ASoC: cs35l56: In secure mode skip SHUTDOWN and RESET around fw download

If the device is in secure mode it's unnecessary to send a SHUTDOWN and
SYSTEM_RESET around the firmware download. It could only be patching
insecure tunings. A tuning patch doesn't need a SHUTDOWN and only needs
a REINIT afterwards. This will reduce the overhead of exiting system
suspend in secure mode.
Signed-off-by: Simon Trimmer <simont@opensource.cirrus.com>
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/Message-Id: <20230518150250.1121006-4-rf@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/cs35l56.h

@@ -223,6 +223,7 @@
 
 #define CS35L56_MBOX_CMD_AUDIO_PLAY			0x0B000001
 #define CS35L56_MBOX_CMD_AUDIO_PAUSE			0x0B000002
+#define CS35L56_MBOX_CMD_AUDIO_REINIT			0x0B000003
 #define CS35L56_MBOX_CMD_HIBERNATE_NOW			0x02000001
 #define CS35L56_MBOX_CMD_WAKEUP				0x02000002
 #define CS35L56_MBOX_CMD_PREVENT_AUTO_HIBERNATE		0x02000003

sound/soc/codecs/cs35l56.c

@@ -825,19 +825,23 @@ static void cs35l56_system_reset(struct cs35l56_private *cs35l56)
 	regcache_cache_only(cs35l56->regmap, false);
 }
 
-static void cs35l56_dsp_work(struct work_struct *work)
+static void cs35l56_secure_patch(struct cs35l56_private *cs35l56)
 {
-	struct cs35l56_private *cs35l56 = container_of(work,
-						       struct cs35l56_private,
-						       dsp_work);
-	unsigned int reg;
-	unsigned int val;
-	int ret = 0;
+	int ret;
 
-	if (!cs35l56->init_done)
-		return;
+	/* Use wm_adsp to load and apply the firmware patch and coefficient files */
+	ret = wm_adsp_power_up(&cs35l56->dsp);
+	if (ret)
+		dev_dbg(cs35l56->dev, "%s: wm_adsp_power_up ret %d\n", __func__, ret);
+	else
+		cs35l56_mbox_send(cs35l56, CS35L56_MBOX_CMD_AUDIO_REINIT);
+}
 
-	pm_runtime_get_sync(cs35l56->dev);
+static void cs35l56_patch(struct cs35l56_private *cs35l56)
+{
+	unsigned int reg;
+	unsigned int val;
+	int ret;
 
 	/*
 	 * Disable SoundWire interrupts to prevent race with IRQ work.
@@ -909,6 +913,29 @@ static void cs35l56_dsp_work(struct work_struct *work)
 		sdw_write_no_pm(cs35l56->sdw_peripheral, CS35L56_SDW_GEN_INT_MASK_1,
 				CS35L56_SDW_INT_MASK_CODEC_IRQ);
 	}
+}
+
+static void cs35l56_dsp_work(struct work_struct *work)
+{
+	struct cs35l56_private *cs35l56 = container_of(work,
+						       struct cs35l56_private,
+						       dsp_work);
+
+	if (!cs35l56->init_done)
+		return;
+
+	pm_runtime_get_sync(cs35l56->dev);
+
+	/*
+	 * When the device is running in secure mode the firmware files can
+	 * only contain insecure tunings and therefore we do not need to
+	 * shutdown the firmware to apply them and can use the lower cost
+	 * reinit sequence instead.
+	 */
+	if (cs35l56->secured)
+		cs35l56_secure_patch(cs35l56);
+	else
+		cs35l56_patch(cs35l56);
 
 	pm_runtime_mark_last_busy(cs35l56->dev);
 	pm_runtime_put_autosuspend(cs35l56->dev);