NetBSD/sys/dev/i2c/m41st84.c

536 lines
14 KiB
C

/* $NetBSD: m41st84.c,v 1.32 2021/05/21 21:21:01 macallan Exp $ */
/*
* Copyright (c) 2003 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Steve C. Woodford and Jason R. Thorpe for Wasabi Systems, Inc.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
* 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: m41st84.c,v 1.32 2021/05/21 21:21:01 macallan Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/uio.h>
#include <sys/conf.h>
#include <sys/event.h>
#include <dev/clock_subr.h>
#include <dev/i2c/i2cvar.h>
#include <dev/i2c/m41st84reg.h>
#include <dev/i2c/m41st84var.h>
#include "ioconf.h"
struct strtc_model {
uint16_t sm_model;
uint8_t sm_nvram_start;
uint8_t sm_nvram_size;
uint32_t sm_flags;
};
#define STRTC_F_HAS_WDOG __BIT(0)
static const struct strtc_model m41t80_model = {
.sm_model = 80,
};
static const struct strtc_model m41t81_model = {
.sm_model = 81,
.sm_flags = STRTC_F_HAS_WDOG,
};
static const struct strtc_model m48t84_model = {
.sm_model = 84,
.sm_nvram_start = M41ST84_USER_RAM,
.sm_nvram_size = M41ST84_USER_RAM_SIZE,
.sm_flags = STRTC_F_HAS_WDOG,
};
static const struct device_compatible_entry compat_data[] = {
{ .compat = "st,m41t80", .data = &m41t80_model },
{ .compat = "st,m41t81", .data = &m41t81_model },
{ .compat = "st,m41t84", .data = &m48t84_model },
DEVICE_COMPAT_EOL
};
struct strtc_softc {
device_t sc_dev;
i2c_tag_t sc_tag;
int sc_address;
int sc_open;
const struct strtc_model *sc_model;
struct todr_chip_handle sc_todr;
};
static void strtc_attach(device_t, device_t, void *);
static int strtc_match(device_t, cfdata_t, void *);
CFATTACH_DECL_NEW(strtc, sizeof(struct strtc_softc),
strtc_match, strtc_attach, NULL, NULL);
dev_type_open(strtc_open);
dev_type_close(strtc_close);
dev_type_read(strtc_read);
dev_type_write(strtc_write);
const struct cdevsw strtc_cdevsw = {
.d_open = strtc_open,
.d_close = strtc_close,
.d_read = strtc_read,
.d_write = strtc_write,
.d_ioctl = noioctl,
.d_stop = nostop,
.d_tty = notty,
.d_poll = nopoll,
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
.d_flag = D_OTHER
};
static int strtc_clock_read(struct strtc_softc *sc, struct clock_ymdhms *);
static int strtc_gettime_ymdhms(struct todr_chip_handle *,
struct clock_ymdhms *);
static int strtc_settime_ymdhms(struct todr_chip_handle *,
struct clock_ymdhms *);
static const struct strtc_model *
strtc_model_by_number(u_int model)
{
const struct device_compatible_entry *dce;
const struct strtc_model *sm;
/* no model given; assume it's a 41T80 */
if (model == 0)
return &m41t80_model;
for (dce = compat_data; dce->compat != NULL; dce++) {
sm = dce->data;
if (sm->sm_model == model)
return sm;
}
return NULL;
}
static const struct strtc_model *
strtc_model_by_compat(const struct i2c_attach_args *ia)
{
const struct device_compatible_entry *dce;
const struct strtc_model *sm = NULL;
if ((dce = iic_compatible_lookup(ia, compat_data)) != NULL)
sm = dce->data;
return sm;
}
static int
strtc_match(device_t parent, cfdata_t cf, void *arg)
{
struct i2c_attach_args *ia = arg;
int match_result;
if (iic_use_direct_match(ia, cf, compat_data, &match_result))
return match_result;
if (strtc_model_by_number(cf->cf_flags & 0xffff) == NULL)
return 0;
/* indirect config - check typical address */
if (ia->ia_addr == M41ST84_ADDR)
return I2C_MATCH_ADDRESS_ONLY;
return 0;
}
static void
strtc_attach(device_t parent, device_t self, void *arg)
{
struct strtc_softc *sc = device_private(self);
struct i2c_attach_args *ia = arg;
const struct strtc_model *sm;
if ((sm = strtc_model_by_compat(ia)) == NULL)
sm = strtc_model_by_number(device_cfdata(self)->cf_flags);
if (sm == NULL) {
aprint_error(": unable to determine model!\n");
return;
}
aprint_naive(": Real-time Clock%s\n",
