Merge tag 'asoc-hdmi-codec-improvements-v2' of git://git.kernel.org/p…

…ub/scm/linux/kernel/git/mripard/linux into asoc-5.14

Improvements to the hdmi-codec driver and ALSA infrastructure around it
to support the HDMI Channel Mapping and IEC958 controls

Documentation/sound/kernel-api/writing-an-alsa-driver.rst

@@ -3508,14 +3508,15 @@ field must be set, though).
 
 “IEC958 Playback Con Mask” is used to return the bit-mask for the IEC958
 status bits of consumer mode. Similarly, “IEC958 Playback Pro Mask”
-returns the bitmask for professional mode. They are read-only controls,
-and are defined as MIXER controls (iface =
-``SNDRV_CTL_ELEM_IFACE_MIXER``).
+returns the bitmask for professional mode. They are read-only controls.
 
 Meanwhile, “IEC958 Playback Default” control is defined for getting and
-setting the current default IEC958 bits. Note that this one is usually
-defined as a PCM control (iface = ``SNDRV_CTL_ELEM_IFACE_PCM``),
-although in some places it's defined as a MIXER control.
+setting the current default IEC958 bits.
+
+Due to historical reasons, both variants of the Playback Mask and the
+Playback Default controls can be implemented on either a
+``SNDRV_CTL_ELEM_IFACE_PCM`` or a ``SNDRV_CTL_ELEM_IFACE_MIXER`` iface.
+Drivers should expose the mask and default on the same iface though.
 
 In addition, you can define the control switches to enable/disable or to
 set the raw bit mode. The implementation will depend on the chip, but

include/sound/hdmi-codec.h

@@ -65,12 +65,22 @@ struct hdmi_codec_ops {
 
 	/*
 	 * Configures HDMI-encoder for audio stream.
-	 * Mandatory
+	 * Having either prepare or hw_params is mandatory.
 	 */
 	int (*hw_params)(struct device *dev, void *data,
 			 struct hdmi_codec_daifmt *fmt,
 			 struct hdmi_codec_params *hparms);
 
+	/*
+	 * Configures HDMI-encoder for audio stream. Can be called
+	 * multiple times for each setup.
+	 *
+	 * Having either prepare or hw_params is mandatory.
+	 */
+	int (*prepare)(struct device *dev, void *data,
+		       struct hdmi_codec_daifmt *fmt,
+		       struct hdmi_codec_params *hparms);
+
 	/*
 	 * Shuts down the audio stream.
 	 * Mandatory

include/sound/pcm_iec958.h

@@ -4,6 +4,14 @@
 
 #include <linux/types.h>
 
+int snd_pcm_create_iec958_consumer_default(u8 *cs, size_t len);
+
+int snd_pcm_fill_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
+				 size_t len);
+
+int snd_pcm_fill_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
+					   u8 *cs, size_t len);
+
 int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
 	size_t len);
 

sound/core/pcm_iec958.c

@@ -9,41 +9,85 @@
 #include <sound/pcm_params.h>
 #include <sound/pcm_iec958.h>
 
-static int create_iec958_consumer(uint rate, uint sample_width,
-				  u8 *cs, size_t len)
+/**
+ * snd_pcm_create_iec958_consumer_default - create default consumer format IEC958 channel status
+ * @cs: channel status buffer, at least four bytes
+ * @len: length of channel status buffer
+ *
+ * Create the consumer format channel status data in @cs of maximum size
+ * @len. When relevant, the configuration-dependant bits will be set as
+ * unspecified.
+ *
+ * Drivers should then call einter snd_pcm_fill_iec958_consumer() or
+ * snd_pcm_fill_iec958_consumer_hw_params() to replace these unspecified
+ * bits by their actual values.
+ *
+ * Drivers may wish to tweak the contents of the buffer after creation.
+ *
+ * Returns: length of buffer, or negative error code if something failed.
+ */
+int snd_pcm_create_iec958_consumer_default(u8 *cs, size_t len)
 {
-	unsigned int fs, ws;
-
 	if (len < 4)
 		return -EINVAL;
 
-	switch (rate) {
-	case 32000:
-		fs = IEC958_AES3_CON_FS_32000;
-		break;
-	case 44100:
-		fs = IEC958_AES3_CON_FS_44100;
-		break;
-	case 48000:
-		fs = IEC958_AES3_CON_FS_48000;
-		break;
-	case 88200:
-		fs = IEC958_AES3_CON_FS_88200;
-		break;
-	case 96000:
-		fs = IEC958_AES3_CON_FS_96000;
-		break;
-	case 176400:
-		fs = IEC958_AES3_CON_FS_176400;
-		break;
-	case 192000:
-		fs = IEC958_AES3_CON_FS_192000;
-		break;
-	default:
+	memset(cs, 0, len);
+
+	cs[0] = IEC958_AES0_CON_NOT_COPYRIGHT | IEC958_AES0_CON_EMPHASIS_NONE;
+	cs[1] = IEC958_AES1_CON_GENERAL;
+	cs[2] = IEC958_AES2_CON_SOURCE_UNSPEC | IEC958_AES2_CON_CHANNEL_UNSPEC;
+	cs[3] = IEC958_AES3_CON_CLOCK_1000PPM | IEC958_AES3_CON_FS_NOTID;
+
+	if (len > 4)
+		cs[4] = IEC958_AES4_CON_WORDLEN_NOTID;
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(snd_pcm_create_iec958_consumer_default);
+
+static int fill_iec958_consumer(uint rate, uint sample_width,
+				u8 *cs, size_t len)
+{
+	if (len < 4)
 		return -EINVAL;
+
+	if ((cs[3] & IEC958_AES3_CON_FS) == IEC958_AES3_CON_FS_NOTID) {
+		unsigned int fs;
+
+		switch (rate) {
+			case 32000:
+				fs = IEC958_AES3_CON_FS_32000;
+				break;
+			case 44100:
+				fs = IEC958_AES3_CON_FS_44100;
+				break;
+			case 48000:
+				fs = IEC958_AES3_CON_FS_48000;
+				break;
+			case 88200:
+				fs = IEC958_AES3_CON_FS_88200;
+				break;
+			case 96000:
+				fs = IEC958_AES3_CON_FS_96000;
+				break;
+			case 176400:
+				fs = IEC958_AES3_CON_FS_176400;
+				break;
+			case 192000:
+				fs = IEC958_AES3_CON_FS_192000;
+				break;
+			default:
+				return -EINVAL;
+		}
+
+		cs[3] &= ~IEC958_AES3_CON_FS;
+		cs[3] |= fs;
 	}
 
