[PATCH v4 0/2] m68k: coldfire: Add RNG support for MCF54418

[PATCH v4 0/2] m68k: coldfire: Add RNG support for MCF54418

[Jean-Michel Hautbois via B4 Relay]

This series adds support for the MCF54418 hardware random number generator
(RNGB).

The MCF54418 contains an RNGB hardware block compatible with the imx-rngc
driver. This series enables its use by:
- Adding platform device registration for the RNG hardware
- Enabling the clock at platform initialization
- Making the imx-rngc driver compatible with Coldfire's always-on clock
model using devm_clk_get_optional()

Testing on DLC Next board shows:
- Hardware RNG throughput: 26 MB/s
- FIPS 140-2 quality: 0.2% failure rate (rng-tools)
- Boot time improvement: CRNG initialization 7 seconds faster

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
---
Changes in v4:
- Postpone const qualifiers for now
- Link to v3: https://lore.kernel.org/r/20251124-b4-m5441x-add-rng-support-v3-0-f447251dad27@yoseli.org

Changes in v3:
- Depend on COLDFIRE is enough
- Split the clock change in a dedicated commit
- Link to v2: https://lore.kernel.org/r/20251107-b4-m5441x-add-rng-support-v2-0-f91d685832b9@yoseli.org

Changes in v2:
- Split const qualifier changes into a separate patch as suggested by
Frank Li
- Mark all resource arrays (including RNG) as const in device.c
- No functional changes to RNG implementation

---
Jean-Michel Hautbois (2):
      hwrng: imx-rngc: Use optional clock
      m68k: coldfire: Add RNG support for MCF54418

 arch/m68k/coldfire/device.c       | 28 ++++++++++++++++++++++++++++
 arch/m68k/coldfire/m5441x.c       |  2 +-
 arch/m68k/include/asm/m5441xsim.h |  9 +++++++++
 drivers/char/hw_random/Kconfig    |  3 ++-
 drivers/char/hw_random/imx-rngc.c |  9 ++++++++-
 5 files changed, 48 insertions(+), 3 deletions(-)
---
base-commit: ac3fd01e4c1efce8f2c054cdeb2ddd2fc0fb150d
change-id: 20251107-b4-m5441x-add-rng-support-0fdb8d40210a

Best regards,
--  
Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>

[PATCH v4 1/2] hwrng: imx-rngc: Use optional clock

[Jean-Michel Hautbois via B4 Relay]

From: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>

Change devm_clk_get() to devm_clk_get_optional() to support platforms
where the RNG clock is always enabled and not exposed via the clock
framework (such as ColdFire MCF54418).

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
---
 drivers/char/hw_random/imx-rngc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c
index 241664a9b5d9..d6a847e48339 100644
--- a/drivers/char/hw_random/imx-rngc.c
+++ b/drivers/char/hw_random/imx-rngc.c
@@ -259,7 +259,7 @@ static int __init imx_rngc_probe(struct platform_device *pdev)
 	if (IS_ERR(rngc->base))
 		return PTR_ERR(rngc->base);
 
-	rngc->clk = devm_clk_get(&pdev->dev, NULL);
+	rngc->clk = devm_clk_get_optional(&pdev->dev, NULL);
 	if (IS_ERR(rngc->clk))
 		return dev_err_probe(&pdev->dev, PTR_ERR(rngc->clk), "Cannot get rng_clk\n");
 

-- 
2.39.5

[PATCH v4 2/2] m68k: coldfire: Add RNG support for MCF54418

[Jean-Michel Hautbois via B4 Relay]

From: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>

Add support for the hardware Random Number Generator (RNGB) found on
MCF54418 ColdFire processors with clock enabled at platform
initialization.

The RNGB block is compatible with the imx-rngc driver.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
---
 arch/m68k/coldfire/device.c       | 28 ++++++++++++++++++++++++++++
 arch/m68k/coldfire/m5441x.c       |  2 +-
 arch/m68k/include/asm/m5441xsim.h |  9 +++++++++
 drivers/char/hw_random/Kconfig    |  3 ++-
 drivers/char/hw_random/imx-rngc.c |  7 +++++++
 5 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/arch/m68k/coldfire/device.c b/arch/m68k/coldfire/device.c
index b6958ec2a220..9d8f844e319a 100644
--- a/arch/m68k/coldfire/device.c
+++ b/arch/m68k/coldfire/device.c
@@ -622,6 +622,31 @@ static struct platform_device mcf_flexcan0 = {
 };
 #endif /* MCFFLEXCAN_SIZE */
 
+#ifdef MCF_RNG_BASE
+/*
+ * Random Number Generator (RNG) - only on MCF54418
+ */
+static struct resource mcf_rng_resource[] = {
+	{
+		.start = MCF_RNG_BASE,
+		.end   = MCF_RNG_BASE + MCF_RNG_SIZE - 1,
+		.flags = IORESOURCE_MEM,
+	},
+	{
+		.start = MCF_IRQ_RNG,
+		.end   = MCF_IRQ_RNG,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct platform_device mcf_rng = {
+	.name           = "imx-rngc",
+	.id             = -1,
+	.num_resources  = ARRAY_SIZE(mcf_rng_resource),
+	.resource       = mcf_rng_resource,
+};
+#endif /* MCF_RNG_BASE */
+
 static struct platform_device *mcf_devices[] __initdata = {
 	&mcf_uart,
 #ifdef MCFFEC_BASE0
@@ -660,6 +685,9 @@ static struct platform_device *mcf_devices[] __initdata = {
 #ifdef MCFFLEXCAN_SIZE
 	&mcf_flexcan0,
 #endif
+#ifdef MCF_RNG_BASE
+	&mcf_rng,
+#endif
 };
 
