[PATCH v4 0/6] media: ti, cdns: Multiple pixel support and misc fixes

[PATCH v4 0/6] media: ti, cdns: Multiple pixel support and misc fixes

[Jai Luthra]

Hi,

The first four patches in this series are miscellaneous fixes and
improvements in the Cadence and TI CSI-RX drivers around probing, fwnode
and link creation.

The last two patches add support for transmitting multiple pixels per
clock on the internal bus between Cadence CSI-RX bridge and TI CSI-RX
wrapper. As this internal bus is 32-bit wide, the maximum number of
pixels that can be transmitted per cycle depend upon the format's bit
width. Secondly, the downstream element must support unpacking of
multiple pixels.

Thus we export a module function that can be used by the downstream
driver to negotiate the pixels per cycle on the output pixel stream of
the Cadence bridge.

Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
---
Changes in v4:
- Rebase on top of v6.17-rc1
- Add missing include for linux/export.h in cdns-csi2rx.c
- Link to v3: https://lore.kernel.org/r/20250626-probe_fixes-v3-0-83e735ae466e@ideasonboard.com

Changes in v3:
- Move cdns-csi2rx header to include/media
- Export symbol from cdns-csi2rx.c to be used only through
  the j721e-csi2rx.c module namespace
- Other minor fixes suggested by Sakari
- Add Abhilash's T-by tags
- Link to v2: https://lore.kernel.org/r/20250410-probe_fixes-v2-0-801bc6eebdea@ideasonboard.com

Changes in v2:
- Rebase on v6.15-rc1
- Fix lkp warnings in PATCH 5/6 missing header for FIELD_PREP
- Add R-By tags from Devarsh and Changhuang
- Link to v1: https://lore.kernel.org/r/20250324-probe_fixes-v1-0-5cd5b9e1cfac@ideasonboard.com

---
Jai Luthra (6):
      media: ti: j721e-csi2rx: Use devm_of_platform_populate
      media: ti: j721e-csi2rx: Use fwnode_get_named_child_node
      media: ti: j721e-csi2rx: Fix source subdev link creation
      media: cadence: csi2rx: Implement get_fwnode_pad op
      media: cadence: cdns-csi2rx: Support multiple pixels per clock cycle
      media: ti: j721e-csi2rx: Support multiple pixels per clock

 MAINTAINERS                                        |  1 +
 drivers/media/platform/cadence/cdns-csi2rx.c       | 75 ++++++++++++++++------
 drivers/media/platform/ti/Kconfig                  |  3 +-
 .../media/platform/ti/j721e-csi2rx/j721e-csi2rx.c  | 65 ++++++++++++++-----
 include/media/cadence/cdns-csi2rx.h                | 19 ++++++
 5 files changed, 128 insertions(+), 35 deletions(-)
---
base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
change-id: 20250314-probe_fixes-7e0ec33c7fee

Best regards,
-- 
Jai Luthra <jai.luthra@ideasonboard.com>

[PATCH v4 1/6] media: ti: j721e-csi2rx: Use devm_of_platform_populate

[Jai Luthra]

Ensure that we clean up the platform bus when we remove this driver.

This fixes a crash seen when reloading the module for the child device
with the parent not yet reloaded.

Fixes: b4a3d877dc92 ("media: ti: Add CSI2RX support for J721E")
Cc: stable@vger.kernel.org
Reviewed-by: Devarsh Thakkar <devarsht@ti.com>
Tested-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com> (on SK-AM68)
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
---
 drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index b628d6e081dbcb4dae06a236455228c168945660..6d4cccbe1fdea11f6aefd63a985a9a3c16a7a9fe 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -1120,7 +1120,7 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_vb2q;
 
-	ret = of_platform_populate(csi->dev->of_node, NULL, NULL, csi->dev);
+	ret = devm_of_platform_populate(csi->dev);
 	if (ret) {
 		dev_err(csi->dev, "Failed to create children: %d\n", ret);
 		goto err_subdev;

-- 
2.50.1

[PATCH v4 2/6] media: ti: j721e-csi2rx: Use fwnode_get_named_child_node

[Jai Luthra]

Simplify notifier registration logic. Instead of first getting the
device node, get the fwnode of the child directly.

