[PATCH v7 06/18] ASoC: rsnd: Add audmapp clock and reset support for RZ/G3E

[John Madieu]

RZ/G3E requires additional audmapp clock and reset lines for
Audio DMA-PP operation.

Add global audmapp clock/reset management in rsnd_dma_probe()
using optional APIs to remain transparent to other platforms.

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

Changes:

v7:
 - Fix the "audmacpp" spelling to "audmapp" in the patch subject
   and commit message, matching the clock/reset name and the rest
   of the driver. No code change.

v6:
 - Enable the audmapp clock before deasserting the audmapp reset
   so the block sees a stable clock on the way out of reset.
 - Drop redundant braces around single-statement if blocks (style).

v5:
 - Add comment on audmapp clock/reset acquisition clarifying these
   are optional and transparent to platforms that don't have them
   in DT, per Kuninori's request.
 - Drop spurious blank line added to struct rsnd_priv in rsnd.h.

v4:
 - Move audmapp_clk and audmapp_rstc from struct rsnd_priv into
   struct rsnd_dma_ctrl.

v3: No changes
v2: No changes

 sound/soc/renesas/rcar/dma.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/sound/soc/renesas/rcar/dma.c b/sound/soc/renesas/rcar/dma.c
index 68c859897e68..d52cada711e5 100644
--- a/sound/soc/renesas/rcar/dma.c
+++ b/sound/soc/renesas/rcar/dma.c
@@ -47,6 +47,9 @@ struct rsnd_dma_ctrl {
 	phys_addr_t ppres;
 	int dmaen_num;
 	int dmapp_num;
+	/* RZ/G3E: Audio DMAC peri-peri clock and reset */
+	struct clk *audmapp_clk;
+	struct reset_control *audmapp_rstc;
 };
 
 #define rsnd_priv_to_dmac(p)	((struct rsnd_dma_ctrl *)(p)->dma)
@@ -870,6 +873,25 @@ int rsnd_dma_probe(struct rsnd_priv *priv)
 		return 0; /* it will be PIO mode */
 	}
 
+	/*
+	 * Audio DMAC peri-peri clock and reset for RZ/G3E.
+	 * These use optional APIs, so they gracefully return NULL
+	 * (no error) on platforms whose DT does not provide them.
+	 *
+	 * Enable the clock first so the block sees a stable clock on
+	 * the way out of reset, then deassert the reset line.
+	 */
+	dmac->audmapp_clk = devm_clk_get_optional_enabled(dev, "audmapp");
+	if (IS_ERR(dmac->audmapp_clk))
+		return dev_err_probe(dev, PTR_ERR(dmac->audmapp_clk),
+				     "failed to get audmapp clock\n");
+
+	dmac->audmapp_rstc =
+		devm_reset_control_get_optional_exclusive_deasserted(dev, "audmapp");
+	if (IS_ERR(dmac->audmapp_rstc))
+		return dev_err_probe(dev, PTR_ERR(dmac->audmapp_rstc),
+				     "failed to get audmapp reset\n");
+
 	dmac->dmapp_num = 0;
 	dmac->ppres  = res->start;
 	dmac->ppbase = devm_ioremap_resource(dev, res);
-- 
2.25.1