linux-kernel - [PATCH v4 20/78] drm/vc4: crtc: Turn pixelvalve reset into a function

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Message-Id: <0c7774f65f428a63d2e615ac823494393e80db71.1594230107.git-series.maxime@cerno.tech>
Date:   Wed,  8 Jul 2020 19:41:28 +0200
From:   Maxime Ripard <maxime@...no.tech>
To:     Nicolas Saenz Julienne <nsaenzjulienne@...e.de>,
        Eric Anholt <eric@...olt.net>
Cc:     dri-devel@...ts.freedesktop.org,
        linux-rpi-kernel@...ts.infradead.org,
        bcm-kernel-feedback-list@...adcom.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Dave Stevenson <dave.stevenson@...pberrypi.com>,
        Tim Gover <tim.gover@...pberrypi.com>,
        Phil Elwell <phil@...pberrypi.com>,
        Maxime Ripard <maxime@...no.tech>
Subject: [PATCH v4 20/78] drm/vc4: crtc: Turn pixelvalve reset into a function

The driver resets the pixelvalve FIFO in a number of occurences without
always using the same sequence.

Since this will be critical for BCM2711, let's move that sequence to a
function so that we are consistent.

Reviewed-by: Eric Anholt <eric@...olt.net>
Signed-off-by: Maxime Ripard <maxime@...no.tech>
---
 drivers/gpu/drm/vc4/vc4_crtc.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 41bc61d5a61f..c2ab907611e3 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -267,6 +267,15 @@ static struct drm_encoder *vc4_get_crtc_encoder(struct drm_crtc *crtc)
 	return NULL;
 }
 
+static void vc4_crtc_pixelvalve_reset(struct drm_crtc *crtc)
+{
+	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+
+	/* The PV needs to be disabled before it can be flushed */
+	CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) & ~PV_CONTROL_EN);
+	CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) | PV_CONTROL_FIFO_CLR);
+}
+
 static void vc4_crtc_config_pv(struct drm_crtc *crtc)
 {
 	struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc);
@@ -282,10 +291,7 @@ static void vc4_crtc_config_pv(struct drm_crtc *crtc)
 	u32 format = is_dsi ? PV_CONTROL_FORMAT_DSIV_24 : PV_CONTROL_FORMAT_24;
 	u8 ppc = pv_data->pixels_per_clock;
 
-	/* Reset the PV fifo. */
-	CRTC_WRITE(PV_CONTROL, 0);
-	CRTC_WRITE(PV_CONTROL, PV_CONTROL_FIFO_CLR | PV_CONTROL_EN);
-	CRTC_WRITE(PV_CONTROL, 0);
+	vc4_crtc_pixelvalve_reset(crtc);
 
 	CRTC_WRITE(PV_HORZA,
 		   VC4_SET_FIELD((mode->htotal - mode->hsync_end) * pixel_rep / ppc,
@@ -430,9 +436,9 @@ static void vc4_crtc_atomic_enable(struct drm_crtc *crtc,
 
 	require_hvs_enabled(dev);
 
-	/* Reset the PV fifo. */
-	CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) |
-		   PV_CONTROL_FIFO_CLR | PV_CONTROL_EN);
+	vc4_crtc_pixelvalve_reset(crtc);
+
+	CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) | PV_CONTROL_EN);
 
 	/* Enable vblank irq handling before crtc is started otherwise
 	 * drm_crtc_get_vblank() fails in vc4_crtc_update_dlist().
-- 
git-series 0.9.1