[PATCH v2 04/12] drm/sun4i: sun6i_mipi_dsi: Simplify drq set to support all modes

[Jagan Teki <jagan@amarulasolutions.com>]

Allwinner MIPI DSI DRQ set value can be varied with respective
video modes.
- burst mode the set value is always 0
- video modes whose front porch greater than 20, the set value
  can be computed based front porch and bpp.
- video modes whose front porch is not greater than 20, the set value
  is simply 0

This patch simplifies existing drq set value code by grouping
into sun6i_dsi_get_drq and support all video modes.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 38 ++++++++++++++++----------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index efd08bfd0cb8..d60955880c43 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -363,6 +363,26 @@ static void sun6i_dsi_inst_init(struct sun6i_dsi *dsi,
 		     SUN6I_DSI_INST_JUMP_CFG_NUM(1));
 };
 
+static int sun6i_dsi_get_drq(struct sun6i_dsi *dsi,
+			      struct drm_display_mode *mode)
+{
+	struct mipi_dsi_device *device = dsi->device;
+	int drq = 0;
+
+	if (device->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
+		return drq;
+
+	if ((mode->hsync_start - mode->hdisplay) > 20) {
+		/* Maaaaaagic */
+		u16 drq = (mode->hsync_start - mode->hdisplay) - 20;
+
+		drq *= mipi_dsi_pixel_format_to_bpp(device->format);
+		drq /= 32;
+	}
+
+	return drq;
+}
+
 static u16 sun6i_dsi_get_timings_vblk(struct sun6i_dsi *dsi,
 				      struct drm_display_mode *mode, u16 hblk)
 {
@@ -478,21 +498,9 @@ static u16 sun6i_dsi_get_video_start_delay(struct sun6i_dsi *dsi,
 static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi,
 				  struct drm_display_mode *mode)
 {
-	struct mipi_dsi_device *device = dsi->device;
-	u32 val = 0;
-
-	if ((mode->hsync_start - mode->hdisplay) > 20) {
-		/* Maaaaaagic */
-		u16 drq = (mode->hsync_start - mode->hdisplay) - 20;
-
-		drq *= mipi_dsi_pixel_format_to_bpp(device->format);
-		drq /= 32;
-
-		val = (SUN6I_DSI_TCON_DRQ_ENABLE_MODE |
-		       SUN6I_DSI_TCON_DRQ_SET(drq));
-	}
-
-	regmap_write(dsi->regs, SUN6I_DSI_TCON_DRQ_REG, val);
+	regmap_write(dsi->regs, SUN6I_DSI_TCON_DRQ_REG,
+		     SUN6I_DSI_TCON_DRQ_ENABLE_MODE |
+		     SUN6I_DSI_TCON_DRQ_SET(sun6i_dsi_get_drq(dsi, mode)));
 }
 
 static void sun6i_dsi_setup_inst_loop(struct sun6i_dsi *dsi,
-- 
2.18.0.321.gffc6fa0e3