[PATCH v6 16/16] ASoC: rsnd: Add system suspend/resume support

[John Madieu <john.madieu.xa@bp.renesas.com>]

Add system suspend/resume support for the ASoC rsnd driver, required
for RZ/G3E platforms. Distribute the per-module suspend/resume work
across the relevant files (adg.c, ssi.c, ssiu.c, src.c, ctu.c, mix.c,
dvc.c, dma.c) rather than centralising it in core.c.

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

Changes:

v6:
 - rsnd_dma_suspend()/_resume(): respect the audmapp probe
   ordering. On suspend, assert the reset before disabling the
   clock; on resume, enable the clock before deasserting the
   reset.
 - rsnd_src_suspend()/_resume(): cache src_ctrl in a local and
   add an "if (!src_ctrl) return;" early-out so platforms that
   do not instantiate the SRC subsystem are safe.

v5: No changes

v4:
 - Absorb rsnd_adg_mod_get() helper directly instead of a
   separate preparatory patch.
 - Distribute suspend/resume declarations into their respective
   IP sections in rsnd.h.

v3: No changes
v2:
 - Distribute suspend/resume into per-module files (ssi.c,
   ssiu.c, src.c, ctu.c, mix.c, dvc.c, adg.c, dma.c) instead of
   monolithic loops in core.c, following Morimoto-san's
   architecture suggestion.

 sound/soc/renesas/rcar/adg.c  | 26 +++++++++++++++++++++
 sound/soc/renesas/rcar/core.c | 43 +++++++++++++++++++++++++++++++++--
 sound/soc/renesas/rcar/ctu.c  | 20 ++++++++++++++++
 sound/soc/renesas/rcar/dma.c  | 22 ++++++++++++++++++
 sound/soc/renesas/rcar/dvc.c  | 20 ++++++++++++++++
 sound/soc/renesas/rcar/mix.c  | 20 ++++++++++++++++
 sound/soc/renesas/rcar/rsnd.h | 18 +++++++++++++++
 sound/soc/renesas/rcar/src.c  | 34 +++++++++++++++++++++++++++
 sound/soc/renesas/rcar/ssi.c  | 20 ++++++++++++++++
 sound/soc/renesas/rcar/ssiu.c | 20 ++++++++++++++++
 10 files changed, 241 insertions(+), 2 deletions(-)

diff --git a/sound/soc/renesas/rcar/adg.c b/sound/soc/renesas/rcar/adg.c
index 203298b63b76..3d8fd66be648 100644
--- a/sound/soc/renesas/rcar/adg.c
+++ b/sound/soc/renesas/rcar/adg.c
@@ -915,3 +915,29 @@ void rsnd_adg_remove(struct rsnd_priv *priv)
 	/* It should be called after rsnd_adg_clk_disable() */
 	rsnd_adg_null_clk_clean(priv);
 }
+
+static struct rsnd_mod *rsnd_adg_mod_get(struct rsnd_priv *priv)
+{
+	struct rsnd_adg *adg = rsnd_priv_to_adg(priv);
+
+	if (!adg)
+		return NULL;
+
+	return rsnd_mod_get(adg);
+}
+
+void rsnd_adg_suspend(struct rsnd_priv *priv)
+{
+	struct rsnd_mod *mod = rsnd_adg_mod_get(priv);
+
+	if (mod)
+		rsnd_suspend_clk_reset(mod->clk, mod->rstc);
+}
+
+void rsnd_adg_resume(struct rsnd_priv *priv)
+{
+	struct rsnd_mod *mod = rsnd_adg_mod_get(priv);
+
+	if (mod)
+		rsnd_resume_clk_reset(mod->clk, mod->rstc);
+}
diff --git a/sound/soc/renesas/rcar/core.c b/sound/soc/renesas/rcar/core.c
index 679c833fd001..26cd908299e6 100644
--- a/sound/soc/renesas/rcar/core.c
+++ b/sound/soc/renesas/rcar/core.c
@@ -963,7 +963,8 @@ static int rsnd_soc_hw_rule_channels(struct snd_pcm_hw_params *params,
 static const struct snd_pcm_hardware rsnd_pcm_hardware = {
 	.info =		SNDRV_PCM_INFO_INTERLEAVED	|
 			SNDRV_PCM_INFO_MMAP		|
-			SNDRV_PCM_INFO_MMAP_VALID,
+			SNDRV_PCM_INFO_MMAP_VALID	|
+			SNDRV_PCM_INFO_RESUME,
 	.buffer_bytes_max	= 64 * 1024,
 	.period_bytes_min	= 32,
 	.period_bytes_max	= 8192,
@@ -2160,11 +2161,35 @@ static void rsnd_remove(struct platform_device *pdev)
 		remove_func[i](priv);
 }
 
