Re: [RFC PATCH 1/3] of: provide a binding for the 'fixed-link' property
From: Mark Rutland <mark.rutland@arm.com>
Date: 2013-07-23 11:22:59
Also in:
linux-arm-kernel, linux-devicetree
Hi Thomas, On Mon, Jul 15, 2013 at 04:34:08PM +0100, Thomas Petazzoni wrote:
quoted hunk ↗ jump to hunk
Some Ethernet MACs have a "fixed link", and are not connected to a normal MDIO-managed PHY device. For those situations, a Device Tree binding allows to describe a "fixed link", as a "fixed-link" property of the Ethernet device Device Tree node. This patch adds: * A documentation for the Device Tree property "fixed-link". * A of_phy_register_fixed_link() OF helper, which provided an OF node that contains a "fixed-link" property, registers the corresponding fixed PHY. * Removes the warning on the of_phy_connect_fixed_link() that says new drivers should not use it, since Grant Likely indicated that this "fixed-link" property is indeed the way to go. Signed-off-by: Thomas Petazzoni <redacted> --- .../devicetree/bindings/net/fixed-link.txt | 26 ++++++++++++++++ drivers/of/of_mdio.c | 36 +++++++++++++++++++--- include/linux/of_mdio.h | 10 ++++++ 3 files changed, 68 insertions(+), 4 deletions(-) create mode 100644 Documentation/devicetree/bindings/net/fixed-link.txtdiff --git a/Documentation/devicetree/bindings/net/fixed-link.txt b/Documentation/devicetree/bindings/net/fixed-link.txt new file mode 100644 index 0000000..25a009a --- /dev/null +++ b/Documentation/devicetree/bindings/net/fixed-link.txt@@ -0,0 +1,26 @@ +Fixed link Device Tree binding +------------------------------ + +Some Ethernet MACs have a "fixed link", and are not connected to a +normal MDIO-managed PHY device. For those situations, a Device Tree +binding allows to describe a "fixed link".
Are partictular MACs fixed link, or can some either be either fixed link or wired to an MDIO-managed PHY? i.e. can we assume a given MAC is fixed-link from its compatible string?
+ +Such a fixed link situation is described within an Ethernet device +Device Tree node using a 'fixed-link' property, composed of 5 +elements:
I'm not sure grouping these values together is the best way of handling this. It's rather opaque, and inflexible for future extension.
+ + 1. A fake PHY ID, which must be unique accross all fixed-link PHYs in + the system.
Is there any reason this couldn't be allocated dynamically within the kernel as needed? I don't see why an arbitrary unique value should be a dt binding requirement; it seems like a leak of Linux implementation details.
+ 2. The duplex (1 for full-duplex, 0 for half-duplex)
Will this change for a given MAC? Could we not have a boolean property for each of these, and require one to be present? Possibly fixed-link-full-duplex / fix-link-half-duplex?
+ 3. The speed (10, 100, 1000)
fixed-link-speed?
+ 4. The pause setting (1 for enabled, 0 for disabled) + 5. The asym pause setting (1 for enabled, 0 for disabled)
Boolean properties for both of these? Thanks, Mark.
quoted hunk ↗ jump to hunk
+ +Example: + +ethernet@0 { + ... + fixed-link = <1 1 1000 0 0>; + ... +}; +diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c index d5a57a9..66d5591 100644 --- a/drivers/of/of_mdio.c +++ b/drivers/of/of_mdio.c@@ -14,6 +14,7 @@ #include <linux/netdevice.h> #include <linux/err.h> #include <linux/phy.h> +#include <linux/phy_fixed.h> #include <linux/of.h> #include <linux/of_irq.h> #include <linux/of_mdio.h>@@ -215,10 +216,6 @@ EXPORT_SYMBOL(of_phy_connect); * @dev: pointer to net_device claiming the phy * @hndlr: Link state callback for the network device * @iface: PHY data interface type - * - * This function is a temporary stop-gap and will be removed soon. It is - * only to support the fs_enet, ucc_geth and gianfar Ethernet drivers. Do - * not call this function from new drivers. */ struct phy_device *of_phy_connect_fixed_link(struct net_device *dev, void (*hndlr)(struct net_device *),@@ -247,3 +244,34 @@ struct phy_device *of_phy_connect_fixed_link(struct net_device *dev, return IS_ERR(phy) ? NULL : phy; } EXPORT_SYMBOL(of_phy_connect_fixed_link); + +#if defined(CONFIG_FIXED_PHY) +/** + * of_phy_register_fixed_link - Parse fixed-link property and register a dummy phy + * @np: pointer to the OF device node that contains the "fixed-link" + * property for which a dummy phy should be registered. + */ +#define FIXED_LINK_PROPERTIES_COUNT 5 +int of_phy_register_fixed_link(struct device_node *np) +{ + struct fixed_phy_status status = {}; + u32 fixed_link_props[FIXED_LINK_PROPERTIES_COUNT]; + int ret; + + ret = of_property_read_u32_array(np, "fixed-link", + fixed_link_props, + FIXED_LINK_PROPERTIES_COUNT); + if (ret < 0) + return ret; + + status.link = 1; + status.duplex = fixed_link_props[1]; + status.speed = fixed_link_props[2]; + status.pause = fixed_link_props[3]; + status.asym_pause = fixed_link_props[4]; + + return fixed_phy_add(PHY_POLL, fixed_link_props[0], + &status); +} +EXPORT_SYMBOL(of_phy_register_fixed_link); +#endifdiff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h index 8163107..bf6efea 100644 --- a/include/linux/of_mdio.h +++ b/include/linux/of_mdio.h@@ -57,4 +57,14 @@ static inline struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np) } #endif /* CONFIG_OF */ +#if defined(CONFIG_OF) && defined(CONFIG_FIXED_PHY) +extern int of_phy_register_fixed_link(struct device_node *np); +#else +static inline int of_phy_register_fixed_link(struct device_node *np) +{ + return -ENOSYS; +} +#endif + + #endif /* __LINUX_OF_MDIO_H */-- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html