ASoC: rsnd: Add SSI reset support for RZ/G3E platform

Acquire the per-SSI reset controller and pass it through
rsnd_mod_init() so it is wired into the rsnd_mod->rstc plumbing.

The RZ/G3E SoC exposes one reset line per SSI instance. Use the
indexed-name rsnd_devm_reset_control_get_optional_indexed() helper
so the same code accepts both the hyphenated RZ/G3E names
("ssi-0", "ssi-1", ...) and the legacy dotted names used by R-Car
("ssi.0", ...).

The helper returns NULL when no reset is described in DT, leaving
existing R-Car generations unaffected.

Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://patch.msgid.link/20260525110230.4014435-12-john.madieu.xa@bp.renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: John Madieu

sound/soc/renesas/rcar/ssi.c

@@ -1157,6 +1157,7 @@ int __rsnd_ssi_is_pin_sharing(struct rsnd_mod *mod)
 
 int rsnd_ssi_probe(struct rsnd_priv *priv)
 {
+	struct reset_control *rstc;
 	struct device_node *node;
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct rsnd_mod_ops *ops;
@@ -1202,6 +1203,17 @@ int rsnd_ssi_probe(struct rsnd_priv *priv)
 			goto rsnd_ssi_probe_done;
 		}
 
+		/*
+		 * RZ/G3E uses per-SSI reset controllers.
+		 * R-Car platforms typically don't have SSI reset controls.
+		 */
+		rstc = rsnd_devm_reset_control_get_optional_indexed(dev,
+								    SSI_NAME, i);
+		if (IS_ERR(rstc)) {
+			ret = PTR_ERR(rstc);
+			goto rsnd_ssi_probe_done;
+		}
+
 		if (of_property_read_bool(np, "shared-pin"))
 			rsnd_flags_set(ssi, RSND_SSI_CLK_PIN_SHARE);
 
@@ -1220,7 +1232,7 @@ int rsnd_ssi_probe(struct rsnd_priv *priv)
 			ops = &rsnd_ssi_dma_ops;
 
 		ret = rsnd_mod_init(priv, rsnd_mod_get(ssi), ops, clk,
-				    NULL, RSND_MOD_SSI, i);
+				    rstc, RSND_MOD_SSI, i);
 		if (ret)
 			goto rsnd_ssi_probe_done;