[PATCH v4 3/6] ASoC: audio-graph-card: Support setting component plls and sysclks

[Richard Fitzgerald]

Some codecs need plls and/or sysclks to be configured using the
snd_soc_component_set_[sysclk|pll] functions. These drivers cannot
necessarily be converted to use the clock framework. If the codec is on
a I2C/SPI bus, a nested clk_get would be needed to enable the bus clock.
But the clock framework does not support nested operations and this would
deadlock.

This patch adds new dt properties that list phandles of components with
the pll/sysclk settings to be applied. Multiple settings can be given for
the same phandle to allow for components with multiple clocks and plls.
The plls and sysclks are enabled when the card bias level moves to STANDBY
and disabled when it moves to OFF.

The implementation does not attempt to handle specifying complex clock
ordering interdependencies between components. The plls and sysclks are
applied to a component as it is passed to the card set_bias_level/
set_bias_level_post callbacks. It follows from this that the order
components are configured is the order that they are passed to those
callbacks.

Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
---
 include/sound/simple_card_utils.h     |  25 +++
 sound/soc/generic/audio-graph-card.c  |  13 ++
 sound/soc/generic/simple-card-utils.c | 238 ++++++++++++++++++++++++++
 3 files changed, 276 insertions(+)

diff --git a/include/sound/simple_card_utils.h b/include/sound/simple_card_utils.h
index ba4a3e1897b9..1f755250f9c7 100644
--- a/include/sound/simple_card_utils.h
+++ b/include/sound/simple_card_utils.h
@@ -38,6 +38,16 @@ struct asoc_simple_jack {
 	struct snd_soc_jack_gpio gpio;
 };
 
+struct asoc_simple_sysclk_pll {
+	struct device_node *node;
+	struct clk *clk;
+	int id;
+	int source;
+	unsigned int freq_out;
+	int dir;
+	bool enabled;
+};
+
 struct asoc_simple_priv {
 	struct snd_soc_card snd_card;
 	struct simple_dai_props {
@@ -59,6 +69,11 @@ struct asoc_simple_priv {
 	const struct snd_soc_ops *ops;
 	unsigned int dpcm_selectable:1;
 	unsigned int force_dpcm:1;
+
+	struct asoc_simple_sysclk_pll *sysclks;
+	int num_sysclks;
+	struct asoc_simple_sysclk_pll *plls;
+	int num_plls;
 };
 #define simple_priv_to_card(priv)	(&(priv)->snd_card)
 #define simple_priv_to_props(priv, i)	((priv)->dai_props + (i))
@@ -97,6 +112,14 @@ void asoc_simple_shutdown(struct snd_pcm_substream *substream);
 int asoc_simple_hw_params(struct snd_pcm_substream *substream,
 			  struct snd_pcm_hw_params *params);
 int asoc_simple_dai_init(struct snd_soc_pcm_runtime *rtd);
+
+int asoc_simple_set_bias_level(struct snd_soc_card *card,
+			       struct snd_soc_dapm_context *dapm,
+			       enum snd_soc_bias_level level);
+int asoc_simple_set_bias_level_post(struct snd_soc_card *card,
+				    struct snd_soc_dapm_context *dapm,
+				    enum snd_soc_bias_level level);
+
 int asoc_simple_be_hw_params_fixup(struct snd_soc_pcm_runtime *rtd,
 				   struct snd_pcm_hw_params *params);
 
@@ -131,6 +154,8 @@ int asoc_simple_parse_widgets(struct snd_soc_card *card,
 				      char *prefix);
 int asoc_simple_parse_pin_switches(struct snd_soc_card *card,
 				   char *prefix);
+int asoc_simple_parse_sysclks(struct asoc_simple_priv *priv, char *prefix);
+int asoc_simple_parse_plls(struct asoc_simple_priv *priv, char *prefix);
 
 int asoc_simple_init_jack(struct snd_soc_card *card,
 			       struct asoc_simple_jack *sjack,
diff --git a/sound/soc/generic/audio-graph-card.c b/sound/soc/generic/audio-graph-card.c
index 16a04a678828..9aa15d5ecbd0 100644
--- a/sound/soc/generic/audio-graph-card.c
+++ b/sound/soc/generic/audio-graph-card.c
@@ -592,6 +592,19 @@ int graph_parse_of(struct asoc_simple_priv *priv, struct device *dev)
 
 	snd_soc_card_set_drvdata(card, priv);
 
