[net-next PATCH v6 1/3] net: phy: extend PHY package API to support multiple global address

[net-next PATCH v6 1/3] net: phy: extend PHY package API to support multiple global address

[Christian Marangi]

Current API for PHY package are limited to single address to configure
global settings for the PHY package.

It was found that some PHY package (for example the qca807x, a PHY
package that is shipped with a bundle of 5 PHY) requires multiple PHY
address to configure global settings. An example scenario is a PHY that
have a dedicated PHY for PSGMII/serdes calibrarion and have a specific
PHY in the package where the global PHY mode is set and affects every
other PHY in the package.

Change the API in the following way:
- Change phy_package_join() to take the base addr of the PHY package
  instead of the global PHY addr.
- Make __/phy_package_write/read() require an additional arg that
  select what global PHY address to use by passing the offset from the
  base addr passed on phy_package_join().

Each user of this API is updated to follow this new implementation
following a pattern where an enum is defined to declare the offset of the
addr.

We also drop the check if shared is defined as any user of the
phy_package_read/write is expected to use phy_package_join first. Misuse
of this will correctly trigger a kernel panic for NULL pointer
exception.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
Changes v2:
- Make kernel panic if shared is not init (bugged scenario)
- Fix some confusing comments

 drivers/net/phy/bcm54140.c       | 16 +++++++++----
 drivers/net/phy/mscc/mscc.h      |  5 ++++
 drivers/net/phy/mscc/mscc_main.c |  4 ++--
 drivers/net/phy/phy_device.c     | 35 ++++++++++++++-------------
 include/linux/phy.h              | 41 +++++++++++++++++++-------------
 5 files changed, 63 insertions(+), 38 deletions(-)

diff --git a/drivers/net/phy/bcm54140.c b/drivers/net/phy/bcm54140.c
index d43076592f81..2eea3d09b1e6 100644
--- a/drivers/net/phy/bcm54140.c
+++ b/drivers/net/phy/bcm54140.c
@@ -128,6 +128,10 @@
 #define BCM54140_DEFAULT_DOWNSHIFT 5
 #define BCM54140_MAX_DOWNSHIFT 9
 
+enum bcm54140_global_phy {
+	BCM54140_BASE_ADDR = 0,
+};
+
 struct bcm54140_priv {
 	int port;
 	int base_addr;
@@ -429,11 +433,13 @@ static int bcm54140_base_read_rdb(struct phy_device *phydev, u16 rdb)
 	int ret;
 
 	phy_lock_mdio_bus(phydev);
-	ret = __phy_package_write(phydev, MII_BCM54XX_RDB_ADDR, rdb);
+	ret = __phy_package_write(phydev, BCM54140_BASE_ADDR,
+				  MII_BCM54XX_RDB_ADDR, rdb);
 	if (ret < 0)
 		goto out;
 
-	ret = __phy_package_read(phydev, MII_BCM54XX_RDB_DATA);
+	ret = __phy_package_read(phydev, BCM54140_BASE_ADDR,
+				 MII_BCM54XX_RDB_DATA);
 
 out:
 	phy_unlock_mdio_bus(phydev);
@@ -446,11 +452,13 @@ static int bcm54140_base_write_rdb(struct phy_device *phydev,
 	int ret;
 
 	phy_lock_mdio_bus(phydev);
-	ret = __phy_package_write(phydev, MII_BCM54XX_RDB_ADDR, rdb);
+	ret = __phy_package_write(phydev, BCM54140_BASE_ADDR,
+				  MII_BCM54XX_RDB_ADDR, rdb);
 	if (ret < 0)
 		goto out;
 
-	ret = __phy_package_write(phydev, MII_BCM54XX_RDB_DATA, val);
+	ret = __phy_package_write(phydev, BCM54140_BASE_ADDR,
+				  MII_BCM54XX_RDB_DATA, val);
 
 out:
 	phy_unlock_mdio_bus(phydev);
diff --git a/drivers/net/phy/mscc/mscc.h b/drivers/net/phy/mscc/mscc.h
index 7a962050a4d4..6a3d8a754eb8 100644
--- a/drivers/net/phy/mscc/mscc.h
+++ b/drivers/net/phy/mscc/mscc.h
@@ -416,6 +416,11 @@ struct vsc8531_private {
  * gpio_lock: used for PHC operations. Common for all PHYs as the load/save GPIO
  * is shared.
  */
+
+enum vsc85xx_global_phy {
+	VSC88XX_BASE_ADDR = 0,
+};
+
 struct vsc85xx_shared_private {
 	struct mutex gpio_lock;
 };
diff --git a/drivers/net/phy/mscc/mscc_main.c b/drivers/net/phy/mscc/mscc_main.c
index 4171f01d34e5..6f74ce0ab1aa 100644
--- a/drivers/net/phy/mscc/mscc_main.c
+++ b/drivers/net/phy/mscc/mscc_main.c
@@ -711,7 +711,7 @@ int phy_base_write(struct phy_device *phydev, u32 regnum, u16 val)
 		dump_stack();
 	}
 
-	return __phy_package_write(phydev, regnum, val);
+	return __phy_package_write(phydev, VSC88XX_BASE_ADDR, regnum, val);
 }
 
 /* phydev->bus->mdio_lock should be locked when using this function */
@@ -722,7 +722,7 @@ int phy_base_read(struct phy_device *phydev, u32 regnum)
 		dump_stack();
 	}
 
