[PATCH v4 14/21] media: rkisp1: debug: Collect input status by sampling ISP_FLAGS_SHD

[Laurent Pinchart]

The ISP_FLAGS_SHD register exposes the ISP parallel input signals (data
and synchronization) in real time. This can help debugging when the
device doesn't output any image. Sample the register 10000 times with a
1µs delay and expose the result through debugfs.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
---
Changes since v3:

- Fix pm_runtime_get_if_in_use() return value handling

Changes since v2:

- Handle runtime PM
---
 .../platform/rockchip/rkisp1/rkisp1-debug.c   | 54 +++++++++++++++++++
 .../platform/rockchip/rkisp1/rkisp1-regs.h    |  9 ++++
 2 files changed, 63 insertions(+)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-debug.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-debug.c
index 64b33774cbdf..782a696ac587 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-debug.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-debug.c
@@ -9,9 +9,61 @@
  */
 
 #include <linux/debugfs.h>
+#include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/pm_runtime.h>
+#include <linux/seq_file.h>
 
 #include "rkisp1-common.h"
+#include "rkisp1-regs.h"
+
+#define RKISP1_DEBUG_DATA_COUNT_BINS	32
+#define RKISP1_DEBUG_DATA_COUNT_STEP	(4096 / RKISP1_DEBUG_DATA_COUNT_BINS)
+
+static int rkisp1_debug_input_status_show(struct seq_file *m, void *p)
+{
+	struct rkisp1_device *rkisp1 = m->private;
+	u16 data_count[RKISP1_DEBUG_DATA_COUNT_BINS] = { };
+	unsigned int hsync_count = 0;
+	unsigned int vsync_count = 0;
+	unsigned int i;
+	u32 data;
+	u32 val;
+	int ret;
+
+	ret = pm_runtime_get_if_in_use(rkisp1->dev);
+	if (ret <= 0)
+		return ret ? : -ENODATA;
+
+	/* Sample the ISP input port status 10000 times with a 1µs interval. */
+	for (i = 0; i < 10000; ++i) {
+		val = rkisp1_read(rkisp1, RKISP1_CIF_ISP_FLAGS_SHD);
+
+		data = (val & RKISP1_CIF_ISP_FLAGS_SHD_S_DATA_MASK)
+		     >> RKISP1_CIF_ISP_FLAGS_SHD_S_DATA_SHIFT;
+		data_count[data / RKISP1_DEBUG_DATA_COUNT_STEP]++;
+
+		if (val & RKISP1_CIF_ISP_FLAGS_SHD_S_HSYNC)
+			hsync_count++;
+		if (val & RKISP1_CIF_ISP_FLAGS_SHD_S_VSYNC)
+			vsync_count++;
+
+		udelay(1);
+	}
+
+	pm_runtime_put(rkisp1->dev);
+
+	seq_printf(m, "vsync: %u, hsync: %u\n", vsync_count, hsync_count);
+	seq_puts(m, "data:\n");
+	for (i = 0; i < ARRAY_SIZE(data_count); ++i)
+		seq_printf(m, "- [%04u:%04u]: %u\n",
+			   i * RKISP1_DEBUG_DATA_COUNT_STEP,
+			   (i + 1) * RKISP1_DEBUG_DATA_COUNT_STEP - 1,
+			   data_count[i]);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(rkisp1_debug_input_status);
 
 void rkisp1_debug_init(struct rkisp1_device *rkisp1)
 {
@@ -42,6 +94,8 @@ void rkisp1_debug_init(struct rkisp1_device *rkisp1)
 			     &debug->frame_drop[RKISP1_MAINPATH]);
 	debugfs_create_ulong("sp_frame_drop", 0444, debug->debugfs_dir,
 			     &debug->frame_drop[RKISP1_SELFPATH]);
+	debugfs_create_file("input_status", 0444, debug->debugfs_dir, rkisp1,
+			    &rkisp1_debug_input_status_fops);
 }
 
 void rkisp1_debug_cleanup(struct rkisp1_device *rkisp1)
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-regs.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-regs.h
index a93d0127b813..2b322db97252 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-regs.h
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-regs.h
@@ -454,6 +454,15 @@
 #define RKISP1_CIF_ISP_DEMOSAIC_BYPASS			BIT(10)
 #define RKISP1_CIF_ISP_DEMOSAIC_TH(x)			((x) & 0xFF)
 
+/* ISP_FLAGS_SHD */
+#define RKISP1_CIF_ISP_FLAGS_SHD_ISP_ENABLE_SHD		BIT(0)
+#define RKISP1_CIF_ISP_FLAGS_SHD_ISP_ENABLE_INFORM_SHD	BIT(1)
+#define RKISP1_CIF_ISP_FLAGS_SHD_INFORM_FIELD		BIT(2)
+#define RKISP1_CIF_ISP_FLAGS_SHD_S_DATA_MASK		GENMASK(27, 16)
+#define RKISP1_CIF_ISP_FLAGS_SHD_S_DATA_SHIFT		16
+#define RKISP1_CIF_ISP_FLAGS_SHD_S_VSYNC		BIT(30)
+#define RKISP1_CIF_ISP_FLAGS_SHD_S_HSYNC		BIT(31)
+
 /* AWB */
 /* ISP_AWB_PROP */
 #define RKISP1_CIF_ISP_AWB_YMAX_CMP_EN			BIT(2)
-- 
Regards,

Laurent Pinchart