[PATCH v6 10/16] ASoC: rsnd: Add SSI reset support for RZ/G3E platform

[John Madieu]

Add SSI reset support for the Renesas RZ/G3E SoC, which differs from
earlier generations in several ways:

 - The SSI block always operates in BUSIF mode; RZ/G3E does not
   implement the SSITDR/SSIRDR registers used by R-Car Gen2/Gen3/Gen4
   for direct SSI DMA. Consequently, for the RZ/G3E, all audio data
   must pass through BUSIF. PIO mode remains available for R-Car
   Gen2/Gen3/Gen4 platforms.
 - Each SSI instance has its own reset line, exposed using per-SSI
   names such as "ssi-0", "ssi-1", etc., rather than a single shared
   reset.

To support these differences, rsnd_ssi_use_busif() always returns 1
on RZ/G3E, ensuring that the driver consistently selects the BUSIF
DMA path. While at it, acquire the per-SSI reset controller through
the indexed-name helper added earlier in the series, so the same code
accepts both the hyphenated RZ/G3E names and the legacy dotted names
used by R-Car.

Signed-off-by: John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
---

Changes:

v6:
 - Acquire the per-SSI reset through the new
   rsnd_devm_reset_control_get_optional_indexed() helper from
   patch 04/16, so the same code accepts both the hyphenated
   RZ/G3E names ("ssi-0") and the legacy dotted names ("ssi.0").
 - Rewrite the commit message accordingly.

v5: No changes

v4:
 - Clarify in commit message that PIO mode remains available on
   R-Car Gen2/Gen3/Gen4 platforms.

v3: No changes
v2: No changes

 sound/soc/renesas/rcar/ssi.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/sound/soc/renesas/rcar/ssi.c b/sound/soc/renesas/rcar/ssi.c
index cf98cc9ee44c..e6734671328c 100644
--- a/sound/soc/renesas/rcar/ssi.c
+++ b/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;
 
-- 
2.25.1