Reviewed-by: Devarsh Thakkar <devarsht@ti.com>
Tested-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com> (on SK-AM68)
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
---
 drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 6d4cccbe1fdea11f6aefd63a985a9a3c16a7a9fe..daadb870514602bd59519d6cd2966a9ff56794fe 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 
 #include <media/mipi-csi2.h>
 #include <media/v4l2-device.h>
@@ -450,25 +451,23 @@ static int ti_csi2rx_notifier_register(struct ti_csi2rx_dev *csi)
 {
 	struct fwnode_handle *fwnode;
 	struct v4l2_async_connection *asc;
-	struct device_node *node;
 	int ret;
 
-	node = of_get_child_by_name(csi->dev->of_node, "csi-bridge");
-	if (!node)
+	fwnode = fwnode_get_named_child_node(csi->dev->fwnode, "csi-bridge");
+	if (!fwnode)
 		return -EINVAL;
 
-	fwnode = of_fwnode_handle(node);
-	if (!fwnode) {
-		of_node_put(node);
-		return -EINVAL;
-	}
-
 	v4l2_async_nf_init(&csi->notifier, &csi->v4l2_dev);
 	csi->notifier.ops = &csi_async_notifier_ops;
 
 	asc = v4l2_async_nf_add_fwnode(&csi->notifier, fwnode,
 				       struct v4l2_async_connection);
-	of_node_put(node);
+	/*
+	 * Calling v4l2_async_nf_add_fwnode grabs a refcount,
+	 * so drop the one we got in fwnode_get_named_child_node
+	 */
+	fwnode_handle_put(fwnode);
+
 	if (IS_ERR(asc)) {
 		v4l2_async_nf_cleanup(&csi->notifier);
 		return PTR_ERR(asc);

-- 
2.50.1

[PATCH v4 3/6] media: ti: j721e-csi2rx: Fix source subdev link creation

[Jai Luthra]

We don't use OF ports and remote-endpoints to connect the CSI2RX bridge
and this device in the device tree, thus it is wrong to use
v4l2_create_fwnode_links_to_pad() to create the media graph link between
the two.

It works out on accident, as neither the source nor the sink implement
the .get_fwnode_pad() callback, and the framework helper falls back on
using the first source and sink pads to create the link between them.

Instead, manually create the media link from the first source pad of the
bridge to the first sink pad of the J721E CSI2RX.

Fixes: b4a3d877dc92 ("media: ti: Add CSI2RX support for J721E")
Cc: stable@vger.kernel.org
Reviewed-by: Devarsh Thakkar <devarsht@ti.com>
Tested-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com> (on SK-AM68)
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
---
 drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index daadb870514602bd59519d6cd2966a9ff56794fe..09e5618de7dd0cdd5bf42083804ff7ca53f0973b 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -53,6 +53,8 @@
 #define DRAIN_TIMEOUT_MS		50
 #define DRAIN_BUFFER_SIZE		SZ_32K
 
+#define CSI2RX_BRIDGE_SOURCE_PAD	1
+
 struct ti_csi2rx_fmt {
 	u32				fourcc;	/* Four character code. */
 	u32				code;	/* Mbus code. */
@@ -427,8 +429,9 @@ static int csi_async_notifier_complete(struct v4l2_async_notifier *notifier)
 	if (ret)
 		return ret;
 
-	ret = v4l2_create_fwnode_links_to_pad(csi->source, &csi->pad,
-					      MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
+	ret = media_create_pad_link(&csi->source->entity, CSI2RX_BRIDGE_SOURCE_PAD,
+				    &vdev->entity, csi->pad.index,
+				    MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
 
 	if (ret) {
 		video_unregister_device(vdev);

-- 
2.50.1

[PATCH v4 4/6] media: cadence: csi2rx: Implement get_fwnode_pad op

[Jai Luthra]

Use v4l2_subdev_get_fwnode_pad_1_to_1() as the get_fwnode_pad operation.
Cadence CSI2RX maps port numbers and pad indices 1:1.

Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
Reviewed-by: Devarsh Thakkar <devarsht@ti.com>
Tested-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com> (on SK-AM68)
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
---
 drivers/media/platform/cadence/cdns-csi2rx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 7f1ce95cdc3f13e29b3892cff89f21ee0d71a168..c232047487852d431957434c4c97f84dbb66acad 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -595,6 +595,7 @@ static const struct v4l2_subdev_internal_ops csi2rx_internal_ops = {
 
 static const struct media_entity_operations csi2rx_media_ops = {
 	.link_validate = v4l2_subdev_link_validate,
+	.get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
 };
 
 static int csi2rx_async_bound(struct v4l2_async_notifier *notifier,

-- 
2.50.1

[PATCH v4 5/6] media: cadence: cdns-csi2rx: Support multiple pixels per clock cycle

[Jai Luthra]

The output pixel interface is a parallel bus (32 bits), which
supports sending multiple pixels (1, 2 or 4) per clock cycle for
smaller pixel widths like RAW8-RAW16.

Dual-pixel and Quad-pixel modes can be a requirement if the export rate
of the Cadence IP in Single-pixel mode maxes out before the maximum
supported DPHY-RX frequency, which is the case with TI's integration of
this IP [1].

So, we export a function that lets the downstream hardware block request
a higher pixel-per-clock on a particular output pad.

We check if we can support the requested pixels per clock given the
known maximum for the currently configured format. If not, we set it
to the highest feasible value and return this value to the caller.

[1] Section 12.6.1.4.8.14 CSI_RX_IF Programming Restrictions of AM62 TRM

Link: https://www.ti.com/lit/pdf/spruj16
Tested-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com> (on SK-AM68)
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
---
Changes in v3:
- Move cdns-csi2rx header to include/media/cadence and update
  MAINTAINERS file
- Export symbol from cdns-csi2rx.c to be used only through the
  j721e-csi2rx.c module namespace
- Other minor fixes suggested by Sakari
---
 MAINTAINERS                                  |  1 +
 drivers/media/platform/cadence/cdns-csi2rx.c | 74 +++++++++++++++++++++-------
 include/media/cadence/cdns-csi2rx.h          | 19 +++++++
 3 files changed, 76 insertions(+), 18 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index fe168477caa45799dfe07de2f54de6d6a1ce0615..eca3bb8b35926db5114d92c50bb59b90b6ad2d90 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5354,6 +5354,7 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/media/cdns,*.txt
 F:	Documentation/devicetree/bindings/media/cdns,csi2rx.yaml
 F:	drivers/media/platform/cadence/cdns-csi2*
+F:	include/media/cadence/cdns-csi2*
 
 CADENCE NAND DRIVER
 L:	linux-mtd@lists.infradead.org
diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index c232047487852d431957434c4c97f84dbb66acad..828b4ba4301d3e96c73f7695a7e254ae5f681060 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -5,8 +5,10 @@
  * Copyright (C) 2017 Cadence Design Systems Inc.
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/export.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
@@ -17,6 +19,7 @@
 #include <linux/reset.h>
 #include <linux/slab.h>
 
+#include <media/cadence/cdns-csi2rx.h>
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-fwnode.h>
@@ -52,7 +55,9 @@
 #define CSI2RX_STREAM_DATA_CFG_VC_SELECT(n)		BIT((n) + 16)
 
 #define CSI2RX_STREAM_CFG_REG(n)		(CSI2RX_STREAM_BASE(n) + 0x00c)
-#define CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF		(1 << 8)
+#define CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF		BIT(8)
+#define CSI2RX_STREAM_CFG_NUM_PIXELS_MASK		GENMASK(5, 4)
+#define CSI2RX_STREAM_CFG_NUM_PIXELS(n)			((n) >> 1U)
 
 #define CSI2RX_LANES_MAX	4
 #define CSI2RX_STREAMS_MAX	4
@@ -87,7 +92,10 @@ enum csi2rx_pads {
 
 struct csi2rx_fmt {
 	u32				code;
+	/* width of a single pixel on CSI-2 bus */
 	u8				bpp;
+	/* max pixels per clock supported on output bus */
+	u8				max_pixels;
 };
 
 struct csi2rx_event {
@@ -132,6 +140,7 @@ struct csi2rx_priv {
 	struct reset_control		*pixel_rst[CSI2RX_STREAMS_MAX];
 	struct phy			*dphy;
 