-	return __phy_package_read(phydev, regnum);
+	return __phy_package_read(phydev, VSC88XX_BASE_ADDR, regnum);
 }
 
 u32 vsc85xx_csr_read(struct phy_device *phydev,
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 478126f6b5bc..424cbb13de13 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1648,20 +1648,22 @@ EXPORT_SYMBOL_GPL(phy_driver_is_genphy_10g);
 /**
  * phy_package_join - join a common PHY group
  * @phydev: target phy_device struct
- * @addr: cookie and PHY address for global register access
+ * @base_addr: cookie and base PHY address of PHY package for offset
+ *   calculation of global register access
  * @priv_size: if non-zero allocate this amount of bytes for private data
  *
  * This joins a PHY group and provides a shared storage for all phydevs in
  * this group. This is intended to be used for packages which contain
  * more than one PHY, for example a quad PHY transceiver.
  *
- * The addr parameter serves as a cookie which has to have the same value
- * for all members of one group and as a PHY address to access generic
- * registers of a PHY package. Usually, one of the PHY addresses of the
- * different PHYs in the package provides access to these global registers.
+ * The base_addr parameter serves as cookie which has to have the same values
+ * for all members of one group and as the base PHY address of the PHY package
+ * for offset calculation to access generic registers of a PHY package.
+ * Usually, one of the PHY addresses of the different PHYs in the package
+ * provides access to these global registers.
  * The address which is given here, will be used in the phy_package_read()
- * and phy_package_write() convenience functions. If your PHY doesn't have
- * global registers you can just pick any of the PHY addresses.
+ * and phy_package_write() convenience functions as base and added to the
+ * passed offset in those functions.
  *
  * This will set the shared pointer of the phydev to the shared storage.
  * If this is the first call for a this cookie the shared storage will be
@@ -1671,17 +1673,17 @@ EXPORT_SYMBOL_GPL(phy_driver_is_genphy_10g);
  * Returns < 1 on error, 0 on success. Esp. calling phy_package_join()
  * with the same cookie but a different priv_size is an error.
  */
-int phy_package_join(struct phy_device *phydev, int addr, size_t priv_size)
+int phy_package_join(struct phy_device *phydev, int base_addr, size_t priv_size)
 {
 	struct mii_bus *bus = phydev->mdio.bus;
 	struct phy_package_shared *shared;
 	int ret;
 
-	if (addr < 0 || addr >= PHY_MAX_ADDR)
+	if (base_addr < 0 || base_addr >= PHY_MAX_ADDR)
 		return -EINVAL;
 
 	mutex_lock(&bus->shared_lock);
-	shared = bus->shared[addr];
+	shared = bus->shared[base_addr];
 	if (!shared) {
 		ret = -ENOMEM;
 		shared = kzalloc(sizeof(*shared), GFP_KERNEL);
@@ -1693,9 +1695,9 @@ int phy_package_join(struct phy_device *phydev, int addr, size_t priv_size)
 				goto err_free;
 			shared->priv_size = priv_size;
 		}
-		shared->addr = addr;
+		shared->base_addr = base_addr;
 		refcount_set(&shared->refcnt, 1);
-		bus->shared[addr] = shared;
+		bus->shared[base_addr] = shared;
 	} else {
 		ret = -EINVAL;
 		if (priv_size && priv_size != shared->priv_size)
@@ -1733,7 +1735,7 @@ void phy_package_leave(struct phy_device *phydev)
 		return;
 
 	if (refcount_dec_and_mutex_lock(&shared->refcnt, &bus->shared_lock)) {
-		bus->shared[shared->addr] = NULL;
+		bus->shared[shared->base_addr] = NULL;
 		mutex_unlock(&bus->shared_lock);
 		kfree(shared->priv);
 		kfree(shared);
@@ -1752,7 +1754,8 @@ static void devm_phy_package_leave(struct device *dev, void *res)
  * devm_phy_package_join - resource managed phy_package_join()
  * @dev: device that is registering this PHY package
  * @phydev: target phy_device struct
- * @addr: cookie and PHY address for global register access
+ * @base_addr: cookie and base PHY address of PHY package for offset
+ *   calculation of global register access
  * @priv_size: if non-zero allocate this amount of bytes for private data
  *
  * Managed phy_package_join(). Shared storage fetched by this function,
@@ -1760,7 +1763,7 @@ static void devm_phy_package_leave(struct device *dev, void *res)
  * phy_package_join() for more information.
  */
 int devm_phy_package_join(struct device *dev, struct phy_device *phydev,
-			  int addr, size_t priv_size)
+			  int base_addr, size_t priv_size)
 {
 	struct phy_device **ptr;
 	int ret;
@@ -1770,7 +1773,7 @@ int devm_phy_package_join(struct device *dev, struct phy_device *phydev,
 	if (!ptr)
 		return -ENOMEM;
 
-	ret = phy_package_join(phydev, addr, priv_size);
+	ret = phy_package_join(phydev, base_addr, priv_size);
 
 	if (!ret) {
 		*ptr = phydev;
diff --git a/include/linux/phy.h b/include/linux/phy.h
index e5f1f41e399c..51702e349d83 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -327,7 +327,8 @@ struct mdio_bus_stats {
 
