OMAPDSS: hdmi5: Change hdmi_wp idlemode to to no_idle for audio playback

Enabling idle mode during audio playback causes the glitches on OMAP5
HDMI. The TRM also suggests to use no-idle for HDMI audio playback.

This patch sets HDMI idle mode to no-idle for the duration of the
playback, and restores it back to original value afterwards.
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/fbdev/omap2/dss/hdmi.h

@@ -357,6 +357,7 @@ struct omap_hdmi {
 
 	struct platform_device *audio_pdev;
 	void (*audio_abort_cb)(struct device *dev);
+	int wp_idlemode;
 };
 
 #endif

drivers/video/fbdev/omap2/dss/hdmi5.c

@@ -607,6 +607,10 @@ static int hdmi_audio_start(struct device *dev)
 	WARN_ON(!hdmi_mode_has_audio(&hd->cfg));
 	WARN_ON(!hd->display_enabled);
 
+	/* No-idle while playing audio, store the old value */
+	hd->wp_idlemode = REG_GET(hdmi.wp.base, HDMI_WP_SYSCONFIG, 3, 2);
+	REG_FLD_MOD(hdmi.wp.base, HDMI_WP_SYSCONFIG, 1, 3, 2);
+
 	hdmi_wp_audio_enable(&hd->wp, true);
 	hdmi_wp_audio_core_req_enable(&hd->wp, true);
 
@@ -622,6 +626,9 @@ static void hdmi_audio_stop(struct device *dev)
 
 	hdmi_wp_audio_core_req_enable(&hd->wp, false);
 	hdmi_wp_audio_enable(&hd->wp, false);
+
+	/* Playback stopped, restore original idlemode */
+	REG_FLD_MOD(hdmi.wp.base, HDMI_WP_SYSCONFIG, hd->wp_idlemode, 3, 2);
 }
 
 static int hdmi_audio_config(struct device *dev,