Re: [PATCH] drm/tegra: sor: Support for audio over HDMI

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 03 Dec 2018, Thierry Reding <thierry.reding@gmail.com> wrote:
> From: Thierry Reding <treding@nvidia.com>
>
> This code is very similar to the audio over HDMI support on older chips.
> Interoperation with the audio codec is done via a pair of codec scratch
> registers and an interrupt that is raised at the SOR when the codec has
> written those registers.
>
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/gpu/drm/tegra/sor.c | 229 ++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/tegra/sor.h |  68 +++++++++++
>  2 files changed, 297 insertions(+)
>
> diff --git a/drivers/gpu/drm/tegra/sor.c b/drivers/gpu/drm/tegra/sor.c
> index b129da2e5afd..22a54434a757 100644
> --- a/drivers/gpu/drm/tegra/sor.c
> +++ b/drivers/gpu/drm/tegra/sor.c
> @@ -19,6 +19,8 @@
>  
>  #include <soc/tegra/pmc.h>
>  
> +#include <sound/hda_verbs.h>
> +
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_dp_helper.h>
>  #include <drm/drm_panel.h>
> @@ -407,6 +409,7 @@ struct tegra_sor {
>  	const struct tegra_sor_soc *soc;
>  	void __iomem *regs;
>  	unsigned int index;
> +	unsigned int irq;
>  
>  	struct reset_control *rst;
>  	struct clk *clk_parent;
> @@ -433,6 +436,11 @@ struct tegra_sor {
>  
>  	struct delayed_work scdc;
>  	bool scdc_enabled;
> +
> +	struct {
> +		unsigned int sample_rate;
> +		unsigned int channels;
> +	} audio;
>  };
>  
>  struct tegra_sor_state {
> @@ -2139,6 +2147,144 @@ tegra_sor_hdmi_setup_avi_infoframe(struct tegra_sor *sor,
>  	return 0;
>  }
>  
> +static void tegra_sor_write_eld(struct tegra_sor *sor)
> +{
> +	size_t length = drm_eld_size(sor->output.connector.eld), i;

This caught my eye, can't be right?

BR,
Jani.


> +
> +	for (i = 0; i < length; i++)
> +		tegra_sor_writel(sor, i << 8 | sor->output.connector.eld[i],
> +				 SOR_AUDIO_HDA_ELD_BUFWR);
> +
> +	/*
> +	 * The HDA codec will always report an ELD buffer size of 96 bytes and
> +	 * the HDA codec driver will check that each byte read from the buffer
> +	 * is valid. Therefore every byte must be written, even if no 96 bytes
> +	 * were parsed from EDID.
> +	 */
> +	for (i = length; i < 96; i++)
> +		tegra_sor_writel(sor, i << 8 | 0, SOR_AUDIO_HDA_ELD_BUFWR);
> +}
> +
> +static void tegra_sor_audio_prepare(struct tegra_sor *sor)
> +{
> +	u32 value;
> +
> +	tegra_sor_write_eld(sor);
> +
> +	value = SOR_AUDIO_HDA_PRESENSE_ELDV | SOR_AUDIO_HDA_PRESENSE_PD;
> +	tegra_sor_writel(sor, value, SOR_AUDIO_HDA_PRESENSE);
> +}
> +
> +static void tegra_sor_audio_unprepare(struct tegra_sor *sor)
> +{
> +	tegra_sor_writel(sor, 0, SOR_AUDIO_HDA_PRESENSE);
> +}
> +
> +static int tegra_sor_hdmi_enable_audio_infoframe(struct tegra_sor *sor)
> +{
> +	u8 buffer[HDMI_INFOFRAME_SIZE(AUDIO)];
