On Wed, 2020-05-13 at 16:07 +0300, Roger Quadros wrote:
> The Local Power Sleep Controller (LPSC) dependency on AM65
> requires SERDES0 to be powered on before USB.
>
> We need to power up SERDES0 power domain and hold it on
> throughout the reset, init, power on sequence.
>
> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> ---
> drivers/usb/dwc3/dwc3-keystone.c | 47 +++++++++++++++++++++++++++++++-
> 1 file changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc3/dwc3-keystone.c b/drivers/usb/dwc3/dwc3-keystone.c
> index 1e14a6f4884b..46d46f3507fc 100644
> --- a/drivers/usb/dwc3/dwc3-keystone.c
> +++ b/drivers/usb/dwc3/dwc3-keystone.c
> @@ -14,6 +14,7 @@
> #include <linux/dma-mapping.h>
> #include <linux/io.h>
> #include <linux/of_platform.h>
> +#include <linux/phy/phy.h>
> #include <linux/pm_runtime.h>
>
> /* USBSS register offsets */
> @@ -34,6 +35,7 @@
> struct dwc3_keystone {
> struct device *dev;
> void __iomem *usbss;
> + struct phy *usb3_phy;
> };
>
> static inline u32 kdwc3_readl(void __iomem *base, u32 offset)
> @@ -95,8 +97,44 @@ static int kdwc3_probe(struct platform_device *pdev)
> if (IS_ERR(kdwc->usbss))
> return PTR_ERR(kdwc->usbss);
>
> - pm_runtime_enable(kdwc->dev);
> + /* PSC dependency on AM65 needs SERDES0 to be powered before USB0 */
> + kdwc->usb3_phy = devm_phy_get(dev, "usb3-phy");
Use devm_phy_optional_get() instead?
> + if (IS_ERR(kdwc->usb3_phy)) {
> + error = PTR_ERR(kdwc->usb3_phy);
> + if (error == -ENOSYS || error == -ENODEV) {
> + kdwc->usb3_phy = NULL;
> + } else {
> + if (error != -EPROBE_DEFER) {
> + dev_err(dev, "couldn't get usb3 phy: %d\n",
> + error);
> + }
> +
> + return error;
> + }
> + }
> +
> + phy_pm_runtime_get_sync(kdwc->usb3_phy);
> +
> + error = phy_reset(kdwc->usb3_phy);
> + if (error < 0) {
> + dev_err(dev, "usb3 phy reset failed: %d\n", error);
> + return error;
> + }
> +
> + error = phy_init(kdwc->usb3_phy);
> + if (error < 0) {
> + dev_err(dev, "usb3 phy init failed: %d\n", error);
> + return error;
> + }
>
> + error = phy_power_on(kdwc->usb3_phy);
> + if (error < 0) {
> + dev_err(dev, "usb3 phy power on failed: %d\n", error);
> + phy_exit(kdwc->usb3_phy);
> + return error;
> + }
> +
> + pm_runtime_enable(kdwc->dev);
> error = pm_runtime_get_sync(kdwc->dev);
> if (error < 0) {
> dev_err(kdwc->dev, "pm_runtime_get_sync failed, error %d\n",
> @@ -138,6 +176,9 @@ static int kdwc3_probe(struct platform_device *pdev)
> err_irq:
> pm_runtime_put_sync(kdwc->dev);
> pm_runtime_disable(kdwc->dev);
> + phy_power_off(kdwc->usb3_phy);
> + phy_exit(kdwc->usb3_phy);
> + phy_pm_runtime_put_sync(kdwc->usb3_phy);
>
> return error;
> }
> @@ -163,6 +204,10 @@ static int kdwc3_remove(struct platform_device *pdev)
> pm_runtime_put_sync(kdwc->dev);
> pm_runtime_disable(kdwc->dev);
>
> + phy_power_off(kdwc->usb3_phy);
> + phy_exit(kdwc->usb3_phy);
> + phy_pm_runtime_put_sync(kdwc->usb3_phy);
> +
> platform_set_drvdata(pdev, NULL);
>
> return 0;
