[PATCH v11 0/5] arm64: add Ambarella CV75 SoC support

[PATCH v11 0/5] arm64: add Ambarella CV75 SoC support

[Long Zhao via B4 Relay]

Add the Ambarella CV75 SoC and EVK support: the board binding, the
RCT clock binding and driver, ARCH_AMBARELLA, the devicetree and
MAINTAINERS.

The clock ID header is added before the devicetree that includes it,
so patch 2 (the clock binding) has to be applied before patch 4 (the
devicetree).

The ambarella vendor prefix and the CV75 secure scratchpad syscon
binding are already in linux-next. This series does not repeat
either of them.

GPIO, UART and pinctrl bindings and drivers are separate series.
This devicetree references those compatibles.

Tested on the CV75 EVK. The board boots. That boot used a local tree
that also includes the GPIO, UART and pinctrl patches.

To: Arnd Bergmann <arnd@arndb.de>
To: Krzysztof Kozlowski <krzk@kernel.org>
To: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: soc@lists.linux.dev
To: linux-arm-kernel@lists.infradead.org
To: Michael Turquette <mturquette@baylibre.com>
To: Stephen Boyd <sboyd@kernel.org>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: linux-clk@vger.kernel.org
Cc: Brian Masney <masneyb@kernel.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: devicetree@vger.kernel.org
Cc: Long Zhao <longzhao@ambarella.com>
Cc: Long Zhao <zl020895@163.com>
Cc: linux-kernel@vger.kernel.org

Signed-off-by: Long Zhao <longzhao@ambarella.com>
---
Changes in v11:
- clk: use builtin_platform_driver(). The Kconfig symbol is bool. (Brian)
- clk: drop CLK_IS_CRITICAL from the core PLL. It has no enable op. (Brian)
- clk: drop the misleading (u64) cast in the div_u64() call. (Brian)
- clk: add .suppress_bind_attrs = true to block sysfs unbind. (Brian)
- clk: drop MODULE_AUTHOR. (Brian)
- Link to v10:
  https://patch.msgid.link/20261019-cv75-soc-v10-0-d386065e2dd5@ambarella.com

---
Long Zhao (5):
      dt-bindings: arm: add Ambarella CV75 platforms
      dt-bindings: clock: add Ambarella CV75 RCT
      clk: ambarella: add CV75 RCT clock controller
      arm64: ambarella: add ARCH_AMBARELLA and CV75 EVK DT
      MAINTAINERS: add ARM/AMBARELLA SoC support

 .../devicetree/bindings/arm/ambarella.yaml         |  24 ++
 .../bindings/clock/ambarella,cv75-rct.yaml         |  64 ++++
 MAINTAINERS                                        |  14 +
 arch/arm64/Kconfig.platforms                       |   6 +
 arch/arm64/boot/dts/Makefile                       |   1 +
 arch/arm64/boot/dts/ambarella/Makefile             |   3 +
 arch/arm64/boot/dts/ambarella/cv75-evk.dts         |  30 ++
 arch/arm64/boot/dts/ambarella/cv75.dtsi            | 177 ++++++++++
 arch/arm64/configs/defconfig                       |   1 +
 drivers/clk/Kconfig                                |   1 +
 drivers/clk/Makefile                               |   1 +
 drivers/clk/ambarella/Kconfig                      |   8 +
 drivers/clk/ambarella/Makefile                     |   3 +
 drivers/clk/ambarella/clk-cv75.c                   | 361 +++++++++++++++++++++
 include/dt-bindings/clock/ambarella,cv75-rct.h     |  14 +
 15 files changed, 708 insertions(+)
---
base-commit: 34cf6dafc47441dfb6b356a095b89c3585a93714
change-id: 20261007-cv75-soc-e628f357f066

Best regards,
--  
Long Zhao <longzhao@ambarella.com>

[PATCH v11 1/5] dt-bindings: arm: add Ambarella CV75 platforms

[Long Zhao via B4 Relay]

From: Long Zhao <longzhao@ambarella.com>

Document the CV75 EVK board compatible for the initial SoC bring-up.
The ambarella vendor prefix is already applied in the devicetree tree.

Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Long Zhao <longzhao@ambarella.com>
---
 .../devicetree/bindings/arm/ambarella.yaml         | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/ambarella.yaml b/Documentation/devicetree/bindings/arm/ambarella.yaml
new file mode 100644
index 000000000000..72946e94fa76
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/ambarella.yaml
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/ambarella.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ambarella SoC platforms
+
+maintainers:
+  - Long Zhao <longzhao@ambarella.com>
+
+properties:
+  $nodename:
+    const: "/"
+
+  compatible:
+    oneOf:
+      - description: Ambarella CV75 boards
+        items:
+          - enum:
+              - ambarella,cv75-evk
+          - const: ambarella,cv75
+
+additionalProperties: true

-- 
2.34.1

[PATCH v11 2/5] dt-bindings: clock: add Ambarella CV75 RCT

[Long Zhao via B4 Relay]

From: Long Zhao <longzhao@ambarella.com>

Document the CV75 RCT clock controller and the clock ID header used by
DT consumers.

