Also attach as a regulator if the FDT provides the fixed voltage value.

Restore fixed voltage at reboot time to prevent hangs after a warm reset
if DVFS is active.

diff --git a/sys/dev/fdt/sypwr.c b/sys/dev/fdt/sypwr.c
index e626256..5a0b5c8 100644 (file)
--- a/sys/dev/fdt/sypwr.c
+++ b/sys/dev/fdt/sypwr.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: sypwr.c,v 1.1 2017/12/31 11:13:59 kettenis Exp $      */
+/*     $OpenBSD: sypwr.c,v 1.2 2018/08/03 21:07:34 kettenis Exp $      */
 /*
  * Copyright (c) 2017 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -35,14 +35,18 @@ struct sypwr_softc {
        i2c_tag_t       sc_tag;
        i2c_addr_t      sc_addr;
 
+       uint32_t        sc_fixed_microvolt;
+
        struct regulator_device sc_rd;
 };
 
 int    sypwr_match(struct device *, void *, void *);
 void   sypwr_attach(struct device *, struct device *, void *);
+int    sypwr_activate(struct device *, int);
 
 struct cfattach sypwr_ca = {
-       sizeof(struct sypwr_softc), sypwr_match, sypwr_attach
+       sizeof(struct sypwr_softc), sypwr_match, sypwr_attach,
+       NULL, sypwr_activate
 };
 
 struct cfdriver sypwr_cd = {
@@ -74,14 +78,18 @@ sypwr_attach(struct device *parent, struct device *self, void *aux)
        sc->sc_tag = ia->ia_tag;
        sc->sc_addr = ia->ia_addr;
 
+       sc->sc_fixed_microvolt =
+           OF_getpropint(node, "silergy,fixed-microvolt", 0);
+
        /*
         * Only register the regulator if it is under I2C control
-        * (i.e. initialized by the firmware).  Otherwise we have no
-        * idea what the current output voltage is, which will confuse
-        * the regulator framework.
+        * (i.e. initialized by the firmware) or if the device tree
+        * specifies its fixed voltage.  Otherwise we have no idea
+        * what the current output voltage is, which will confuse the
+        * regulator framework.
         */
        reg = sypwr_read(sc, SY8106A_VOUT1_SEL);
-       if (reg & SY8106A_VOUT1_SEL_I2C) {
+       if (reg & SY8106A_VOUT1_SEL_I2C || sc->sc_fixed_microvolt != 0) {
                uint32_t voltage;
 
                voltage = sypwr_get_voltage(sc);
@@ -98,6 +106,29 @@ sypwr_attach(struct device *parent, struct device *self, void *aux)
        printf("\n");
 }
 
+int
+sypwr_activate(struct device *self, int act)
+{
+       struct sypwr_softc *sc = (struct sypwr_softc *)self;
+       uint8_t reg;
+
+       switch (act) {
+       case DVACT_POWERDOWN:
+               /*
+                * Restore fixed voltage otherwise we might hang after
+                * a warm reset.
+                */
+               if (sc->sc_fixed_microvolt != 0) {
+                       reg = sypwr_read(sc, SY8106A_VOUT1_SEL);
+                       reg &= ~SY8106A_VOUT1_SEL_I2C;
+                       sypwr_write(sc, SY8106A_VOUT1_SEL, reg);
+               }
+               break;
+       }
+
+       return 0;
+}
+
 uint8_t
 sypwr_read(struct sypwr_softc *sc, int reg)
 {
@@ -144,7 +175,10 @@ sypwr_get_voltage(void *cookie)
        uint8_t value;
        
        value = sypwr_read(sc, SY8106A_VOUT1_SEL);
-       return 680000 + (value & SY8106A_VOUT1_SEL_MASK) * 10000;
+       if (value & SY8106A_VOUT1_SEL_I2C)
+               return 680000 + (value & SY8106A_VOUT1_SEL_MASK) * 10000;
+       else
+               return sc->sc_fixed_microvolt;
 }
 
 int