ASoc: tas2781: Enable RCA-based playback without DSP firmware download

In only loading RCA (Reconfigurable Architecture) binary case, no DSP
program will be working inside tas2563/tas2781, that is dsp-bypass mode,
do not support speaker protection, or audio acoustic algorithms in this
mode.

Fixes: ef3bcde75d ("ASoC: tas2781: Add tas2781 driver")
Signed-off-by: Shenghao Ding <shenghao-ding@ti.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://msgid.link/r/20240614133646.910-1-shenghao-ding@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/tas2781-dsp.h

@@ -117,10 +117,17 @@ struct tasdevice_fw {
 	struct device *dev;
 };
 
-enum tasdevice_dsp_fw_state {
+enum tasdevice_fw_state {
-	TASDEVICE_DSP_FW_NONE = 0,
+	/* Driver in startup mode, not load any firmware. */
 	TASDEVICE_DSP_FW_PENDING,
+	/* DSP firmware in the system, but parsing error. */
 	TASDEVICE_DSP_FW_FAIL,
+	/*
+	 * Only RCA (Reconfigurable Architecture) firmware load
+	 * successfully.
+	 */
+	TASDEVICE_RCA_FW_OK,
+	/* Both RCA and DSP firmware load successfully. */
 	TASDEVICE_DSP_FW_ALL_OK,
 };
 

sound/soc/codecs/tas2781-fmwlib.c

@@ -2324,14 +2324,21 @@ void tasdevice_tuning_switch(void *context, int state)
 	struct tasdevice_fw *tas_fmw = tas_priv->fmw;
 	int profile_cfg_id = tas_priv->rcabin.profile_cfg_id;
 
-	if (tas_priv->fw_state == TASDEVICE_DSP_FW_FAIL) {
+	/*
-		dev_err(tas_priv->dev, "DSP bin file not loaded\n");
+	 * Only RCA-based Playback can still work with no dsp program running
+	 * inside the chip.
+	 */
+	switch (tas_priv->fw_state) {
+	case TASDEVICE_RCA_FW_OK:
+	case TASDEVICE_DSP_FW_ALL_OK:
+		break;
+	default:
 		return;
 	}
 
 	if (state == 0) {
-		if (tas_priv->cur_prog < tas_fmw->nr_programs) {
+		if (tas_fmw && tas_priv->cur_prog < tas_fmw->nr_programs) {
-			/*dsp mode or tuning mode*/
+			/* dsp mode or tuning mode */
 			profile_cfg_id = tas_priv->rcabin.profile_cfg_id;
 			tasdevice_select_tuningprm_cfg(tas_priv,
 				tas_priv->cur_prog, tas_priv->cur_conf,
@@ -2340,9 +2347,10 @@ void tasdevice_tuning_switch(void *context, int state)
 
 		tasdevice_select_cfg_blk(tas_priv, profile_cfg_id,
 			TASDEVICE_BIN_BLK_PRE_POWER_UP);
-	} else
+	} else {
 		tasdevice_select_cfg_blk(tas_priv, profile_cfg_id,
 			TASDEVICE_BIN_BLK_PRE_SHUTDOWN);
+	}
 }
 EXPORT_SYMBOL_NS_GPL(tasdevice_tuning_switch,
 	SND_SOC_TAS2781_FMWLIB);

sound/soc/codecs/tas2781-i2c.c

@@ -380,23 +380,37 @@ static void tasdevice_fw_ready(const struct firmware *fmw,
 	mutex_lock(&tas_priv->codec_lock);
 
 	ret = tasdevice_rca_parser(tas_priv, fmw);
-	if (ret)
+	if (ret) {
+		tasdevice_config_info_remove(tas_priv);
 		goto out;
+	}
 	tasdevice_create_control(tas_priv);
 
 	tasdevice_dsp_remove(tas_priv);
 	tasdevice_calbin_remove(tas_priv);
-	tas_priv->fw_state = TASDEVICE_DSP_FW_PENDING;
+	/*
+	 * The baseline is the RCA-only case, and then the code attempts to
+	 * load DSP firmware but in case of failures just keep going, i.e.
+	 * failing to load DSP firmware is NOT an error.
+	 */
+	tas_priv->fw_state = TASDEVICE_RCA_FW_OK;
 	scnprintf(tas_priv->coef_binaryname, 64, "%s_coef.bin",
 		tas_priv->dev_name);
 	ret = tasdevice_dsp_parser(tas_priv);
 	if (ret) {
 		dev_err(tas_priv->dev, "dspfw load %s error\n",
 			tas_priv->coef_binaryname);
-		tas_priv->fw_state = TASDEVICE_DSP_FW_FAIL;
 		goto out;
 	}
-	tasdevice_dsp_create_ctrls(tas_priv);
+
+	/*
+	 * If no dsp-related kcontrol created, the dsp resource will be freed.
+	 */
+	ret = tasdevice_dsp_create_ctrls(tas_priv);
+	if (ret) {
+		dev_err(tas_priv->dev, "dsp controls error\n");
+		goto out;
+	}
 
 	tas_priv->fw_state = TASDEVICE_DSP_FW_ALL_OK;
 
@@ -417,9 +431,8 @@ static void tasdevice_fw_ready(const struct firmware *fmw,
 	tasdevice_prmg_load(tas_priv, 0);
 	tas_priv->cur_prog = 0;
 out:
-	if (tas_priv->fw_state == TASDEVICE_DSP_FW_FAIL) {
+	if (tas_priv->fw_state == TASDEVICE_RCA_FW_OK) {
-		/*If DSP FW fail, kcontrol won't be created */
+		/* If DSP FW fail, DSP kcontrol won't be created. */
-		tasdevice_config_info_remove(tas_priv);
 		tasdevice_dsp_remove(tas_priv);
 	}
 	mutex_unlock(&tas_priv->codec_lock);
@@ -466,14 +479,14 @@ static int tasdevice_startup(struct snd_pcm_substream *substream,
 {
 	struct snd_soc_component *codec = dai->component;
 	struct tasdevice_priv *tas_priv = snd_soc_component_get_drvdata(codec);
-	int ret = 0;
 
-	if (tas_priv->fw_state != TASDEVICE_DSP_FW_ALL_OK) {
+	switch (tas_priv->fw_state) {
-		dev_err(tas_priv->dev, "DSP bin file not loaded\n");
+	case TASDEVICE_RCA_FW_OK:
-		ret = -EINVAL;
+	case TASDEVICE_DSP_FW_ALL_OK:
+		return 0;
+	default:
+		return -EINVAL;
 	}
-
-	return ret;
 }
 
 static int tasdevice_hw_params(struct snd_pcm_substream *substream,