[PATCH v6 0/2] Enable support for error detection in CSI2RX

[PATCH v6 0/2] Enable support for error detection in CSI2RX

[Yemike Abhilash Chandra]

This patch series enables the csi2rx_err_irq interrupt to record any errors
that occur during streaming. It also adds support for the VIDIOC_LOG_STATUS
ioctl, which outputs the current device status to the kernel log.

The IRQ handler records any errors encountered during streaming.
Additionally, VIDIOC_LOG_STATUS can be invoked from user space to retrieve
the latest status.

Changelog:
Changes in v6:
- Although the interrupt mask is configured only for cdns-csi2rx source pads
  with active remote connections, the IRQ handler currently records all events
  regardless of whether they are enabled in the mask. Since the events are not
  mutually exclusive, a stream overflow event for a pad without an active remote
  can be recorded if it occurs in parallel with any event enabled in the mask.
  To avoid this, update the handler to record only those events that are explicitly
  enabled in the mask, preventing unnecessary logging for pads without an active
  remote connection.
- Drop the Reviewed-by and Tested-by tags from Jai and Changhuang, as this
  version introduces a minor change in the IRQ handling logic.

v5: https://lore.kernel.org/all/20250228114030.1028443-1-y-abhilashchandra@ti.com/

Yemike Abhilash Chandra (2):
  dt-bindings: media: cdns,csi2rx.yaml: Add optional interrupts for
    cdns-csi2rx
  media: cadence: csi2rx: Enable csi2rx_err_irq interrupt and add
    support for VIDIOC_LOG_STATUS

 .../bindings/media/cdns,csi2rx.yaml           |   8 ++
 drivers/media/platform/cadence/cdns-csi2rx.c  | 131 ++++++++++++++++++
 2 files changed, 139 insertions(+)

-- 
2.34.1

[PATCH v6 1/2] dt-bindings: media: cdns,csi2rx.yaml: Add optional interrupts for cdns-csi2rx

[Yemike Abhilash Chandra]

The Cadence CSI2RX IP exposes 2 interrupts [0] 12.7 camera subsystem.
So, add support for optional interrupts and interrupt-names properties.

[0]: http://www.ti.com/lit/pdf/spruil1

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Jai Luthra <jai.luthra@linux.dev>
Signed-off-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
---
 Documentation/devicetree/bindings/media/cdns,csi2rx.yaml | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/media/cdns,csi2rx.yaml b/Documentation/devicetree/bindings/media/cdns,csi2rx.yaml
index 2008a47c0580..6ed9a5621064 100644
--- a/Documentation/devicetree/bindings/media/cdns,csi2rx.yaml
+++ b/Documentation/devicetree/bindings/media/cdns,csi2rx.yaml
@@ -24,6 +24,14 @@ properties:
   reg:
     maxItems: 1
 
+  interrupts:
+    maxItems: 2
+
+  interrupt-names:
+    items:
+      - const: error_irq
+      - const: irq
+
   clocks:
     items:
       - description: CSI2Rx system clock
-- 
2.34.1

[PATCH v6 2/2] media: cadence: csi2rx: Enable csi2rx_err_irq interrupt and add support for VIDIOC_LOG_STATUS

[Yemike Abhilash Chandra]

Enable the csi2rx_err_irq interrupt to record any errors during streaming
and also add support for VIDIOC_LOG_STATUS ioctl. This allows users to
retrieve detailed error information during streaming, including FIFO
overflow, packet errors, and ECC errors.

Signed-off-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
---
 drivers/media/platform/cadence/cdns-csi2rx.c | 131 +++++++++++++++++++
 1 file changed, 131 insertions(+)

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index cebcae196eec..7f1ce95cdc3f 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -57,6 +57,25 @@
 #define CSI2RX_LANES_MAX	4
 #define CSI2RX_STREAMS_MAX	4
 
+#define CSI2RX_ERROR_IRQS_REG			0x28
+#define CSI2RX_ERROR_IRQS_MASK_REG		0x2C
+
+#define CSI2RX_STREAM3_FIFO_OVERFLOW_IRQ	BIT(19)
+#define CSI2RX_STREAM2_FIFO_OVERFLOW_IRQ	BIT(18)
+#define CSI2RX_STREAM1_FIFO_OVERFLOW_IRQ	BIT(17)
+#define CSI2RX_STREAM0_FIFO_OVERFLOW_IRQ	BIT(16)
+#define CSI2RX_FRONT_TRUNC_HDR_IRQ		BIT(12)
+#define CSI2RX_PROT_TRUNCATED_PACKET_IRQ	BIT(11)
+#define CSI2RX_FRONT_LP_NO_PAYLOAD_IRQ		BIT(10)
+#define CSI2RX_SP_INVALID_RCVD_IRQ		BIT(9)
+#define CSI2RX_DATA_ID_IRQ			BIT(7)
+#define CSI2RX_HEADER_CORRECTED_ECC_IRQ	BIT(6)
+#define CSI2RX_HEADER_ECC_IRQ			BIT(5)
+#define CSI2RX_PAYLOAD_CRC_IRQ			BIT(4)
+
+#define CSI2RX_ECC_ERRORS		GENMASK(7, 4)
+#define CSI2RX_PACKET_ERRORS		GENMASK(12, 9)
+
 enum csi2rx_pads {
 	CSI2RX_PAD_SINK,
 	CSI2RX_PAD_SOURCE_STREAM0,
@@ -71,9 +90,32 @@ struct csi2rx_fmt {
 	u8				bpp;
 };
 