 /**
  * struct phy_package_shared - Shared information in PHY packages
- * @addr: Common PHY address used to combine PHYs in one package
+ * @base_addr: Base PHY address of PHY package used to combine PHYs
+ *   in one package and for offset calculation of phy_package_read/write
  * @refcnt: Number of PHYs connected to this shared data
  * @flags: Initialization of PHY package
  * @priv_size: Size of the shared private data @priv
@@ -338,7 +339,7 @@ struct mdio_bus_stats {
  * phy_package_leave().
  */
 struct phy_package_shared {
-	int addr;
+	int base_addr;
 	refcount_t refcnt;
 	unsigned long flags;
 	size_t priv_size;
@@ -1972,10 +1973,10 @@ int phy_ethtool_get_link_ksettings(struct net_device *ndev,
 int phy_ethtool_set_link_ksettings(struct net_device *ndev,
 				   const struct ethtool_link_ksettings *cmd);
 int phy_ethtool_nway_reset(struct net_device *ndev);
-int phy_package_join(struct phy_device *phydev, int addr, size_t priv_size);
+int phy_package_join(struct phy_device *phydev, int base_addr, size_t priv_size);
 void phy_package_leave(struct phy_device *phydev);
 int devm_phy_package_join(struct device *dev, struct phy_device *phydev,
-			  int addr, size_t priv_size);
+			  int base_addr, size_t priv_size);
 
 int __init mdio_bus_init(void);
 void mdio_bus_exit(void);
@@ -1998,46 +1999,54 @@ int __phy_hwtstamp_set(struct phy_device *phydev,
 		       struct kernel_hwtstamp_config *config,
 		       struct netlink_ext_ack *extack);
 
-static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
+static inline int phy_package_read(struct phy_device *phydev,
+				   unsigned int addr_offset, u32 regnum)
 {
 	struct phy_package_shared *shared = phydev->shared;
+	int addr = shared->base_addr + addr_offset;
 
-	if (!shared)
+	if (addr >= PHY_MAX_ADDR)
 		return -EIO;
 
-	return mdiobus_read(phydev->mdio.bus, shared->addr, regnum);
+	return mdiobus_read(phydev->mdio.bus, addr, regnum);
 }
 
-static inline int __phy_package_read(struct phy_device *phydev, u32 regnum)
+static inline int __phy_package_read(struct phy_device *phydev,
+				     unsigned int addr_offset, u32 regnum)
 {
 	struct phy_package_shared *shared = phydev->shared;
+	int addr = shared->base_addr + addr_offset;
 
-	if (!shared)
+	if (addr >= PHY_MAX_ADDR)
 		return -EIO;
 
-	return __mdiobus_read(phydev->mdio.bus, shared->addr, regnum);
+	return __mdiobus_read(phydev->mdio.bus, addr, regnum);
 }
 
 static inline int phy_package_write(struct phy_device *phydev,
-				    u32 regnum, u16 val)
+				    unsigned int addr_offset, u32 regnum,
+				    u16 val)
 {
 	struct phy_package_shared *shared = phydev->shared;
+	int addr = shared->base_addr + addr_offset;
 
-	if (!shared)
+	if (addr >= PHY_MAX_ADDR)
 		return -EIO;
 
-	return mdiobus_write(phydev->mdio.bus, shared->addr, regnum, val);
+	return mdiobus_write(phydev->mdio.bus, addr, regnum, val);
 }
 
 static inline int __phy_package_write(struct phy_device *phydev,
-				      u32 regnum, u16 val)
+				      unsigned int addr_offset, u32 regnum,
+				      u16 val)
 {
 	struct phy_package_shared *shared = phydev->shared;
+	int addr = shared->base_addr + addr_offset;
 
-	if (!shared)
+	if (addr >= PHY_MAX_ADDR)
 		return -EIO;
 
-	return __mdiobus_write(phydev->mdio.bus, shared->addr, regnum, val);
+	return __mdiobus_write(phydev->mdio.bus, addr, regnum, val);
 }
 
 static inline bool __phy_package_set_once(struct phy_device *phydev,
-- 
2.40.1

[net-next PATCH v6 2/3] net: phy: restructure __phy_write/read_mmd to helper and phydev user

[Christian Marangi]

Restructure phy_write_mmd and phy_read_mmd to implement generic helper
for direct mdiobus access for mmd and use these helper for phydev user.

This is needed in preparation of PHY package API that requires generic
access to the mdiobus and are deatched from phydev struct but instead
access them based on PHY package base_addr and offsets.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
Changes v3:
- Move to phy-core.c instead of inline in phy.h
Changes v2:
- Introduce this patch

 drivers/net/phy/phy-core.c | 64 ++++++++++++++++++--------------------
 1 file changed, 30 insertions(+), 34 deletions(-)

diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
index 966c93cbe616..b729ac8b2640 100644
--- a/drivers/net/phy/phy-core.c
+++ b/drivers/net/phy/phy-core.c
@@ -540,6 +540,28 @@ static void mmd_phy_indirect(struct mii_bus *bus, int phy_addr, int devad,
 			devad | MII_MMD_CTRL_NOINCR);
 }
 
