[PATCH v5 0/4] stmmac: Fixed Phy & PTP fixes

[PATCH v5 0/4] stmmac: Fixed Phy & PTP fixes

[Phil Reid]

Provide ability to specify a fixed phy in the device tree and
retain the mdio bus if no phy is found. This is needed where 
a dsa is connected via a fixed phy and uses the mdio bus for config.
Fixed ptp ref clock calculatins for the stmmac when ptp ref clock
is running at <= 50Mhz. Also add device tree setting to config
ptp clk source on socfpga platforms.

Change from V4:
- Restore #ifdef CONFIG_OF around setting of reset_gpio.
  Member doesn't exist when this isn't defined.

Changes from V3:
- Use if (IS_ENABLED(CONFIG_OF)) instead of #if.
  Reorder some code to reduce if statements.
- of_mdiobus_register already falls back to mdiobus_register
- Tested on system with CONFIG_OF

Changes from V2:
- Formatting, spaces & lines > 80 chars. Using checkpatch
- Drop PTP register debugfs patch.

Changes from V1:
- Fixed mismatch doc / code for ptp_ref_clk dt node. 
- Remove unit address from doc example.

Phil Reid (5):
  stmmac: create of compatible mdio bus for stmacc driver
  stmmac: Correct documentation on stmmac clocks.
  stmmac: Fix calculations for ptp counters when clock input = 50Mhz.
  stmmac: socfpga: Provide dt node to config ptp clk source.

 .../devicetree/bindings/net/socfpga-dwmac.txt      |  2 ++
 Documentation/devicetree/bindings/net/stmmac.txt   | 25 ++++++++++-------
 drivers/net/ethernet/stmicro/stmmac/common.h       |  2 +-
 .../net/ethernet/stmicro/stmmac/dwmac-socfpga.c    |  9 +++++++
 .../net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c  |  9 ++++---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  | 19 ++++++-------
 drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  | 31 +++++++++++++++-------
 .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |  2 +-
 8 files changed, 65 insertions(+), 34 deletions(-)

-- 
1.8.3.1

[PATCH v5 1/4] stmmac: create of compatible mdio bus for stmacc driver

[Phil Reid]

The DSA driver needs to be passed a reference to an mdio bus. Typically
the mac is configured to use a fixed link but the mdio bus still needs
to be registered so that it con configure the switch.
This patch follows the same process as the altera tse ethernet driver for
creation of the mdio bus.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Phil Reid <preid@electromag.com.au>
---
 Documentation/devicetree/bindings/net/stmmac.txt   |  8 ++++++
 drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  | 31 +++++++++++++++-------
 .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |  2 +-
 3 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
index f34fc3c..fd5ddf8 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -47,6 +47,7 @@ Optional properties:
 - snps,burst_len: The AXI burst lenth value of the AXI BUS MODE register.
 - tx-fifo-depth: See ethernet.txt file in the same directory
 - rx-fifo-depth: See ethernet.txt file in the same directory
+- mdio: with compatible = "snps,dwmac-mdio", create and register mdio bus.
 
 Examples:
 
@@ -65,4 +66,11 @@ Examples:
 		tx-fifo-depth = <16384>;
 		clocks = <&clock>;
 		clock-names = "stmmaceth";
+		mdio0 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			compatible = "snps,dwmac-mdio";
+			phy1: ethernet-phy@0 {
+			};
+		};
 	};
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index bba670c..bb6f75c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -29,7 +29,7 @@
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
-
+#include <linux/of_mdio.h>
 #include <asm/io.h>
 
 #include "stmmac.h"
@@ -200,10 +200,29 @@ int stmmac_mdio_register(struct net_device *ndev)
 	struct stmmac_priv *priv = netdev_priv(ndev);
 	struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
 	int addr, found;
+	struct device_node *mdio_node = NULL;
+	struct device_node *child_node = NULL;
 
 	if (!mdio_bus_data)
 		return 0;
 
+	if (IS_ENABLED(CONFIG_OF)) {
+		for_each_child_of_node(priv->device->of_node, child_node) {
+			if (of_device_is_compatible(child_node,
+						    "snps,dwmac-mdio")) {
+				mdio_node = child_node;
+				break;
+			}
+		}
+
+		if (mdio_node) {
+			netdev_dbg(ndev, "FOUND MDIO subnode\n");
+		} else {
+			netdev_err(ndev, "NO MDIO subnode\n");
+			return 0;
+		}
+	}
+
 	new_bus = mdiobus_alloc();
 	if (new_bus == NULL)
 		return -ENOMEM;
@@ -231,7 +250,8 @@ int stmmac_mdio_register(struct net_device *ndev)
 	new_bus->irq = irqlist;
 	new_bus->phy_mask = mdio_bus_data->phy_mask;
 	new_bus->parent = priv->device;
-	err = mdiobus_register(new_bus);
+
+	err = of_mdiobus_register(new_bus, mdio_node);
 	if (err != 0) {
 		pr_err("%s: Cannot register as MDIO bus\n", new_bus->name);
 		goto bus_register_fail;
@@ -284,13 +304,6 @@ int stmmac_mdio_register(struct net_device *ndev)
 		}
 	}
 
-	if (!found) {
-		pr_warn("%s: No PHY found\n", ndev->name);
-		mdiobus_unregister(new_bus);
-		mdiobus_free(new_bus);
-		return -ENODEV;
-	}
-
 	priv->mii = new_bus;
 
 	return 0;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index d02691b..6863420 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -146,7 +146,7 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
 	if (of_property_read_u32(np, "snps,phy-addr", &plat->phy_addr) == 0)
 		dev_warn(&pdev->dev, "snps,phy-addr property is deprecated\n");
 
-	if (plat->phy_node || plat->phy_bus_name)
+	if (plat->phy_bus_name)
 		plat->mdio_bus_data = NULL;
 	else
 		plat->mdio_bus_data =
-- 
1.8.3.1

[PATCH v5 2/4] stmmac: Correct documentation on stmmac clocks.

