[PATCH 12/17] drm/mgag200: Move TAGFIFO reset into separate function

[Thomas Zimmermann]

The TAGFIFO state is now reset in mgag200_g200er_reset_tagfifo().

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 drivers/gpu/drm/mgag200/mgag200_drv.h  |  6 ++++
 drivers/gpu/drm/mgag200/mgag200_mode.c | 45 +++++++++++++++++---------
 2 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.h b/drivers/gpu/drm/mgag200/mgag200_drv.h
index 9b957d9fc7e04..b10da90e0f35a 100644
--- a/drivers/gpu/drm/mgag200/mgag200_drv.h
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.h
@@ -49,6 +49,12 @@
 		WREG8(ATTR_DATA, v);				\
 	} while (0)						\
 
+#define RREG_SEQ(reg, v)					\
+	do {							\
+		WREG8(MGAREG_SEQ_INDEX, reg);			\
+		v = RREG8(MGAREG_SEQ_DATA);			\
+	} while (0)						\
+
 #define WREG_SEQ(reg, v)					\
 	do {							\
 		WREG8(MGAREG_SEQ_INDEX, reg);			\
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 73f7135cbb3d8..6b88c306ff4d7 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -1091,6 +1091,33 @@ static void mgag200_set_format_regs(struct mga_device *mdev,
 	WREG_ECRT(3, crtcext3);
 }
 
+static void mgag200_g200er_reset_tagfifo(struct mga_device *mdev)
+{
+	static uint32_t RESET_FLAG = 0x00200000; /* undocumented magic value */
+	u8 seq1;
+	u32 memctl;
+
+	/* screen off */
+	RREG_SEQ(0x01, seq1);
+	seq1 |= 0x20;
+	WREG_SEQ(0x01, seq1);
+
+	memctl = RREG32(MGAREG_MEMCTL);
+
+	memctl |= RESET_FLAG;
+	WREG32(MGAREG_MEMCTL, memctl);
+
+	udelay(1000);
+
+	memctl &= ~RESET_FLAG;
+	WREG32(MGAREG_MEMCTL, memctl);
+
+	/* screen on */
+	RREG_SEQ(0x01, seq1);
+	seq1 &= ~0x20;
+	WREG_SEQ(0x01, seq1);
+}
+
 static int mga_crtc_mode_set(struct drm_crtc *crtc,
 				struct drm_display_mode *mode,
 				struct drm_display_mode *adjusted_mode,
@@ -1225,22 +1252,8 @@ static int mga_crtc_mode_set(struct drm_crtc *crtc,
 
 	mgag200_set_mode_regs(mdev, mode);
 
-	/* reset tagfifo */
-	if (mdev->type == G200_ER) {
-		u32 mem_ctl = RREG32(MGAREG_MEMCTL);
-		u8 seq1;
-
-		/* screen off */
-		WREG8(MGAREG_SEQ_INDEX, 0x01);
-		seq1 = RREG8(MGAREG_SEQ_DATA) | 0x20;
-		WREG8(MGAREG_SEQ_DATA, seq1);
-
-		WREG32(MGAREG_MEMCTL, mem_ctl | 0x00200000);
-		udelay(1000);
-		WREG32(MGAREG_MEMCTL, mem_ctl & ~0x00200000);
-
-		WREG8(MGAREG_SEQ_DATA, seq1 & ~0x20);
-	}
+	if (mdev->type == G200_ER)
+		mgag200_g200er_reset_tagfifo(mdev);
 
 
 	if (IS_G200_SE(mdev)) {
-- 
2.26.0