Driver name is dsxrtc(4).
ok?
Index: dev/i2c/files.i2c
===================================================================
RCS file: /cvs/src/sys/dev/i2c/files.i2c,v
retrieving revision 1.64
diff -u -p -r1.64 files.i2c
--- dev/i2c/files.i2c 6 Sep 2019 09:38:19 -0000 1.64
+++ dev/i2c/files.i2c 24 Apr 2020 22:43:03 -0000
@@ -84,6 +84,11 @@ device maxds
attach maxds at i2c
file dev/i2c/ds1631.c maxds
+# Maxim DS3231
+device dsxrtc
+attach dsxrtc at i2c
+file dev/i2c/ds3231.c dsxrtc
+
# Apple FCU
device fcu
attach fcu at i2c
Index: dev/i2c/ds3231.c
===================================================================
RCS file: dev/i2c/ds3231.c
diff -N dev/i2c/ds3231.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ dev/i2c/ds3231.c 24 Apr 2020 22:43:03 -0000
@@ -0,0 +1,248 @@
+/* $OpenBSD$ */
+/*
+ * Copyright (c) 2020 Mark Kettenis <kette...@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 <dev/i2c/i2cvar.h>
+
+#include <dev/clock_subr.h>
+
+extern todr_chip_handle_t todr_handle;
+
+#define DS3231_SC 0x00
+#define DS3231_MN 0x01
+#define DS3231_HR 0x02
+#define DS3231_HR_PM (1 << 5)
+#define DS3231_HR_12 (1 << 6)
+#define DS3231_HR_12_MASK ~(DS3231_HR_12 | DS3231_HR_PM)
+#define DS3231_DW 0x03
+#define DS3231_DT 0x04
+#define DS3231_MO 0x05
+#define DS3231_MO_MASK 0x3f
+#define DS3231_YR 0x06
+#define DS3231_SR 0x07
+#define DS3231_SR_OSF (1 << 7)
+
+#define DS3231_NRTC_REGS 7
+
+struct dsxrtc_softc {
+ struct device sc_dev;
+ i2c_tag_t sc_tag;
+ i2c_addr_t sc_addr;
+
+ struct todr_chip_handle sc_todr;
+};
+
+int dsxrtc_match(struct device *, void *, void *);
+void dsxrtc_attach(struct device *, struct device *, void *);
+
+struct cfattach dsxrtc_ca = {
+ sizeof(struct dsxrtc_softc), dsxrtc_match, dsxrtc_attach
+};
+
+struct cfdriver dsxrtc_cd = {
+ NULL, "dsxrtc", DV_DULL
+};
+
+uint8_t dsxrtc_reg_read(struct dsxrtc_softc *, int);
+void dsxrtc_reg_write(struct dsxrtc_softc *, int, uint8_t);
+int dsxrtc_clock_read(struct dsxrtc_softc *, struct clock_ymdhms *);
+int dsxrtc_clock_write(struct dsxrtc_softc *, struct clock_ymdhms *);
+int dsxrtc_gettime(struct todr_chip_handle *, struct timeval *);
+int dsxrtc_settime(struct todr_chip_handle *, struct timeval *);
+
+int
+dsxrtc_match(struct device *parent, void *match, void *aux)
+{
+ struct i2c_attach_args *ia = aux;
+
+ if (strcmp(ia->ia_name, "maxim,ds3231") == 0 ||
+ strcmp(ia->ia_name, "maxim,ds3232") == 0)
+ return 1;
+
+ return 0;
+}
+
+void
+dsxrtc_attach(struct device *parent, struct device *self, void *aux)
+{
+ struct dsxrtc_softc *sc = (struct dsxrtc_softc *)self;
+ struct i2c_attach_args *ia = aux;
+
+ sc->sc_tag = ia->ia_tag;
+ sc->sc_addr = ia->ia_addr;
+
+ sc->sc_todr.cookie = sc;
+ sc->sc_todr.todr_gettime = dsxrtc_gettime;
+ sc->sc_todr.todr_settime = dsxrtc_settime;
+ todr_handle = &sc->sc_todr;
+
+ printf("\n");
+}
+
+int
+dsxrtc_gettime(struct todr_chip_handle *handle, struct timeval *tv)
+{
+ struct dsxrtc_softc *sc = handle->cookie;
+ struct clock_ymdhms dt;
+ int error;
+
+ error = dsxrtc_clock_read(sc, &dt);
+ if (error)
+ return error;
+
+ if (dt.dt_sec > 59 || dt.dt_min > 59 || dt.dt_hour > 23 ||
+ dt.dt_day > 31 || dt.dt_day == 0 ||
+ dt.dt_mon > 12 || dt.dt_mon == 0 ||
+ dt.dt_year < POSIX_BASE_YEAR)
+ return EINVAL;
+
