[PATCH v6 3/8] clk: qcom: dispcc-sm8250: use runtime PM for the clock controller

[Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>]

On sm8250 dispcc and videocc registers are powered up by the MMCX power
domain. Use runtime PM calls to make sure that required power domain is
powered on while we access clock controller's registers.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
 drivers/clk/qcom/dispcc-sm8250.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/qcom/dispcc-sm8250.c b/drivers/clk/qcom/dispcc-sm8250.c
index 601c7c0ba483..108dd1249b6a 100644
--- a/drivers/clk/qcom/dispcc-sm8250.c
+++ b/drivers/clk/qcom/dispcc-sm8250.c
@@ -6,6 +6,7 @@
 #include <linux/clk-provider.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/reset-controller.h>
 
@@ -1226,13 +1227,31 @@ static const struct of_device_id disp_cc_sm8250_match_table[] = {
 };
 MODULE_DEVICE_TABLE(of, disp_cc_sm8250_match_table);
 
+static void disp_cc_sm8250_pm_runtime_disable(void *data)
+{
+	pm_runtime_disable(data);
+}
+
 static int disp_cc_sm8250_probe(struct platform_device *pdev)
 {
 	struct regmap *regmap;
+	int ret;
+
+	pm_runtime_enable(&pdev->dev);
+
+	ret = devm_add_action_or_reset(&pdev->dev, disp_cc_sm8250_pm_runtime_disable, &pdev->dev);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret)
+		return ret;
 
 	regmap = qcom_cc_map(pdev, &disp_cc_sm8250_desc);
-	if (IS_ERR(regmap))
+	if (IS_ERR(regmap)) {
+		pm_runtime_put(&pdev->dev);
 		return PTR_ERR(regmap);
+	}
 
 	/* note: trion == lucid, except for the prepare() op */
 	BUILD_BUG_ON(CLK_ALPHA_PLL_TYPE_TRION != CLK_ALPHA_PLL_TYPE_LUCID);
@@ -1257,7 +1276,11 @@ static int disp_cc_sm8250_probe(struct platform_device *pdev)
 	/* DISP_CC_XO_CLK always-on */
 	regmap_update_bits(regmap, 0x605c, BIT(0), BIT(0));
 
-	return qcom_cc_really_probe(pdev, &disp_cc_sm8250_desc, regmap);
+	ret = qcom_cc_really_probe(pdev, &disp_cc_sm8250_desc, regmap);
+
+	pm_runtime_put(&pdev->dev);
+
+	return ret;
 }
 
 static struct platform_driver disp_cc_sm8250_driver = {
-- 
2.30.2