[Phil Reid]

devm_get_clk looks in clock-name property for matching clock.
the ptp_ref_clk property is ignored.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Phil Reid <preid@electromag.com.au>
---
 Documentation/devicetree/bindings/net/stmmac.txt | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
index fd5ddf8..e862a92 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -35,15 +35,14 @@ Optional properties:
 - reset-names: Should contain the reset signal name "stmmaceth", if a
 	reset phandle is given
 - max-frame-size: See ethernet.txt file in the same directory
-- clocks: If present, the first clock should be the GMAC main clock and
-  the second clock should be peripheral's register interface clock. Further
-  clocks may be specified in derived bindings.
-- clock-names: One name for each entry in the clocks property, the
-  first one should be "stmmaceth" and the second one should be "pclk".
-- clk_ptp_ref: this is the PTP reference clock; in case of the PTP is
-  available this clock is used for programming the Timestamp Addend Register.
-  If not passed then the system clock will be used and this is fine on some
-  platforms.
+- clocks: If present, the first clock should be the GMAC main clock
+  The optional second clock should be peripheral's register interface clock.
+  The third optional clock should be the ptp reference clock.
+  Further clocks may be specified in derived bindings.
+- clock-names: One name for each entry in the clocks property.
+  The first one should be "stmmaceth".
+  The optional second one should be "pclk".
+  The optional third one should be "clk_ptp_ref".
 - snps,burst_len: The AXI burst lenth value of the AXI BUS MODE register.
 - tx-fifo-depth: See ethernet.txt file in the same directory
 - rx-fifo-depth: See ethernet.txt file in the same directory
-- 
1.8.3.1

[PATCH v5 3/4] stmmac: Fix calculations for ptp counters when clock input = 50Mhz.

[Phil Reid]

stmmac_config_sub_second_increment set the sub second increment to 20ns.
Driver is configured to use the fine adjustment method where the sub second
register is incremented when the acculumator incremented by the addend
register wraps overflows. This accumulator is update on every ptp clk
cycle. If a ptp clk with a period of greater than 20ns was used the
sub second register would not get updated correctly.

Instead set the sub sec increment to twice the period of the ptp clk.
This result in the addend register being set mid range and overflow
the accumlator every 2 clock cycles.

Signed-off-by: Phil Reid <preid@electromag.com.au>
---
 drivers/net/ethernet/stmicro/stmmac/common.h          |  2 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c |  9 ++++++---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 19 ++++++++-----------
 3 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index f4518bc..1e19c8f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -439,7 +439,7 @@ struct stmmac_ops {
 /* PTP and HW Timer helpers */
 struct stmmac_hwtimestamp {
 	void (*config_hw_tstamping) (void __iomem *ioaddr, u32 data);
-	void (*config_sub_second_increment) (void __iomem *ioaddr);
+	u32 (*config_sub_second_increment) (void __iomem *ioaddr, u32 clk_rate);
 	int (*init_systime) (void __iomem *ioaddr, u32 sec, u32 nsec);
 	int (*config_addend) (void __iomem *ioaddr, u32 addend);
 	int (*adjust_systime) (void __iomem *ioaddr, u32 sec, u32 nsec,
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
index 76ad214..a77f689 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
@@ -33,22 +33,25 @@ static void stmmac_config_hw_tstamping(void __iomem *ioaddr, u32 data)
 	writel(data, ioaddr + PTP_TCR);
 }
 
-static void stmmac_config_sub_second_increment(void __iomem *ioaddr)
+static u32 stmmac_config_sub_second_increment(void __iomem *ioaddr,
+					      u32 ptp_clock)
 {
 	u32 value = readl(ioaddr + PTP_TCR);
 	unsigned long data;
 
 	/* Convert the ptp_clock to nano second
-	 * formula = (1/ptp_clock) * 1000000000
+	 * formula = (2/ptp_clock) * 1000000000
 	 * where, ptp_clock = 50MHz.
 	 */
-	data = (1000000000ULL / 50000000);
+	data = (2000000000ULL / ptp_clock);
 
 	/* 0.465ns accuracy */
 	if (!(value & PTP_TCR_TSCTRLSSR))
 		data = (data * 1000) / 465;
 
 	writel(data, ioaddr + PTP_SSIR);
+
+	return data;
 }
 
 static int stmmac_init_systime(void __iomem *ioaddr, u32 sec, u32 nsec)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 3c6549a..2231a01 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -53,6 +53,7 @@
 #include "stmmac.h"
 #include <linux/reset.h>
 #include <linux/of_mdio.h>
+#include "dwmac1000.h"
 
 #define STMMAC_ALIGN(x)	L1_CACHE_ALIGN(x)
 
@@ -185,7 +186,7 @@ static void stmmac_clk_csr_set(struct stmmac_priv *priv)
 			priv->clk_csr = STMMAC_CSR_100_150M;
 		else if ((clk_rate >= CSR_F_150M) && (clk_rate < CSR_F_250M))
 			priv->clk_csr = STMMAC_CSR_150_250M;
-		else if ((clk_rate >= CSR_F_250M) && (clk_rate <= CSR_F_300M))
+		else if ((clk_rate >= CSR_F_250M) && (clk_rate < CSR_F_300M))
 			priv->clk_csr = STMMAC_CSR_250_300M;
 	}
 }
@@ -435,6 +436,7 @@ static int stmmac_hwtstamp_ioctl(struct net_device *dev, struct ifreq *ifr)
 	u32 ts_master_en = 0;
 	u32 ts_event_en = 0;
 	u32 value = 0;
+	u32 sec_inc;
 
 	if (!(priv->dma_cap.time_stamp || priv->adv_ts)) {
 		netdev_alert(priv->dev, "No support for HW time stamping\n");
@@ -598,24 +600,19 @@ static int stmmac_hwtstamp_ioctl(struct net_device *dev, struct ifreq *ifr)
 			 tstamp_all | ptp_v2 | ptp_over_ethernet |
 			 ptp_over_ipv6_udp | ptp_over_ipv4_udp | ts_event_en |
 			 ts_master_en | snap_type_sel);
-
 		priv->hw->ptp->config_hw_tstamping(priv->ioaddr, value);
 