Document #reset-cells for the RCT reset-provider role. Soft-reset line
IDs and the reset provider driver are deferred; this series has no
resets= consumers.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Long Zhao <longzhao@ambarella.com>
---
 .../bindings/clock/ambarella,cv75-rct.yaml         | 64 ++++++++++++++++++++++
 include/dt-bindings/clock/ambarella,cv75-rct.h     | 14 +++++
 2 files changed, 78 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/ambarella,cv75-rct.yaml b/Documentation/devicetree/bindings/clock/ambarella,cv75-rct.yaml
new file mode 100644
index 000000000000..be89bd75f9e2
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/ambarella,cv75-rct.yaml
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/ambarella,cv75-rct.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ambarella CV75 RCT Clock Controller
+
+maintainers:
+  - Long Zhao <longzhao@ambarella.com>
+
+description: |
+  The RCT (Reset and Clock Tree) block on the Ambarella CV75 SoC provides
+  PLLs, clock muxes, dividers and soft-reset controls for on-chip
+  peripherals.
+
+  The same register region is also exposed as a syscon for other SoC
+  blocks (e.g. pin drive-strength), hence the "syscon" compatible.
+
+  Clock indices are defined in include/dt-bindings/clock/ambarella,cv75-rct.h.
+
+properties:
+
+  compatible:
+    items:
+      - const: ambarella,cv75-rct
+      - const: syscon
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    description: Reference crystal oscillator (typically 24 MHz)
+    maxItems: 1
+
+  clock-names:
+    const: osc
+
+  "#clock-cells":
+    const: 1
+
+  "#reset-cells":
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - "#clock-cells"
+  - "#reset-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    clock-controller@ed080000 {
+        compatible = "ambarella,cv75-rct", "syscon";
+        reg = <0xed080000 0x1000>;
+        clocks = <&osc>;
+        clock-names = "osc";
+        #clock-cells = <1>;
+        #reset-cells = <1>;
+    };
diff --git a/include/dt-bindings/clock/ambarella,cv75-rct.h b/include/dt-bindings/clock/ambarella,cv75-rct.h
new file mode 100644
index 000000000000..b3e965b4ff2e
--- /dev/null
+++ b/include/dt-bindings/clock/ambarella,cv75-rct.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause */
+/*
+ * Copyright (C) 2026 Ambarella, Inc.
+ */
+
+#ifndef _DT_BINDINGS_CLOCK_AMBARELLA_CV75_RCT_H
+#define _DT_BINDINGS_CLOCK_AMBARELLA_CV75_RCT_H
+
+#define CV75_GCLK_UART0		0
+#define CV75_GCLK_CORE		1
+#define CV75_GCLK_AHB		2
+#define CV75_GCLK_APB		3
+
+#endif

-- 
2.34.1

[PATCH v11 3/5] clk: ambarella: add CV75 RCT clock controller

[Long Zhao via B4 Relay]

From: Long Zhao <longzhao@ambarella.com>

Add a table-driven CCF driver for the CV75 root clock tree. Register
the core PLL, AHB/APB fixed factors and UART0 composite clock, with
osc supplied via clk_parent_data.

Signed-off-by: Long Zhao <longzhao@ambarella.com>
---
 drivers/clk/Kconfig              |   1 +
 drivers/clk/Makefile             |   1 +
 drivers/clk/ambarella/Kconfig    |   8 +
 drivers/clk/ambarella/Makefile   |   3 +
 drivers/clk/ambarella/clk-cv75.c | 361 +++++++++++++++++++++++++++++++++++++++
 5 files changed, 374 insertions(+)

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 1717ce75a907..fbbf4963716c 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -506,6 +506,7 @@ config COMMON_CLK_RPMI
 	  the RISC-V platform management interface (RPMI) specification.
 
 source "drivers/clk/actions/Kconfig"
+source "drivers/clk/ambarella/Kconfig"
 source "drivers/clk/analogbits/Kconfig"
 source "drivers/clk/aspeed/Kconfig"
 source "drivers/clk/bcm/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index cc108a75a900..30d823ee606f 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -112,6 +112,7 @@ obj-$(CONFIG_COMMON_CLK_XGENE)		+= clk-xgene.o
 
