[PATCH 1/3] usb: dwc2: override PHY input signals with usb role switch support
From: Amelie Delaunay
Date: Tue Jun 16 2020 - 10:07:51 EST
This patch adds support for usb role switch to dwc2, by using overriding
control of the PHY voltage valid and ID input signals.
iddig signal (ID) can be overridden:
- when setting GUSBCFG_FORCEHOSTMODE, iddig input pin is overridden with 1;
- when setting GUSBCFG_FORCEDEVMODE, iddig input pin is overridden with 0.
avalid/bvalid/vbusvalid signals can be overridden respectively with:
- GOTGCTL_AVALOEN + GOTGCTL_AVALOVAL
- GOTGCTL_BVALOEN + GOTGCTL_BVALOVAL
- GOTGCTL_VBVALEN + GOTGCTL_VBVALOVAL
It is possible to determine valid sessions thanks to usb role switch:
- if USB_ROLE_NONE then !avalid && !bvalid && !vbusvalid
- if USB_ROLE_DEVICE then !avalid && bvalid && vbusvalid
- if USB_ROLE_HOST then avalid && !bvalid && vbusvalid
Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxx>
---
drivers/usb/dwc2/Kconfig | 1 +
drivers/usb/dwc2/Makefile | 2 +-
drivers/usb/dwc2/core.h | 8 ++
drivers/usb/dwc2/drd.c | 190 ++++++++++++++++++++++++++++++++++++
drivers/usb/dwc2/gadget.c | 2 +-
drivers/usb/dwc2/platform.c | 13 +++
6 files changed, 214 insertions(+), 2 deletions(-)
create mode 100644 drivers/usb/dwc2/drd.c
diff --git a/drivers/usb/dwc2/Kconfig b/drivers/usb/dwc2/Kconfig
index 16e1aa304edc..dceb8f32414e 100644
--- a/drivers/usb/dwc2/Kconfig
+++ b/drivers/usb/dwc2/Kconfig
@@ -47,6 +47,7 @@ config USB_DWC2_PERIPHERAL
config USB_DWC2_DUAL_ROLE
bool "Dual Role mode"
depends on (USB=y && USB_GADGET=y) || (USB_DWC2=m && USB && USB_GADGET)
+ select USB_ROLE_SWITCH
help
Select this option if you want the driver to work in a dual-role
mode. In this mode both host and gadget features are enabled, and
diff --git a/drivers/usb/dwc2/Makefile b/drivers/usb/dwc2/Makefile
index 440320cc20a4..2bcd6945df46 100644
--- a/drivers/usb/dwc2/Makefile
+++ b/drivers/usb/dwc2/Makefile
@@ -3,7 +3,7 @@ ccflags-$(CONFIG_USB_DWC2_DEBUG) += -DDEBUG
ccflags-$(CONFIG_USB_DWC2_VERBOSE) += -DVERBOSE_DEBUG
obj-$(CONFIG_USB_DWC2) += dwc2.o
-dwc2-y := core.o core_intr.o platform.o
+dwc2-y := core.o core_intr.o platform.o drd.o
dwc2-y += params.o
ifneq ($(filter y,$(CONFIG_USB_DWC2_HOST) $(CONFIG_USB_DWC2_DUAL_ROLE)),)
diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index 132d687f1590..9f529e27eaaa 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -860,6 +860,7 @@ struct dwc2_hregs_backup {
* - USB_DR_MODE_PERIPHERAL
* - USB_DR_MODE_HOST
* - USB_DR_MODE_OTG
+ * @role_sw: usb_role_switch handle
* @hcd_enabled: Host mode sub-driver initialization indicator.
* @gadget_enabled: Peripheral mode sub-driver initialization indicator.
* @ll_hw_enabled: Status of low-level hardware resources.
