path: root/Documentation
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authorLinus Torvalds <torvalds@linux-foundation.org>2008-04-25 12:28:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-25 12:28:28 -0700
commit2e561c7b7e705b619122e5386d6f99f28f2b6e5a (patch)
treebe942c58cacd25c66cced37e1a82f269c37871de /Documentation
parent2cfed60cc24676d65e01278dbf10d0069de02592 (diff)
parent653252c2302cdf2dfbca66a7e177f7db783f9efa (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (48 commits) net: Fix wrong interpretation of some copy_to_user() results. xfrm: alg_key_len & alg_icv_len should be unsigned [netdrvr] tehuti: move ioctl perm check closer to function start ipv6: Fix typo in net/ipv6/Kconfig via-velocity: fix vlan receipt tg3: sparse cleanup forcedeth: realtek phy crossover detection ibm_newemac: Increase MDIO timeouts gianfar: Fix skb allocation strategy netxen: reduce stack usage of netxen_nic_flash_print smc911x: test after postfix decrement fails in smc911x_{reset,drop_pkt} net drivers: fix platform driver hotplug/coldplug forcedeth: new backoff implementation ehea: make things static phylib: Add support for board-level PHY fixups [netdrvr] atlx: code movement: move atl1 parameter parsing atlx: remove flash vendor parameter korina: misc cleanup korina: fix misplaced return statement WAN: Fix confusing insmod error code for C101 too. ...
Diffstat (limited to 'Documentation')
1 files changed, 37 insertions, 1 deletions
diff --git a/Documentation/networking/phy.txt b/Documentation/networking/phy.txt
index 0bc95eab1512..8df6a7b0e66c 100644
--- a/Documentation/networking/phy.txt
+++ b/Documentation/networking/phy.txt
@@ -1,7 +1,7 @@
PHY Abstraction Layer
-(Updated 2006-11-30)
+(Updated 2008-04-08)
@@ -291,3 +291,39 @@ Writing a PHY driver
Feel free to look at the Marvell, Cicada, and Davicom drivers in
drivers/net/phy/ for examples (the lxt and qsemi drivers have
not been tested as of this writing)
+Board Fixups
+ Sometimes the specific interaction between the platform and the PHY requires
+ special handling. For instance, to change where the PHY's clock input is,
+ or to add a delay to account for latency issues in the data path. In order
+ to support such contingencies, the PHY Layer allows platform code to register
+ fixups to be run when the PHY is brought up (or subsequently reset).
+ When the PHY Layer brings up a PHY it checks to see if there are any fixups
+ registered for it, matching based on UID (contained in the PHY device's phy_id
+ field) and the bus identifier (contained in phydev->dev.bus_id). Both must
+ match, however two constants, PHY_ANY_ID and PHY_ANY_UID, are provided as
+ wildcards for the bus ID and UID, respectively.
+ When a match is found, the PHY layer will invoke the run function associated
+ with the fixup. This function is passed a pointer to the phy_device of
+ interest. It should therefore only operate on that PHY.
+ The platform code can either register the fixup using phy_register_fixup():
+ int phy_register_fixup(const char *phy_id,
+ u32 phy_uid, u32 phy_uid_mask,
+ int (*run)(struct phy_device *));
+ Or using one of the two stubs, phy_register_fixup_for_uid() and
+ phy_register_fixup_for_id():
+ int phy_register_fixup_for_uid(u32 phy_uid, u32 phy_uid_mask,
+ int (*run)(struct phy_device *));
+ int phy_register_fixup_for_id(const char *phy_id,
+ int (*run)(struct phy_device *));
+ The stubs set one of the two matching criteria, and set the other one to
+ match anything.