 # please keep this section sorted lexicographically by directory path name
 obj-y					+= actions/
+obj-y					+= ambarella/
 obj-y					+= analogbits/
 obj-y					+= aspeed/
 obj-$(CONFIG_COMMON_CLK_AT91)		+= at91/
diff --git a/drivers/clk/ambarella/Kconfig b/drivers/clk/ambarella/Kconfig
new file mode 100644
index 000000000000..fb1d91a2954c
--- /dev/null
+++ b/drivers/clk/ambarella/Kconfig
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config CLK_AMBARELLA_CV75
+	bool "Ambarella CV75 RCT clock controller"
+	depends on ARCH_AMBARELLA || COMPILE_TEST
+	default ARCH_AMBARELLA
+	help
+	  Say Y here to enable the Ambarella CV75 RCT clock controller.
diff --git a/drivers/clk/ambarella/Makefile b/drivers/clk/ambarella/Makefile
new file mode 100644
index 000000000000..29555e452441
--- /dev/null
+++ b/drivers/clk/ambarella/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_CLK_AMBARELLA_CV75) += clk-cv75.o
diff --git a/drivers/clk/ambarella/clk-cv75.c b/drivers/clk/ambarella/clk-cv75.c
new file mode 100644
index 000000000000..c23c60c4fd6f
--- /dev/null
+++ b/drivers/clk/ambarella/clk-cv75.c
@@ -0,0 +1,361 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Ambarella CV75 RCT clock controller
+ *
+ * Copyright (C) 2026 Ambarella, Inc.
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk-provider.h>
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/overflow.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <dt-bindings/clock/ambarella,cv75-rct.h>
+
+#define CV75_NUM_CLKS		(CV75_GCLK_APB + 1)
+
+#define PLL_CTRL_BYPASS		BIT(2)
+#define PLL_CTRL_FRAC_MODE	BIT(3)
+#define PLL_CTRL_FORCE_RESET	BIT(4)
+#define PLL_CTRL_POWER_DOWN	BIT(5)
+#define PLL_CTRL_HALT_VCO	BIT(6)
+#define PLL_CTRL_SDIV		GENMASK(15, 12)
+#define PLL_CTRL_SOUT		GENMASK(19, 16)
+#define PLL_CTRL_INTP		GENMASK(30, 24)
+
+#define PLL_CTRL2_VCODIV_DIV2	BIT(8)
+#define PLL_CTRL2_FSDIV_DIV2	BIT(9)
+#define PLL_CTRL2_FSOUT_DIV2	BIT(11)
+#define PLL_CTRL2_BYPASS_HSDIV	BIT(12)
+
+struct cv75_pll_regs {
+	u32 ctrl;
+	u32 frac;
+	u32 ctrl2;
+};
+
+struct cv75_pll_hw {
+	struct clk_hw hw;
+	struct cv75_pll_regs regs;
+};
+
+struct cv75_clk {
+	void __iomem *base;
+	spinlock_t lock;
+	struct cv75_pll_hw core;
+	struct cv75_pll_hw enet;
+	struct cv75_pll_hw sd;
+};
+
+struct cv75_pll {
+	const char *name;
+	struct cv75_pll_hw *hw;
+	unsigned long flags;
+	struct cv75_pll_regs regs;
+	int id;
+};
+
+struct cv75_fixed_factor {
+	const char *name;
+	u32 id;
+	struct u16_fract ratio;
+};
+
+struct cv75_composite {
+	const char *name;
+	const struct clk_parent_data *parents;
+	unsigned long flags;
+	u32 id;
+	u16 mux_reg;
+	u16 div_reg;
+	u8 num_parents;
+	u8 mux_shift;
+	u8 mux_width;
+	u8 div_shift;
+	u8 div_width;
+};
+
+struct cv75_composite_hw {
+	struct clk_mux mux;
+	struct clk_divider div;
+	struct clk_gate gate;
+};
+
+static struct cv75_clk cv75_ccu;
+
+#define CV75_PLL(_id, _name, _ctrl, _frac, _ctrl2, _flags, _hw) {	\
+	.name	= _name,						\
+	.hw	= _hw,							\
+	.flags	= _flags,						\
+	.regs	= {							\
+		.ctrl = _ctrl,						\
+		.frac = _frac,						\
+		.ctrl2 = _ctrl2,					\
+	},								\
+	.id	= _id,							\
+}
+
+static const struct cv75_pll cv75_plls[] = {
+	CV75_PLL(CV75_GCLK_CORE, "core", 0x000, 0x004, 0x100,
+		 0, &cv75_ccu.core),
+	CV75_PLL(-1, "pll_enet", 0x520, 0x524, 0x528,
+		 0, &cv75_ccu.enet),
+	CV75_PLL(-1, "pll_sd", 0x4ac, 0x4b0, 0x4b4,
+		 0, &cv75_ccu.sd),
+};
+
+static const struct cv75_fixed_factor cv75_fixed_factors[] = {
+	{ .id = CV75_GCLK_AHB, .name = "ahb", .ratio = { 1, 2 } },
+	{ .id = CV75_GCLK_APB, .name = "apb", .ratio = { 1, 4 } },
+};
+
+static const struct clk_parent_data cv75_uart_parents[] = {
+	{ .fw_name = "osc" },
+	{ .hw = &cv75_ccu.core.hw },
+	{ .hw = &cv75_ccu.enet.hw },
+	{ .hw = &cv75_ccu.sd.hw },
+};
+
+#define CV75_COMPOSITE(_id, _name, _parents, _mreg, _mshift, _mwidth,	\
+		       _dreg, _dshift, _dwidth, _flags)			\
+{									\
+	.id		= _id,						\
+	.name		= _name,					\
+	.parents	= _parents,					\
+	.num_parents	= ARRAY_SIZE(_parents),				\
+	.mux_reg	= _mreg,					\
+	.mux_shift	= _mshift,					\
+	.mux_width	= _mwidth,					\
+	.div_reg	= _dreg,					\
+	.div_shift	= _dshift,					\
+	.div_width	= _dwidth,					\
+	.flags		= _flags,					\
+}
+
+static const struct cv75_composite cv75_composites[] = {
+	CV75_COMPOSITE(CV75_GCLK_UART0, "uart0", cv75_uart_parents,
+		       0x1c8, 0, 2, 0x038, 0, 24,
+		       CLK_SET_RATE_NO_REPARENT),
+};
+
+#define to_cv75_pll(_hw) container_of(_hw, struct cv75_pll_hw, hw)
+
+static unsigned long cv75_pll_recalc_rate(struct clk_hw *hw,
+					  unsigned long parent_rate)
+{
+	struct cv75_pll_hw *pll = to_cv75_pll(hw);
+	u32 ctrl, ctrl2, frac_val;
+	u32 vcodiv, fsdiv, fsout;
+	u32 intp, sdiv, sout;
+	u64 vco, frac = 0;
+
+	ctrl = readl_relaxed(cv75_ccu.base + pll->regs.ctrl);
+	if (ctrl & (PLL_CTRL_POWER_DOWN | PLL_CTRL_HALT_VCO | PLL_CTRL_FORCE_RESET))
+		return 0;
+
+	if (ctrl & PLL_CTRL_BYPASS)
+		return parent_rate;
+
+	ctrl2 = readl_relaxed(cv75_ccu.base + pll->regs.ctrl2);
+	intp = FIELD_GET(PLL_CTRL_INTP, ctrl) + 1;
+	sdiv = FIELD_GET(PLL_CTRL_SDIV, ctrl) + 1;
