[PATCH net-next v5 5/6] net: tn40xx: add mdio bus support

[PATCH net-next v5 5/6] net: tn40xx: add mdio bus support

[FUJITA Tomonori]

This patch adds supports for mdio bus. A later path adds PHYLIB
support on the top of this.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
---
 drivers/net/ethernet/tehuti/Makefile    |   2 +-
 drivers/net/ethernet/tehuti/tn40.c      |   6 ++
 drivers/net/ethernet/tehuti/tn40.h      |   3 +
 drivers/net/ethernet/tehuti/tn40_mdio.c | 134 ++++++++++++++++++++++++
 4 files changed, 144 insertions(+), 1 deletion(-)
 create mode 100644 drivers/net/ethernet/tehuti/tn40_mdio.c

diff --git a/drivers/net/ethernet/tehuti/Makefile b/drivers/net/ethernet/tehuti/Makefile
index 1c468d99e476..7a0fe586a243 100644
--- a/drivers/net/ethernet/tehuti/Makefile
+++ b/drivers/net/ethernet/tehuti/Makefile
@@ -5,5 +5,5 @@
 
 obj-$(CONFIG_TEHUTI) += tehuti.o
 
-tn40xx-y := tn40.o
+tn40xx-y := tn40.o tn40_mdio.o
 obj-$(CONFIG_TEHUTI_TN40) += tn40xx.o
diff --git a/drivers/net/ethernet/tehuti/tn40.c b/drivers/net/ethernet/tehuti/tn40.c
index b923ea58f2d4..07690c1d3f32 100644
--- a/drivers/net/ethernet/tehuti/tn40.c
+++ b/drivers/net/ethernet/tehuti/tn40.c
@@ -1780,6 +1780,12 @@ static int tn40_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto err_unset_drvdata;
 	}
 
+	ret = tn40_mdiobus_init(priv);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to initialize mdio bus.\n");
+		goto err_free_irq;
+	}
+
 	priv->stats_flag =
 		((tn40_read_reg(priv, TN40_FPGA_VER) & 0xFFF) != 308);
 
diff --git a/drivers/net/ethernet/tehuti/tn40.h b/drivers/net/ethernet/tehuti/tn40.h
index 19bf1652b579..c9af2fa8faa1 100644
--- a/drivers/net/ethernet/tehuti/tn40.h
+++ b/drivers/net/ethernet/tehuti/tn40.h
@@ -160,6 +160,7 @@ struct tn40_priv {
 	char *b0_va; /* Virtual address of buffer */
 
 	struct tn40_rx_page_table rx_page_table;
+	struct mii_bus *mdio;
 };
 
 /* RX FREE descriptor - 64bit */
@@ -239,4 +240,6 @@ static inline void tn40_write_reg(struct tn40_priv *priv, u32 reg, u32 val)
 	writel(val, priv->regs + reg);
 }
 