+struct csi2rx_event {
+	u32 mask;
+	const char *name;
+};
+
+static const struct csi2rx_event csi2rx_events[] = {
+	{ CSI2RX_STREAM3_FIFO_OVERFLOW_IRQ, "Overflow of the Stream 3 FIFO detected" },
+	{ CSI2RX_STREAM2_FIFO_OVERFLOW_IRQ, "Overflow of the Stream 2 FIFO detected" },
+	{ CSI2RX_STREAM1_FIFO_OVERFLOW_IRQ, "Overflow of the Stream 1 FIFO detected" },
+	{ CSI2RX_STREAM0_FIFO_OVERFLOW_IRQ, "Overflow of the Stream 0 FIFO detected" },
+	{ CSI2RX_FRONT_TRUNC_HDR_IRQ, "A truncated header [short or long] has been received" },
+	{ CSI2RX_PROT_TRUNCATED_PACKET_IRQ, "A truncated long packet has been received" },
+	{ CSI2RX_FRONT_LP_NO_PAYLOAD_IRQ, "A truncated long packet has been received. No payload" },
+	{ CSI2RX_SP_INVALID_RCVD_IRQ, "A reserved or invalid short packet has been received" },
+	{ CSI2RX_DATA_ID_IRQ, "Data ID error in the header packet" },
+	{ CSI2RX_HEADER_CORRECTED_ECC_IRQ, "ECC error detected and corrected" },
+	{ CSI2RX_HEADER_ECC_IRQ, "Unrecoverable ECC error" },
+	{ CSI2RX_PAYLOAD_CRC_IRQ, "CRC error" },
+};
+
+#define CSI2RX_NUM_EVENTS		ARRAY_SIZE(csi2rx_events)
+
 struct csi2rx_priv {
 	struct device			*dev;
 	unsigned int			count;
+	int				error_irq;
 
 	/*
 	 * Used to prevent race conditions between multiple,
@@ -95,6 +137,7 @@ struct csi2rx_priv {
 	u8				max_lanes;
 	u8				max_streams;
 	bool				has_internal_dphy;
+	u32				events[CSI2RX_NUM_EVENTS];
 
 	struct v4l2_subdev		subdev;
 	struct v4l2_async_notifier	notifier;
@@ -124,6 +167,54 @@ static const struct csi2rx_fmt formats[] = {
 	{ .code	= MEDIA_BUS_FMT_BGR888_1X24,  .bpp = 24, },
 };
 
+static void csi2rx_configure_error_irq_mask(void __iomem *base,
+					    struct csi2rx_priv *csi2rx)
+{
+	u32 error_irq_mask = 0;
+
+	error_irq_mask |= CSI2RX_ECC_ERRORS;
+	error_irq_mask |= CSI2RX_PACKET_ERRORS;
+
+	/*
+	 * Iterate through all source pads and check if they are linked
+	 * to an active remote pad. If an active remote pad is found,
+	 * calculate the corresponding bit position and set it in
+	 * mask, enabling the stream overflow error in the mask.
+	 */
+	for (int i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
+		struct media_pad *remote_pad;
+
+		remote_pad = media_pad_remote_pad_first(&csi2rx->pads[i]);
+		if (remote_pad) {
+			int pad = i - CSI2RX_PAD_SOURCE_STREAM0;
+			u32 bit_mask = CSI2RX_STREAM0_FIFO_OVERFLOW_IRQ << pad;
+
+			error_irq_mask |= bit_mask;
+		}
+	}
+
+	writel(error_irq_mask, base + CSI2RX_ERROR_IRQS_MASK_REG);
+}
+
+static irqreturn_t csi2rx_irq_handler(int irq, void *dev_id)
+{
+	struct csi2rx_priv *csi2rx = dev_id;
+	int i;
+	u32 error_status, error_mask;
+
+	error_status = readl(csi2rx->base + CSI2RX_ERROR_IRQS_REG);
+	error_mask = readl(csi2rx->base + CSI2RX_ERROR_IRQS_MASK_REG);
+
+	for (i = 0; i < CSI2RX_NUM_EVENTS; i++)
+		if ((error_status & csi2rx_events[i].mask) &&
+		    (error_mask & csi2rx_events[i].mask))
+			csi2rx->events[i]++;
+
+	writel(error_status, csi2rx->base + CSI2RX_ERROR_IRQS_REG);
+
+	return IRQ_HANDLED;
+}
+
 static const struct csi2rx_fmt *csi2rx_get_fmt_by_code(u32 code)
 {
 	unsigned int i;
@@ -220,6 +311,9 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
 	reset_control_deassert(csi2rx->p_rst);
 	csi2rx_reset(csi2rx);
 
