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

Vivek Gautam
2018-01-12T08:27:07Z

On Wed, Jan 3, 2018 at 4:58 PM, Manu Gautam <mgautam-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> 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-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> ---

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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