+int tn40_mdiobus_init(struct tn40_priv *priv);
+
 #endif /* _TN40XX_H */
diff --git a/drivers/net/ethernet/tehuti/tn40_mdio.c b/drivers/net/ethernet/tehuti/tn40_mdio.c
new file mode 100644
index 000000000000..64ef7f40f25d
--- /dev/null
+++ b/drivers/net/ethernet/tehuti/tn40_mdio.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (c) Tehuti Networks Ltd. */
+
+#include <linux/netdevice.h>
+#include <linux/pci.h>
+#include <linux/phylink.h>
+
+#include "tn40.h"
+
+static void tn40_mdio_set_speed(struct tn40_priv *priv, u32 speed)
+{
+	void __iomem *regs = priv->regs;
+	int mdio_cfg;
+
+	mdio_cfg = readl(regs + TN40_REG_MDIO_CMD_STAT);
+	if (speed == 1)
+		mdio_cfg = (0x7d << 7) | 0x08;	/* 1MHz */
+	else
+		mdio_cfg = 0xA08;	/* 6MHz */
+	mdio_cfg |= (1 << 6);
+	writel(mdio_cfg, regs + TN40_REG_MDIO_CMD_STAT);
+	msleep(100);
+}
+
+static u32 tn40_mdio_stat(struct tn40_priv *priv)
+{
+	void __iomem *regs = priv->regs;
+
+	return readl(regs + TN40_REG_MDIO_CMD_STAT);
+}
+
+static int tn40_mdio_get(struct tn40_priv *priv, u32 *val)
+{
+	u32 stat;
+
+	return readx_poll_timeout_atomic(tn40_mdio_stat, priv, stat,
+					 TN40_GET_MDIO_BUSY(stat) == 0, 10,
+					 10000);
+}
+
+static int tn40_mdio_read(struct tn40_priv *priv, int port, int device,
+			  u16 regnum)
+{
+	void __iomem *regs = priv->regs;
+	u32 tmp_reg, i;
+
+	/* wait until MDIO is not busy */
+	if (tn40_mdio_get(priv, NULL))
+		return -EIO;
+
+	i = ((device & 0x1F) | ((port & 0x1F) << 5));
+	writel(i, regs + TN40_REG_MDIO_CMD);
+	writel((u32)regnum, regs + TN40_REG_MDIO_ADDR);
+	if (tn40_mdio_get(priv, NULL))
+		return -EIO;
+
+	writel(((1 << 15) | i), regs + TN40_REG_MDIO_CMD);
+	/* read CMD_STAT until not busy */
+	if (tn40_mdio_get(priv, NULL))
+		return -EIO;
+
+	tmp_reg = readl(regs + TN40_REG_MDIO_DATA);
+	return lower_16_bits(tmp_reg);
+}
+
+static int tn40_mdio_write(struct tn40_priv *priv, int port, int device,
+			   u16 regnum, u16 data)
+{
+	void __iomem *regs = priv->regs;
+	u32 tmp_reg = 0;
+	int ret;
+
+	/* wait until MDIO is not busy */
+	if (tn40_mdio_get(priv, NULL))
+		return -EIO;
+	writel(((device & 0x1F) | ((port & 0x1F) << 5)),
+	       regs + TN40_REG_MDIO_CMD);
+	writel((u32)regnum, regs + TN40_REG_MDIO_ADDR);
+	if (tn40_mdio_get(priv, NULL))
+		return -EIO;
+	writel((u32)data, regs + TN40_REG_MDIO_DATA);
+	/* read CMD_STAT until not busy */
+	ret = tn40_mdio_get(priv, &tmp_reg);
+	if (ret)
+		return -EIO;
+
+	if (TN40_GET_MDIO_RD_ERR(tmp_reg)) {
+		dev_err(&priv->pdev->dev, "MDIO error after write command\n");
+		return -EIO;
+	}
+	return 0;
+}
+
+static int tn40_mdio_read_cb(struct mii_bus *mii_bus, int addr, int devnum,
+			     int regnum)
+{
+	return tn40_mdio_read(mii_bus->priv, addr, devnum, regnum);
+}
+
+static int tn40_mdio_write_cb(struct mii_bus *mii_bus, int addr, int devnum,
+			      int regnum, u16 val)
+{
+	return  tn40_mdio_write(mii_bus->priv, addr, devnum, regnum, val);
+}
+
+int tn40_mdiobus_init(struct tn40_priv *priv)
+{
+	struct pci_dev *pdev = priv->pdev;
+	struct mii_bus *bus;
+	int ret;
+
+	bus = devm_mdiobus_alloc(&pdev->dev);
+	if (!bus)
+		return -ENOMEM;
+
+	bus->name = TN40_DRV_NAME;
+	bus->parent = &pdev->dev;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "tn40xx-%x-%x",
+		 pci_domain_nr(pdev->bus), pci_dev_id(pdev));
+	bus->priv = priv;
+
+	bus->read_c45 = tn40_mdio_read_cb;
+	bus->write_c45 = tn40_mdio_write_cb;
+
+	ret = devm_mdiobus_register(&pdev->dev, bus);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register mdiobus %d %u %u\n",
+			ret, bus->state, MDIOBUS_UNREGISTERED);
+		return ret;
+	}
+	tn40_mdio_set_speed(priv, TN40_MDIO_SPEED_6MHZ);
+	priv->mdio = bus;
+	return 0;
+}
-- 
2.34.1

