[PATCH v0] LPASSCC: Configure the PLL in case lost for SC7180

[PATCH v0] LPASSCC: Configure the PLL in case lost for SC7180

[Taniya Das]

In the case where the LPASSCC PLL loses the PLL configuration it would fail
to lock. Thus allow reconfigure the PLL from pm_resume.

Taniya Das (1):
  clk: qcom: lpasscc: Re-configure the PLL in case lost

 drivers/clk/qcom/lpasscorecc-sc7180.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

--
Qualcomm INDIA, on behalf of Qualcomm Innovation Center, Inc.is a member
of the Code Aurora Forum, hosted by the  Linux Foundation.

[PATCH v0] clk: qcom: lpasscc: Re-configure the PLL in case lost

[Taniya Das]

In the case where the PLL configuration is lost, then the pm runtime
resume will reconfigure before usage.

Fixes: edab812d802d ("clk: qcom: lpass: Add support for LPASS clock controller for SC7180")
Signed-off-by: Taniya Das <tdas@codeaurora.org>
---
 drivers/clk/qcom/lpasscorecc-sc7180.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/clk/qcom/lpasscorecc-sc7180.c b/drivers/clk/qcom/lpasscorecc-sc7180.c
index 228d08f..5804a93 100644
--- a/drivers/clk/qcom/lpasscorecc-sc7180.c
+++ b/drivers/clk/qcom/lpasscorecc-sc7180.c
@@ -356,6 +356,25 @@ static const struct qcom_cc_desc lpass_audio_hm_sc7180_desc = {
 	.num_gdscs = ARRAY_SIZE(lpass_audio_hm_sc7180_gdscs),
 };

+static int lpass_core_cc_pm_clk_resume(struct device *dev)
+{
+	struct regmap *regmap = dev_get_drvdata(dev);
+	int l_val;
+
+	pm_clk_resume(dev);
+
+	/* Read PLL_L_VAL */
+	regmap_read(regmap, 0x1004, &l_val);
+	if (!l_val)
+		clk_fabia_pll_configure(&lpass_lpaaudio_dig_pll, regmap,
+				&lpass_lpaaudio_dig_pll_config);
+	return 0;
+}
+
+static const struct dev_pm_ops lpass_core_pm_ops = {
+	SET_RUNTIME_PM_OPS(pm_clk_suspend, lpass_core_cc_pm_clk_resume, NULL)
+};
+
 static int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
 {
 	const struct qcom_cc_desc *desc;
@@ -386,6 +405,9 @@ static int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
 	clk_fabia_pll_configure(&lpass_lpaaudio_dig_pll, regmap,
 				&lpass_lpaaudio_dig_pll_config);

+	pdev->dev.driver->pm = &lpass_core_pm_ops;
+	dev_set_drvdata(&pdev->dev, regmap);
+
 	return qcom_cc_really_probe(pdev, &lpass_core_cc_sc7180_desc, regmap);
 }

--
Qualcomm INDIA, on behalf of Qualcomm Innovation Center, Inc.is a member
of the Code Aurora Forum, hosted by the  Linux Foundation.

Re: [PATCH v0] clk: qcom: lpasscc: Re-configure the PLL in case lost

[Doug Anderson]

Hi,

On Tue, Oct 13, 2020 at 11:33 AM Taniya Das <tdas@codeaurora.org> wrote:
>
> In the case where the PLL configuration is lost, then the pm runtime
> resume will reconfigure before usage.
>
> Fixes: edab812d802d ("clk: qcom: lpass: Add support for LPASS clock controller for SC7180")
> Signed-off-by: Taniya Das <tdas@codeaurora.org>
> ---
>  drivers/clk/qcom/lpasscorecc-sc7180.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
>
> diff --git a/drivers/clk/qcom/lpasscorecc-sc7180.c b/drivers/clk/qcom/lpasscorecc-sc7180.c
> index 228d08f..5804a93 100644
> --- a/drivers/clk/qcom/lpasscorecc-sc7180.c
> +++ b/drivers/clk/qcom/lpasscorecc-sc7180.c
> @@ -356,6 +356,25 @@ static const struct qcom_cc_desc lpass_audio_hm_sc7180_desc = {
>         .num_gdscs = ARRAY_SIZE(lpass_audio_hm_sc7180_gdscs),
>  };
>
> +static int lpass_core_cc_pm_clk_resume(struct device *dev)
> +{
> +       struct regmap *regmap = dev_get_drvdata(dev);
> +       int l_val;

nit: technically "unsigned int" to match what regmap_read takes.

> +
> +       pm_clk_resume(dev);

Even though pm_clk_resume() doesn't currently return any errors, it
would be good form to check.  AKA:

ret = pm_clk_resume(dev);
if (ret)
  return ret;


> +       /* Read PLL_L_VAL */
> +       regmap_read(regmap, 0x1004, &l_val);
> +       if (!l_val)
> +               clk_fabia_pll_configure(&lpass_lpaaudio_dig_pll, regmap,
> +                               &lpass_lpaaudio_dig_pll_config);
> +       return 0;
> +}
> +
> +static const struct dev_pm_ops lpass_core_pm_ops = {
> +       SET_RUNTIME_PM_OPS(pm_clk_suspend, lpass_core_cc_pm_clk_resume, NULL)
> +};
> +
>  static int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
>  {
>         const struct qcom_cc_desc *desc;
> @@ -386,6 +405,9 @@ static int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
>         clk_fabia_pll_configure(&lpass_lpaaudio_dig_pll, regmap,
>                                 &lpass_lpaaudio_dig_pll_config);
>
> +       pdev->dev.driver->pm = &lpass_core_pm_ops;
> +       dev_set_drvdata(&pdev->dev, regmap);

I'm kinda confused.  Why not just change "lpass_core_cc_pm_ops"?  Then
you can get rid of the above two lines of code and get rid of the
whole "lpass_core_pm_ops" structure?


-Doug