Most devices integrated on SoCs have a well-defined block of
registers. But sometimes a driver for such a device needs to touch a
register outside that block. In those cases the device tree contains
a reference to the device that "owns" the registers. The diff below
implements a way to access those registers. The device that owns the
registers needs to register a "regmap". Other device can then lookup
that regmap through a phandle and read or write to registers. The
size of the region is store when the regmap is registered, and checked
upon access. Only 32-bit access is implemented for now.
The diff also add a syscon(4) driver that uses the regmap
functionality to implement reboot and poweroff functionality.
ok?
Index: dev/ofw/ofw_misc.c
===================================================================
RCS file: dev/ofw/ofw_misc.c
diff -N dev/ofw/ofw_misc.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ dev/ofw/ofw_misc.c 8 Mar 2017 21:58:30 -0000
@@ -0,0 +1,81 @@
+/* $OpenBSD$ */
+/*
+ * Copyright (c) 2017 Mark Kettenis
+ *
+ * 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/types.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+
+#include <machine/bus.h>
+
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_pinctrl.h>
+
+struct regmap {
+ uint32_t rm_phandle;
+ bus_space_tag_t rm_tag;
+ bus_space_handle_t rm_handle;
+ bus_size_t rm_size;
+
+ LIST_ENTRY(regmap) rm_list;
+};
+
+LIST_HEAD(, regmap) regmaps = LIST_HEAD_INITIALIZER(regmap);
+
+void
+regmap_register(int node, bus_space_tag_t tag, bus_space_handle_t handle,
+ bus_size_t size)
+{
+ struct regmap *rm;
+ uint32_t phandle;
+
+ phandle = OF_getpropint(node, "phandle", 0);
+ if (phandle) {
+ rm = malloc(sizeof(struct regmap), M_DEVBUF, M_WAITOK);
+ rm->rm_phandle = phandle;
+ rm->rm_tag = tag;
+ rm->rm_handle = handle;
+ rm->rm_size = size;
+ LIST_INSERT_HEAD(®maps, rm, rm_list);
+ }
+}
+
+struct regmap *
+regmap_byphandle(uint32_t phandle)
+{
+ struct regmap *rm;
+
+ LIST_FOREACH(rm, ®maps, rm_list) {
+ if (rm->rm_phandle == phandle)
+ return rm;
+ }
+
+ return NULL;
+}
+
+void
+regmap_write_4(struct regmap *rm, bus_size_t offset, uint32_t value)
+{
+ KASSERT(offset <= rm->rm_size - sizeof(uint32_t));
+ bus_space_write_4(rm->rm_tag, rm->rm_handle, offset, value);
+}
+
+uint32_t
+regmap_read_4(struct regmap *rm, bus_size_t offset)
+{
+ KASSERT(offset <= rm->rm_size - sizeof(uint32_t));
+ return bus_space_read_4(rm->rm_tag, rm->rm_handle, offset);
+}
Index: dev/ofw/ofw_misc.h
===================================================================
RCS file: dev/ofw/ofw_misc.h
diff -N dev/ofw/ofw_misc.h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ dev/ofw/ofw_misc.h 8 Mar 2017 21:58:30 -0000
@@ -0,0 +1,29 @@
+/* $OpenBSD$ */
+/*
+ * Copyright (c) 2017 Mark Kettenis
+ *
+ * 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.
+ */
+
+#ifndef _DEV_OFW_MISC_H_
+#define _DEV_OFW_MISC_H_
+
+void regmap_register(int, bus_space_tag_t, bus_space_handle_t, bus_size_t);
+
+struct regmap;
+struct regmap *regmap_byphandle(uint32_t);
+
+uint32_t regmap_read_4(struct regmap *, bus_size_t);
+void regmap_write_4(struct regmap *, bus_size_t, uint32_t);
+
+#endif /* _DEV_OFW_MISC_H_ */
Index: dev/fdt/files.fdt
===================================================================
RCS file: /cvs/src/sys/dev/fdt/files.fdt,v
retrieving revision 1.6
diff -u -p -r1.6 files.fdt
--- dev/fdt/files.fdt 22 Feb 2017 23:01:15 -0000 1.6
+++ dev/fdt/files.fdt 8 Mar 2017 21:58:30 -0000
@@ -46,3 +46,7 @@ file dev/fdt/virtio_mmio.c virtio_mmio
# Advanced Host Controller Interface for Serial ATA
attach ahci at fdt with ahci_fdt
file dev/fdt/ahci_fdt.c ahci_fdt
+
+device syscon
+attach syscon at fdt
+file dev/fdt/syscon.c syscon
Index: dev/fdt/syscon.c
===================================================================
RCS file: dev/fdt/syscon.c
diff -N dev/fdt/syscon.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ dev/fdt/syscon.c 8 Mar 2017 21:58:30 -0000
@@ -0,0 +1,119 @@
+/* $OpenBSD$ */
+/*
+ * Copyright (c) 2016 Mark Kettenis
+ *
+ * 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 <machine/bus.h>
+#include <machine/fdt.h>
+
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_misc.h>