+	u8				num_pixels[CSI2RX_STREAMS_MAX];
 	u8				lanes[CSI2RX_LANES_MAX];
 	u8				num_lanes;
 	u8				max_lanes;
@@ -149,22 +158,22 @@ struct csi2rx_priv {
 };
 
 static const struct csi2rx_fmt formats[] = {
-	{ .code	= MEDIA_BUS_FMT_YUYV8_1X16, .bpp = 16, },
-	{ .code	= MEDIA_BUS_FMT_UYVY8_1X16, .bpp = 16, },
-	{ .code	= MEDIA_BUS_FMT_YVYU8_1X16, .bpp = 16, },
-	{ .code	= MEDIA_BUS_FMT_VYUY8_1X16, .bpp = 16, },
-	{ .code	= MEDIA_BUS_FMT_SBGGR8_1X8, .bpp = 8, },
-	{ .code	= MEDIA_BUS_FMT_SGBRG8_1X8, .bpp = 8, },
-	{ .code	= MEDIA_BUS_FMT_SGRBG8_1X8, .bpp = 8, },
-	{ .code	= MEDIA_BUS_FMT_SRGGB8_1X8, .bpp = 8, },
-	{ .code	= MEDIA_BUS_FMT_Y8_1X8,     .bpp = 8, },
-	{ .code	= MEDIA_BUS_FMT_SBGGR10_1X10, .bpp = 10, },
-	{ .code	= MEDIA_BUS_FMT_SGBRG10_1X10, .bpp = 10, },
-	{ .code	= MEDIA_BUS_FMT_SGRBG10_1X10, .bpp = 10, },
-	{ .code	= MEDIA_BUS_FMT_SRGGB10_1X10, .bpp = 10, },
-	{ .code	= MEDIA_BUS_FMT_RGB565_1X16,  .bpp = 16, },
-	{ .code	= MEDIA_BUS_FMT_RGB888_1X24,  .bpp = 24, },
-	{ .code	= MEDIA_BUS_FMT_BGR888_1X24,  .bpp = 24, },
+	{ .code	= MEDIA_BUS_FMT_YUYV8_1X16, .bpp = 16, .max_pixels = 2, },
+	{ .code	= MEDIA_BUS_FMT_UYVY8_1X16, .bpp = 16, .max_pixels = 2, },
+	{ .code	= MEDIA_BUS_FMT_YVYU8_1X16, .bpp = 16, .max_pixels = 2, },
+	{ .code	= MEDIA_BUS_FMT_VYUY8_1X16, .bpp = 16, .max_pixels = 2, },
+	{ .code	= MEDIA_BUS_FMT_SBGGR8_1X8, .bpp = 8, .max_pixels = 4, },
+	{ .code	= MEDIA_BUS_FMT_SGBRG8_1X8, .bpp = 8, .max_pixels = 4, },
+	{ .code	= MEDIA_BUS_FMT_SGRBG8_1X8, .bpp = 8, .max_pixels = 4, },
+	{ .code	= MEDIA_BUS_FMT_SRGGB8_1X8, .bpp = 8, .max_pixels = 4, },
+	{ .code	= MEDIA_BUS_FMT_Y8_1X8,     .bpp = 8, .max_pixels = 4, },
+	{ .code	= MEDIA_BUS_FMT_SBGGR10_1X10, .bpp = 10, .max_pixels = 2, },
+	{ .code	= MEDIA_BUS_FMT_SGBRG10_1X10, .bpp = 10, .max_pixels = 2, },
+	{ .code	= MEDIA_BUS_FMT_SGRBG10_1X10, .bpp = 10, .max_pixels = 2, },
+	{ .code	= MEDIA_BUS_FMT_SRGGB10_1X10, .bpp = 10, .max_pixels = 2, },
+	{ .code	= MEDIA_BUS_FMT_RGB565_1X16,  .bpp = 16, .max_pixels = 1, },
+	{ .code	= MEDIA_BUS_FMT_RGB888_1X24,  .bpp = 24, .max_pixels = 1, },
+	{ .code	= MEDIA_BUS_FMT_BGR888_1X24,  .bpp = 24, .max_pixels = 1, },
 };
 
 static void csi2rx_configure_error_irq_mask(void __iomem *base,
@@ -370,7 +379,9 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
 
 		reset_control_deassert(csi2rx->pixel_rst[i]);
 
