ASoC: dsp - Add ASoC DSP core

This adds ASoC core support for internal and external DSPs and represents them
to the audio user as a CODEC like device with mixers, muxes and runtime audio
route changing.

The DSP core allows DSP DAIs to be dynamically re-routed at runtime between the
PCM device end (or Frontend - FE) and the physical DAI (Backend - BE) using
regular kcontrols (just like a hardware CODEC).

The DSP core also deal with DSP FE+BE suspend and resume PM ops.

Signed-off-by: Liam Girdwood <lrg@ti.com>
diff --git a/include/sound/soc-dsp.h b/include/sound/soc-dsp.h
new file mode 100644
index 0000000..b10360e
--- /dev/null
+++ b/include/sound/soc-dsp.h
@@ -0,0 +1,129 @@
+/*
+ * linux/sound/soc-dsp.h -- ALSA SoC DSP
+ *
+ * Author:		Liam Girdwood <lrg@slimlogic.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __LINUX_SND_SOC_DSP_H
+#define __LINUX_SND_SOC_DSP_H
+
+#include <sound/pcm.h>
+
+struct snd_soc_dapm_widget;
+
+/*
+ * DSP trigger ordering. Triggering flexibility is required as some DSPs
+ * require triggering before/after their clients/hosts.
+ *
+ * i.e. some clients may want to manually order this call in their PCM
+ * trigger() whilst others will just use the regular core ordering.
+ */
+enum snd_soc_dsp_trigger {
+	SND_SOC_DSP_TRIGGER_PRE		= 0,
+	SND_SOC_DSP_TRIGGER_POST,
+	SND_SOC_DSP_TRIGGER_BESPOKE,
+};
+
+/*
+ * The DSP Backend state.
+ */
+enum snd_soc_dsp_link_state {
+	SND_SOC_DSP_LINK_STATE_NEW	= 0,	/* newly created path */
+	SND_SOC_DSP_LINK_STATE_FREE,			/* path to be dismantled */
+	SND_SOC_DSP_LINK_STATE_HW_PARAMS,		/* path hw_params configured */
+	SND_SOC_DSP_LINK_STATE_PREPARE,		/* path is prepared */
+	SND_SOC_DSP_LINK_STATE_START,		/* path is started */
+	SND_SOC_DSP_LINK_STATE_PAUSED,		/* path is paused */
+};
+
+struct snd_soc_dsp_params {
+	struct snd_soc_pcm_runtime *be;
+	struct snd_soc_pcm_runtime *fe;
+	enum snd_soc_dsp_link_state state;
+	struct list_head list_be;
+	struct list_head list_fe;
+	struct snd_pcm_hw_params params;
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *debugfs_state;
+#endif
+};
+
+struct snd_soc_dsp_link {
+	/* supported BE */
+	const char **supported_be;
+	int num_be;
+	/* supported channels */
+	int fe_playback_channels;
+	int fe_capture_channels;
+
+	enum snd_soc_dsp_trigger trigger[2];
+};
+
+/* FE DSP PCM ops - called by soc-core */
+int soc_dsp_fe_dai_open(struct snd_pcm_substream *substream);
+int soc_dsp_fe_dai_close(struct snd_pcm_substream *substream);
+int soc_dsp_fe_dai_prepare(struct snd_pcm_substream *substream);
+int soc_dsp_fe_dai_hw_free(struct snd_pcm_substream *substream);
+int soc_dsp_fe_dai_trigger(struct snd_pcm_substream *substream, int cmd);
+int soc_dsp_fe_dai_hw_params(struct snd_pcm_substream *substream,
+				    struct snd_pcm_hw_params *params);
+
+/* Backend DSP trigger.
+ * Can be called by core or components depending on trigger config.
+ */
+int soc_dsp_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, int cmd);
+
+/* Is this trigger() call required for this BE and stream */
+static inline int snd_soc_dsp_is_trigger_for_be(struct snd_soc_pcm_runtime *fe,
+		struct snd_soc_pcm_runtime *be, int stream)
+{
+	if (!fe->dsp[stream].runtime_update)
+		return 1;
+	else if (be->dsp[stream].runtime_update)
+		return 1;
+	else
+		return 0;
+}
+
+/* Is this trigger() call required for this FE and stream */
+static inline int snd_soc_dsp_is_trigger_for_fe(struct snd_soc_pcm_runtime *fe,
+		int stream)
+{
+	return !fe->dsp[stream].runtime_update;
+}
+
+static inline int snd_soc_dsp_platform_trigger(struct snd_pcm_substream *substream,
+	int cmd, struct snd_soc_platform *platform)
+{
+	if (platform->driver->ops->trigger)
+		return platform->driver->ops->trigger(substream, cmd);
+	return 0;
+}
+
+/* Runtime update - open/close Backend DSP paths depending on mixer updates */
+int soc_dsp_runtime_update(struct snd_soc_dapm_widget *widget);
+
+/* Backend DSP suspend and resume */
+int soc_dsp_be_digital_mute(struct snd_soc_pcm_runtime *fe, int mute);
+int soc_dsp_be_cpu_dai_suspend(struct snd_soc_pcm_runtime *fe);
+int soc_dsp_be_ac97_cpu_dai_suspend(struct snd_soc_pcm_runtime *fe);
+int soc_dsp_be_platform_suspend(struct snd_soc_pcm_runtime *fe);
+int soc_dsp_be_cpu_dai_resume(struct snd_soc_pcm_runtime *fe);
+int soc_dsp_be_ac97_cpu_dai_resume(struct snd_soc_pcm_runtime *fe);
+int soc_dsp_be_platform_resume(struct snd_soc_pcm_runtime *fe);
+
+/* DAPM stream events for Backend DSP paths */
+int soc_dsp_dapm_stream_event(struct snd_soc_pcm_runtime *fe,
+	int dir, const char *stream, int event);
+
+static inline struct snd_pcm_substream *snd_soc_dsp_get_substream(
+		struct snd_soc_pcm_runtime *be, int stream)
+{
+	return be->pcm->streams[stream].substream;
+}
+
+#endif