Re: [PATCH v4 2/2] m68k: coldfire: Add RNG support for MCF54418
From: Greg Ungerer
Date: Tue Aug 18 2026 - 17:37:45 EST
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@xxxxxxxxxx>
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@xxxxxxx>
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@xxxxxxxxxx>
---
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@xxxxxxxxxxxxxx>
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);