[PATCH v3 11/15] clk: qcom: gcc-qcm2290: Add runtime PM

[Konrad Dybcio <konrad.dybcio@linaro.org>]

The GCC block on QCM2290 is powered by the VDD_CX rail. We need to
ensure that CX is enabled to prevent unwanted power collapse and that
the reference is dropped when unused so that the system can enter a
firmware-managed lower power state.

Enable runtime PM to keep the power flowing only when necessary.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 drivers/clk/qcom/gcc-qcm2290.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/qcom/gcc-qcm2290.c b/drivers/clk/qcom/gcc-qcm2290.c
index cc1dd5fc6d32..0992da84a741 100644
--- a/drivers/clk/qcom/gcc-qcm2290.c
+++ b/drivers/clk/qcom/gcc-qcm2290.c
@@ -8,6 +8,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 
 #include <dt-bindings/clock/qcom,gcc-qcm2290.h>
@@ -2882,14 +2883,26 @@ static int gcc_qcm2290_probe(struct platform_device *pdev)
 	struct regmap *regmap;
 	int ret;
 
+	ret = devm_pm_runtime_enable(&pdev->dev);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret)
+		return ret;
+
 	regmap = qcom_cc_map(pdev, &gcc_qcm2290_desc);
-	if (IS_ERR(regmap))
+	if (IS_ERR(regmap)) {
+		pm_runtime_put(&pdev->dev);
 		return PTR_ERR(regmap);
+	}
 
 	ret = qcom_cc_register_rcg_dfs(regmap, gcc_dfs_clocks,
 				       ARRAY_SIZE(gcc_dfs_clocks));
-	if (ret)
+	if (ret) {
+		pm_runtime_put(&pdev->dev);
 		return ret;
+	}
 
 	clk_alpha_pll_configure(&gpll10, regmap, &gpll10_config);
 	clk_alpha_pll_configure(&gpll11, regmap, &gpll11_config);
@@ -2903,7 +2916,10 @@ static int gcc_qcm2290_probe(struct platform_device *pdev)
 	qcom_branch_set_clk_en(regmap, 0x36004); /* GCC_GPU_CFG_AHB_CLK */
 	qcom_branch_set_clk_en(regmap, 0x2b06c); /* GCC_SYS_NOC_CPUSS_AHB_CLK */
 
-	return qcom_cc_really_probe(pdev, &gcc_qcm2290_desc, regmap);
+	ret = qcom_cc_really_probe(pdev, &gcc_qcm2290_desc, regmap);
+	pm_runtime_put(&pdev->dev);
+
+	return ret;
 }
 
 static struct platform_driver gcc_qcm2290_driver = {

-- 
2.43.0