+ tv->tv_sec = clock_ymdhms_to_secs(&dt);
+ tv->tv_usec = 0;
+ return 0;
+}
+
+int
+dsxrtc_settime(struct todr_chip_handle *handle, struct timeval *tv)
+{
+ struct dsxrtc_softc *sc = handle->cookie;
+ struct clock_ymdhms dt;
+
+ clock_secs_to_ymdhms(tv->tv_sec, &dt);
+
+ return dsxrtc_clock_write(sc, &dt);
+
+}
+
+uint8_t
+dsxrtc_reg_read(struct dsxrtc_softc *sc, int reg)
+{
+ uint8_t cmd = reg;
+ uint8_t val;
+ int error;
+
+ iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
+ error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
+ &cmd, sizeof cmd, &val, sizeof val, I2C_F_POLL);
+ iic_release_bus(sc->sc_tag, I2C_F_POLL);
+
+ if (error) {
+ printf("%s: can't read register 0x%02x\n",
+ sc->sc_dev.dv_xname, reg);
+ val = 0xff;
+ }
+
+ return val;
+}
+
+void
+dsxrtc_reg_write(struct dsxrtc_softc *sc, int reg, uint8_t val)
+{
+ uint8_t cmd = reg;
+ int error;
+
+ iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
+ error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr,
+ &cmd, sizeof cmd, &val, sizeof val, I2C_F_POLL);
+ iic_release_bus(sc->sc_tag, I2C_F_POLL);
+
+ if (error) {
+ printf("%s: can't write register 0x%02x\n",
+ sc->sc_dev.dv_xname, reg);
+ }
+}
+
+int
+dsxrtc_clock_read(struct dsxrtc_softc *sc, struct clock_ymdhms *dt)
+{
+ uint8_t regs[DS3231_NRTC_REGS];
+ uint8_t cmd = DS3231_SC;
+ uint8_t status;
+ int error;
+
+ /* Consider the time to be invalid if the OSF bit is set. */
+ status = dsxrtc_reg_read(sc, DS3231_SR);
+ if (status & DS3231_SR_OSF)
+ return EINVAL;
+
+ iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
+ error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
+ &cmd, sizeof(cmd), regs, DS3231_NRTC_REGS, I2C_F_POLL);
+ iic_release_bus(sc->sc_tag, I2C_F_POLL);
+
+ if (error) {
+ printf("%s: can't read RTC\n", sc->sc_dev.dv_xname);
+ return error;
+ }
+
+ /*
+ * Convert the DS3231's register values into something useable.
+ */
+ dt->dt_sec = FROMBCD(regs[0]);
+ dt->dt_min = FROMBCD(regs[1]);
+ if (regs[2] & DS3231_HR_12) {
+ dt->dt_hour = FROMBCD(regs[2] & DS3231_HR_12_MASK);
+ if (regs[2] & DS3231_HR_PM)
+ dt->dt_hour += 12;
+ } else {
+ dt->dt_hour = FROMBCD(regs[2]);
+ }
+ dt->dt_day = FROMBCD(regs[4]);
+ dt->dt_mon = FROMBCD(regs[5] & DS3231_MO_MASK);
+ dt->dt_year = FROMBCD(regs[6]) + 2000;
+
+ return 0;
+}
+
+int
+dsxrtc_clock_write(struct dsxrtc_softc *sc, struct clock_ymdhms *dt)
+{
+ uint8_t regs[DS3231_NRTC_REGS];
+ uint8_t cmd = DS3231_SC;
+ uint8_t status;
+ int error;
+
+ /*
+ * Convert our time representation into something the DS3231
+ * can understand.
+ */
+ regs[0] = TOBCD(dt->dt_sec);
+ regs[1] = TOBCD(dt->dt_min);
+ regs[2] = TOBCD(dt->dt_hour);
+ regs[3] = TOBCD(dt->dt_wday + 1);
+ regs[4] = TOBCD(dt->dt_day);
+ regs[5] = TOBCD(dt->dt_mon);
+ regs[6] = TOBCD(dt->dt_year - 2000);
+
+ iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
+ error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr,
+ &cmd, sizeof(cmd), regs, DS3231_NRTC_REGS, I2C_F_POLL);
+ iic_release_bus(sc->sc_tag, I2C_F_POLL);
+
+ if (error) {
+ printf("%s: can't write RTC\n", sc->sc_dev.dv_xname);
+ return error;
+ }
+
+ /* Clear OSF flag. */
+ status = dsxrtc_reg_read(sc, DS3231_SR);
+ dsxrtc_reg_write(sc, DS3231_SR, status & ~DS3231_SR_OSF);
+
+ return 0;
+}