@@ -1054,6 +1055,7 @@ struct dwc2_hsotg {
struct dwc2_core_params params;
enum usb_otg_state op_state;
enum usb_dr_mode dr_mode;
+ struct usb_role_switch *role_sw;
unsigned int hcd_enabled:1;
unsigned int gadget_enabled:1;
unsigned int ll_hw_enabled:1;
@@ -1376,6 +1378,11 @@ static inline int dwc2_is_device_mode(struct dwc2_hsotg *hsotg)
return (dwc2_readl(hsotg, GINTSTS) & GINTSTS_CURMODE_HOST) == 0;
}
+int dwc2_drd_init(struct dwc2_hsotg *hsotg);
+void dwc2_drd_suspend(struct dwc2_hsotg *hsotg);
+void dwc2_drd_resume(struct dwc2_hsotg *hsotg);
+void dwc2_drd_exit(struct dwc2_hsotg *hsotg);
+
/*
* Dump core registers and SPRAM
*/
@@ -1392,6 +1399,7 @@ int dwc2_hsotg_resume(struct dwc2_hsotg *dwc2);
int dwc2_gadget_init(struct dwc2_hsotg *hsotg);
void dwc2_hsotg_core_init_disconnected(struct dwc2_hsotg *dwc2,
bool reset);
+void dwc2_hsotg_core_disconnect(struct dwc2_hsotg *hsotg);
void dwc2_hsotg_core_connect(struct dwc2_hsotg *hsotg);
void dwc2_hsotg_disconnect(struct dwc2_hsotg *dwc2);
int dwc2_hsotg_set_test_mode(struct dwc2_hsotg *hsotg, int testmode);
diff --git a/drivers/usb/dwc2/drd.c b/drivers/usb/dwc2/drd.c
new file mode 100644
index 000000000000..032efffa37ab
--- /dev/null
+++ b/drivers/usb/dwc2/drd.c
@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * drd.c - DesignWare USB2 DRD Controller Dual-role support
+ *
+ * Copyright (C) 2020 STMicroelectronics
+ *
+ * Author(s): Amelie Delaunay <amelie.delaunay@xxxxxx>
+ */
+
+#include <linux/iopoll.h>
+#include <linux/platform_device.h>
+#include <linux/usb/role.h>
+#include "core.h"
+
+static void dwc2_ovr_init(struct dwc2_hsotg *hsotg)
+{
+ unsigned long flags;
+ u32 gotgctl;
+
+ spin_lock_irqsave(&hsotg->lock, flags);
+
+ gotgctl = dwc2_readl(hsotg, GOTGCTL);
+ gotgctl |= GOTGCTL_BVALOEN | GOTGCTL_AVALOEN | GOTGCTL_VBVALOEN;
+ gotgctl |= GOTGCTL_DBNCE_FLTR_BYPASS;
+ gotgctl &= ~(GOTGCTL_BVALOVAL | GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL);
+ dwc2_writel(hsotg, gotgctl, GOTGCTL);
+
+ dwc2_force_mode(hsotg, false);
+
+ spin_unlock_irqrestore(&hsotg->lock, flags);
+}
+
+static int dwc2_ovr_avalid(struct dwc2_hsotg *hsotg, bool valid)
+{
+ u32 gotgctl = dwc2_readl(hsotg, GOTGCTL);
+
+ /* Check if A-Session is already in the right state */
+ if ((valid && (gotgctl & GOTGCTL_ASESVLD)) ||
+ (!valid && !(gotgctl & GOTGCTL_ASESVLD)))
+ return -EALREADY;
+
+ if (valid)
+ gotgctl |= GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL;
+ else
+ gotgctl &= ~(GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL);
+ dwc2_writel(hsotg, gotgctl, GOTGCTL);
+
+ return 0;
+}
+
+static int dwc2_ovr_bvalid(struct dwc2_hsotg *hsotg, bool valid)