+	sout = FIELD_GET(PLL_CTRL_SOUT, ctrl) + 1;
+	vcodiv = (ctrl2 & PLL_CTRL2_VCODIV_DIV2) ? 2 : 1;
+	fsdiv = (ctrl2 & PLL_CTRL2_FSDIV_DIV2) ? 2 : 1;
+	fsout = (ctrl2 & PLL_CTRL2_FSOUT_DIV2) ? 2 : 1;
+
+	vco = (u64)parent_rate * vcodiv * fsdiv * intp * sdiv;
+	if (ctrl & PLL_CTRL_FRAC_MODE) {
+		frac_val = readl_relaxed(cv75_ccu.base + pll->regs.frac);
+		frac = mul_u64_u32_shr((u64)parent_rate * vcodiv * fsdiv * sdiv,
+				       frac_val, 32);
+		vco += frac;
+	}
+
+	if (!(ctrl2 & PLL_CTRL2_BYPASS_HSDIV))
+		vco = div_u64(vco, vcodiv * fsout * sout);
+
+	return vco;
+}
+
+static const struct clk_ops cv75_pll_ops = {
+	.recalc_rate = cv75_pll_recalc_rate,
+};
+
+static int cv75_register_plls(struct device *dev,
+			      struct clk_hw_onecell_data *data)
+{
+	struct clk_parent_data parent_data = { .fw_name = "osc" };
+
+	for (unsigned int i = 0; i < ARRAY_SIZE(cv75_plls); i++) {
+		const struct cv75_pll *desc = &cv75_plls[i];
+		struct cv75_pll_hw *pll = desc->hw;
+		struct clk_init_data init = {};
+		int ret;
+
+		pll->regs = desc->regs;
+
+		init.name = desc->name;
+		init.ops = &cv75_pll_ops;
+		init.parent_data = &parent_data;
+		init.num_parents = 1;
+		init.flags = desc->flags;
+		pll->hw.init = &init;
+
+		ret = devm_clk_hw_register(dev, &pll->hw);
+		if (ret)
+			return ret;
+
+		if (desc->id >= 0)
+			data->hws[desc->id] = &pll->hw;
+	}
+
+	return 0;
+}
+
+static int cv75_register_fixed_factors(struct device *dev,
+				       struct clk_hw_onecell_data *data)
+{
+	for (unsigned int i = 0; i < ARRAY_SIZE(cv75_fixed_factors); i++) {
+		const struct cv75_fixed_factor *f = &cv75_fixed_factors[i];
+		struct clk_hw *hw;
+
+		hw = devm_clk_hw_register_fixed_factor_parent_hw(dev, f->name,
+								 &cv75_ccu.core.hw, 0,
+								 f->ratio.numerator,
+								 f->ratio.denominator);
+		if (IS_ERR(hw))
+			return PTR_ERR(hw);
+
+		data->hws[f->id] = hw;
+	}
+
+	return 0;
+}
+
+static struct clk_hw *cv75_register_composite(struct device *dev,
+					      const struct cv75_composite *c)
+{
+	const struct clk_ops *mux_ops = NULL, *div_ops = NULL, *gate_ops = NULL;
+	struct clk_hw *mux_hw = NULL, *div_hw = NULL, *gate_hw = NULL;
+	struct cv75_composite_hw *comp;
+
+	comp = devm_kzalloc(dev, sizeof(*comp), GFP_KERNEL);
+	if (!comp)
+		return ERR_PTR(-ENOMEM);
+
+	if (c->mux_width) {
+		comp->mux.reg = cv75_ccu.base + c->mux_reg;
+		comp->mux.shift = c->mux_shift;
+		comp->mux.mask = GENMASK(c->mux_width - 1, 0);
+		comp->mux.lock = &cv75_ccu.lock;
+		mux_hw = &comp->mux.hw;
+		mux_ops = &clk_mux_ops;
+	}
+
+	if (c->div_width) {
+		comp->div.reg = cv75_ccu.base + c->div_reg;
+		comp->div.shift = c->div_shift;
+		comp->div.width = c->div_width;
+		comp->div.flags = CLK_DIVIDER_ONE_BASED;
+		comp->div.lock = &cv75_ccu.lock;
+		div_hw = &comp->div.hw;
+		div_ops = &clk_divider_ops;
+
+		comp->gate.reg = cv75_ccu.base + c->div_reg;
+		comp->gate.bit_idx = c->div_shift + c->div_width;
+		comp->gate.flags = CLK_GATE_SET_TO_DISABLE;
+		comp->gate.lock = &cv75_ccu.lock;
+		gate_hw = &comp->gate.hw;
+		gate_ops = &clk_gate_ops;
+	}
+
+	return devm_clk_hw_register_composite_pdata(dev, c->name, c->parents,
+						    c->num_parents,
+						    mux_hw, mux_ops,
+						    div_hw, div_ops,
+						    gate_hw, gate_ops, c->flags);
+}
+
+static int cv75_register_composites(struct device *dev,
+				    struct clk_hw_onecell_data *data)
+{
+	for (unsigned int i = 0; i < ARRAY_SIZE(cv75_composites); i++) {
+		const struct cv75_composite *c = &cv75_composites[i];
+		struct clk_hw *hw;
+
+		hw = cv75_register_composite(dev, c);
+		if (IS_ERR(hw))
+			return PTR_ERR(hw);
+
+		data->hws[c->id] = hw;
+	}
+
+	return 0;
+}
+
+static int cv75_rct_probe(struct platform_device *pdev)
+{
+	struct clk_hw_onecell_data *data;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	cv75_ccu.base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(cv75_ccu.base))
+		return PTR_ERR(cv75_ccu.base);
+
+	data = devm_kzalloc(dev, struct_size(data, hws, CV75_NUM_CLKS), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+	data->num = CV75_NUM_CLKS;
+
+	spin_lock_init(&cv75_ccu.lock);
+
+	ret = cv75_register_plls(dev, data);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to register plls\n");
+
+	ret = cv75_register_fixed_factors(dev, data);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to register fixed factors\n");
+
+	ret = cv75_register_composites(dev, data);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to register composites\n");
+
+	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, data);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to add clock provider\n");
+
+	return 0;
+}
+
+static const struct of_device_id cv75_rct_match[] = {
+	{ .compatible = "ambarella,cv75-rct" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, cv75_rct_match);
+
+static struct platform_driver cv75_rct_driver = {
+	.probe = cv75_rct_probe,
+	.driver = {
+		.name = "ambarella-cv75-rct",
+		.of_match_table = cv75_rct_match,
+		.suppress_bind_attrs = true,
+	},
+};
+builtin_platform_driver(cv75_rct_driver);
+
+MODULE_DESCRIPTION("Ambarella CV75 RCT clock controller");
+MODULE_LICENSE("GPL");