> +	struct hdmi_audio_infoframe frame;
> +	u32 value;
> +	int err;
> +
> +	err = hdmi_audio_infoframe_init(&frame);
> +	if (err < 0) {
> +		dev_err(sor->dev, "failed to setup audio infoframe: %d\n", err);
> +		return err;
> +	}
> +
> +	frame.channels = sor->audio.channels;
> +
> +	err = hdmi_audio_infoframe_pack(&frame, buffer, sizeof(buffer));
> +	if (err < 0) {
> +		dev_err(sor->dev, "failed to pack audio infoframe: %d\n", err);
> +		return err;
> +	}
> +
> +	tegra_sor_hdmi_write_infopack(sor, buffer, err);
> +
> +	value = tegra_sor_readl(sor, SOR_HDMI_AUDIO_INFOFRAME_CTRL);
> +	value |= INFOFRAME_CTRL_CHECKSUM_ENABLE;
> +	value |= INFOFRAME_CTRL_ENABLE;
> +	tegra_sor_writel(sor, value, SOR_HDMI_AUDIO_INFOFRAME_CTRL);
> +
> +	return 0;
> +}
> +
> +static void tegra_sor_hdmi_audio_enable(struct tegra_sor *sor)
> +{
> +	u32 value;
> +
> +	value = tegra_sor_readl(sor, SOR_AUDIO_CNTRL);
> +
> +	/* select HDA audio input */
> +	value &= ~SOR_AUDIO_CNTRL_SOURCE_SELECT(SOURCE_SELECT_MASK);
> +	value |= SOR_AUDIO_CNTRL_SOURCE_SELECT(SOURCE_SELECT_HDA);
> +
> +	/* inject null samples */
> +	if (sor->audio.channels != 2)
> +		value &= ~SOR_AUDIO_CNTRL_INJECT_NULLSMPL;
> +	else
> +		value |= SOR_AUDIO_CNTRL_INJECT_NULLSMPL;
> +
> +	value |= SOR_AUDIO_CNTRL_AFIFO_FLUSH;
> +
> +	tegra_sor_writel(sor, value, SOR_AUDIO_CNTRL);
> +
> +	/* enable advertising HBR capability */
> +	tegra_sor_writel(sor, SOR_AUDIO_SPARE_HBR_ENABLE, SOR_AUDIO_SPARE);
> +
> +	tegra_sor_writel(sor, 0, SOR_HDMI_ACR_CTRL);
> +
> +	value = SOR_HDMI_SPARE_ACR_PRIORITY_HIGH |
> +		SOR_HDMI_SPARE_CTS_RESET(1) |
> +		SOR_HDMI_SPARE_HW_CTS_ENABLE;
> +	tegra_sor_writel(sor, value, SOR_HDMI_SPARE);
> +
> +	/* enable HW CTS */
> +	value = SOR_HDMI_ACR_SUBPACK_LOW_SB1(0);
> +	tegra_sor_writel(sor, value, SOR_HDMI_ACR_0441_SUBPACK_LOW);
> +
> +	/* allow packet to be sent */
> +	value = SOR_HDMI_ACR_SUBPACK_HIGH_ENABLE;
> +	tegra_sor_writel(sor, value, SOR_HDMI_ACR_0441_SUBPACK_HIGH);
> +
> +	/* reset N counter and enable lookup */
> +	value = SOR_HDMI_AUDIO_N_RESET | SOR_HDMI_AUDIO_N_LOOKUP;
> +	tegra_sor_writel(sor, value, SOR_HDMI_AUDIO_N);
> +
> +	value = (24000 * 4096) / (128 * sor->audio.sample_rate / 1000);
> +	tegra_sor_writel(sor, value, SOR_AUDIO_AVAL_0320);
> +	tegra_sor_writel(sor, 4096, SOR_AUDIO_NVAL_0320);
> +
> +	tegra_sor_writel(sor, 20000, SOR_AUDIO_AVAL_0441);
> +	tegra_sor_writel(sor, 4704, SOR_AUDIO_NVAL_0441);
> +
> +	tegra_sor_writel(sor, 20000, SOR_AUDIO_AVAL_0882);
> +	tegra_sor_writel(sor, 9408, SOR_AUDIO_NVAL_0882);
> +
> +	tegra_sor_writel(sor, 20000, SOR_AUDIO_AVAL_1764);
> +	tegra_sor_writel(sor, 18816, SOR_AUDIO_NVAL_1764);
> +
> +	value = (24000 * 6144) / (128 * sor->audio.sample_rate / 1000);
> +	tegra_sor_writel(sor, value, SOR_AUDIO_AVAL_0480);
> +	tegra_sor_writel(sor, 6144, SOR_AUDIO_NVAL_0480);
