[PATCH v4 0/4] Add MIPI CSI-2 support for i.MX8ULP

[PATCH v4 0/4] Add MIPI CSI-2 support for i.MX8ULP

[Guoniu Zhou]

The serial adds MIPI CSI-2 support for i.MX8ULP.

Signed-off-by: Guoniu Zhou <guoniu.zhou@nxp.com>
---
Changes in v4:
- Change csr clock name to pclk which is more readability.
- Add restriction to i.MX8ULP and the other variants remain the same as previous versions.
- Update commit log in patch 1 to describe why add new compatible string for i.MX8ULP.
- Link to v3: https://lore.kernel.org/all/20250825-csi2_imx8ulp-v3-0-35885aba62bc@nxp.com

Changes in v3:
- Correct the order of "fsl,imx8qm-mipi-csi2","fsl,imx8qm-mipi-csi2".
- Correct the order of minItems and maxItems.
- Restict all variants.
- Change pclk clock name to csr to match IP port name.
- Align description about csr clock with IP datasheet.
- Add reasons for adding a fourth clock(csr) in patch 1 commit log.
- Link to v2: https://lore.kernel.org/all/20250822-csi2_imx8ulp-v2-0-26a444394965@nxp.com

Changes in v2:
- Add more description about pclk clock.
- Change minItems/maxItems to 2 for resets property.
- Better to handle "fsl,imx8ulp-mipi-csi2" variant.
- Move comment to the top of reset_control_deassert().
- Move dts patch as the last one.
- Add "fsl,imx8qxp-mipi-csi2" to compatible string list of csi node.
- Remove patch 5 in v1.
- Link to v1: https://lore.kernel.org/all/20250812081923.1019345-1-guoniu.zhou@oss.nxp.com

---
Guoniu Zhou (4):
      media: dt-bindings: nxp,imx8mq-mipi-csi2: Add i.MX8ULP compatible string
      media: imx8mq-mipi-csi2: Use devm_clk_bulk_get_all() to fetch clocks
      media: imx8mq-mipi-csi2: Explicitly release reset
      arm64: dts: imx8ulp: Add CSI and ISI Nodes

 .../bindings/media/nxp,imx8mq-mipi-csi2.yaml       | 46 ++++++++++++++-
 arch/arm64/boot/dts/freescale/imx8ulp.dtsi         | 67 ++++++++++++++++++++++
 drivers/media/platform/nxp/imx8mq-mipi-csi2.c      | 60 ++++++-------------
 3 files changed, 128 insertions(+), 45 deletions(-)
---
base-commit: a75b8d198c55e9eb5feb6f6e155496305caba2dc
change-id: 20250819-csi2_imx8ulp-9db386dd6bdf

Best regards,
-- 
Guoniu Zhou <guoniu.zhou@nxp.com>

[PATCH v4 1/4] media: dt-bindings: nxp,imx8mq-mipi-csi2: Add i.MX8ULP compatible string

[Guoniu Zhou]

The CSI-2 receiver in the i.MX8ULP is almost identical to the version
present in the i.MX8QXP/QM, but i.MX8ULP CSI-2 controller needs pclk
clock as the input clock for its APB interface of Control and Status
register(CSR). So add compatible string fsl,imx8ulp-mipi-csi2 and
increase maxItems of Clocks (clock-names) to 4 from 3.  And keep the
same restriction for existed compatible.

Signed-off-by: Guoniu Zhou <guoniu.zhou@nxp.com>
---
 .../bindings/media/nxp,imx8mq-mipi-csi2.yaml       | 46 +++++++++++++++++++++-
 1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/media/nxp,imx8mq-mipi-csi2.yaml b/Documentation/devicetree/bindings/media/nxp,imx8mq-mipi-csi2.yaml
index 3389bab266a9adbda313c8ad795b998641df12f3..38900e76553f639036815c1ae5d97f4dc46f5b13 100644
--- a/Documentation/devicetree/bindings/media/nxp,imx8mq-mipi-csi2.yaml
+++ b/Documentation/devicetree/bindings/media/nxp,imx8mq-mipi-csi2.yaml
@@ -21,7 +21,9 @@ properties:
           - fsl,imx8mq-mipi-csi2
           - fsl,imx8qxp-mipi-csi2
       - items:
-          - const: fsl,imx8qm-mipi-csi2
+          - enum:
+              - fsl,imx8qm-mipi-csi2
+              - fsl,imx8ulp-mipi-csi2
           - const: fsl,imx8qxp-mipi-csi2
 
   reg:
@@ -39,12 +41,16 @@ properties:
                      clock that the RX DPHY receives.
       - description: ui is the pixel clock (phy_ref up to 333Mhz).
                      See the reference manual for details.
+      - description: pclk is clock for csr APB interface.
+    minItems: 3
 
