Adjust support for "syscon-reboot" and "syscon-poweroff" for the updated

bindings in mainline Linux.  Necessary to support the QEMY RISCV target.

ok jsg@

diff --git a/sys/dev/fdt/syscon.c b/sys/dev/fdt/syscon.c
index fe6de25..0116d59 100644 (file)
--- a/sys/dev/fdt/syscon.c
+++ b/sys/dev/fdt/syscon.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: syscon.c,v 1.4 2018/03/17 18:04:15 kettenis Exp $     */
+/*     $OpenBSD: syscon.c,v 1.5 2021/04/23 12:38:00 kettenis Exp $     */
 /*
  * Copyright (c) 2017 Mark Kettenis
  *
@@ -42,6 +42,7 @@ struct syscon_softc {
        uint32_t                sc_regmap;
        bus_size_t              sc_offset;
        uint32_t                sc_mask;
+       uint32_t                sc_value;
 };
 
 struct syscon_softc *syscon_reboot_sc;
@@ -110,12 +111,26 @@ syscon_attach(struct device *parent, struct device *self, void *aux)
                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))
+               if (OF_getproplen(faa->fa_node, "offset") != sizeof(uint32_t))
+                       return;
+
+               /* At least one of "mask" and "value" should be provided. */
+               if (OF_getproplen(faa->fa_node, "mask") != sizeof(uint32_t) &&
+                   OF_getproplen(faa->fa_node, "value") != sizeof(uint32_t))
                        return;
 
                sc->sc_offset = OF_getpropint(faa->fa_node, "offset", 0);
-               sc->sc_mask = OF_getpropint(faa->fa_node, "mask", 0);
+               sc->sc_mask = OF_getpropint(faa->fa_node, "mask", 0xffffffff);
+               sc->sc_value = OF_getpropint(faa->fa_node, "value", 0);
+
+               /*
+                * Old binding used "mask" as the value to write with
+                * an all-ones mask.  This is still supported.
+                */
+               if (OF_getproplen(faa->fa_node, "value") != sizeof(uint32_t)) {
+                       sc->sc_value = sc->sc_mask;
+                       sc->sc_mask = 0xffffffff;
+               }
 
                if (OF_is_compatible(faa->fa_node, "syscon-reboot")) {
                        syscon_reboot_sc = sc;
@@ -132,12 +147,16 @@ syscon_reset(void)
 {
        struct syscon_softc *sc = syscon_reboot_sc;
        struct regmap *rm;
+       uint32_t value;
 
        rm = regmap_byphandle(sc->sc_regmap);
        if (rm == NULL)
                return;
 
-       regmap_write_4(rm, sc->sc_offset, sc->sc_mask);
+       value = regmap_read_4(rm, sc->sc_offset);
+       value &= ~sc->sc_mask;
+       value |= sc->sc_value;
+       regmap_write_4(rm, sc->sc_offset, value);
        delay(1000000);
 }
 
@@ -146,11 +165,15 @@ syscon_powerdown(void)
 {
        struct syscon_softc *sc = syscon_poweroff_sc;
        struct regmap *rm;
+       uint32_t value;
 
        rm = regmap_byphandle(sc->sc_regmap);
        if (rm == NULL)
                return;
 
-       regmap_write_4(rm, sc->sc_offset, sc->sc_mask);
+       value = regmap_read_4(rm, sc->sc_offset);
+       value &= ~sc->sc_mask;
+       value |= sc->sc_value;
+       regmap_write_4(rm, sc->sc_offset, value);
        delay(1000000);
 }