Re: [PATCH v7 14/19] phy: sun4i-usb: Introduce port2 SIDDQ quirk

At least the Allwinner H616 SoC requires a weird quirk to make most
USB PHYs work: Only port2 works out of the box, but all other ports
need some help from this port2 to work correctly: The CLK_BUS_PHY2 and
RST_USB_PHY2 clock and reset need to be enabled, and the SIDDQ bit in
the PMU PHY control register needs to be cleared. For this register to
be accessible, CLK_BUS_ECHI2 needs to be ungated. Don't ask ....

Instead of disguising this as some generic feature, do exactly that
in our PHY init:
If the quirk bit is set, and we initialise a PHY other than PHY2, ungate
this one special clock, and clear the SIDDQ bit. We can pull in the
other required clocks via the DT.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 drivers/phy/allwinner/phy-sun4i-usb.c | 59 +++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c
index 126ef74d013c..316ef5fca831 100644
--- a/drivers/phy/allwinner/phy-sun4i-usb.c
+++ b/drivers/phy/allwinner/phy-sun4i-usb.c

@@ -120,6 +120,7 @@ struct sun4i_usb_phy_cfg {
 	u8 phyctl_offset;
 	bool dedicated_clocks;
 	bool phy0_dual_route;
+	bool needs_phy2_siddq;
 	int missing_phys;
 };
 

@@ -289,6 +290,50 @@ static int sun4i_usb_phy_init(struct phy *_phy)
 		return ret;
 	}
 
+	/* Some PHYs on some SoCs need the help of PHY2 to work. */
+	if (data->cfg->needs_phy2_siddq && phy->index != 2) {
+		struct sun4i_usb_phy *phy2 = &data->phys[2];
+
+		ret = clk_prepare_enable(phy2->clk);
+		if (ret) {
+			reset_control_assert(phy->reset);
+			clk_disable_unprepare(phy->clk2);
+			clk_disable_unprepare(phy->clk);
+			return ret;
+		}
+
+		ret = reset_control_deassert(phy2->reset);
+		if (ret) {
+			clk_disable_unprepare(phy2->clk);
+			reset_control_assert(phy->reset);
+			clk_disable_unprepare(phy->clk2);
+			clk_disable_unprepare(phy->clk);
+			return ret;
+		}