> +
> +	value = (24000 * 12288) / (128 * sor->audio.sample_rate / 1000);
> +	tegra_sor_writel(sor, value, SOR_AUDIO_AVAL_0960);
> +	tegra_sor_writel(sor, 12288, SOR_AUDIO_NVAL_0960);
> +
> +	value = (24000 * 24576) / (128 * sor->audio.sample_rate / 1000);
> +	tegra_sor_writel(sor, value, SOR_AUDIO_AVAL_1920);
> +	tegra_sor_writel(sor, 24576, SOR_AUDIO_NVAL_1920);
> +
> +	value = tegra_sor_readl(sor, SOR_HDMI_AUDIO_N);
> +	value &= ~SOR_HDMI_AUDIO_N_RESET;
> +	tegra_sor_writel(sor, value, SOR_HDMI_AUDIO_N);
> +
> +	tegra_sor_hdmi_enable_audio_infoframe(sor);
> +}
> +
>  static void tegra_sor_hdmi_disable_audio_infoframe(struct tegra_sor *sor)
>  {
>  	u32 value;
> @@ -2148,6 +2294,11 @@ static void tegra_sor_hdmi_disable_audio_infoframe(struct tegra_sor *sor)
>  	tegra_sor_writel(sor, value, SOR_HDMI_AUDIO_INFOFRAME_CTRL);
>  }
>  
> +static void tegra_sor_hdmi_audio_disable(struct tegra_sor *sor)
> +{
> +	tegra_sor_hdmi_disable_audio_infoframe(sor);
> +}
> +
>  static struct tegra_sor_hdmi_settings *
>  tegra_sor_hdmi_find_settings(struct tegra_sor *sor, unsigned long frequency)
>  {
> @@ -2243,6 +2394,7 @@ static void tegra_sor_hdmi_disable(struct drm_encoder *encoder)
>  	u32 value;
>  	int err;
>  
> +	tegra_sor_audio_unprepare(sor);
>  	tegra_sor_hdmi_scdc_stop(sor);
>  
>  	err = tegra_sor_detach(sor);
> @@ -2651,6 +2803,7 @@ static void tegra_sor_hdmi_enable(struct drm_encoder *encoder)
>  		dev_err(sor->dev, "failed to wakeup SOR: %d\n", err);
>  
>  	tegra_sor_hdmi_scdc_start(sor);
> +	tegra_sor_audio_prepare(sor);
>  }
>  
>  static const struct drm_encoder_helper_funcs tegra_sor_hdmi_helpers = {
> @@ -2666,6 +2819,7 @@ static int tegra_sor_init(struct host1x_client *client)
>  	struct tegra_sor *sor = host1x_client_to_sor(client);
>  	int connector = DRM_MODE_CONNECTOR_Unknown;
>  	int encoder = DRM_MODE_ENCODER_NONE;
> +	u32 value;
>  	int err;
>  
>  	if (!sor->aux) {
> @@ -2759,6 +2913,15 @@ static int tegra_sor_init(struct host1x_client *client)
>  	if (err < 0)
>  		return err;
>  
> +	/*
> +	 * Enable and unmask the HDA codec SCRATCH0 register interrupt. This
> +	 * is used for interoperability between the HDA codec driver and the
> +	 * HDMI/DP driver.
> +	 */
> +	value = SOR_INT_CODEC_SCRATCH1 | SOR_INT_CODEC_SCRATCH0;
> +	tegra_sor_writel(sor, value, SOR_INT_ENABLE);
> +	tegra_sor_writel(sor, value, SOR_INT_MASK);
> +
>  	return 0;
>  }
>  
> @@ -2767,6 +2930,9 @@ static int tegra_sor_exit(struct host1x_client *client)
>  	struct tegra_sor *sor = host1x_client_to_sor(client);
>  	int err;
>  
> +	tegra_sor_writel(sor, 0, SOR_INT_MASK);
> +	tegra_sor_writel(sor, 0, SOR_INT_ENABLE);
> +
>  	tegra_output_exit(&sor->output);
>  
>  	if (sor->aux) {
> @@ -3037,6 +3203,54 @@ static int tegra_sor_parse_dt(struct tegra_sor *sor)
>  	return 0;