+{
+ u32 gotgctl = dwc2_readl(hsotg, GOTGCTL);
+
+ /* Check if B-Session is already in the right state */
+ if ((valid && (gotgctl & GOTGCTL_BSESVLD)) ||
+ (!valid && !(gotgctl & GOTGCTL_BSESVLD)))
+ return -EALREADY;
+
+ if (valid)
+ gotgctl |= GOTGCTL_BVALOVAL | GOTGCTL_VBVALOVAL;
+ else
+ gotgctl &= ~(GOTGCTL_BVALOVAL | GOTGCTL_VBVALOVAL);
+ dwc2_writel(hsotg, gotgctl, GOTGCTL);
+
+ return 0;
+}
+
+static int dwc2_drd_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
+{
+ struct dwc2_hsotg *hsotg = usb_role_switch_get_drvdata(sw);
+ unsigned long flags;
+
+ /* Skip session not in line with dr_mode */
+ if ((role == USB_ROLE_DEVICE && hsotg->dr_mode == USB_DR_MODE_HOST) ||
+ (role == USB_ROLE_HOST && hsotg->dr_mode == USB_DR_MODE_PERIPHERAL))
+ return -EINVAL;
+
+ /* Skip session if core is in test mode */
+ if (role == USB_ROLE_NONE && hsotg->test_mode) {
+ dev_dbg(hsotg->dev, "Core is in test mode\n");
+ return -EBUSY;
+ }
+
+ spin_lock_irqsave(&hsotg->lock, flags);
+
+ if (role == USB_ROLE_HOST) {
+ if (dwc2_ovr_avalid(hsotg, true))
+ goto unlock;
+
+ if (hsotg->dr_mode == USB_DR_MODE_OTG)
+ /*
+ * This will raise a Connector ID Status Change
+ * Interrupt - connID A
+ */
+ dwc2_force_mode(hsotg, true);
+ } else if (role == USB_ROLE_DEVICE) {
+ if (dwc2_ovr_bvalid(hsotg, true))
+ goto unlock;
+
+ if (hsotg->dr_mode == USB_DR_MODE_OTG)
+ /*
+ * This will raise a Connector ID Status Change
+ * Interrupt - connID B
+ */
+ dwc2_force_mode(hsotg, false);
+
+ /* This clear DCTL.SFTDISCON bit */
+ dwc2_hsotg_core_connect(hsotg);
+ } else {
+ if (dwc2_is_device_mode(hsotg)) {
+ if (!dwc2_ovr_bvalid(hsotg, false))
+ /* This set DCTL.SFTDISCON bit */
+ dwc2_hsotg_core_disconnect(hsotg);
+ } else {
+ dwc2_ovr_avalid(hsotg, false);
+ }
+ }
+
+unlock:
+ spin_unlock_irqrestore(&hsotg->lock, flags);
+
+ dev_dbg(hsotg->dev, "%s-session valid\n",
+ role == USB_ROLE_NONE ? "No" :
+ role == USB_ROLE_HOST ? "A" : "B");
+
+ return 0;
+}
+
+int dwc2_drd_init(struct dwc2_hsotg *hsotg)
+{
+ struct usb_role_switch_desc role_sw_desc = {0};
+ struct usb_role_switch *role_sw;
+ int ret;
+
+ if (!device_property_read_bool(hsotg->dev, "usb-role-switch"))
+ return 0;
+
+ role_sw_desc.driver_data = hsotg;
+ role_sw_desc.fwnode = dev_fwnode(hsotg->dev);
+ role_sw_desc.set = dwc2_drd_role_sw_set;
+ role_sw_desc.allow_userspace_control = true;
+
+ role_sw = usb_role_switch_register(hsotg->dev, &role_sw_desc);
+ if (IS_ERR(role_sw)) {
+ ret = PTR_ERR(role_sw);
+ dev_err(hsotg->dev,
+ "failed to register role switch: %d\n", ret);
+ return ret;
+ }
+
+ hsotg->role_sw = role_sw;
+
