So the random number generator on the Raspberry Pi 4 is a different
design than what was present on earlier models. Here is a driver.
The ACPI tables don't list this device, so only FDT support for now.
ok?
Index: arch/arm64/conf/GENERIC
===================================================================
RCS file: /cvs/src/sys/arch/arm64/conf/GENERIC,v
retrieving revision 1.152
diff -u -p -r1.152 GENERIC
--- arch/arm64/conf/GENERIC 19 Apr 2020 09:20:45 -0000 1.152
+++ arch/arm64/conf/GENERIC 19 Apr 2020 10:42:31 -0000
@@ -142,6 +142,7 @@ imxtmu* at fdt?
bcmaux* at fdt?
bcmintc* at fdt?
bcmdog* at fdt?
+bcmirng* at fdt?
bcmpcie* at fdt?
pci* at bcmpcie?
bcmrng* at fdt?
Index: arch/arm64/conf/RAMDISK
===================================================================
RCS file: /cvs/src/sys/arch/arm64/conf/RAMDISK,v
retrieving revision 1.115
diff -u -p -r1.115 RAMDISK
--- arch/arm64/conf/RAMDISK 19 Apr 2020 09:20:45 -0000 1.115
+++ arch/arm64/conf/RAMDISK 19 Apr 2020 10:42:31 -0000
@@ -128,6 +128,7 @@ sdmmc* at imxesdhc?
bcmaux* at fdt?
bcmintc* at fdt?
bcmdog* at fdt?
+bcmirng* at fdt?
bcmpcie* at fdt?
pci* at bcmpcie?
bcmrng* at fdt?
Index: dev/acpi/files.acpi
===================================================================
RCS file: /cvs/src/sys/dev/acpi/files.acpi,v
retrieving revision 1.54
diff -u -p -r1.54 files.acpi
--- dev/acpi/files.acpi 14 Apr 2020 21:02:39 -0000 1.54
+++ dev/acpi/files.acpi 19 Apr 2020 10:42:31 -0000
@@ -213,6 +213,10 @@ device amdgpio
attach amdgpio at acpi
file dev/acpi/amdgpio.c amdgpio
-# Broadcom BC7XXX Ethernet controller
+# Broadcom BCM2835/2711 random number generator
+attach bcmrng at acpi with bcmrng_acpi
+file dev/acpi/bcmrng_acpi.c bcmrng_acpi
+
+# Broadcom BCM7XXX Ethernet controller
attach bse at acpi with bse_acpi
file dev/acpi/if_bse_acpi.c bse_acpi
Index: dev/fdt/bcm2838_rng.c
===================================================================
RCS file: dev/fdt/bcm2838_rng.c
diff -N dev/fdt/bcm2838_rng.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ dev/fdt/bcm2838_rng.c 19 Apr 2020 10:42:31 -0000
@@ -0,0 +1,112 @@
+/* $OpenBSD: bcm2835_rng.c,v 1.2 2018/04/28 15:44:59 jasper Exp $ */
+/*
+ * Copyright (c) 2020 Mark Kettenis <kette...@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/timeout.h>
+
+#include <machine/bus.h>
+#include <machine/fdt.h>
+
+#include <dev/rndvar.h>
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/fdt.h>
+
+/* Registers */
+#define RNG_CTRL 0x0000
+#define RNG_CTRL_RBGEN_MASK (0x1fff << 0)
+#define RNG_CTRL_RBGEN_EN (1 << 0)
+#define RNG_FIFO_DATA 0x0020
+#define RNG_FIFO_COUNT 0x0024
+#define RNG_FIFO_COUNT_MASK (0xff << 0)
+
+#define HREAD4(sc, reg)
\
+ (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
+#define HWRITE4(sc, reg, val) \
+ bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val))
+
+struct bcmirng_softc {
+ struct device sc_dev;
+ bus_space_tag_t sc_iot;
+ bus_space_handle_t sc_ioh;
+
+ struct timeout sc_to;
+};
+
+int bcmirng_match(struct device *, void *, void *);
+void bcmirng_attach(struct device *, struct device *, void *);
+
+struct cfattach bcmirng_ca = {
+ sizeof (struct bcmirng_softc), bcmirng_match, bcmirng_attach
+};
+
+struct cfdriver bcmirng_cd = {
+ NULL, "bcmirng", DV_DULL
+};
+
+void bcmirng_rnd(void *);
+
+int
+bcmirng_match(struct device *parent, void *match, void *aux)
+{
+ struct fdt_attach_args *faa = aux;
+
+ return OF_is_compatible(faa->fa_node, "brcm,bcm2838-rng200");
+}
+
+void
+bcmirng_attach(struct device *parent, struct device *self, void *aux)
+{
+ struct bcmirng_softc *sc = (struct bcmirng_softc *)self;
+ struct fdt_attach_args *faa = aux;
+
+ if (faa->fa_nreg < 1) {
+ printf(": no registers\n");
+ return;
+ }
+
+ sc->sc_iot = faa->fa_iot;
+ if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
+ faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
+ printf(": can't map registers\n");
+ return;
+ }
+
+ printf("\n");
+
+ HWRITE4(sc, RNG_CTRL, RNG_CTRL_RBGEN_EN);
+
+ timeout_set(&sc->sc_to, bcmirng_rnd, sc);
+ bcmirng_rnd(sc);
+}
+
+void
+bcmirng_rnd(void *arg)
+{
+ struct bcmirng_softc *sc = arg;
+ uint32_t data;
+ int count, i;
+
+ count = MAX(4, HREAD4(sc, RNG_FIFO_COUNT) & RNG_FIFO_COUNT_MASK);
+ for (i = 0; i < count; i++) {
+ data = HREAD4(sc, RNG_FIFO_DATA);
+ enqueue_randomness(data);
+ }
+
+ timeout_add_sec(&sc->sc_to, 1);
+}
Index: dev/fdt/files.fdt
===================================================================
RCS file: /cvs/src/sys/dev/fdt/files.fdt,v
retrieving revision 1.119
diff -u -p -r1.119 files.fdt
--- dev/fdt/files.fdt 19 Apr 2020 09:20:45 -0000 1.119
+++ dev/fdt/files.fdt 19 Apr 2020 10:42:31 -0000
@@ -85,6 +85,10 @@ device bcmdog
attach bcmdog at fdt
file dev/fdt/bcm2835_dog.c bcmdog
+device bcmirng
+attach bcmirng at fdt
+file dev/fdt/bcm2838_rng.c bcmirng
+
device bcmpcie: pcibus
attach bcmpcie at fdt
file dev/fdt/bcm2711_pcie.c bcmpcie