 		/* program Sub Second Increment reg */
-		priv->hw->ptp->config_sub_second_increment(priv->ioaddr);
+		sec_inc = priv->hw->ptp->config_sub_second_increment(
+			priv->ioaddr, priv->clk_ptp_rate);
+		temp = div_u64(1000000000ULL, sec_inc);
 
 		/* calculate default added value:
 		 * formula is :
 		 * addend = (2^32)/freq_div_ratio;
-		 * where, freq_div_ratio = clk_ptp_ref_i/50MHz
-		 * hence, addend = ((2^32) * 50MHz)/clk_ptp_ref_i;
-		 * NOTE: clk_ptp_ref_i should be >= 50MHz to
-		 *       achieve 20ns accuracy.
-		 *
-		 * 2^x * y == (y << x), hence
-		 * 2^32 * 50000000 ==> (50000000 << 32)
+		 * where, freq_div_ratio = 1e9ns/sec_inc
 		 */
-		temp = (u64) (50000000ULL << 32);
+		temp = (u64)(temp << 32);
 		priv->default_addend = div_u64(temp, priv->clk_ptp_rate);
 		priv->hw->ptp->config_addend(priv->ioaddr,
 					     priv->default_addend);
-- 
1.8.3.1

[PATCH v5 4/4] stmmac: socfpga: Provide dt node to config ptp clk source.

[Phil Reid]

Provides an options to use the ptp clock routed from the Altera FPGA
fabric. Instead of the defalt eosc1 clock connected to the ARM HPS core.
This setting affects all emacs in the core as the ptp clock is common.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Phil Reid <preid@electromag.com.au>
---
 Documentation/devicetree/bindings/net/socfpga-dwmac.txt | 2 ++
 drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c     | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/socfpga-dwmac.txt b/Documentation/devicetree/bindings/net/socfpga-dwmac.txt
index 3a9d679..72d82d6 100644
--- a/Documentation/devicetree/bindings/net/socfpga-dwmac.txt
+++ b/Documentation/devicetree/bindings/net/socfpga-dwmac.txt
@@ -11,6 +11,8 @@ Required properties:
 		  designware version numbers documented in stmmac.txt
  - altr,sysmgr-syscon : Should be the phandle to the system manager node that
    encompasses the glue register, the register offset, and the register shift.
+ - altr,f2h_ptp_ref_clk use f2h_ptp_ref_clk instead of default eosc1 clock
+   for ptp ref clk. This affects all emacs as the clock is common.
 
 Optional properties:
 altr,emac-splitter: Should be the phandle to the emac splitter soft IP node if
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
index 401383b..f0d797a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
@@ -32,6 +32,7 @@
 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_RMII 0x2
 #define SYSMGR_EMACGRP_CTRL_PHYSEL_WIDTH 2
 #define SYSMGR_EMACGRP_CTRL_PHYSEL_MASK 0x00000003
+#define SYSMGR_EMACGRP_CTRL_PTP_REF_CLK_MASK 0x00000010
 
 #define EMAC_SPLITTER_CTRL_REG			0x0
 #define EMAC_SPLITTER_CTRL_SPEED_MASK		0x3
@@ -47,6 +48,7 @@ struct socfpga_dwmac {
 	struct regmap *sys_mgr_base_addr;
 	struct reset_control *stmmac_rst;
 	void __iomem *splitter_base;
+	bool f2h_ptp_ref_clk;
 };
 
 static void socfpga_dwmac_fix_mac_speed(void *priv, unsigned int speed)
@@ -116,6 +118,8 @@ static int socfpga_dwmac_parse_data(struct socfpga_dwmac *dwmac, struct device *
 		return -EINVAL;
 	}
 
+	dwmac->f2h_ptp_ref_clk = of_property_read_bool(np, "altr,f2h_ptp_ref_clk");
+
 	np_splitter = of_parse_phandle(np, "altr,emac-splitter", 0);
 	if (np_splitter) {
 		if (of_address_to_resource(np_splitter, 0, &res_splitter)) {
@@ -171,6 +175,11 @@ static int socfpga_dwmac_setup(struct socfpga_dwmac *dwmac)
 	ctrl &= ~(SYSMGR_EMACGRP_CTRL_PHYSEL_MASK << reg_shift);
 	ctrl |= val << reg_shift;
 
+	if (dwmac->f2h_ptp_ref_clk)
+		ctrl |= SYSMGR_EMACGRP_CTRL_PTP_REF_CLK_MASK << (reg_shift / 2);
+	else
+		ctrl &= ~(SYSMGR_EMACGRP_CTRL_PTP_REF_CLK_MASK << (reg_shift / 2));
+
 	regmap_write(sys_mgr_base_addr, reg_offset, ctrl);
 	return 0;
 }
-- 
1.8.3.1

Re: [PATCH v5 0/4] stmmac: Fixed Phy & PTP fixes

[David Miller]

Please fix the date and time on your computer.

