usb: chipidea: add workaround for chipidea PEC bug

Some NXP processors using ChipIdea USB IP have a bug when frame babble is
detected.

Issue description:
In USB camera test, our controller is host in HS mode. In ISOC IN, when
device sends data across the micro frame, it causes the babble in host
controller. This will clear the PE bit. In spec, it also requires to set
the PEC bit and then set the PCI bit. Without the PCI interrupt, the
software does not know the PE is cleared.

This will add a flag CI_HDRC_HAS_PORTSC_PEC_MISSED to some impacted
platform datas. And the ehci host driver will assert PEC by SW when
specific conditions are satisfied.

Signed-off-by: Xu Yang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Xu Yang

drivers/usb/chipidea/ci.h

@@ -257,6 +257,7 @@ struct ci_hdrc {
 	bool				id_event;
 	bool				b_sess_valid_event;
 	bool				imx28_write_fix;
+	bool				has_portsc_pec_bug;
 	bool				supports_runtime_pm;
 	bool				in_lpm;
 	bool				wakeup_int;

drivers/usb/chipidea/ci_hdrc_imx.c

@@ -68,11 +68,13 @@ static const struct ci_hdrc_imx_platform_flag imx7d_usb_data = {
 
 static const struct ci_hdrc_imx_platform_flag imx7ulp_usb_data = {
 	.flags = CI_HDRC_SUPPORTS_RUNTIME_PM |
+		CI_HDRC_HAS_PORTSC_PEC_MISSED |
 		CI_HDRC_PMQOS,
 };
 
 static const struct ci_hdrc_imx_platform_flag imx8ulp_usb_data = {
-	.flags = CI_HDRC_SUPPORTS_RUNTIME_PM,
+	.flags = CI_HDRC_SUPPORTS_RUNTIME_PM |
+		CI_HDRC_HAS_PORTSC_PEC_MISSED,
 };
 
 static const struct of_device_id ci_hdrc_imx_dt_ids[] = {

drivers/usb/chipidea/core.c

@@ -1044,6 +1044,8 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 		CI_HDRC_IMX28_WRITE_FIX);
 	ci->supports_runtime_pm = !!(ci->platdata->flags &
 		CI_HDRC_SUPPORTS_RUNTIME_PM);
+	ci->has_portsc_pec_bug = !!(ci->platdata->flags &
+		CI_HDRC_HAS_PORTSC_PEC_MISSED);
 	platform_set_drvdata(pdev, ci);
 
 	ret = hw_device_init(ci, base);

drivers/usb/chipidea/host.c

@@ -151,6 +151,7 @@ static int host_start(struct ci_hdrc *ci)
 	ehci->has_hostpc = ci->hw_bank.lpm;
 	ehci->has_tdi_phy_lpm = ci->hw_bank.lpm;
 	ehci->imx28_write_fix = ci->imx28_write_fix;
+	ehci->has_ci_pec_bug = ci->has_portsc_pec_bug;
 
 	priv = (struct ehci_ci_priv *)ehci->priv;
 	priv->reg_vbus = NULL;

include/linux/usb/chipidea.h

@@ -63,6 +63,7 @@ struct ci_hdrc_platform_data {
 #define CI_HDRC_IMX_IS_HSIC		BIT(14)
 #define CI_HDRC_PMQOS			BIT(15)
 #define CI_HDRC_PHY_VBUS_CONTROL	BIT(16)
+#define CI_HDRC_HAS_PORTSC_PEC_MISSED	BIT(17)
 	enum usb_dr_mode	dr_mode;
 #define CI_HDRC_CONTROLLER_RESET_EVENT		0
 #define CI_HDRC_CONTROLLER_STOPPED_EVENT	1