drm/msm/dpu: simplify DPU's regset32 code

Squash dpu_debugfs_setup_regset32() into dpu_debugfs_create_regset32().
it makes little sense to have separate function to just setup the
structure.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Link: https://lore.kernel.org/r/20211201222633.2476780-8-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c

@@ -182,6 +182,15 @@ static void dpu_debugfs_danger_init(struct dpu_kms *dpu_kms,
 
 }
 
+/*
+ * Companion structure for dpu_debugfs_create_regset32.
+ */
+struct dpu_debugfs_regset32 {
+	uint32_t offset;
+	uint32_t blk_len;
+	struct dpu_kms *dpu_kms;
+};
+
 static int _dpu_debugfs_show_regset32(struct seq_file *s, void *data)
 {
 	struct dpu_debugfs_regset32 *regset = s->private;
@@ -229,24 +238,23 @@ static const struct file_operations dpu_fops_regset32 = {
 	.release =	single_release,
 };
 
-void dpu_debugfs_setup_regset32(struct dpu_debugfs_regset32 *regset,
+void dpu_debugfs_create_regset32(const char *name, umode_t mode,
+		void *parent,
 		uint32_t offset, uint32_t length, struct dpu_kms *dpu_kms)
 {
-	if (regset) {
-		regset->offset = offset;
-		regset->blk_len = length;
-		regset->dpu_kms = dpu_kms;
-	}
-}
+	struct dpu_debugfs_regset32 *regset;
 
-void dpu_debugfs_create_regset32(const char *name, umode_t mode,
-		void *parent, struct dpu_debugfs_regset32 *regset)
-{
-	if (!name || !regset || !regset->dpu_kms || !regset->blk_len)
+	if (WARN_ON(!name || !dpu_kms || !length))
+		return;
+
+	regset = devm_kzalloc(&dpu_kms->pdev->dev, sizeof(*regset), GFP_KERNEL);
+	if (!regset)
 		return;
 
 	/* make sure offset is a multiple of 4 */
-	regset->offset = round_down(regset->offset, 4);
+	regset->offset = round_down(offset, 4);
+	regset->blk_len = length;
+	regset->dpu_kms = dpu_kms;
 
 	debugfs_create_file(name, mode, parent, regset, &dpu_fops_regset32);
 }

drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h

@@ -160,33 +160,9 @@ struct dpu_global_state
  *
  * Documentation/filesystems/debugfs.rst
  *
- * @dpu_debugfs_setup_regset32: Initialize data for dpu_debugfs_create_regset32
  * @dpu_debugfs_create_regset32: Create 32-bit register dump file
- * @dpu_debugfs_get_root: Get root dentry for DPU_KMS's debugfs node
  */
 
-/**
- * Companion structure for dpu_debugfs_create_regset32. Do not initialize the
- * members of this structure explicitly; use dpu_debugfs_setup_regset32 instead.
- */
-struct dpu_debugfs_regset32 {
-	uint32_t offset;
-	uint32_t blk_len;
-	struct dpu_kms *dpu_kms;
-};
-
-/**
- * dpu_debugfs_setup_regset32 - Initialize register block definition for debugfs
- * This function is meant to initialize dpu_debugfs_regset32 structures for use
- * with dpu_debugfs_create_regset32.
- * @regset: opaque register definition structure
- * @offset: sub-block offset
- * @length: sub-block length, in bytes
- * @dpu_kms: pointer to dpu kms structure
- */
-void dpu_debugfs_setup_regset32(struct dpu_debugfs_regset32 *regset,
-		uint32_t offset, uint32_t length, struct dpu_kms *dpu_kms);
-
 /**
  * dpu_debugfs_create_regset32 - Create register read back file for debugfs
  *
@@ -195,20 +171,16 @@ void dpu_debugfs_setup_regset32(struct dpu_debugfs_regset32 *regset,
  * names/offsets do not need to be provided. The 'read' function simply outputs
  * sequential register values over a specified range.
  *
- * Similar to the related debugfs_create_regset32 API, the structure pointed to
- * by regset needs to persist for the lifetime of the created file. The calling
- * code is responsible for initialization/management of this structure.
- *
- * The structure pointed to by regset is meant to be opaque. Please use
- * dpu_debugfs_setup_regset32 to initialize it.
- *
  * @name:   File name within debugfs
  * @mode:   File mode within debugfs
  * @parent: Parent directory entry within debugfs, can be NULL
- * @regset: Pointer to persistent register block definition
+ * @offset: sub-block offset
+ * @length: sub-block length, in bytes
+ * @dpu_kms: pointer to dpu kms structure
  */
 void dpu_debugfs_create_regset32(const char *name, umode_t mode,
-		void *parent, struct dpu_debugfs_regset32 *regset);
+		void *parent,
+		uint32_t offset, uint32_t length, struct dpu_kms *dpu_kms);
 
 /**
  * dpu_debugfs_get_root - Return root directory entry for KMS's debugfs

drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c

@@ -108,11 +108,6 @@ struct dpu_plane {
 	bool is_virtual;
 	struct list_head mplane_list;
 	struct dpu_mdss_cfg *catalog;
-
-	/* debugfs related stuff */
-	struct dpu_debugfs_regset32 debugfs_src;
-	struct dpu_debugfs_regset32 debugfs_scaler;
-	struct dpu_debugfs_regset32 debugfs_csc;
 };
 
 static const uint64_t supported_format_modifiers[] = {
@@ -1371,35 +1366,29 @@ static int _dpu_plane_init_debugfs(struct drm_plane *plane)
 			debugfs_root, (unsigned long *)&pdpu->pipe_hw->cap->features);
 
 	/* add register dump support */
-	dpu_debugfs_setup_regset32(&pdpu->debugfs_src,
+	dpu_debugfs_create_regset32("src_blk", 0400,
+			debugfs_root,
 			sblk->src_blk.base + cfg->base,
 			sblk->src_blk.len,
 			kms);
-	dpu_debugfs_create_regset32("src_blk", 0400,
-			debugfs_root, &pdpu->debugfs_src);
 
 	if (cfg->features & BIT(DPU_SSPP_SCALER_QSEED3) ||
 			cfg->features & BIT(DPU_SSPP_SCALER_QSEED3LITE) ||
 			cfg->features & BIT(DPU_SSPP_SCALER_QSEED2) ||
-			cfg->features & BIT(DPU_SSPP_SCALER_QSEED4)) {
-		dpu_debugfs_setup_regset32(&pdpu->debugfs_scaler,
+			cfg->features & BIT(DPU_SSPP_SCALER_QSEED4))
+		dpu_debugfs_create_regset32("scaler_blk", 0400,
+				debugfs_root,
 				sblk->scaler_blk.base + cfg->base,
 				sblk->scaler_blk.len,
 				kms);
-		dpu_debugfs_create_regset32("scaler_blk", 0400,
-				debugfs_root,
-				&pdpu->debugfs_scaler);
-	}
 
 	if (cfg->features & BIT(DPU_SSPP_CSC) ||
-			cfg->features & BIT(DPU_SSPP_CSC_10BIT)) {
-		dpu_debugfs_setup_regset32(&pdpu->debugfs_csc,
+			cfg->features & BIT(DPU_SSPP_CSC_10BIT))
+		dpu_debugfs_create_regset32("csc_blk", 0400,
+				debugfs_root,
 				sblk->csc_blk.base + cfg->base,
 				sblk->csc_blk.len,
 				kms);
-		dpu_debugfs_create_regset32("csc_blk", 0400,
-				debugfs_root, &pdpu->debugfs_csc);
-	}
 
 	debugfs_create_u32("xin_id",
 			0400,