Re: [PATCH v5 1/4] stmmac: create of compatible mdio bus for stmacc driver

[Giuseppe CAVALLARO]

Hi

also pls fix this typo

stmmac: create of compatible mdio bus for stmacc driver
                                          ^^^^^^^^
                                           stmmac

On 12/9/2015 9:39 AM, Phil Reid wrote:
> The DSA driver needs to be passed a reference to an mdio bus. Typically
> the mac is configured to use a fixed link but the mdio bus still needs
> to be registered so that it con configure the switch.
> This patch follows the same process as the altera tse ethernet driver for
> creation of the mdio bus.
>
> Acked-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Phil Reid <preid@electromag.com.au>
> ---
>   Documentation/devicetree/bindings/net/stmmac.txt   |  8 ++++++
>   drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  | 31 +++++++++++++++-------
>   .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |  2 +-
>   3 files changed, 31 insertions(+), 10 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
> index f34fc3c..fd5ddf8 100644
> --- a/Documentation/devicetree/bindings/net/stmmac.txt
> +++ b/Documentation/devicetree/bindings/net/stmmac.txt
> @@ -47,6 +47,7 @@ Optional properties:
>   - snps,burst_len: The AXI burst lenth value of the AXI BUS MODE register.
>   - tx-fifo-depth: See ethernet.txt file in the same directory
>   - rx-fifo-depth: See ethernet.txt file in the same directory
> +- mdio: with compatible = "snps,dwmac-mdio", create and register mdio bus.
>
>   Examples:
>
> @@ -65,4 +66,11 @@ Examples:
>   		tx-fifo-depth = <16384>;
>   		clocks = <&clock>;
>   		clock-names = "stmmaceth";
> +		mdio0 {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			compatible = "snps,dwmac-mdio";
> +			phy1: ethernet-phy@0 {
> +			};
> +		};
>   	};
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> index bba670c..bb6f75c 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> @@ -29,7 +29,7 @@
>   #include <linux/slab.h>
>   #include <linux/of.h>
>   #include <linux/of_gpio.h>
> -
> +#include <linux/of_mdio.h>
>   #include <asm/io.h>
>
>   #include "stmmac.h"
> @@ -200,10 +200,29 @@ int stmmac_mdio_register(struct net_device *ndev)
>   	struct stmmac_priv *priv = netdev_priv(ndev);
>   	struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
>   	int addr, found;
> +	struct device_node *mdio_node = NULL;
> +	struct device_node *child_node = NULL;
>
>   	if (!mdio_bus_data)
>   		return 0;
>
> +	if (IS_ENABLED(CONFIG_OF)) {
> +		for_each_child_of_node(priv->device->of_node, child_node) {
> +			if (of_device_is_compatible(child_node,
> +						    "snps,dwmac-mdio")) {
> +				mdio_node = child_node;
> +				break;
> +			}
> +		}
> +
> +		if (mdio_node) {
> +			netdev_dbg(ndev, "FOUND MDIO subnode\n");
> +		} else {
> +			netdev_err(ndev, "NO MDIO subnode\n");
> +			return 0;
> +		}
> +	}
> +
>   	new_bus = mdiobus_alloc();
>   	if (new_bus == NULL)
>   		return -ENOMEM;
> @@ -231,7 +250,8 @@ int stmmac_mdio_register(struct net_device *ndev)
>   	new_bus->irq = irqlist;
>   	new_bus->phy_mask = mdio_bus_data->phy_mask;
>   	new_bus->parent = priv->device;
> -	err = mdiobus_register(new_bus);
> +
> +	err = of_mdiobus_register(new_bus, mdio_node);
>   	if (err != 0) {
>   		pr_err("%s: Cannot register as MDIO bus\n", new_bus->name);
>   		goto bus_register_fail;
> @@ -284,13 +304,6 @@ int stmmac_mdio_register(struct net_device *ndev)
>   		}
>   	}
>
> -	if (!found) {
> -		pr_warn("%s: No PHY found\n", ndev->name);
> -		mdiobus_unregister(new_bus);
> -		mdiobus_free(new_bus);
> -		return -ENODEV;
> -	}

hmm,  this could be necessary on some platforms that wants to
get the phy addr at runtime and in case of failure then
removes the registered bus.

> -
>   	priv->mii = new_bus;
>
>   	return 0;
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index d02691b..6863420 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -146,7 +146,7 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
>   	if (of_property_read_u32(np, "snps,phy-addr", &plat->phy_addr) == 0)
>   		dev_warn(&pdev->dev, "snps,phy-addr property is deprecated\n");
>
> -	if (plat->phy_node || plat->phy_bus_name)

can this breaks some conf case?

> +	if (plat->phy_bus_name)
>   		plat->mdio_bus_data = NULL;
>   	else
>   		plat->mdio_bus_data =
>

peppe

Re: [PATCH v5 1/4] stmmac: create of compatible mdio bus for stmacc driver

[Giuseppe CAVALLARO]

Hi

also pls fix this typo

stmmac: create of compatible mdio bus for stmacc driver
                                          ^^^^^^^^
                                           stmmac