+void rsnd_suspend_clk_reset(struct clk *clk, struct reset_control *rstc)
+{
+	clk_unprepare(clk);
+	reset_control_assert(rstc);
+}
+
+void rsnd_resume_clk_reset(struct clk *clk, struct reset_control *rstc)
+{
+	reset_control_deassert(rstc);
+	clk_prepare(clk);
+}
+
 static int rsnd_suspend(struct device *dev)
 {
 	struct rsnd_priv *priv = dev_get_drvdata(dev);
 
+	/*
+	 * Reverse order of probe:
+	 * ADG -> DVC -> MIX -> CTU -> SRC -> SSIU -> SSI -> DMA
+	 */
 	rsnd_adg_clk_disable(priv);
+	rsnd_adg_suspend(priv);
+	rsnd_dvc_suspend(priv);
+	rsnd_mix_suspend(priv);
+	rsnd_ctu_suspend(priv);
+	rsnd_src_suspend(priv);
+	rsnd_ssiu_suspend(priv);
+	rsnd_ssi_suspend(priv);
+	rsnd_dma_suspend(priv);
 
 	return 0;
 }
@@ -2173,7 +2198,21 @@ static int rsnd_resume(struct device *dev)
 {
 	struct rsnd_priv *priv = dev_get_drvdata(dev);
 
-	return rsnd_adg_clk_enable(priv);
+	/*
+	 * Same order as probe:
+	 * DMA -> SSI -> SSIU -> SRC -> CTU -> MIX -> DVC -> ADG
+	 */
+	rsnd_dma_resume(priv);
+	rsnd_ssi_resume(priv);
+	rsnd_ssiu_resume(priv);
+	rsnd_src_resume(priv);
+	rsnd_ctu_resume(priv);
+	rsnd_mix_resume(priv);
+	rsnd_dvc_resume(priv);
+	rsnd_adg_resume(priv);
+	rsnd_adg_clk_enable(priv);
+
+	return 0;
 }
 
