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

From: Douglas Anderson
Date: Wed Oct 14 2020 - 21:30:39 EST


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