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 <saranya.gopal@xxxxxxxxx>
> Signed-off-by: Balaji Manoharan <m.balaji@xxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> 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