Re: [PATCH net-next v5 5/6] net: tn40xx: add mdio bus support

[Hans-Frieder Vogt]

 > +static int tn40_mdio_read(struct tn40_priv *priv, int port, int device,
 > +              u16 regnum)
 > +{
 > +    void __iomem *regs = priv->regs;
 > +    u32 tmp_reg, i;
 > +
 > +    /* wait until MDIO is not busy */
 > +    if (tn40_mdio_get(priv, NULL))
 > +        return -EIO;
 > +
 > +    i = ((device & 0x1F) | ((port & 0x1F) << 5));

instead of using numbers for the masks, you may use here the constants
defined in uapi/linux/mdio.h, to make the code more understandable

i = (device & MDIO_PHY_ID_DEVAD) | ((port << 5) & MDIO_PHY_ID_PRTAD);

 > +    writel(i, regs + TN40_REG_MDIO_CMD);
 > +    writel((u32)regnum, regs + TN40_REG_MDIO_ADDR);
 > +    if (tn40_mdio_get(priv, NULL))
 > +        return -EIO;
 > +
 > +    writel(((1 << 15) | i), regs + TN40_REG_MDIO_CMD);

similarly here:

writel((MDIO_PHY_ID_C45 | i), regs + TN40_REG_MDIO_CMD);

 > +    /* read CMD_STAT until not busy */
 > +    if (tn40_mdio_get(priv, NULL))
 > +        return -EIO;
 > +
 > +    tmp_reg = readl(regs + TN40_REG_MDIO_DATA);
 > +    return lower_16_bits(tmp_reg);
 > +}
 > +
 > +static int tn40_mdio_write(struct tn40_priv *priv, int port, int device,
 > +               u16 regnum, u16 data)
 > +{
 > +    void __iomem *regs = priv->regs;
 > +    u32 tmp_reg = 0;
 > +    int ret;
 > +
 > +    /* wait until MDIO is not busy */
 > +    if (tn40_mdio_get(priv, NULL))
 > +        return -EIO;
 > +    writel(((device & 0x1F) | ((port & 0x1F) << 5)),

and also here, similarly:

writel((device & MDIO_PHY_ID_DEVAD) | ((port << 5) & MDIO_PHY_ID_PRTAD),

 > +           regs + TN40_REG_MDIO_CMD);
 > +    writel((u32)regnum, regs + TN40_REG_MDIO_ADDR);
 > +    if (tn40_mdio_get(priv, NULL))
 > +        return -EIO;
 > +    writel((u32)data, regs + TN40_REG_MDIO_DATA);
 > +    /* read CMD_STAT until not busy */
 > +    ret = tn40_mdio_get(priv, &tmp_reg);
 > +    if (ret)
 > +        return -EIO;
 > +
 > +    if (TN40_GET_MDIO_RD_ERR(tmp_reg)) {
 > +        dev_err(&priv->pdev->dev, "MDIO error after write command\n");
 > +        return -EIO;
 > +    }
 > +    return 0;
 > +}

--
Cheers,
Hans

Re: [PATCH net-next v5 5/6] net: tn40xx: add mdio bus support

[Andrew Lunn]

> > +    writel(((1 << 15) | i), regs + TN40_REG_MDIO_CMD);
> 
> similarly here:
> 
> writel((MDIO_PHY_ID_C45 | i), regs + TN40_REG_MDIO_CMD);

This one i don't agree with. It happens to work, but there is no
reason to think the hardware has been designed around how Linux
combines the different parts of a C45 address into one word, using the
top bit to indicate it is actually a C45 address, not a C22.