 static const struct dev_pm_ops rsnd_pm_ops = {
diff --git a/sound/soc/renesas/rcar/ctu.c b/sound/soc/renesas/rcar/ctu.c
index 293b0eec1ded..7db0fb3612bc 100644
--- a/sound/soc/renesas/rcar/ctu.c
+++ b/sound/soc/renesas/rcar/ctu.c
@@ -378,3 +378,23 @@ void rsnd_ctu_remove(struct rsnd_priv *priv)
 		rsnd_mod_quit(rsnd_mod_get(ctu));
 	}
 }
+
+void rsnd_ctu_suspend(struct rsnd_priv *priv)
+{
+	struct rsnd_ctu *ctu;
+	int i;
+
+	for_each_rsnd_ctu(ctu, priv, i)
+		rsnd_suspend_clk_reset(rsnd_mod_get(ctu)->clk,
+				       rsnd_mod_get(ctu)->rstc);
+}
+
+void rsnd_ctu_resume(struct rsnd_priv *priv)
+{
+	struct rsnd_ctu *ctu;
+	int i;
+
+	for_each_rsnd_ctu(ctu, priv, i)
+		rsnd_resume_clk_reset(rsnd_mod_get(ctu)->clk,
+				      rsnd_mod_get(ctu)->rstc);
+}
diff --git a/sound/soc/renesas/rcar/dma.c b/sound/soc/renesas/rcar/dma.c
index 0bca0b303191..0bf97a12a9a7 100644
--- a/sound/soc/renesas/rcar/dma.c
+++ b/sound/soc/renesas/rcar/dma.c
@@ -1035,3 +1035,25 @@ int rsnd_dma_probe(struct rsnd_priv *priv)
 	/* dummy mem mod for debug */
 	return rsnd_mod_init(NULL, &mem, &mem_ops, NULL, NULL, 0, 0);
 }
+
+void rsnd_dma_suspend(struct rsnd_priv *priv)
+{
+	struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);
+
+	if (dmac) {
+		/* Mirror probe (which enables clk before deasserting reset) */
+		rsnd_suspend_clk_reset(NULL, dmac->audmapp_rstc);
+		clk_disable_unprepare(dmac->audmapp_clk);
+	}
+}
+
+void rsnd_dma_resume(struct rsnd_priv *priv)
+{
+	struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);
+
+	if (dmac) {
+		/* Clock must be stable before reset is deasserted */
+		clk_prepare_enable(dmac->audmapp_clk);
+		rsnd_resume_clk_reset(NULL, dmac->audmapp_rstc);
+	}
+}
diff --git a/sound/soc/renesas/rcar/dvc.c b/sound/soc/renesas/rcar/dvc.c
index 26f80d542da8..7601dfb0810a 100644
--- a/sound/soc/renesas/rcar/dvc.c
+++ b/sound/soc/renesas/rcar/dvc.c
@@ -381,3 +381,23 @@ void rsnd_dvc_remove(struct rsnd_priv *priv)
 		rsnd_mod_quit(rsnd_mod_get(dvc));
 	}
 }
+
+void rsnd_dvc_suspend(struct rsnd_priv *priv)
+{
+	struct rsnd_dvc *dvc;
+	int i;
+
+	for_each_rsnd_dvc(dvc, priv, i)
+		rsnd_suspend_clk_reset(rsnd_mod_get(dvc)->clk,
+				       rsnd_mod_get(dvc)->rstc);
+}
+
+void rsnd_dvc_resume(struct rsnd_priv *priv)
+{
+	struct rsnd_dvc *dvc;
+	int i;
+
+	for_each_rsnd_dvc(dvc, priv, i)
+		rsnd_resume_clk_reset(rsnd_mod_get(dvc)->clk,
+				      rsnd_mod_get(dvc)->rstc);
+}
diff --git a/sound/soc/renesas/rcar/mix.c b/sound/soc/renesas/rcar/mix.c
index 9ffa591aa4a4..c4da4c4bedb3 100644
--- a/sound/soc/renesas/rcar/mix.c
+++ b/sound/soc/renesas/rcar/mix.c
@@ -345,3 +345,23 @@ void rsnd_mix_remove(struct rsnd_priv *priv)
 		rsnd_mod_quit(rsnd_mod_get(mix));
 	}
 }
+
+void rsnd_mix_suspend(struct rsnd_priv *priv)
+{
+	struct rsnd_mix *mix;
+	int i;
+
+	for_each_rsnd_mix(mix, priv, i)
+		rsnd_suspend_clk_reset(rsnd_mod_get(mix)->clk,
+				       rsnd_mod_get(mix)->rstc);
+}
+
+void rsnd_mix_resume(struct rsnd_priv *priv)
+{
+	struct rsnd_mix *mix;
+	int i;
+
+	for_each_rsnd_mix(mix, priv, i)
+		rsnd_resume_clk_reset(rsnd_mod_get(mix)->clk,
+				      rsnd_mod_get(mix)->rstc);
+}
diff --git a/sound/soc/renesas/rcar/rsnd.h b/sound/soc/renesas/rcar/rsnd.h
index 1e4bc8a6c55c..7c9b2d064d50 100644
--- a/sound/soc/renesas/rcar/rsnd.h
+++ b/sound/soc/renesas/rcar/rsnd.h
@@ -267,6 +267,8 @@ u32 rsnd_get_busif_shift(struct rsnd_dai_stream *io, struct rsnd_mod *mod);
 int rsnd_dma_attach(struct rsnd_dai_stream *io,
 		    struct rsnd_mod *mod, struct rsnd_mod **dma_mod);
 int rsnd_dma_probe(struct rsnd_priv *priv);
+void rsnd_dma_suspend(struct rsnd_priv *priv);
+void rsnd_dma_resume(struct rsnd_priv *priv);
 struct dma_chan *rsnd_dma_request_channel(struct device_node *of_node, char *name,
 					  struct rsnd_mod *mod, char *x);
 
