[PATCH v2 1/2] phy: qcom-snps-femto-v2: properly enable ref clock
Konrad Dybcio
konrad.dybcio at linaro.org
Mon Jun 5 16:14:00 PDT 2023
On 5.06.2023 20:44, Adrien Thierry wrote:
> The driver is not enabling the ref clock, which thus gets disabled by
> the clk_disable_unused initcall. This leads to the dwc3 controller
> failing to initialize if probed after clk_disable_unused is called, for
> instance when the driver is built as a module.
>
> To fix this, switch to the clk_bulk API to handle both cfg_ahb and ref
> clocks at the proper places.
>
> Note that the cfg_ahb clock is currently not used by any device tree
> instantiation of the PHY. Work needs to be done separately to fix this.
>
> Link: https://lore.kernel.org/linux-arm-msm/ZEqvy+khHeTkC2hf@fedora/
> Fixes: 51e8114f80d0 ("phy: qcom-snps: Add SNPS USB PHY driver for QCOM based SOCs")
> Signed-off-by: Adrien Thierry <athierry at redhat.com>
> ---
> drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c | 67 ++++++++++++++-----
> 1 file changed, 49 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
> index 6c237f3cc66d..ce1d2f8b568a 100644
> --- a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
> +++ b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
> @@ -110,11 +110,13 @@ struct phy_override_seq {
> /**
> * struct qcom_snps_hsphy - snps hs phy attributes
> *
> + * @dev: device structure
> + *
> * @phy: generic phy
> * @base: iomapped memory space for snps hs phy
> *
> - * @cfg_ahb_clk: AHB2PHY interface clock
> - * @ref_clk: phy reference clock
> + * @num_clks: number of clocks
> + * @clks: array of clocks
> * @phy_reset: phy reset control
> * @vregs: regulator supplies bulk data
> * @phy_initialized: if PHY has been initialized correctly
> @@ -122,11 +124,13 @@ struct phy_override_seq {
> * @update_seq_cfg: tuning parameters for phy init
> */
> struct qcom_snps_hsphy {
> + struct device *dev;
> +
> struct phy *phy;
> void __iomem *base;
>
> - struct clk *cfg_ahb_clk;
> - struct clk *ref_clk;
> + int num_clks;
> + struct clk_bulk_data *clks;
> struct reset_control *phy_reset;
> struct regulator_bulk_data vregs[SNPS_HS_NUM_VREGS];
>
> @@ -135,6 +139,32 @@ struct qcom_snps_hsphy {
> struct phy_override_seq update_seq_cfg[NUM_HSPHY_TUNING_PARAMS];
> };
>
> +static int qcom_snps_hsphy_clk_init(struct qcom_snps_hsphy *hsphy)
> +{
> + struct device *dev = hsphy->dev;
> +
> + hsphy->num_clks = 2;
> + hsphy->clks = devm_kcalloc(dev, hsphy->num_clks, sizeof(*hsphy->clks), GFP_KERNEL);
> + if (!hsphy->clks)
> + return -ENOMEM;
> +
> + /*
> + * HACK: For cfg_ahb clock, use devm_clk_get_optional() because currently no device
> + * tree instantiation of the PHY is using the clock. This needs to be fixed in order
> + * for this code to be able to use devm_clk_bulk_get().
> + */
> + hsphy->clks[0].id = "cfg_ahb";
> + hsphy->clks[0].clk = devm_clk_get_optional(dev, "cfg_ahb");
Hm, maybe you could first check if we can get this clock
properly (!IS_ERR_OR_NULL) and then allocate the second
slot..