+ /* Enable override and initialize values */
+ dwc2_ovr_init(hsotg);
+
+ return 0;
+}
+
+void dwc2_drd_suspend(struct dwc2_hsotg *hsotg)
+{
+ u32 gintsts, gintmsk;
+
+ if (hsotg->role_sw && !hsotg->params.external_id_pin_ctl) {
+ gintmsk = dwc2_readl(hsotg, GINTMSK);
+ gintmsk &= ~GINTSTS_CONIDSTSCHNG;
+ dwc2_writel(hsotg, gintmsk, GINTMSK);
+ gintsts = dwc2_readl(hsotg, GINTSTS);
+ dwc2_writel(hsotg, gintsts | GINTSTS_CONIDSTSCHNG, GINTSTS);
+ }
+}
+
+void dwc2_drd_resume(struct dwc2_hsotg *hsotg)
+{
+ u32 gintsts, gintmsk;
+
+ if (hsotg->role_sw && !hsotg->params.external_id_pin_ctl) {
+ gintsts = dwc2_readl(hsotg, GINTSTS);
+ dwc2_writel(hsotg, gintsts | GINTSTS_CONIDSTSCHNG, GINTSTS);
+ gintmsk = dwc2_readl(hsotg, GINTMSK);
+ gintmsk |= GINTSTS_CONIDSTSCHNG;
+ dwc2_writel(hsotg, gintmsk, GINTMSK);
+ }
+}
+
+void dwc2_drd_exit(struct dwc2_hsotg *hsotg)
+{
+ if (hsotg->role_sw)
+ usb_role_switch_unregister(hsotg->role_sw);
+}
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 12b98b466287..e7702252d48c 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -3532,7 +3532,7 @@ void dwc2_hsotg_core_init_disconnected(struct dwc2_hsotg *hsotg,
dwc2_readl(hsotg, DOEPCTL0));
}
-static void dwc2_hsotg_core_disconnect(struct dwc2_hsotg *hsotg)
+void dwc2_hsotg_core_disconnect(struct dwc2_hsotg *hsotg)
{
/* set the soft-disconnect bit */
dwc2_set_bit(hsotg, DCTL, DCTL_SFTDISCON);
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index e571c8ae65ec..629a119f04b7 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -317,6 +317,8 @@ static int dwc2_driver_remove(struct platform_device *dev)
if (hsotg->params.activate_stm_id_vb_detection)
regulator_disable(hsotg->usb33d);
+ dwc2_drd_exit(hsotg);
+
if (hsotg->ll_hw_enabled)
dwc2_lowlevel_hw_disable(hsotg);
@@ -532,6 +534,13 @@ static int dwc2_driver_probe(struct platform_device *dev)
dwc2_writel(hsotg, ggpio, GGPIO);
}
+ retval = dwc2_drd_init(hsotg);
+ if (retval) {
+ if (retval != -EPROBE_DEFER)
+ dev_err(hsotg->dev, "failed to initialize dual-role\n");
+ goto error_init;
+ }
+
if (hsotg->dr_mode != USB_DR_MODE_HOST) {
retval = dwc2_gadget_init(hsotg);
if (retval)
@@ -594,6 +603,8 @@ static int __maybe_unused dwc2_suspend(struct device *dev)
if (is_device_mode)
dwc2_hsotg_suspend(dwc2);
+ dwc2_drd_suspend(dwc2);
+
if (dwc2->params.activate_stm_id_vb_detection) {
unsigned long flags;
u32 ggpio, gotgctl;
@@ -674,6 +685,8 @@ static int __maybe_unused dwc2_resume(struct device *dev)
/* Need to restore FORCEDEVMODE/FORCEHOSTMODE */
dwc2_force_dr_mode(dwc2);
+ dwc2_drd_resume(dwc2);
+
if (dwc2_is_device_mode(dwc2))
ret = dwc2_hsotg_resume(dwc2);
--
2.17.1