 /*
diff --git a/arch/m68k/coldfire/m5441x.c b/arch/m68k/coldfire/m5441x.c
index 7a25cfc7ac07..ab5b00637237 100644
--- a/arch/m68k/coldfire/m5441x.c
+++ b/arch/m68k/coldfire/m5441x.c
@@ -158,6 +158,7 @@ static struct clk * const enable_clks[] __initconst = {
 	&__clk_0_33, /* pit.1 */
 	&__clk_0_37, /* eport */
 	&__clk_0_48, /* pll */
+	&__clk_0_49, /* rng */
 	&__clk_0_51, /* esdhc */
 
 	&__clk_1_36, /* CCM/reset module/Power management */
@@ -179,7 +180,6 @@ static struct clk * const disable_clks[] __initconst = {
 	&__clk_0_44, /* usb otg */
 	&__clk_0_45, /* usb host */
 	&__clk_0_47, /* ssi.0 */
-	&__clk_0_49, /* rng */
 	&__clk_0_50, /* ssi.1 */
 	&__clk_0_53, /* enet-fec */
 	&__clk_0_54, /* enet-fec */
diff --git a/arch/m68k/include/asm/m5441xsim.h b/arch/m68k/include/asm/m5441xsim.h
index f48cf63bd782..dd64cdfcad3e 100644
--- a/arch/m68k/include/asm/m5441xsim.h
+++ b/arch/m68k/include/asm/m5441xsim.h
@@ -198,6 +198,15 @@
 #define MCFRTC_SIZE		(0xfc0a8840 - 0xfc0a8000)
 #define MCF_IRQ_RTC		(MCFINT2_VECBASE + MCFINT2_RTC)
 
+/*
+ *  Random Number Generator (RNG) Module.
+ *  Note: Only present in MCF54418, not in MCF54410/54415/54417
+ */
+#define MCF_RNG_BASE		0xfc0c4000
+#define MCF_RNG_SIZE		0x1c
+#define MCFINT2_RNG		28
+#define MCF_IRQ_RNG		(MCFINT2_VECBASE + MCFINT2_RNG)
+
 /*
  *  GPIO Module.
  */
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 492a2a61a65b..2f301e43db84 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -270,12 +270,13 @@ config HW_RANDOM_MXC_RNGA
 config HW_RANDOM_IMX_RNGC
 	tristate "Freescale i.MX RNGC Random Number Generator"
 	depends on HAS_IOMEM
-	depends on SOC_IMX25 || SOC_IMX6SL || SOC_IMX6SLL || SOC_IMX6UL || COMPILE_TEST
+	depends on SOC_IMX25 || SOC_IMX6SL || SOC_IMX6SLL || SOC_IMX6UL || COLDFIRE || COMPILE_TEST
 	default HW_RANDOM
 	help
 	  This driver provides kernel-side support for the Random Number
 	  Generator Version C hardware found on some Freescale i.MX
 	  processors. Version B is also supported by this driver.
+	  Also supports RNGB on Freescale MCF54418 (Coldfire V4e).
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called imx-rngc.
diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c
index d6a847e48339..44f20a05de0a 100644
--- a/drivers/char/hw_random/imx-rngc.c
+++ b/drivers/char/hw_random/imx-rngc.c
@@ -353,12 +353,19 @@ static const struct of_device_id imx_rngc_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, imx_rngc_dt_ids);
 
+static const struct platform_device_id imx_rngc_devtype[] = {
+	{ .name = "imx-rngc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, imx_rngc_devtype);
+
 static struct platform_driver imx_rngc_driver = {
 	.driver = {
 		.name = KBUILD_MODNAME,
 		.pm = pm_ptr(&imx_rngc_pm_ops),
 		.of_match_table = imx_rngc_dt_ids,
 	},
+	.id_table = imx_rngc_devtype,
 };
 
 module_platform_driver_probe(imx_rngc_driver, imx_rngc_probe);

-- 
2.39.5

Re: [PATCH v4 1/2] hwrng: imx-rngc: Use optional clock

[Martin Kaiser]

Thus wrote Jean-Michel Hautbois via B4 Relay (devnull+jeanmichel.hautbois.yoseli.org@kernel.org):

> From: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>

> Change devm_clk_get() to devm_clk_get_optional() to support platforms
> where the RNG clock is always enabled and not exposed via the clock
> framework (such as ColdFire MCF54418).

> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> ---
>  drivers/char/hw_random/imx-rngc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

> diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c
> index 241664a9b5d9..d6a847e48339 100644
> --- a/drivers/char/hw_random/imx-rngc.c
> +++ b/drivers/char/hw_random/imx-rngc.c
> @@ -259,7 +259,7 @@ static int __init imx_rngc_probe(struct platform_device *pdev)
>  	if (IS_ERR(rngc->base))
>  		return PTR_ERR(rngc->base);

> -	rngc->clk = devm_clk_get(&pdev->dev, NULL);
> +	rngc->clk = devm_clk_get_optional(&pdev->dev, NULL);
>  	if (IS_ERR(rngc->clk))
>  		return dev_err_probe(&pdev->dev, PTR_ERR(rngc->clk), "Cannot get rng_clk\n");

The clock is not optional on a standard imx25 system. If it's missing in the
device tree, the rngb will not work and we should not load the driver.

Should we call devm_clk_get or devm_clk_get_optional, depending on the
detected device?

