From 3b48d9c0d4279ed4966d7521c956f131e18a83e8 Mon Sep 17 00:00:00 2001
From: phessler <phessler@openbsd.org>
Date: Fri, 28 Apr 2023 05:13:37 +0000
Subject: [PATCH] Add a driver for the Qualcomm rng device found on the
 Thinkpad X13s, based on kettenis's amlrng driver.

suggestions and OK patrick@
---
 sys/arch/arm64/conf/GENERIC |  3 +-
 sys/arch/arm64/conf/RAMDISK |  3 +-
 sys/dev/fdt/files.fdt       |  7 ++-
 sys/dev/fdt/qcrng.c         | 98 +++++++++++++++++++++++++++++++++++++
 4 files changed, 108 insertions(+), 3 deletions(-)
 create mode 100644 sys/dev/fdt/qcrng.c

diff --git a/sys/arch/arm64/conf/GENERIC b/sys/arch/arm64/conf/GENERIC
index edb65a3ef41..0b13e8c4e4b 100644
--- a/sys/arch/arm64/conf/GENERIC
+++ b/sys/arch/arm64/conf/GENERIC
@@ -1,4 +1,4 @@
-# $OpenBSD: GENERIC,v 1.266 2023/04/20 19:28:30 jcs Exp $
+# $OpenBSD: GENERIC,v 1.267 2023/04/28 05:13:37 phessler Exp $
 #
 # GENERIC machine description file
 #
@@ -333,6 +333,7 @@ qcpmic*		at qcspmi?
 qcpmicgpio*	at qcpmic?
 qcpon*		at qcpmic?
 qcpwm*		at qcpmic?
+qcrng*		at fdt?
 qcrtc*		at qcpmic?
 
 # Sunxi SoCs
diff --git a/sys/arch/arm64/conf/RAMDISK b/sys/arch/arm64/conf/RAMDISK
index d630c574a68..6d42fda91e5 100644
--- a/sys/arch/arm64/conf/RAMDISK
+++ b/sys/arch/arm64/conf/RAMDISK
@@ -1,4 +1,4 @@
-# $OpenBSD: RAMDISK,v 1.198 2023/04/20 19:28:30 jcs Exp $
+# $OpenBSD: RAMDISK,v 1.199 2023/04/28 05:13:37 phessler Exp $
 
 machine		arm64
 maxusers	4
@@ -257,6 +257,7 @@ qcpmic*		at qcspmi?
 qcpmicgpio*	at qcpmic?
 qcpon*		at qcpmic?
 qcpwm*		at qcpmic?
+qcrng*		at fdt?
 qcrtc*		at qcpmic?
 
 # Sunxi SoCs
diff --git a/sys/dev/fdt/files.fdt b/sys/dev/fdt/files.fdt
index 5df8d8572c8..5182538a391 100644
--- a/sys/dev/fdt/files.fdt
+++ b/sys/dev/fdt/files.fdt
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.fdt,v 1.186 2023/04/19 00:19:17 dlg Exp $
+#	$OpenBSD: files.fdt,v 1.187 2023/04/28 05:13:37 phessler Exp $
 #
 # Config file and device description for machine-independent FDT code.
 # Included by ports that need it.
@@ -711,6 +711,11 @@ device	qcpwm
 attach	qcpwm at spmi
 file	dev/fdt/qcpwm.c			qcpwm
 
+# Qualcomm RNG
+device	qcrng
+attach	qcrng at fdt
+file	dev/fdt/qcrng.c			qcrng
+
 # Qualcomm PMIC RTC
 device	qcrtc
 attach	qcrtc at spmi
diff --git a/sys/dev/fdt/qcrng.c b/sys/dev/fdt/qcrng.c
new file mode 100644
index 00000000000..c95c0a72573
--- /dev/null
+++ b/sys/dev/fdt/qcrng.c
@@ -0,0 +1,98 @@
+/*	$OpenBSD: qcrng.c,v 1.1 2023/04/28 05:13:37 phessler Exp $	*/
+/*
+ * Copyright (c) 2019 Mark Kettenis <kettenis@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/ofw/openfirm.h>
+#include <dev/ofw/fdt.h>
+
+/* Registers */
+#define RNG_DATA		0x0000
+#define RNG_STATUS		0x0004
+
+#define HREAD4(sc, reg)							\
+	(bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
+
+struct qcrng_softc {
+	struct device		sc_dev;
+	bus_space_tag_t		sc_iot;
+	bus_space_handle_t	sc_ioh;
+
+	struct timeout		sc_to;
+};
+
+int	qcrng_match(struct device *, void *, void *);
+void	qcrng_attach(struct device *, struct device *, void *);
+
+const struct cfattach	qcrng_ca = {
+	sizeof (struct qcrng_softc), qcrng_match, qcrng_attach
+};
+
+struct cfdriver qcrng_cd = {
+	NULL, "qcrng", DV_DULL
+};
+
+void	qcrng_rnd(void *);
+
+int
+qcrng_match(struct device *parent, void *match, void *aux)
+{
+	struct fdt_attach_args *faa = aux;
+
+	return OF_is_compatible(faa->fa_node, "qcom,prng-ee");
+}
+
+void
+qcrng_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct qcrng_softc *sc = (struct qcrng_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");
+
+	timeout_set(&sc->sc_to, qcrng_rnd, sc);
+	qcrng_rnd(sc);
+}
+
+void
+qcrng_rnd(void *arg)
+{
+	struct qcrng_softc *sc = arg;
+
+	if (HREAD4(sc, RNG_STATUS) & 0x1)
+		enqueue_randomness(HREAD4(sc, RNG_DATA));
+
+	timeout_add_sec(&sc->sc_to, 1);
+}
-- 
2.20.1