phy: add the EEE support and the way to access to the MMD registers.

This patch adds the support for the Energy-Efficient Ethernet (EEE)
to the Physical Abstraction Layer.
To support the EEE we have to access to the MMD registers 3.20 and
7.60/61. So two new functions have been added to read/write the MMD
registers (clause 45).

An Ethernet driver (I tested the stmmac) can invoke the phy_init_eee to properly
check if the EEE is supported by the PHYs and it can also set the clock
stop enable bit in the 3.0 register.
The phy_get_eee_err can be used for reporting the number of time where
the PHY failed to complete its normal wake sequence.

In the end, this patch also adds the EEE ethtool support implementing:
 o phy_ethtool_set_eee
 o phy_ethtool_get_eee

v1: initial patch
v2: fixed some errors especially on naming convention
v3: renamed again the mmd read/write functions thank to Ben's feedback
v4: moved file to phy.c and added the ethtool support.
v5: fixed phy_adv_to_eee, phy_eee_to_supported, phy_eee_to_adv return
    values according to ethtool API (thanks to Ben's feedback).
    Renamed some macros to avoid too long names.
v6: fixed kernel-doc comments to be properly parsed.
    Fixed the phy_init_eee function: we need to check which link mode
    was autonegotiated and then the corresponding bits in 7.60 and 7.61
    registers.
v7: reviewed the way to get the negotiated settings.
v8: fixed a problem in the phy_init_eee return value erroneously added
    when included the phy_read_status call.
v9: do not remove the MDIO_AN_EEE_ADV_100TX and MDIO_AN_EEE_ADV_1000T
    and fixed the eee_{cap,lp,adv} declaration as "int" instead of u16.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/mii.h b/include/linux/mii.h
index 2783eca629a0..8ef3a7a11592 100644
--- a/include/linux/mii.h
+++ b/include/linux/mii.h
@@ -21,6 +21,8 @@
 #define MII_EXPANSION		0x06	/* Expansion register          */
 #define MII_CTRL1000		0x09	/* 1000BASE-T control          */
 #define MII_STAT1000		0x0a	/* 1000BASE-T status           */
+#define	MII_MMD_CTRL		0x0d	/* MMD Access Control Register */
+#define	MII_MMD_DATA		0x0e	/* MMD Access Data Register */
 #define MII_ESTATUS		0x0f	/* Extended Status             */
 #define MII_DCOUNTER		0x12	/* Disconnect counter          */
 #define MII_FCSCOUNTER		0x13	/* False carrier counter       */
@@ -141,6 +143,13 @@
 #define FLOW_CTRL_TX		0x01
 #define FLOW_CTRL_RX		0x02
 
+/* MMD Access Control register fields */
+#define MII_MMD_CTRL_DEVAD_MASK	0x1f	/* Mask MMD DEVAD*/
+#define MII_MMD_CTRL_ADDR	0x0000	/* Address */
+#define MII_MMD_CTRL_NOINCR	0x4000	/* no post increment */
+#define MII_MMD_CTRL_INCR_RDWT	0x8000	/* post increment on reads & writes */
+#define MII_MMD_CTRL_INCR_ON_WT	0xC000	/* post increment on writes only */
+
 /* This structure is used in all SIOCxMIIxxx ioctl calls */
 struct mii_ioctl_data {
 	__u16		phy_id;