From: Jerome Brunet <jbrunet@xxxxxxxxxxxx> [ Upstream commit 7083df59abbc2b7500db312cac706493be0273ff ] Force the internal PHY off then on when switching to the internal path. This fixes problems where the PHY ID is not properly set. Fixes: 7090425104db ("net: phy: add amlogic g12a mdio mux support") Suggested-by: Qi Duan <qi.duan@xxxxxxxxxxx> Co-developed-by: Heiner Kallweit <hkallweit1@xxxxxxxxx> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx> Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230124101157.232234-1-jbrunet@xxxxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/mdio/mdio-mux-meson-g12a.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/net/mdio/mdio-mux-meson-g12a.c b/drivers/net/mdio/mdio-mux-meson-g12a.c index 4a2e94faf57e..c4542ecf5623 100644 --- a/drivers/net/mdio/mdio-mux-meson-g12a.c +++ b/drivers/net/mdio/mdio-mux-meson-g12a.c @@ -4,6 +4,7 @@ */ #include <linux/bitfield.h> +#include <linux/delay.h> #include <linux/clk.h> #include <linux/clk-provider.h> #include <linux/device.h> @@ -150,6 +151,7 @@ static const struct clk_ops g12a_ephy_pll_ops = { static int g12a_enable_internal_mdio(struct g12a_mdio_mux *priv) { + u32 value; int ret; /* Enable the phy clock */ @@ -163,18 +165,25 @@ static int g12a_enable_internal_mdio(struct g12a_mdio_mux *priv) /* Initialize ephy control */ writel(EPHY_G12A_ID, priv->regs + ETH_PHY_CNTL0); - writel(FIELD_PREP(PHY_CNTL1_ST_MODE, 3) | - FIELD_PREP(PHY_CNTL1_ST_PHYADD, EPHY_DFLT_ADD) | - FIELD_PREP(PHY_CNTL1_MII_MODE, EPHY_MODE_RMII) | - PHY_CNTL1_CLK_EN | - PHY_CNTL1_CLKFREQ | - PHY_CNTL1_PHY_ENB, - priv->regs + ETH_PHY_CNTL1); + + /* Make sure we get a 0 -> 1 transition on the enable bit */ + value = FIELD_PREP(PHY_CNTL1_ST_MODE, 3) | + FIELD_PREP(PHY_CNTL1_ST_PHYADD, EPHY_DFLT_ADD) | + FIELD_PREP(PHY_CNTL1_MII_MODE, EPHY_MODE_RMII) | + PHY_CNTL1_CLK_EN | + PHY_CNTL1_CLKFREQ; + writel(value, priv->regs + ETH_PHY_CNTL1); writel(PHY_CNTL2_USE_INTERNAL | PHY_CNTL2_SMI_SRC_MAC | PHY_CNTL2_RX_CLK_EPHY, priv->regs + ETH_PHY_CNTL2); + value |= PHY_CNTL1_PHY_ENB; + writel(value, priv->regs + ETH_PHY_CNTL1); + + /* The phy needs a bit of time to power up */ + mdelay(10); + return 0; } -- 2.39.0