drm/fsl-dcu: remove regmap return value checks

It is not common to do regmap return value checks, especially not
for memory mapped device. We can rule out most error returns since
the conditions are static and we know they are ok (e.g. offset
aligned to register stride). Also without proper error handling
they are not really valuable for the user. Hence remove most of
them.

The check in the interrupt handler is worth keeping since a
volatile register won't be readable in case register caching is
still enabled.

Signed-off-by: Stefan Agner <stefan@agner.ch>

1 files changed, 41 insertions, 83 deletions

diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
index d8ab8f0af10c..f0285c41b29c 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
@@ -42,34 +42,24 @@ static void fsl_dcu_drm_disable_crtc(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
 	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
-	int ret;
 
-	ret = regmap_update_bits(fsl_dev->regmap, DCU_DCU_MODE,
-				 DCU_MODE_DCU_MODE_MASK,
-				 DCU_MODE_DCU_MODE(DCU_MODE_OFF));
-	if (ret)
-		dev_err(fsl_dev->dev, "Disable CRTC failed\n");
-	ret = regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE,
-			   DCU_UPDATE_MODE_READREG);
-	if (ret)
-		dev_err(fsl_dev->dev, "Enable CRTC failed\n");
+	regmap_update_bits(fsl_dev->regmap, DCU_DCU_MODE,
+			   DCU_MODE_DCU_MODE_MASK,
+			   DCU_MODE_DCU_MODE(DCU_MODE_OFF));
+	regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE,
+		     DCU_UPDATE_MODE_READREG);
 }
 
 static void fsl_dcu_drm_crtc_enable(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
 	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
-	int ret;
 
-	ret = regmap_update_bits(fsl_dev->regmap, DCU_DCU_MODE,
-				 DCU_MODE_DCU_MODE_MASK,
-				 DCU_MODE_DCU_MODE(DCU_MODE_NORMAL));
-	if (ret)
-		dev_err(fsl_dev->dev, "Enable CRTC failed\n");
-	ret = regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE,
-			   DCU_UPDATE_MODE_READREG);
-	if (ret)
-		dev_err(fsl_dev->dev, "Enable CRTC failed\n");
+	regmap_update_bits(fsl_dev->regmap, DCU_DCU_MODE,
+			   DCU_MODE_DCU_MODE_MASK,
+			   DCU_MODE_DCU_MODE(DCU_MODE_NORMAL));
+	regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE,
+		     DCU_UPDATE_MODE_READREG);
 }
 
 static bool fsl_dcu_drm_crtc_mode_fixup(struct drm_crtc *crtc,
@@ -86,7 +76,6 @@ static void fsl_dcu_drm_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	struct drm_display_mode *mode = &crtc->state->mode;
 	unsigned int hbp, hfp, hsw, vbp, vfp, vsw, div, index;
 	unsigned long dcuclk;
-	int ret;
 
 	index = drm_crtc_index(crtc);
 	dcuclk = clk_get_rate(fsl_dev->clk);
@@ -100,51 +89,31 @@ static void fsl_dcu_drm_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	vfp = mode->vsync_start - mode->vdisplay;
 	vsw = mode->vsync_end - mode->vsync_start;
 
