ASoC: Implement DC servo completion IRQ handling for wm_hubs devices

The individual devices should set the flag dcs_done_irq in the hubs
shared data structure to indicate that they will flag the interrupt
by calling wm_hubs_dcs_done().
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/wm_hubs.c

@@ -63,9 +63,11 @@ static const struct soc_enum speaker_mode =
 
 static void wait_for_dc_servo(struct snd_soc_codec *codec, unsigned int op)
 {
+	struct wm_hubs_data *hubs = snd_soc_codec_get_drvdata(codec);
 	unsigned int reg;
 	int count = 0;
 	unsigned int val;
+	unsigned long timeout;
 
 	val = op | WM8993_DCS_ENA_CHAN_0 | WM8993_DCS_ENA_CHAN_1;
 
@@ -74,18 +76,37 @@ static void wait_for_dc_servo(struct snd_soc_codec *codec, unsigned int op)
 
 	dev_dbg(codec->dev, "Waiting for DC servo...\n");
 
-	do {
-		count++;
-		msleep(1);
+	if (hubs->dcs_done_irq) {
+		timeout = wait_for_completion_timeout(&hubs->dcs_done,
+						      msecs_to_jiffies(500));
+		if (timeout == 0)
+			dev_warn(codec->dev, "No DC servo interrupt\n");
+
 		reg = snd_soc_read(codec, WM8993_DC_SERVO_0);
-		dev_dbg(codec->dev, "DC servo: %x\n", reg);
-	} while (reg & op && count < 400);
+	} else {
+		do {
+			count++;
+			msleep(1);
+			reg = snd_soc_read(codec, WM8993_DC_SERVO_0);
+			dev_dbg(codec->dev, "DC servo: %x\n", reg);
+		} while (reg & op && count < 400);
+	}
 
 	if (reg & op)
 		dev_err(codec->dev, "Timed out waiting for DC Servo %x\n",
 			op);
 }
 
+irqreturn_t wm_hubs_dcs_done(int irq, void *data)
+{
+	struct wm_hubs_data *hubs = data;
+
+	complete(&hubs->dcs_done);
+
+	return IRQ_HANDLED;
+}
+EXPORT_SYMBOL_GPL(wm_hubs_dcs_done);
+
 /*
  * Startup calibration of the DC servo
  */
@@ -863,8 +884,11 @@ EXPORT_SYMBOL_GPL(wm_hubs_add_analogue_controls);
 int wm_hubs_add_analogue_routes(struct snd_soc_codec *codec,
 				int lineout1_diff, int lineout2_diff)
 {
+	struct wm_hubs_data *hubs = snd_soc_codec_get_drvdata(codec);
 	struct snd_soc_dapm_context *dapm = &codec->dapm;
 
+	init_completion(&hubs->dcs_done);
+
 	snd_soc_dapm_add_routes(dapm, analogue_routes,
 				ARRAY_SIZE(analogue_routes));
 

sound/soc/codecs/wm_hubs.h

@@ -14,6 +14,9 @@
 #ifndef _WM_HUBS_H
 #define _WM_HUBS_H
 
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+
 struct snd_soc_codec;
 
 extern const unsigned int wm_hubs_spkmix_tlv[];
@@ -28,6 +31,9 @@ struct wm_hubs_data {
 
 	bool class_w;
 	u16 class_w_dcs;
+
+	bool dcs_done_irq;
+	struct completion dcs_done;
 };
 
 extern int wm_hubs_add_analogue_controls(struct snd_soc_codec *);
@@ -38,4 +44,6 @@ extern int wm_hubs_handle_analogue_pdata(struct snd_soc_codec *,
 					 int jd_scthr, int jd_thr,
 					 int micbias1_lvl, int micbias2_lvl);
 
+extern irqreturn_t wm_hubs_dcs_done(int irq, void *data);
+
 #endif