From: Libin Yang <libin.y...@intel.com>
HDMI audio may not work at some frequencies
with the HW provided N/CTS.
This patch sets the proper N value for the
given audio sample rate at the impacted frequencies.
At other frequencies, it will use the N/CTS value
which HW provides.
Signed-off-by: Libin Yang <libin.y...@intel.com>
---
drivers/gpu/drm/i915/intel_audio.c | 117 +++++++++++++++++++++++++++++++++++++
1 file changed, 117 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_audio.c
b/drivers/gpu/drm/i915/intel_audio.c
index dc32cf4..27add6a 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -68,6 +68,31 @@ static const struct {
{ 148500, AUD_CONFIG_PIXEL_CLOCK_HDMI_148500 },
};
+/* HDMI N/CTS table */
+#define TMDS_297M 297000
+#define TMDS_296M DIV_ROUND_UP(297000 * 1000, 1001)
+static const struct {
+ int sample_rate;
+ int clock;
+ int n;
+ int cts;
+} aud_ncts[] = {
+ { 44100, TMDS_296M, 4459, 234375 },
+ { 44100, TMDS_297M, 4704, 247500 },
+ { 48000, TMDS_296M, 5824, 281250 },
+ { 48000, TMDS_297M, 5120, 247500 },
+ { 32000, TMDS_296M, 5824, 421875 },
+ { 32000, TMDS_297M, 3072, 222750 },
+ { 88200, TMDS_296M, 8918, 234375 },
+ { 88200, TMDS_297M, 9408, 247500 },
+ { 96000, TMDS_296M, 11648, 281250 },
+ { 96000, TMDS_297M, 10240, 247500 },
+ { 176400, TMDS_296M, 17836, 234375 },
+ { 176400, TMDS_297M, 18816, 247500 },
+ { 44100, TMDS_296M, 23296, 281250 },
+ { 44100, TMDS_297M, 20480, 247500 },
+};
+
/* get AUD_CONFIG_PIXEL_CLOCK_HDMI_* value for mode */
static u32 audio_config_hdmi_pixel_clock(struct drm_display_mode *mode)
{
@@ -90,6 +115,31 @@ static u32 audio_config_hdmi_pixel_clock(struct
drm_display_mode *mode)
return hdmi_audio_clock[i].config;
}
+static int audio_config_get_n(struct drm_display_mode *mode, int rate)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(aud_ncts); i++) {
+ if ((rate == aud_ncts[i].sample_rate) &&
+ (mode->clock == aud_ncts[i].clock)) {
+ return aud_ncts[i].n;
+ }
+ }
+ return 0;
+}
+
+/* check whether N/CTS/M need be set manually */
+static bool audio_rate_need_prog(struct intel_crtc *crtc,
+ struct drm_display_mode *mode)
+{
+ if (((mode->clock == TMDS_297M) ||
+ (mode->clock == TMDS_296M)) &&
+ intel_pipe_has_type(crtc, INTEL_OUTPUT_HDMI))
+ return true;
+ else
+ return false;
+}
+
static bool intel_eld_uptodate(struct drm_connector *connector,
int reg_eldv, uint32_t bits_eldv,
int reg_elda, uint32_t bits_elda,
@@ -514,12 +564,79 @@ static int i915_audio_component_get_cdclk_freq(struct
device *dev)
return ret;
}
+static int i915_audio_component_sync_audio_rate(struct device *dev,
+ int port, int rate)
+{
+ struct drm_i915_private *dev_priv = dev_to_i915(dev);
+ struct drm_device *drm_dev = dev_priv->dev;
+ struct intel_encoder *intel_encoder;
+ struct intel_digital_port *intel_dig_port;
+ struct intel_crtc *crtc;
+ struct drm_display_mode *mode;
+ enum pipe pipe = -1;
+ u32 tmp;
+ int n_low, n_up, n;
+
+ /* 1. get the pipe */
+ for_each_intel_encoder(drm_dev, intel_encoder) {
+ intel_dig_port = enc_to_dig_port(&intel_encoder->base);
+ if (port == intel_dig_port->port) {
+ crtc = to_intel_crtc(intel_encoder->base.crtc);
+ if (!crtc) {
+ DRM_DEBUG_KMS("%s: crtc is NULL\n", __func__);
+ continue;
+ }
+ pipe = crtc->pipe;
+ break;
+ }
+ }
+
+ if (pipe == INVALID_PIPE) {
+ DRM_DEBUG_KMS("no pipe for the port %c\n", port_name(port));
+ return -ENODEV;
+ }
+ DRM_DEBUG_KMS("pipe %c connects port %c\n",
+ pipe_name(pipe), port_name(port));
+ mode = &crtc->config->base.adjusted_mode;
+
+ /* 2. check whether to set the N/CTS/M manually or not */
+ if (!audio_rate_need_prog(crtc, mode)) {
+ tmp = I915_READ(HSW_AUD_CFG(pipe));
+ tmp &= ~AUD_CONFIG_N_PROG_ENABLE;
+ I915_WRITE(HSW_AUD_CFG(pipe), tmp);
+ return 0;
+ }
+
+ n = audio_config_get_n(mode, rate);
+ if (n == 0) {
+ DRM_DEBUG_KMS("Using automatic mode for N value on port %c\n",
+ port_name(port));
+ tmp = I915_READ(HSW_AUD_CFG(pipe));
+ tmp &= ~AUD_CONFIG_N_PROG_ENABLE;
+ I915_WRITE(HSW_AUD_CFG(pipe), tmp);
+ return 0;
+ }
+ n_low = n & 0xfff;
+ n_up = (n >> 12) & 0xff;
+
+ /* 4. set the N/CTS/M */
+ tmp = I915_READ(HSW_AUD_CFG(pipe));
+ tmp &= ~(AUD_CONFIG_UPPER_N_MASK | AUD_CONFIG_LOWER_N_MASK);
+ tmp |= ((n_up << AUD_CONFIG_UPPER_N_SHIFT) |
+ (n_low << AUD_CONFIG_LOWER_N_SHIFT) |
+ AUD_CONFIG_N_PROG_ENABLE);
+ I915_WRITE(HSW_AUD_CFG(pipe), tmp);
+
+ return 0;
+}
+
static const struct i915_audio_component_ops i915_audio_component_ops = {
.owner = THIS_MODULE,
.get_power = i915_audio_component_get_power,
.put_power = i915_audio_component_put_power,
.codec_wake_override = i915_audio_component_codec_wake_override,
.get_cdclk_freq = i915_audio_component_get_cdclk_freq,
+ .sync_audio_rate = i915_audio_component_sync_audio_rate,
};
static int i915_audio_component_bind(struct device *i915_dev,
--
1.9.1
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