-	ret = regmap_write(fsl_dev->regmap, DCU_HSYN_PARA,
-			   DCU_HSYN_PARA_BP(hbp) |
-			   DCU_HSYN_PARA_PW(hsw) |
-			   DCU_HSYN_PARA_FP(hfp));
-	if (ret)
-		goto set_failed;
-	ret = regmap_write(fsl_dev->regmap, DCU_VSYN_PARA,
-			   DCU_VSYN_PARA_BP(vbp) |
-			   DCU_VSYN_PARA_PW(vsw) |
-			   DCU_VSYN_PARA_FP(vfp));
-	if (ret)
-		goto set_failed;
-	ret = regmap_write(fsl_dev->regmap, DCU_DISP_SIZE,
-			   DCU_DISP_SIZE_DELTA_Y(mode->vdisplay) |
-			   DCU_DISP_SIZE_DELTA_X(mode->hdisplay));
-	if (ret)
-		goto set_failed;
-	ret = regmap_write(fsl_dev->regmap, DCU_DIV_RATIO, div);
-	if (ret)
-		goto set_failed;
-	ret = regmap_write(fsl_dev->regmap, DCU_SYN_POL,
-			   DCU_SYN_POL_INV_VS_LOW | DCU_SYN_POL_INV_HS_LOW);
-	if (ret)
-		goto set_failed;
-	ret = regmap_write(fsl_dev->regmap, DCU_BGND, DCU_BGND_R(0) |
-			   DCU_BGND_G(0) | DCU_BGND_B(0));
-	if (ret)
-		goto set_failed;
-	ret = regmap_write(fsl_dev->regmap, DCU_DCU_MODE,
-			   DCU_MODE_BLEND_ITER(1) | DCU_MODE_RASTER_EN);
-	if (ret)
-		goto set_failed;
-	ret = regmap_write(fsl_dev->regmap, DCU_THRESHOLD,
-			   DCU_THRESHOLD_LS_BF_VS(BF_VS_VAL) |
-			   DCU_THRESHOLD_OUT_BUF_HIGH(BUF_MAX_VAL) |
-			   DCU_THRESHOLD_OUT_BUF_LOW(BUF_MIN_VAL));
-	if (ret)
-		goto set_failed;
-	ret = regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE,
-			   DCU_UPDATE_MODE_READREG);
-	if (ret)
-		goto set_failed;
+	regmap_write(fsl_dev->regmap, DCU_HSYN_PARA,
+		     DCU_HSYN_PARA_BP(hbp) |
+		     DCU_HSYN_PARA_PW(hsw) |
+		     DCU_HSYN_PARA_FP(hfp));
+	regmap_write(fsl_dev->regmap, DCU_VSYN_PARA,
+		     DCU_VSYN_PARA_BP(vbp) |
+		     DCU_VSYN_PARA_PW(vsw) |
+		     DCU_VSYN_PARA_FP(vfp));
+	regmap_write(fsl_dev->regmap, DCU_DISP_SIZE,
+		     DCU_DISP_SIZE_DELTA_Y(mode->vdisplay) |
+		     DCU_DISP_SIZE_DELTA_X(mode->hdisplay));
+	regmap_write(fsl_dev->regmap, DCU_DIV_RATIO, div);
+	regmap_write(fsl_dev->regmap, DCU_SYN_POL,
+		     DCU_SYN_POL_INV_VS_LOW | DCU_SYN_POL_INV_HS_LOW);
+	regmap_write(fsl_dev->regmap, DCU_BGND, DCU_BGND_R(0) |
+		     DCU_BGND_G(0) | DCU_BGND_B(0));
+	regmap_write(fsl_dev->regmap, DCU_DCU_MODE,
+		     DCU_MODE_BLEND_ITER(1) | DCU_MODE_RASTER_EN);
+	regmap_write(fsl_dev->regmap, DCU_THRESHOLD,
+		     DCU_THRESHOLD_LS_BF_VS(BF_VS_VAL) |
+		     DCU_THRESHOLD_OUT_BUF_HIGH(BUF_MAX_VAL) |
+		     DCU_THRESHOLD_OUT_BUF_LOW(BUF_MIN_VAL));
+	regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE,
+		     DCU_UPDATE_MODE_READREG);
 	return;
-set_failed:
-	dev_err(dev->dev, "set DCU register failed\n");
 }
 
 static const struct drm_crtc_helper_funcs fsl_dcu_drm_crtc_helper_funcs = {
@@ -186,25 +155,14 @@ int fsl_dcu_drm_crtc_create(struct fsl_dcu_drm_device *fsl_dev)
 	else
 		reg_num = VF610_LAYER_REG_NUM;
 	for (i = 0; i <= fsl_dev->soc->total_layer; i++) {
-		for (j = 0; j < reg_num; j++) {
-			ret = regmap_write(fsl_dev->regmap,
-					   DCU_CTRLDESCLN(i, j), 0);
-			if (ret)
-				goto init_failed;
-		}
+		for (j = 0; j < reg_num; j++)
+			regmap_write(fsl_dev->regmap, DCU_CTRLDESCLN(i, j), 0);
 	}
-	ret = regmap_update_bits(fsl_dev->regmap, DCU_DCU_MODE,
-				 DCU_MODE_DCU_MODE_MASK,
-				 DCU_MODE_DCU_MODE(DCU_MODE_OFF));
-	if (ret)
-		goto init_failed;
-	ret = regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE,
-			   DCU_UPDATE_MODE_READREG);
-	if (ret)
-		goto init_failed;
+	regmap_update_bits(fsl_dev->regmap, DCU_DCU_MODE,
+			   DCU_MODE_DCU_MODE_MASK,
+			   DCU_MODE_DCU_MODE(DCU_MODE_OFF));
+	regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE,
+		     DCU_UPDATE_MODE_READREG);
 
 	return 0;
-init_failed:
-	dev_err(fsl_dev->dev, "init DCU register failed\n");
-	return ret;
 }