Re: [PATCH v4 03/16] phy: qcom-qmp: Power-on PHY before initialization

[Vivek Gautam]

On Wed, Jan 3, 2018 at 4:58 PM, Manu Gautam <mgautam@xxxxxxxxxxxxxx> wrote:
> PHY regulators which are enabled from power_on() must be ON
> before turning-on clocks and initializing it as part of init().
> As most of the core drivers perform power_on() after init(), move
> PHY regulators enable to com_init() and use power_on() to
> only enable pipe_clk. This pipe_clk is output from PHY and some
> core drivers e.g. PCIe follow specific sequence after phy_init()
> that mandates pipe_clk to be enabled from power_on() only.
> On similar lines move clk_enable from init() to com_init() which
> executes once for multi lane PHYs.
>
> Signed-off-by: Manu Gautam <mgautam@xxxxxxxxxxxxxx>
> ---

Adding Subhash Jadvani to look at this change from UFS perspective.

>  drivers/phy/qualcomm/phy-qcom-qmp.c | 61 +++++++++++++++----------------------
>  1 file changed, 24 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
> index 5fed1ae..1b82cea 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
> @@ -724,36 +724,13 @@ static int qcom_qmp_phy_poweron(struct phy *phy)
>  {
>         struct qmp_phy *qphy = phy_get_drvdata(phy);
>         struct qcom_qmp *qmp = qphy->qmp;
> -       int num = qmp->cfg->num_vregs;
>         int ret;
>
> -       dev_vdbg(&phy->dev, "Powering on QMP phy\n");
> -
> -       /* turn on regulator supplies */
> -       ret = regulator_bulk_enable(num, qmp->vregs);
> -       if (ret) {
> -               dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
> -               return ret;
> -       }
> -
>         ret = clk_prepare_enable(qphy->pipe_clk);
> -       if (ret) {
> +       if (ret)
>                 dev_err(qmp->dev, "pipe_clk enable failed, err=%d\n", ret);
> -               regulator_bulk_disable(num, qmp->vregs);
> -               return ret;
> -       }
>
> -       return 0;
> -}
> -
> -static int qcom_qmp_phy_poweroff(struct phy *phy)
> -{
> -       struct qmp_phy *qphy = phy_get_drvdata(phy);
> -       struct qcom_qmp *qmp = qphy->qmp;
> -
> -       regulator_bulk_disable(qmp->cfg->num_vregs, qmp->vregs);
> -
> -       return 0;
> +       return ret;
>  }
>
>  static int qcom_qmp_phy_com_init(struct qcom_qmp *qmp)
> @@ -768,6 +745,19 @@ static int qcom_qmp_phy_com_init(struct qcom_qmp *qmp)
>                 return 0;
>         }
>
> +       /* turn on regulator supplies */
> +       ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
> +       if (ret) {
> +               dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
> +               goto err_reg_enable;
> +       }
> +
> +       ret = clk_bulk_prepare_enable(cfg->num_clks, qmp->clks);
> +       if (ret) {
> +               dev_err(qmp->dev, "failed to enable clks, err=%d\n", ret);
> +               goto err_clk_enable;
> +       }
> +
>         for (i = 0; i < cfg->num_resets; i++) {
>                 ret = reset_control_deassert(qmp->resets[i]);
>                 if (ret) {
> @@ -812,6 +802,10 @@ static int qcom_qmp_phy_com_init(struct qcom_qmp *qmp)
>  err_rst:
>         while (--i >= 0)
>                 reset_control_assert(qmp->resets[i]);
> +       clk_bulk_disable_unprepare(cfg->num_clks, qmp->clks);
> +err_clk_enable:
> +       regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
> +err_reg_enable:
>         mutex_unlock(&qmp->phy_mutex);
>
>         return ret;
> @@ -841,6 +835,10 @@ static int qcom_qmp_phy_com_exit(struct qcom_qmp *qmp)
>         while (--i >= 0)
>                 reset_control_assert(qmp->resets[i]);
>
> +       clk_bulk_disable_unprepare(cfg->num_clks, qmp->clks);
> +
> +       regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
> +
>         mutex_unlock(&qmp->phy_mutex);
>
>         return 0;
> @@ -861,15 +859,9 @@ static int qcom_qmp_phy_init(struct phy *phy)
>
>         dev_vdbg(qmp->dev, "Initializing QMP phy\n");
>
> -       ret = clk_bulk_prepare_enable(cfg->num_clks, qmp->clks);
> -       if (ret) {
> -               dev_err(qmp->dev, "failed to enable clks, err=%d\n", ret);
> -               return ret;
> -       }
> -
>         ret = qcom_qmp_phy_com_init(qmp);
>         if (ret)
> -               goto err_com_init;
> +               return ret;
>
>         if (cfg->has_lane_rst) {
>                 ret = reset_control_deassert(qphy->lane_rst);
> @@ -917,8 +909,6 @@ static int qcom_qmp_phy_init(struct phy *phy)
>                 reset_control_assert(qphy->lane_rst);
>  err_lane_rst:
>         qcom_qmp_phy_com_exit(qmp);
> -err_com_init:
> -       clk_bulk_disable_unprepare(cfg->num_clks, qmp->clks);
>
>         return ret;
>  }
> @@ -945,8 +935,6 @@ static int qcom_qmp_phy_exit(struct phy *phy)
>
>         qcom_qmp_phy_com_exit(qmp);
>
> -       clk_bulk_disable_unprepare(cfg->num_clks, qmp->clks);
> -
>         return 0;
>  }
>
> @@ -1060,7 +1048,6 @@ static int phy_pipe_clk_register(struct qcom_qmp *qmp, struct device_node *np)
>         .init           = qcom_qmp_phy_init,
>         .exit           = qcom_qmp_phy_exit,
>         .power_on       = qcom_qmp_phy_poweron,
> -       .power_off      = qcom_qmp_phy_poweroff,
>         .owner          = THIS_MODULE,
>  };
>
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