Best regards,
Martin

Re: [PATCH v4 1/2] hwrng: imx-rngc: Use optional clock

[Geert Uytterhoeven]

Hi Martin,

On Wed, 26 Nov 2025 at 21:30, Martin Kaiser <martin@kaiser.cx> wrote:
> Thus wrote Jean-Michel Hautbois via B4 Relay (devnull+jeanmichel.hautbois.yoseli.org@kernel.org):
>
> > From: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
>
> > Change devm_clk_get() to devm_clk_get_optional() to support platforms
> > where the RNG clock is always enabled and not exposed via the clock
> > framework (such as ColdFire MCF54418).
>
> > Reviewed-by: Frank Li <Frank.Li@nxp.com>
> > Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> > ---
> >  drivers/char/hw_random/imx-rngc.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
>
> > diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c
> > index 241664a9b5d9..d6a847e48339 100644
> > --- a/drivers/char/hw_random/imx-rngc.c
> > +++ b/drivers/char/hw_random/imx-rngc.c
> > @@ -259,7 +259,7 @@ static int __init imx_rngc_probe(struct platform_device *pdev)
> >       if (IS_ERR(rngc->base))
> >               return PTR_ERR(rngc->base);
>
> > -     rngc->clk = devm_clk_get(&pdev->dev, NULL);
> > +     rngc->clk = devm_clk_get_optional(&pdev->dev, NULL);
> >       if (IS_ERR(rngc->clk))
> >               return dev_err_probe(&pdev->dev, PTR_ERR(rngc->clk), "Cannot get rng_clk\n");
>
> The clock is not optional on a standard imx25 system. If it's missing in the
> device tree, the rngb will not work and we should not load the driver.

As the clocks property is marked required in
Documentation/devicetree/bindings/rng/imx-rng.yaml, "make dtbs_check"
should flag a missing clock.

> Should we call devm_clk_get or devm_clk_get_optional, depending on the
> detected device?

That can quickly lead to complex code.  Nowadays it is fine to rely on
"make dtbs_check" for some part of the validation.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v4 1/2] hwrng: imx-rngc: Use optional clock

[Martin Kaiser]

Hi Geert,

Thus wrote Geert Uytterhoeven (geert@linux-m68k.org):

> Hi Martin,

> On Wed, 26 Nov 2025 at 21:30, Martin Kaiser <martin@kaiser.cx> wrote:
> > Thus wrote Jean-Michel Hautbois via B4 Relay (devnull+jeanmichel.hautbois.yoseli.org@kernel.org):

> > > From: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>

> > > Change devm_clk_get() to devm_clk_get_optional() to support platforms
> > > where the RNG clock is always enabled and not exposed via the clock
> > > framework (such as ColdFire MCF54418).

> > > Reviewed-by: Frank Li <Frank.Li@nxp.com>
> > > Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> > > ---
> > >  drivers/char/hw_random/imx-rngc.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)

> > > diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c
> > > index 241664a9b5d9..d6a847e48339 100644
> > > --- a/drivers/char/hw_random/imx-rngc.c
> > > +++ b/drivers/char/hw_random/imx-rngc.c
> > > @@ -259,7 +259,7 @@ static int __init imx_rngc_probe(struct platform_device *pdev)
> > >       if (IS_ERR(rngc->base))
> > >               return PTR_ERR(rngc->base);

> > > -     rngc->clk = devm_clk_get(&pdev->dev, NULL);
> > > +     rngc->clk = devm_clk_get_optional(&pdev->dev, NULL);
> > >       if (IS_ERR(rngc->clk))
> > >               return dev_err_probe(&pdev->dev, PTR_ERR(rngc->clk), "Cannot get rng_clk\n");

> > The clock is not optional on a standard imx25 system. If it's missing in the
> > device tree, the rngb will not work and we should not load the driver.

> As the clocks property is marked required in
> Documentation/devicetree/bindings/rng/imx-rng.yaml, "make dtbs_check"
> should flag a missing clock.

> > Should we call devm_clk_get or devm_clk_get_optional, depending on the
> > detected device?

> That can quickly lead to complex code.  Nowadays it is fine to rely on
> "make dtbs_check" for some part of the validation.

ok, understood. With this clarification, I'm happy with the patch.

Reviewed-by: Martin Kaiser <martin@kaiser.cx>

Thanks,
Martin

Re: [PATCH v4 2/2] m68k: coldfire: Add RNG support for MCF54418

[Greg Ungerer]

Hi Jean-Michel,

On 26/11/25 17:08, Jean-Michel Hautbois via B4 Relay wrote:
> From: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> 
> Add support for the hardware Random Number Generator (RNGB) found on
> MCF54418 ColdFire processors with clock enabled at platform
> initialization.
> 
> The RNGB block is compatible with the imx-rngc driver.
> 
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> ---
>   arch/m68k/coldfire/device.c       | 28 ++++++++++++++++++++++++++++
>   arch/m68k/coldfire/m5441x.c       |  2 +-
>   arch/m68k/include/asm/m5441xsim.h |  9 +++++++++
>   drivers/char/hw_random/Kconfig    |  3 ++-
>   drivers/char/hw_random/imx-rngc.c |  7 +++++++
>   5 files changed, 47 insertions(+), 2 deletions(-)

I am happy with the ColdFire arch parts, so from me:

     Acked-by: Greg Ungerer <gerg@linux-m68k.org>

I don't mind taking this commit via the m68knommu git tree if the hw_rng
maintainers are ok with that. Otherwise if you break out the arch/m68k
parts I can apply those on their own.

