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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-02-02 10:55:38 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-03-30 19:42:37 +0100
commit622494a3560b13e05c9f2049bfab8e7fb12c67a2 (patch)
tree179bdf7557f4defb5b078778da9da7ad59ccdc9d /drivers/gpu
parent6bcf495317857e4e4cfb2e6f57fa8230cedc1362 (diff)
downloadop-kernel-dev-622494a3560b13e05c9f2049bfab8e7fb12c67a2.zip
op-kernel-dev-622494a3560b13e05c9f2049bfab8e7fb12c67a2.tar.gz
drm: bridge/dw_hdmi: adjust n/cts setting order
Patch derived from one from Yakir Yang. Yakir Yang says: For Designerware HDMI, the following write sequence is recommended: 1. aud_n3 (set bit ncts_atomic_write if desired) 2. aud_cts3 (set CTS_manual and CTS value if desired/enabled) 3. aud_cts2 (required in CTS_manual) 4. aud_cts1 (required in CTS_manual) 5. aud_n3 (bit ncts_atomic_write with same value as in step 1.) 6. aud_n2 7. aud_n1 However, avoid the ncts_atomic_write_bit and CTS_manual settings in this patch, both of which are marked reserved in the iMX6 documentation. All iMX6 code in the wild seems to want CTS_manual cleared. Having requested clarification from FSL, it appears that neither of these bits are implemented in their version of the IP. Acked-by: Philipp Zabel <p.zabel@pengutronix.de> Tested-by: Philipp Zabel <p.zabel@pengutronix.de> Acked-by: Andy Yan <andy.yan@rock-chips.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/bridge/dw_hdmi.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c
index b75922d..cca1c3d1 100644
--- a/drivers/gpu/drm/bridge/dw_hdmi.c
+++ b/drivers/gpu/drm/bridge/dw_hdmi.c
@@ -182,20 +182,20 @@ static void hdmi_mask_writeb(struct dw_hdmi *hdmi, u8 data, unsigned int reg,
static void hdmi_set_cts_n(struct dw_hdmi *hdmi, unsigned int cts,
unsigned int n)
{
- hdmi_writeb(hdmi, n & 0xff, HDMI_AUD_N1);
- hdmi_writeb(hdmi, (n >> 8) & 0xff, HDMI_AUD_N2);
- hdmi_writeb(hdmi, (n >> 16) & 0x0f, HDMI_AUD_N3);
+ /* Must be set/cleared first */
+ hdmi_modb(hdmi, 0, HDMI_AUD_CTS3_CTS_MANUAL, HDMI_AUD_CTS3);
/* nshift factor = 0 */
hdmi_modb(hdmi, 0, HDMI_AUD_CTS3_N_SHIFT_MASK, HDMI_AUD_CTS3);
- /* Must be set/cleared first */
- hdmi_modb(hdmi, 0, HDMI_AUD_CTS3_CTS_MANUAL, HDMI_AUD_CTS3);
-
- hdmi_writeb(hdmi, cts & 0xff, HDMI_AUD_CTS1);
- hdmi_writeb(hdmi, (cts >> 8) & 0xff, HDMI_AUD_CTS2);
hdmi_writeb(hdmi, ((cts >> 16) & HDMI_AUD_CTS3_AUDCTS19_16_MASK) |
HDMI_AUD_CTS3_CTS_MANUAL, HDMI_AUD_CTS3);
+ hdmi_writeb(hdmi, (cts >> 8) & 0xff, HDMI_AUD_CTS2);
+ hdmi_writeb(hdmi, cts & 0xff, HDMI_AUD_CTS1);
+
+ hdmi_writeb(hdmi, (n >> 16) & 0x0f, HDMI_AUD_N3);
+ hdmi_writeb(hdmi, (n >> 8) & 0xff, HDMI_AUD_N2);
+ hdmi_writeb(hdmi, n & 0xff, HDMI_AUD_N1);
}
static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk,
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