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From:   Cheng-Yi Chiang <cychiang@chromium.org>
To:     linux-kernel@vger.kernel.org
Cc:     alsa-devel@alsa-project.org, linux-arm-kernel@lists.infradead.org,
        linux-rockchip@lists.infradead.org, a.hajda@samsung.com,
        Laurent.pinchart@ideasonboard.com, airlied@linux.ie,
        daniel@ffwll.ch, kuninori.morimoto.gx@renesas.com,
        sam@ravnborg.org, cychiang@chromium.org, dianders@chromium.org,
        dgreid@chromium.org, tzungbi@chromium.org,
        zhengxing@rock-chips.com, cain.cai@rock-chips.com,
        eddie.cai@rock-chips.com, jeffy.chen@rock-chips.com,
        kuankuan.y@gmail.com, enric.balletbo@collabora.com,
        dri-devel@lists.freedesktop.org, jernej.skrabec@siol.net,
        jonas@kwiboo.se, Yakir Yang <ykk@rock-chips.com>
Subject: [PATCH v2] drm: bridge/dw_hdmi: add audio sample channel status setting
Date:   Thu,  5 Sep 2019 17:43:25 +0800
Message-Id: <20190905094325.33156-1-cychiang@chromium.org>
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Sender: linux-kernel-owner@vger.kernel.org
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From: Yakir Yang <ykk@rock-chips.com>

When transmitting IEC60985 linear PCM audio, we configure the
Aduio Sample Channel Status information of all the channel
status bits in the IEC60958 frame.
Refer to 60958-3 page 10 for frequency, original frequency, and
wordlength setting.

This fix the issue that audio does not come out on some monitors
(e.g. LG 22CV241)

Note that these registers are only for interfaces:
I2S audio interface, General Purpose Audio (GPA), or AHB audio DMA
(AHBAUDDMA).
For S/PDIF interface this information comes from the stream.

Currently this function dw_hdmi_set_channel_status is only called
from dw-hdmi-i2s-audio in I2S setup.

Signed-off-by: Yakir Yang <ykk@rock-chips.com>
Signed-off-by: Cheng-Yi Chiang <cychiang@chromium.org>
---
 Original patch by Yakir Yang is at

 https://lore.kernel.org/patchwork/patch/539653/

 Change from v1 to v2:
 1. Remove the version check because this will only be called by
    dw-hdmi-i2s-audio, and the registers are available in I2S setup.
 2. Set these registers in dw_hdmi_i2s_hw_params.
 3. Fix the sample width setting so it can use 16 or 24 bits.

 .../drm/bridge/synopsys/dw-hdmi-i2s-audio.c   |  1 +
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c     | 70 +++++++++++++++++++
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.h     | 20 ++++++
 include/drm/bridge/dw_hdmi.h                  |  2 +
 4 files changed, 93 insertions(+)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
index 34d8e837555f..b801a28b0f17 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
@@ -102,6 +102,7 @@ static int dw_hdmi_i2s_hw_params(struct device *dev, void *data,
 	}
 
 	dw_hdmi_set_sample_rate(hdmi, hparms->sample_rate);
+	dw_hdmi_set_channel_status(hdmi, hparms->sample_width);
 	dw_hdmi_set_channel_count(hdmi, hparms->channels);
 	dw_hdmi_set_channel_allocation(hdmi, hparms->cea.channel_allocation);
 
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index bd65d0479683..d1daa369c8ae 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -582,6 +582,76 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk)
 	return n;
 }
 
