diff mbox series

[net-next,2/4] net: phy: realtek: add dt property to disable CLKOUT clock

Message ID 20210601090408.22025-3-qiangqing.zhang@nxp.com
State New
Headers show
Series net: phy: add dt property for realtek phy | expand

Commit Message

Joakim Zhang June 1, 2021, 9:04 a.m. UTC
Add "rtl821x,clkout-disable" property for user to disable CLKOUT clock
to save PHY power.

Per RTL8211F guide, a PHY reset should be issued after setting these
bits in PHYCR2 register. After this patch, CLKOUT clock output to be
disabled.

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
 drivers/net/phy/realtek.c | 48 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 47 insertions(+), 1 deletion(-)

Comments

Joakim Zhang June 2, 2021, 2:18 a.m. UTC | #1
Hi Russell,

Thanks for your reviewing.

> -----Original Message-----

> From: Russell King <linux@armlinux.org.uk>

> Sent: 2021年6月1日 19:49

> To: Joakim Zhang <qiangqing.zhang@nxp.com>

> Cc: davem@davemloft.net; kuba@kernel.org; robh+dt@kernel.org;

> andrew@lunn.ch; hkallweit1@gmail.com; f.fainelli@gmail.com; dl-linux-imx

> <linux-imx@nxp.com>; netdev@vger.kernel.org; devicetree@vger.kernel.org;

> linux-kernel@vger.kernel.org

> Subject: Re: [PATCH net-next 2/4] net: phy: realtek: add dt property to disable

> CLKOUT clock

> 

> On Tue, Jun 01, 2021 at 05:04:06PM +0800, Joakim Zhang wrote:

> > Add "rtl821x,clkout-disable" property for user to disable CLKOUT clock

> > to save PHY power.

> >

> > Per RTL8211F guide, a PHY reset should be issued after setting these

> > bits in PHYCR2 register. After this patch, CLKOUT clock output to be

> > disabled.

> >

> > Signed-off-by: Fugang Duan <fugang.duan@nxp.com>

> > Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>

> > ---

> >  drivers/net/phy/realtek.c | 48

> > ++++++++++++++++++++++++++++++++++++++-

> >  1 file changed, 47 insertions(+), 1 deletion(-)

> >

> > diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c

> > index 821e85a97367..4219c23ff2b0 100644

> > --- a/drivers/net/phy/realtek.c

> > +++ b/drivers/net/phy/realtek.c

> > @@ -8,6 +8,7 @@

> >   * Copyright (c) 2004 Freescale Semiconductor, Inc.

> >   */

> >  #include <linux/bitops.h>

> > +#include <linux/of.h>

> >  #include <linux/phy.h>

> >  #include <linux/module.h>

> >  #include <linux/delay.h>

> > @@ -27,6 +28,7 @@

> >  #define RTL821x_PAGE_SELECT			0x1f

> >

> >  #define RTL8211F_PHYCR1				0x18

> > +#define RTL8211F_PHYCR2				0x19

> >  #define RTL8211F_INSR				0x1d

> >

> >  #define RTL8211F_TX_DELAY			BIT(8)

> > @@ -40,6 +42,8 @@

> >  #define RTL8211E_TX_DELAY			BIT(12)

> >  #define RTL8211E_RX_DELAY			BIT(11)

> >

> > +#define RTL8211F_CLKOUT_EN			BIT(0)

> > +

> >  #define RTL8201F_ISR				0x1e

> >  #define RTL8201F_ISR_ANERR			BIT(15)

> >  #define RTL8201F_ISR_DUPLEX			BIT(13)

> > @@ -67,10 +71,17 @@

> >

> >  #define RTL_GENERIC_PHYID			0x001cc800

> >

> > +/* quirks for realtek phy */

> > +#define RTL821X_CLKOUT_DISABLE_FEATURE		BIT(0)

> > +

> >  MODULE_DESCRIPTION("Realtek PHY driver");

> MODULE_AUTHOR("Johnson

> > Leung");  MODULE_LICENSE("GPL");

> >

> > +struct rtl821x_priv {

> > +	u32 quirks;

> > +};

> > +

> >  static int rtl821x_read_page(struct phy_device *phydev)  {

> >  	return __phy_read(phydev, RTL821x_PAGE_SELECT); @@ -81,6 +92,23

> @@

> > static int rtl821x_write_page(struct phy_device *phydev, int page)

> >  	return __phy_write(phydev, RTL821x_PAGE_SELECT, page);  }

> >

> > +static int rtl821x_probe(struct phy_device *phydev) {

> > +	struct device *dev = &phydev->mdio.dev;

> > +	struct rtl821x_priv *priv;

> > +

> > +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);

> > +	if (!priv)

> > +		return -ENOMEM;

> > +

> > +	if (of_property_read_bool(dev->of_node, "rtl821x,clkout-disable"))