Regards
Greg



> diff --git a/arch/m68k/coldfire/device.c b/arch/m68k/coldfire/device.c
> index b6958ec2a220..9d8f844e319a 100644
> --- a/arch/m68k/coldfire/device.c
> +++ b/arch/m68k/coldfire/device.c
> @@ -622,6 +622,31 @@ static struct platform_device mcf_flexcan0 = {
>   };
>   #endif /* MCFFLEXCAN_SIZE */
>   
> +#ifdef MCF_RNG_BASE
> +/*
> + * Random Number Generator (RNG) - only on MCF54418
> + */
> +static struct resource mcf_rng_resource[] = {
> +	{
> +		.start = MCF_RNG_BASE,
> +		.end   = MCF_RNG_BASE + MCF_RNG_SIZE - 1,
> +		.flags = IORESOURCE_MEM,
> +	},
> +	{
> +		.start = MCF_IRQ_RNG,
> +		.end   = MCF_IRQ_RNG,
> +		.flags = IORESOURCE_IRQ,
> +	},
> +};
> +
> +static struct platform_device mcf_rng = {
> +	.name           = "imx-rngc",
> +	.id             = -1,
> +	.num_resources  = ARRAY_SIZE(mcf_rng_resource),
> +	.resource       = mcf_rng_resource,
> +};
> +#endif /* MCF_RNG_BASE */
> +
>   static struct platform_device *mcf_devices[] __initdata = {
>   	&mcf_uart,
>   #ifdef MCFFEC_BASE0
> @@ -660,6 +685,9 @@ static struct platform_device *mcf_devices[] __initdata = {
>   #ifdef MCFFLEXCAN_SIZE
>   	&mcf_flexcan0,
>   #endif
> +#ifdef MCF_RNG_BASE
> +	&mcf_rng,
> +#endif
>   };
>   
>   /*
> diff --git a/arch/m68k/coldfire/m5441x.c b/arch/m68k/coldfire/m5441x.c
> index 7a25cfc7ac07..ab5b00637237 100644
> --- a/arch/m68k/coldfire/m5441x.c
> +++ b/arch/m68k/coldfire/m5441x.c
> @@ -158,6 +158,7 @@ static struct clk * const enable_clks[] __initconst = {
>   	&__clk_0_33, /* pit.1 */
>   	&__clk_0_37, /* eport */
>   	&__clk_0_48, /* pll */
> +	&__clk_0_49, /* rng */
>   	&__clk_0_51, /* esdhc */
>   
>   	&__clk_1_36, /* CCM/reset module/Power management */
> @@ -179,7 +180,6 @@ static struct clk * const disable_clks[] __initconst = {
>   	&__clk_0_44, /* usb otg */
>   	&__clk_0_45, /* usb host */
>   	&__clk_0_47, /* ssi.0 */
> -	&__clk_0_49, /* rng */
>   	&__clk_0_50, /* ssi.1 */
>   	&__clk_0_53, /* enet-fec */
>   	&__clk_0_54, /* enet-fec */
> diff --git a/arch/m68k/include/asm/m5441xsim.h b/arch/m68k/include/asm/m5441xsim.h
> index f48cf63bd782..dd64cdfcad3e 100644
> --- a/arch/m68k/include/asm/m5441xsim.h
> +++ b/arch/m68k/include/asm/m5441xsim.h
> @@ -198,6 +198,15 @@
>   #define MCFRTC_SIZE		(0xfc0a8840 - 0xfc0a8000)
>   #define MCF_IRQ_RTC		(MCFINT2_VECBASE + MCFINT2_RTC)
>   
> +/*
> + *  Random Number Generator (RNG) Module.
> + *  Note: Only present in MCF54418, not in MCF54410/54415/54417
> + */
> +#define MCF_RNG_BASE		0xfc0c4000
> +#define MCF_RNG_SIZE		0x1c
> +#define MCFINT2_RNG		28
> +#define MCF_IRQ_RNG		(MCFINT2_VECBASE + MCFINT2_RNG)
> +
>   /*
>    *  GPIO Module.
>    */
> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
> index 492a2a61a65b..2f301e43db84 100644
> --- a/drivers/char/hw_random/Kconfig
> +++ b/drivers/char/hw_random/Kconfig
> @@ -270,12 +270,13 @@ config HW_RANDOM_MXC_RNGA
>   config HW_RANDOM_IMX_RNGC
>   	tristate "Freescale i.MX RNGC Random Number Generator"
>   	depends on HAS_IOMEM
> -	depends on SOC_IMX25 || SOC_IMX6SL || SOC_IMX6SLL || SOC_IMX6UL || COMPILE_TEST
> +	depends on SOC_IMX25 || SOC_IMX6SL || SOC_IMX6SLL || SOC_IMX6UL || COLDFIRE || COMPILE_TEST
>   	default HW_RANDOM
>   	help
>   	  This driver provides kernel-side support for the Random Number
>   	  Generator Version C hardware found on some Freescale i.MX
>   	  processors. Version B is also supported by this driver.
> +	  Also supports RNGB on Freescale MCF54418 (Coldfire V4e).
>   
>   	  To compile this driver as a module, choose M here: the
>   	  module will be called imx-rngc.
> diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c
> index d6a847e48339..44f20a05de0a 100644
> --- a/drivers/char/hw_random/imx-rngc.c
> +++ b/drivers/char/hw_random/imx-rngc.c
> @@ -353,12 +353,19 @@ static const struct of_device_id imx_rngc_dt_ids[] = {
>   };
>   MODULE_DEVICE_TABLE(of, imx_rngc_dt_ids);
>   
> +static const struct platform_device_id imx_rngc_devtype[] = {
> +	{ .name = "imx-rngc" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(platform, imx_rngc_devtype);
> +
>   static struct platform_driver imx_rngc_driver = {
>   	.driver = {
>   		.name = KBUILD_MODNAME,
>   		.pm = pm_ptr(&imx_rngc_pm_ops),
>   		.of_match_table = imx_rngc_dt_ids,
>   	},
> +	.id_table = imx_rngc_devtype,
>   };
>   
>   module_platform_driver_probe(imx_rngc_driver, imx_rngc_probe);
> 