On 12/9/2015 9:39 AM, Phil Reid wrote:
> The DSA driver needs to be passed a reference to an mdio bus. Typically
> the mac is configured to use a fixed link but the mdio bus still needs
> to be registered so that it con configure the switch.
> This patch follows the same process as the altera tse ethernet driver for
> creation of the mdio bus.
>
> Acked-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Phil Reid <preid@electromag.com.au>
> ---
>   Documentation/devicetree/bindings/net/stmmac.txt   |  8 ++++++
>   drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  | 31 +++++++++++++++-------
>   .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |  2 +-
>   3 files changed, 31 insertions(+), 10 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
> index f34fc3c..fd5ddf8 100644
> --- a/Documentation/devicetree/bindings/net/stmmac.txt
> +++ b/Documentation/devicetree/bindings/net/stmmac.txt
> @@ -47,6 +47,7 @@ Optional properties:
>   - snps,burst_len: The AXI burst lenth value of the AXI BUS MODE register.
>   - tx-fifo-depth: See ethernet.txt file in the same directory
>   - rx-fifo-depth: See ethernet.txt file in the same directory
> +- mdio: with compatible = "snps,dwmac-mdio", create and register mdio bus.
>
>   Examples:
>
> @@ -65,4 +66,11 @@ Examples:
>   		tx-fifo-depth = <16384>;
>   		clocks = <&clock>;
>   		clock-names = "stmmaceth";
> +		mdio0 {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			compatible = "snps,dwmac-mdio";
> +			phy1: ethernet-phy@0 {
> +			};
> +		};
>   	};
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> index bba670c..bb6f75c 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> @@ -29,7 +29,7 @@
>   #include <linux/slab.h>
>   #include <linux/of.h>
>   #include <linux/of_gpio.h>
> -
> +#include <linux/of_mdio.h>
>   #include <asm/io.h>
>
>   #include "stmmac.h"
> @@ -200,10 +200,29 @@ int stmmac_mdio_register(struct net_device *ndev)
>   	struct stmmac_priv *priv = netdev_priv(ndev);
>   	struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
>   	int addr, found;
> +	struct device_node *mdio_node = NULL;
> +	struct device_node *child_node = NULL;
>
>   	if (!mdio_bus_data)
>   		return 0;
>
> +	if (IS_ENABLED(CONFIG_OF)) {
> +		for_each_child_of_node(priv->device->of_node, child_node) {
> +			if (of_device_is_compatible(child_node,
> +						    "snps,dwmac-mdio")) {
> +				mdio_node = child_node;
> +				break;
> +			}
> +		}
> +
> +		if (mdio_node) {
> +			netdev_dbg(ndev, "FOUND MDIO subnode\n");
> +		} else {
> +			netdev_err(ndev, "NO MDIO subnode\n");
> +			return 0;
> +		}
> +	}
> +
>   	new_bus = mdiobus_alloc();
>   	if (new_bus == NULL)
>   		return -ENOMEM;
> @@ -231,7 +250,8 @@ int stmmac_mdio_register(struct net_device *ndev)
>   	new_bus->irq = irqlist;
>   	new_bus->phy_mask = mdio_bus_data->phy_mask;
>   	new_bus->parent = priv->device;
> -	err = mdiobus_register(new_bus);
> +
> +	err = of_mdiobus_register(new_bus, mdio_node);
>   	if (err != 0) {
>   		pr_err("%s: Cannot register as MDIO bus\n", new_bus->name);
>   		goto bus_register_fail;
> @@ -284,13 +304,6 @@ int stmmac_mdio_register(struct net_device *ndev)
>   		}
>   	}
>
> -	if (!found) {
> -		pr_warn("%s: No PHY found\n", ndev->name);
> -		mdiobus_unregister(new_bus);
> -		mdiobus_free(new_bus);
> -		return -ENODEV;
> -	}

hmm,  this could be necessary on some platforms that wants to
get the phy addr at runtime and in case of failure then
removes the registered bus.

> -
>   	priv->mii = new_bus;
>
>   	return 0;
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index d02691b..6863420 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -146,7 +146,7 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
>   	if (of_property_read_u32(np, "snps,phy-addr", &plat->phy_addr) == 0)
>   		dev_warn(&pdev->dev, "snps,phy-addr property is deprecated\n");
>
> -	if (plat->phy_node || plat->phy_bus_name)

can this breaks some conf case?

> +	if (plat->phy_bus_name)
>   		plat->mdio_bus_data = NULL;
>   	else
>   		plat->mdio_bus_data =
>

peppe

Re: [PATCH v5 1/4] stmmac: create of compatible mdio bus for stmacc driver

[Phil Reid]

