ASoC: tegra: add function to set ac97 rate

AC97 uses a fixed rate, unrelated to the sample rate. Add a function to
make the setup more trivial.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/tegra/tegra_asoc_utils.c

@@ -112,6 +112,59 @@ int tegra_asoc_utils_set_rate(struct tegra_asoc_utils_data *data, int srate,
 }
 EXPORT_SYMBOL_GPL(tegra_asoc_utils_set_rate);
 
+int tegra_asoc_utils_set_ac97_rate(struct tegra_asoc_utils_data *data)
+{
+	const int pll_rate = 73728000;
+	const int ac97_rate = 24576000;
+	int err;
+
+	clk_disable_unprepare(data->clk_cdev1);
+	clk_disable_unprepare(data->clk_pll_a_out0);
+	clk_disable_unprepare(data->clk_pll_a);
+
+	/*
+	 * AC97 rate is fixed at 24.576MHz and is used for both the host
+	 * controller and the external codec
+	 */
+	err = clk_set_rate(data->clk_pll_a, pll_rate);
+	if (err) {
+		dev_err(data->dev, "Can't set pll_a rate: %d\n", err);
+		return err;
+	}
+
+	err = clk_set_rate(data->clk_pll_a_out0, ac97_rate);
+	if (err) {
+		dev_err(data->dev, "Can't set pll_a_out0 rate: %d\n", err);
+		return err;
+	}
+
+	/* Don't set cdev1/extern1 rate; it's locked to pll_a_out0 */
+
+	err = clk_prepare_enable(data->clk_pll_a);
+	if (err) {
+		dev_err(data->dev, "Can't enable pll_a: %d\n", err);
+		return err;
+	}
+
+	err = clk_prepare_enable(data->clk_pll_a_out0);
+	if (err) {
+		dev_err(data->dev, "Can't enable pll_a_out0: %d\n", err);
+		return err;
+	}
+
+	err = clk_prepare_enable(data->clk_cdev1);
+	if (err) {
+		dev_err(data->dev, "Can't enable cdev1: %d\n", err);
+		return err;
+	}
+
+	data->set_baseclock = pll_rate;
+	data->set_mclk = ac97_rate;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra_asoc_utils_set_ac97_rate);
+
 int tegra_asoc_utils_init(struct tegra_asoc_utils_data *data,
 			  struct device *dev)
 {

sound/soc/tegra/tegra_asoc_utils.h

@@ -43,6 +43,7 @@ struct tegra_asoc_utils_data {
 
 int tegra_asoc_utils_set_rate(struct tegra_asoc_utils_data *data, int srate,
 			      int mclk);
+int tegra_asoc_utils_set_ac97_rate(struct tegra_asoc_utils_data *data);
 int tegra_asoc_utils_init(struct tegra_asoc_utils_data *data,
 			  struct device *dev);
 void tegra_asoc_utils_fini(struct tegra_asoc_utils_data *data);