ASoC: rockchip: i2s: Adds properties to specify playback/capture capability

- 'rockchip,playback-only': support playback only.
- 'rockchip,capture-only': support capture only.

Change-Id: I0daee4dc5bda8bacc63201972b57c8d401fb8703
Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>

Documentation/devicetree/bindings/sound/rockchip,i2s-tdm.txt

@@ -28,6 +28,8 @@ Required properties:
   register pcm dmaengine, only just register dai. if the dai is part of multi-dais,
   the property should be present. Please refer to rockchip,multidais.txt about
   multi-dais usage.
+- rockchip,playback-only: Specify that the controller only has playback capability.
+- rockchip,capture-only: Specify that the controller only has capture capability.
 
 Optional properties:
 - rockchip,i2s-rx-route: This is a variable length array, that shows the mapping

Documentation/devicetree/bindings/sound/rockchip-i2s.txt

@@ -43,6 +43,8 @@ Required properties:
   register pcm dmaengine, only just register dai. if the dai is part of multi-dais,
   the property should be present. Please refer to rockchip,multidais.txt about
   multi-dais usage.
+- rockchip,playback-only: Specify that the controller only has playback capability.
+- rockchip,capture-only: Specify that the controller only has capture capability.
 
 Required properties for controller which support multi channels
 playback/capture:

sound/soc/rockchip/rockchip_i2s.c

@@ -705,6 +705,11 @@ static int rockchip_i2s_probe(struct platform_device *pdev)
 			soc_dai->capture.channels_max = val;
 	}
 
+	if (of_property_read_bool(node, "rockchip,playback-only"))
+		soc_dai->capture.channels_min = 0;
+	else if (of_property_read_bool(node, "rockchip,capture-only"))
+		soc_dai->playback.channels_min = 0;
+
 	i2s->bclk_fs = 64;
 	if (!of_property_read_u32(node, "rockchip,bclk-fs", &val)) {
 		if ((val >= 32) && (val % 2 == 0))

sound/soc/rockchip/rockchip_i2s_tdm.c

@@ -1370,6 +1370,11 @@ static int rockchip_i2s_tdm_probe(struct platform_device *pdev)
 		}
 	}
 
+	if (of_property_read_bool(node, "rockchip,playback-only"))
+		soc_dai->capture.channels_min = 0;
+	else if (of_property_read_bool(node, "rockchip,capture-only"))
+		soc_dai->playback.channels_min = 0;
+
 	i2s_tdm->grf = syscon_regmap_lookup_by_phandle(node, "rockchip,grf");
 	if (IS_ERR(i2s_tdm->grf))
 		return PTR_ERR(i2s_tdm->grf);