+	if (csi2rx->error_irq >= 0)
+		csi2rx_configure_error_irq_mask(csi2rx->base, csi2rx);
+
 	reg = csi2rx->num_lanes << 8;
 	for (i = 0; i < csi2rx->num_lanes; i++) {
 		reg |= CSI2RX_STATIC_CFG_DLANE_MAP(i, csi2rx->lanes[i]);
@@ -332,6 +426,8 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)
 	reset_control_assert(csi2rx->sys_rst);
 	clk_disable_unprepare(csi2rx->sys_clk);
 
+	writel(0, csi2rx->base + CSI2RX_ERROR_IRQS_MASK_REG);
+
 	for (i = 0; i < csi2rx->max_streams; i++) {
 		writel(CSI2RX_STREAM_CTRL_STOP,
 		       csi2rx->base + CSI2RX_STREAM_CTRL_REG(i));
@@ -363,6 +459,21 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)
 	}
 }
 
+static int csi2rx_log_status(struct v4l2_subdev *sd)
+{
+	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(sd);
+	unsigned int i;
+
+	for (i = 0; i < CSI2RX_NUM_EVENTS; i++) {
+		if (csi2rx->events[i])
+			dev_info(csi2rx->dev, "%s events: %d\n",
+				 csi2rx_events[i].name,
+				 csi2rx->events[i]);
+	}
+
+	return 0;
+}
+
 static int csi2rx_s_stream(struct v4l2_subdev *subdev, int enable)
 {
 	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
@@ -468,7 +579,12 @@ static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
 	.s_stream	= csi2rx_s_stream,
 };
 
+static const struct v4l2_subdev_core_ops csi2rx_core_ops = {
+	.log_status	= csi2rx_log_status,
+};
+
 static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
+	.core		= &csi2rx_core_ops,
 	.video		= &csi2rx_video_ops,
 	.pad		= &csi2rx_pad_ops,
 };
@@ -705,6 +821,21 @@ static int csi2rx_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_cleanup;
 
+	csi2rx->error_irq = platform_get_irq_byname_optional(pdev, "error_irq");
+
+	if (csi2rx->error_irq < 0) {
+		dev_dbg(csi2rx->dev, "Optional interrupt not defined, proceeding without it\n");
+	} else {
+		ret = devm_request_irq(csi2rx->dev, csi2rx->error_irq,
+				       csi2rx_irq_handler, 0,
+				       dev_name(&pdev->dev), csi2rx);
+		if (ret) {
+			dev_err(csi2rx->dev,
+				"Unable to request interrupt: %d\n", ret);
+			goto err_cleanup;
+		}
+	}
+
 	ret = v4l2_subdev_init_finalize(&csi2rx->subdev);
 	if (ret)
 		goto err_cleanup;
-- 
2.34.1

Re: [PATCH v6 2/2] media: cadence: csi2rx: Enable csi2rx_err_irq interrupt and add support for VIDIOC_LOG_STATUS

[Jai Luthra]

[-- Attachment #1: Type: text/plain, Size: 648 bytes --]

Hi Abhilash,

Thanks for the patch.

On Wed, Apr 16, 2025 at 05:49:38PM +0530, Yemike Abhilash Chandra wrote:
> Enable the csi2rx_err_irq interrupt to record any errors during streaming
> and also add support for VIDIOC_LOG_STATUS ioctl. This allows users to
> retrieve detailed error information during streaming, including FIFO
> overflow, packet errors, and ECC errors.
> 
> Signed-off-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>

Tested-by: Jai Luthra <jai.luthra@linux.dev>

> ---
>  drivers/media/platform/cadence/cdns-csi2rx.c | 131 +++++++++++++++++++
>  1 file changed, 131 insertions(+)
> 
[snip]

--
Jai

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

[PATCH v6 2/2] media: cadence: csi2rx: Enable csi2rx_err_irq interrupt and add support for VIDIOC_LOG_STATUS

[Changhuang Liang]

> Enable the csi2rx_err_irq interrupt to record any errors during streaming
> and also add support for VIDIOC_LOG_STATUS ioctl. This allows users to
> retrieve detailed error information during streaming, including FIFO
> overflow, packet errors, and ECC errors.
>
> Signed-off-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>

Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>

> ---
>  drivers/media/platform/cadence/cdns-csi2rx.c | 131 +++++++++++++++++++
>  1 file changed, 131 insertions(+)