Re: [PATCH v4 1/2] hwrng: imx-rngc: Use optional clock

[Herbert Xu]

On Wed, Nov 26, 2025 at 08:08:09AM +0100, Jean-Michel Hautbois via B4 Relay wrote:
> From: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> 
> Change devm_clk_get() to devm_clk_get_optional() to support platforms
> where the RNG clock is always enabled and not exposed via the clock
> framework (such as ColdFire MCF54418).
> 
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> ---
>  drivers/char/hw_random/imx-rngc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH v4 2/2] m68k: coldfire: Add RNG support for MCF54418

[Herbert Xu]

On Wed, Nov 26, 2025 at 08:08:10AM +0100, Jean-Michel Hautbois via B4 Relay wrote:
> From: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> 
> Add support for the hardware Random Number Generator (RNGB) found on
> MCF54418 ColdFire processors with clock enabled at platform
> initialization.
> 
> The RNGB block is compatible with the imx-rngc driver.
> 
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> ---
>  arch/m68k/coldfire/device.c       | 28 ++++++++++++++++++++++++++++
>  arch/m68k/coldfire/m5441x.c       |  2 +-
>  arch/m68k/include/asm/m5441xsim.h |  9 +++++++++
>  drivers/char/hw_random/Kconfig    |  3 ++-
>  drivers/char/hw_random/imx-rngc.c |  7 +++++++
>  5 files changed, 47 insertions(+), 2 deletions(-)

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH v4 2/2] m68k: coldfire: Add RNG support for MCF54418

[Jean-Michel Hautbois]

Hi Greg,

Sorry for the very long silence on this one, it fell off my radar...

Le 03/12/2025 à 13:15, Greg Ungerer a écrit :
> Hi Jean-Michel,
> 
> On 26/11/25 17:08, Jean-Michel Hautbois via B4 Relay wrote:
>> From: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
>>
>> Add support for the hardware Random Number Generator (RNGB) found on
>> MCF54418 ColdFire processors with clock enabled at platform
>> initialization.
>>
>> The RNGB block is compatible with the imx-rngc driver.
>>
>> Reviewed-by: Frank Li <Frank.Li@nxp.com>
>> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
>> ---
>>   arch/m68k/coldfire/device.c       | 28 ++++++++++++++++++++++++++++
>>   arch/m68k/coldfire/m5441x.c       |  2 +-
>>   arch/m68k/include/asm/m5441xsim.h |  9 +++++++++
>>   drivers/char/hw_random/Kconfig    |  3 ++-
>>   drivers/char/hw_random/imx-rngc.c |  7 +++++++
>>   5 files changed, 47 insertions(+), 2 deletions(-)
> 
> I am happy with the ColdFire arch parts, so from me:
> 
>      Acked-by: Greg Ungerer <gerg@linux-m68k.org>
> 
> I don't mind taking this commit via the m68knommu git tree if the hw_rng
> maintainers are ok with that. Otherwise if you break out the arch/m68k
> parts I can apply those on their own.

I think Herbert acked ?
Do you need another ack ?