sm->sm_nvram_size ? "/NVRAM" : "");
aprint_normal(": M41T%d Real-time Clock%s\n", sm->sm_model,
sm->sm_nvram_size ? "/NVRAM" : "");
sc->sc_tag = ia->ia_tag;
sc->sc_address = ia->ia_addr;
sc->sc_model = sm;
sc->sc_dev = self;
sc->sc_open = 0;
sc->sc_todr.cookie = sc;
sc->sc_todr.todr_gettime = NULL;
sc->sc_todr.todr_settime = NULL;
sc->sc_todr.todr_gettime_ymdhms = strtc_gettime_ymdhms;
sc->sc_todr.todr_settime_ymdhms = strtc_settime_ymdhms;
sc->sc_todr.todr_setwen = NULL;
todr_attach(&sc->sc_todr);
}
/*ARGSUSED*/
int
strtc_open(dev_t dev, int flag, int fmt, struct lwp *l)
{
struct strtc_softc *sc;
if ((sc = device_lookup_private(&strtc_cd, minor(dev))) == NULL)
return (ENXIO);
/* XXX: Locking */
if (sc->sc_open)
return (EBUSY);
sc->sc_open = 1;
return (0);
}
/*ARGSUSED*/
int
strtc_close(dev_t dev, int flag, int fmt, struct lwp *l)
{
struct strtc_softc *sc;
if ((sc = device_lookup_private(&strtc_cd, minor(dev))) == NULL)
return (ENXIO);
sc->sc_open = 0;
return (0);
}
/*ARGSUSED*/
int
strtc_read(dev_t dev, struct uio *uio, int flags)
{
struct strtc_softc *sc;
u_int8_t ch, cmdbuf[1];
int a, error;
if ((sc = device_lookup_private(&strtc_cd, minor(dev))) == NULL)
return (ENXIO);
const struct strtc_model * const sm = sc->sc_model;
if (uio->uio_offset >= sm->sm_nvram_size)
return (EINVAL);
if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
return (error);
while (uio->uio_resid && uio->uio_offset < sm->sm_nvram_size) {
a = (int)uio->uio_offset;
cmdbuf[0] = a + sm->sm_nvram_start;
if ((error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
sc->sc_address, cmdbuf, 1,
&ch, 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"strtc_read: read failed at 0x%x\n", a);
return (error);
}
if ((error = uiomove(&ch, 1, uio)) != 0) {
iic_release_bus(sc->sc_tag, 0);
return (error);
}
}
iic_release_bus(sc->sc_tag, 0);
return (0);
}
/*ARGSUSED*/
int
strtc_write(dev_t dev, struct uio *uio, int flags)
{
struct strtc_softc *sc;
u_int8_t cmdbuf[2];
int a, error;
if ((sc = device_lookup_private(&strtc_cd, minor(dev))) == NULL)
return (ENXIO);
const struct strtc_model * const sm = sc->sc_model;
if (uio->uio_offset >= sm->sm_nvram_size)
return (EINVAL);
if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
return (error);
while (uio->uio_resid && uio->uio_offset < sm->sm_nvram_size) {
a = (int)uio->uio_offset;
cmdbuf[0] = a + sm->sm_nvram_start;
if ((error = uiomove(&cmdbuf[1], 1, uio)) != 0)
break;
if ((error = iic_exec(sc->sc_tag,
uio->uio_resid ? I2C_OP_WRITE : I2C_OP_WRITE_WITH_STOP,
sc->sc_address, cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
aprint_error_dev(sc->sc_dev,
"strtc_write: write failed at 0x%x\n", a);
break;
}
}
iic_release_bus(sc->sc_tag, 0);
return (error);
}
static int
strtc_gettime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt)
{
struct strtc_softc *sc = ch->cookie;
struct clock_ymdhms check;
int retries, error;
memset(dt, 0, sizeof(*dt));
memset(&check, 0, sizeof(check));
/*
* Since we don't support Burst Read, we have to read the clock twice
* until we get two consecutive identical results.
*/
retries = 5;
do {
if ((error = strtc_clock_read(sc, dt)) == 0)
error = strtc_clock_read(sc, &check);
if (error)
return error;
} while (memcmp(dt, &check, sizeof(check)) != 0 && --retries);
return (0);
}
static int
strtc_clock_read(struct strtc_softc *sc, struct clock_ymdhms *dt)
{
u_int8_t bcd[M41ST84_REG_DATE_BYTES], cmdbuf[2];
int i, error;
if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
aprint_error_dev(sc->sc_dev,
"strtc_clock_read: failed to acquire I2C bus\n");
return (error);
}
/*
* Check for the HT bit -- if set, then clock lost power & stopped
* If that happened, then clear the bit so that the clock will have
* a chance to run again.
