[PATCH net-next v2] net: phy: broadcom: Enable 10BaseT DAC early wake

From: Florian Fainelli
Date: Thu Sep 16 2021 - 17:28:09 EST


Enable the DAC early wake when then link operates at 10BaseT allows
power savings in the hundreds of milli Watts by shutting down the
transmitter. A number of errata have been issued for various Gigabit
PHYs and the recommendation is to enable both the early and forced DAC
wake to be on the safe side. This needs to be done dynamically based
upon the link state, which is why a link_change_notify callback is
utilized.

Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
Changes in v2:

- fixed checkpath warning on the return statuement in the
link_change_notify callback

drivers/net/phy/broadcom.c | 47 ++++++++++++++++++++++++++++++++++++++
include/linux/brcmphy.h | 1 +
2 files changed, 48 insertions(+)

diff --git a/drivers/net/phy/broadcom.c b/drivers/net/phy/broadcom.c
index 83aea5c5cd03..add0c4e33425 100644
--- a/drivers/net/phy/broadcom.c
+++ b/drivers/net/phy/broadcom.c
@@ -702,6 +702,36 @@ static void bcm54xx_get_stats(struct phy_device *phydev,
bcm_phy_get_stats(phydev, priv->stats, stats, data);
}

+static void bcm54xx_link_change_notify(struct phy_device *phydev)
+{
+ u16 mask = MII_BCM54XX_EXP_EXP08_EARLY_DAC_WAKE |
+ MII_BCM54XX_EXP_EXP08_FORCE_DAC_WAKE;
+ int ret;
+
+ if (phydev->state != PHY_RUNNING)
+ return;
+
+ /* Don't change the DAC wake settings if auto power down
+ * is not requested.
+ */
+ if (!(phydev->dev_flags & PHY_BRCM_AUTO_PWRDWN_ENABLE))
+ return;
+
+ ret = bcm_phy_read_exp(phydev, MII_BCM54XX_EXP_EXP08);
+ if (ret < 0)
+ return;
+
+ /* Enable/disable 10BaseT auto and forced early DAC wake depending
+ * on the negotiated speed, those settings should only be done
+ * for 10Mbits/sec.
+ */
+ if (phydev->speed == SPEED_10)
+ ret |= mask;
+ else
+ ret &= ~mask;
+ bcm_phy_write_exp(phydev, MII_BCM54XX_EXP_EXP08, ret);
+}
+
static struct phy_driver broadcom_drivers[] = {
{
.phy_id = PHY_ID_BCM5411,
@@ -715,6 +745,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_init = bcm54xx_config_init,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM5421,
.phy_id_mask = 0xfffffff0,
@@ -727,6 +758,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_init = bcm54xx_config_init,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM54210E,
.phy_id_mask = 0xfffffff0,
@@ -739,6 +771,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_init = bcm54xx_config_init,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM5461,
.phy_id_mask = 0xfffffff0,
@@ -751,6 +784,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_init = bcm54xx_config_init,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM54612E,
.phy_id_mask = 0xfffffff0,
@@ -763,6 +797,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_init = bcm54xx_config_init,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM54616S,
.phy_id_mask = 0xfffffff0,
@@ -774,6 +809,7 @@ static struct phy_driver broadcom_drivers[] = {
.handle_interrupt = bcm_phy_handle_interrupt,
.read_status = bcm54616s_read_status,
.probe = bcm54616s_probe,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM5464,
.phy_id_mask = 0xfffffff0,
@@ -788,6 +824,7 @@ static struct phy_driver broadcom_drivers[] = {
.handle_interrupt = bcm_phy_handle_interrupt,
.suspend = genphy_suspend,
.resume = genphy_resume,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM5481,
.phy_id_mask = 0xfffffff0,
@@ -801,6 +838,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_aneg = bcm5481_config_aneg,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM54810,
.phy_id_mask = 0xfffffff0,
@@ -816,6 +854,7 @@ static struct phy_driver broadcom_drivers[] = {
.handle_interrupt = bcm_phy_handle_interrupt,
.suspend = genphy_suspend,
.resume = bcm54xx_resume,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM54811,
.phy_id_mask = 0xfffffff0,
@@ -831,6 +870,7 @@ static struct phy_driver broadcom_drivers[] = {
.handle_interrupt = bcm_phy_handle_interrupt,
.suspend = genphy_suspend,
.resume = bcm54xx_resume,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM5482,
.phy_id_mask = 0xfffffff0,
@@ -843,6 +883,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_init = bcm54xx_config_init,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM50610,
.phy_id_mask = 0xfffffff0,
@@ -855,6 +896,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_init = bcm54xx_config_init,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM50610M,
.phy_id_mask = 0xfffffff0,
@@ -867,6 +909,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_init = bcm54xx_config_init,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM57780,
.phy_id_mask = 0xfffffff0,
@@ -879,6 +922,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_init = bcm54xx_config_init,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCMAC131,
.phy_id_mask = 0xfffffff0,
@@ -905,6 +949,7 @@ static struct phy_driver broadcom_drivers[] = {
.get_strings = bcm_phy_get_strings,
.get_stats = bcm54xx_get_stats,
.probe = bcm54xx_phy_probe,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM53125,
.phy_id_mask = 0xfffffff0,
@@ -918,6 +963,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_init = bcm54xx_config_init,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
}, {
.phy_id = PHY_ID_BCM89610,
.phy_id_mask = 0xfffffff0,
@@ -930,6 +976,7 @@ static struct phy_driver broadcom_drivers[] = {
.config_init = bcm54xx_config_init,
.config_intr = bcm_phy_config_intr,
.handle_interrupt = bcm_phy_handle_interrupt,
+ .link_change_notify = bcm54xx_link_change_notify,
} };

module_phy_driver(broadcom_drivers);
diff --git a/include/linux/brcmphy.h b/include/linux/brcmphy.h
index c2c2147dfeb8..3308cebe1c19 100644
--- a/include/linux/brcmphy.h
+++ b/include/linux/brcmphy.h
@@ -233,6 +233,7 @@
#define MII_BCM54XX_EXP_EXP08 0x0F08
#define MII_BCM54XX_EXP_EXP08_RJCT_2MHZ 0x0001
#define MII_BCM54XX_EXP_EXP08_EARLY_DAC_WAKE 0x0200
+#define MII_BCM54XX_EXP_EXP08_FORCE_DAC_WAKE 0x0100
#define MII_BCM54XX_EXP_EXP75 0x0f75
#define MII_BCM54XX_EXP_EXP75_VDACCTRL 0x003c
#define MII_BCM54XX_EXP_EXP75_CM_OSC 0x0001
--
2.25.1