   clock-names:
     items:
       - const: core
       - const: esc
       - const: ui
+      - const: pclk
+    minItems: 3
 
   power-domains:
     maxItems: 1
@@ -125,19 +131,55 @@ required:
   - ports
 
 allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - fsl,imx8ulp-mipi-csi2
+    then:
+      properties:
+        reg:
+          minItems: 2
+        resets:
+          minItems: 2
+          maxItems: 2
+        clocks:
+          minItems: 4
+        clock-names:
+          minItems: 4
+    else:
+      properties:
+        clocks:
+          maxItems: 3
+        clock-names:
+          maxItems: 3
+
   - if:
       properties:
         compatible:
           contains:
             enum:
               - fsl,imx8qxp-mipi-csi2
+              - fsl,imx8qm-mipi-csi2
+          not:
+            contains:
+              enum:
+                - fsl,imx8ulp-mipi-csi2
     then:
       properties:
         reg:
           minItems: 2
         resets:
           maxItems: 1
-    else:
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - fsl,imx8mq-mipi-csi2
+    then:
       properties:
         reg:
           maxItems: 1

-- 
2.34.1

[PATCH v4 2/4] media: imx8mq-mipi-csi2: Use devm_clk_bulk_get_all() to fetch clocks

[Guoniu Zhou]

Use devm_clk_bulk_get_all() helper to simplify clock handle code.

No functional changes intended.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Guoniu Zhou <guoniu.zhou@nxp.com>
---
 drivers/media/platform/nxp/imx8mq-mipi-csi2.c | 52 ++++++++-------------------
 1 file changed, 15 insertions(+), 37 deletions(-)

diff --git a/drivers/media/platform/nxp/imx8mq-mipi-csi2.c b/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
index 3a4645f59a44028fdca82a4d8393e1a0a6ba88f0..2bf11984690af2e687a3217e465697333d9d995d 100644
--- a/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
+++ b/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
@@ -71,21 +71,6 @@ enum {
 	ST_SUSPENDED	= 4,
 };
 
-enum imx8mq_mipi_csi_clk {
-	CSI2_CLK_CORE,
-	CSI2_CLK_ESC,
-	CSI2_CLK_UI,
-	CSI2_NUM_CLKS,
-};
-
-static const char * const imx8mq_mipi_csi_clk_id[CSI2_NUM_CLKS] = {
-	[CSI2_CLK_CORE] = "core",
-	[CSI2_CLK_ESC] = "esc",
-	[CSI2_CLK_UI] = "ui",
-};
-
-#define CSI2_NUM_CLKS	ARRAY_SIZE(imx8mq_mipi_csi_clk_id)
-
 struct imx8mq_plat_data {
 	int (*enable)(struct csi_state *state, u32 hs_settle);
 	void (*disable)(struct csi_state *state);
@@ -111,7 +96,8 @@ struct csi_state {
 	struct device *dev;
 	const struct imx8mq_plat_data *pdata;
 	void __iomem *regs;
-	struct clk_bulk_data clks[CSI2_NUM_CLKS];
+	struct clk_bulk_data *clks;
+	int num_clks;
 	struct reset_control *rst;
 	struct regulator *mipi_phy_regulator;
 
@@ -384,24 +370,16 @@ static void imx8mq_mipi_csi_set_params(struct csi_state *state)
 			      CSI2RX_SEND_LEVEL);
 }
 
-static int imx8mq_mipi_csi_clk_enable(struct csi_state *state)
-{
-	return clk_bulk_prepare_enable(CSI2_NUM_CLKS, state->clks);
-}
-
-static void imx8mq_mipi_csi_clk_disable(struct csi_state *state)
+static struct clk *find_esc_clk(struct csi_state *state)
 {
-	clk_bulk_disable_unprepare(CSI2_NUM_CLKS, state->clks);
-}
-
-static int imx8mq_mipi_csi_clk_get(struct csi_state *state)
-{
-	unsigned int i;
+	int i;
 
-	for (i = 0; i < CSI2_NUM_CLKS; i++)
-		state->clks[i].id = imx8mq_mipi_csi_clk_id[i];
+	for (i = 0; i < state->num_clks; i++) {
+		if (!strcmp(state->clks[i].id, "esc"))
+			return state->clks[i].clk;
+	}
 