+static int mmd_phy_read(struct mii_bus *bus, int phy_addr, bool is_c45,
+			int devad, u32 regnum)
+{
+	if (is_c45)
+		return __mdiobus_c45_read(bus, phy_addr, devad, regnum);
+
+	mmd_phy_indirect(bus, phy_addr, devad, regnum);
+	/* Read the content of the MMD's selected register */
+	return __mdiobus_read(bus, phy_addr, MII_MMD_DATA);
+}
+
+static int mmd_phy_write(struct mii_bus *bus, int phy_addr, bool is_c45,
+			 int devad, u32 regnum, u16 val)
+{
+	if (is_c45)
+		return __mdiobus_c45_write(bus, phy_addr, devad, regnum, val);
+
+	mmd_phy_indirect(bus, phy_addr, devad, regnum);
+	/* Write the data into MMD's selected register */
+	return __mdiobus_write(bus, phy_addr, MII_MMD_DATA, val);
+}
+
 /**
  * __phy_read_mmd - Convenience function for reading a register
  * from an MMD on a given PHY.
@@ -551,26 +573,14 @@ static void mmd_phy_indirect(struct mii_bus *bus, int phy_addr, int devad,
  */
 int __phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
 {
-	int val;
-
 	if (regnum > (u16)~0 || devad > 32)
 		return -EINVAL;
 
-	if (phydev->drv && phydev->drv->read_mmd) {
-		val = phydev->drv->read_mmd(phydev, devad, regnum);
-	} else if (phydev->is_c45) {
-		val = __mdiobus_c45_read(phydev->mdio.bus, phydev->mdio.addr,
-					 devad, regnum);
-	} else {
-		struct mii_bus *bus = phydev->mdio.bus;
-		int phy_addr = phydev->mdio.addr;
+	if (phydev->drv && phydev->drv->read_mmd)
+		return phydev->drv->read_mmd(phydev, devad, regnum);
 
-		mmd_phy_indirect(bus, phy_addr, devad, regnum);
-
-		/* Read the content of the MMD's selected register */
-		val = __mdiobus_read(bus, phy_addr, MII_MMD_DATA);
-	}
-	return val;
+	return mmd_phy_read(phydev->mdio.bus, phydev->mdio.addr,
+			    phydev->is_c45, devad, regnum);
 }
 EXPORT_SYMBOL(__phy_read_mmd);
 
@@ -607,28 +617,14 @@ EXPORT_SYMBOL(phy_read_mmd);
  */
 int __phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
 {
-	int ret;
-
 	if (regnum > (u16)~0 || devad > 32)
 		return -EINVAL;
 
-	if (phydev->drv && phydev->drv->write_mmd) {
-		ret = phydev->drv->write_mmd(phydev, devad, regnum, val);
-	} else if (phydev->is_c45) {
-		ret = __mdiobus_c45_write(phydev->mdio.bus, phydev->mdio.addr,
-					  devad, regnum, val);
-	} else {
-		struct mii_bus *bus = phydev->mdio.bus;
-		int phy_addr = phydev->mdio.addr;
+	if (phydev->drv && phydev->drv->write_mmd)
+		return phydev->drv->write_mmd(phydev, devad, regnum, val);
 
-		mmd_phy_indirect(bus, phy_addr, devad, regnum);
-
-		/* Write the data into MMD's selected register */
-		__mdiobus_write(bus, phy_addr, MII_MMD_DATA, val);
-
-		ret = 0;
-	}
-	return ret;
+	return mmd_phy_write(phydev->mdio.bus, phydev->mdio.addr,
+			     phydev->is_c45, devad, regnum, val);
 }
 EXPORT_SYMBOL(__phy_write_mmd);
 
-- 
2.40.1

Re: [net-next PATCH v6 2/3] net: phy: restructure __phy_write/read_mmd to helper and phydev user

[Russell King (Oracle)]

On Wed, Dec 13, 2023 at 11:57:29AM +0100, Christian Marangi wrote:
> Restructure phy_write_mmd and phy_read_mmd to implement generic helper
> for direct mdiobus access for mmd and use these helper for phydev user.
> 
> This is needed in preparation of PHY package API that requires generic
> access to the mdiobus and are deatched from phydev struct but instead
> access them based on PHY package base_addr and offsets.
> 
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Thanks!

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

[net-next PATCH v6 3/3] net: phy: add support for PHY package MMD read/write

[Christian Marangi]

Some PHY in PHY package may require to read/write MMD regs to correctly
configure the PHY package.

Add support for these additional required function in both lock and no
lock variant.

It's assumed that the entire PHY package is either C22 or C45. We use
C22 or C45 way of writing/reading to mmd regs based on the passed phydev
whether it's C22 or C45.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
Changes v6:
- Fix copy paste error for kdoc
Changes v5:
- Improve function description
Changes v4:
- Drop function comments in header file
Changes v3:
- Move in phy-core.c from phy.h
- Base c45 from phydev
Changes v2:
- Rework to use newly introduced helper
- Add common check for regnum and devad

 drivers/net/phy/phy-core.c | 144 +++++++++++++++++++++++++++++++++++++
 include/linux/phy.h        |  16 +++++
 2 files changed, 160 insertions(+)

diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
index b729ac8b2640..4c5927197557 100644
--- a/drivers/net/phy/phy-core.c
+++ b/drivers/net/phy/phy-core.c
@@ -650,6 +650,150 @@ int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
 }
 EXPORT_SYMBOL(phy_write_mmd);
 
