[PATCH 2/5] clk: qcom: apcs-msm8916: get parent clock names from DT

[Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>]

Allow accessing the parent clock names required for the driver
operation by using the device tree node.

This permits extending the driver to other platforms without having to
modify its source code.

For backwards compatibility leave previous values as default.

Co-developed-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 drivers/clk/qcom/apcs-msm8916.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/qcom/apcs-msm8916.c b/drivers/clk/qcom/apcs-msm8916.c
index a6c89a310b18..dd82eb1e5202 100644
--- a/drivers/clk/qcom/apcs-msm8916.c
+++ b/drivers/clk/qcom/apcs-msm8916.c
@@ -19,7 +19,7 @@
 
 static const u32 gpll0_a53cc_map[] = { 4, 5 };
 
-static const char * const gpll0_a53cc[] = {
+static const char *gpll0_a53cc[] = {
 	"gpll0_vote",
 	"a53pll",
 };
@@ -50,6 +50,8 @@ static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
 	struct regmap *regmap;
 	struct clk_init_data init = { };
 	int ret = -ENODEV;
+	const char *parents[2];
+	int pll_index = 0;
 
 	regmap = dev_get_regmap(parent, NULL);
 	if (!regmap) {
@@ -61,6 +63,16 @@ static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
 	if (!a53cc)
 		return -ENOMEM;
 
+	/* legacy bindings only defined the pll parent clock (index = 0) with no
+	 * name; when both of the parents are specified in the bindings, the
+	 * pll is the second one (index = 1).
+	 */
+	if (of_clk_parent_fill(parent->of_node, parents, 2) == 2) {
+		gpll0_a53cc[0] = parents[0];
+		gpll0_a53cc[1] = parents[1];
+		pll_index = 1;
+	}
+
 	init.name = "a53mux";
 	init.parent_names = gpll0_a53cc;
 	init.num_parents = ARRAY_SIZE(gpll0_a53cc);
@@ -76,10 +88,11 @@ static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
 	a53cc->src_shift = 8;
 	a53cc->parent_map = gpll0_a53cc_map;
 
-	a53cc->pclk = devm_clk_get(parent, NULL);
+	a53cc->pclk = of_clk_get(parent->of_node, pll_index);
 	if (IS_ERR(a53cc->pclk)) {
 		ret = PTR_ERR(a53cc->pclk);
-		dev_err(dev, "failed to get clk: %d\n", ret);
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "failed to get clk: %d\n", ret);
 		return ret;
 	}
 
@@ -87,6 +100,7 @@ static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
 	ret = clk_notifier_register(a53cc->pclk, &a53cc->clk_nb);
 	if (ret) {
 		dev_err(dev, "failed to register clock notifier: %d\n", ret);
+		clk_put(a53cc->pclk);
 		return ret;
 	}
 
@@ -109,6 +123,8 @@ static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
 
 err:
 	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
+	clk_put(a53cc->pclk);
+
 	return ret;
 }
 
@@ -117,6 +133,7 @@ static int qcom_apcs_msm8916_clk_remove(struct platform_device *pdev)
 	struct clk_regmap_mux_div *a53cc = platform_get_drvdata(pdev);
 
 	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
+	clk_put(a53cc->pclk);
 
 	return 0;
 }
-- 
2.22.0