-	return devm_clk_bulk_get(state->dev, CSI2_NUM_CLKS, state->clks);
+	return NULL;
 }
 
 static int imx8mq_mipi_csi_calc_hs_settle(struct csi_state *state,
@@ -456,7 +434,7 @@ static int imx8mq_mipi_csi_calc_hs_settle(struct csi_state *state,
 	 * documentation recommends picking a value away from the boundaries.
 	 * Let's pick the average.
 	 */
-	esc_clk_rate = clk_get_rate(state->clks[CSI2_CLK_ESC].clk);
+	esc_clk_rate = clk_get_rate(find_esc_clk(state));
 	if (!esc_clk_rate) {
 		dev_err(state->dev, "Could not get esc clock rate.\n");
 		return -EINVAL;
@@ -783,7 +761,7 @@ static void imx8mq_mipi_csi_pm_suspend(struct device *dev)
 
 	if (state->state & ST_POWERED) {
 		imx8mq_mipi_csi_stop_stream(state);
-		imx8mq_mipi_csi_clk_disable(state);
+		clk_bulk_disable_unprepare(state->num_clks, state->clks);
 		state->state &= ~ST_POWERED;
 	}
 
@@ -801,7 +779,7 @@ static int imx8mq_mipi_csi_pm_resume(struct device *dev)
 
 	if (!(state->state & ST_POWERED)) {
 		state->state |= ST_POWERED;
-		ret = imx8mq_mipi_csi_clk_enable(state);
+		ret = clk_bulk_prepare_enable(state->num_clks, state->clks);
 	}
 	if (state->state & ST_STREAMING) {
 		sd_state = v4l2_subdev_lock_and_get_active_state(sd);
@@ -1027,9 +1005,9 @@ static int imx8mq_mipi_csi_probe(struct platform_device *pdev)
 	if (IS_ERR(state->regs))
 		return PTR_ERR(state->regs);
 
-	ret = imx8mq_mipi_csi_clk_get(state);
-	if (ret < 0)
-		return ret;
+	state->num_clks = devm_clk_bulk_get_all(dev, &state->clks);
+	if (state->num_clks < 0)
+		return dev_err_probe(dev, state->num_clks, "Failed to get clocks\n");
 
 	platform_set_drvdata(pdev, &state->sd);
 

-- 
2.34.1

[PATCH v4 3/4] media: imx8mq-mipi-csi2: Explicitly release reset

[Guoniu Zhou]

Call reset_control_deassert() to explicitly release reset to make sure
reset bits are cleared since platform like i.MX8ULP can't clear reset
bits automatically.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Guoniu Zhou <guoniu.zhou@nxp.com>
---
 drivers/media/platform/nxp/imx8mq-mipi-csi2.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/media/platform/nxp/imx8mq-mipi-csi2.c b/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
index 2bf11984690af2e687a3217e465697333d9d995d..6b83aa85af42e1dac25cf29056863680c1f89402 100644
--- a/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
+++ b/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
@@ -337,18 +337,14 @@ static int imx8mq_mipi_csi_sw_reset(struct csi_state *state)
 {
 	int ret;
 
-	/*
-	 * these are most likely self-clearing reset bits. to make it
-	 * more clear, the reset-imx7 driver should implement the
-	 * .reset() operation.
-	 */
 	ret = reset_control_assert(state->rst);
 	if (ret < 0) {
 		dev_err(state->dev, "Failed to assert resets: %d\n", ret);
 		return ret;
 	}
 
-	return 0;
+	/* Explicitly release reset to make sure reset bits are cleared. */
+	return reset_control_deassert(state->rst);
 }
 
 static void imx8mq_mipi_csi_set_params(struct csi_state *state)

-- 
2.34.1

[PATCH v4 4/4] arm64: dts: imx8ulp: Add CSI and ISI Nodes

[Guoniu Zhou]

The CSI-2 in the i.MX8ULP is almost identical to the version present
in the i.MX8QXP/QM and is routed to the ISI. Add both the ISI and CSI
nodes and mark them as disabled by default since capture is dependent
on an attached camera.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Guoniu Zhou <guoniu.zhou@nxp.com>
---
 arch/arm64/boot/dts/freescale/imx8ulp.dtsi | 67 ++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8ulp.dtsi b/arch/arm64/boot/dts/freescale/imx8ulp.dtsi
index 13b01f3aa2a4950c37e72e04f6bfb5995dc19178..7981f7dc62f5dfb2dff051e2d91bde6a2498ac13 100644
--- a/arch/arm64/boot/dts/freescale/imx8ulp.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8ulp.dtsi
@@ -7,6 +7,7 @@
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/interrupt-controller/arm-gic.h>
 #include <dt-bindings/power/imx8ulp-power.h>
+#include <dt-bindings/reset/imx8ulp-pcc-reset.h>
 #include <dt-bindings/thermal/thermal.h>
 