+/**
+ * __phy_package_read_mmd - read MMD reg relative to PHY package base addr
+ * @phydev: The phy_device struct
+ * @addr_offset: The offset to be added to PHY package base_addr
+ * @devad: The MMD to read from
+ * @regnum: The register on the MMD to read
+ *
+ * Convenience helper for reading a register of an MMD on a given PHY
+ * using the PHY package base address. The base address is added to
+ * the addr_offset value.
+ *
+ * Same calling rules as for __phy_read();
+ *
+ * NOTE: It's assumed that the entire PHY package is either C22 or C45.
+ */
+int __phy_package_read_mmd(struct phy_device *phydev,
+			   unsigned int addr_offset, int devad,
+			   u32 regnum)
+{
+	struct phy_package_shared *shared = phydev->shared;
+	int addr = shared->base_addr + addr_offset;
+
+	if (addr >= PHY_MAX_ADDR)
+		return -EIO;
+
+	if (regnum > (u16)~0 || devad > 32)
+		return -EINVAL;
+
+	return mmd_phy_read(phydev->mdio.bus, addr, phydev->is_c45, devad,
+			    regnum);
+}
+EXPORT_SYMBOL(__phy_package_read_mmd);
+
+/**
+ * phy_package_read_mmd - read MMD reg relative to PHY package base addr
+ * @phydev: The phy_device struct
+ * @addr_offset: The offset to be added to PHY package base_addr
+ * @devad: The MMD to read from
+ * @regnum: The register on the MMD to read
+ *
+ * Convenience helper for reading a register of an MMD on a given PHY
+ * using the PHY package base address. The base address is added to
+ * the addr_offset value.
+ *
+ * Same calling rules as for phy_read();
+ *
+ * NOTE: It's assumed that the entire PHY package is either C22 or C45.
+ */
+int phy_package_read_mmd(struct phy_device *phydev,
+			 unsigned int addr_offset, int devad,
+			 u32 regnum)
+{
+	struct phy_package_shared *shared = phydev->shared;
+	int addr = shared->base_addr + addr_offset;
+	int val;
+
+	if (addr >= PHY_MAX_ADDR)
+		return -EIO;
+
+	if (regnum > (u16)~0 || devad > 32)
+		return -EINVAL;
+
+	phy_lock_mdio_bus(phydev);
+	val = mmd_phy_read(phydev->mdio.bus, addr, phydev->is_c45, devad,
+			   regnum);
+	phy_unlock_mdio_bus(phydev);
+
+	return val;
+}
+EXPORT_SYMBOL(phy_package_read_mmd);
+
+/**
+ * __phy_package_write_mmd - write MMD reg relative to PHY package base addr
+ * @phydev: The phy_device struct
+ * @addr_offset: The offset to be added to PHY package base_addr
+ * @devad: The MMD to write to
+ * @regnum: The register on the MMD to write
+ * @val: value to write to @regnum
+ *
+ * Convenience helper for writing a register of an MMD on a given PHY
+ * using the PHY package base address. The base address is added to
+ * the addr_offset value.
+ *
+ * Same calling rules as for __phy_write();
+ *
+ * NOTE: It's assumed that the entire PHY package is either C22 or C45.
+ */
+int __phy_package_write_mmd(struct phy_device *phydev,
+			    unsigned int addr_offset, int devad,
+			    u32 regnum, u16 val)
+{
+	struct phy_package_shared *shared = phydev->shared;
+	int addr = shared->base_addr + addr_offset;
+
+	if (addr >= PHY_MAX_ADDR)
+		return -EIO;
+
+	if (regnum > (u16)~0 || devad > 32)
+		return -EINVAL;
+
+	return mmd_phy_write(phydev->mdio.bus, addr, phydev->is_c45, devad,
+			     regnum, val);
+}
+EXPORT_SYMBOL(__phy_package_write_mmd);
+
+/**
+ * phy_package_write_mmd - write MMD reg relative to PHY package base addr
+ * @phydev: The phy_device struct
+ * @addr_offset: The offset to be added to PHY package base_addr
+ * @devad: The MMD to write to
+ * @regnum: The register on the MMD to write
+ * @val: value to write to @regnum
+ *
+ * Convenience helper for writing a register of an MMD on a given PHY
+ * using the PHY package base address. The base address is added to
+ * the addr_offset value.
+ *
+ * Same calling rules as for phy_write();
+ *
+ * NOTE: It's assumed that the entire PHY package is either C22 or C45.
+ */
+int phy_package_write_mmd(struct phy_device *phydev,
+			  unsigned int addr_offset, int devad,
+			  u32 regnum, u16 val)
+{
+	struct phy_package_shared *shared = phydev->shared;
+	int addr = shared->base_addr + addr_offset;
+	int ret;
+
+	if (addr >= PHY_MAX_ADDR)
+		return -EIO;
+
+	if (regnum > (u16)~0 || devad > 32)
+		return -EINVAL;
+
+	phy_lock_mdio_bus(phydev);
+	ret = mmd_phy_write(phydev->mdio.bus, addr, phydev->is_c45, devad,
+			    regnum, val);
+	phy_unlock_mdio_bus(phydev);
+
+	return ret;
+}
+EXPORT_SYMBOL(phy_package_write_mmd);
+
 /**
  * phy_modify_changed - Function for modifying a PHY register
  * @phydev: the phy_device struct
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 51702e349d83..f58a9ff52e0d 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -2049,6 +2049,22 @@ static inline int __phy_package_write(struct phy_device *phydev,
 	return __mdiobus_write(phydev->mdio.bus, addr, regnum, val);
 }
 