-		writel(CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF,
+		writel(CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF |
+			       FIELD_PREP(CSI2RX_STREAM_CFG_NUM_PIXELS_MASK,
+					  csi2rx->num_pixels[i]),
 		       csi2rx->base + CSI2RX_STREAM_CFG_REG(i));
 
 		/*
@@ -569,6 +580,33 @@ static int csi2rx_init_state(struct v4l2_subdev *subdev,
 	return csi2rx_set_fmt(subdev, state, &format);
 }
 
+int cdns_csi2rx_negotiate_ppc(struct v4l2_subdev *subdev, unsigned int pad,
+			      u8 *ppc)
+{
+	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
+	const struct csi2rx_fmt *csi_fmt;
+	struct v4l2_subdev_state *state;
+	struct v4l2_mbus_framefmt *fmt;
+
+	if (!ppc || pad < CSI2RX_PAD_SOURCE_STREAM0 || pad >= CSI2RX_PAD_MAX)
+		return -EINVAL;
+
+	state = v4l2_subdev_lock_and_get_active_state(subdev);
+	fmt = v4l2_subdev_state_get_format(state, pad);
+	csi_fmt = csi2rx_get_fmt_by_code(fmt->code);
+
+	/* Reduce requested PPC if it is too high */
+	*ppc = min(*ppc, csi_fmt->max_pixels);
+
+	v4l2_subdev_unlock_state(state);
+
+	csi2rx->num_pixels[pad - CSI2RX_PAD_SOURCE_STREAM0] =
+		CSI2RX_STREAM_CFG_NUM_PIXELS(*ppc);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL_FOR_MODULES(cdns_csi2rx_negotiate_ppc, "j721e-csi2rx");
+
 static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
 	.enum_mbus_code	= csi2rx_enum_mbus_code,
 	.get_fmt	= v4l2_subdev_get_fmt,
diff --git a/include/media/cadence/cdns-csi2rx.h b/include/media/cadence/cdns-csi2rx.h
new file mode 100644
index 0000000000000000000000000000000000000000..782d03fc36d1fc06fddab04c4f8081af62c3766f
--- /dev/null
+++ b/include/media/cadence/cdns-csi2rx.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef _CDNS_CSI2RX_H
+#define _CDNS_CSI2RX_H
+
+#include <media/v4l2-subdev.h>
+
+/**
+ * cdns_csi2rx_negotiate_ppc - Negotiate pixel-per-clock on output interface
+ *
+ * @subdev: point to &struct v4l2_subdev
+ * @pad: pad number of the source pad
+ * @ppc: pointer to requested pixel-per-clock value
+ *
+ * Returns 0 on success, negative error code otherwise.
+ */
+int cdns_csi2rx_negotiate_ppc(struct v4l2_subdev *subdev, unsigned int pad,
+			      u8 *ppc);
+
+#endif

-- 
2.50.1

[PATCH v4 6/6] media: ti: j721e-csi2rx: Support multiple pixels per clock

[Jai Luthra]

Add support for negotiating the highest possible pixel mode (from
single, dual, quad) with the Cadence CSI2RX bridge. This is required to
drain the Cadence stream FIFOs without overflowing when the source is
operating at a high link-frequency [1].

Also, update the Kconfig as this introduces a hard build-time dependency
on the Cadence CSI2RX driver, even for a COMPILE_TEST.

