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

Andre Przywara
2021-06-15T11:07:33Z

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;
+ }
+
+ /*
+ * This extra clock is just needed to access the
+ * REG_HCI_PHY_CTL PMU register for PHY2.
+ */
+ ret = clk_prepare_enable(phy2->clk2);
+ if (ret) {
+ reset_control_assert(phy2->reset);
+ clk_disable_unprepare(phy2->clk);
+ reset_control_assert(phy->reset);
+ clk_disable_unprepare(phy->clk2);
+ clk_disable_unprepare(phy->clk);
+ return ret;
+ }
+
+ if (phy2->pmu && data->cfg->hci_phy_ctl_clear) {
+ val = readl(phy2->pmu + REG_HCI_PHY_CTL);
+ val &= ~data->cfg->hci_phy_ctl_clear;
+ writel(val, phy2->pmu + REG_HCI_PHY_CTL);
+ }
+
+ clk_disable_unprepare(phy->clk2);
+ }
+
if (phy->pmu && data->cfg->hci_phy_ctl_clear) {
val = readl(phy->pmu + REG_HCI_PHY_CTL);
val &= ~data->cfg->hci_phy_ctl_clear;
@@ -354,6 +399,13 @@ static int sun4i_usb_phy_exit(struct phy *_phy)
data->phy0_init = false;
}

+ if (data->cfg->needs_phy2_siddq && phy->index != 2) {
+ struct sun4i_usb_phy *phy2 = &data->phys[2];
+
+ clk_disable_unprepare(phy2->clk);
+ reset_control_assert(phy2->reset);
+ }
+
sun4i_usb_phy_passby(phy, 0);
reset_control_assert(phy->reset);
clk_disable_unprepare(phy->clk2);
@@ -785,6 +837,13 @@ static int sun4i_usb_phy_probe(struct platform_device *pdev)
dev_err(dev, "failed to get clock %s\n", name);
return PTR_ERR(phy->clk2);
}
+ } else {
+ snprintf(name, sizeof(name), "pmu%d_clk", i);
+ phy->clk2 = devm_clk_get_optional(dev, name);
+ if (IS_ERR(phy->clk2)) {
+ dev_err(dev, "failed to get clock %s\n", name);
+ return PTR_ERR(phy->clk2);
+ }
}

snprintf(name, sizeof(name), "usb%d_reset", i);
--
2.17.5