I would much prefer a TN40_ define is added for this bit.

> > +    writel(((device & 0x1F) | ((port & 0x1F) << 5)),
> 
> and also here, similarly:
> 
> writel((device & MDIO_PHY_ID_DEVAD) | ((port << 5) & MDIO_PHY_ID_PRTAD),

Similarly here, this happens to work, but that is just because the
hardware matches a software construct Linux uses. It would be better
to add TN40_ macros to describe the hardware.

   Andrew

Re: [PATCH net-next v5 5/6] net: tn40xx: add mdio bus support

[Hans-Frieder Vogt]

On 08.05.2024 20.25, Andrew Lunn wrote:
>>> +    writel(((1 << 15) | i), regs + TN40_REG_MDIO_CMD);
>> similarly here:
>>
>> writel((MDIO_PHY_ID_C45 | i), regs + TN40_REG_MDIO_CMD);
> This one i don't agree with. It happens to work, but there is no
> reason to think the hardware has been designed around how Linux
> combines the different parts of a C45 address into one word, using the
> top bit to indicate it is actually a C45 address, not a C22.
>
> I would much prefer a TN40_ define is added for this bit.
OK, yes, very valid point.
>
>>> +    writel(((device & 0x1F) | ((port & 0x1F) << 5)),
>> and also here, similarly:
>>
>> writel((device & MDIO_PHY_ID_DEVAD) | ((port << 5) & MDIO_PHY_ID_PRTAD),
> Similarly here, this happens to work, but that is just because the
> hardware matches a software construct Linux uses. It would be better
> to add TN40_ macros to describe the hardware.
agreed, I assume I just interpreted too much into the constants.
>
>     Andrew

Thanks!
Hans

Re: [PATCH net-next v5 5/6] net: tn40xx: add mdio bus support

[Hans-Frieder Vogt]

On 08.05.2024 21.30, Hans-Frieder Vogt wrote:

> On 08.05.2024 20.25, Andrew Lunn wrote:
>>>> +    writel(((1 << 15) | i), regs + TN40_REG_MDIO_CMD);
>>> similarly here:
>>>
>>> writel((MDIO_PHY_ID_C45 | i), regs + TN40_REG_MDIO_CMD);
>> This one i don't agree with. It happens to work, but there is no
>> reason to think the hardware has been designed around how Linux
>> combines the different parts of a C45 address into one word, using the
>> top bit to indicate it is actually a C45 address, not a C22.
>>
>> I would much prefer a TN40_ define is added for this bit.
> OK, yes, very valid point.

A small addition here:
digging through an old Tehuti linux river for the TN30xx (revision
7.33.5.1) I found revealing comments:
in bdx_mdio_read:
         /* Write read command */
         writel(MDIO_CMD_STAT_VAL(1, device, port), regs +
regMDIO_CMD_STAT);
in bdx_mdio_write:
         /* Write write command */
         writel(MDIO_CMD_STAT_VAL(0, device, port), regs +
regMDIO_CMD_STAT);

The CMD register has a different layout in the TN40xx, but the logic is
similar.
Therefore, I conclude now that the value (1 << 15)  is in fact a read
flag. Maybe it could be defined like:

#define TN40_MDIO_READ    BIT(15)

>>
>>>> +    writel(((device & 0x1F) | ((port & 0x1F) << 5)),
>>> and also here, similarly:
>>>
>>> writel((device & MDIO_PHY_ID_DEVAD) | ((port << 5) &
>>> MDIO_PHY_ID_PRTAD),
>> Similarly here, this happens to work, but that is just because the
>> hardware matches a software construct Linux uses. It would be better
>> to add TN40_ macros to describe the hardware.
> agreed, I assume I just interpreted too much into the constants.
>>
>>     Andrew
>
> Thanks!
> Hans
>
Thanks for challenging my initial assumptions,
Hans

