Re: [PATCH 13/15] phy: qcom-qmp-pcie: add support for pipediv2 clock

Dmitry Baryshkov
2022-10-18T13:05:38Z

On 17/10/2022 17:53, Johan Hovold wrote:
> Some QMP PHYs have a second fixed-divider pipe clock that needs to be
> enabled along with the pipe clock.
>
> Add support for an optional "pipediv2" clock.
>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
> drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 42 ++++++++++++++++++++----
> 1 file changed, 36 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> index 9c8e009033f1..c1d74c06fad1 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> @@ -1379,7 +1379,9 @@ struct qmp_pcie {
> void __iomem *rx2;
>
> struct clk *pipe_clk;
> + struct clk *pipediv2_clk;
> struct clk_bulk_data *clks;
> +
> struct reset_control_bulk_data *resets;
> struct regulator_bulk_data *vregs;
>
> @@ -1902,6 +1904,36 @@ static int qmp_pcie_exit(struct phy *phy)
> return 0;
> }
>
> +static int pipe_clk_enable(struct qmp_pcie *qmp)
> +{
> + int ret;
> +
> + ret = clk_prepare_enable(qmp->pipe_clk);
> + if (ret) {
> + dev_err(qmp->dev, "failed to enable pipe clock: %d\n", ret);
> + return ret;
> + }
> +
> + ret = clk_prepare_enable(qmp->pipediv2_clk);
> + if (ret) {
> + dev_err(qmp->dev, "failed to enable pipediv2 clock: %d\n", ret);
> + goto err_disable_pipe_clk;
> + }

Do they have to be enabled in sequence? If not, I'd use a bulk clocks
here for the pipe clocks. While it can look like an overkill, it would
be a safe net for the possible future changes, which might include
additional clocks.

> +
> + return 0;
> +
> +err_disable_pipe_clk:
> + clk_disable_unprepare(qmp->pipe_clk);
> +
> + return ret;
> +}
> +
> +static void pipe_clk_disable(struct qmp_pcie *qmp)
> +{
> + clk_disable_unprepare(qmp->pipediv2_clk);
> + clk_disable_unprepare(qmp->pipe_clk);
> +}
> +
> static int qmp_pcie_power_on(struct phy *phy)
> {
> struct qmp_pcie *qmp = phy_get_drvdata(phy);
> @@ -1923,11 +1955,9 @@ static int qmp_pcie_power_on(struct phy *phy)
> qmp_pcie_init_registers(qmp, &cfg->tables);
> qmp_pcie_init_registers(qmp, mode_tables);
>
> - ret = clk_prepare_enable(qmp->pipe_clk);
> - if (ret) {
> - dev_err(qmp->dev, "pipe_clk enable failed err=%d\n", ret);
> + ret = pipe_clk_enable(qmp);
> + if (ret)
> return ret;
> - }
>
> /* Pull PHY out of reset state */
> qphy_clrbits(pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);
> @@ -1950,7 +1980,7 @@ static int qmp_pcie_power_on(struct phy *phy)
> return 0;
>
> err_disable_pipe_clk:
> - clk_disable_unprepare(qmp->pipe_clk);
> + pipe_clk_disable(qmp);
>
> return ret;
> }
> @@ -1960,7 +1990,7 @@ static int qmp_pcie_power_off(struct phy *phy)
> struct qmp_pcie *qmp = phy_get_drvdata(phy);
> const struct qmp_phy_cfg *cfg = qmp->cfg;
>
> - clk_disable_unprepare(qmp->pipe_clk);
> + pipe_clk_disable(qmp);
>
> /* PHY reset */
> qphy_setbits(qmp->pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);

--
With best wishes
Dmitry