ASoC: Extend wm_adsp so cs35l56 can suppress controls

Merge series from Simon Trimmer <simont@opensource.cirrus.com>:

This pair of patches extend wm_adsp to add a callback that can be used
to control whether ALSA controls are added and then tweak cs35l56 to use
it to suppress controls made from firmware coefficients.

sound/soc/codecs/cs35l56.c

@@ -1095,6 +1095,11 @@ int cs35l56_system_resume(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(cs35l56_system_resume);
 
+static int cs35l56_control_add_nop(struct wm_adsp *dsp, struct cs_dsp_coeff_ctl *cs_ctl)
+{
+	return 0;
+}
+
 static int cs35l56_dsp_init(struct cs35l56_private *cs35l56)
 {
 	struct wm_adsp *dsp;
@@ -1117,6 +1122,12 @@ static int cs35l56_dsp_init(struct cs35l56_private *cs35l56)
 	dsp->fw = 12;
 	dsp->wmfw_optional = true;
 
+	/*
+	 * None of the firmware controls need to be exported so add a no-op
+	 * callback that suppresses creating an ALSA control.
+	 */
+	dsp->control_add = &cs35l56_control_add_nop;
+
 	dev_dbg(cs35l56->base.dev, "DSP system name: '%s'\n", dsp->system_name);
 
 	ret = wm_halo_init(dsp);

sound/soc/codecs/wm_adsp.c

@@ -583,7 +583,7 @@ static void wm_adsp_ctl_work(struct work_struct *work)
 	kfree(kcontrol);
 }
 
-static int wm_adsp_control_add(struct cs_dsp_coeff_ctl *cs_ctl)
+int wm_adsp_control_add(struct cs_dsp_coeff_ctl *cs_ctl)
 {
 	struct wm_adsp *dsp = container_of(cs_ctl->dsp, struct wm_adsp, cs_dsp);
 	struct cs_dsp *cs_dsp = &dsp->cs_dsp;
@@ -658,6 +658,17 @@ static int wm_adsp_control_add(struct cs_dsp_coeff_ctl *cs_ctl)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(wm_adsp_control_add);
+
+static int wm_adsp_control_add_cb(struct cs_dsp_coeff_ctl *cs_ctl)
+{
+	struct wm_adsp *dsp = container_of(cs_ctl->dsp, struct wm_adsp, cs_dsp);
+
+	if (dsp->control_add)
+		return (dsp->control_add)(dsp, cs_ctl);
+	else
+		return wm_adsp_control_add(cs_ctl);
+}
 
 static void wm_adsp_control_remove(struct cs_dsp_coeff_ctl *cs_ctl)
 {
@@ -2072,12 +2083,12 @@ irqreturn_t wm_halo_wdt_expire(int irq, void *data)
 EXPORT_SYMBOL_GPL(wm_halo_wdt_expire);
 
 static const struct cs_dsp_client_ops wm_adsp1_client_ops = {
-	.control_add = wm_adsp_control_add,
+	.control_add = wm_adsp_control_add_cb,
 	.control_remove = wm_adsp_control_remove,
 };
 
 static const struct cs_dsp_client_ops wm_adsp2_client_ops = {
-	.control_add = wm_adsp_control_add,
+	.control_add = wm_adsp_control_add_cb,
 	.control_remove = wm_adsp_control_remove,
 	.pre_run = wm_adsp_pre_run,
 	.post_run = wm_adsp_event_post_run,

sound/soc/codecs/wm_adsp.h

@@ -37,6 +37,7 @@ struct wm_adsp {
 	bool wmfw_optional;
 
 	struct work_struct boot_work;
+	int (*control_add)(struct wm_adsp *dsp, struct cs_dsp_coeff_ctl *cs_ctl);
 	int (*pre_run)(struct wm_adsp *dsp);
 
 	bool preloaded;
@@ -132,6 +133,8 @@ int wm_adsp_compr_pointer(struct snd_soc_component *component,
 int wm_adsp_compr_copy(struct snd_soc_component *component,
 		       struct snd_compr_stream *stream,
 		       char __user *buf, size_t count);
+
+int wm_adsp_control_add(struct cs_dsp_coeff_ctl *cs_ctl);
 int wm_adsp_write_ctl(struct wm_adsp *dsp, const char *name,  int type,
 		      unsigned int alg, void *buf, size_t len);
 int wm_adsp_read_ctl(struct wm_adsp *dsp, const char *name,  int type,