Thanks !
JM

> Regards
> Greg
> 
> 
> 
>> diff --git a/arch/m68k/coldfire/device.c b/arch/m68k/coldfire/device.c
>> index b6958ec2a220..9d8f844e319a 100644
>> --- a/arch/m68k/coldfire/device.c
>> +++ b/arch/m68k/coldfire/device.c
>> @@ -622,6 +622,31 @@ static struct platform_device mcf_flexcan0 = {
>>   };
>>   #endif /* MCFFLEXCAN_SIZE */
>> +#ifdef MCF_RNG_BASE
>> +/*
>> + * Random Number Generator (RNG) - only on MCF54418
>> + */
>> +static struct resource mcf_rng_resource[] = {
>> +    {
>> +        .start = MCF_RNG_BASE,
>> +        .end   = MCF_RNG_BASE + MCF_RNG_SIZE - 1,
>> +        .flags = IORESOURCE_MEM,
>> +    },
>> +    {
>> +        .start = MCF_IRQ_RNG,
>> +        .end   = MCF_IRQ_RNG,
>> +        .flags = IORESOURCE_IRQ,
>> +    },
>> +};
>> +
>> +static struct platform_device mcf_rng = {
>> +    .name           = "imx-rngc",
>> +    .id             = -1,
>> +    .num_resources  = ARRAY_SIZE(mcf_rng_resource),
>> +    .resource       = mcf_rng_resource,
>> +};
>> +#endif /* MCF_RNG_BASE */
>> +
>>   static struct platform_device *mcf_devices[] __initdata = {
>>       &mcf_uart,
>>   #ifdef MCFFEC_BASE0
>> @@ -660,6 +685,9 @@ static struct platform_device *mcf_devices[] 
>> __initdata = {
>>   #ifdef MCFFLEXCAN_SIZE
>>       &mcf_flexcan0,
>>   #endif
>> +#ifdef MCF_RNG_BASE
>> +    &mcf_rng,
>> +#endif
>>   };
>>   /*
>> diff --git a/arch/m68k/coldfire/m5441x.c b/arch/m68k/coldfire/m5441x.c
>> index 7a25cfc7ac07..ab5b00637237 100644
>> --- a/arch/m68k/coldfire/m5441x.c
>> +++ b/arch/m68k/coldfire/m5441x.c
>> @@ -158,6 +158,7 @@ static struct clk * const enable_clks[] 
>> __initconst = {
>>       &__clk_0_33, /* pit.1 */
>>       &__clk_0_37, /* eport */
>>       &__clk_0_48, /* pll */
>> +    &__clk_0_49, /* rng */
>>       &__clk_0_51, /* esdhc */
>>       &__clk_1_36, /* CCM/reset module/Power management */
>> @@ -179,7 +180,6 @@ static struct clk * const disable_clks[] 
>> __initconst = {
>>       &__clk_0_44, /* usb otg */
>>       &__clk_0_45, /* usb host */
>>       &__clk_0_47, /* ssi.0 */
>> -    &__clk_0_49, /* rng */
>>       &__clk_0_50, /* ssi.1 */
>>       &__clk_0_53, /* enet-fec */
>>       &__clk_0_54, /* enet-fec */
>> diff --git a/arch/m68k/include/asm/m5441xsim.h b/arch/m68k/include/ 
>> asm/m5441xsim.h
>> index f48cf63bd782..dd64cdfcad3e 100644
>> --- a/arch/m68k/include/asm/m5441xsim.h
>> +++ b/arch/m68k/include/asm/m5441xsim.h
>> @@ -198,6 +198,15 @@
>>   #define MCFRTC_SIZE        (0xfc0a8840 - 0xfc0a8000)
>>   #define MCF_IRQ_RTC        (MCFINT2_VECBASE + MCFINT2_RTC)
>> +/*
>> + *  Random Number Generator (RNG) Module.
>> + *  Note: Only present in MCF54418, not in MCF54410/54415/54417
>> + */
>> +#define MCF_RNG_BASE        0xfc0c4000
>> +#define MCF_RNG_SIZE        0x1c
>> +#define MCFINT2_RNG        28
>> +#define MCF_IRQ_RNG        (MCFINT2_VECBASE + MCFINT2_RNG)
>> +
>>   /*
>>    *  GPIO Module.
>>    */
>> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/ 
>> Kconfig
>> index 492a2a61a65b..2f301e43db84 100644
>> --- a/drivers/char/hw_random/Kconfig
>> +++ b/drivers/char/hw_random/Kconfig
>> @@ -270,12 +270,13 @@ config HW_RANDOM_MXC_RNGA
>>   config HW_RANDOM_IMX_RNGC
>>       tristate "Freescale i.MX RNGC Random Number Generator"
>>       depends on HAS_IOMEM
>> -    depends on SOC_IMX25 || SOC_IMX6SL || SOC_IMX6SLL || SOC_IMX6UL 
>> || COMPILE_TEST
>> +    depends on SOC_IMX25 || SOC_IMX6SL || SOC_IMX6SLL || SOC_IMX6UL 
>> || COLDFIRE || COMPILE_TEST
>>       default HW_RANDOM
>>       help
>>         This driver provides kernel-side support for the Random Number
>>         Generator Version C hardware found on some Freescale i.MX
>>         processors. Version B is also supported by this driver.
>> +      Also supports RNGB on Freescale MCF54418 (Coldfire V4e).
>>         To compile this driver as a module, choose M here: the
>>         module will be called imx-rngc.
>> diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/ 
>> hw_random/imx-rngc.c
>> index d6a847e48339..44f20a05de0a 100644
>> --- a/drivers/char/hw_random/imx-rngc.c
>> +++ b/drivers/char/hw_random/imx-rngc.c
>> @@ -353,12 +353,19 @@ static const struct of_device_id 
>> imx_rngc_dt_ids[] = {
>>   };
>>   MODULE_DEVICE_TABLE(of, imx_rngc_dt_ids);
>> +static const struct platform_device_id imx_rngc_devtype[] = {
>> +    { .name = "imx-rngc" },
>> +    { /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(platform, imx_rngc_devtype);
>> +
>>   static struct platform_driver imx_rngc_driver = {
>>       .driver = {
>>           .name = KBUILD_MODNAME,
>>           .pm = pm_ptr(&imx_rngc_pm_ops),
>>           .of_match_table = imx_rngc_dt_ids,
>>       },
>> +    .id_table = imx_rngc_devtype,
>>   };
>>   module_platform_driver_probe(imx_rngc_driver, imx_rngc_probe);
>>
> 

Re: [PATCH v4 2/2] m68k: coldfire: Add RNG support for MCF54418

[Greg Ungerer]

Hi JM,

On 19/8/26 01:09, Jean-Michel Hautbois wrote:
> Hi Greg,
> 
> Sorry for the very long silence on this one, it fell off my radar...
> 
> Le 03/12/2025 à 13:15, Greg Ungerer a écrit :
>> Hi Jean-Michel,
>>
>> On 26/11/25 17:08, Jean-Michel Hautbois via B4 Relay wrote:
>>> From: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
>>>
>>> Add support for the hardware Random Number Generator (RNGB) found on
>>> MCF54418 ColdFire processors with clock enabled at platform
>>> initialization.
>>>
>>> The RNGB block is compatible with the imx-rngc driver.
>>>
>>> Reviewed-by: Frank Li <Frank.Li@nxp.com>
>>> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
>>> ---
>>>   arch/m68k/coldfire/device.c       | 28 ++++++++++++++++++++++++++++
>>>   arch/m68k/coldfire/m5441x.c       |  2 +-
>>>   arch/m68k/include/asm/m5441xsim.h |  9 +++++++++
>>>   drivers/char/hw_random/Kconfig    |  3 ++-
>>>   drivers/char/hw_random/imx-rngc.c |  7 +++++++
>>>   5 files changed, 47 insertions(+), 2 deletions(-)
>>
>> I am happy with the ColdFire arch parts, so from me:
>>
>>      Acked-by: Greg Ungerer <gerg@linux-m68k.org>
>>
>> I don't mind taking this commit via the m68knommu git tree if the hw_rng
>> maintainers are ok with that. Otherwise if you break out the arch/m68k
>> parts I can apply those on their own.
> 
> I think Herbert acked ?
> Do you need another ack ?