+/*
+ * When transmitting IEC60958 linear PCM audio, these registers allow to
+ * configure the channel status information of all the channel status
+ * bits in the IEC60958 frame. For the moment this configuration is only
+ * used when the I2S audio interface, General Purpose Audio (GPA),
+ * or AHB audio DMA (AHBAUDDMA) interface is active
+ * (for S/PDIF interface this information comes from the stream).
+ */
+void dw_hdmi_set_channel_status(struct dw_hdmi *hdmi,
+				unsigned int sample_width)
+{
+	u8 aud_schnl_samplerate;
+	u8 aud_schnl_8;
+	u8 word_length_bits;
+
+	switch (hdmi->sample_rate) {
+	case 32000:
+		aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_32K;
+		break;
+	case 44100:
+		aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_44K1;
+		break;
+	case 48000:
+		aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_48K;
+		break;
+	case 88200:
+		aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_88K2;
+		break;
+	case 96000:
+		aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_96K;
+		break;
+	case 176400:
+		aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_176K4;
+		break;
+	case 192000:
+		aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_192K;
+		break;
+	case 768000:
+		aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_768K;
+		break;
+	default:
+		dev_warn(hdmi->dev, "Unsupported audio sample rate (%u)\n",
+			 hdmi->sample_rate);
+		return;
+	}
+
+	/* set channel status register */
+	hdmi_modb(hdmi, aud_schnl_samplerate, HDMI_FC_AUDSCHNLS7_SMPRATE_MASK,
+		  HDMI_FC_AUDSCHNLS7);
+
+	/*
+	 * Set original frequency to be the same as frequency.
+	 * Use one-complement value as stated in IEC60958-3 page 13.
+	 */
+	aud_schnl_8 = (~aud_schnl_samplerate) <<
+			HDMI_FC_AUDSCHNLS8_ORIGSAMPFREQ_OFFSET;
+
+	/*
+	 * Refer to IEC60958-3 page 12. We can accept 16 bits or 24 bits.
+	 * Otherwise, set the register to 0t o indicate using default value.
+	 */
+	word_length_bits = (sample_width == 16) ? 0x2 :
+			    ((sample_width == 24) ? 0xb : 0);
+
+	aud_schnl_8 |= word_length_bits << HDMI_FC_AUDSCHNLS8_WORDLEGNTH_OFFSET;
+
+	hdmi_writeb(hdmi, aud_schnl_8, HDMI_FC_AUDSCHNLS8);
+}
+EXPORT_SYMBOL_GPL(dw_hdmi_set_channel_status);
+
 static void hdmi_set_clk_regenerator(struct dw_hdmi *hdmi,
 	unsigned long pixel_clk, unsigned int sample_rate)
 {
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
index 6988f12d89d9..619ebc1c8354 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
@@ -158,6 +158,17 @@
 #define HDMI_FC_SPDDEVICEINF                    0x1062
 #define HDMI_FC_AUDSCONF                        0x1063
 #define HDMI_FC_AUDSSTAT                        0x1064
+#define HDMI_FC_AUDSV                           0x1065
+#define HDMI_FC_AUDSU                           0x1066
+#define HDMI_FC_AUDSCHNLS0                      0x1067
+#define HDMI_FC_AUDSCHNLS1                      0x1068
+#define HDMI_FC_AUDSCHNLS2                      0x1069
+#define HDMI_FC_AUDSCHNLS3                      0x106a
+#define HDMI_FC_AUDSCHNLS4                      0x106b
+#define HDMI_FC_AUDSCHNLS5                      0x106c
+#define HDMI_FC_AUDSCHNLS6                      0x106d
+#define HDMI_FC_AUDSCHNLS7                      0x106e
+#define HDMI_FC_AUDSCHNLS8                      0x106f
 #define HDMI_FC_DATACH0FILL                     0x1070
 #define HDMI_FC_DATACH1FILL                     0x1071
 #define HDMI_FC_DATACH2FILL                     0x1072
@@ -706,6 +717,15 @@ enum {
 /* HDMI_FC_AUDSCHNLS7 field values */
 	HDMI_FC_AUDSCHNLS7_ACCURACY_OFFSET = 4,
 	HDMI_FC_AUDSCHNLS7_ACCURACY_MASK = 0x30,
+	HDMI_FC_AUDSCHNLS7_SMPRATE_MASK = 0x0f,
+	HDMI_FC_AUDSCHNLS7_SMPRATE_192K = 0xe,
+	HDMI_FC_AUDSCHNLS7_SMPRATE_176K4 = 0xc,
+	HDMI_FC_AUDSCHNLS7_SMPRATE_96K = 0xa,
+	HDMI_FC_AUDSCHNLS7_SMPRATE_768K = 0x9,
+	HDMI_FC_AUDSCHNLS7_SMPRATE_88K2 = 0x8,
+	HDMI_FC_AUDSCHNLS7_SMPRATE_32K = 0x3,
+	HDMI_FC_AUDSCHNLS7_SMPRATE_48K = 0x2,
+	HDMI_FC_AUDSCHNLS7_SMPRATE_44K1 = 0x0,
 
 /* HDMI_FC_AUDSCHNLS8 field values */
 	HDMI_FC_AUDSCHNLS8_ORIGSAMPFREQ_MASK = 0xf0,
diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index cf528c289857..12144d2f80f4 100644
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -156,6 +156,8 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense);
 
 void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate);
 void dw_hdmi_set_channel_count(struct dw_hdmi *hdmi, unsigned int cnt);
+void dw_hdmi_set_channel_status(struct dw_hdmi *hdmi,
+				unsigned int sample_width);
 void dw_hdmi_set_channel_allocation(struct dw_hdmi *hdmi, unsigned int ca);
 void dw_hdmi_audio_enable(struct dw_hdmi *hdmi);
 void dw_hdmi_audio_disable(struct dw_hdmi *hdmi);
-- 
2.23.0.187.g17f5b7556c-goog