+int __phy_package_read_mmd(struct phy_device *phydev,
+			   unsigned int addr_offset, int devad,
+			   u32 regnum);
+
+int phy_package_read_mmd(struct phy_device *phydev,
+			 unsigned int addr_offset, int devad,
+			 u32 regnum);
+
+int __phy_package_write_mmd(struct phy_device *phydev,
+			    unsigned int addr_offset, int devad,
+			    u32 regnum, u16 val);
+
+int phy_package_write_mmd(struct phy_device *phydev,
+			  unsigned int addr_offset, int devad,
+			  u32 regnum, u16 val);
+
 static inline bool __phy_package_set_once(struct phy_device *phydev,
 					  unsigned int b)
 {
-- 
2.40.1

Re: [net-next PATCH v6 3/3] net: phy: add support for PHY package MMD read/write

[Russell King (Oracle)]

On Wed, Dec 13, 2023 at 11:57:30AM +0100, Christian Marangi wrote:
> Some PHY in PHY package may require to read/write MMD regs to correctly
> configure the PHY package.
> 
> Add support for these additional required function in both lock and no
> lock variant.
> 
> It's assumed that the entire PHY package is either C22 or C45. We use
> C22 or C45 way of writing/reading to mmd regs based on the passed phydev
> whether it's C22 or C45.
> 
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

I don't recall what has been said in previous postings of this, but
introducing new helpers without an example user is normally frowned
upon. The lack of cover message for this three patch series also
doesn't help (the cover message could explain why there's no users
being proposed with this addition of helpers.)

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Re: [net-next PATCH v6 3/3] net: phy: add support for PHY package MMD read/write

[Christian Marangi]

On Wed, Dec 13, 2023 at 03:47:19PM +0000, Russell King (Oracle) wrote:
> On Wed, Dec 13, 2023 at 11:57:30AM +0100, Christian Marangi wrote:
> > Some PHY in PHY package may require to read/write MMD regs to correctly
> > configure the PHY package.
> > 
> > Add support for these additional required function in both lock and no
> > lock variant.
> > 
> > It's assumed that the entire PHY package is either C22 or C45. We use
> > C22 or C45 way of writing/reading to mmd regs based on the passed phydev
> > whether it's C22 or C45.
> > 
> > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> 
> I don't recall what has been said in previous postings of this, but
> introducing new helpers without an example user is normally frowned
> upon. The lack of cover message for this three patch series also
> doesn't help (the cover message could explain why there's no users
> being proposed with this addition of helpers.)
>

These are prereq for the qca803x PHY driver and the PHY package series.

I can move this single patch in those series, but it was suggested to
move these simple change to a separate patch to lower the patch number
since they were orthogonal to the PHY package series proposal.

-- 
	Ansuel

Re: [net-next PATCH v6 3/3] net: phy: add support for PHY package MMD read/write

[Russell King (Oracle)]

On Wed, Dec 13, 2023 at 04:55:08PM +0100, Christian Marangi wrote:
> On Wed, Dec 13, 2023 at 03:47:19PM +0000, Russell King (Oracle) wrote:
> > On Wed, Dec 13, 2023 at 11:57:30AM +0100, Christian Marangi wrote:
> > > Some PHY in PHY package may require to read/write MMD regs to correctly
> > > configure the PHY package.
> > > 
> > > Add support for these additional required function in both lock and no
> > > lock variant.
> > > 
> > > It's assumed that the entire PHY package is either C22 or C45. We use
> > > C22 or C45 way of writing/reading to mmd regs based on the passed phydev
> > > whether it's C22 or C45.
> > > 
> > > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> > 
> > I don't recall what has been said in previous postings of this, but
> > introducing new helpers without an example user is normally frowned
> > upon. The lack of cover message for this three patch series also
> > doesn't help (the cover message could explain why there's no users
> > being proposed with this addition of helpers.)
> >
> 
> These are prereq for the qca803x PHY driver and the PHY package series.
> 
> I can move this single patch in those series, but it was suggested to
> move these simple change to a separate patch to lower the patch number
> since they were orthogonal to the PHY package series proposal.

... so adding a cover message (your series in general seem to lack
those) would be a good idea to explain that.

-- 
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Re: [net-next PATCH v6 3/3] net: phy: add support for PHY package MMD read/write

[Christian Marangi]

On Wed, Dec 13, 2023 at 04:13:28PM +0000, Russell King (Oracle) wrote:
> On Wed, Dec 13, 2023 at 04:55:08PM +0100, Christian Marangi wrote:
> > On Wed, Dec 13, 2023 at 03:47:19PM +0000, Russell King (Oracle) wrote:
> > > On Wed, Dec 13, 2023 at 11:57:30AM +0100, Christian Marangi wrote:
> > > > Some PHY in PHY package may require to read/write MMD regs to correctly
> > > > configure the PHY package.
> > > > 
> > > > Add support for these additional required function in both lock and no
> > > > lock variant.
> > > > 
> > > > It's assumed that the entire PHY package is either C22 or C45. We use
> > > > C22 or C45 way of writing/reading to mmd regs based on the passed phydev
> > > > whether it's C22 or C45.
> > > > 
> > > > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> > > 
> > > I don't recall what has been said in previous postings of this, but
> > > introducing new helpers without an example user is normally frowned
> > > upon. The lack of cover message for this three patch series also
> > > doesn't help (the cover message could explain why there's no users
> > > being proposed with this addition of helpers.)
> > >
> > 
> > These are prereq for the qca803x PHY driver and the PHY package series.
> > 
> > I can move this single patch in those series, but it was suggested to
> > move these simple change to a separate patch to lower the patch number
> > since they were orthogonal to the PHY package series proposal.
> 
> ... so adding a cover message (your series in general seem to lack
> those) would be a good idea to explain that.
>

I tend to use cover letters only for big series, sorry for not being
very clear about this. Soo should I detach this from here or it O.K.?

