Re: [PATCH v2 2/6] usb: phy: mxs: keep USBPHY2's clk always on

Peter Chen
2024-08-09T01:37:42Z

On 24-07-26 19:32:03, Xu Yang wrote:
> IP require keep USBPHY2's clk always on, so USBPHY2 (PLL7) power can be
> controlled by suspend signal. USB remote wakeup needs resume signal be
> sent out as soon as possible to match USB requirements.
>
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

Reviewed-by: Peter Chen <peter.chen@kernel.org>
>
> ---
> Changes in v2:
> - modify commit message
> - remove hardware_control_phy2_clk
> ---
> drivers/usb/phy/phy-mxs-usb.c | 33 ++++++++++++++++++++++++++-------
> 1 file changed, 26 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c
> index d9d29f0b37de..e172af75f602 100644
> --- a/drivers/usb/phy/phy-mxs-usb.c
> +++ b/drivers/usb/phy/phy-mxs-usb.c
> @@ -150,6 +150,15 @@
> #define MXS_PHY_TX_D_CAL_MIN 79
> #define MXS_PHY_TX_D_CAL_MAX 119
>
> +/*
> + * At imx6q/6sl/6sx, the PHY2's clock is controlled by hardware directly,
> + * eg, according to PHY's suspend status. In these PHYs, we only need to
> + * open the clock at the initialization and close it at its shutdown routine.
> + * These PHYs can send resume signal without software interfere if not
> + * gate clock.
> + */
> +#define MXS_PHY_HARDWARE_CONTROL_PHY2_CLK BIT(4)
> +
> struct mxs_phy_data {
> unsigned int flags;
> };
> @@ -161,12 +170,14 @@ static const struct mxs_phy_data imx23_phy_data = {
> static const struct mxs_phy_data imx6q_phy_data = {
> .flags = MXS_PHY_SENDING_SOF_TOO_FAST |
> MXS_PHY_DISCONNECT_LINE_WITHOUT_VBUS |
> - MXS_PHY_NEED_IP_FIX,
> + MXS_PHY_NEED_IP_FIX |
> + MXS_PHY_HARDWARE_CONTROL_PHY2_CLK,
> };
>
> static const struct mxs_phy_data imx6sl_phy_data = {
> .flags = MXS_PHY_DISCONNECT_LINE_WITHOUT_VBUS |
> - MXS_PHY_NEED_IP_FIX,
> + MXS_PHY_NEED_IP_FIX |
> + MXS_PHY_HARDWARE_CONTROL_PHY2_CLK,
> };
>
> static const struct mxs_phy_data vf610_phy_data = {
> @@ -175,7 +186,8 @@ static const struct mxs_phy_data vf610_phy_data = {
> };
>
> static const struct mxs_phy_data imx6sx_phy_data = {
> - .flags = MXS_PHY_DISCONNECT_LINE_WITHOUT_VBUS,
> + .flags = MXS_PHY_DISCONNECT_LINE_WITHOUT_VBUS |
> + MXS_PHY_HARDWARE_CONTROL_PHY2_CLK,
> };
>
> static const struct mxs_phy_data imx6ul_phy_data = {
> @@ -518,12 +530,19 @@ static int mxs_phy_suspend(struct usb_phy *x, int suspend)
> }
> writel(BM_USBPHY_CTRL_CLKGATE,
> x->io_priv + HW_USBPHY_CTRL_SET);
> - clk_disable_unprepare(mxs_phy->clk);
> + if (!(mxs_phy->port_id == 1 &&
> + (mxs_phy->data->flags &
> + MXS_PHY_HARDWARE_CONTROL_PHY2_CLK)))
> + clk_disable_unprepare(mxs_phy->clk);
> } else {
> mxs_phy_clock_switch_delay();
> - ret = clk_prepare_enable(mxs_phy->clk);
> - if (ret)
> - return ret;
> + if (!(mxs_phy->port_id == 1 &&
> + (mxs_phy->data->flags &
> + MXS_PHY_HARDWARE_CONTROL_PHY2_CLK))) {
> + ret = clk_prepare_enable(mxs_phy->clk);
> + if (ret)
> + return ret;
> + }
> writel(BM_USBPHY_CTRL_CLKGATE,
> x->io_priv + HW_USBPHY_CTRL_CLR);
> writel(0, x->io_priv + HW_USBPHY_PWD);
> --
> 2.34.1
>