> > +		priv->quirks |= RTL821X_CLKOUT_DISABLE_FEATURE;

> > +

> > +	phydev->priv = priv;

> > +

> > +	return 0;

> > +}

> > +

> >  static int rtl8201_ack_interrupt(struct phy_device *phydev)  {

> >  	int err;

> > @@ -291,6 +319,7 @@ static int rtl8211c_config_init(struct phy_device

> > *phydev)

> >

> >  static int rtl8211f_config_init(struct phy_device *phydev)  {

> > +	struct rtl821x_priv *priv = phydev->priv;

> >  	struct device *dev = &phydev->mdio.dev;

> >  	u16 val_txdly, val_rxdly;

> >  	u16 val;

> > @@ -354,7 +383,23 @@ static int rtl8211f_config_init(struct phy_device

> *phydev)

> >  			val_rxdly ? "enabled" : "disabled");

> >  	}

> >

> > -	return 0;

> > +	if (priv->quirks & RTL821X_CLKOUT_DISABLE_FEATURE) {

> > +		ret = phy_modify_paged(phydev, 0xa43, RTL8211F_PHYCR2,

> > +				       RTL8211F_CLKOUT_EN, 0);

> > +		if (ret < 0) {

> > +			dev_err(&phydev->mdio.dev, "clkout disable failed\n");

> 

> You already have "dev" above, so this can be simplified to:

> 

> 			dev_err(dev, "clkout disable failed\n");

Yes. Will fix it.

> > +			return ret;

> > +		}

> > +	} else {

> > +		ret = phy_modify_paged(phydev, 0xa43, RTL8211F_PHYCR2,

> > +				       RTL8211F_CLKOUT_EN, RTL8211F_CLKOUT_EN);

> > +		if (ret < 0) {

> > +			dev_err(&phydev->mdio.dev, "clkout enable failed\n");

> 

> Same here.

Yes.

> > +			return ret;

> > +		}

> > +	}

> 

> Do you really need to distinguish between the enable and disable operation?

> Would the following be better?

> 

> 	if (priv->quirks & RTL821X_CLKOUT_DISABLE_FEATURE)

> 		clkout = 0;

> 	else

> 		clkout = RTL8211_CLKOUT_EN;

> 

> 	ret = phy_modify_paged(phydev, 0xa43, RTL8211F_PHYCR2,

> 			       RTL8211_CLKOUT_EN, clkout);

> 	if (ret < 0) {

> 		dev_err(dev, "clkout configuration failed: %pe\n",

> 			ERR_PTR(ret));

> 		return ret;

> 	}

Thanks, more clear, will improve it.

> Other questions:

> - Does the clock output default to enabled or disabled during kernel

>   boot without this patch? Does this state depend on the boot loader?

CLKOUT clock default is enabled after PHY reset. What the meaning of depending on the boot loader? I think also can enable it in boot loader.

> - Do we really need the use of negative logic here (which depends on

>   the answer to the above question)?

Yes, we need, Since the CLKOUT default is enabled, some board design may need this clock feed MAC, so we shouldn't
break existing design. 

> - Could other bits in the RTL8211F_PHYCR2 register also require future

>   configuration? Would it be better to store the desired PHYCR2

>   register value in "priv" rather than using "quirks". Quirks can become

>   very unweildy over time.

Make sense, it seems more universal.

> By way of example on the last point... probe() would become:

> 

> 	priv->phycr2 = RTL8211_CLKOUT_EN;

> 

> 	if (of_property_read_bool(dev->of_node, "rtl821x,clkout-disable"))

> 		priv->phycr2 &= ~RTL8211_CLKOUT_EN;

> 

> and config_init():

> 

> 	ret = phy_modify_paged(phydev, 0xa43, RTL8211F_PHYCR2,

> 			       RTL8211_CLKOUT_EN, priv->phycr2);

> 	if (ret < 0) {

> 		dev_err(dev, "clkout configuration failed: %pe\n",

> 			ERR_PTR(ret));

> 		return ret;

> 	}

> 

> Note that phycr2 would be a u16 value.

Thanks.

Best Regards,
Joakim Zhang
> Thanks.

> 

> --

> RMK's Patch system:

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> FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
Joakim Zhang June 2, 2021, 2:23 a.m. UTC | #2
Hi Andrew,

> -----Original Message-----

> From: Andrew Lunn <andrew@lunn.ch>

> Sent: 2021年6月2日 6:08

> To: Joakim Zhang <qiangqing.zhang@nxp.com>

> Cc: davem@davemloft.net; kuba@kernel.org; robh+dt@kernel.org;

> hkallweit1@gmail.com; linux@armlinux.org.uk; f.fainelli@gmail.com;

> dl-linux-imx <linux-imx@nxp.com>; netdev@vger.kernel.org;

> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org

> Subject: Re: [PATCH net-next 2/4] net: phy: realtek: add dt property to disable

> CLKOUT clock

> 

> > +struct rtl821x_priv {

> > +	u32 quirks;

> 

> I'm not sure quirks is the correct word here. I would probably use features, or

> flags.


