or_sgmii core input line).
> > -- clocks	: AXI bus clock for the device. Refer to common clock
> > bindings.
> > -		  Used to calculate MDIO clock divisor. If not specified, it is
> > -		  auto-detected from the CPU clock (but only on platforms
> > where
> > -		  this is possible). New device trees should specify this - the
> > -		  auto detection is only for backward compatibility.
> > +- clock-names: 	  Tuple listing input clock names. Possible clocks:
> > +		  s_axi_lite_clk: Clock for AXI register slave interface
> > +		  axis_clk: AXI stream clock for DMA block
> 
> Description for axis_clk should be-
> axis_clk: AXI4-Stream clock for TXD RXD TXC and RXS interfaces.

Missed this, will add in.

> In this patch I assume we are only adding additional clocks for 
> 1G ethernet subsystem. For dma clocking support we need to add 
> more clocks and better to add them in a separate patch. Please refer to
> xilinx tree.

Correct, here I am just focusing on clocks which are connected to the Ethernet
core itself. It seems the DMA core clocks would be more difficult since those
clocks are attached to the DMA node in the device tree (based on the Vitis-
generated PL device tree content) and not to the node belonging to the Ethernet
platform device. Looking at the Xilinx version of this driver, it seems to
implement retrieving these clocks, but it is using devm_clk_get on the same
platform device used for the Ethernet core, so I am confused how that is
working (or maybe it isn't?)

The DMA core clocks are less of a concern for us, since (at least in our
design) they are driven by the same clock source as one of the Ethernet core
clocks, so they should always be enabled when the Ethernet core clocks are
enabled.

> > +		  ref_clk: Ethernet reference clock, used by signal delay
> > +			   primitives and transceivers
> > +		  mgt_clk: MGT reference clock (used by optional internal
> > +			   PCS/PMA PHY)
> > +
> > +		  Note that if s_axi_lite_clk is not specified by name, the
> > +		  first clock of any name is used for this. If that is also not
> > +		  specified, the clock rate is auto-detected from the CPU
> > clock
> > +		  (but only on platforms where this is possible). New device
> > +		  trees should specify all applicable clocks by name - the
> > +		  fallbacks to an unnamed clock or to CPU clock are only for
> > +		  backward compatibility.
> > +- clocks: 	  Phandles to input clocks matching clock-names. Refer to
> > common
> > +		  clock bindings.
> >  - axistream-connected: Reference to another node which contains the
> > resources
> >  		       for the AXI DMA controller used by this device.
> >  		       If this is specified, the DMA-related resources from
> > that
> > @@ -62,7 +74,8 @@ Example:
> >  		device_type = "network";
> >  		interrupt-parent = <&microblaze_0_axi_intc>;
> >  		interrupts = <2 0 1>;
> > -		clocks = <&axi_clk>;
> > +		clock-names = "s_axi_lite_clk", "axis_clk", "ref_clk",
> > "mgt_clk";
> > +		clocks = <&axi_clk>, <&axi_clk>, <&pl_enet_ref_clk>,
> > <&mgt_clk>;
> >  		phy-mode = "mii";
> >  		reg = <0x40c00000 0x40000 0x50c00000 0x40000>;
> >  		xlnx,rxcsum = <0x2>;
> > --
> > 2.27.0