> +
> + hsphy->clks[1].id = "ref";
> + hsphy->clks[1].clk = devm_clk_get(dev, "ref");
> + if (IS_ERR(hsphy->clks[1].clk))
> + return dev_err_probe(dev, PTR_ERR(hsphy->clks[1].clk),
> + "failed to get ref clk\n");
> +
> + return 0;
> +}
> +
> static inline void qcom_snps_hsphy_write_mask(void __iomem *base, u32 offset,
> u32 mask, u32 val)
> {
> @@ -165,7 +195,7 @@ static int qcom_snps_hsphy_suspend(struct qcom_snps_hsphy *hsphy)
> 0, USB2_AUTO_RESUME);
> }
>
> - clk_disable_unprepare(hsphy->cfg_ahb_clk);
> + clk_bulk_disable_unprepare(hsphy->num_clks, hsphy->clks);
> return 0;
> }
>
> @@ -175,9 +205,9 @@ static int qcom_snps_hsphy_resume(struct qcom_snps_hsphy *hsphy)
>
> dev_dbg(&hsphy->phy->dev, "Resume QCOM SNPS PHY, mode\n");
>
> - ret = clk_prepare_enable(hsphy->cfg_ahb_clk);
> + ret = clk_bulk_prepare_enable(hsphy->num_clks, hsphy->clks);
Aren't you dereferencing NULL if the optional clock is absent?
Konrad
> if (ret) {
> - dev_err(&hsphy->phy->dev, "failed to enable cfg ahb clock\n");
> + dev_err(&hsphy->phy->dev, "failed to enable clocks\n");
> return ret;
> }
>
> @@ -374,16 +404,16 @@ static int qcom_snps_hsphy_init(struct phy *phy)
> if (ret)
> return ret;
>
> - ret = clk_prepare_enable(hsphy->cfg_ahb_clk);
> + ret = clk_bulk_prepare_enable(hsphy->num_clks, hsphy->clks);
> if (ret) {
> - dev_err(&phy->dev, "failed to enable cfg ahb clock, %d\n", ret);
> + dev_err(&phy->dev, "failed to enable clocks, %d\n", ret);
> goto poweroff_phy;
> }
>
> ret = reset_control_assert(hsphy->phy_reset);
> if (ret) {
> dev_err(&phy->dev, "failed to assert phy_reset, %d\n", ret);
> - goto disable_ahb_clk;
> + goto disable_clks;
> }
>
> usleep_range(100, 150);
> @@ -391,7 +421,7 @@ static int qcom_snps_hsphy_init(struct phy *phy)
> ret = reset_control_deassert(hsphy->phy_reset);
> if (ret) {
> dev_err(&phy->dev, "failed to de-assert phy_reset, %d\n", ret);
> - goto disable_ahb_clk;
> + goto disable_clks;
> }
>
> qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_CFG0,
> @@ -448,8 +478,8 @@ static int qcom_snps_hsphy_init(struct phy *phy)
>
> return 0;
>
> -disable_ahb_clk:
> - clk_disable_unprepare(hsphy->cfg_ahb_clk);
> +disable_clks:
> + clk_bulk_disable_unprepare(hsphy->num_clks, hsphy->clks);
> poweroff_phy:
> regulator_bulk_disable(ARRAY_SIZE(hsphy->vregs), hsphy->vregs);
>
> @@ -461,7 +491,7 @@ static int qcom_snps_hsphy_exit(struct phy *phy)
> struct qcom_snps_hsphy *hsphy = phy_get_drvdata(phy);
>
> reset_control_assert(hsphy->phy_reset);
> - clk_disable_unprepare(hsphy->cfg_ahb_clk);
> + clk_bulk_disable_unprepare(hsphy->num_clks, hsphy->clks);
> regulator_bulk_disable(ARRAY_SIZE(hsphy->vregs), hsphy->vregs);
> hsphy->phy_initialized = false;
>
> @@ -554,14 +584,15 @@ static int qcom_snps_hsphy_probe(struct platform_device *pdev)
> if (!hsphy)
> return -ENOMEM;
>
> + hsphy->dev = dev;
> +
> hsphy->base = devm_platform_ioremap_resource(pdev, 0);
> if (IS_ERR(hsphy->base))
> return PTR_ERR(hsphy->base);
>
> - hsphy->ref_clk = devm_clk_get(dev, "ref");
> - if (IS_ERR(hsphy->ref_clk))
> - return dev_err_probe(dev, PTR_ERR(hsphy->ref_clk),
> - "failed to get ref clk\n");
> + ret = qcom_snps_hsphy_clk_init(hsphy);
> + if (ret)
> + return dev_err_probe(dev, ret, "failed to initialize clocks\n");
>
> hsphy->phy_reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> if (IS_ERR(hsphy->phy_reset)) {
More information about the linux-phy
mailing list