[PATCH v2] clk: qcom: lpasscc: Re-configure the PLL in case lost

[Douglas Anderson <dianders@chromium.org>]

From: Taniya Das <tdas@codeaurora.org>

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>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
I took the liberty of fixing my own nits that I had with Taniya's
patch, AKA:

https://lore.kernel.org/r/1602614008-2421-2-git-send-email-tdas@codeaurora.org

Changes in v2:
- Don't needlessly have a 2nd copy of dev_pm_ops and jam it in.
- Check the return value of pm_clk_resume()
- l_val should be unsigned int.

 drivers/clk/qcom/lpasscorecc-sc7180.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/qcom/lpasscorecc-sc7180.c b/drivers/clk/qcom/lpasscorecc-sc7180.c
index 228d08f5d26f..ee23eb5b9bf2 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);
+	unsigned int l_val;
+	int ret;
+
+	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 int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
 {
 	const struct qcom_cc_desc *desc;
@@ -373,6 +392,8 @@ static int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);
 
+	dev_set_drvdata(&pdev->dev, regmap);
+
 	/*
 	 * Keep the CLK always-ON
 	 * LPASS_AUDIO_CORE_SYSNOC_SWAY_CORE_CLK
@@ -449,7 +470,7 @@ static int lpass_core_sc7180_probe(struct platform_device *pdev)
 }
 
 static const struct dev_pm_ops lpass_core_cc_pm_ops = {
-	SET_RUNTIME_PM_OPS(pm_clk_suspend, pm_clk_resume, NULL)
+	SET_RUNTIME_PM_OPS(pm_clk_suspend, lpass_core_cc_pm_clk_resume, NULL)
 };
 
 static struct platform_driver lpass_core_cc_sc7180_driver = {
-- 
2.28.0.1011.ga647a8990f-goog