-- 
	Ansuel

Re: [net-next PATCH v6 3/3] net: phy: add support for PHY package MMD read/write

[Jakub Kicinski]

On Wed, 13 Dec 2023 17:26:43 +0100 Christian Marangi wrote:
> I tend to use cover letters only for big series, sorry for not being
> very clear about this.

FWIW in netdev the rule of thumb is "if there's more than 2 patches,
there's probably extra context". Even the 2 patch exception for cover
letters is mostly for when people post code + test, as two separate
patches. Cover letter stating that you have a series for xyz
pending, which will need this, seems like a straightforward ask..

Re: [net-next PATCH v6 1/3] net: phy: extend PHY package API to support multiple global address

[Russell King (Oracle)]

On Wed, Dec 13, 2023 at 11:57:28AM +0100, Christian Marangi wrote:
> -static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
> +static inline int phy_package_read(struct phy_device *phydev,
> +				   unsigned int addr_offset, u32 regnum)
>  {
>  	struct phy_package_shared *shared = phydev->shared;
> +	int addr = shared->base_addr + addr_offset;
>  
> -	if (!shared)
> +	if (addr >= PHY_MAX_ADDR)
>  		return -EIO;

If we're going to check the address, I think we should check it
properly, which means also checking whether it's become negative.

Alternatively, we could consider making "addr" and "base_addr"
unsigned types, since they should never be negative. However,
that probably should be done as a separate patch before this one.

Thanks.

-- 
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Re: [net-next PATCH v6 1/3] net: phy: extend PHY package API to support multiple global address

[Christian Marangi]

On Wed, Dec 13, 2023 at 03:45:24PM +0000, Russell King (Oracle) wrote:
> On Wed, Dec 13, 2023 at 11:57:28AM +0100, Christian Marangi wrote:
> > -static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
> > +static inline int phy_package_read(struct phy_device *phydev,
> > +				   unsigned int addr_offset, u32 regnum)
> >  {
> >  	struct phy_package_shared *shared = phydev->shared;
> > +	int addr = shared->base_addr + addr_offset;
> >  
> > -	if (!shared)
> > +	if (addr >= PHY_MAX_ADDR)
> >  		return -EIO;
> 
> If we're going to check the address, I think we should check it
> properly, which means also checking whether it's become negative.
> 
> Alternatively, we could consider making "addr" and "base_addr"
> unsigned types, since they should never be negative. However,
> that probably should be done as a separate patch before this one.
>

Maybe I'm confused but isn't already like that?
On phy_package_join base_addr is already checked if it's negative (and
rejected)

addr_offset is unsigned so it can't be negative.

We can switch addr to unsigned just for the sake of it but if I'm not
wrong all the sanity check are already done.

-- 
	Ansuel

Re: [net-next PATCH v6 1/3] net: phy: extend PHY package API to support multiple global address

[Russell King (Oracle)]

On Wed, Dec 13, 2023 at 04:50:33PM +0100, Christian Marangi wrote:
> On Wed, Dec 13, 2023 at 03:45:24PM +0000, Russell King (Oracle) wrote:
> > On Wed, Dec 13, 2023 at 11:57:28AM +0100, Christian Marangi wrote:
> > > -static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
> > > +static inline int phy_package_read(struct phy_device *phydev,
> > > +				   unsigned int addr_offset, u32 regnum)
> > >  {
> > >  	struct phy_package_shared *shared = phydev->shared;
> > > +	int addr = shared->base_addr + addr_offset;
> > >  
> > > -	if (!shared)
> > > +	if (addr >= PHY_MAX_ADDR)
> > >  		return -EIO;
> > 
> > If we're going to check the address, I think we should check it
> > properly, which means also checking whether it's become negative.
> > 
> > Alternatively, we could consider making "addr" and "base_addr"
> > unsigned types, since they should never be negative. However,
> > that probably should be done as a separate patch before this one.
> >
> 
> Maybe I'm confused but isn't already like that?
> On phy_package_join base_addr is already checked if it's negative (and
> rejected)
> 
> addr_offset is unsigned so it can't be negative.

True, but with base_addr being an int, addr_offset being unsigned int,
and addr being an int, if addr_offset is a very large number,
2-complement arithmetic will have the effect of treating it as a
negative number.

So, base_addr=0, addr_offset=~0 results in addr being -1.

If "addr" were unsigned int, and as we've already established,
"base_addr" can't be less than zero because of the checks already done
(thus it can also be unsigned int) then we'll end up with the checks
you're adding automatically doing the right thing, because...

base_addr=0, addr_offset=~0 results in addr being ~0 (a large
positive unsigned number).

