[alsa-devel] [PATCH] drm: exynos: Add driver for HDMI audio interface

Sylwester Nawrocki s.nawrocki at samsung.com
Thu Aug 3 11:22:33 CEST 2017


The hdmi-codec interface added in this patch is required to properly
support HDMI audio. Currently the audio part of the SoC internal
HDMI transmitter is configured with fixed values, which makes HDMI
audio working by chance, only on boards equipped with external audio
codec connected in parallel with the HDMI audio transmitter I2S input
interface.

Signed-off-by: Sylwester Nawrocki <s.nawrocki at samsung.com>
---
Changes since RFC version:
 - fixed hdmi-codec locking issue
 - added a comment documenting struct hdmi_contex::mutex
---
 drivers/gpu/drm/exynos/Kconfig       |   1 +
 drivers/gpu/drm/exynos/exynos_hdmi.c | 226 +++++++++++++++++++++++++++++------
 2 files changed, 193 insertions(+), 34 deletions(-)

diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
index 1d18534..a6edbb6 100644
--- a/drivers/gpu/drm/exynos/Kconfig
+++ b/drivers/gpu/drm/exynos/Kconfig
@@ -3,6 +3,7 @@ config DRM_EXYNOS
 	depends on OF && DRM && (ARCH_S3C64XX || ARCH_EXYNOS || ARCH_MULTIPLATFORM)
 	select DRM_KMS_HELPER
 	select VIDEOMODE_HELPERS
+	select SND_SOC_HDMI_CODEC if SND_SOC
 	help
 	  Choose this option if you have a Samsung SoC EXYNOS chipset.
 	  If M is selected the module will be called exynosdrm.
diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index 06bfbe4..64eadf58 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -40,7 +40,7 @@
 #include <linux/component.h>
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
-
+#include <sound/hdmi-codec.h>
 #include <drm/exynos_drm.h>
 
 #include <media/cec-notifier.h>
@@ -111,12 +111,19 @@ struct hdmi_driver_data {
 	struct string_array_spec clk_muxes;
 };
 
+struct hdmi_audio {
+	struct platform_device *pdev;
+	struct hdmi_audio_infoframe infoframe;
+	unsigned int sample_rate;
+	unsigned int sample_width;
+	u8 enable;
+};
+
 struct hdmi_context {
 	struct drm_encoder		encoder;
 	struct device			*dev;
 	struct drm_device		*drm_dev;
 	struct drm_connector		connector;
-	bool				powered;
 	bool				dvi_mode;
 	struct delayed_work		hotplug_work;
 	struct drm_display_mode		current_mode;
@@ -137,6 +144,11 @@ struct hdmi_context {
 	struct regulator		*reg_hdmi_en;
 	struct exynos_drm_clk		phy_clk;
 	struct drm_bridge		*bridge;
+
+	/* mutex protecting subsequent fields below */
+	struct mutex			mutex;
+	struct hdmi_audio		audio;
+	bool				powered;
 };
 
 static inline struct hdmi_context *encoder_to_hdmi(struct drm_encoder *e)
@@ -768,6 +780,22 @@ static int hdmi_clk_set_parents(struct hdmi_context *hdata, bool to_phy)
 	return ret;
 }
 
+static int hdmi_audio_infoframe_apply(struct hdmi_context *hdata)
+{
+	struct hdmi_audio_infoframe *infoframe = &hdata->audio.infoframe;
+	u8 buf[HDMI_INFOFRAME_SIZE(AUDIO)];
+	int len;
+
+	len = hdmi_audio_infoframe_pack(infoframe, buf, sizeof(buf));
+	if (len < 0)
+		return len;
+
+	hdmi_reg_writeb(hdata, HDMI_AUI_CON, HDMI_AUI_CON_EVERY_VSYNC);
+	hdmi_reg_write_buf(hdata, HDMI_AUI_HEADER0, buf, len);
+
+	return 0;
+}
+
 static void hdmi_reg_infoframes(struct hdmi_context *hdata)
 {
 	union hdmi_infoframe frm;
@@ -805,15 +833,7 @@ static void hdmi_reg_infoframes(struct hdmi_context *hdata)
 		hdmi_reg_write_buf(hdata, HDMI_VSI_DATA(0), buf + 3, ret - 3);
 	}
 