G'day Giuseppe,

On 11/12/2015 1:16 AM, Giuseppe CAVALLARO wrote:
> Hi
>
> also pls fix this typo
>
> stmmac: create of compatible mdio bus for stmacc driver
>                                           ^^^^^^^^
>                                            stmmac
Will do.
>
> On 12/9/2015 9:39 AM, Phil Reid wrote:
>> The DSA driver needs to be passed a reference to an mdio bus. Typically
>> the mac is configured to use a fixed link but the mdio bus still needs
>> to be registered so that it con configure the switch.
>> This patch follows the same process as the altera tse ethernet driver for
>> creation of the mdio bus.
>>
>> Acked-by: Rob Herring <robh@kernel.org>
>> Signed-off-by: Phil Reid <preid@electromag.com.au>
>> ---
>>   Documentation/devicetree/bindings/net/stmmac.txt   |  8 ++++++
>>   drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  | 31 +++++++++++++++-------
>>   .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |  2 +-
>>   3 files changed, 31 insertions(+), 10 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
>> index f34fc3c..fd5ddf8 100644
>> --- a/Documentation/devicetree/bindings/net/stmmac.txt
>> +++ b/Documentation/devicetree/bindings/net/stmmac.txt
>> @@ -47,6 +47,7 @@ Optional properties:
>>   - snps,burst_len: The AXI burst lenth value of the AXI BUS MODE register.
>>   - tx-fifo-depth: See ethernet.txt file in the same directory
>>   - rx-fifo-depth: See ethernet.txt file in the same directory
>> +- mdio: with compatible = "snps,dwmac-mdio", create and register mdio bus.
>>
>>   Examples:
>>
>> @@ -65,4 +66,11 @@ Examples:
>>           tx-fifo-depth = <16384>;
>>           clocks = <&clock>;
>>           clock-names = "stmmaceth";
>> +        mdio0 {
>> +            #address-cells = <1>;
>> +            #size-cells = <0>;
>> +            compatible = "snps,dwmac-mdio";
>> +            phy1: ethernet-phy@0 {
>> +            };
>> +        };
>>       };
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>> index bba670c..bb6f75c 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>> @@ -29,7 +29,7 @@
>>   #include <linux/slab.h>
>>   #include <linux/of.h>
>>   #include <linux/of_gpio.h>
>> -
>> +#include <linux/of_mdio.h>
>>   #include <asm/io.h>
>>
>>   #include "stmmac.h"
>> @@ -200,10 +200,29 @@ int stmmac_mdio_register(struct net_device *ndev)
>>       struct stmmac_priv *priv = netdev_priv(ndev);
>>       struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
>>       int addr, found;
>> +    struct device_node *mdio_node = NULL;
>> +    struct device_node *child_node = NULL;
>>
>>       if (!mdio_bus_data)
>>           return 0;
>>
>> +    if (IS_ENABLED(CONFIG_OF)) {
>> +        for_each_child_of_node(priv->device->of_node, child_node) {
>> +            if (of_device_is_compatible(child_node,
>> +                            "snps,dwmac-mdio")) {
>> +                mdio_node = child_node;
>> +                break;
>> +            }
>> +        }
>> +
>> +        if (mdio_node) {
>> +            netdev_dbg(ndev, "FOUND MDIO subnode\n");
>> +        } else {
>> +            netdev_err(ndev, "NO MDIO subnode\n");
>> +            return 0;
>> +        }
>> +    }
>> +
>>       new_bus = mdiobus_alloc();
>>       if (new_bus == NULL)
>>           return -ENOMEM;
>> @@ -231,7 +250,8 @@ int stmmac_mdio_register(struct net_device *ndev)
>>       new_bus->irq = irqlist;
>>       new_bus->phy_mask = mdio_bus_data->phy_mask;
>>       new_bus->parent = priv->device;
>> -    err = mdiobus_register(new_bus);
>> +
>> +    err = of_mdiobus_register(new_bus, mdio_node);
>>       if (err != 0) {
>>           pr_err("%s: Cannot register as MDIO bus\n", new_bus->name);
>>           goto bus_register_fail;
>> @@ -284,13 +304,6 @@ int stmmac_mdio_register(struct net_device *ndev)
>>           }
>>       }
>>
>> -    if (!found) {
>> -        pr_warn("%s: No PHY found\n", ndev->name);
>> -        mdiobus_unregister(new_bus);
>> -        mdiobus_free(new_bus);
>> -        return -ENODEV;
>> -    }
>
> hmm,  this could be necessary on some platforms that wants to
> get the phy addr at runtime and in case of failure then
> removes the registered bus.
>
Could make this conditional on (!found && !mdio_node).
Therefore if dt node exists it will be created regardless, otherwise unregister if nothing found.
Thoughts?

>> -
>>       priv->mii = new_bus;
>>
>>       return 0;
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> index d02691b..6863420 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> @@ -146,7 +146,7 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
>>       if (of_property_read_u32(np, "snps,phy-addr", &plat->phy_addr) == 0)
>>           dev_warn(&pdev->dev, "snps,phy-addr property is deprecated\n");
>>ec
>> -    if (plat->phy_node || plat->phy_bus_name)
>
I think that would be dependent on the device tree.
However this may also work:
if ((plat->phy_node && !of_phy_is_fixed_link(np)) || plat->phy_bus_name)

> can this breaks some conf case?
>
>> +    if (plat->phy_bus_name)
>>           plat->mdio_bus_data = NULL;
>>       else
>>           plat->mdio_bus_data =
>>

Alternatively the solution would be to introduce some non standard device tree node
to force the creation of the mdio bus.


-- 
Regards
Phil Reid

Re: [PATCH v5 1/4] stmmac: create of compatible mdio bus for stmacc driver

[Giuseppe CAVALLARO]

