[PATCH v7 9/9] drm/mediatek: hdmi: use helper function for N and CTS calculation
Philipp Zabel
p.zabel at pengutronix.de
Wed Apr 20 02:00:04 PDT 2016
Use the hdmi helper function [1] to calculate N and CTS.
[1] https://patchwork.kernel.org/patch/8091531/ ("video: hdmi: add helper
function for N and CTS")
Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
---
drivers/gpu/drm/mediatek/mtk_hdmi.c | 85 +++++++++----------------------------
1 file changed, 21 insertions(+), 64 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index 06e3811..da6edef 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
@@ -656,65 +656,6 @@ static const struct hdmi_acr_n hdmi_rec_n_table[] = {
{ 0, { 4096, 6272, 6144 } }, /* all other TMDS clocks */
};
-/**
- * hdmi_recommended_n() - Return N value recommended by HDMI specification
- * @freq: audio sample rate in Hz
- * @clock: rounded TMDS clock in kHz
- */
-static unsigned int hdmi_recommended_n(unsigned int freq, unsigned int clock)
-{
- const struct hdmi_acr_n *recommended;
- unsigned int i;
-
- for (i = 0; i < ARRAY_SIZE(hdmi_rec_n_table) - 1; i++) {
- if (clock == hdmi_rec_n_table[i].clock)
- break;
- }
- recommended = hdmi_rec_n_table + i;
-
- switch (freq) {
- case 32000:
- return recommended->n[0];
- case 44100:
- return recommended->n[1];
- case 48000:
- return recommended->n[2];
- case 88200:
- return recommended->n[1] * 2;
- case 96000:
- return recommended->n[2] * 2;
- case 176400:
- return recommended->n[1] * 4;
- case 192000:
- return recommended->n[2] * 4;
- default:
- return (128 * freq) / 1000;
- }
-}
-
-static unsigned int hdmi_mode_clock_to_hz(unsigned int clock)
-{
- switch (clock) {
- case 25175:
- return 25174825; /* 25.2/1.001 MHz */
- case 74176:
- return 74175824; /* 74.25/1.001 MHz */
- case 148352:
- return 148351648; /* 148.5/1.001 MHz */
- case 296703:
- return 296703297; /* 297/1.001 MHz */
- default:
- return clock * 1000;
- }
-}
-
-static unsigned int hdmi_expected_cts(unsigned int audio_sample_rate,
- unsigned int tmds_clock, unsigned int n)
-{
- return DIV_ROUND_CLOSEST_ULL((u64)hdmi_mode_clock_to_hz(tmds_clock) * n,
- 128 * audio_sample_rate);
-}
-
static void do_hdmi_hw_aud_set_ncts(struct mtk_hdmi *hdmi, unsigned int n,
unsigned int cts)
{
@@ -739,21 +680,37 @@ static void do_hdmi_hw_aud_set_ncts(struct mtk_hdmi *hdmi, unsigned int n,
mtk_hdmi_write(hdmi, GRL_NCTS, val[i]);
}
+static unsigned int hdmi_mode_clock_to_hz(unsigned int clock)
+{
+ switch (clock) {
+ case 25175:
+ return 25174825; /* 25.2/1.001 MHz */
+ case 74176:
+ return 74175824; /* 74.25/1.001 MHz */
+ case 148352:
+ return 148351648; /* 148.5/1.001 MHz */
+ case 296703:
+ return 296703296; /* 297/1.001 MHz */
+ default:
+ return clock * 1000;
+ }
+}
+
static void mtk_hdmi_hw_aud_set_ncts(struct mtk_hdmi *hdmi,
unsigned int sample_rate,
unsigned int clock)
{
- unsigned int n, cts;
+ struct hdmi_audio_n_cts n_cts;
- n = hdmi_recommended_n(sample_rate, clock);
- cts = hdmi_expected_cts(sample_rate, clock, n);
+ hdmi_audio_get_coherent_n_cts(sample_rate, hdmi_mode_clock_to_hz(clock),
+ &n_cts);
dev_dbg(hdmi->dev, "%s: sample_rate=%u, clock=%d, cts=%u, n=%u\n",
- __func__, sample_rate, clock, n, cts);
+ __func__, sample_rate, clock, n_cts.cts, n_cts.n);
mtk_hdmi_mask(hdmi, DUMMY_304, AUDIO_I2S_NCTS_SEL_64,
AUDIO_I2S_NCTS_SEL);
- do_hdmi_hw_aud_set_ncts(hdmi, n, cts);
+ do_hdmi_hw_aud_set_ncts(hdmi, n_cts.n, n_cts.cts);
}
static u8 mtk_hdmi_aud_get_chnl_count(enum hdmi_aud_channel_type channel_type)
--
2.8.0.rc3
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