-	ret = hdmi_audio_infoframe_init(&frm.audio);
-	if (!ret) {
-		frm.audio.channels = 2;
-		ret = hdmi_audio_infoframe_pack(&frm.audio, buf, sizeof(buf));
-	}
-	if (ret > 0) {
-		hdmi_reg_writeb(hdata, HDMI_AUI_CON, HDMI_AUI_CON_EVERY_VSYNC);
-		hdmi_reg_write_buf(hdata, HDMI_AUI_HEADER0, buf, ret);
-	}
+	hdmi_audio_infoframe_apply(hdata);
 }
 
 static enum drm_connector_status hdmi_detect(struct drm_connector *connector,
@@ -996,23 +1016,18 @@ static void hdmi_reg_acr(struct hdmi_context *hdata, u32 freq)
 	hdmi_reg_writeb(hdata, HDMI_ACR_CON, 4);
 }
 
-static void hdmi_audio_init(struct hdmi_context *hdata)
+static void hdmi_audio_config(struct hdmi_context *hdata)
 {
-	u32 sample_rate, bits_per_sample;
-	u32 data_num, bit_ch, sample_frq;
-	u32 val;
+	u32 data_num, sample_freq, val;
+	u32 bit_ch = 1;
 
-	sample_rate = 44100;
-	bits_per_sample = 16;
 
-	switch (bits_per_sample) {
+	switch (hdata->audio.sample_width) {
 	case 20:
 		data_num = 2;
-		bit_ch = 1;
 		break;
 	case 24:
 		data_num = 3;
-		bit_ch = 1;
 		break;
 	default:
 		data_num = 1;
@@ -1020,7 +1035,7 @@ static void hdmi_audio_init(struct hdmi_context *hdata)
 		break;
 	}
 
-	hdmi_reg_acr(hdata, sample_rate);
+	hdmi_reg_acr(hdata, hdata->audio.sample_rate);
 
 	hdmi_reg_writeb(hdata, HDMI_I2S_MUX_CON, HDMI_I2S_IN_DISABLE
 				| HDMI_I2S_AUD_I2S | HDMI_I2S_CUV_I2S_ENABLE
@@ -1031,10 +1046,21 @@ static void hdmi_audio_init(struct hdmi_context *hdata)
 
 	hdmi_reg_writeb(hdata, HDMI_I2S_MUX_CUV, HDMI_I2S_CUV_RL_EN);
 
-	sample_frq = (sample_rate == 44100) ? 0 :
-			(sample_rate == 48000) ? 2 :
-			(sample_rate == 32000) ? 3 :
-			(sample_rate == 96000) ? 0xa : 0x0;
+	switch(hdata->audio.sample_rate) {
+	case 32000:
+		sample_freq = 0x3;
+		break;
+	case 48000:
+		sample_freq = 0x2;
+		break;
+	case 96000:
+		sample_freq = 0xa;
+		break;
+	case 44100:
+	default:
+		sample_freq = 0;
+		break;
+	}
 
 	hdmi_reg_writeb(hdata, HDMI_I2S_CLK_CON, HDMI_I2S_CLK_DIS);
 	hdmi_reg_writeb(hdata, HDMI_I2S_CLK_CON, HDMI_I2S_CLK_EN);
@@ -1068,7 +1094,7 @@ static void hdmi_audio_init(struct hdmi_context *hdata)
 	hdmi_reg_writeb(hdata, HDMI_I2S_CH_ST_1, HDMI_I2S_CD_PLAYER);
 	hdmi_reg_writeb(hdata, HDMI_I2S_CH_ST_2, HDMI_I2S_SET_SOURCE_NUM(0));
 	hdmi_reg_writeb(hdata, HDMI_I2S_CH_ST_3, HDMI_I2S_CLK_ACCUR_LEVEL_2
-			| HDMI_I2S_SET_SMP_FREQ(sample_frq));
+			| HDMI_I2S_SET_SMP_FREQ(sample_freq));
 	hdmi_reg_writeb(hdata, HDMI_I2S_CH_ST_4,
 			HDMI_I2S_ORG_SMP_FREQ_44_1
 			| HDMI_I2S_WORD_LEN_MAX24_24BITS
@@ -1077,13 +1103,15 @@ static void hdmi_audio_init(struct hdmi_context *hdata)
 	hdmi_reg_writeb(hdata, HDMI_I2S_CH_ST_CON, HDMI_I2S_CH_STATUS_RELOAD);
 }
 
-static void hdmi_audio_control(struct hdmi_context *hdata, bool onoff)
+static void hdmi_audio_control(struct hdmi_context *hdata)
 {
+	bool enable = hdata->audio.enable;
+
 	if (hdata->dvi_mode)
 		return;
 
