net: phy: micrel: ksz886x/ksz8081: add cabletest support

This patch support for cable test for the ksz886x switches and the
ksz8081 PHY.

The patch was tested on a KSZ8873RLL switch with following results:

- port 1:
  - provides invalid values, thus return -ENOTSUPP
    (Errata: DS80000830A: "LinkMD does not work on Port 1",
     http://ww1.microchip.com/downloads/en/DeviceDoc/KSZ8873-Errata-DS80000830A.pdf)

- port 2:
  - can detect distance
  - can detect open on each wire of pair A (wire 1 and 2)
  - can detect open only on one wire of pair B (only wire 3)
  - can detect short between wires of a pair (wires 1 + 2 or 3 + 6)
  - short between pairs is detected as open.
    For example short between wires 2 + 3 is detected as open.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Oleksij Rempel 2021-06-14 06:31:25 +02:00 committed by David S. Miller
parent c916e8e1ea
commit 49011e0c15
3 changed files with 194 additions and 0 deletions

View file

@ -39,6 +39,7 @@
/* struct phy_device dev_flags definitions */
#define MICREL_PHY_50MHZ_CLK 0x00000001
#define MICREL_PHY_FXEN 0x00000002
#define MICREL_KSZ8_P1_ERRATA 0x00000003
#define MICREL_KSZ9021_EXTREG_CTRL 0xB
#define MICREL_KSZ9021_EXTREG_DATA_WRITE 0xC