-- 
2.34.1

[PATCH v11 4/5] arm64: ambarella: add ARCH_AMBARELLA and CV75 EVK DT

[Long Zhao via B4 Relay]

From: Long Zhao <longzhao@ambarella.com>

Enable ARCH_AMBARELLA and add a minimal CV75 SoC / EVK device tree for
console bring-up with the RCT clocks, UART, pinctrl and GPIO banks.

Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Long Zhao <longzhao@ambarella.com>
---
 arch/arm64/Kconfig.platforms               |   6 +
 arch/arm64/boot/dts/Makefile               |   1 +
 arch/arm64/boot/dts/ambarella/Makefile     |   3 +
 arch/arm64/boot/dts/ambarella/cv75-evk.dts |  30 +++++
 arch/arm64/boot/dts/ambarella/cv75.dtsi    | 177 +++++++++++++++++++++++++++++
 arch/arm64/configs/defconfig               |   1 +
 6 files changed, 218 insertions(+)

diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
index d2acfac73003..16d7e3a4c2d6 100644
--- a/arch/arm64/Kconfig.platforms
+++ b/arch/arm64/Kconfig.platforms
@@ -26,6 +26,12 @@ config ARCH_SUNXI
 	help
 	  This enables support for Allwinner sunxi based SoCs like the A64.
 