[1] Section 12.6.1.4.8.14 CSI_RX_IF Programming Restrictions of AM62 TRM

Link: https://www.ti.com/lit/pdf/spruj16
Tested-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com> (on SK-AM68)
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
---
Changes in v3:
- Reorder declarations in ti_csi2rx_request_max_ppc to be reverse
  christmas tree
- Include cdns-csi2rx.h from its new location at include/media/cadence
---
 drivers/media/platform/ti/Kconfig                  |  3 +-
 .../media/platform/ti/j721e-csi2rx/j721e-csi2rx.c  | 37 ++++++++++++++++++++--
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/drivers/media/platform/ti/Kconfig b/drivers/media/platform/ti/Kconfig
index bab998c4179aca3b07372782b9be7de340cb8d45..3bc4aa35887e6edc9fa8749d9956a67714c59001 100644
--- a/drivers/media/platform/ti/Kconfig
+++ b/drivers/media/platform/ti/Kconfig
@@ -67,7 +67,8 @@ config VIDEO_TI_J721E_CSI2RX
 	tristate "TI J721E CSI2RX wrapper layer driver"
 	depends on VIDEO_DEV && VIDEO_V4L2_SUBDEV_API
 	depends on MEDIA_SUPPORT && MEDIA_CONTROLLER
-	depends on (PHY_CADENCE_DPHY_RX && VIDEO_CADENCE_CSI2RX) || COMPILE_TEST
+	depends on VIDEO_CADENCE_CSI2RX
+	depends on PHY_CADENCE_DPHY_RX || COMPILE_TEST
 	depends on ARCH_K3 || COMPILE_TEST
 	select VIDEOBUF2_DMA_CONTIG
 	select V4L2_FWNODE
diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 09e5618de7dd0cdd5bf42083804ff7ca53f0973b..b5980778183944217a03d23075a0bcef4c424f90 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -15,6 +15,7 @@
 #include <linux/platform_device.h>
 #include <linux/property.h>
 
+#include <media/cadence/cdns-csi2rx.h>
 #include <media/mipi-csi2.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-ioctl.h>
@@ -29,6 +30,7 @@
 #define SHIM_DMACNTX			0x20
 #define SHIM_DMACNTX_EN			BIT(31)
 #define SHIM_DMACNTX_YUV422		GENMASK(27, 26)
+#define SHIM_DMACNTX_DUAL_PCK_CFG	BIT(24)
 #define SHIM_DMACNTX_SIZE		GENMASK(21, 20)
 #define SHIM_DMACNTX_FMT		GENMASK(5, 0)
 #define SHIM_DMACNTX_YUV422_MODE_11	3
@@ -40,6 +42,7 @@
 #define SHIM_PSI_CFG0_SRC_TAG		GENMASK(15, 0)
 #define SHIM_PSI_CFG0_DST_TAG		GENMASK(31, 16)
 
+#define TI_CSI2RX_MAX_PIX_PER_CLK	4
 #define PSIL_WORD_SIZE_BYTES		16
 /*
  * There are no hard limits on the width or height. The DMA engine can handle
@@ -110,6 +113,7 @@ struct ti_csi2rx_dev {
 	struct v4l2_format		v_fmt;
 	struct ti_csi2rx_dma		dma;
 	u32				sequence;
+	u8				pix_per_clk;
 };
 
 static const struct ti_csi2rx_fmt ti_csi2rx_formats[] = {
@@ -485,6 +489,26 @@ static int ti_csi2rx_notifier_register(struct ti_csi2rx_dev *csi)
 	return 0;
 }
 
+/* Request maximum possible pixels per clock from the bridge */
+static void ti_csi2rx_request_max_ppc(struct ti_csi2rx_dev *csi)
+{
+	u8 ppc = TI_CSI2RX_MAX_PIX_PER_CLK;
+	struct media_pad *pad;
+	int ret;
+
+	pad = media_entity_remote_source_pad_unique(&csi->vdev.entity);
+	if (!pad)
+		return;
+
+	ret = cdns_csi2rx_negotiate_ppc(csi->source, pad->index, &ppc);
+	if (ret) {
+		dev_warn(csi->dev, "NUM_PIXELS negotiation failed: %d\n", ret);
+		csi->pix_per_clk = 1;
+	} else {
+		csi->pix_per_clk = ppc;
+	}
+}
+
 static void ti_csi2rx_setup_shim(struct ti_csi2rx_dev *csi)
 {
 	const struct ti_csi2rx_fmt *fmt;
@@ -496,6 +520,9 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_dev *csi)
 	reg = SHIM_CNTL_PIX_RST;
 	writel(reg, csi->shim + SHIM_CNTL);
 
+	/* Negotiate pixel count from the source */
+	ti_csi2rx_request_max_ppc(csi);
+
 	reg = SHIM_DMACNTX_EN;
 	reg |= FIELD_PREP(SHIM_DMACNTX_FMT, fmt->csi_dt);
 
@@ -524,14 +551,18 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_dev *csi)
 	case V4L2_PIX_FMT_YVYU:
 		reg |= FIELD_PREP(SHIM_DMACNTX_YUV422,
 				  SHIM_DMACNTX_YUV422_MODE_11);
+		/* Multiple pixels are handled differently for packed YUV */
+		if (csi->pix_per_clk == 2)
+			reg |= SHIM_DMACNTX_DUAL_PCK_CFG;
+		reg |= FIELD_PREP(SHIM_DMACNTX_SIZE, fmt->size);
 		break;
 	default:
-		/* Ignore if not YUV 4:2:2 */
+		/* By default we change the shift size for multiple pixels */
+		reg |= FIELD_PREP(SHIM_DMACNTX_SIZE,
+				  fmt->size + (csi->pix_per_clk >> 1));
 		break;
 	}
 
-	reg |= FIELD_PREP(SHIM_DMACNTX_SIZE, fmt->size);
-
 	writel(reg, csi->shim + SHIM_DMACNTX);
 
 	reg = FIELD_PREP(SHIM_PSI_CFG0_SRC_TAG, 0) |

-- 
2.50.1

Re: [PATCH v4 0/6] media: ti, cdns: Multiple pixel support and misc fixes

[Rishikesh Donadkar]

On 11/08/25 13:50, Jai Luthra wrote:
> Hi,


Hi Jai,
Thank you for the patches !


>
> The first four patches in this series are miscellaneous fixes and
> improvements in the Cadence and TI CSI-RX drivers around probing, fwnode
> and link creation.
>
> The last two patches add support for transmitting multiple pixels per
> clock on the internal bus between Cadence CSI-RX bridge and TI CSI-RX
> wrapper. As this internal bus is 32-bit wide, the maximum number of
> pixels that can be transmitted per cycle depend upon the format's bit
> width. Secondly, the downstream element must support unpacking of
> multiple pixels.
>
> Thus we export a module function that can be used by the downstream
> driver to negotiate the pixels per cycle on the output pixel stream of
> the Cadence bridge.
>
> Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>


For the entire series,

Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>

Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>


Test Logs (SK-AM62A + IMX219) :

https://gist.github.com/Rishikesh-D/cb1d06cf341c2327da0d38a6b21688d6


Regards,

Rishikesh

> ---
> Changes in v4:
> - Rebase on top of v6.17-rc1
> - Add missing include for linux/export.h in cdns-csi2rx.c
> - Link to v3: https://lore.kernel.org/r/20250626-probe_fixes-v3-0-83e735ae466e@ideasonboard.com
>
> Changes in v3:
> - Move cdns-csi2rx header to include/media
> - Export symbol from cdns-csi2rx.c to be used only through
>    the j721e-csi2rx.c module namespace
> - Other minor fixes suggested by Sakari
> - Add Abhilash's T-by tags
> - Link to v2: https://lore.kernel.org/r/20250410-probe_fixes-v2-0-801bc6eebdea@ideasonboard.com
>
> Changes in v2:
> - Rebase on v6.15-rc1
> - Fix lkp warnings in PATCH 5/6 missing header for FIELD_PREP
> - Add R-By tags from Devarsh and Changhuang
> - Link to v1: https://lore.kernel.org/r/20250324-probe_fixes-v1-0-5cd5b9e1cfac@ideasonboard.com
>
> ---
> Jai Luthra (6):
>        media: ti: j721e-csi2rx: Use devm_of_platform_populate
>        media: ti: j721e-csi2rx: Use fwnode_get_named_child_node
>        media: ti: j721e-csi2rx: Fix source subdev link creation
>        media: cadence: csi2rx: Implement get_fwnode_pad op
>        media: cadence: cdns-csi2rx: Support multiple pixels per clock cycle
>        media: ti: j721e-csi2rx: Support multiple pixels per clock
>
>   MAINTAINERS                                        |  1 +
>   drivers/media/platform/cadence/cdns-csi2rx.c       | 75 ++++++++++++++++------
>   drivers/media/platform/ti/Kconfig                  |  3 +-
>   .../media/platform/ti/j721e-csi2rx/j721e-csi2rx.c  | 65 ++++++++++++++-----
>   include/media/cadence/cdns-csi2rx.h                | 19 ++++++
>   5 files changed, 128 insertions(+), 35 deletions(-)
> ---
> base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
> change-id: 20250314-probe_fixes-7e0ec33c7fee
>
> Best regards,