[PATCH v4 3/3] clk: qcom: lpasscc-sc7180: Re-configure the PLL in case lost

[Douglas Anderson]

From: Taniya Das <tdas@xxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxx>
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---

Changes in v4:
- Put regmap names in "static const char *" globals.

Changes in v3:
- Now based on a series which disentangles the two clock devices.
- Use dev_get_regmap().
- Better comment about reading PLL_L_VAL.

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 | 28 ++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/qcom/lpasscorecc-sc7180.c b/drivers/clk/qcom/lpasscorecc-sc7180.c
index 4ed766ca08bb..d7586858760c 100644
--- a/drivers/clk/qcom/lpasscorecc-sc7180.c
+++ b/drivers/clk/qcom/lpasscorecc-sc7180.c
@@ -21,6 +21,9 @@
 #include "common.h"
 #include "gdsc.h"
 
+static const char *lpass_audio_cc_regmap_name = "lpass_audio_cc";
+static const char *lpass_core_cc_regmap_name = "lpass_core_cc";
+
 enum {
 	P_BI_TCXO,
 	P_LPASS_LPAAUDIO_DIG_PLL_OUT_ODD,
@@ -388,6 +391,25 @@ static int lpass_create_pm_clks(struct platform_device *pdev)
 	return ret;
 }
 
+static int lpass_core_cc_pm_clk_resume(struct device *dev)
+{
+	struct regmap *regmap = dev_get_regmap(dev, lpass_core_cc_regmap_name);
+	unsigned int l_val;
+	int ret;
+
+	ret = pm_clk_resume(dev);
+	if (ret)
+		return ret;
+
+	/* If PLL_L_VAL was cleared then we should re-init the whole PLL */
+	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;
@@ -398,13 +420,13 @@ static int lpass_core_cc_sc7180_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	lpass_core_cc_sc7180_regmap_config.name = "lpass_audio_cc";
+	lpass_core_cc_sc7180_regmap_config.name = lpass_audio_cc_regmap_name;
 	desc = &lpass_audio_hm_sc7180_desc;
 	ret = qcom_cc_probe_by_index(pdev, 1, desc);
 	if (ret)
 		return ret;
 
-	lpass_core_cc_sc7180_regmap_config.name = "lpass_core_cc";
+	lpass_core_cc_sc7180_regmap_config.name = lpass_core_cc_regmap_name;
 	regmap = qcom_cc_map(pdev, &lpass_core_cc_sc7180_desc);
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);
@@ -457,7 +479,7 @@ static const struct of_device_id lpass_core_cc_sc7180_match_table[] = {
 MODULE_DEVICE_TABLE(of, lpass_core_cc_sc7180_match_table);
 
 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