+config ARCH_AMBARELLA
+	bool "Ambarella SoC family"
+	select PINCTRL
+	help
+	  This enables support for the ARM64 based Ambarella SoCs like CV75.
+
 config ARCH_ALPINE
 	bool "Annapurna Labs Alpine platform"
 	select ALPINE_MSI if PCI
diff --git a/arch/arm64/boot/dts/Makefile b/arch/arm64/boot/dts/Makefile
index fc726b215f12..f1709eb5d915 100644
--- a/arch/arm64/boot/dts/Makefile
+++ b/arch/arm64/boot/dts/Makefile
@@ -4,6 +4,7 @@ subdir-y += airoha
 subdir-y += allwinner
 subdir-y += altera
 subdir-y += amazon
+subdir-y += ambarella
 subdir-y += amd
 subdir-y += amlogic
 subdir-y += apm
diff --git a/arch/arm64/boot/dts/ambarella/Makefile b/arch/arm64/boot/dts/ambarella/Makefile
new file mode 100644
index 000000000000..ddca3d7b18cc
--- /dev/null
+++ b/arch/arm64/boot/dts/ambarella/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+dtb-$(CONFIG_ARCH_AMBARELLA) += cv75-evk.dtb
diff --git a/arch/arm64/boot/dts/ambarella/cv75-evk.dts b/arch/arm64/boot/dts/ambarella/cv75-evk.dts
new file mode 100644
index 000000000000..42a0fe24b83b
--- /dev/null
+++ b/arch/arm64/boot/dts/ambarella/cv75-evk.dts
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Ambarella CV75 EVK board
+ */
+
+/dts-v1/;
+
+#include "cv75.dtsi"
+
+/ {
+	model = "Ambarella CV75 EVK Board";
+	compatible = "ambarella,cv75-evk", "ambarella,cv75";
+
+	aliases {
+		serial0 = &uart0;
+	};
+
+	chosen {
+		stdout-path = &uart0;
+	};
+
+	memory@200000 {
+		device_type = "memory";
+		reg = <0x0 0x00200000 0x0 0x07e00000>;
+	};
+};
+
+&uart0 {
+	status = "okay";
+};
diff --git a/arch/arm64/boot/dts/ambarella/cv75.dtsi b/arch/arm64/boot/dts/ambarella/cv75.dtsi
new file mode 100644
index 000000000000..c36b6af48237
--- /dev/null
+++ b/arch/arm64/boot/dts/ambarella/cv75.dtsi
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Ambarella CV75 SoC
+ *
+ * Boot peripheral: UART0 console.
+ * Clocks: a single ambarella,cv75-rct provider.
+ */
+
+#include <dt-bindings/clock/ambarella,cv75-rct.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+/ {
+	compatible = "ambarella,cv75";
+	interrupt-parent = <&gic>;
+	#address-cells = <2>;
+	#size-cells = <2>;
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cpu@0 {
+			compatible = "arm,cortex-a76";
+			device_type = "cpu";
+			reg = <0x000>;
+			enable-method = "psci";
+		};
+
+		cpu@1 {
+			compatible = "arm,cortex-a76";
+			device_type = "cpu";
+			reg = <0x100>;
+			enable-method = "psci";
+		};
+	};
+
+	osc: oscillator {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <24000000>;
+		clock-output-names = "osc";
+	};
+
+	psci {
+		compatible = "arm,psci-0.2";
+		method = "smc";
+	};
+
+	soc {
+		compatible = "simple-bus";
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		ahb@ffe0000000 {
+			compatible = "simple-bus";
+			reg = <0xff 0xe0000000 0x0 0x01000000>;
+			ranges = <0xe0000000 0xff 0xe0000000 0x01000000>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			s_scratchpad_syscon: scratchpad@e002e000 {
+				compatible = "ambarella,cv75-sec-scratchpad", "syscon";
+				reg = <0xe002e000 0x1000>;
+			};
+		};
+
+		apb@ffe4000000 {
+			compatible = "simple-bus";
+			reg = <0xff 0xe4000000 0x0 0x01000000>;
+			ranges = <0xe4000000 0xff 0xe4000000 0x01000000>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			uart0: serial@e4000000 {
+				compatible = "ambarella,cv75-uart", "snps,dw-apb-uart";
+				reg = <0xe4000000 0x1000>;
+				clocks = <&rct CV75_GCLK_UART0>;
+				interrupts = <GIC_SPI 170 IRQ_TYPE_LEVEL_HIGH>;
+				reg-shift = <2>;
+				reg-io-width = <4>;
+				pinctrl-names = "default";
+				pinctrl-0 = <&uart0_pins>;
+
+				status = "disabled";
+			};
+
+			pinctrl: pinctrl@e4010000 {
+				compatible = "ambarella,cv75-pinctrl";
+				reg = <0xe4010000 0x1000>;
+				ambarella,drive-strength-syscon = <&rct>;
+				ambarella,pull-syscon = <&s_scratchpad_syscon>;
+
+				uart0_pins: uart0-pins {
+					function = "uart0";
+					groups = "uart0";
+				};
+			};
+
+			gpio0: gpio@e4013000 {
+				compatible = "ambarella,cv75-gpio", "arm,primecell";
+				reg = <0xe4013000 0x1000>;
+				clocks = <&rct CV75_GCLK_APB>;
+				clock-names = "apb_pclk";
+				interrupts = <GIC_SPI 163 IRQ_TYPE_LEVEL_HIGH>;
+				gpio-controller;
+				#gpio-cells = <2>;
+				gpio-ranges = <&pinctrl 0 0 32>;
+				interrupt-controller;
+				#interrupt-cells = <2>;
+				arm,primecell-periphid = <0x000e8061>;
+			};
+
+			gpio1: gpio@e4014000 {
+				compatible = "ambarella,cv75-gpio", "arm,primecell";
+				reg = <0xe4014000 0x1000>;
+				clocks = <&rct CV75_GCLK_APB>;
+				clock-names = "apb_pclk";
+				interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;
+				gpio-controller;
+				#gpio-cells = <2>;
+				gpio-ranges = <&pinctrl 0 32 32>;
+				interrupt-controller;
+				#interrupt-cells = <2>;
+				arm,primecell-periphid = <0x000e8061>;
+			};
+
+			gpio2: gpio@e4015000 {
+				compatible = "ambarella,cv75-gpio", "arm,primecell";
+				reg = <0xe4015000 0x1000>;
+				clocks = <&rct CV75_GCLK_APB>;
+				clock-names = "apb_pclk";
+				interrupts = <GIC_SPI 165 IRQ_TYPE_LEVEL_HIGH>;
+				gpio-controller;
+				#gpio-cells = <2>;
+				gpio-ranges = <&pinctrl 0 64 32>;
+				interrupt-controller;
+				#interrupt-cells = <2>;
+				arm,primecell-periphid = <0x000e8061>;
+			};
+		};
+
+		rct: clock-controller@ffed080000 {
+			compatible = "ambarella,cv75-rct", "syscon";
+			reg = <0xff 0xed080000 0x0 0x1000>;
+			clocks = <&osc>;
+			clock-names = "osc";
+			#clock-cells = <1>;
+			#reset-cells = <1>;
+			assigned-clocks = <&rct CV75_GCLK_UART0>;
+			assigned-clock-parents = <&osc>;
+			assigned-clock-rates = <24000000>;
+		};
+
+		gic: interrupt-controller@fff0101000 {
+			compatible = "arm,gic-400";
+			reg = <0xff 0xf0101000 0x0 0x1000>,
+			      <0xff 0xf0102000 0x0 0x2000>,
+			      <0xff 0xf0104000 0x0 0x2000>,
+			      <0xff 0xf0106000 0x0 0x2000>;
+			interrupt-controller;
+			#interrupt-cells = <3>;
+			#address-cells = <0>;
+			interrupts = <GIC_PPI 9
+				      (GIC_CPU_MASK_SIMPLE(2) | IRQ_TYPE_LEVEL_HIGH)>;
+		};
+	};
+
+	timer {
+		compatible = "arm,armv8-timer";
+		interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(2) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(2) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(2) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(2) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 12 (GIC_CPU_MASK_SIMPLE(2) | IRQ_TYPE_LEVEL_LOW)>;
+	};
+};
diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index ad3bd3d9507b..454f07a6a6a6 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -36,6 +36,7 @@ CONFIG_CRASH_DUMP=y
 CONFIG_ARCH_ACTIONS=y
 CONFIG_ARCH_AIROHA=y
 CONFIG_ARCH_SUNXI=y
+CONFIG_ARCH_AMBARELLA=y
 CONFIG_ARCH_ALPINE=y
 CONFIG_ARCH_APPLE=y
 CONFIG_ARCH_ARTPEC=y

-- 
2.34.1

[PATCH v11 5/5] MAINTAINERS: add ARM/AMBARELLA SoC support

[Long Zhao via B4 Relay]

From: Long Zhao <longzhao@ambarella.com>

Add a maintainer entry covering Ambarella CV75 bindings, DTS and
related drivers.

Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Long Zhao <longzhao@ambarella.com>
---
 MAINTAINERS | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 803b60ad628f..59e5b32d7a02 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2502,6 +2502,20 @@ F:	drivers/clocksource/asm9260_timer.c
 F:	drivers/rtc/rtc-asm9260.c
 F:	drivers/watchdog/asm9260_wdt.c
 
+ARM/AMBARELLA SOC SUPPORT
+M:	Long Zhao <longzhao@ambarella.com>
+L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
+L:	devicetree@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/arm/ambarella.yaml
+F:	Documentation/devicetree/bindings/clock/ambarella,cv75-rct.yaml
+F:	Documentation/devicetree/bindings/pinctrl/ambarella,cv75-pinctrl.yaml
+F:	arch/arm64/boot/dts/ambarella/
+F:	drivers/clk/ambarella/
+F:	drivers/pinctrl/pinctrl-ambarella*
+F:	include/dt-bindings/clock/ambarella,cv75-rct.h
+N:	ambarella
+
 ARM/AMD PENSANDO ARM64 ARCHITECTURE
 M:	Brad Larson <blarson@amd.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)

-- 
2.34.1

Re: [PATCH v11 4/5] arm64: ambarella: add ARCH_AMBARELLA and CV75 EVK DT

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 5 potential issue(s) to consider:
- [High] arm64: dts: ambarella: uart0 permanently defers probe due to missing pinctrl
- [Medium] arm64: dts: ambarella: undocumented compatible strings and properties in cv75
- [Medium] arm64: dts: ambarella: gpio nodes use unmatched periphid and unprobed pinctrl
- [Medium] arm64: dts: ambarella: apb simple-bus reg blocks child AMBA gpio registration
- [Low] arm64: dts: ambarella: cpu@1 unit-address mismatches reg value 0x100 in cv75
--

commit 2577b890c9c87bc36cb977c573e3558792596572
Author: Long Zhao <longzhao@ambarella.com>

arm64: ambarella: add ARCH_AMBARELLA and CV75 EVK DT

This commit enables ARCH_AMBARELLA and adds a minimal device tree for the
Ambarella CV75 SoC and EVK board with RCT clocks, UART, pinctrl, and GPIO
banks.

> diff --git a/arch/arm64/boot/dts/ambarella/cv75.dtsi b/arch/arm64/boot/dts/ambarella/cv75.dtsi
> new file mode 100644
> index 0000000000000..c36b6af48237a
> --- /dev/null
> +++ b/arch/arm64/boot/dts/ambarella/cv75.dtsi
> @@ -0,0 +1,177 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Ambarella CV75 SoC
> + *
> + * Boot peripheral: UART0 console.
> + * Clocks: a single ambarella,cv75-rct provider.
> + */
> +
> +#include <dt-bindings/clock/ambarella,cv75-rct.h>
> +#include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> +/ {
> +	compatible = "ambarella,cv75";
> +	interrupt-parent = <&gic>;
> +	#address-cells = <2>;
> +	#size-cells = <2>;
> +
> +	cpus {
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		cpu@0 {
> +			compatible = "arm,cortex-a76";
> +			device_type = "cpu";
> +			reg = <0x000>;
> +			enable-method = "psci";
> +		};
> +
> +		cpu@1 {
> +			compatible = "arm,cortex-a76";
> +			device_type = "cpu";
> +			reg = <0x100>;
> +			enable-method = "psci";
> +		};

[Severity: Low]
In arch/arm64/boot/dts/ambarella/cv75.dtsi, the second CPU node is named
cpu@1 while its reg property is <0x100>. Does this trigger a
unit_address_vs_reg warning during W=1 builds and dtbs_check? Should the
node unit-address match the reg property as cpu@100 (or reg = <0x1> if
MPIDR Aff0 is 1)?

[ ... ]

> +	soc {
> +		compatible = "simple-bus";
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +		ranges;
> +
> +		ahb@ffe0000000 {
> +			compatible = "simple-bus";
> +			reg = <0xff 0xe0000000 0x0 0x01000000>;
> +			ranges = <0xe0000000 0xff 0xe0000000 0x01000000>;
> +			#address-cells = <1>;
> +			#size-cells = <1>;
> +
> +			s_scratchpad_syscon: scratchpad@e002e000 {
> +				compatible = "ambarella,cv75-sec-scratchpad", "syscon";
> +				reg = <0xe002e000 0x1000>;
> +			};
> +		};
> +
> +		apb@ffe4000000 {
> +			compatible = "simple-bus";
> +			reg = <0xff 0xe4000000 0x0 0x01000000>;
> +			ranges = <0xe4000000 0xff 0xe4000000 0x01000000>;
> +			#address-cells = <1>;
> +			#size-cells = <1>;

[Severity: Medium]
Does specifying reg = <0xff 0xe4000000 0x0 0x01000000> on the
apb@ffe4000000 simple-bus node block registration of the child AMBA GPIO
devices (gpio0, gpio1, and gpio2) with -EBUSY?

During of_platform_default_populate(), of_platform_bus_create() creates a
platform_device for apb@ffe4000000, and platform_device_add() calls
insert_resource(&iomem_resource, r), reserving [mem 0xffe4000000-0xffe4ffffff]
as a top-level child of iomem_resource.