+	ret = asoc_simple_parse_sysclks(priv, NULL);
+	if (ret < 0)
+		goto err;
+
+	ret = asoc_simple_parse_plls(priv, NULL);
+	if (ret < 0)
+		goto err;
+
+	if (priv->num_sysclks || priv->num_plls) {
+		card->set_bias_level = asoc_simple_set_bias_level;
+		card->set_bias_level_post = asoc_simple_set_bias_level_post;
+	}
+
 	asoc_simple_debug_info(priv);
 
 	ret = devm_snd_soc_register_card(dev, card);
diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
index 6cada4c1e283..a9b1849e328b 100644
--- a/sound/soc/generic/simple-card-utils.c
+++ b/sound/soc/generic/simple-card-utils.c
@@ -399,6 +399,162 @@ int asoc_simple_dai_init(struct snd_soc_pcm_runtime *rtd)
 }
 EXPORT_SYMBOL_GPL(asoc_simple_dai_init);
 
+static bool asoc_simple_node_is_component(struct snd_soc_component *component,
+					  struct device_node *node)
+{
+	struct device_node *comp_node;
+
+	comp_node = component->dev->of_node;
+	if (!comp_node && component->dev->parent)
+		comp_node = component->dev->parent->of_node;
+
+	return (comp_node == node);
+}
+
+int asoc_simple_set_bias_level(struct snd_soc_card *card,
+			       struct snd_soc_dapm_context *dapm,
+			       enum snd_soc_bias_level level)
+{
+	struct asoc_simple_priv *priv = snd_soc_card_get_drvdata(card);
+	struct snd_soc_component *component = dapm->component;
+	int i, ret;
+
+	if (!component)
+		return 0;
+
+	switch (level) {
+	case SND_SOC_BIAS_STANDBY:
+		if (dapm->bias_level != SND_SOC_BIAS_OFF)
+			break;
+
+		/*
+		 * A component's PLLs normally supply its SYSCLKs so enable
+		 * the PLLs first.
+		 */
+		for (i = 0; i < priv->num_plls; ++i) {
+			if (!asoc_simple_node_is_component(component, priv->plls[i].node))
+				continue;
+
+			ret = clk_prepare_enable(priv->plls[i].clk);
+			if (ret) {
+				dev_err(card->dev,
+					"(%s) failed to enable pll %d parent clock: %d\n",
+					component->name, priv->plls[i].id, ret);
+				return ret;
+			}
+
+			ret = snd_soc_component_set_pll(component,
+							priv->plls[i].id,
+							priv->plls[i].source,
+							clk_get_rate(priv->plls[i].clk),
+							priv->plls[i].freq_out);
+			if (ret) {
+				dev_err(card->dev, "(%s) failed to set pll %d: %d\n",
+					component->name, priv->plls[i].id, ret);
+
+				clk_disable_unprepare(priv->plls[i].clk);
+				return ret;
+			}
+
+			priv->plls[i].enabled = true;
+		}
+
+		for (i = 0; i < priv->num_sysclks; ++i) {
+			if (!asoc_simple_node_is_component(component, priv->sysclks[i].node))
+				continue;
+
+			ret = clk_prepare_enable(priv->sysclks[i].clk);
+			if (ret) {
+				dev_err(card->dev,
+					"(%s) failed to enable sysclk %d parent clock: %d\n",
+					component->name, priv->sysclks[i].id, ret);
+				return ret;
+			}
+
+			ret = snd_soc_component_set_sysclk(component,
+							   priv->sysclks[i].id,
+							   priv->sysclks[i].source,
+							   clk_get_rate(priv->sysclks[i].clk),
+							   priv->sysclks[i].dir);
+			if (ret) {
+				dev_err(card->dev, "(%s) failed to set sysclk %d: %d\n",
+					component->name, priv->sysclks[i].id, ret);
+
+				clk_disable_unprepare(priv->sysclks[i].clk);
+				return ret;
+			}
+
+			priv->sysclks[i].enabled = true;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(asoc_simple_set_bias_level);
+
+int asoc_simple_set_bias_level_post(struct snd_soc_card *card,
+				    struct snd_soc_dapm_context *dapm,
+				    enum snd_soc_bias_level level)
+{
+	struct asoc_simple_priv *priv = snd_soc_card_get_drvdata(card);
+	struct snd_soc_component *component = dapm->component;
+	int i, ret;
+
+	if (!component)
+		goto out;
+
+	switch (level) {
+	case SND_SOC_BIAS_OFF:
+		for (i = 0; i < priv->num_sysclks; ++i) {
+			if (!asoc_simple_node_is_component(component, priv->sysclks[i].node))
+				continue;
+
+			if (!priv->sysclks[i].enabled)
+				continue;
+
+			ret = snd_soc_component_set_sysclk(component,
+							   priv->sysclks[i].id,
+							   0,
+							   0,
+							   priv->sysclks[i].dir);
+			if (ret)
+				dev_warn(card->dev, "(%s) failed to disable sysclk %d: %d\n",
+					 component->name, priv->sysclks[i].id, ret);
+
+			clk_disable_unprepare(priv->sysclks[i].clk);
+			priv->sysclks[i].enabled = false;
+		}
+
+		for (i = 0; i < priv->num_plls; ++i) {
+			if (!asoc_simple_node_is_component(component, priv->plls[i].node))
+				continue;
+
+			if (!priv->plls[i].enabled)
+				continue;
+
+			ret = snd_soc_component_set_pll(component, priv->plls[i].id, 0, 0, 0);
+			if (ret)
+				dev_warn(card->dev, "(%s) failed to disable pll %d: %d\n",
+					 component->name, priv->plls[i].id, ret);
+
+			clk_disable_unprepare(priv->plls[i].clk);
+			priv->plls[i].enabled = false;
+		}
+		break;
+	default:
+		break;
+	}
+
+out:
+	dapm->bias_level = level;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(asoc_simple_set_bias_level_post);
+
 void asoc_simple_canonicalize_platform(struct snd_soc_dai_link *dai_link)
 {
 	/* Assumes platform == cpu */
@@ -433,6 +589,7 @@ EXPORT_SYMBOL_GPL(asoc_simple_canonicalize_cpu);
 
 int asoc_simple_clean_reference(struct snd_soc_card *card)
 {
+	struct asoc_simple_priv *priv = snd_soc_card_get_drvdata(card);
 	struct snd_soc_dai_link *dai_link;
 	int i;
 
@@ -440,6 +597,15 @@ int asoc_simple_clean_reference(struct snd_soc_card *card)
 		of_node_put(dai_link->cpus->of_node);
 		of_node_put(dai_link->codecs->of_node);
 	}
+
+	if (priv) {
+		for (i = 0; i < priv->num_sysclks; ++i)
+			of_node_put(priv->sysclks[i].node);
+
+		for (i = 0; i < priv->num_plls; ++i)
+			of_node_put(priv->plls[i].node);
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(asoc_simple_clean_reference);
@@ -538,6 +704,78 @@ int asoc_simple_parse_pin_switches(struct snd_soc_card *card,
 }
 EXPORT_SYMBOL_GPL(asoc_simple_parse_pin_switches);
 
+static int asoc_simple_parse_sysclks_plls(struct asoc_simple_priv *priv,
+					  char *prefix,
+					  char *prop_root_name,
+					  struct asoc_simple_sysclk_pll **out,
+					  int *out_count)
+{
+	struct device *dev = priv->snd_card.dev;
+	struct device_node *node = dev->of_node;
+	struct of_phandle_args args;
+	int n_elem, i, ret;
+	char prop[128];
+	char clocks_prop[128];
+	const char *src_clk_name;
+	struct clk *in_clk;
+
+	if (!prefix)
+		prefix = "";
+
+	snprintf(prop, sizeof(prop), "%s%s", prefix, prop_root_name);
+	snprintf(clocks_prop, sizeof(clocks_prop), "%s-clocks", prop);
+	n_elem = of_count_phandle_with_fixed_args(node, prop, 3);
+	if (n_elem == -ENOENT || n_elem == 0) {
+		return 0;
+	} else if (n_elem < 0) {
+		dev_err(dev, "Failed to parse %s: %d\n", prop, n_elem);
+		return n_elem;
+	}
+
+	*out = devm_kcalloc(dev, n_elem, sizeof(**out), GFP_KERNEL);
+	if (!*out)
+		return -ENOMEM;
+	*out_count = 0;
+
+	for (i = 0; i < n_elem; ++i) {
+		ret = of_property_read_string_index(node, clocks_prop, i, &src_clk_name);
+		if (ret < 0)
+			return ret;
+
+		in_clk = devm_clk_get(dev, src_clk_name);
+		if (IS_ERR(in_clk))
+			return PTR_ERR(in_clk);
+
+		ret = of_parse_phandle_with_fixed_args(node, prop, 3, i, &args);
+		if (ret < 0)
+			return ret;
+
+		(*out)[i].node		= args.np;
+		(*out)[i].clk		= in_clk;
+		(*out)[i].id		= args.args[0];
+		(*out)[i].source	= args.args[1];
+		(*out)[i].dir		= args.args[2]; /* for sysclks */
+		(*out)[i].freq_out	= args.args[2]; /* for plls */
+		++*out_count;
+	}
+
+	return 0;
+}
+
+int asoc_simple_parse_sysclks(struct asoc_simple_priv *priv, char *prefix)
+{
+	return asoc_simple_parse_sysclks_plls(priv, prefix, "sysclks",
+					      &priv->sysclks, &priv->num_sysclks);
+}
+EXPORT_SYMBOL_GPL(asoc_simple_parse_sysclks);
+
+int asoc_simple_parse_plls(struct asoc_simple_priv *priv, char *prefix)
+{
+	return asoc_simple_parse_sysclks_plls(priv, prefix, "plls",
+					      &priv->plls, &priv->num_plls);
+}
+EXPORT_SYMBOL_GPL(asoc_simple_parse_plls);
+
 int asoc_simple_init_jack(struct snd_soc_card *card,
 			  struct asoc_simple_jack *sjack,
 			  int is_hp, char *prefix,
-- 
2.20.1