Ok, I will change to flags.

As Russell king suggests another solution, which would you prefer to?
I need a conclusion so that I can send out the V2, thanks.

Best Regards,
Joakim Zhang
> 	  Andrew
diff mbox series

Patch

diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index 821e85a97367..4219c23ff2b0 100644
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -8,6 +8,7 @@ 
  * Copyright (c) 2004 Freescale Semiconductor, Inc.
  */
 #include <linux/bitops.h>
+#include <linux/of.h>
 #include <linux/phy.h>
 #include <linux/module.h>
 #include <linux/delay.h>
@@ -27,6 +28,7 @@ 
 #define RTL821x_PAGE_SELECT			0x1f
 
 #define RTL8211F_PHYCR1				0x18
+#define RTL8211F_PHYCR2				0x19
 #define RTL8211F_INSR				0x1d
 
 #define RTL8211F_TX_DELAY			BIT(8)
@@ -40,6 +42,8 @@ 
 #define RTL8211E_TX_DELAY			BIT(12)
 #define RTL8211E_RX_DELAY			BIT(11)
 
+#define RTL8211F_CLKOUT_EN			BIT(0)
+
 #define RTL8201F_ISR				0x1e
 #define RTL8201F_ISR_ANERR			BIT(15)
 #define RTL8201F_ISR_DUPLEX			BIT(13)
@@ -67,10 +71,17 @@ 
 
 #define RTL_GENERIC_PHYID			0x001cc800
 
+/* quirks for realtek phy */
+#define RTL821X_CLKOUT_DISABLE_FEATURE		BIT(0)
+
 MODULE_DESCRIPTION("Realtek PHY driver");
 MODULE_AUTHOR("Johnson Leung");
 MODULE_LICENSE("GPL");
 
+struct rtl821x_priv {
+	u32 quirks;
+};
+
 static int rtl821x_read_page(struct phy_device *phydev)
 {
 	return __phy_read(phydev, RTL821x_PAGE_SELECT);
@@ -81,6 +92,23 @@  static int rtl821x_write_page(struct phy_device *phydev, int page)
 	return __phy_write(phydev, RTL821x_PAGE_SELECT, page);
 }
 
+static int rtl821x_probe(struct phy_device *phydev)
+{
+	struct device *dev = &phydev->mdio.dev;
+	struct rtl821x_priv *priv;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	if (of_property_read_bool(dev->of_node, "rtl821x,clkout-disable"))
+		priv->quirks |= RTL821X_CLKOUT_DISABLE_FEATURE;
+
+	phydev->priv = priv;
+
+	return 0;
+}
+
 static int rtl8201_ack_interrupt(struct phy_device *phydev)
 {
 	int err;
@@ -291,6 +319,7 @@  static int rtl8211c_config_init(struct phy_device *phydev)
 
 static int rtl8211f_config_init(struct phy_device *phydev)
 {
+	struct rtl821x_priv *priv = phydev->priv;
 	struct device *dev = &phydev->mdio.dev;
 	u16 val_txdly, val_rxdly;
 	u16 val;
@@ -354,7 +383,23 @@  static int rtl8211f_config_init(struct phy_device *phydev)
 			val_rxdly ? "enabled" : "disabled");
 	}
 
-	return 0;
+	if (priv->quirks & RTL821X_CLKOUT_DISABLE_FEATURE) {
+		ret = phy_modify_paged(phydev, 0xa43, RTL8211F_PHYCR2,
+				       RTL8211F_CLKOUT_EN, 0);
+		if (ret < 0) {
+			dev_err(&phydev->mdio.dev, "clkout disable failed\n");
+			return ret;
+		}
+	} else {
+		ret = phy_modify_paged(phydev, 0xa43, RTL8211F_PHYCR2,
+				       RTL8211F_CLKOUT_EN, RTL8211F_CLKOUT_EN);
+		if (ret < 0) {
+			dev_err(&phydev->mdio.dev, "clkout enable failed\n");
+			return ret;
+		}
+	}
+
+	return genphy_soft_reset(phydev);
 }
 
 static int rtl8211e_config_init(struct phy_device *phydev)
@@ -847,6 +892,7 @@  static struct phy_driver realtek_drvs[] = {
 	}, {
 		PHY_ID_MATCH_EXACT(0x001cc916),
 		.name		= "RTL8211F Gigabit Ethernet",
+		.probe		= rtl821x_probe,
 		.config_init	= &rtl8211f_config_init,
 		.read_status	= rtlgen_read_status,
 		.config_intr	= &rtl8211f_config_intr,