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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-07-22 10:39:27 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-10-09 17:17:34 +0100 |
| commit | 426701d0ccc13a2819fd99938ec50a888817e77d (patch) | |
| tree | 51ac75c6c6e826cb3ee03de4a203bfe2a7c6f131 /drivers/gpu/drm/bridge | |
| parent | d0c96d168021a60555c692d860334814cc694d8b (diff) | |
| download | lwn-426701d0ccc13a2819fd99938ec50a888817e77d.tar.gz lwn-426701d0ccc13a2819fd99938ec50a888817e77d.zip | |
drm: bridge/dw_hdmi: adjust pixel clock values in N calculation
Adjust the pixel clock values in the N calculation to match the more
accurate clock values we're given by the DRM subsystem, which are the
kHz pixel rate, with any fractional kHz rounded down in the case of
the non-240, non-480 line modes, or rounded up for the others. So,
25.20 / 1.001 => 25175
27.00 * 1.001 => 27027
74.25 / 1.001 => 74176
148.50 / 1.001 => 148352
DRM derives these rates from the EDID CEA mode identifiers, which are
looked up in the tables in drivers/gpu/drm/drm_edid.c. The values on
the right are the clock values found in these tables, and are
currently expected to be passed to the HDMI driver unchanged.
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/gpu/drm/bridge')
| -rw-r--r-- | drivers/gpu/drm/bridge/dw_hdmi.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c index e5ee92370f49..2ef13d92eaae 100644 --- a/drivers/gpu/drm/bridge/dw_hdmi.c +++ b/drivers/gpu/drm/bridge/dw_hdmi.c @@ -230,11 +230,11 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk, switch (freq) { case 32000: - if (pixel_clk == 25170000) + if (pixel_clk == 25175000) n = (ratio == 150) ? 9152 : 4576; - else if (pixel_clk == 27020000) + else if (pixel_clk == 27027000) n = (ratio == 150) ? 8192 : 4096; - else if (pixel_clk == 74170000 || pixel_clk == 148350000) + else if (pixel_clk == 74176000 || pixel_clk == 148352000) n = 11648; else n = 4096; @@ -242,11 +242,11 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk, break; case 44100: - if (pixel_clk == 25170000) + if (pixel_clk == 25175000) n = 7007; - else if (pixel_clk == 74170000) + else if (pixel_clk == 74176000) n = 17836; - else if (pixel_clk == 148350000) + else if (pixel_clk == 148352000) n = (ratio == 150) ? 17836 : 8918; else n = 6272; @@ -254,13 +254,13 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk, break; case 48000: - if (pixel_clk == 25170000) + if (pixel_clk == 25175000) n = (ratio == 150) ? 9152 : 6864; - else if (pixel_clk == 27020000) + else if (pixel_clk == 27027000) n = (ratio == 150) ? 8192 : 6144; - else if (pixel_clk == 74170000) + else if (pixel_clk == 74176000) n = 11648; - else if (pixel_clk == 148350000) + else if (pixel_clk == 148352000) n = (ratio == 150) ? 11648 : 5824; else n = 6144; |