[PATCH v4 12/19] ASoC: tegra: Add initial parent configuration for audio mclk

[Sowjanya Komatineni <skomatineni@nvidia.com>]

Tegra PMC clock clk_out_1 is dedicated for audio mclk from Tegra30
through Tegra210 and currently Tegra clock driver does initial parent
configuration for audio mclk "clk_out_1" and enables them by default.

With the move of Tera PMC clocks from clock driver to Tegra PMC
driver, initial parent configuration for audio clocks are through
the device tree using assigned-clock-parents property.

Default clock parents can be specified in device tree using
assigned-clocks and assigned-clock-parents and there is no need
to have clock driver do parent configuration and enable audio related
clocks.

This patch has implementation of doing initial parent confgiuration
in audio driver when default parent configuration is not specified
in the device tree using assigned-clock properties.

This patch configures PLLA_OUT0 as parent to extern1 and extern1
as parent to clk_out_1 and uses clk_out_1 as cdev1 clock to allow
mclk control from this driver.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
 sound/soc/tegra/tegra_asoc_utils.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/sound/soc/tegra/tegra_asoc_utils.c b/sound/soc/tegra/tegra_asoc_utils.c
index 38535962029c..fe9ca8acd0fb 100644
--- a/sound/soc/tegra/tegra_asoc_utils.c
+++ b/sound/soc/tegra/tegra_asoc_utils.c
@@ -158,6 +158,7 @@ EXPORT_SYMBOL_GPL(tegra_asoc_utils_set_ac97_rate);
 int tegra_asoc_utils_init(struct tegra_asoc_utils_data *data,
 			  struct device *dev)
 {
+	struct clk *clk_out_1, *clk_extern1;
 	int ret;
 
 	data->dev = dev;
@@ -193,6 +194,41 @@ int tegra_asoc_utils_init(struct tegra_asoc_utils_data *data,
 		return PTR_ERR(data->clk_cdev1);
 	}
 
+	/*
+	 * If clock parents are not set in DT, configure here to use clk_out_1
+	 * as mclk and extern1 as parent for Tegra30 and higher.
+	 */
+	if (!of_find_property(dev->of_node, "assigned-clock-parents", NULL) &&
+	    data->soc > TEGRA_ASOC_UTILS_SOC_TEGRA20) {
+		clk_extern1 = devm_clk_get(dev, "extern1");
+		if (IS_ERR(clk_extern1)) {
+			dev_err(data->dev, "Can't retrieve clk extern1\n");
+			return PTR_ERR(clk_extern1);
+		}
+
+		ret = clk_set_parent(clk_extern1, data->clk_pll_a_out0);
+		if (ret < 0) {
+			dev_err(data->dev,
+				"Set parent failed for clk extern1\n");
+			return ret;
+		}
+
+		clk_out_1 = devm_clk_get(dev, "clk_out_1");
+		if (IS_ERR(clk_out_1)) {
+			dev_err(data->dev, "Can't retrieve clk clk_out_1\n");
+			return PTR_ERR(clk_out_1);
+		}
+
+		ret = clk_set_parent(clk_out_1, clk_extern1);
+		if (ret < 0) {
+			dev_err(data->dev,
+				"Set parent failed for clk_out_1\n");
+			return ret;
+		}
+
+		data->clk_cdev1 = clk_out_1;
+	}
+
 	ret = tegra_asoc_utils_set_rate(data, 44100, 256 * 44100);
 
 	return ret;
-- 
2.7.4