I would like to see an acknowledgement that taking this patch via the
m68knommu git tree (to Linus) is ok with the RNG maintainers.

Regards
Greg



> Thanks !
> JM
> 
>> Regards
>> Greg
>>
>>
>>
>>> diff --git a/arch/m68k/coldfire/device.c b/arch/m68k/coldfire/device.c
>>> index b6958ec2a220..9d8f844e319a 100644
>>> --- a/arch/m68k/coldfire/device.c
>>> +++ b/arch/m68k/coldfire/device.c
>>> @@ -622,6 +622,31 @@ static struct platform_device mcf_flexcan0 = {
>>>   };
>>>   #endif /* MCFFLEXCAN_SIZE */
>>> +#ifdef MCF_RNG_BASE
>>> +/*
>>> + * Random Number Generator (RNG) - only on MCF54418
>>> + */
>>> +static struct resource mcf_rng_resource[] = {
>>> +    {
>>> +        .start = MCF_RNG_BASE,
>>> +        .end   = MCF_RNG_BASE + MCF_RNG_SIZE - 1,
>>> +        .flags = IORESOURCE_MEM,
>>> +    },
>>> +    {
>>> +        .start = MCF_IRQ_RNG,
>>> +        .end   = MCF_IRQ_RNG,
>>> +        .flags = IORESOURCE_IRQ,
>>> +    },
>>> +};
>>> +
>>> +static struct platform_device mcf_rng = {
>>> +    .name           = "imx-rngc",
>>> +    .id             = -1,
>>> +    .num_resources  = ARRAY_SIZE(mcf_rng_resource),
>>> +    .resource       = mcf_rng_resource,
>>> +};
>>> +#endif /* MCF_RNG_BASE */
>>> +
>>>   static struct platform_device *mcf_devices[] __initdata = {
>>>       &mcf_uart,
>>>   #ifdef MCFFEC_BASE0
>>> @@ -660,6 +685,9 @@ static struct platform_device *mcf_devices[] 
>>> __initdata = {
>>>   #ifdef MCFFLEXCAN_SIZE
>>>       &mcf_flexcan0,
>>>   #endif
>>> +#ifdef MCF_RNG_BASE
>>> +    &mcf_rng,
>>> +#endif
>>>   };
>>>   /*
>>> diff --git a/arch/m68k/coldfire/m5441x.c b/arch/m68k/coldfire/m5441x.c
>>> index 7a25cfc7ac07..ab5b00637237 100644
>>> --- a/arch/m68k/coldfire/m5441x.c
>>> +++ b/arch/m68k/coldfire/m5441x.c
>>> @@ -158,6 +158,7 @@ static struct clk * const enable_clks[] 
>>> __initconst = {
>>>       &__clk_0_33, /* pit.1 */
>>>       &__clk_0_37, /* eport */
>>>       &__clk_0_48, /* pll */
>>> +    &__clk_0_49, /* rng */
>>>       &__clk_0_51, /* esdhc */
>>>       &__clk_1_36, /* CCM/reset module/Power management */
>>> @@ -179,7 +180,6 @@ static struct clk * const disable_clks[] 
>>> __initconst = {
>>>       &__clk_0_44, /* usb otg */
>>>       &__clk_0_45, /* usb host */
>>>       &__clk_0_47, /* ssi.0 */
>>> -    &__clk_0_49, /* rng */
>>>       &__clk_0_50, /* ssi.1 */
>>>       &__clk_0_53, /* enet-fec */
>>>       &__clk_0_54, /* enet-fec */
>>> diff --git a/arch/m68k/include/asm/m5441xsim.h b/arch/m68k/include/ 
>>> asm/m5441xsim.h
>>> index f48cf63bd782..dd64cdfcad3e 100644
>>> --- a/arch/m68k/include/asm/m5441xsim.h
>>> +++ b/arch/m68k/include/asm/m5441xsim.h
>>> @@ -198,6 +198,15 @@
>>>   #define MCFRTC_SIZE        (0xfc0a8840 - 0xfc0a8000)
>>>   #define MCF_IRQ_RTC        (MCFINT2_VECBASE + MCFINT2_RTC)
>>> +/*
>>> + *  Random Number Generator (RNG) Module.
>>> + *  Note: Only present in MCF54418, not in MCF54410/54415/54417
>>> + */
>>> +#define MCF_RNG_BASE        0xfc0c4000
>>> +#define MCF_RNG_SIZE        0x1c
>>> +#define MCFINT2_RNG        28
>>> +#define MCF_IRQ_RNG        (MCFINT2_VECBASE + MCFINT2_RNG)
>>> +
>>>   /*
>>>    *  GPIO Module.
>>>    */
>>> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/ 
>>> Kconfig
>>> index 492a2a61a65b..2f301e43db84 100644
>>> --- a/drivers/char/hw_random/Kconfig
>>> +++ b/drivers/char/hw_random/Kconfig
>>> @@ -270,12 +270,13 @@ config HW_RANDOM_MXC_RNGA
>>>   config HW_RANDOM_IMX_RNGC
>>>       tristate "Freescale i.MX RNGC Random Number Generator"
>>>       depends on HAS_IOMEM
>>> -    depends on SOC_IMX25 || SOC_IMX6SL || SOC_IMX6SLL || SOC_IMX6UL 
>>> || COMPILE_TEST
>>> +    depends on SOC_IMX25 || SOC_IMX6SL || SOC_IMX6SLL || SOC_IMX6UL 
>>> || COLDFIRE || COMPILE_TEST
>>>       default HW_RANDOM
>>>       help
>>>         This driver provides kernel-side support for the Random Number
>>>         Generator Version C hardware found on some Freescale i.MX
>>>         processors. Version B is also supported by this driver.
>>> +      Also supports RNGB on Freescale MCF54418 (Coldfire V4e).
>>>         To compile this driver as a module, choose M here: the
>>>         module will be called imx-rngc.
>>> diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/ 
>>> hw_random/imx-rngc.c
>>> index d6a847e48339..44f20a05de0a 100644
>>> --- a/drivers/char/hw_random/imx-rngc.c
>>> +++ b/drivers/char/hw_random/imx-rngc.c
>>> @@ -353,12 +353,19 @@ static const struct of_device_id 
>>> imx_rngc_dt_ids[] = {
>>>   };
>>>   MODULE_DEVICE_TABLE(of, imx_rngc_dt_ids);
>>> +static const struct platform_device_id imx_rngc_devtype[] = {
>>> +    { .name = "imx-rngc" },
>>> +    { /* sentinel */ }
>>> +};
>>> +MODULE_DEVICE_TABLE(platform, imx_rngc_devtype);
>>> +
>>>   static struct platform_driver imx_rngc_driver = {
>>>       .driver = {
>>>           .name = KBUILD_MODNAME,
>>>           .pm = pm_ptr(&imx_rngc_pm_ops),
>>>           .of_match_table = imx_rngc_dt_ids,
>>>       },
>>> +    .id_table = imx_rngc_devtype,
>>>   };
>>>   module_platform_driver_probe(imx_rngc_driver, imx_rngc_probe);
>>>
>>
> 