-	hdmi_reg_writeb(hdata, HDMI_AUI_CON, onoff ? 2 : 0);
-	hdmi_reg_writemask(hdata, HDMI_CON_0, onoff ?
+	hdmi_reg_writeb(hdata, HDMI_AUI_CON, enable ? 2 : 0);
+	hdmi_reg_writemask(hdata, HDMI_CON_0, enable ?
 			HDMI_ASP_EN : HDMI_ASP_DIS, HDMI_ASP_MASK);
 }
 
@@ -1403,9 +1431,9 @@ static void hdmi_conf_apply(struct hdmi_context *hdata)
 {
 	hdmi_start(hdata, false);
 	hdmi_conf_init(hdata);
-	hdmi_audio_init(hdata);
+	hdmi_audio_config(hdata);
 	hdmi_mode_apply(hdata);
-	hdmi_audio_control(hdata, true);
+	hdmi_audio_control(hdata);
 }
 
 static void hdmi_mode_set(struct drm_encoder *encoder,
@@ -1479,17 +1507,24 @@ static void hdmi_enable(struct drm_encoder *encoder)
 {
 	struct hdmi_context *hdata = encoder_to_hdmi(encoder);
 
+	mutex_lock(&hdata->mutex);
+
 	hdmiphy_enable(hdata);
 	hdmi_conf_apply(hdata);
+
+	mutex_unlock(&hdata->mutex);
 }
 
 static void hdmi_disable(struct drm_encoder *encoder)
 {
 	struct hdmi_context *hdata = encoder_to_hdmi(encoder);
 
-	if (!hdata->powered)
-		return;
+	mutex_lock(&hdata->mutex);
 
+	if (!hdata->powered) {
+		mutex_unlock(&hdata->mutex);
+		return;
+	}
 	/*
 	 * The SFRs of VP and Mixer are updated by Vertical Sync of
 	 * Timing generator which is a part of HDMI so the sequence
@@ -1503,6 +1538,8 @@ static void hdmi_disable(struct drm_encoder *encoder)
 	cec_notifier_set_phys_addr(hdata->notifier, CEC_PHYS_ADDR_INVALID);
 
 	hdmiphy_disable(hdata);
+
+	mutex_unlock(&hdata->mutex);
 }
 
 static const struct drm_encoder_helper_funcs exynos_hdmi_encoder_helper_funcs = {
@@ -1516,6 +1553,109 @@ static void hdmi_disable(struct drm_encoder *encoder)
 	.destroy = drm_encoder_cleanup,
 };
 