>  }
>  
> +static void tegra_hda_parse_format(unsigned int format, unsigned int *rate,
> +				   unsigned int *channels)
> +{
> +	unsigned int mul, div;
> +
> +	if (format & AC_FMT_BASE_44K)
> +		*rate = 44100;
> +	else
> +		*rate = 48000;
> +
> +	mul = (format & AC_FMT_MULT_MASK) >> AC_FMT_MULT_SHIFT;
> +	div = (format & AC_FMT_DIV_MASK) >> AC_FMT_DIV_SHIFT;
> +
> +	*rate = *rate * (mul + 1) / (div + 1);
> +
> +	*channels = (format & AC_FMT_CHAN_MASK) >> AC_FMT_CHAN_SHIFT;
> +}
> +
> +static irqreturn_t tegra_sor_irq(int irq, void *data)
> +{
> +	struct tegra_sor *sor = data;
> +	u32 value;
> +
> +	value = tegra_sor_readl(sor, SOR_INT_STATUS);
> +	tegra_sor_writel(sor, value, SOR_INT_STATUS);
> +
> +	if (value & SOR_INT_CODEC_SCRATCH0) {
> +		value = tegra_sor_readl(sor, SOR_AUDIO_HDA_CODEC_SCRATCH0);
> +
> +		if (value & SOR_AUDIO_HDA_CODEC_SCRATCH0_VALID) {
> +			unsigned int format, sample_rate, channels;
> +
> +			format = value & SOR_AUDIO_HDA_CODEC_SCRATCH0_FMT_MASK;
> +
> +			tegra_hda_parse_format(format, &sample_rate, &channels);
> +
> +			sor->audio.sample_rate = sample_rate;
> +			sor->audio.channels = channels;
> +
> +			tegra_sor_hdmi_audio_enable(sor);
> +		} else {
> +			tegra_sor_hdmi_audio_disable(sor);
> +		}
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
>  static int tegra_sor_probe(struct platform_device *pdev)
>  {
>  	struct device_node *np;
> @@ -3119,6 +3333,21 @@ static int tegra_sor_probe(struct platform_device *pdev)
>  		goto remove;
>  	}
>  
> +	err = platform_get_irq(pdev, 0);
> +	if (err < 0) {
> +		dev_err(&pdev->dev, "failed to get IRQ: %d\n", err);
> +		goto remove;
> +	}
> +
> +	sor->irq = err;
> +
> +	err = devm_request_irq(sor->dev, sor->irq, tegra_sor_irq, 0,
> +			       dev_name(sor->dev), sor);
> +	if (err < 0) {
> +		dev_err(&pdev->dev, "failed to request IRQ: %d\n", err);
> +		goto remove;
> +	}
> +
>  	if (!pdev->dev.pm_domain) {
>  		sor->rst = devm_reset_control_get(&pdev->dev, "sor");
>  		if (IS_ERR(sor->rst)) {
> diff --git a/drivers/gpu/drm/tegra/sor.h b/drivers/gpu/drm/tegra/sor.h
> index fb0854d92a27..13f7e68bec42 100644
> --- a/drivers/gpu/drm/tegra/sor.h
> +++ b/drivers/gpu/drm/tegra/sor.h
> @@ -364,12 +364,28 @@
>  #define  INFOFRAME_HEADER_VERSION(x) (((x) & 0xff) << 8)
>  #define  INFOFRAME_HEADER_TYPE(x) (((x) & 0xff) << 0)
>  
> +#define SOR_HDMI_ACR_CTRL 0xb1
> +
> +#define SOR_HDMI_ACR_0320_SUBPACK_LOW 0xb2
> +#define  SOR_HDMI_ACR_SUBPACK_LOW_SB1(x) (((x) & 0xff) << 24)
> +
> +#define SOR_HDMI_ACR_0320_SUBPACK_HIGH 0xb3
> +#define  SOR_HDMI_ACR_SUBPACK_HIGH_ENABLE (1 << 31)
> +
> +#define SOR_HDMI_ACR_0441_SUBPACK_LOW 0xb4
> +#define SOR_HDMI_ACR_0441_SUBPACK_HIGH 0xb5
> +
>  #define SOR_HDMI_CTRL 0xc0
>  #define  SOR_HDMI_CTRL_ENABLE (1 << 30)
>  #define  SOR_HDMI_CTRL_MAX_AC_PACKET(x) (((x) & 0x1f) << 16)