Re: [PATCH net-next v5 5/6] net: tn40xx: add mdio bus support

[FUJITA Tomonori]

Hi,

On Thu, 9 May 2024 11:52:46 +0200
Hans-Frieder Vogt <hfdevel@gmx.net> wrote:

> A small addition here:
> digging through an old Tehuti linux river for the TN30xx (revision
> 7.33.5.1) I found revealing comments:
> in bdx_mdio_read:
>         /* Write read command */
>         writel(MDIO_CMD_STAT_VAL(1, device, port), regs +
> regMDIO_CMD_STAT);
> in bdx_mdio_write:
>         /* Write write command */
>         writel(MDIO_CMD_STAT_VAL(0, device, port), regs +
> regMDIO_CMD_STAT);
> 
> The CMD register has a different layout in the TN40xx, but the logic
> is
> similar.
> Therefore, I conclude now that the value (1 << 15)  is in fact a read
> flag. Maybe it could be defined like:
> 
> #define TN40_MDIO_READ    BIT(15)

Thanks a lot!

So worth adding MDIO_CMD_STAT_VAL macro and TN40_MDIO_CMD_READ
definition?


diff --git a/drivers/net/ethernet/tehuti/tn40_mdio.c b/drivers/net/ethernet/tehuti/tn40_mdio.c
index 64ef7f40f25d..d2e4b4d5ee9a 100644
--- a/drivers/net/ethernet/tehuti/tn40_mdio.c
+++ b/drivers/net/ethernet/tehuti/tn40_mdio.c
@@ -7,6 +7,10 @@
 
 #include "tn40.h"
 
+#define TN40_MDIO_CMD_STAT_VAL(device, port) \
+	(((device) & MDIO_PHY_ID_DEVAD) | (((port) << 5) & MDIO_PHY_ID_PRTAD))
+#define TN40_MDIO_CMD_READ BIT(15)
+
 static void tn40_mdio_set_speed(struct tn40_priv *priv, u32 speed)
 {
 	void __iomem *regs = priv->regs;
@@ -48,13 +52,13 @@ static int tn40_mdio_read(struct tn40_priv *priv, int port, int device,
 	if (tn40_mdio_get(priv, NULL))
 		return -EIO;
 
-	i = ((device & 0x1F) | ((port & 0x1F) << 5));
+	i = TN40_MDIO_CMD_STAT_VAL(device, port);
 	writel(i, regs + TN40_REG_MDIO_CMD);
 	writel((u32)regnum, regs + TN40_REG_MDIO_ADDR);
 	if (tn40_mdio_get(priv, NULL))
 		return -EIO;
 
-	writel(((1 << 15) | i), regs + TN40_REG_MDIO_CMD);
+	writel(TN40_MDIO_CMD_READ | i, regs + TN40_REG_MDIO_CMD);
 	/* read CMD_STAT until not busy */
 	if (tn40_mdio_get(priv, NULL))
 		return -EIO;
@@ -73,8 +77,7 @@ static int tn40_mdio_write(struct tn40_priv *priv, int port, int device,
 	/* wait until MDIO is not busy */
 	if (tn40_mdio_get(priv, NULL))
 		return -EIO;
-	writel(((device & 0x1F) | ((port & 0x1F) << 5)),
-	       regs + TN40_REG_MDIO_CMD);
+	writel(TN40_MDIO_CMD_STAT_VAL(device, port), regs + TN40_REG_MDIO_CMD);
 	writel((u32)regnum, regs + TN40_REG_MDIO_ADDR);
 	if (tn40_mdio_get(priv, NULL))
 		return -EIO;
-- 
2.34.1

Re: [PATCH net-next v5 5/6] net: tn40xx: add mdio bus support

[Hans-Frieder Vogt]

