[PATCH v2 15/24] ASoC: rsnd: src: Add SRC reset and clock support for RZ/G3E

John Madieu
2026-04-02T09:09:20Z

The RZ/G3E SoC requires explicit SCU (Sampling Rate Converter Unit)
reset and clock management unlike previous R-Car generations:

- scu_clk: SCU module clock
- scu_clkx2: SCU double-rate clock
- scu_supply_clk: SCU supply clock

Without these clocks enabled, the SRC module cannot operate on RZ/G3E.
Add support for the shared SCU reset controller used by the SRC modules
on the Renesas RZ/G3E SoC. All SRC instances are gated by the same "scu"
reset line.

Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
---

Changes:

v2: No changes

sound/soc/renesas/rcar/rsnd.h | 7 ++++++
sound/soc/renesas/rcar/src.c | 45 +++++++++++++++++++++++++++++++++--
2 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/sound/soc/renesas/rcar/rsnd.h b/sound/soc/renesas/rcar/rsnd.h
index 2c5738926093..8700b39b535e 100644
--- a/sound/soc/renesas/rcar/rsnd.h
+++ b/sound/soc/renesas/rcar/rsnd.h
@@ -632,6 +632,13 @@ struct rsnd_priv {
struct clk *audmapp_clk;
struct reset_control *audmapp_rstc;

+ /*
+ * Below values will be filled in rsnd_src_probe()
+ */
+ struct clk *clk_scu;
+ struct clk *clk_scu_x2;
+ struct clk *clk_scu_supply;
+
spinlock_t lock;
unsigned int ssiu_busif_count;
unsigned long flags;
diff --git a/sound/soc/renesas/rcar/src.c b/sound/soc/renesas/rcar/src.c
index 8b58cc20e7a8..e1f609589406 100644
--- a/sound/soc/renesas/rcar/src.c
+++ b/sound/soc/renesas/rcar/src.c
@@ -516,6 +516,7 @@ static int rsnd_src_init(struct rsnd_mod *mod,
struct rsnd_priv *priv)
{
struct rsnd_src *src = rsnd_mod_to_src(mod);
+ struct device *dev = rsnd_priv_to_dev(priv);
int ret;

/* reset sync convert_rate */
@@ -526,6 +527,12 @@ static int rsnd_src_init(struct rsnd_mod *mod,
if (ret < 0)
return ret;

+ ret = clk_prepare_enable(priv->clk_scu_supply);
+ if (ret) {
+ dev_err(dev, "Cannot enable scu_supply_clk\n");
+ return ret;
+ }
+
rsnd_src_activation(mod);

rsnd_src_init_convert_rate(io, mod);
@@ -549,6 +556,8 @@ static int rsnd_src_quit(struct rsnd_mod *mod,
src->sync.val =
src->current_sync_rate = 0;

+ clk_disable_unprepare(priv->clk_scu_supply);
+
return 0;
}

@@ -711,8 +720,9 @@ struct rsnd_mod *rsnd_src_mod_get(struct rsnd_priv *priv, int id)

int rsnd_src_probe(struct rsnd_priv *priv)
{
- struct device_node *node;
struct device *dev = rsnd_priv_to_dev(priv);
+ struct reset_control *rstc;
+ struct device_node *node;
struct rsnd_src *src;
struct clk *clk;
char name[RSND_SRC_NAME_SIZE];
@@ -737,6 +747,27 @@ int rsnd_src_probe(struct rsnd_priv *priv)
priv->src_nr = nr;
priv->src = src;

+ priv->clk_scu = devm_clk_get_optional_enabled(dev, "scu");
+ if (IS_ERR(priv->clk_scu)) {
+ ret = dev_err_probe(dev, PTR_ERR(priv->clk_scu),
+ "failed to get scu clock\n");
+ goto rsnd_src_probe_done;
+ }
+
+ priv->clk_scu_x2 = devm_clk_get_optional_enabled(dev, "scu_x2");
+ if (IS_ERR(priv->clk_scu_x2)) {
+ ret = dev_err_probe(dev, PTR_ERR(priv->clk_scu_x2),
+ "failed to get scu_x2 clock\n");
+ goto rsnd_src_probe_done;
+ }
+
+ priv->clk_scu_supply = devm_clk_get_optional(dev, "scu_supply");
+ if (IS_ERR(priv->clk_scu_supply)) {
+ ret = dev_err_probe(dev, PTR_ERR(priv->clk_scu_supply),
+ "failed to get scu_supply clock\n");
+ goto rsnd_src_probe_done;
+ }
+
i = 0;
for_each_child_of_node_scoped(node, np) {
if (!of_device_is_available(np))
@@ -759,6 +790,16 @@ int rsnd_src_probe(struct rsnd_priv *priv)
goto rsnd_src_probe_done;
}

+ /*
+ * RZ/G3E uses a shared SCU reset controller for all SRC modules.
+ * R-Car platforms typically don't have SRC reset controls.
+ */
+ rstc = devm_reset_control_get_optional_shared(dev, "scu");
+ if (IS_ERR(rstc)) {
+ ret = PTR_ERR(rstc);
+ goto rsnd_src_probe_done;
+ }
+
clk = devm_clk_get(dev, name);
if (IS_ERR(clk)) {
ret = PTR_ERR(clk);
@@ -766,7 +807,7 @@ int rsnd_src_probe(struct rsnd_priv *priv)
}

ret = rsnd_mod_init(priv, rsnd_mod_get(src),
- &rsnd_src_ops, clk, NULL, RSND_MOD_SRC, i);
+ &rsnd_src_ops, clk, rstc, RSND_MOD_SRC, i);
if (ret)
goto rsnd_src_probe_done;

--
2.25.1