drm: aspeed: Debugfs interface for GFX registers

This exposes the GFX registers in debugfs for debugging. The idea is
borrowed from the Broadcom driver.

OpenBMC-Staging-Count: 1
Signed-off-by: Joel Stanley <joel@jms.id.au>

4 files changed, 83 insertions, 0 deletions

diff --git a/drivers/gpu/drm/aspeed/Makefile b/drivers/gpu/drm/aspeed/Makefile
index 6e194cd790d8..b01dd5800672 100644
--- a/drivers/gpu/drm/aspeed/Makefile
+++ b/drivers/gpu/drm/aspeed/Makefile
@@ -1,3 +1,4 @@
 aspeed_gfx-y := aspeed_gfx_drv.o aspeed_gfx_crtc.o aspeed_gfx_out.o
+aspeed_gfx-$(CONFIG_DEBUG_FS) += aspeed_gfx_debugfs.o
 
 obj-$(CONFIG_DRM_ASPEED_GFX) += aspeed_gfx.o
diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx.h b/drivers/gpu/drm/aspeed/aspeed_gfx.h
index fb56e425bd48..c46afb3398cb 100644
--- a/drivers/gpu/drm/aspeed/aspeed_gfx.h
+++ b/drivers/gpu/drm/aspeed/aspeed_gfx.h
@@ -17,6 +17,7 @@ struct aspeed_gfx {
 
 int aspeed_gfx_create_pipe(struct drm_device *drm);
 int aspeed_gfx_create_output(struct drm_device *drm);
+int aspeed_gfx_debugfs_init(struct drm_minor *minor);
 
 #define CRT_CTRL1		0x60 /* CRT Control I */
 #define CRT_CTRL2		0x64 /* CRT Control II */
diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx_debugfs.c b/drivers/gpu/drm/aspeed/aspeed_gfx_debugfs.c
new file mode 100644
index 000000000000..ac47c27d8e74
--- /dev/null
+++ b/drivers/gpu/drm/aspeed/aspeed_gfx_debugfs.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright © 2017 Broadcom
+// Copyright 2018 IBM Corp
+
+#include <linux/seq_file.h>
+#include <drm/drm_debugfs.h>
+
+#include "aspeed_gfx.h"
+
+#define REGDEF(reg) { reg, #reg }
+static const struct {
+	u32 reg;
+	const char *name;
+} aspeed_gfx_reg_defs[] = {
+	REGDEF(CRT_CTRL1),
+	REGDEF(CRT_CTRL2),
+	REGDEF(CRT_STATUS),
+	REGDEF(CRT_MISC),
+	REGDEF(CRT_HORIZ0),
+	REGDEF(CRT_HORIZ1),
+	REGDEF(CRT_VERT0),
+	REGDEF(CRT_VERT1),
+	REGDEF(CRT_ADDR),
+	REGDEF(CRT_OFFSET),
+	REGDEF(CRT_THROD),
+	REGDEF(CRT_XSCALE),
+	REGDEF(CRT_CURSOR0),
+	REGDEF(CRT_CURSOR1),
+	REGDEF(CRT_CURSOR2),
+	REGDEF(CRT_9C),
+	REGDEF(CRT_OSD_H),
+	REGDEF(CRT_OSD_V),
+	REGDEF(CRT_OSD_ADDR),
+	REGDEF(CRT_OSD_DISP),
+	REGDEF(CRT_OSD_THRESH),
+	REGDEF(CRT_B4),
+	REGDEF(CRT_STS_V),
+	REGDEF(CRT_SCRATCH),
+	REGDEF(CRT_BB0_ADDR),
+	REGDEF(CRT_BB1_ADDR),
+	REGDEF(CRT_BB_COUNT),
+	REGDEF(OSD_COLOR1),
+	REGDEF(OSD_COLOR2),
+	REGDEF(OSD_COLOR3),
+	REGDEF(OSD_COLOR4),
+	REGDEF(OSD_COLOR5),
+	REGDEF(OSD_COLOR6),
+	REGDEF(OSD_COLOR7),
+	REGDEF(OSD_COLOR8),
+};
+
+int aspeed_gfx_debugfs_regs(struct seq_file *m, void *unused)
+{
+	struct drm_info_node *node = (struct drm_info_node *)m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct aspeed_gfx *priv = dev->dev_private;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(aspeed_gfx_reg_defs); i++) {
+		seq_printf(m, "%15s (0x%02x): 0x%08x\n",
+			   aspeed_gfx_reg_defs[i].name, aspeed_gfx_reg_defs[i].reg,
+			   readl(priv->base + aspeed_gfx_reg_defs[i].reg));
+	}
+
+	return 0;
+}
+
+static const struct drm_info_list aspeed_gfx_debugfs_list[] = {
+	{"regs", aspeed_gfx_debugfs_regs, 0},
+};
+
+int aspeed_gfx_debugfs_init(struct drm_minor *minor)
+{
+	return drm_debugfs_create_files(aspeed_gfx_debugfs_list,
+					ARRAY_SIZE(aspeed_gfx_debugfs_list),
+					minor->debugfs_root, minor);
+}
diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
index e53d84b97d54..e2db7ddcb53c 100644
--- a/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
+++ b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
@@ -200,6 +200,10 @@ static struct drm_driver aspeed_gfx_driver = {
 	.date = "20180319",
 	.major = 1,
 	.minor = 0,
+
+#if defined(CONFIG_DEBUG_FS)
+	.debugfs_init = aspeed_gfx_debugfs_init,
+#endif
 };
 
 static const struct of_device_id aspeed_gfx_match[] = {