Hello Phil

On 12/11/2015 2:44 AM, Phil Reid wrote:
> G'day Giuseppe,
>
> On 11/12/2015 1:16 AM, Giuseppe CAVALLARO wrote:
>> Hi
>>
>> also pls fix this typo
>>
>> stmmac: create of compatible mdio bus for stmacc driver
>>                                           ^^^^^^^^
>>                                            stmmac
> Will do.
>>
>> On 12/9/2015 9:39 AM, Phil Reid wrote:
>>> The DSA driver needs to be passed a reference to an mdio bus. Typically
>>> the mac is configured to use a fixed link but the mdio bus still needs
>>> to be registered so that it con configure the switch.
>>> This patch follows the same process as the altera tse ethernet driver
>>> for
>>> creation of the mdio bus.
>>>
>>> Acked-by: Rob Herring <robh@kernel.org>
>>> Signed-off-by: Phil Reid <preid@electromag.com.au>
>>> ---
>>>   Documentation/devicetree/bindings/net/stmmac.txt   |  8 ++++++
>>>   drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  | 31
>>> +++++++++++++++-------
>>>   .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |  2 +-
>>>   3 files changed, 31 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/net/stmmac.txt
>>> b/Documentation/devicetree/bindings/net/stmmac.txt
>>> index f34fc3c..fd5ddf8 100644
>>> --- a/Documentation/devicetree/bindings/net/stmmac.txt
>>> +++ b/Documentation/devicetree/bindings/net/stmmac.txt
>>> @@ -47,6 +47,7 @@ Optional properties:
>>>   - snps,burst_len: The AXI burst lenth value of the AXI BUS MODE
>>> register.
>>>   - tx-fifo-depth: See ethernet.txt file in the same directory
>>>   - rx-fifo-depth: See ethernet.txt file in the same directory
>>> +- mdio: with compatible = "snps,dwmac-mdio", create and register
>>> mdio bus.
>>>
>>>   Examples:
>>>
>>> @@ -65,4 +66,11 @@ Examples:
>>>           tx-fifo-depth = <16384>;
>>>           clocks = <&clock>;
>>>           clock-names = "stmmaceth";
>>> +        mdio0 {
>>> +            #address-cells = <1>;
>>> +            #size-cells = <0>;
>>> +            compatible = "snps,dwmac-mdio";
>>> +            phy1: ethernet-phy@0 {
>>> +            };
>>> +        };
>>>       };
>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>>> b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>>> index bba670c..bb6f75c 100644
>>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>>> @@ -29,7 +29,7 @@
>>>   #include <linux/slab.h>
>>>   #include <linux/of.h>
>>>   #include <linux/of_gpio.h>
>>> -
>>> +#include <linux/of_mdio.h>
>>>   #include <asm/io.h>
>>>
>>>   #include "stmmac.h"
>>> @@ -200,10 +200,29 @@ int stmmac_mdio_register(struct net_device *ndev)
>>>       struct stmmac_priv *priv = netdev_priv(ndev);
>>>       struct stmmac_mdio_bus_data *mdio_bus_data =
>>> priv->plat->mdio_bus_data;
>>>       int addr, found;
>>> +    struct device_node *mdio_node = NULL;
>>> +    struct device_node *child_node = NULL;
>>>
>>>       if (!mdio_bus_data)
>>>           return 0;
>>>
>>> +    if (IS_ENABLED(CONFIG_OF)) {
>>> +        for_each_child_of_node(priv->device->of_node, child_node) {
>>> +            if (of_device_is_compatible(child_node,
>>> +                            "snps,dwmac-mdio")) {
>>> +                mdio_node = child_node;
>>> +                break;
>>> +            }
>>> +        }
>>> +
>>> +        if (mdio_node) {
>>> +            netdev_dbg(ndev, "FOUND MDIO subnode\n");
>>> +        } else {
>>> +            netdev_err(ndev, "NO MDIO subnode\n");
>>> +            return 0;
>>> +        }
>>> +    }
>>> +
>>>       new_bus = mdiobus_alloc();
>>>       if (new_bus == NULL)
>>>           return -ENOMEM;
>>> @@ -231,7 +250,8 @@ int stmmac_mdio_register(struct net_device *ndev)
>>>       new_bus->irq = irqlist;
>>>       new_bus->phy_mask = mdio_bus_data->phy_mask;
>>>       new_bus->parent = priv->device;
>>> -    err = mdiobus_register(new_bus);
>>> +
>>> +    err = of_mdiobus_register(new_bus, mdio_node);
>>>       if (err != 0) {
>>>           pr_err("%s: Cannot register as MDIO bus\n", new_bus->name);
>>>           goto bus_register_fail;
>>> @@ -284,13 +304,6 @@ int stmmac_mdio_register(struct net_device *ndev)
>>>           }
>>>       }
>>>
>>> -    if (!found) {
>>> -        pr_warn("%s: No PHY found\n", ndev->name);
>>> -        mdiobus_unregister(new_bus);
>>> -        mdiobus_free(new_bus);
>>> -        return -ENODEV;
>>> -    }
>>
>> hmm,  this could be necessary on some platforms that wants to
>> get the phy addr at runtime and in case of failure then
>> removes the registered bus.
>>
> Could make this conditional on (!found && !mdio_node).
> Therefore if dt node exists it will be created regardless, otherwise
> unregister if nothing found.
> Thoughts?
>
>>> -
>>>       priv->mii = new_bus;
>>>
>>>       return 0;
>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> index d02691b..6863420 100644
>>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> @@ -146,7 +146,7 @@ stmmac_probe_config_dt(struct platform_device
>>> *pdev, const char **mac)
>>>       if (of_property_read_u32(np, "snps,phy-addr", &plat->phy_addr)
>>> == 0)
>>>           dev_warn(&pdev->dev, "snps,phy-addr property is
>>> deprecated\n");
>>> ec
>>> -    if (plat->phy_node || plat->phy_bus_name)
>>
> I think that would be dependent on the device tree.
> However this may also work:
> if ((plat->phy_node && !of_phy_is_fixed_link(np)) || plat->phy_bus_name)

that's ok for me

>
>> can this breaks some conf case?
>>
>>> +    if (plat->phy_bus_name)
>>>           plat->mdio_bus_data = NULL;
>>>       else
>>>           plat->mdio_bus_data =
>>>
>
> Alternatively the solution would be to introduce some non standard
> device tree node
> to force the creation of the mdio bus.

no, I guess the easier way is what you proposed.

Peppe

>
>

Re: [PATCH v5 1/4] stmmac: create of compatible mdio bus for stmacc driver

[Giuseppe CAVALLARO]