>  #define  SOR_HDMI_CTRL_AUDIO_LAYOUT (1 << 10)
>  #define  SOR_HDMI_CTRL_REKEY(x) (((x) & 0x7f) << 0)
>  
> +#define SOR_HDMI_SPARE 0xcb
> +#define  SOR_HDMI_SPARE_ACR_PRIORITY_HIGH (1 << 31)
> +#define  SOR_HDMI_SPARE_CTS_RESET(x) (((x) & 0x7) << 16)
> +#define  SOR_HDMI_SPARE_HW_CTS_ENABLE (1 << 0)
> +
>  #define SOR_REFCLK 0xe6
>  #define  SOR_REFCLK_DIV_INT(x) ((((x) >> 2) & 0xff) << 8)
>  #define  SOR_REFCLK_DIV_FRAC(x) (((x) & 0x3) << 6)
> @@ -378,10 +394,62 @@
>  #define  SOR_INPUT_CONTROL_ARM_VIDEO_RANGE_LIMITED (1 << 1)
>  #define  SOR_INPUT_CONTROL_HDMI_SRC_SELECT(x) (((x) & 0x1) << 0)
>  
> +#define SOR_AUDIO_CNTRL 0xfc
> +#define  SOR_AUDIO_CNTRL_INJECT_NULLSMPL (1 << 29)
> +#define  SOR_AUDIO_CNTRL_SOURCE_SELECT(x) (((x) & 0x3) << 20)
> +#define   SOURCE_SELECT_MASK 0x3
> +#define   SOURCE_SELECT_HDA 0x2
> +#define   SOURCE_SELECT_SPDIF 0x1
> +#define   SOURCE_SELECT_AUTO 0x0
> +#define  SOR_AUDIO_CNTRL_AFIFO_FLUSH (1 << 12)
> +
> +#define SOR_AUDIO_SPARE 0xfe
> +#define  SOR_AUDIO_SPARE_HBR_ENABLE (1 << 27)
> +
> +#define SOR_AUDIO_NVAL_0320 0xff
> +#define SOR_AUDIO_NVAL_0441 0x100
> +#define SOR_AUDIO_NVAL_0882 0x101
> +#define SOR_AUDIO_NVAL_1764 0x102
> +#define SOR_AUDIO_NVAL_0480 0x103
> +#define SOR_AUDIO_NVAL_0960 0x104
> +#define SOR_AUDIO_NVAL_1920 0x105
> +
> +#define SOR_AUDIO_HDA_CODEC_SCRATCH0 0x10a
> +#define  SOR_AUDIO_HDA_CODEC_SCRATCH0_VALID (1 << 30)
> +#define  SOR_AUDIO_HDA_CODEC_SCRATCH0_FMT_MASK 0xffff
> +
> +#define SOR_AUDIO_HDA_ELD_BUFWR 0x10c
> +#define  SOR_AUDIO_HDA_ELD_BUFWR_INDEX(x) (((x) & 0xff) << 8)
> +#define  SOR_AUDIO_HDA_ELD_BUFWR_DATA(x) (((x) & 0xff) << 0)
> +
> +#define SOR_AUDIO_HDA_PRESENSE 0x10d
> +#define  SOR_AUDIO_HDA_PRESENSE_ELDV (1 << 1)
> +#define  SOR_AUDIO_HDA_PRESENSE_PD (1 << 0)
> +
> +#define SOR_AUDIO_AVAL_0320 0x10f
> +#define SOR_AUDIO_AVAL_0441 0x110
> +#define SOR_AUDIO_AVAL_0882 0x111
> +#define SOR_AUDIO_AVAL_1764 0x112
> +#define SOR_AUDIO_AVAL_0480 0x113
> +#define SOR_AUDIO_AVAL_0960 0x114
> +#define SOR_AUDIO_AVAL_1920 0x115
> +
> +#define SOR_INT_STATUS 0x11c
> +#define  SOR_INT_CODEC_CP_REQUEST (1 << 2)
> +#define  SOR_INT_CODEC_SCRATCH1 (1 << 1)
> +#define  SOR_INT_CODEC_SCRATCH0 (1 << 0)
> +
> +#define SOR_INT_MASK 0x11d
> +#define SOR_INT_ENABLE 0x11e
> +
>  #define SOR_HDMI_VSI_INFOFRAME_CTRL 0x123
>  #define SOR_HDMI_VSI_INFOFRAME_STATUS 0x124
>  #define SOR_HDMI_VSI_INFOFRAME_HEADER 0x125
>  
> +#define SOR_HDMI_AUDIO_N 0x13c
> +#define SOR_HDMI_AUDIO_N_LOOKUP (1 << 28)
> +#define SOR_HDMI_AUDIO_N_RESET (1 << 20)
> +
>  #define SOR_HDMI2_CTRL 0x13e
>  #define  SOR_HDMI2_CTRL_CLOCK_MODE_DIV_BY_4 (1 << 1)
>  #define  SOR_HDMI2_CTRL_SCRAMBLE (1 << 0)

-- 
Jani Nikula, Intel Open Source Graphics Center
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