On 09.05.2024 12.59, FUJITA Tomonori wrote:
> Hi,
>
> On Thu, 9 May 2024 11:52:46 +0200
> Hans-Frieder Vogt <hfdevel@gmx.net> wrote:
>
>> A small addition here:
>> digging through an old Tehuti linux river for the TN30xx (revision
>> 7.33.5.1) I found revealing comments:
>> in bdx_mdio_read:
>>          /* Write read command */
>>          writel(MDIO_CMD_STAT_VAL(1, device, port), regs +
>> regMDIO_CMD_STAT);
>> in bdx_mdio_write:
>>          /* Write write command */
>>          writel(MDIO_CMD_STAT_VAL(0, device, port), regs +
>> regMDIO_CMD_STAT);
>>
>> The CMD register has a different layout in the TN40xx, but the logic
>> is
>> similar.
>> Therefore, I conclude now that the value (1 << 15)  is in fact a read
>> flag. Maybe it could be defined like:
>>
>> #define TN40_MDIO_READ    BIT(15)
> Thanks a lot!
>
> So worth adding MDIO_CMD_STAT_VAL macro and TN40_MDIO_CMD_READ
> definition?
>
>
> diff --git a/drivers/net/ethernet/tehuti/tn40_mdio.c b/drivers/net/ethernet/tehuti/tn40_mdio.c
> index 64ef7f40f25d..d2e4b4d5ee9a 100644
> --- a/drivers/net/ethernet/tehuti/tn40_mdio.c
> +++ b/drivers/net/ethernet/tehuti/tn40_mdio.c
> @@ -7,6 +7,10 @@
>
>   #include "tn40.h"
>
> +#define TN40_MDIO_CMD_STAT_VAL(device, port) \
> +	(((device) & MDIO_PHY_ID_DEVAD) | (((port) << 5) & MDIO_PHY_ID_PRTAD))

As Andrew pointed out, using the definitions from uapi/linux/mdio.h is a
bad idea, because it is just a coincidence that the definitions work in
this case.
So it is better to use specific defines for TN40xx, for example:

#define TN40_MDIO_DEVAD_MASK    0x001f
#define TN40_MDIO_PRTAD_MASK    0x03e0
#define TN40_MDIO_CMD_VAL(device, port) \
         (((device) & TN40_MDIO_DEVAD_MASK( | (((port) << 5) &
TN40_MDIO_PRTAD_MASK))

note that I left out the _STAT_ from the TN40_MDIO_CMD_VAL, because in
TN40xx the CMD and STAT registers are separate (different from the
TN30xx example).

> +#define TN40_MDIO_CMD_READ BIT(15)
> +
>   static void tn40_mdio_set_speed(struct tn40_priv *priv, u32 speed)
>   {
>   	void __iomem *regs = priv->regs;
> @@ -48,13 +52,13 @@ static int tn40_mdio_read(struct tn40_priv *priv, int port, int device,
>   	if (tn40_mdio_get(priv, NULL))
>   		return -EIO;
>
> -	i = ((device & 0x1F) | ((port & 0x1F) << 5));
> +	i = TN40_MDIO_CMD_STAT_VAL(device, port);
>   	writel(i, regs + TN40_REG_MDIO_CMD);
>   	writel((u32)regnum, regs + TN40_REG_MDIO_ADDR);
>   	if (tn40_mdio_get(priv, NULL))
>   		return -EIO;
>
> -	writel(((1 << 15) | i), regs + TN40_REG_MDIO_CMD);
> +	writel(TN40_MDIO_CMD_READ | i, regs + TN40_REG_MDIO_CMD);
>   	/* read CMD_STAT until not busy */
>   	if (tn40_mdio_get(priv, NULL))
>   		return -EIO;
> @@ -73,8 +77,7 @@ static int tn40_mdio_write(struct tn40_priv *priv, int port, int device,
>   	/* wait until MDIO is not busy */
>   	if (tn40_mdio_get(priv, NULL))
>   		return -EIO;
> -	writel(((device & 0x1F) | ((port & 0x1F) << 5)),
> -	       regs + TN40_REG_MDIO_CMD);
> +	writel(TN40_MDIO_CMD_STAT_VAL(device, port), regs + TN40_REG_MDIO_CMD);
>   	writel((u32)regnum, regs + TN40_REG_MDIO_ADDR);
>   	if (tn40_mdio_get(priv, NULL))
>   		return -EIO;