Hello Phil

On 12/11/2015 2:44 AM, Phil Reid wrote:
> G'day Giuseppe,
>
> On 11/12/2015 1:16 AM, Giuseppe CAVALLARO wrote:
>> Hi
>>
>> also pls fix this typo
>>
>> stmmac: create of compatible mdio bus for stmacc driver
>>                                           ^^^^^^^^
>>                                            stmmac
> Will do.
>>
>> On 12/9/2015 9:39 AM, Phil Reid wrote:
>>> The DSA driver needs to be passed a reference to an mdio bus. Typically
>>> the mac is configured to use a fixed link but the mdio bus still needs
>>> to be registered so that it con configure the switch.
>>> This patch follows the same process as the altera tse ethernet driver
>>> for
>>> creation of the mdio bus.
>>>
>>> Acked-by: Rob Herring <robh@kernel.org>
>>> Signed-off-by: Phil Reid <preid@electromag.com.au>
>>> ---
>>>   Documentation/devicetree/bindings/net/stmmac.txt   |  8 ++++++
>>>   drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c  | 31
>>> +++++++++++++++-------
>>>   .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |  2 +-
>>>   3 files changed, 31 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/net/stmmac.txt
>>> b/Documentation/devicetree/bindings/net/stmmac.txt
>>> index f34fc3c..fd5ddf8 100644
>>> --- a/Documentation/devicetree/bindings/net/stmmac.txt
>>> +++ b/Documentation/devicetree/bindings/net/stmmac.txt
>>> @@ -47,6 +47,7 @@ Optional properties:
>>>   - snps,burst_len: The AXI burst lenth value of the AXI BUS MODE
>>> register.
>>>   - tx-fifo-depth: See ethernet.txt file in the same directory
>>>   - rx-fifo-depth: See ethernet.txt file in the same directory
>>> +- mdio: with compatible = "snps,dwmac-mdio", create and register
>>> mdio bus.
>>>
>>>   Examples:
>>>
>>> @@ -65,4 +66,11 @@ Examples:
>>>           tx-fifo-depth = <16384>;
>>>           clocks = <&clock>;
>>>           clock-names = "stmmaceth";
>>> +        mdio0 {
>>> +            #address-cells = <1>;
>>> +            #size-cells = <0>;
>>> +            compatible = "snps,dwmac-mdio";
>>> +            phy1: ethernet-phy@0 {
>>> +            };
>>> +        };
>>>       };
>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>>> b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>>> index bba670c..bb6f75c 100644
>>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
>>> @@ -29,7 +29,7 @@
>>>   #include <linux/slab.h>
>>>   #include <linux/of.h>
>>>   #include <linux/of_gpio.h>
>>> -
>>> +#include <linux/of_mdio.h>
>>>   #include <asm/io.h>
>>>
>>>   #include "stmmac.h"
>>> @@ -200,10 +200,29 @@ int stmmac_mdio_register(struct net_device *ndev)
>>>       struct stmmac_priv *priv = netdev_priv(ndev);
>>>       struct stmmac_mdio_bus_data *mdio_bus_data =
>>> priv->plat->mdio_bus_data;
>>>       int addr, found;
>>> +    struct device_node *mdio_node = NULL;
>>> +    struct device_node *child_node = NULL;
>>>
>>>       if (!mdio_bus_data)
>>>           return 0;
>>>
>>> +    if (IS_ENABLED(CONFIG_OF)) {
>>> +        for_each_child_of_node(priv->device->of_node, child_node) {
>>> +            if (of_device_is_compatible(child_node,
>>> +                            "snps,dwmac-mdio")) {
>>> +                mdio_node = child_node;
>>> +                break;
>>> +            }
>>> +        }
>>> +
>>> +        if (mdio_node) {
>>> +            netdev_dbg(ndev, "FOUND MDIO subnode\n");
>>> +        } else {
>>> +            netdev_err(ndev, "NO MDIO subnode\n");
>>> +            return 0;
>>> +        }
>>> +    }
>>> +
>>>       new_bus = mdiobus_alloc();
>>>       if (new_bus == NULL)
>>>           return -ENOMEM;
>>> @@ -231,7 +250,8 @@ int stmmac_mdio_register(struct net_device *ndev)
>>>       new_bus->irq = irqlist;
>>>       new_bus->phy_mask = mdio_bus_data->phy_mask;
>>>       new_bus->parent = priv->device;
>>> -    err = mdiobus_register(new_bus);
>>> +
>>> +    err = of_mdiobus_register(new_bus, mdio_node);
>>>       if (err != 0) {
>>>           pr_err("%s: Cannot register as MDIO bus\n", new_bus->name);
>>>           goto bus_register_fail;
>>> @@ -284,13 +304,6 @@ int stmmac_mdio_register(struct net_device *ndev)
>>>           }
>>>       }
>>>
>>> -    if (!found) {
>>> -        pr_warn("%s: No PHY found\n", ndev->name);
>>> -        mdiobus_unregister(new_bus);
>>> -        mdiobus_free(new_bus);
>>> -        return -ENODEV;
>>> -    }
>>
>> hmm,  this could be necessary on some platforms that wants to
>> get the phy addr at runtime and in case of failure then
>> removes the registered bus.
>>
> Could make this conditional on (!found && !mdio_node).
> Therefore if dt node exists it will be created regardless, otherwise
> unregister if nothing found.
> Thoughts?
>
>>> -
>>>       priv->mii = new_bus;
>>>
>>>       return 0;
>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> index d02691b..6863420 100644
>>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> @@ -146,7 +146,7 @@ stmmac_probe_config_dt(struct platform_device
>>> *pdev, const char **mac)
>>>       if (of_property_read_u32(np, "snps,phy-addr", &plat->phy_addr)
>>> == 0)
>>>           dev_warn(&pdev->dev, "snps,phy-addr property is
>>> deprecated\n");
>>> ec
>>> -    if (plat->phy_node || plat->phy_bus_name)
>>
> I think that would be dependent on the device tree.
> However this may also work:
> if ((plat->phy_node && !of_phy_is_fixed_link(np)) || plat->phy_bus_name)

that's ok for me

>
>> can this breaks some conf case?
>>
>>> +    if (plat->phy_bus_name)
>>>           plat->mdio_bus_data = NULL;
>>>       else
>>>           plat->mdio_bus_data =
>>>
>
> Alternatively the solution would be to introduce some non standard
> device tree node
> to force the creation of the mdio bus.

no, I guess the easier way is what you proposed.

Peppe

>
>