@@ -429,6 +431,8 @@ int rsnd_mod_init(struct rsnd_priv *priv,
 		  enum rsnd_mod_type type,
 		  int id);
 void rsnd_mod_quit(struct rsnd_mod *mod);
+void rsnd_suspend_clk_reset(struct clk *clk, struct reset_control *rstc);
+void rsnd_resume_clk_reset(struct clk *clk, struct reset_control *rstc);
 struct dma_chan *rsnd_mod_dma_req(struct rsnd_dai_stream *io,
 				  struct rsnd_mod *mod);
 void rsnd_mod_interrupt(struct rsnd_mod *mod,
@@ -625,6 +629,8 @@ int rsnd_adg_ssi_clk_stop(struct rsnd_mod *ssi_mod);
 int rsnd_adg_ssi_clk_try_start(struct rsnd_mod *ssi_mod, unsigned int rate);
 int rsnd_adg_probe(struct rsnd_priv *priv);
 void rsnd_adg_remove(struct rsnd_priv *priv);
+void rsnd_adg_suspend(struct rsnd_priv *priv);
+void rsnd_adg_resume(struct rsnd_priv *priv);
 int rsnd_adg_set_src_timesel_gen2(struct rsnd_mod *src_mod,
 				  struct rsnd_dai_stream *io,
 				  unsigned int in_rate,
@@ -822,6 +828,8 @@ extern const char * const volume_ramp_rate[];
  */
 int rsnd_ssi_probe(struct rsnd_priv *priv);
 void rsnd_ssi_remove(struct rsnd_priv *priv);
+void rsnd_ssi_suspend(struct rsnd_priv *priv);
+void rsnd_ssi_resume(struct rsnd_priv *priv);
 struct rsnd_mod *rsnd_ssi_mod_get(struct rsnd_priv *priv, int id);
 int rsnd_ssi_use_busif(struct rsnd_dai_stream *io);
 u32 rsnd_ssi_multi_secondaries_runtime(struct rsnd_dai_stream *io);
@@ -845,6 +853,8 @@ int rsnd_ssiu_attach(struct rsnd_dai_stream *io,
 		     struct rsnd_mod *mod);
 int rsnd_ssiu_probe(struct rsnd_priv *priv);
 void rsnd_ssiu_remove(struct rsnd_priv *priv);
+void rsnd_ssiu_suspend(struct rsnd_priv *priv);
+void rsnd_ssiu_resume(struct rsnd_priv *priv);
 void rsnd_parse_connect_ssiu(struct rsnd_dai *rdai,
 			     struct device_node *playback,
 			     struct device_node *capture);
@@ -856,6 +866,8 @@ bool rsnd_ssiu_busif_err_status_clear(struct rsnd_mod *mod);
  */
 int rsnd_src_probe(struct rsnd_priv *priv);
 void rsnd_src_remove(struct rsnd_priv *priv);
+void rsnd_src_suspend(struct rsnd_priv *priv);
+void rsnd_src_resume(struct rsnd_priv *priv);
 struct rsnd_mod *rsnd_src_mod_get(struct rsnd_priv *priv, int id);
 