Re: [PATCH v4 2/2] m68k: coldfire: Add RNG support for MCF54418

[Jean-Michel Hautbois]

Herbert, Greg,

Gentle ping, and the delay is mostly mine: this sat on my own list for
months. The series has had all the acks it needs since December 2025,
but Greg would like your word before taking the arch half[1].

The two patches are independent at build time, so the simplest path is
the one Greg suggested himself[2]: 1/2 through crypto, 2/2 through
m68knommu. 2/2 is mostly arch code, but it also adds COLDFIRE to the
HW_RANDOM_IMX_RNGC dependency and a platform id_table to imx-rngc.c[3],
so it needs your ack for Greg to take it.

Both still apply with git am -3 on current mainline and on
m68knommu/for-next. Happy to send a rebased v5 instead, no rush.

[1] https://lore.kernel.org/all/9ba1ebd8-61cc-4e1a-b68d-906b20dd4999@polyxeno.com
[2] https://lore.kernel.org/all/bd25e903-30fc-4905-986c-96d1b42e9f02@linux-m68k.org
[3] https://lore.kernel.org/all/20251126-b4-m5441x-add-rng-support-v4-2-5309548c9555@yoseli.org

Thanks,
JM

Re: [PATCH v4 2/2] m68k: coldfire: Add RNG support for MCF54418

[Herbert Xu]

On Wed, Aug 19, 2026 at 07:36:36AM +1000, Greg Ungerer wrote:
> Hi JM,
> 
> On 19/8/26 01:09, Jean-Michel Hautbois wrote:
> > Hi Greg,
> > 
> > Sorry for the very long silence on this one, it fell off my radar...
> > 
> > Le 03/12/2025 à 13:15, Greg Ungerer a écrit :
> > > Hi Jean-Michel,
> > > 
> > > On 26/11/25 17:08, Jean-Michel Hautbois via B4 Relay wrote:
> > > > From: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> > > > 
> > > > Add support for the hardware Random Number Generator (RNGB) found on
> > > > MCF54418 ColdFire processors with clock enabled at platform
> > > > initialization.
> > > > 
> > > > The RNGB block is compatible with the imx-rngc driver.
> > > > 
> > > > Reviewed-by: Frank Li <Frank.Li@nxp.com>
> > > > Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> > > > ---
> > > >   arch/m68k/coldfire/device.c       | 28 ++++++++++++++++++++++++++++
> > > >   arch/m68k/coldfire/m5441x.c       |  2 +-
> > > >   arch/m68k/include/asm/m5441xsim.h |  9 +++++++++
> > > >   drivers/char/hw_random/Kconfig    |  3 ++-
> > > >   drivers/char/hw_random/imx-rngc.c |  7 +++++++
> > > >   5 files changed, 47 insertions(+), 2 deletions(-)
> > > 
> > > I am happy with the ColdFire arch parts, so from me:
> > > 
> > >      Acked-by: Greg Ungerer <gerg@linux-m68k.org>
> > > 
> > > I don't mind taking this commit via the m68knommu git tree if the hw_rng
> > > maintainers are ok with that. Otherwise if you break out the arch/m68k
> > > parts I can apply those on their own.
> > 
> > I think Herbert acked ?
> > Do you need another ack ?
> 
> I would like to see an acknowledgement that taking this patch via the
> m68knommu git tree (to Linus) is ok with the RNG maintainers.

I have no objections to this.

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt