ASoC: Move IO abstraction to the component level

We currently have two very similar IO abstractions in ASoC, one for CODECs, the
other for platforms. Moving this to the component level will allow us to unify
those two. It will also enable us to move the standard kcontrol helpers as well
as DAPM support to the component level.

The new component level abstraction layer is primarily build around regmap.
There is a per component pointer for the regmap instance for the underlying
device. There are four new function snd_soc_component_read(),
snd_soc_component_write(), snd_soc_component_update_bits() and
snd_soc_component_update_bits_async(). They have the same signature as their
regmap counter-part and will internally forward the call one-to-one to regmap.
If the component it not using regmap it will fallback to using the custom IO
callbacks. This is done to be able to support drivers that haven't been
converted to regmap yet, but it is expected that this will eventually be removed
in the future once all component drivers have been converted to regmap.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 210 insertions, 112 deletions

diff --git a/sound/soc/soc-io.c b/sound/soc/soc-io.c
index dc0c09d2682a..ac64fd7252b2 100644
--- a/sound/soc/soc-io.c
+++ b/sound/soc/soc-io.c
@@ -19,24 +19,205 @@
 
 #include <trace/events/asoc.h>
 
-unsigned int snd_soc_read(struct snd_soc_codec *codec, unsigned int reg)
+/**
+ * snd_soc_component_read() - Read register value
+ * @component: Component to read from
+ * @reg: Register to read
+ * @val: Pointer to where the read value is stored
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+int snd_soc_component_read(struct snd_soc_component *component,
+	unsigned int reg, unsigned int *val)
+{
+	int ret;
+
+	if (component->regmap)
+		ret = regmap_read(component->regmap, reg, val);
+	else if (component->read)
+		ret = component->read(component, reg, val);
+	else
+		ret = -EIO;
+
+	dev_dbg(component->dev, "read %x => %x\n", reg, *val);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_read);
+
+/**
+ * snd_soc_component_write() - Write register value
+ * @component: Component to write to
+ * @reg: Register to write
+ * @val: Value to write to the register
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+int snd_soc_component_write(struct snd_soc_component *component,
+	unsigned int reg, unsigned int val)
 {
-	unsigned int ret;
+	dev_dbg(component->dev, "write %x = %x\n", reg, val);
 
-	ret = codec->read(codec, reg);
-	dev_dbg(codec->dev, "read %x => %x\n", reg, ret);
-	trace_snd_soc_reg_read(codec, reg, ret);
+	if (component->regmap)
+		return regmap_write(component->regmap, reg, val);
+	else if (component->write)
+		return component->write(component, reg, val);
+	else
+		return -EIO;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_write);
+
+static int snd_soc_component_update_bits_legacy(
+	struct snd_soc_component *component, unsigned int reg,
+	unsigned int mask, unsigned int val, bool *change)
+{
+	unsigned int old, new;
+	int ret;
+
+	if (!component->read || !component->write)
+		return -EIO;
+
+	mutex_lock(&component->io_mutex);
+
+	ret = component->read(component, reg, &old);
+	if (ret < 0)
+		goto out_unlock;
+
+	new = (old & ~mask) | (val & mask);
+	*change = old != new;
+	if (*change)
+		ret = component->write(component, reg, new);
+out_unlock:
+	mutex_unlock(&component->io_mutex);
 
 	return ret;
 }
+
+/**
+ * snd_soc_component_update_bits() - Perform read/modify/write cycle
+ * @component: Component to update
+ * @reg: Register to update
+ * @mask: Mask that specifies which bits to update
+ * @val: New value for the bits specified by mask
+ *
+ * Return: 1 if the operation was successful and the value of the register
+ * changed, 0 if the operation was successful, but the value did not change.
+ * Returns a negative error code otherwise.
+ */
+int snd_soc_component_update_bits(struct snd_soc_component *component,
+	unsigned int reg, unsigned int mask, unsigned int val)
+{
+	bool change;
+	int ret;
+
+	if (component->regmap)
+		ret = regmap_update_bits_check(component->regmap, reg, mask,
+			val, &change);
+	else
+		ret = snd_soc_component_update_bits_legacy(component, reg,
+			mask, val, &change);
+
+	if (ret < 0)
+		return ret;
+	return change;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_update_bits);
+
+/**
+ * snd_soc_component_update_bits_async() - Perform asynchronous
+ *  read/modify/write cycle
+ * @component: Component to update
+ * @reg: Register to update
+ * @mask: Mask that specifies which bits to update
+ * @val: New value for the bits specified by mask
+ *
+ * This function is similar to snd_soc_component_update_bits(), but the update
+ * operation is scheduled asynchronously. This means it may not be completed
+ * when the function returns. To make sure that all scheduled updates have been
+ * completed snd_soc_component_async_complete() must be called.
+ *
+ * Return: 1 if the operation was successful and the value of the register
+ * changed, 0 if the operation was successful, but the value did not change.
+ * Returns a negative error code otherwise.
+ */
+int snd_soc_component_update_bits_async(struct snd_soc_component *component,
+	unsigned int reg, unsigned int mask, unsigned int val)
+{
+	bool change;
+	int ret;
+
+	if (component->regmap)
+		ret = regmap_update_bits_check_async(component->regmap, reg,
+			mask, val, &change);
+	else
+		ret = snd_soc_component_update_bits_legacy(component, reg,
+			mask, val, &change);
+
+	if (ret < 0)
+		return ret;
+	return change;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_update_bits_async);
+
+/**
+ * snd_soc_component_async_complete() - Ensure asynchronous I/O has completed
+ * @component: Component for which to wait
+ *
+ * This function blocks until all asynchronous I/O which has previously been
+ * scheduled using snd_soc_component_update_bits_async() has completed.
+ */
+void snd_soc_component_async_complete(struct snd_soc_component *component)
+{
+	if (component->regmap)
+		regmap_async_complete(component->regmap);
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_async_complete);
+
+/**
+ * snd_soc_component_test_bits - Test register for change
+ * @component: component
+ * @reg: Register to test
+ * @mask: Mask that specifies which bits to test
+ * @value: Value to test against
+ *
+ * Tests a register with a new value and checks if the new value is
+ * different from the old value.
+ *
+ * Return: 1 for change, otherwise 0.
+ */
+int snd_soc_component_test_bits(struct snd_soc_component *component,
+	unsigned int reg, unsigned int mask, unsigned int value)
+{
+	unsigned int old, new;
+	int ret;
+
+	ret = snd_soc_component_read(component, reg, &old);
+	if (ret < 0)
+		return ret;
+	new = (old & ~mask) | value;
+	return old != new;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_test_bits);
+
+unsigned int snd_soc_read(struct snd_soc_codec *codec, unsigned int reg)
+{
+	unsigned int val;
+	int ret;
+
+	ret = snd_soc_component_read(&codec->component, reg, &val);
+	if (ret < 0)
+		return -1;
+	trace_snd_soc_reg_read(codec, reg, val);
+
+	return val;
+}
 EXPORT_SYMBOL_GPL(snd_soc_read);
 
 int snd_soc_write(struct snd_soc_codec *codec, unsigned int reg,
 	unsigned int val)
 {
-	dev_dbg(codec->dev, "write %x = %x\n", reg, val);
 	trace_snd_soc_reg_write(codec, reg, val);
-	return codec->write(codec, reg, val);
+	return snd_soc_component_write(&codec->component, reg, val);
 }
 EXPORT_SYMBOL_GPL(snd_soc_write);
 
@@ -54,29 +235,8 @@ EXPORT_SYMBOL_GPL(snd_soc_write);
 int snd_soc_update_bits(struct snd_soc_codec *codec, unsigned int reg,
 				unsigned int mask, unsigned int value)
 {
-	bool change;
-	unsigned int old, new;
-	int ret;
-
-	if (codec->using_regmap) {
-		ret = regmap_update_bits_check(codec->control_data, reg,
-					       mask, value, &change);
-	} else {
-		ret = snd_soc_read(codec, reg);
-		if (ret < 0)
-			return ret;
-
-		old = ret;
-		new = (old & ~mask) | (value & mask);
-		change = old != new;
-		if (change)
-			ret = snd_soc_write(codec, reg, new);
-	}
-
-	if (ret < 0)
-		return ret;
-
-	return change;
+	return snd_soc_component_update_bits(&codec->component, reg, mask,
+		value);
 }
 EXPORT_SYMBOL_GPL(snd_soc_update_bits);
 
@@ -95,13 +255,8 @@ int snd_soc_update_bits_locked(struct snd_soc_codec *codec,
 			       unsigned int reg, unsigned int mask,
 			       unsigned int value)
 {
-	int change;
-
-	mutex_lock(&codec->mutex);
-	change = snd_soc_update_bits(codec, reg, mask, value);
-	mutex_unlock(&codec->mutex);
-
-	return change;
+	return snd_soc_component_update_bits(&codec->component, reg, mask,
+		value);
 }
 EXPORT_SYMBOL_GPL(snd_soc_update_bits_locked);
 
@@ -120,115 +275,58 @@ EXPORT_SYMBOL_GPL(snd_soc_update_bits_locked);
 int snd_soc_test_bits(struct snd_soc_codec *codec, unsigned int reg,
 				unsigned int mask, unsigned int value)
 {
-	int change;
-	unsigned int old, new;
-
-	old = snd_soc_read(codec, reg);
-	new = (old & ~mask) | value;
-	change = old != new;
-
-	return change;
+	return snd_soc_component_test_bits(&codec->component, reg, mask, value);
 }
 EXPORT_SYMBOL_GPL(snd_soc_test_bits);
 
 int snd_soc_platform_read(struct snd_soc_platform *platform,
 					unsigned int reg)
 {
-	unsigned int ret;
+	unsigned int val;
+	int ret;
 
-	if (!platform->driver->read) {
-		dev_err(platform->dev, "ASoC: platform has no read back\n");
+	ret = snd_soc_component_read(&platform->component, reg, &val);
+	if (ret < 0)
 		return -1;
-	}
 
-	ret = platform->driver->read(platform, reg);
-	dev_dbg(platform->dev, "read %x => %x\n", reg, ret);
-	trace_snd_soc_preg_read(platform, reg, ret);
+	trace_snd_soc_preg_read(platform, reg, val);
 
-	return ret;
+	return val;
 }
 EXPORT_SYMBOL_GPL(snd_soc_platform_read);
 
 int snd_soc_platform_write(struct snd_soc_platform *platform,
 					 unsigned int reg, unsigned int val)
 {
-	if (!platform->driver->write) {
-		dev_err(platform->dev, "ASoC: platform has no write back\n");
-		return -1;
-	}
-
-	dev_dbg(platform->dev, "write %x = %x\n", reg, val);
 	trace_snd_soc_preg_write(platform, reg, val);
-	return platform->driver->write(platform, reg, val);
+	return snd_soc_component_write(&platform->component, reg, val);
 }
 EXPORT_SYMBOL_GPL(snd_soc_platform_write);
 
-#ifdef CONFIG_REGMAP
-static int hw_write(struct snd_soc_codec *codec, unsigned int reg,
-		    unsigned int value)
-{
-	return regmap_write(codec->control_data, reg, value);
-}
-
-static unsigned int hw_read(struct snd_soc_codec *codec, unsigned int reg)
-{
-	int ret;
-	unsigned int val;
-
-	ret = regmap_read(codec->control_data, reg, &val);
-	if (ret == 0)
-		return val;
-	else
-		return -1;
-}
-
 /**
- * snd_soc_codec_set_cache_io: Set up standard I/O functions.
- *
- * @codec: CODEC to configure.
- * @map: Register map to write to
+ * snd_soc_component_init_io() - Initialize regmap IO
  *
- * Register formats are frequently shared between many I2C and SPI
- * devices.  In order to promote code reuse the ASoC core provides
- * some standard implementations of CODEC read and write operations
- * which can be set up using this function.
+ * @component: component to initialize
+ * @regmap: regmap instance to use for IO operations
  *
- * The caller is responsible for allocating and initialising the
- * actual cache.
- *
- * Note that at present this code cannot be used by CODECs with
- * volatile registers.
+ * Return: 0 on success, a negative error code otherwise
  */
-int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
-			       struct regmap *regmap)
+int snd_soc_component_init_io(struct snd_soc_component *component,
+	struct regmap *regmap)
 {
 	int ret;
 
 	if (!regmap)
 		return -EINVAL;
 
-	/* Device has made its own regmap arrangements */
-	codec->control_data = regmap;
-
-	codec->write = hw_write;
-	codec->read = hw_read;
-
-	ret = regmap_get_val_bytes(codec->control_data);
+	ret = regmap_get_val_bytes(regmap);
 	/* Errors are legitimate for non-integer byte
 	 * multiples */
 	if (ret > 0)
-		codec->val_bytes = ret;
+		component->val_bytes = ret;
 
-	codec->using_regmap = true;
+	component->regmap = regmap;
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);
-#else
-int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
-			       struct regmap *regmap)
-{
-	return -ENOTSUPP;
-}
-EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);
-#endif
+EXPORT_SYMBOL_GPL(snd_soc_component_init_io);