-- 
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Re: [net-next PATCH v6 1/3] net: phy: extend PHY package API to support multiple global address

[Christian Marangi]

On Wed, Dec 13, 2023 at 04:12:24PM +0000, Russell King (Oracle) wrote:
> On Wed, Dec 13, 2023 at 04:50:33PM +0100, Christian Marangi wrote:
> > On Wed, Dec 13, 2023 at 03:45:24PM +0000, Russell King (Oracle) wrote:
> > > On Wed, Dec 13, 2023 at 11:57:28AM +0100, Christian Marangi wrote:
> > > > -static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
> > > > +static inline int phy_package_read(struct phy_device *phydev,
> > > > +				   unsigned int addr_offset, u32 regnum)
> > > >  {
> > > >  	struct phy_package_shared *shared = phydev->shared;
> > > > +	int addr = shared->base_addr + addr_offset;
> > > >  
> > > > -	if (!shared)
> > > > +	if (addr >= PHY_MAX_ADDR)
> > > >  		return -EIO;
> > > 
> > > If we're going to check the address, I think we should check it
> > > properly, which means also checking whether it's become negative.
> > > 
> > > Alternatively, we could consider making "addr" and "base_addr"
> > > unsigned types, since they should never be negative. However,
> > > that probably should be done as a separate patch before this one.
> > >
> > 
> > Maybe I'm confused but isn't already like that?
> > On phy_package_join base_addr is already checked if it's negative (and
> > rejected)
> > 
> > addr_offset is unsigned so it can't be negative.
> 
> True, but with base_addr being an int, addr_offset being unsigned int,
> and addr being an int, if addr_offset is a very large number,
> 2-complement arithmetic will have the effect of treating it as a
> negative number.
> 
> So, base_addr=0, addr_offset=~0 results in addr being -1.
> 
> If "addr" were unsigned int, and as we've already established,
> "base_addr" can't be less than zero because of the checks already done
> (thus it can also be unsigned int) then we'll end up with the checks
> you're adding automatically doing the right thing, because...
> 
> base_addr=0, addr_offset=~0 results in addr being ~0 (a large
> positive unsigned number).
> 

Oh ok... now it makes sense. So I guess I should change "addr" to
unsigned.

Considering I'm changing addr in phy_package_shared to base_addr would
it be ok to change that also to unsigned (doesn't make sense to have
that int) in this patch? Or should I create first a small patch before
this to change addr type?

-- 
	Ansuel

Re: [net-next PATCH v6 1/3] net: phy: extend PHY package API to support multiple global address

[Russell King (Oracle)]

On Wed, Dec 13, 2023 at 05:24:18PM +0100, Christian Marangi wrote:
> On Wed, Dec 13, 2023 at 04:12:24PM +0000, Russell King (Oracle) wrote:
> > On Wed, Dec 13, 2023 at 04:50:33PM +0100, Christian Marangi wrote:
> > > On Wed, Dec 13, 2023 at 03:45:24PM +0000, Russell King (Oracle) wrote:
> > > > On Wed, Dec 13, 2023 at 11:57:28AM +0100, Christian Marangi wrote:
> > > > > -static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
> > > > > +static inline int phy_package_read(struct phy_device *phydev,
> > > > > +				   unsigned int addr_offset, u32 regnum)
> > > > >  {
> > > > >  	struct phy_package_shared *shared = phydev->shared;
> > > > > +	int addr = shared->base_addr + addr_offset;
> > > > >  
> > > > > -	if (!shared)
> > > > > +	if (addr >= PHY_MAX_ADDR)
> > > > >  		return -EIO;
> > > > 
> > > > If we're going to check the address, I think we should check it
> > > > properly, which means also checking whether it's become negative.
> > > > 
> > > > Alternatively, we could consider making "addr" and "base_addr"
> > > > unsigned types, since they should never be negative. However,
> > > > that probably should be done as a separate patch before this one.
> > > >
> > > 
> > > Maybe I'm confused but isn't already like that?
> > > On phy_package_join base_addr is already checked if it's negative (and
> > > rejected)
> > > 
> > > addr_offset is unsigned so it can't be negative.
> > 
> > True, but with base_addr being an int, addr_offset being unsigned int,
> > and addr being an int, if addr_offset is a very large number,
> > 2-complement arithmetic will have the effect of treating it as a
> > negative number.
> > 
> > So, base_addr=0, addr_offset=~0 results in addr being -1.
> > 
> > If "addr" were unsigned int, and as we've already established,
> > "base_addr" can't be less than zero because of the checks already done
> > (thus it can also be unsigned int) then we'll end up with the checks
> > you're adding automatically doing the right thing, because...
> > 
> > base_addr=0, addr_offset=~0 results in addr being ~0 (a large
> > positive unsigned number).
> > 
> 
> Oh ok... now it makes sense. So I guess I should change "addr" to
> unsigned.
> 
> Considering I'm changing addr in phy_package_shared to base_addr would
> it be ok to change that also to unsigned (doesn't make sense to have
> that int) in this patch? Or should I create first a small patch before
> this to change addr type?

What I said when I mooted the use of unsigned was:

"Alternatively, we could consider making "addr" and "base_addr"
 unsigned types, since they should never be negative. However,
 that probably should be done as a separate patch before this
 one."

so my thoughts are that it should be a separate small patch - it's a
single logical change.

Thanks.

-- 
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