[PATCH v7 09/18] ASoC: rsnd: ssiu: Add shared SSI reset controller support

[John Madieu]

The RZ/G3E SoC exposes a single shared "ssi-all" reset that gates all
SSI/SSIU modules. Acquire it at SSIU probe and pass it through
rsnd_mod_init() so it is wired into the rsnd_mod->rstc plumbing.

devm_reset_control_get_optional_shared() returns NULL when no reset is
described in DT, leaving existing R-Car generations unaffected.

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

Changes:

v7: New patch. Split out of [PATCH v6 09/16] "ASoC: rsnd: ssui: Add
    RZ/G3E SSIU BUSIF support" per Kuninori Morimoto's request that
    the reset, the BUSIF layout and busif_status_count be separate
    changes. This patch carries only the shared "ssi-all" reset
    acquisition in rsnd_ssiu_probe() and its rsnd_mod_init()
    plumbing; it is a no-op for non-RZ/G3E DTs.

 sound/soc/renesas/rcar/ssiu.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/sound/soc/renesas/rcar/ssiu.c b/sound/soc/renesas/rcar/ssiu.c
index 0cfa84fe5ea8..2b922ead62d0 100644
--- a/sound/soc/renesas/rcar/ssiu.c
+++ b/sound/soc/renesas/rcar/ssiu.c
@@ -510,6 +510,7 @@ int rsnd_ssiu_probe(struct rsnd_priv *priv)
 {
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct device_node *node __free(device_node) = rsnd_ssiu_of_node(priv);
+	struct reset_control *rstc;
 	struct rsnd_ssiu *ssiu;
 	struct rsnd_mod_ops *ops;
 	const int *list = NULL;
@@ -564,6 +565,12 @@ int rsnd_ssiu_probe(struct rsnd_priv *priv)
 		}
 	}
 
+	/* Acquire shared reset once for all SSIU modules */
+	rstc = devm_reset_control_get_optional_shared(dev, "ssi-all");
+	if (IS_ERR(rstc))
+		return dev_err_probe(dev, PTR_ERR(rstc),
+				     "failed to get ssi-all reset\n");
+
 	for_each_rsnd_ssiu(ssiu, priv, i) {
 		int ret;
 
@@ -586,7 +593,7 @@ int rsnd_ssiu_probe(struct rsnd_priv *priv)
 		}
 
 		ret = rsnd_mod_init(priv, rsnd_mod_get(ssiu),
-				    ops, NULL, NULL, RSND_MOD_SSIU, i);
+				    ops, NULL, rstc, RSND_MOD_SSIU, i);
 		if (ret)
 			return ret;
 	}
-- 
2.25.1