 #define rsnd_src_get_in_rate(priv, io) rsnd_src_get_rate(priv, io, 1)
@@ -875,6 +887,8 @@ unsigned int rsnd_src_get_rate(struct rsnd_priv *priv,
  */
 int rsnd_ctu_probe(struct rsnd_priv *priv);
 void rsnd_ctu_remove(struct rsnd_priv *priv);
+void rsnd_ctu_suspend(struct rsnd_priv *priv);
+void rsnd_ctu_resume(struct rsnd_priv *priv);
 struct rsnd_mod *rsnd_ctu_mod_get(struct rsnd_priv *priv, int id);
 #define rsnd_ctu_of_node(priv) rsnd_parse_of_node(priv, RSND_NODE_CTU)
 #define rsnd_parse_connect_ctu(rdai, playback, capture)			\
@@ -887,6 +901,8 @@ struct rsnd_mod *rsnd_ctu_mod_get(struct rsnd_priv *priv, int id);
  */
 int rsnd_mix_probe(struct rsnd_priv *priv);
 void rsnd_mix_remove(struct rsnd_priv *priv);
+void rsnd_mix_suspend(struct rsnd_priv *priv);
+void rsnd_mix_resume(struct rsnd_priv *priv);
 struct rsnd_mod *rsnd_mix_mod_get(struct rsnd_priv *priv, int id);
 #define rsnd_mix_of_node(priv) rsnd_parse_of_node(priv, RSND_NODE_MIX)
 #define rsnd_parse_connect_mix(rdai, playback, capture)			\
@@ -899,6 +915,8 @@ struct rsnd_mod *rsnd_mix_mod_get(struct rsnd_priv *priv, int id);
  */
 int rsnd_dvc_probe(struct rsnd_priv *priv);
 void rsnd_dvc_remove(struct rsnd_priv *priv);
+void rsnd_dvc_suspend(struct rsnd_priv *priv);
+void rsnd_dvc_resume(struct rsnd_priv *priv);
 struct rsnd_mod *rsnd_dvc_mod_get(struct rsnd_priv *priv, int id);
 #define rsnd_dvc_of_node(priv) rsnd_parse_of_node(priv, RSND_NODE_DVC)
 #define rsnd_parse_connect_dvc(rdai, playback, capture)			\
diff --git a/sound/soc/renesas/rcar/src.c b/sound/soc/renesas/rcar/src.c
index 0237b5d2e79e..a84425587978 100644
--- a/sound/soc/renesas/rcar/src.c
+++ b/sound/soc/renesas/rcar/src.c
@@ -834,3 +834,37 @@ void rsnd_src_remove(struct rsnd_priv *priv)
 		rsnd_mod_quit(rsnd_mod_get(src));
 	}
 }
+
+void rsnd_src_suspend(struct rsnd_priv *priv)
+{
+	struct rsnd_src_ctrl *src_ctrl = rsnd_priv_to_src_ctrl(priv);
+	struct rsnd_src *src;
+	int i;
+
+	if (!src_ctrl)
+		return;
+
+	for_each_rsnd_src(src, priv, i)
+		rsnd_suspend_clk_reset(rsnd_mod_get(src)->clk,
+				       rsnd_mod_get(src)->rstc);
+
+	clk_disable_unprepare(src_ctrl->scu_x2);
+	clk_disable_unprepare(src_ctrl->scu);
+}
+
+void rsnd_src_resume(struct rsnd_priv *priv)
+{
+	struct rsnd_src_ctrl *src_ctrl = rsnd_priv_to_src_ctrl(priv);
+	struct rsnd_src *src;
+	int i;
+
+	if (!src_ctrl)
+		return;
+
+	clk_prepare_enable(src_ctrl->scu);
+	clk_prepare_enable(src_ctrl->scu_x2);
+
+	for_each_rsnd_src(src, priv, i)
+		rsnd_resume_clk_reset(rsnd_mod_get(src)->clk,
+				      rsnd_mod_get(src)->rstc);
+}
diff --git a/sound/soc/renesas/rcar/ssi.c b/sound/soc/renesas/rcar/ssi.c
index 007a7c91d470..2fa76a079982 100644
--- a/sound/soc/renesas/rcar/ssi.c
+++ b/sound/soc/renesas/rcar/ssi.c
@@ -1257,3 +1257,23 @@ void rsnd_ssi_remove(struct rsnd_priv *priv)
 		rsnd_mod_quit(rsnd_mod_get(ssi));
 	}
 }
+
+void rsnd_ssi_suspend(struct rsnd_priv *priv)
+{
+	struct rsnd_ssi *ssi;
+	int i;
+
+	for_each_rsnd_ssi(ssi, priv, i)
+		rsnd_suspend_clk_reset(rsnd_mod_get(ssi)->clk,
+				       rsnd_mod_get(ssi)->rstc);
+}
+
+void rsnd_ssi_resume(struct rsnd_priv *priv)
+{
+	struct rsnd_ssi *ssi;
+	int i;
+
+	for_each_rsnd_ssi(ssi, priv, i)
+		rsnd_resume_clk_reset(rsnd_mod_get(ssi)->clk,
+				      rsnd_mod_get(ssi)->rstc);
+}
diff --git a/sound/soc/renesas/rcar/ssiu.c b/sound/soc/renesas/rcar/ssiu.c
index 8fb0ec5dc791..60b58096531d 100644
--- a/sound/soc/renesas/rcar/ssiu.c
+++ b/sound/soc/renesas/rcar/ssiu.c
@@ -630,3 +630,23 @@ void rsnd_ssiu_remove(struct rsnd_priv *priv)
 		rsnd_mod_quit(rsnd_mod_get(ssiu));
 	}
 }
+
+void rsnd_ssiu_suspend(struct rsnd_priv *priv)
+{
+	struct rsnd_ssiu *ssiu;
+	int i;
+
+	for_each_rsnd_ssiu(ssiu, priv, i)
+		rsnd_suspend_clk_reset(rsnd_mod_get(ssiu)->clk,
+				       rsnd_mod_get(ssiu)->rstc);
+}
+
+void rsnd_ssiu_resume(struct rsnd_priv *priv)
+{
+	struct rsnd_ssiu *ssiu;
+	int i;
+
+	for_each_rsnd_ssiu(ssiu, priv, i)
+		rsnd_resume_clk_reset(rsnd_mod_get(ssiu)->clk,
+				      rsnd_mod_get(ssiu)->rstc);
+}
-- 
2.25.1