drm/vc4: hdmi: Add audio-related callbacks

The audio configuration has changed for the BCM2711, with notably a
different parent clock and a different channel configuration.

Make that modular to be able to support the BCM2711.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://patchwork.freedesktop.org/patch/msgid/85a8ca721c2d800be758c55870cea98536749680.1599120059.git-series.maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -611,10 +611,22 @@ static const struct drm_encoder_helper_funcs vc4_hdmi_encoder_helper_funcs = {
 	.enable = vc4_hdmi_encoder_enable,
 };
 
+static u32 vc4_hdmi_channel_map(struct vc4_hdmi *vc4_hdmi, u32 channel_mask)
+{
+	int i;
+	u32 channel_map = 0;
+
+	for (i = 0; i < 8; i++) {
+		if (channel_mask & BIT(i))
+			channel_map |= i << (3 * i);
+	}
+	return channel_map;
+}
+
 /* HDMI audio codec callbacks */
 static void vc4_hdmi_audio_set_mai_clock(struct vc4_hdmi *vc4_hdmi)
 {
-	u32 hsm_clock = clk_get_rate(vc4_hdmi->hsm_clock);
+	u32 hsm_clock = clk_get_rate(vc4_hdmi->audio_clock);
 	unsigned long n, m;
 
 	rational_best_approximation(hsm_clock, vc4_hdmi->audio.samplerate,
@@ -733,7 +745,7 @@ static int vc4_hdmi_audio_hw_params(struct snd_pcm_substream *substream,
 	struct vc4_hdmi *vc4_hdmi = dai_to_hdmi(dai);
 	struct device *dev = &vc4_hdmi->pdev->dev;
 	u32 audio_packet_config, channel_mask;
-	u32 channel_map, i;
+	u32 channel_map;
 
 	if (substream != vc4_hdmi->audio.substream)
 		return -EINVAL;
@@ -785,12 +797,7 @@ static int vc4_hdmi_audio_hw_params(struct snd_pcm_substream *substream,
 		   VC4_HDMI_MAI_CONFIG_BIT_REVERSE |
 		   VC4_SET_FIELD(channel_mask, VC4_HDMI_MAI_CHANNEL_MASK));
 
-	channel_map = 0;
-	for (i = 0; i < 8; i++) {
-		if (channel_mask & BIT(i))
-			channel_map |= i << (3 * i);
-	}
-
+	channel_map = vc4_hdmi->variant->channel_map(vc4_hdmi, channel_mask);
 	HDMI_WRITE(HDMI_MAI_CHANNEL_MAP, channel_map);
 	HDMI_WRITE(HDMI_AUDIO_PACKET_CONFIG, audio_packet_config);
 	vc4_hdmi_set_n_cts(vc4_hdmi);
@@ -1342,6 +1349,7 @@ static int vc4_hdmi_init_resources(struct vc4_hdmi *vc4_hdmi)
 		DRM_ERROR("Failed to get HDMI state machine clock\n");
 		return PTR_ERR(vc4_hdmi->hsm_clock);
 	}
+	vc4_hdmi->audio_clock = vc4_hdmi->hsm_clock;
 
 	return 0;
 }
@@ -1507,6 +1515,7 @@ static const struct vc4_hdmi_variant bcm2835_variant = {
 	.phy_disable		= vc4_hdmi_phy_disable,
 	.phy_rng_enable		= vc4_hdmi_phy_rng_enable,
 	.phy_rng_disable	= vc4_hdmi_phy_rng_disable,
+	.channel_map		= vc4_hdmi_channel_map,
 };
 
 static const struct of_device_id vc4_hdmi_dt_match[] = {

drivers/gpu/drm/vc4/vc4_hdmi.h

@@ -72,6 +72,9 @@ struct vc4_hdmi_variant {
 
 	/* Callback to disable the RNG in the PHY */
 	void (*phy_rng_disable)(struct vc4_hdmi *vc4_hdmi);
+
+	/* Callback to get channel map */
+	u32 (*channel_map)(struct vc4_hdmi *vc4_hdmi, u32 channel_mask);
 };
 
 /* HDMI audio information */
@@ -112,6 +115,7 @@ struct vc4_hdmi {
 
 	struct clk *pixel_clock;
 	struct clk *hsm_clock;
+	struct clk *audio_clock;
 
 	struct debugfs_regset32 hdmi_regset;
 	struct debugfs_regset32 hd_regset;