diff mbox series

[v2,2/2] phy: qcom-usb-hs: Add qcom,dp-manual-pullup logic

Message ID 20221229183410.683584-3-bryan.odonoghue@linaro.org
State New
Headers show
Series qcom: Add a method to manually toggle the DP pullup on HS USB PHY | expand

Commit Message

Bryan O'Donoghue Dec. 29, 2022, 6:34 p.m. UTC 
Downstream has a flag called qcom,dp-manual-pullup which informs the
downstream driver if it should toggle ULPI_MISC_A_VBUSVLDEXTSEL and
ULPI_MISC_A_VBUSVLDEXT.

Downstream states:

"qcom,dp-manual-pullup: If present, vbus is not routed to USB
        controller/phy and controller driver therefore enables pull-up
        explicitly before starting controller using usbcmd run/stop bit."

Working with a system that has both an external Type-C port controller and
an internal USB Hub results in a situation where VBUS is not connected to
the SoC.

In this case we still need to set the DP pullup.

This patch enables and disables the DP pullup on PHY power_on and power_off
respectively if the DT has declared the bool "qcom,enable-vbus-pullup"
effectively replicating the downstream logic to the same effect.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
---
 drivers/phy/qualcomm/phy-qcom-usb-hs.c | 36 ++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

Comments

Stephan Gerhold Dec. 30, 2022, 12:05 p.m. UTC | #1 
On Thu, Dec 29, 2022 at 11:38:04PM +0000, Bryan O'Donoghue wrote:
> On 29/12/2022 21:41, Stephan Gerhold wrote:
> > That is still good enough to replace qcom,dp-manual-pullup though.
> 
> But there's no requirement to tie USB_IN_x high if VBUS is not connected to
> it.
> 

I've yet to find any device where USB_IN is not connected in a usable way.

But as I said I leave it up to you - it would be nice to have a proper
solution for devices where VBUS state cannot be determined at all. Those
devices should be rare though so if &pm8916_usbin works in your case
maybe the time would be better invested into other open problems right
now. :)

Thanks,
Stephan
diff mbox series

Patch

diff --git a/drivers/phy/qualcomm/phy-qcom-usb-hs.c b/drivers/phy/qualcomm/phy-qcom-usb-hs.c
index 53e46c220a3aa..45c94f6722c66 100644
--- a/drivers/phy/qualcomm/phy-qcom-usb-hs.c
+++ b/drivers/phy/qualcomm/phy-qcom-usb-hs.c
@@ -37,6 +37,7 @@  struct qcom_usb_hs_phy {
 	struct ulpi_seq *init_seq;
 	struct extcon_dev *vbus_edev;
 	struct notifier_block vbus_notify;
+	u8 enable_dp_pullup:1;
 };
 
 static int qcom_usb_hs_phy_set_mode(struct phy *phy,
@@ -105,6 +106,23 @@  qcom_usb_hs_phy_vbus_notifier(struct notifier_block *nb, unsigned long event,
 	return ulpi_write(uphy->ulpi, addr, ULPI_MISC_A_VBUSVLDEXT);
 }
 
+static int qcom_usb_hs_phy_enable_dp_pullup(struct ulpi *ulpi, bool enable)
+{
+	u8 addr;
+	int ret;
+
+	if (enable)
+		addr = ULPI_SET(ULPI_MISC_A);
+	else
+		addr = ULPI_CLR(ULPI_MISC_A);
+
+	ret = ulpi_write(ulpi, addr, ULPI_MISC_A_VBUSVLDEXTSEL);
+	if (ret)
+		return ret;
+
+	return ulpi_write(ulpi, addr, ULPI_MISC_A_VBUSVLDEXT);
+}
+
 static int qcom_usb_hs_phy_power_on(struct phy *phy)
 {
 	struct qcom_usb_hs_phy *uphy = phy_get_drvdata(phy);
@@ -154,6 +172,12 @@  static int qcom_usb_hs_phy_power_on(struct phy *phy)
 			goto err_ulpi;
 	}
 
+	if (uphy->enable_dp_pullup) {
+		ret = qcom_usb_hs_phy_enable_dp_pullup(ulpi, true);
+		if (ret)
+			goto err_ulpi;
+	}
+
 	if (uphy->vbus_edev) {
 		state = extcon_get_state(uphy->vbus_edev, EXTCON_USB);
 		/* setup initial state */
@@ -180,10 +204,19 @@  static int qcom_usb_hs_phy_power_on(struct phy *phy)
 static int qcom_usb_hs_phy_power_off(struct phy *phy)
 {
 	struct qcom_usb_hs_phy *uphy = phy_get_drvdata(phy);
+	struct ulpi *ulpi = uphy->ulpi;
+	int ret;
 
 	if (uphy->vbus_edev)
 		extcon_unregister_notifier(uphy->vbus_edev, EXTCON_USB,
 					   &uphy->vbus_notify);
+
+	if (uphy->enable_dp_pullup) {
+		ret = qcom_usb_hs_phy_enable_dp_pullup(ulpi, false);
+		if (ret)
+			return ret;
+	}
+
 	regulator_disable(uphy->v3p3);
 	regulator_disable(uphy->v1p8);
 	clk_disable_unprepare(uphy->sleep_clk);
@@ -229,6 +262,9 @@  static int qcom_usb_hs_phy_probe(struct ulpi *ulpi)
 	/* NUL terminate */
 	uphy->init_seq[size / 2].addr = uphy->init_seq[size / 2].val = 0;
 
+	if (of_property_read_bool(ulpi->dev.of_node, "qcom,dp-manual-pullup"))
+		uphy->enable_dp_pullup = 1;
+
 	uphy->ref_clk = clk = devm_clk_get(&ulpi->dev, "ref");
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);