When of_platform_bus_create() then iterates over the child "arm,primecell"
nodes (gpio@e4013000, gpio@e4014000, and gpio@e4015000), it calls:

of_amba_device_create()
  amba_device_add(dev, &iomem_resource)
    request_resource(&iomem_resource, &dev->res)

Because __request_resource() checks direct children of iomem_resource, it
collides with the parent bus reservation and returns -EBUSY, causing
amba_device_add() to fail for each GPIO controller.

> +
> +			uart0: serial@e4000000 {
> +				compatible = "ambarella,cv75-uart", "snps,dw-apb-uart";
> +				reg = <0xe4000000 0x1000>;
> +				clocks = <&rct CV75_GCLK_UART0>;
> +				interrupts = <GIC_SPI 170 IRQ_TYPE_LEVEL_HIGH>;
> +				reg-shift = <2>;
> +				reg-io-width = <4>;
> +				pinctrl-names = "default";
> +				pinctrl-0 = <&uart0_pins>;
> +
> +				status = "disabled";
> +			};
> +
> +			pinctrl: pinctrl@e4010000 {
> +				compatible = "ambarella,cv75-pinctrl";
> +				reg = <0xe4010000 0x1000>;
> +				ambarella,drive-strength-syscon = <&rct>;
> +				ambarella,pull-syscon = <&s_scratchpad_syscon>;
> +
> +				uart0_pins: uart0-pins {
> +					function = "uart0";
> +					groups = "uart0";
> +				};
> +			};

[Severity: High]
As reported by Sashiko on v10 [1], will uart0 (enabled as stdout-path in
arch/arm64/boot/dts/ambarella/cv75-evk.dts) permanently defer probing with
-EPROBE_DEFER because no driver exists for "ambarella,cv75-pinctrl"?

In arch/arm64/Kconfig.platforms, ARCH_AMBARELLA selects PINCTRL, and the
arm64 defconfig enables both CONFIG_ARCH_AMBARELLA=y and CONFIG_MODULES=y.
Because uart0 declares pinctrl-0 = <&uart0_pins> referencing
pinctrl@e4010000, fw_devlink (parse_pinctrl_n() ->
device_links_check_suppliers()) blocks uart0 waiting for the pinctrl
supplier.

Even if fw_devlink times out or is disabled, really_probe() calls:

pinctrl_bind_pins()
  devm_pinctrl_get()
    create_pinctrl()
      pinctrl_dt_to_map()
        dt_to_map_one_config()

In drivers/pinctrl/devicetree.c:dt_to_map_one_config(), when
get_pinctrl_dev_from_of_node() finds no registered pinctrl_dev for
pinctrl@e4010000 and walks up to the root node without pinctrl-use-default:

		if (!np_pctldev || of_node_is_root(np_pctldev)) {
			of_node_put(np_pctldev);
			ret = -ENODEV;
			/* keep deferring if modules are enabled */
			if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret < 0)
				ret = -EPROBE_DEFER;
			return ret;
		}

This returns -EPROBE_DEFER whenever CONFIG_MODULES is enabled, preventing
dw8250_probe() from ever binding the serial console.

> +
> +			gpio0: gpio@e4013000 {
> +				compatible = "ambarella,cv75-gpio", "arm,primecell";
> +				reg = <0xe4013000 0x1000>;
> +				clocks = <&rct CV75_GCLK_APB>;
> +				clock-names = "apb_pclk";
> +				interrupts = <GIC_SPI 163 IRQ_TYPE_LEVEL_HIGH>;
> +				gpio-controller;
> +				#gpio-cells = <2>;
> +				gpio-ranges = <&pinctrl 0 0 32>;
> +				interrupt-controller;
> +				#interrupt-cells = <2>;
> +				arm,primecell-periphid = <0x000e8061>;
> +			};

[Severity: Medium]
As reported by Sashiko on v10 [1], can gpio0, gpio1, and gpio2 bind to any
driver in the kernel tree?

Because "arm,primecell" is in compatible, of_platform_bus_create()
instantiates these nodes as struct amba_device objects with periphid
0x000e8061. In drivers/amba/bus.c, amba_match() matches AMBA devices solely
against pcdrv->id_table via amba_lookup(). However, drivers/gpio/gpio-pl061.c
only matches periphid 0x00041061 (and supports 8 lines per block rather than
32):

static const struct amba_id pl061_ids[] = {
	{
		.id	= 0x00041061,
		.mask	= 0x000fffff,
	},
	{ 0, 0 },
};

In addition, each GPIO node specifies gpio-ranges referencing &pinctrl
("ambarella,cv75-pinctrl"), which has no driver in the tree, so
of_gpiochip_add_pin_range() would also defer probing with -EPROBE_DEFER when
of_pinctrl_get() fails to find a registered pinctrl device.

[Severity: Medium]
As reported by Sashiko on v10 [1], does make dtbs_check fail on
cv75-evk.dtb due to undocumented compatible strings and properties in
arch/arm64/boot/dts/ambarella/cv75.dtsi?

Specifically, there do not appear to be Devicetree binding schemas covering:
- "ambarella,cv75-sec-scratchpad" in scratchpad@e002e000 (not in
  Documentation/devicetree/bindings/mfd/syscon.yaml)
- "ambarella,cv75-uart" in serial@e4000000 (not in
  Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml)
- "ambarella,cv75-pinctrl", ambarella,drive-strength-syscon, and
  ambarella,pull-syscon in pinctrl@e4010000
- "ambarella,cv75-gpio" in gpio@e4013000, gpio@e4014000, and gpio@e4015000
- the reg properties on the simple-bus nodes ahb@ffe0000000 and
  apb@ffe4000000

[1] https://lore.kernel.org/r/20261019-cv75-soc-v10-4-d386065e2dd5@ambarella.com

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261105-cv75-soc-v11-0-aa6ee0b2380d@ambarella.com?part=4