Thanks!
Hans

Re: [PATCH net-next v5 5/6] net: tn40xx: add mdio bus support

[FUJITA Tomonori]

Hi,

On Thu, 9 May 2024 13:16:11 +0200
Hans-Frieder Vogt <hfdevel@gmx.net> wrote:

> On 09.05.2024 12.59, FUJITA Tomonori wrote:
>> Hi,
>>
>> On Thu, 9 May 2024 11:52:46 +0200
>> Hans-Frieder Vogt <hfdevel@gmx.net> wrote:
>>
>>> A small addition here:
>>> digging through an old Tehuti linux river for the TN30xx (revision
>>> 7.33.5.1) I found revealing comments:
>>> in bdx_mdio_read:
>>>          /* Write read command */
>>>          writel(MDIO_CMD_STAT_VAL(1, device, port), regs +
>>> regMDIO_CMD_STAT);
>>> in bdx_mdio_write:
>>>          /* Write write command */
>>>          writel(MDIO_CMD_STAT_VAL(0, device, port), regs +
>>> regMDIO_CMD_STAT);
>>>
>>> The CMD register has a different layout in the TN40xx, but the logic
>>> is
>>> similar.
>>> Therefore, I conclude now that the value (1 << 15)  is in fact a read
>>> flag. Maybe it could be defined like:
>>>
>>> #define TN40_MDIO_READ    BIT(15)
>> Thanks a lot!
>>
>> So worth adding MDIO_CMD_STAT_VAL macro and TN40_MDIO_CMD_READ
>> definition?
>>
>>
>> diff --git a/drivers/net/ethernet/tehuti/tn40_mdio.c
>> b/drivers/net/ethernet/tehuti/tn40_mdio.c
>> index 64ef7f40f25d..d2e4b4d5ee9a 100644
>> --- a/drivers/net/ethernet/tehuti/tn40_mdio.c
>> +++ b/drivers/net/ethernet/tehuti/tn40_mdio.c
>> @@ -7,6 +7,10 @@
>>
>>   #include "tn40.h"
>>
>> +#define TN40_MDIO_CMD_STAT_VAL(device, port) \
>> + (((device) & MDIO_PHY_ID_DEVAD) | (((port) << 5) &
>> MDIO_PHY_ID_PRTAD))
> 
> As Andrew pointed out, using the definitions from uapi/linux/mdio.h is
> a
> bad idea, because it is just a coincidence that the definitions work
> in
> this case.

Ah, I misunderstood.


> So it is better to use specific defines for TN40xx, for example:
> 
> #define TN40_MDIO_DEVAD_MASK    0x001f
> #define TN40_MDIO_PRTAD_MASK    0x03e0
> #define TN40_MDIO_CMD_VAL(device, port) \
>         (((device) & TN40_MDIO_DEVAD_MASK( | (((port) << 5) &
> TN40_MDIO_PRTAD_MASK))
>
> note that I left out the _STAT_ from the TN40_MDIO_CMD_VAL, because in
> TN40xx the CMD and STAT registers are separate (different from the
> TN30xx example).

makes sense.

I'll add the followings:

#define TN40_MDIO_DEVAD_MASK GENMASK(4, 0)
#define TN40_MDIO_PRTAD_MASK GENMASK(9, 5)
#define TN40_MDIO_CMD_VAL(device, port) \
	(((device) & TN40_MDIO_DEVAD_MASK) | (FIELD_PREP(TN40_MDIO_PRTAD_MASK, (port))))
#define TN40_MDIO_CMD_READ BIT(15)