-	if (len > 4) {
+	if (len > 4 &&
+	    (cs[4] & IEC958_AES4_CON_WORDLEN) == IEC958_AES4_CON_WORDLEN_NOTID) {
+		unsigned int ws;
+
 		switch (sample_width) {
 		case 16:
 			ws = IEC958_AES4_CON_WORDLEN_20_16;
@@ -64,20 +108,57 @@ static int create_iec958_consumer(uint rate, uint sample_width,
 		default:
 			return -EINVAL;
 		}
-	}
 
-	memset(cs, 0, len);
+		cs[4] &= ~IEC958_AES4_CON_WORDLEN;
+		cs[4] |= ws;
+	}
 
-	cs[0] = IEC958_AES0_CON_NOT_COPYRIGHT | IEC958_AES0_CON_EMPHASIS_NONE;
-	cs[1] = IEC958_AES1_CON_GENERAL;
-	cs[2] = IEC958_AES2_CON_SOURCE_UNSPEC | IEC958_AES2_CON_CHANNEL_UNSPEC;
-	cs[3] = IEC958_AES3_CON_CLOCK_1000PPM | fs;
+	return len;
+}
 
-	if (len > 4)
-		cs[4] = ws;
+/**
+ * snd_pcm_fill_iec958_consumer - Fill consumer format IEC958 channel status
+ * @runtime: pcm runtime structure with ->rate filled in
+ * @cs: channel status buffer, at least four bytes
+ * @len: length of channel status buffer
+ *
+ * Fill the unspecified bits in an IEC958 status bits array using the
+ * parameters of the PCM runtime @runtime.
+ *
+ * Drivers may wish to tweak the contents of the buffer after its been
+ * filled.
+ *
+ * Returns: length of buffer, or negative error code if something failed.
+ */
+int snd_pcm_fill_iec958_consumer(struct snd_pcm_runtime *runtime,
+				 u8 *cs, size_t len)
+{
+	return fill_iec958_consumer(runtime->rate,
+				    snd_pcm_format_width(runtime->format),
+				    cs, len);
+}
+EXPORT_SYMBOL_GPL(snd_pcm_fill_iec958_consumer);
 
-	return len;
+/**
+ * snd_pcm_fill_iec958_consumer_hw_params - Fill consumer format IEC958 channel status
+ * @params: the hw_params instance for extracting rate and sample format
+ * @cs: channel status buffer, at least four bytes
+ * @len: length of channel status buffer
+ *
+ * Fill the unspecified bits in an IEC958 status bits array using the
+ * parameters of the PCM hardware parameters @params.
+ *
+ * Drivers may wish to tweak the contents of the buffer after its been
+ * filled..
+ *
+ * Returns: length of buffer, or negative error code if something failed.
+ */
+int snd_pcm_fill_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
+					   u8 *cs, size_t len)
+{
+	return fill_iec958_consumer(params_rate(params), params_width(params), cs, len);
 }
+EXPORT_SYMBOL_GPL(snd_pcm_fill_iec958_consumer_hw_params);
 
 /**
  * snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status
@@ -95,9 +176,13 @@ static int create_iec958_consumer(uint rate, uint sample_width,
 int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
 	size_t len)
 {
-	return create_iec958_consumer(runtime->rate,
-				      snd_pcm_format_width(runtime->format),
-				      cs, len);
+	int ret;
+
+	ret = snd_pcm_create_iec958_consumer_default(cs, len);
+	if (ret < 0)
+		return ret;
+
+	return snd_pcm_fill_iec958_consumer(runtime, cs, len);
 }
 EXPORT_SYMBOL(snd_pcm_create_iec958_consumer);
 
@@ -117,7 +202,12 @@ EXPORT_SYMBOL(snd_pcm_create_iec958_consumer);
 int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
 					     u8 *cs, size_t len)
 {
-	return create_iec958_consumer(params_rate(params), params_width(params),
-				      cs, len);
+	int ret;
+
+	ret = snd_pcm_create_iec958_consumer_default(cs, len);
+	if (ret < 0)
+		return ret;
+
+	return fill_iec958_consumer(params_rate(params), params_width(params), cs, len);
 }
 EXPORT_SYMBOL(snd_pcm_create_iec958_consumer_hw_params);