diff options
| -rw-r--r-- | drivers/gpu/drm/i2c/tda998x_drv.c | 94 |
1 files changed, 74 insertions, 20 deletions
diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c index f23aee65846c..9b3e47f408ca 100644 --- a/drivers/gpu/drm/i2c/tda998x_drv.c +++ b/drivers/gpu/drm/i2c/tda998x_drv.c @@ -43,6 +43,7 @@ struct tda998x_audio_port { struct tda998x_audio_settings { struct tda998x_audio_params params; u8 i2s_format; + u8 cts_n; }; struct tda998x_priv { @@ -891,6 +892,58 @@ static u8 tda998x_get_adiv(struct tda998x_priv *priv, unsigned int fs) return adiv; } +/* + * In auto-CTS mode, the TDA998x uses a "measured time stamp" counter to + * generate the CTS value. It appears that the "measured time stamp" is + * the number of TDMS clock cycles within a number of audio input clock + * cycles defined by the k and N parameters defined below, in a similar + * way to that which is set out in the CTS generation in the HDMI spec. + * + * tmdsclk ----> mts -> /m ---> CTS + * ^ + * sclk -> /k -> /N + * + * CTS = mts / m, where m is 2^M. + * /k is a divider based on the K value below, K+1 for K < 4, or 8 for K >= 4 + * /N is a divider based on the HDMI specified N value. + * + * This produces the following equation: + * CTS = tmds_clock * k * N / (sclk * m) + * + * When combined with the sink-side equation, and realising that sclk is + * bclk_ratio * fs, we end up with: + * k = m * bclk_ratio / 128. + * + * Note: S/PDIF always uses a bclk_ratio of 64. + */ +static int tda998x_derive_cts_n(struct tda998x_priv *priv, + struct tda998x_audio_settings *settings, + unsigned int ratio) +{ + switch (ratio) { + case 16: + settings->cts_n = CTS_N_M(3) | CTS_N_K(0); + break; + case 32: + settings->cts_n = CTS_N_M(3) | CTS_N_K(1); + break; + case 48: + settings->cts_n = CTS_N_M(3) | CTS_N_K(2); + break; + case 64: + settings->cts_n = CTS_N_M(3) | CTS_N_K(3); + break; + case 128: + settings->cts_n = CTS_N_M(0) | CTS_N_K(0); + break; + default: + dev_err(&priv->hdmi->dev, "unsupported bclk ratio %ufs\n", + ratio); + return -EINVAL; + } + return 0; +} + static void tda998x_audio_mute(struct tda998x_priv *priv, bool on) { if (on) { @@ -905,7 +958,7 @@ static void tda998x_audio_mute(struct tda998x_priv *priv, bool on) static int tda998x_configure_audio(struct tda998x_priv *priv, const struct tda998x_audio_settings *settings) { - u8 buf[6], clksel_aip, clksel_fs, cts_n, adiv; + u8 buf[6], clksel_aip, clksel_fs, adiv; u32 n; adiv = tda998x_get_adiv(priv, settings->params.sample_rate); @@ -920,7 +973,6 @@ static int tda998x_configure_audio(struct tda998x_priv *priv, reg_write(priv, REG_MUX_AP, MUX_AP_SELECT_SPDIF); clksel_aip = AIP_CLKSEL_AIP_SPDIF; clksel_fs = AIP_CLKSEL_FS_FS64SPDIF; - cts_n = CTS_N_M(3) | CTS_N_K(3); break; case AFMT_I2S: @@ -928,20 +980,6 @@ static int tda998x_configure_audio(struct tda998x_priv *priv, reg_write(priv, REG_MUX_AP, MUX_AP_SELECT_I2S); clksel_aip = AIP_CLKSEL_AIP_I2S; clksel_fs = AIP_CLKSEL_FS_ACLK; - switch (settings->params.sample_width) { - case 16: - cts_n = CTS_N_M(3) | CTS_N_K(1); - break; - case 18: - case 20: - case 24: - cts_n = CTS_N_M(3) | CTS_N_K(2); - break; - default: - case 32: - cts_n = CTS_N_M(3) | CTS_N_K(3); - break; - } break; default: @@ -953,7 +991,7 @@ static int tda998x_configure_audio(struct tda998x_priv *priv, reg_write(priv, REG_AIP_CLKSEL, clksel_aip); reg_clear(priv, REG_AIP_CNTRL_0, AIP_CNTRL_0_LAYOUT | AIP_CNTRL_0_ACR_MAN); /* auto CTS */ - reg_write(priv, REG_CTS_N, cts_n); + reg_write(priv, REG_CTS_N, settings->cts_n); reg_write(priv, REG_AUDIO_DIV, adiv); /* @@ -1000,6 +1038,7 @@ static int tda998x_audio_hw_params(struct device *dev, void *data, struct hdmi_codec_params *params) { struct tda998x_priv *priv = dev_get_drvdata(dev); + unsigned int bclk_ratio; bool spdif = daifmt->fmt == HDMI_SPDIF; int i, ret; struct tda998x_audio_settings audio = { @@ -1052,6 +1091,11 @@ static int tda998x_audio_hw_params(struct device *dev, void *data, return -EINVAL; } + bclk_ratio = spdif ? 64 : params->sample_width * 2; + ret = tda998x_derive_cts_n(priv, &audio, bclk_ratio); + if (ret < 0) + return ret; + mutex_lock(&priv->audio_mutex); if (priv->supports_infoframes && priv->sink_has_audio) ret = tda998x_configure_audio(priv, &audio); @@ -1640,8 +1684,8 @@ static int tda998x_get_audio_ports(struct tda998x_priv *priv, return 0; } -static void tda998x_set_config(struct tda998x_priv *priv, - const struct tda998x_encoder_params *p) +static int tda998x_set_config(struct tda998x_priv *priv, + const struct tda998x_encoder_params *p) { priv->vip_cntrl_0 = VIP_CNTRL_0_SWAP_A(p->swap_a) | (p->mirr_a ? VIP_CNTRL_0_MIRR_A : 0) | @@ -1657,9 +1701,17 @@ static void tda998x_set_config(struct tda998x_priv *priv, (p->mirr_f ? VIP_CNTRL_2_MIRR_F : 0); if (p->audio_params.format != AFMT_UNUSED) { + unsigned int ratio; + bool spdif = p->audio_params.format == AFMT_SPDIF; + priv->audio.params = p->audio_params; priv->audio.i2s_format = I2S_FORMAT_PHILIPS; + + ratio = spdif ? 64 : p->audio_params.sample_width * 2; + return tda998x_derive_cts_n(priv, &priv->audio, ratio); } + + return 0; } static void tda998x_destroy(struct device *dev) @@ -1861,7 +1913,9 @@ static int tda998x_create(struct device *dev) if (priv->audio_port[0].format != AFMT_UNUSED) tda998x_audio_codec_init(priv, &client->dev); } else if (dev->platform_data) { - tda998x_set_config(priv, dev->platform_data); + ret = tda998x_set_config(priv, dev->platform_data); + if (ret) + goto fail; } priv->bridge.funcs = &tda998x_bridge_funcs; |