On Thu, Aug 29, 2019 at 04:12:07PM +0530, Saranya Gopal wrote: > Enable static DRD mode in Intel platforms which guarantees > successful role switch all the time. This fixes issues like > software role switch failure after cold boot and issue with > role switch when USB 3.0 cable is used. But, do not enable > static DRD mode for Cherrytrail devices which rely on firmware > for role switch. > > Signed-off-by: Saranya Gopal <[email protected]> > Signed-off-by: Balaji Manoharan <[email protected]>
Reviewed-by: Heikki Krogerus <[email protected]> > --- > changes since v3: Initialized drd_config variable to fix warning > changes since v2: Revised SoB tags > changes since v1: Added drd_config to avoid multiple if checks > Other minor changes suggested by Hans > > drivers/usb/roles/intel-xhci-usb-role-switch.c | 27 > ++++++++++++++++++++++++-- > 1 file changed, 25 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/roles/intel-xhci-usb-role-switch.c > b/drivers/usb/roles/intel-xhci-usb-role-switch.c > index 277de96..88d0416 100644 > --- a/drivers/usb/roles/intel-xhci-usb-role-switch.c > +++ b/drivers/usb/roles/intel-xhci-usb-role-switch.c > @@ -19,6 +19,7 @@ > #include <linux/module.h> > #include <linux/platform_device.h> > #include <linux/pm_runtime.h> > +#include <linux/property.h> > #include <linux/usb/role.h> > > /* register definition */ > @@ -26,6 +27,12 @@ > #define SW_VBUS_VALID BIT(24) > #define SW_IDPIN_EN BIT(21) > #define SW_IDPIN BIT(20) > +#define SW_SWITCH_EN BIT(16) > + > +#define DRD_CONFIG_DYNAMIC 0 > +#define DRD_CONFIG_STATIC_HOST 1 > +#define DRD_CONFIG_STATIC_DEVICE 2 > +#define DRD_CONFIG_MASK 3 > > #define DUAL_ROLE_CFG1 0x6c > #define HOST_MODE BIT(29) > @@ -37,6 +44,7 @@ > struct intel_xhci_usb_data { > struct usb_role_switch *role_sw; > void __iomem *base; > + bool enable_sw_switch; > }; > > static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role) > @@ -45,6 +53,7 @@ static int intel_xhci_usb_set_role(struct device *dev, enum > usb_role role) > unsigned long timeout; > acpi_status status; > u32 glk, val; > + u32 drd_config = DRD_CONFIG_DYNAMIC; > > /* > * On many CHT devices ACPI event (_AEI) handlers read / modify / > @@ -59,24 +68,35 @@ static int intel_xhci_usb_set_role(struct device *dev, > enum usb_role role) > > pm_runtime_get_sync(dev); > > - /* Set idpin value as requested */ > + /* > + * Set idpin value as requested. > + * Since some devices rely on firmware setting DRD_CONFIG and > + * SW_SWITCH_EN bits to be zero for role switch, > + * do not set these bits for those devices. > + */ > val = readl(data->base + DUAL_ROLE_CFG0); > switch (role) { > case USB_ROLE_NONE: > val |= SW_IDPIN; > val &= ~SW_VBUS_VALID; > + drd_config = DRD_CONFIG_DYNAMIC; > break; > case USB_ROLE_HOST: > val &= ~SW_IDPIN; > val &= ~SW_VBUS_VALID; > + drd_config = DRD_CONFIG_STATIC_HOST; > break; > case USB_ROLE_DEVICE: > val |= SW_IDPIN; > val |= SW_VBUS_VALID; > + drd_config = DRD_CONFIG_STATIC_DEVICE; > break; > } > val |= SW_IDPIN_EN; > - > + if (data->enable_sw_switch) { > + val &= ~DRD_CONFIG_MASK; > + val |= SW_SWITCH_EN | drd_config; > + } > writel(val, data->base + DUAL_ROLE_CFG0); > > acpi_release_global_lock(glk); > @@ -147,6 +167,9 @@ static int intel_xhci_usb_probe(struct platform_device > *pdev) > > platform_set_drvdata(pdev, data); > > + data->enable_sw_switch = !device_property_read_bool(dev, > + "sw_switch_disable"); > + > data->role_sw = usb_role_switch_register(dev, &sw_desc); > if (IS_ERR(data->role_sw)) > return PTR_ERR(data->role_sw); > -- > 1.9.1 thanks, -- heikki
