Re: [PATCH NET V5 1/2] net: phy: Add phy loopback support in net phy framework

[Florian Fainelli]

On 06/25/2017 07:10 PM, Lin Yun Sheng wrote:
> This patch add set_loopback in phy_driver, which is used by Mac
> driver to enable or disable a phy. it also add a generic
> genphy_loopback function, which use BMCR loopback bit to enable
> or disable a phy.
> 
> Signed-off-by: Lin Yun Sheng 

Reviewed-by: Florian Fainelli 

[snip]

> +int phy_loopback(struct phy_device *phydev, bool enable)
> +{
> + struct phy_driver *phydrv = to_phy_driver(phydev->mdio.dev.driver);
> + int ret = 0;
> +
> + mutex_lock(>lock);
> +
> + if (enable && phydev->loopback_enabled) {
> + ret = -EBUSY;
> + goto out;
> + }
> +
> + if (!enable && !phydev->loopback_enabled) {
> + ret = -EINVAL;
> + goto out;
> + }

I am not sure if it is necessary to treat that condition as an error,
but I guess why not.
-- 
Florian

Re: [PATCH NET V5 1/2] net: phy: Add phy loopback support in net phy framework

[Andrew Lunn]

On Mon, Jun 26, 2017 at 10:10:38AM +0800, Lin Yun Sheng wrote:
> This patch add set_loopback in phy_driver, which is used by Mac
> driver to enable or disable a phy. it also add a generic
> genphy_loopback function, which use BMCR loopback bit to enable
> or disable a phy.
> 
> Signed-off-by: Lin Yun Sheng 

Reviewed-by: Andrew Lunn 

Andrew

[PATCH NET V5 1/2] net: phy: Add phy loopback support in net phy framework

[Lin Yun Sheng]

This patch add set_loopback in phy_driver, which is used by Mac
driver to enable or disable a phy. it also add a generic
genphy_loopback function, which use BMCR loopback bit to enable
or disable a phy.

Signed-off-by: Lin Yun Sheng 
---
 drivers/net/phy/marvell.c|  1 +
 drivers/net/phy/phy_device.c | 51 
 include/linux/phy.h  |  5 +
 3 files changed, 57 insertions(+)

diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
index 57297ba..01a1586 100644
--- a/drivers/net/phy/marvell.c
+++ b/drivers/net/phy/marvell.c
@@ -2094,6 +2094,7 @@ static int m88e1510_probe(struct phy_device *phydev)
.get_sset_count = marvell_get_sset_count,
.get_strings = marvell_get_strings,
.get_stats = marvell_get_stats,
+   .set_loopback = genphy_loopback,
},
{
.phy_id = MARVELL_PHY_ID_88E1540,
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 1219eea..1e08d62 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1123,6 +1123,39 @@ int phy_resume(struct phy_device *phydev)
 }
 EXPORT_SYMBOL(phy_resume);
 
+int phy_loopback(struct phy_device *phydev, bool enable)
+{
+   struct phy_driver *phydrv = to_phy_driver(phydev->mdio.dev.driver);
+   int ret = 0;
+
+   mutex_lock(>lock);
+
+   if (enable && phydev->loopback_enabled) {
+   ret = -EBUSY;
+   goto out;
+   }
+
+   if (!enable && !phydev->loopback_enabled) {
+   ret = -EINVAL;
+   goto out;
+   }
+
+   if (phydev->drv && phydrv->set_loopback)
+   ret = phydrv->set_loopback(phydev, enable);
+   else
+   ret = -EOPNOTSUPP;
+
+   if (ret)
+   goto out;
+
+   phydev->loopback_enabled = enable;
+
+out:
+   mutex_unlock(>lock);
+   return ret;
+}
+EXPORT_SYMBOL(phy_loopback);
+
 /* Generic PHY support and helper functions */
 
 /**
@@ -1628,6 +1661,23 @@ static int gen10g_resume(struct phy_device *phydev)
return 0;
 }
 
+int genphy_loopback(struct phy_device *phydev, bool enable)
+{
+   int value;
+
+   value = phy_read(phydev, MII_BMCR);
+   if (value < 0)
+   return value;
+
+   if (enable)
+   value |= BMCR_LOOPBACK;
+   else
+   value &= ~BMCR_LOOPBACK;
+
+   return phy_write(phydev, MII_BMCR, value);
+}
+EXPORT_SYMBOL(genphy_loopback);
+
 static int __set_phy_supported(struct phy_device *phydev, u32 max_speed)
 {
/* The default values for phydev->supported are provided by the PHY
@@ -1874,6 +1924,7 @@ void phy_drivers_unregister(struct phy_driver *drv, int n)
.read_status= genphy_read_status,
.suspend= genphy_suspend,
.resume = genphy_resume,
+   .set_loopback   = genphy_loopback,
 }, {
.phy_id = 0x,
.phy_id_mask= 0x,
diff --git a/include/linux/phy.h b/include/linux/phy.h
index e76e4ad..49c903dc 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -364,6 +364,7 @@ struct phy_c45_device_ids {
  * is_pseudo_fixed_link: Set to true if this phy is an Ethernet switch, etc.
  * has_fixups: Set to true if this phy has fixups/quirks.
  * suspended: Set to true if this phy has been suspended successfully.
+ * loopback_enabled: Set true if this phy has been loopbacked successfully.
  * state: state of the PHY for management purposes
  * dev_flags: Device-specific flags used by the PHY driver.
  * link_timeout: The number of timer firings to wait before the
@@ -400,6 +401,7 @@ struct phy_device {
bool is_pseudo_fixed_link;
bool has_fixups;
bool suspended;
+   bool loopback_enabled;
 
enum phy_state state;
 
@@ -639,6 +641,7 @@ struct phy_driver {
int (*set_tunable)(struct phy_device *dev,
struct ethtool_tunable *tuna,
const void *data);
+   int (*set_loopback)(struct phy_device *dev, bool enable);
 };
 #define to_phy_driver(d) container_of(to_mdio_common_driver(d),
\
  struct phy_driver, mdiodrv)
@@ -774,6 +777,7 @@ static inline void phy_device_free(struct phy_device 
*phydev) { }
 int phy_init_hw(struct phy_device *phydev);
 int phy_suspend(struct phy_device *phydev);
 int phy_resume(struct phy_device *phydev);
+int phy_loopback(struct phy_device *phydev, bool enable);
 struct phy_device *phy_attach(struct net_device *dev, const char *bus_id,
  phy_interface_t interface);
 struct phy_device *phy_find_first(struct mii_bus *bus);
@@ -825,6 +829,7 @@ void phy_attached_print(struct phy_device *phydev, const 
char *fmt, ...)
 int genphy_read_status(struct phy_device *phydev);
 int genphy_suspend(struct phy_device *phydev);
 int genphy_resume(struct phy_device