ALSA: hda: cs35l41: Assert reset before system suspend

Some system suspend modes may remove power supplies.
To ensure we are not running during this time, we should assert reset.

Note: since the amps use a shared reset, asserting reset prior to
system suspend only works if the amps are suspended in the reverse
order to probe.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20231026150558.2105827-3-sbinding@opensource.cirrus.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Author: Stefan Binding

sound/pci/hda/cs35l41_hda.c

@@ -813,14 +813,17 @@ static int cs35l41_system_suspend(struct device *dev)
 
 	/* Shutdown DSP before system suspend */
 	ret = cs35l41_ready_for_reset(cs35l41);
-
 	if (ret)
 		dev_err(dev, "System Suspend Failed, not ready for Reset: %d\n", ret);
 
-	/*
-	 * Reset GPIO may be shared, so cannot reset here.
-	 * However beyond this point, amps may be powered down.
-	 */
+	if (cs35l41->reset_gpio) {
+		dev_info(cs35l41->dev, "Asserting Reset\n");
+		gpiod_set_value_cansleep(cs35l41->reset_gpio, 0);
+		usleep_range(2000, 2100);
+	}
+
+	dev_dbg(cs35l41->dev, "System Suspended\n");
+
 	return ret;
 }