usb: dwc2: drd: fix inconsistent mode if role-switch-default-mode="host"

Some boards might use USB-A female connector for USB ports, however,
the port could be connected to a dual-mode USB controller, making it
also behaves as a peripheral device if male-to-male cable is connected.

In this case, the dts looks like this:

&usb0 {
status = "okay";
dr_mode = "otg";
usb-role-switch;
role-switch-default-mode = "host";
};

After boot, dwc2_ovr_init() sets GOTGCTL to GOTGCTL_AVALOVAL and call
dwc2_force_mode() with parameter host=false, which causes inconsistent
mode - The hardware is in peripheral mode while the kernel status is
in host mode.

What we can do now is to call dwc2_drd_role_sw_set() to switch to
device mode, and everything should work just fine now, even switching
back to none(default) mode afterwards.

Fixes: e14acb876985 ("usb: dwc2: drd: add role-switch-default-node support")
Cc: stable <stable@kernel.org>
Signed-off-by: Ziyang Huang <hzyitc@outlook.com>
Tested-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Reviewed-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/SG2PR01MB204837BF68EDB0E343D2A375C9A59@SG2PR01MB2048.apcprd01.prod.exchangelabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: dwc2: drd: fix soft connect when gadget is unconfigured

When the gadget driver hasn't been (yet) configured, and the cable is
connected to a HOST, the SFTDISCON gets cleared unconditionally, so the
HOST tries to enumerate it.
At the host side, this can result in a stuck USB port or worse. When
getting lucky, some dmesg can be observed at the host side:
new high-speed USB device number ...
device descriptor read/64, error -110

Fix it in drd, by checking the enabled flag before calling
dwc2_hsotg_core_connect(). It will be called later, once configured,
by the normal flow:
- udc_bind_to_driver
- usb_gadget_connect
- dwc2_hsotg_pullup
- dwc2_hsotg_core_connect

Fixes: 17f934024e84 ("usb: dwc2: override PHY input signals with usb role switch support")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/1644999135-13478-1-git-send-email-fabrice.gasnier@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "usb: dwc2: drd: fix soft connect when gadget is unconfigured"

This reverts commit 269cbcf7b72de6f0016806d4a0cec1d689b55a87.

It causes build errors as reported by the kernel test robot.

Link: https://lore.kernel.org/r/202202112236.AwoOTtHO-lkp@intel.com
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 269cbcf7b72d ("usb: dwc2: drd: fix soft connect when gadget is unconfigured")
Cc: stable@kernel.org
Cc: Amelie Delaunay <amelie.delaunay@foss.st.com>
Cc: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Cc: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: dwc2: drd: fix soft connect when gadget is unconfigured

When the gadget driver hasn't been (yet) configured, and the cable is
connected to a HOST, the SFTDISCON gets cleared unconditionally, so the
HOST tries to enumerate it.
At the host side, this can result in a stuck USB port or worse. When
getting lucky, some dmesg can be observed at the host side:
new high-speed USB device number ...
device descriptor read/64, error -110

Fix it in drd, by checking the enabled flag before calling
dwc2_hsotg_core_connect(). It will be called later, once configured,
by the normal flow:
- udc_bind_to_driver
- usb_gadget_connect
- dwc2_hsotg_pullup
- dwc2_hsotg_core_connect

Fixes: 17f934024e84 ("usb: dwc2: override PHY input signals with usb role switch support")
Cc: stable@kernel.org
Reviewed-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/1644423353-17859-1-git-send-email-fabrice.gasnier@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: dwc2: drd: restore role and overrides upon resume

Override enable bits may not be restored when going to low power mode
(e.g. when in DWC2_POWER_DOWN_PARAM_NONE).
These bits are set when probing/initializing drd (role switch). Restore
them upon resume from low power mode (in case these have been lost).

To achieve this, the last known role is restored upon resume. And the
override enable bits are always set when configuring aval, bval and vbval.

When resuming, forcing the role should be done only once, or this can cause
port changes in HOST mode for instance.
So, only restore FORCEDEVMODE/FORCEHOSTMODE when role_sw is unused

Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/1638806203-6624-4-git-send-email-fabrice.gasnier@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: dwc2: drd: add role-switch-default-node support

When using usb-role-switch, while the usb role is not yet define
(USB_ROLE_NONE), the user may want to configure the default mode to host
or device.
Use role-switch-default-mode for that purpose.

Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/1638806203-6624-3-git-send-email-fabrice.gasnier@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: dwc2: drd: reset current session before setting the new one

If role is changed without the "none" step, A- and B- valid session could
be set at the same time. It is an issue.
This patch resets A-session if role switch sets B-session, and resets
B-session if role switch sets A-session.
Then, it is possible to change the role without the "none" step.

Fixes: 17f934024e84 ("usb: dwc2: override PHY input signals with usb role switch support")
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/20211005095305.66397-4-amelie.delaunay@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: dwc2: drd: fix dwc2_drd_role_sw_set when clock could be disabled

In case of USB_DR_MODE_PERIPHERAL, the OTG clock is disabled at the end of
the probe (it is not the case if USB_DR_MODE_HOST or USB_DR_MODE_OTG).
The clock is then enabled on udc_start.
If dwc2_drd_role_sw_set is called before udc_start (it is the case if the
usb cable is plugged at boot), GOTGCTL and GUSBCFG registers cannot be
read/written, so session cannot be overridden.
To avoid this case, check the ll_hw_enabled value and enable the clock if
it is available, and disable it after the override.

Fixes: 17f934024e84 ("usb: dwc2: override PHY input signals with usb role switch support")
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/20211005095305.66397-3-amelie.delaunay@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: dwc2: drd: fix dwc2_force_mode call in dwc2_ovr_init

Instead of forcing the role to Device, check the dr_mode configuration.
If the core is Host only, force the mode to Host, this to avoid the
dwc2_force_mode warning:
WARNING: CPU: 1 PID: 21 at drivers/usb/dwc2/core.c:615 dwc2_drd_init+0x104/0x17c

When forcing mode to Host, dwc2_force_mode may sleep the time the host
role is applied. To avoid sleeping while atomic context, move the call
to dwc2_force_mode after spin_unlock_irqrestore. It is safe, as
interrupts are not yet unmasked here.

Fixes: 17f934024e84 ("usb: dwc2: override PHY input signals with usb role switch support")
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/20211005095305.66397-2-amelie.delaunay@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: dwc2: override PHY input signals with usb role switch support

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

Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

Revert "usb: dwc2: override PHY input signals with usb role switch support"

This reverts commit bc0f0d4a5853e32ba97a0318f774570428fc5634.

It was not meant to be applied yet.

Cc: Minas Harutyunyan <hminas@synopsys.com>
Cc: Amelie Delaunay <amelie.delaunay@st.com>
Cc: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: dwc2: override PHY input signals with usb role switch support

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

Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>