> -----Original Message-----
> From: Kai Vehmanen <kai.vehma...@linux.intel.com>
> Sent: Monday, September 13, 2021 10:10 PM
> To: intel-gfx@lists.freedesktop.org
> Cc: Shankar, Uma <uma.shan...@intel.com>; ville.syrj...@linux.intel.com;
> Nikula,
> Jani <jani.nik...@intel.com>; Kai Vehmanen <kai.vehma...@linux.intel.com>
> Subject: [PATCH v2] drm/i915/display: program audio CDCLK-TS for keepalives
>
> XE_LPD display adds support for display audio codec keepalive feature.
> This feature works also when display codec is in D3 state and the audio link
> is off
> (BCLK off). To enable this functionality, display driver must update the
> AUD_TS_CDCLK_M/N registers whenever CDCLK is changed.
> Actual timestamps are generated only when the audio codec driver specifically
> enables the KeepAlive (KAE) feature.
>
> This patch adds new hooks to intel_set_cdclk() in order to inform display
> audio driver
> when CDCLK change is started and when it is complete.
Looks Good to me.
Reviewed-by: Uma Shankar <uma.shan...@intel.com>
> Bspec: 53679
> Signed-off-by: Kai Vehmanen <kai.vehma...@linux.intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_audio.c | 37 ++++++++++++++++++++++
> drivers/gpu/drm/i915/display/intel_audio.h | 2 ++
> drivers/gpu/drm/i915/display/intel_cdclk.c | 5 +++
> drivers/gpu/drm/i915/i915_reg.h | 4 +++
> 4 files changed, 48 insertions(+)
>
> Changes V1->V2:
> - addressed review comments Jani Nikula (Sep 10)
> - added an initial call to intel_audio_cdclk_change_post() so
> that AUD_CDCLK initial configuration is always performance
>
> diff --git a/drivers/gpu/drm/i915/display/intel_audio.c
> b/drivers/gpu/drm/i915/display/intel_audio.c
> index 532237588511..ff74dc4dc121 100644
> --- a/drivers/gpu/drm/i915/display/intel_audio.c
> +++ b/drivers/gpu/drm/i915/display/intel_audio.c
> @@ -936,6 +936,40 @@ void intel_init_audio_hooks(struct drm_i915_private
> *dev_priv)
> }
> }
>
> +struct aud_ts_cdclk_m_n {
> + u8 m;
> + u16 n;
> +};
> +
> +void intel_audio_cdclk_change_pre(struct drm_i915_private *i915) {
> + if (DISPLAY_VER(i915) >= 13)
> + intel_de_rmw(i915, AUD_TS_CDCLK_M, AUD_TS_CDCLK_M_EN, 0);
> }
> +
> +static void get_aud_ts_cdclk_m_n(int refclk, int cdclk, struct
> +aud_ts_cdclk_m_n *aud_ts) {
> + if (refclk == 24000)
> + aud_ts->m = 12;
> + else
> + aud_ts->m = 15;
> +
> + aud_ts->n = cdclk * aud_ts->m / 24000; }
> +
> +void intel_audio_cdclk_change_post(struct drm_i915_private *i915) {
> + struct aud_ts_cdclk_m_n aud_ts;
> +
> + if (DISPLAY_VER(i915) >= 13) {
> + get_aud_ts_cdclk_m_n(i915->cdclk.hw.ref, i915->cdclk.hw.cdclk,
> +&aud_ts);
> +
> + intel_de_write(i915, AUD_TS_CDCLK_N, aud_ts.n);
> + intel_de_write(i915, AUD_TS_CDCLK_M, aud_ts.m |
> AUD_TS_CDCLK_M_EN);
> + drm_dbg_kms(&i915->drm, "aud_ts_cdclk set to M=%u, N=%u\n",
> aud_ts.m, aud_ts.n);
> + }
> +}
> +
> static int glk_force_audio_cdclk_commit(struct intel_atomic_state *state,
> struct intel_crtc *crtc,
> bool enable)
> @@ -1318,6 +1352,9 @@ static void i915_audio_component_init(struct
> drm_i915_private *dev_priv)
> dev_priv->audio_freq_cntrl = aud_freq;
> }
>
> + /* init with current cdclk */
> + intel_audio_cdclk_change_post(dev_priv);
> +
> dev_priv->audio_component_registered = true; }
>
> diff --git a/drivers/gpu/drm/i915/display/intel_audio.h
> b/drivers/gpu/drm/i915/display/intel_audio.h
> index a3657c7a7ba2..dcb259dd2da7 100644
> --- a/drivers/gpu/drm/i915/display/intel_audio.h
> +++ b/drivers/gpu/drm/i915/display/intel_audio.h
> @@ -18,6 +18,8 @@ void intel_audio_codec_enable(struct intel_encoder *encoder,
> void intel_audio_codec_disable(struct intel_encoder *encoder,
> const struct intel_crtc_state *old_crtc_state,
> const struct drm_connector_state
> *old_conn_state);
> +void intel_audio_cdclk_change_pre(struct drm_i915_private *dev_priv);
> +void intel_audio_cdclk_change_post(struct drm_i915_private *dev_priv);
> void intel_audio_init(struct drm_i915_private *dev_priv); void
> intel_audio_deinit(struct drm_i915_private *dev_priv);
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c
> b/drivers/gpu/drm/i915/display/intel_cdclk.c
> index 9aec17b33819..a1365f31142d 100644
> --- a/drivers/gpu/drm/i915/display/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
> @@ -24,6 +24,7 @@
> #include <linux/time.h>
>
> #include "intel_atomic.h"
> +#include "intel_audio.h"
> #include "intel_bw.h"
> #include "intel_cdclk.h"
> #include "intel_de.h"
> @@ -1943,6 +1944,8 @@ static void intel_set_cdclk(struct drm_i915_private
> *dev_priv,
> intel_psr_pause(intel_dp);
> }
>
> + intel_audio_cdclk_change_pre(dev_priv);
> +
> /*
> * Lock aux/gmbus while we change cdclk in case those
> * functions use cdclk. Not all platforms/ports do, @@ -1971,6 +1974,8
> @@
> static void intel_set_cdclk(struct drm_i915_private *dev_priv,
> intel_psr_resume(intel_dp);
> }
>
> + intel_audio_cdclk_change_post(dev_priv);
> +
> if (drm_WARN(&dev_priv->drm,
> intel_cdclk_changed(&dev_priv->cdclk.hw, cdclk_config),
> "cdclk state doesn't match!\n")) { diff --git
> a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index
> bd63760207b0..795775c9e2eb 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -9734,6 +9734,10 @@ enum {
> #define AUD_PIN_BUF_CTL _MMIO(0x48414)
> #define AUD_PIN_BUF_ENABLE REG_BIT(31)
>
> +#define AUD_TS_CDCLK_M _MMIO(0x65ea0)
> +#define AUD_TS_CDCLK_M_EN REG_BIT(31)
> +#define AUD_TS_CDCLK_N _MMIO(0x65ea4)
> +
> /* Display Audio Config Reg */
> #define AUD_CONFIG_BE _MMIO(0x65ef0)
> #define HBLANK_EARLY_ENABLE_ICL(pipe) (0x1 << (20 - (pipe)))
> --
> 2.32.0