+#include <dev/ofw/fdt.h>
+
+extern void (*cpuresetfn)(void);
+extern void (*powerdownfn)(void);
+
+struct syscon_softc {
+ struct device sc_dev;
+ uint32_t sc_regmap;
+ bus_size_t sc_offset;
+ uint32_t sc_mask;
+};
+
+struct syscon_softc *syscon_reboot_sc;
+struct syscon_softc *syscon_poweroff_sc;
+
+int syscon_match(struct device *, void *, void *);
+void syscon_attach(struct device *, struct device *, void *);
+
+struct cfattach syscon_ca = {
+ sizeof(struct syscon_softc), syscon_match, syscon_attach
+};
+
+struct cfdriver syscon_cd = {
+ NULL, "syscon", DV_DULL
+};
+
+void syscon_reset(void);
+void syscon_powerdown(void);
+
+int
+syscon_match(struct device *parent, void *match, void *aux)
+{
+ struct fdt_attach_args *faa = aux;
+
+ return (OF_is_compatible(faa->fa_node, "syscon-reboot") ||
+ OF_is_compatible(faa->fa_node, "syscon-poweroff"));
+}
+
+void
+syscon_attach(struct device *parent, struct device *self, void *aux)
+{
+ struct syscon_softc *sc = (struct syscon_softc *)self;
+ struct fdt_attach_args *faa = aux;
+
+ printf("\n");
+
+ sc->sc_regmap = OF_getpropint(faa->fa_node, "regmap", 0);
+ if (sc->sc_regmap == 0)
+ return;
+
+ if (OF_getproplen(faa->fa_node, "offset") != sizeof(uint32_t) ||
+ OF_getproplen(faa->fa_node, "mask") != sizeof(uint32_t))
+ return;
+
+ sc->sc_offset = OF_getpropint(faa->fa_node, "offset", 0);
+ sc->sc_mask = OF_getpropint(faa->fa_node, "mask", 0);
+
+ if (OF_is_compatible(faa->fa_node, "syscon-reboot")) {
+ syscon_reboot_sc = sc;
+ cpuresetfn = syscon_reset;
+ } else {
+ syscon_poweroff_sc = sc;
+ powerdownfn = syscon_powerdown;
+ }
+}
+
+void
+syscon_reset(void)
+{
+ struct syscon_softc *sc = syscon_reboot_sc;
+ struct regmap *rm;
+
+ rm = regmap_byphandle(sc->sc_regmap);
+ if (rm == NULL)
+ return;
+
+ regmap_write_4(rm, sc->sc_offset, sc->sc_mask);
+ delay(1000000);
+}
+
+void
+syscon_powerdown(void)
+{
+ struct syscon_softc *sc = syscon_poweroff_sc;
+ struct regmap *rm;
+
+ rm = regmap_byphandle(sc->sc_regmap);
+ if (rm == NULL)
+ return;
+
+ regmap_write_4(rm, sc->sc_offset, sc->sc_mask);
+ delay(1000000);
+}
Index: arch/armv7/conf/GENERIC
===================================================================
RCS file: /cvs/src/sys/arch/armv7/conf/GENERIC,v
retrieving revision 1.76
diff -u -p -r1.76 GENERIC
--- arch/armv7/conf/GENERIC 6 Mar 2017 07:41:58 -0000 1.76
+++ arch/armv7/conf/GENERIC 8 Mar 2017 21:58:30 -0000
@@ -107,6 +107,7 @@ plrtc* at fdt?
virtio* at fdt?
psci* at fdt?
+syscon* at fdt?
simplefb* at fdt?
wsdisplay* at simplefb?
Index: arch/armv7/conf/files.armv7
===================================================================
RCS file: /cvs/src/sys/arch/armv7/conf/files.armv7,v
retrieving revision 1.31
diff -u -p -r1.31 files.armv7
--- arch/armv7/conf/files.armv7 25 Jan 2017 10:14:40 -0000 1.31
+++ arch/armv7/conf/files.armv7 8 Mar 2017 21:58:30 -0000
@@ -27,6 +27,7 @@ file arch/arm/arm/disksubr.c disk
# FDT support
file dev/ofw/ofw_clock.c
file dev/ofw/ofw_gpio.c
+file dev/ofw/ofw_misc.c
file dev/ofw/ofw_pinctrl.c
file dev/ofw/ofw_regulator.c
Index: arch/armv7/exynos/exdog.c
===================================================================
RCS file: /cvs/src/sys/arch/armv7/exynos/exdog.c,v
retrieving revision 1.5
diff -u -p -r1.5 exdog.c
--- arch/armv7/exynos/exdog.c 4 Mar 2017 18:17:24 -0000 1.5
+++ arch/armv7/exynos/exdog.c 8 Mar 2017 21:58:30 -0000
@@ -94,7 +94,8 @@ exdog_attach(struct device *parent, stru
printf("\n");
exdog_sc = sc;
- cpuresetfn = exdog_reset;
+ if (cpuresetfn == NULL)
+ cpuresetfn = exdog_reset;
}
void
Index: arch/armv7/exynos/expower.c
===================================================================
RCS file: /cvs/src/sys/arch/armv7/exynos/expower.c,v
retrieving revision 1.5
diff -u -p -r1.5 expower.c
--- arch/armv7/exynos/expower.c 4 Mar 2017 18:17:24 -0000 1.5
+++ arch/armv7/exynos/expower.c 8 Mar 2017 21:58:30 -0000
@@ -24,6 +24,7 @@
#include <machine/fdt.h>
#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_misc.h>
#include <dev/ofw/fdt.h>
#include <armv7/exynos/expowervar.h>
@@ -85,6 +86,8 @@ expower_attach(struct device *parent, st
printf("\n");
+ regmap_register(faa->fa_node, sc->sc_iot, sc->sc_ioh,
+ faa->fa_reg[0].size);
expower_sc = sc;
}
