Re: [PATCH 26/39] drm/bridge: imx: Add NXP i.MX95 pixel interleaver support

[Frank Li <Frank.li@nxp.com>]

On Sat, Oct 11, 2025 at 06:51:41PM +0200, Marek Vasut wrote:
> From: Liu Ying <victor.liu@nxp.com>
>
> Add NXP i.MX95 pixel interleaver support.
>
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> Signed-off-by: Marek Vasut <marek.vasut@mailbox.org>
> ---
> Cc: Abel Vesa <abelvesa@kernel.org>
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Fabio Estevam <festevam@gmail.com>
> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
> Cc: Liu Ying <victor.liu@nxp.com>
> Cc: Lucas Stach <l.stach@pengutronix.de>
> Cc: Peng Fan <peng.fan@nxp.com>
> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Shawn Guo <shawnguo@kernel.org>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: devicetree@vger.kernel.org
> Cc: dri-devel@lists.freedesktop.org
> Cc: imx@lists.linux.dev
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-clk@vger.kernel.org
> ---
>  drivers/gpu/drm/bridge/imx/Kconfig            |   9 +
>  drivers/gpu/drm/bridge/imx/Makefile           |   1 +
>  .../drm/bridge/imx/imx95-pixel-interleaver.c  | 217 ++++++++++++++++++
>  3 files changed, 227 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/imx/imx95-pixel-interleaver.c
>
> diff --git a/drivers/gpu/drm/bridge/imx/Kconfig b/drivers/gpu/drm/bridge/imx/Kconfig
> index 9a480c6abb856..3e1b1d825d7bf 100644
> --- a/drivers/gpu/drm/bridge/imx/Kconfig
> +++ b/drivers/gpu/drm/bridge/imx/Kconfig
> @@ -88,4 +88,13 @@ config DRM_IMX93_MIPI_DSI
>  	  Choose this to enable MIPI DSI controller found in Freescale i.MX93
>  	  processor.
>
> +config DRM_IMX95_PIXEL_INTERLEAVER
> +	tristate "NXP i.MX95 pixel interleaver"
> +	depends on OF && MFD_SYSCON && COMMON_CLK
> +	select DRM_KMS_HELPER
> +	select REGMAP_MMIO
> +	help
> +	  Choose this to enable pixel interleaver found in NXP i.MX95
> +	  processors.
> +
>  endif # ARCH_MXC || COMPILE_TEST
> diff --git a/drivers/gpu/drm/bridge/imx/Makefile b/drivers/gpu/drm/bridge/imx/Makefile
> index dd5d485848066..583054c70f002 100644
> --- a/drivers/gpu/drm/bridge/imx/Makefile
> +++ b/drivers/gpu/drm/bridge/imx/Makefile
> @@ -8,3 +8,4 @@ obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-combiner.o
>  obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK) += imx8qxp-pixel-link.o
>  obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK_TO_DPI) += imx8qxp-pxl2dpi.o
>  obj-$(CONFIG_DRM_IMX93_MIPI_DSI) += imx93-mipi-dsi.o
> +obj-$(CONFIG_DRM_IMX95_PIXEL_INTERLEAVER) += imx95-pixel-interleaver.o
> diff --git a/drivers/gpu/drm/bridge/imx/imx95-pixel-interleaver.c b/drivers/gpu/drm/bridge/imx/imx95-pixel-interleaver.c
> new file mode 100644
> index 0000000000000..e6d96e68db895
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/imx/imx95-pixel-interleaver.c
> @@ -0,0 +1,217 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +/*
> + * Copyright 2023 NXP

2025?

> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/bits.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/media-bus-format.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_graph.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#include <drm/drm_atomic_state_helper.h>
> +#include <drm/drm_bridge.h>
> +
> +#define PIXEL_INTERLEAVER_CTRL	0x4
> +#define  DISP_IN_SEL		BIT(1)
> +#define  MODE			BIT(0)
> +
> +#define CTRL			0x0
> +#define  VSYNC_POLARITY		BIT(10)
> +#define  HSYNC_POLARITY		BIT(9)
> +
> +#define SWRST			0x20
> +#define  SW_RST			BIT(1)
> +
> +#define IE			0x30

Register name is too short. add prefix for it.

> +
> +#define DRIVER_NAME		"imx95-pixel-interleaver"

Only use once, needn't it.

> +
> +struct imx95_pixel_interleaver_bridge {
> +	struct drm_bridge bridge;
> +	struct drm_bridge *next_bridge;
> +	struct device *dev;
> +	void __iomem *regs;
> +	struct regmap *regmap;
> +	struct clk *clk_bus;
> +};
> +
> +static void
> +imx95_pixel_interleaver_bridge_sw_reset(struct imx95_pixel_interleaver_bridge *pi)
> +{
> +	clk_prepare_enable(pi->clk_bus);

need check ret value.

> +
> +	writel(SW_RST, pi->regs + SWRST);
> +	usleep_range(10, 20);
> +	writel(0, pi->regs + SWRST);
> +
> +	clk_disable_unprepare(pi->clk_bus);
> +}
> +
> +static int
> +imx95_pixel_interleaver_bridge_attach(struct drm_bridge *bridge,
> +					     struct drm_encoder *encoder,
> +					     enum drm_bridge_attach_flags flags)
> +{
> +	struct imx95_pixel_interleaver_bridge *pi = bridge->driver_private;
> +
> +	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
> +		dev_err(pi->dev, "do not support creating a drm_connector\n");
> +		return -EINVAL;
> +	}
> +
> +	return drm_bridge_attach(encoder, pi->next_bridge, bridge,
> +				 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> +}
> +
> +static void
> +imx95_pixel_interleaver_bridge_mode_set(struct drm_bridge *bridge,
> +					       const struct drm_display_mode *mode,
> +					       const struct drm_display_mode *adjusted_mode)
> +{
> +	struct imx95_pixel_interleaver_bridge *pi = bridge->driver_private;
> +
> +	imx95_pixel_interleaver_bridge_sw_reset(pi);
> +
> +	clk_prepare_enable(pi->clk_bus);
> +
> +	/* HSYNC and VSYNC are active low. Data Enable is active high */
> +	writel(HSYNC_POLARITY | VSYNC_POLARITY, pi->regs + CTRL);
> +
> +	/* Disable interrupts */
> +	writel(0, pi->regs + IE);
> +
> +	clk_disable_unprepare(pi->clk_bus);
> +}
> +
> +static void
> +imx95_pixel_interleaver_bridge_enable(struct drm_bridge *bridge)
> +{
> +	struct imx95_pixel_interleaver_bridge *pi = bridge->driver_private;
> +
> +	regmap_write(pi->regmap, PIXEL_INTERLEAVER_CTRL, 0);

Look like it can use standard reset interface

Frank
> +}
> +
> +static u32 *
> +imx95_pixel_interleaver_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
> +							 struct drm_bridge_state *bridge_state,
> +							 struct drm_crtc_state *crtc_state,
> +							 struct drm_connector_state *conn_state,
> +							 u32 output_fmt,
> +							 unsigned int *num_input_fmts)
> +{
> +	u32 *input_fmts;
> +
> +	if (output_fmt != MEDIA_BUS_FMT_RGB888_1X24)
> +		return NULL;
> +
> +	*num_input_fmts = 1;
> +
> +	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
> +	if (!input_fmts)
> +		return NULL;
> +
> +	input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
> +
> +	return input_fmts;
> +}
> +
> +static const struct drm_bridge_funcs imx95_pixel_interleaver_bridge_funcs = {
> +	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
> +	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
> +	.atomic_reset		= drm_atomic_helper_bridge_reset,
> +	.attach			= imx95_pixel_interleaver_bridge_attach,
> +	.mode_set		= imx95_pixel_interleaver_bridge_mode_set,
> +	.enable			= imx95_pixel_interleaver_bridge_enable,
> +	.atomic_get_input_bus_fmts =
> +				imx95_pixel_interleaver_bridge_atomic_get_input_bus_fmts,
> +};
> +
> +static int imx95_pixel_interleaver_bridge_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *remote, *remote_port, *np = dev->of_node;
> +	struct imx95_pixel_interleaver_bridge *pi;
> +
> +	pi = devm_drm_bridge_alloc(dev, struct imx95_pixel_interleaver_bridge, bridge,
> +				   &imx95_pixel_interleaver_bridge_funcs);
> +	if (IS_ERR(pi))
> +		return PTR_ERR(pi);
> +
> +	pi->dev = dev;
> +	platform_set_drvdata(pdev, pi);
> +
> +	pi->regs = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(pi->regs))
> +		return PTR_ERR(pi->regs);
> +
> +	pi->regmap = syscon_regmap_lookup_by_phandle(np, "fsl,syscon");
> +	if (IS_ERR(pi->regmap))
> +		return dev_err_probe(dev, PTR_ERR(pi->regmap), "failed to get regmap\n");
> +
> +	pi->clk_bus = devm_clk_get(dev, NULL);
> +	if (IS_ERR(pi->clk_bus))
> +		return dev_err_probe(dev, PTR_ERR(pi->clk_bus), "failed to get clock\n");
> +
> +	pi->bridge.driver_private = pi;
> +	pi->bridge.of_node = np;
> +
> +	remote = of_graph_get_remote_node(np, 1, 0);
> +	if (!remote)
> +		return dev_err_probe(dev, -EINVAL, "no remote node for port@1 endpoint\n");
> +
> +	remote_port = of_graph_get_port_by_id(remote, 0);
> +	of_node_put(remote);
> +	if (!remote_port)
> +		return dev_err_probe(dev, -EINVAL, "no remote port\n");
> +
> +	pi->next_bridge = of_drm_find_bridge(remote_port);
> +	of_node_put(remote_port);
> +	if (!pi->next_bridge) {
> +		dev_err(dev, "failed to find next bridge for port@1 endpoint\n");
> +		return -EPROBE_DEFER;
> +	}
> +
> +	imx95_pixel_interleaver_bridge_sw_reset(pi);
> +
> +	drm_bridge_add(&pi->bridge);
> +
> +	return 0;
> +}
> +
> +static void imx95_pixel_interleaver_bridge_remove(struct platform_device *pdev)
> +{
> +	struct imx95_pixel_interleaver_bridge *pi = platform_get_drvdata(pdev);
> +
> +	drm_bridge_remove(&pi->bridge);
> +}
> +
> +static const struct of_device_id imx95_pixel_interleaver_bridge_dt_ids[] = {
> +	{ .compatible = "fsl,imx95-pixel-interleaver", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, imx95_pixel_interleaver_bridge_dt_ids);
> +
> +static struct platform_driver imx95_pixel_interleaver_bridge_driver = {
> +	.probe	= imx95_pixel_interleaver_bridge_probe,
> +	.remove	= imx95_pixel_interleaver_bridge_remove,
> +	.driver	= {
> +		.of_match_table = imx95_pixel_interleaver_bridge_dt_ids,
> +		.name = DRIVER_NAME,
> +	},
> +};
> +
> +module_platform_driver(imx95_pixel_interleaver_bridge_driver);
> +
> +MODULE_DESCRIPTION("i.MX95 display pixel interleaver bridge driver");
> +MODULE_AUTHOR("NXP Semiconductor");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:" DRIVER_NAME);

Drop it, see
https://lore.kernel.org/imx/daf6fb72-5849-49f7-b17a-818944eb9f1e@kernel.org/

> --
> 2.51.0
>