+static void hdmi_audio_shutdown(struct device *dev, void *data)
+{
+	struct hdmi_context *hdata = dev_get_drvdata(dev);
+
+	mutex_lock(&hdata->mutex);
+
+	hdata->audio.enable = false;
+
+	if (hdata->powered)
+		hdmi_audio_control(hdata);
+
+	mutex_unlock(&hdata->mutex);
+}
+
+static int hdmi_audio_hw_params(struct device *dev, void *data,
+				struct hdmi_codec_daifmt *daifmt,
+				struct hdmi_codec_params *params)
+{
+	struct hdmi_context *hdata = dev_get_drvdata(dev);
+
+	if (daifmt->fmt != HDMI_I2S || daifmt->bit_clk_inv ||
+	    daifmt->frame_clk_inv || daifmt->bit_clk_master ||
+	    daifmt->frame_clk_master) {
+		dev_err(dev, "%s: Bad flags %d %d %d %d\n", __func__,
+			daifmt->bit_clk_inv, daifmt->frame_clk_inv,
+			daifmt->bit_clk_master,
+			daifmt->frame_clk_master);
+		return -EINVAL;
+	}
+
+	mutex_lock(&hdata->mutex);
+
+	hdata->audio.sample_rate = params->sample_rate;
+	hdata->audio.sample_width = params->sample_width;
+	hdata->audio.infoframe = params->cea;
+
+	if (hdata->powered) {
+		hdmi_audio_config(hdata);
+		hdmi_audio_infoframe_apply(hdata);
+	}
+
+	mutex_unlock(&hdata->mutex);
+
+	return 0;
+}
+
+static int hdmi_audio_digital_mute(struct device *dev, void *data, bool mute)
+{
+	struct hdmi_context *hdata = dev_get_drvdata(dev);
+
+	mutex_lock(&hdata->mutex);
+
+	hdata->audio.enable = !mute;
+
+	if (hdata->powered)
+		hdmi_audio_control(hdata);
+
+	mutex_unlock(&hdata->mutex);
+
+	return 0;
+}
+
+static int hdmi_audio_get_eld(struct device *dev, void *data, uint8_t *buf,
+			      size_t len)
+{
+	struct hdmi_context *hdata = dev_get_drvdata(dev);
+	struct drm_connector *connector = &hdata->connector;
+
+	memcpy(buf, connector->eld, min(sizeof(connector->eld), len));
+
+	return 0;
+}
+
+static const struct hdmi_codec_ops audio_codec_ops = {
+	.hw_params = hdmi_audio_hw_params,
+	.audio_shutdown = hdmi_audio_shutdown,
+	.digital_mute = hdmi_audio_digital_mute,
+	.get_eld = hdmi_audio_get_eld,
+};
+
+static int hdmi_register_audio_device(struct hdmi_context *hdata)
+{
+	struct hdmi_codec_pdata codec_data = {
+		.ops = &audio_codec_ops,
+		.max_i2s_channels = 6,
+		.i2s = 1,
+	};
+
+	hdata->audio.pdev = platform_device_register_data(
+		hdata->dev, HDMI_CODEC_DRV_NAME, PLATFORM_DEVID_AUTO,
+		&codec_data, sizeof(codec_data));
+
+	if (IS_ERR(hdata->audio.pdev))
+		return PTR_ERR(hdata->audio.pdev);
+
+	return 0;
+}
+
+static void hdmi_unregister_audio_device(struct hdmi_context *hdata)
+{
+	platform_device_unregister(hdata->audio.pdev);
+}
+
 static void hdmi_hotplug_work_func(struct work_struct *work)
 {
 	struct hdmi_context *hdata;
@@ -1700,6 +1840,7 @@ static int hdmi_bind(struct device *dev, struct device *master, void *data)
 	struct drm_device *drm_dev = data;
 	struct hdmi_context *hdata = dev_get_drvdata(dev);
 	struct drm_encoder *encoder = &hdata->encoder;
+	struct hdmi_audio_infoframe *audio_infoframe = &hdata->audio.infoframe;
 	struct exynos_drm_crtc *exynos_crtc;
 	struct drm_crtc *crtc;
 	int ret, pipe;
@@ -1721,6 +1862,12 @@ static int hdmi_bind(struct device *dev, struct device *master, void *data)
 
 	DRM_DEBUG_KMS("possible_crtcs = 0x%x\n", encoder->possible_crtcs);
 
+	hdmi_audio_infoframe_init(audio_infoframe);
+	audio_infoframe->coding_type = HDMI_AUDIO_CODING_TYPE_STREAM;
+	audio_infoframe->sample_size = HDMI_AUDIO_SAMPLE_SIZE_STREAM;
+	audio_infoframe->sample_frequency = HDMI_AUDIO_SAMPLE_FREQUENCY_STREAM;
+	audio_infoframe->channels = 2;
+
 	drm_encoder_init(drm_dev, encoder, &exynos_hdmi_encoder_funcs,
 			 DRM_MODE_ENCODER_TMDS, NULL);
 
@@ -1828,6 +1975,8 @@ static int hdmi_probe(struct platform_device *pdev)
 
 	hdata->dev = dev;
 
+	mutex_init(&hdata->mutex);
+
 	ret = hdmi_resources_init(hdata);
 	if (ret) {
 		if (ret != -EPROBE_DEFER)
@@ -1887,12 +2036,19 @@ static int hdmi_probe(struct platform_device *pdev)
 
 	pm_runtime_enable(dev);
 
-	ret = component_add(&pdev->dev, &hdmi_component_ops);
+	ret = hdmi_register_audio_device(hdata);
 	if (ret)
 		goto err_notifier_put;
 
+	ret = component_add(&pdev->dev, &hdmi_component_ops);
+	if (ret)
+		goto err_unregister_audio;
+
 	return ret;
 
+err_unregister_audio:
+	hdmi_unregister_audio_device(hdata);
+
 err_notifier_put:
 	cec_notifier_put(hdata->notifier);
 	pm_runtime_disable(dev);
@@ -1931,6 +2087,8 @@ static int hdmi_remove(struct platform_device *pdev)
 
 	put_device(&hdata->ddc_adpt->dev);
 
+	mutex_destroy(&hdata->mutex);
+
 	return 0;
 }
 
-- 
1.9.1



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