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

[Ricardo Ribalda <ribalda@chromium.org>]

Laurent Pinchart wrote:

> 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.

I think this is quite clever :)

Out of curiosity, how long does reading the debug file takes?

> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
> 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
> 
>