--- /dev/null
+From d88fd1b546ff19c8040cfaea76bf16aed1c5a0bb Mon Sep 17 00:00:00 2001
+From: Florian Fainelli <f.fainelli@gmail.com>
+Date: Tue, 28 Sep 2021 13:32:33 -0700
+Subject: net: phy: bcm7xxx: Fixed indirect MMD operations
+
+From: Florian Fainelli <f.fainelli@gmail.com>
+
+commit d88fd1b546ff19c8040cfaea76bf16aed1c5a0bb upstream.
+
+When EEE support was added to the 28nm EPHY it was assumed that it would
+be able to support the standard clause 45 over clause 22 register access
+method. It turns out that the PHY does not support that, which is the
+very reason for using the indirect shadow mode 2 bank 3 access method.
+
+Implement {read,write}_mmd to allow the standard PHY library routines
+pertaining to EEE querying and configuration to work correctly on these
+PHYs. This forces us to implement a __phy_set_clr_bits() function that
+does not grab the MDIO bus lock since the PHY driver's {read,write}_mmd
+functions are always called with that lock held.
+
+Fixes: 83ee102a6998 ("net: phy: bcm7xxx: add support for 28nm EPHY")
+[florian: adjust locking since phy_{read,write}_mmd are called with no
+PHYLIB locks held]
+Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/net/phy/bcm7xxx.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 94 insertions(+)
+
+--- a/drivers/net/phy/bcm7xxx.c
++++ b/drivers/net/phy/bcm7xxx.c
+@@ -30,7 +30,12 @@
+ #define MII_BCM7XXX_SHD_2_ADDR_CTRL 0xe
+ #define MII_BCM7XXX_SHD_2_CTRL_STAT 0xf
+ #define MII_BCM7XXX_SHD_2_BIAS_TRIM 0x1a
++#define MII_BCM7XXX_SHD_3_PCS_CTRL 0x0
++#define MII_BCM7XXX_SHD_3_PCS_STATUS 0x1
++#define MII_BCM7XXX_SHD_3_EEE_CAP 0x2
+ #define MII_BCM7XXX_SHD_3_AN_EEE_ADV 0x3
++#define MII_BCM7XXX_SHD_3_EEE_LP 0x4
++#define MII_BCM7XXX_SHD_3_EEE_WK_ERR 0x5
+ #define MII_BCM7XXX_SHD_3_PCS_CTRL_2 0x6
+ #define MII_BCM7XXX_PCS_CTRL_2_DEF 0x4400
+ #define MII_BCM7XXX_SHD_3_AN_STAT 0xb
+@@ -462,6 +467,93 @@ static int bcm7xxx_28nm_ephy_config_init
+ return bcm7xxx_28nm_ephy_apd_enable(phydev);
+ }
+
++#define MII_BCM7XXX_REG_INVALID 0xff
++
++static u8 bcm7xxx_28nm_ephy_regnum_to_shd(u16 regnum)
++{
++ switch (regnum) {
++ case MDIO_CTRL1:
++ return MII_BCM7XXX_SHD_3_PCS_CTRL;
++ case MDIO_STAT1:
++ return MII_BCM7XXX_SHD_3_PCS_STATUS;
++ case MDIO_PCS_EEE_ABLE:
++ return MII_BCM7XXX_SHD_3_EEE_CAP;
++ case MDIO_AN_EEE_ADV:
++ return MII_BCM7XXX_SHD_3_AN_EEE_ADV;
++ case MDIO_AN_EEE_LPABLE:
++ return MII_BCM7XXX_SHD_3_EEE_LP;
++ case MDIO_PCS_EEE_WK_ERR:
++ return MII_BCM7XXX_SHD_3_EEE_WK_ERR;
++ default:
++ return MII_BCM7XXX_REG_INVALID;
++ }
++}
++
++static bool bcm7xxx_28nm_ephy_dev_valid(int devnum)
++{
++ return devnum == MDIO_MMD_AN || devnum == MDIO_MMD_PCS;
++}
++
++static int bcm7xxx_28nm_ephy_read_mmd(struct phy_device *phydev,
++ int devnum, u16 regnum)
++{
++ u8 shd = bcm7xxx_28nm_ephy_regnum_to_shd(regnum);
++ int ret;
++
++ if (!bcm7xxx_28nm_ephy_dev_valid(devnum) ||
++ shd == MII_BCM7XXX_REG_INVALID)
++ return -EOPNOTSUPP;
++
++ /* set shadow mode 2 */
++ ret = phy_set_clr_bits(phydev, MII_BCM7XXX_TEST,
++ MII_BCM7XXX_SHD_MODE_2, 0);
++ if (ret < 0)
++ return ret;
++
++ /* Access the desired shadow register address */
++ ret = phy_write(phydev, MII_BCM7XXX_SHD_2_ADDR_CTRL, shd);
++ if (ret < 0)
++ goto reset_shadow_mode;
++
++ ret = phy_read(phydev, MII_BCM7XXX_SHD_2_CTRL_STAT);
++
++reset_shadow_mode:
++ /* reset shadow mode 2 */
++ phy_set_clr_bits(phydev, MII_BCM7XXX_TEST, 0,
++ MII_BCM7XXX_SHD_MODE_2);
++ return ret;
++}
++
++static int bcm7xxx_28nm_ephy_write_mmd(struct phy_device *phydev,
++ int devnum, u16 regnum, u16 val)
++{
++ u8 shd = bcm7xxx_28nm_ephy_regnum_to_shd(regnum);
++ int ret;
++
++ if (!bcm7xxx_28nm_ephy_dev_valid(devnum) ||
++ shd == MII_BCM7XXX_REG_INVALID)
++ return -EOPNOTSUPP;
++
++ /* set shadow mode 2 */
++ ret = phy_set_clr_bits(phydev, MII_BCM7XXX_TEST,
++ MII_BCM7XXX_SHD_MODE_2, 0);
++ if (ret < 0)
++ return ret;
++
++ /* Access the desired shadow register address */
++ ret = phy_write(phydev, MII_BCM7XXX_SHD_2_ADDR_CTRL, shd);
++ if (ret < 0)
++ goto reset_shadow_mode;
++
++ /* Write the desired value in the shadow register */
++ phy_write(phydev, MII_BCM7XXX_SHD_2_CTRL_STAT, val);
++
++reset_shadow_mode:
++ /* reset shadow mode 2 */
++ return phy_set_clr_bits(phydev, MII_BCM7XXX_TEST, 0,
++ MII_BCM7XXX_SHD_MODE_2);
++}
++
+ static int bcm7xxx_28nm_ephy_resume(struct phy_device *phydev)
+ {
+ int ret;
+@@ -637,6 +729,8 @@ static int bcm7xxx_28nm_probe(struct phy
+ .get_strings = bcm_phy_get_strings, \
+ .get_stats = bcm7xxx_28nm_get_phy_stats, \
+ .probe = bcm7xxx_28nm_probe, \
++ .read_mmd = bcm7xxx_28nm_ephy_read_mmd, \
++ .write_mmd = bcm7xxx_28nm_ephy_write_mmd, \
+ }
+
+ #define BCM7XXX_40NM_EPHY(_oui, _name) \
projects / thirdparty / kernel / stable-queue.git / commitdiff
