[src/trunk]: src/sys/dev/fdt Add a Google Goldfish RTC driver

[skrll <skrll%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/aad65a6ce35c
branches:  trunk
changeset: 374614:aad65a6ce35c
user:      skrll <skrll%NetBSD.org@localhost>
date:      Mon May 08 07:51:44 2023 +0000

description:
Add a Google Goldfish RTC driver

diffstat:

 sys/dev/fdt/gfrtc_fdt.c |  141 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 141 insertions(+), 0 deletions(-)

diffs (145 lines):

diff -r 3572dfcbd0b3 -r aad65a6ce35c sys/dev/fdt/gfrtc_fdt.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/dev/fdt/gfrtc_fdt.c   Mon May 08 07:51:44 2023 +0000
@@ -0,0 +1,141 @@
+/*     $NetBSD: gfrtc_fdt.c,v 1.1 2023/05/08 07:51:44 skrll Exp $      */
+
+/*-
+ * Copyright (c) 2023 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Nick Hudson
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__KERNEL_RCSID(0, "$NetBSD: gfrtc_fdt.c,v 1.1 2023/05/08 07:51:44 skrll Exp $");
+
+#include <sys/param.h>
+
+#include <sys/bus.h>
+#include <sys/device.h>
+
+#include <dev/fdt/fdtvar.h>
+
+/*
+ * https://android.googlesource.com/platform/external/qemu/+/master/docs/GOLDFISH-VIRTUAL-HARDWARE.TXT
+ */
+
+static const struct device_compatible_entry compat_data[] = {
+       { .compat = "google,goldfish-rtc" },
+       DEVICE_COMPAT_EOL
+};
+
+struct gfrtc_fdt_softc {
+       device_t sc_dev;
+       bus_space_tag_t sc_bst;
+       bus_space_handle_t sc_bsh;
+
+       struct todr_chip_handle sc_todr;
+};
+
+#define        GOLDFISH_RTC_READ(sc, reg) \
+       bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
+#define        GOLDFISH_RTC_WRITE(sc, reg, val) \
+       bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
+
+
+#define        GOLDFISH_RTC_TIME_LOW   0x00
+#define        GOLDFISH_RTC_TIME_HIGH  0x04
+
+
+static int
+gfrtc_gettime(struct todr_chip_handle *ch, struct timeval *tv)
+{
+       struct gfrtc_fdt_softc *sc = ch->cookie;
+       const uint64_t lo = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_LOW);
+       const uint64_t hi = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_HIGH);
+
+       uint64_t nsec = (hi << 32) | lo;
+
+       tv->tv_sec = nsec / 1000000000;
+       tv->tv_usec = (nsec - tv->tv_sec) / 1000;       // Always 0?
+
+       return 0;
+}
+
+static int
+gfrtc_settime(struct todr_chip_handle *ch, struct timeval *tv)
+{
+       struct gfrtc_fdt_softc *sc = ch->cookie;
+
+       uint64_t nsec = (tv->tv_sec * 1000000 + tv->tv_usec) * 1000;
+       uint32_t hi = nsec >> 32;
+       uint32_t lo = nsec;
+
+       GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_TIME_HIGH, hi);
+       GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_TIME_HIGH, lo);
+
+       return 0;
+}
+
+
+static int
+gfrtc_fdt_match(device_t parent, cfdata_t cf, void *aux)
+{
+       struct fdt_attach_args * const faa = aux;
+
+       return of_compatible_match(faa->faa_phandle, compat_data);
+}
+
+static void
+gfrtc_fdt_attach(device_t parent, device_t self, void *aux)
+{
+       struct gfrtc_fdt_softc * const sc = device_private(self);
+       struct fdt_attach_args * const faa = aux;
+       const int phandle = faa->faa_phandle;
+       bus_addr_t addr;
+       bus_size_t size;
+
+       if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
+               aprint_error(": couldn't get registers\n");
+               return;
+       }
+
+       sc->sc_dev = self;
+       sc->sc_bst = faa->faa_bst;
+       if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
+               aprint_error(": couldn't map registers\n");
+               return;
+       }
+
+       aprint_naive("\n");
+       aprint_normal(": Google Goldfish RTC\n");
+
+       sc->sc_todr.cookie = sc;
+       sc->sc_todr.todr_gettime = gfrtc_gettime;
+       sc->sc_todr.todr_settime = gfrtc_settime;
+       sc->sc_todr.todr_setwen = NULL;
+
+       todr_attach(&sc->sc_todr);
+}
+
+CFATTACH_DECL_NEW(gfrtc_fdt, sizeof(struct gfrtc_fdt_softc),
+       gfrtc_fdt_match, gfrtc_fdt_attach, NULL, NULL);