 #include "imx8ulp-pinfunc.h"
@@ -842,6 +843,72 @@ spdif: spdif@2dab0000 {
 				dma-names = "rx", "tx";
 				status = "disabled";
 			};
+
+			isi: isi@2dac0000 {
+				compatible = "fsl,imx8ulp-isi";
+				reg = <0x2dac0000 0x10000>;
+				interrupts = <GIC_SPI 119 IRQ_TYPE_LEVEL_HIGH>;
+				clocks = <&pcc5 IMX8ULP_CLK_ISI>,
+					 <&cgc2 IMX8ULP_CLK_LPAV_AXI_DIV>;
+				clock-names = "axi", "apb";
+				power-domains = <&scmi_devpd IMX8ULP_PD_ISI>;
+				status = "disabled";
+
+				ports {
+					#address-cells = <1>;
+					#size-cells = <0>;
+
+					port@0 {
+						reg = <0>;
+						isi_in: endpoint {
+							remote-endpoint = <&mipi_csi_out>;
+						};
+					};
+				};
+			};
+
+			mipi_csi: csi@2daf0000 {
+				compatible = "fsl,imx8ulp-mipi-csi2", "fsl,imx8qxp-mipi-csi2";
+				reg = <0x2daf0000 0x10000>,
+				      <0x2dad0000 0x10000>;
+				clocks = <&pcc5 IMX8ULP_CLK_CSI>,
+					 <&pcc5 IMX8ULP_CLK_CSI_CLK_ESC>,
+					 <&pcc5 IMX8ULP_CLK_CSI_CLK_UI>,
+					 <&pcc5 IMX8ULP_CLK_CSI_REGS>;
+				clock-names = "core", "esc", "ui", "pclk";
+				assigned-clocks = <&pcc5 IMX8ULP_CLK_CSI>,
+						  <&pcc5 IMX8ULP_CLK_CSI_CLK_ESC>,
+						  <&pcc5 IMX8ULP_CLK_CSI_CLK_UI>,
+						  <&pcc5 IMX8ULP_CLK_CSI_REGS>;
+				assigned-clock-parents = <&cgc2 IMX8ULP_CLK_PLL4_PFD1_DIV1>,
+							 <&cgc2 IMX8ULP_CLK_PLL4_PFD1_DIV2>,
+							 <&cgc2 IMX8ULP_CLK_PLL4_PFD0_DIV1>;
+				assigned-clock-rates = <200000000>,
+						       <80000000>,
+						       <100000000>,
+						       <79200000>;
+				power-domains = <&scmi_devpd IMX8ULP_PD_MIPI_CSI>;
+				resets = <&pcc5 PCC5_CSI_SWRST>,
+					 <&pcc5 PCC5_CSI_REGS_SWRST>;
+				status = "disabled";
+
+				ports {
+					#address-cells = <1>;
+					#size-cells = <0>;
+
+					port@0 {
+						reg = <0>;
+					};
+
+					port@1 {
+						reg = <1>;
+
+						mipi_csi_out: endpoint {
+							remote-endpoint = <&isi_in>;
+						};
+					};
+				};
+			};
 		};
 
 		gpiod: gpio@2e200000 {

-- 
2.34.1

Re: [PATCH v4 1/4] media: dt-bindings: nxp,imx8mq-mipi-csi2: Add i.MX8ULP compatible string

[Krzysztof Kozlowski]

On Thu, Aug 28, 2025 at 03:17:33PM +0800, Guoniu Zhou wrote:
>  allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - fsl,imx8ulp-mipi-csi2
> +    then:
> +      properties:
> +        reg:
> +          minItems: 2
> +        resets:
> +          minItems: 2
> +          maxItems: 2
> +        clocks:
> +          minItems: 4
> +        clock-names:
> +          minItems: 4
> +    else:
> +      properties:
> +        clocks:
> +          maxItems: 3
> +        clock-names:
> +          maxItems: 3
> +
>    - if:
>        properties:
>          compatible:
>            contains:
>              enum:
>                - fsl,imx8qxp-mipi-csi2
> +              - fsl,imx8qm-mipi-csi2
> +          not:
> +            contains:
> +              enum:
> +                - fsl,imx8ulp-mipi-csi2

That's a nice trick, but I think you should just list exact cases.

It's also easier to read if if:then: blocks are symmetrical. Your
previous one consgtrained reg+resetes+clocks. This one constrains only
reg+resets.

>      then:
>        properties:
>          reg:
>            minItems: 2
>          resets:
>            maxItems: 1
> -    else:
> +
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - fsl,imx8mq-mipi-csi2
> +    then:
>        properties:
>          reg:
>            maxItems: 1

And this one constraints only "reg".

This stops being readable and maintainable.


Best regards,
Krzysztof