*/
cmdbuf[0] = M41ST84_REG_AL_HOUR;
if ((error = iic_exec(sc->sc_tag, I2C_OP_READ, sc->sc_address,
cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"strtc_clock_read: failed to read HT\n");
return (error);
}
if (cmdbuf[1] & M41ST84_AL_HOUR_HT) {
cmdbuf[1] &= ~M41ST84_AL_HOUR_HT;
if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE, sc->sc_address,
cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"strtc_clock_read: failed to reset HT\n");
return (error);
}
}
/* Read each RTC register in order. */
for (i = M41ST84_REG_CSEC; i < M41ST84_REG_DATE_BYTES; i++) {
cmdbuf[0] = i;
if ((error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
sc->sc_address, cmdbuf, 1,
&bcd[i], 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"strtc_clock_read: failed to read rtc "
"at 0x%x\n", i);
return (error);
}
}
/* Done with I2C */
iic_release_bus(sc->sc_tag, 0);
/*
* Convert the M41ST84's register values into something useable
*/
dt->dt_sec = bcdtobin(bcd[M41ST84_REG_SEC] & M41ST84_SEC_MASK);
dt->dt_min = bcdtobin(bcd[M41ST84_REG_MIN] & M41ST84_MIN_MASK);
dt->dt_hour = bcdtobin(bcd[M41ST84_REG_CENHR] & M41ST84_HOUR_MASK);
dt->dt_day = bcdtobin(bcd[M41ST84_REG_DATE] & M41ST84_DATE_MASK);
dt->dt_mon = bcdtobin(bcd[M41ST84_REG_MONTH] & M41ST84_MONTH_MASK);
/* XXX: Should be an MD way to specify EPOCH used by BIOS/Firmware */
/* XXX: Wait, isn't that what rtc_offset in todr_gettime() is for? */
dt->dt_year = bcdtobin(bcd[M41ST84_REG_YEAR]) + POSIX_BASE_YEAR;
return (0);
}
static int
strtc_settime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt)
{
struct strtc_softc *sc = ch->cookie;
uint8_t bcd[M41ST84_REG_DATE_BYTES], cmdbuf[2];
int i, error;
/*
* Convert our time representation into something the M41ST84
* can understand.
*/
bcd[M41ST84_REG_CSEC] = bintobcd(0); /* must always write as 0 */
bcd[M41ST84_REG_SEC] = bintobcd(dt->dt_sec);
bcd[M41ST84_REG_MIN] = bintobcd(dt->dt_min);
bcd[M41ST84_REG_CENHR] = bintobcd(dt->dt_hour);
bcd[M41ST84_REG_DATE] = bintobcd(dt->dt_day);
bcd[M41ST84_REG_DAY] = bintobcd(dt->dt_wday);
bcd[M41ST84_REG_MONTH] = bintobcd(dt->dt_mon);
bcd[M41ST84_REG_YEAR] = bintobcd((dt->dt_year - POSIX_BASE_YEAR) % 100);
if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
aprint_error_dev(sc->sc_dev,
"strtc_clock_write: failed to acquire I2C bus\n");
return (error);
}
/* Stop the clock */
cmdbuf[0] = M41ST84_REG_SEC;
cmdbuf[1] = M41ST84_SEC_ST;
if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE, sc->sc_address,
cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"strtc_clock_write: failed to Hold Clock\n");
return (error);
}
/*
* Check for the HT bit -- if set, then clock lost power & stopped
* If that happened, then clear the bit so that the clock will have
* a chance to run again.
*/
cmdbuf[0] = M41ST84_REG_AL_HOUR;
if ((error = iic_exec(sc->sc_tag, I2C_OP_READ, sc->sc_address,
cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"strtc_clock_write: failed to read HT\n");
return (error);
}
if (cmdbuf[1] & M41ST84_AL_HOUR_HT) {
cmdbuf[1] &= ~M41ST84_AL_HOUR_HT;
if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE, sc->sc_address,
cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"strtc_clock_write: failed to reset HT\n");
return (error);
}
}
/*
* Write registers in reverse order. The last write (to the Seconds
* register) will undo the Clock Hold, above.
*/
for (i = M41ST84_REG_DATE_BYTES - 1; i >= 0; i--) {
cmdbuf[0] = i;
if ((error = iic_exec(sc->sc_tag,
i ? I2C_OP_WRITE : I2C_OP_WRITE_WITH_STOP,
sc->sc_address, cmdbuf, 1, &bcd[i], 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"strtc_clock_write: failed to write rtc "
" at 0x%x\n", i);
/* XXX: Clock Hold is likely still asserted! */
return (error);
}
}
iic_release_bus(sc->sc_tag, 0);
return (0);
}
void
strtc_wdog_config(void *arg, uint8_t wd)
{
struct strtc_softc *sc = arg;
uint8_t cmdbuf[2];
if ((sc->sc_model->sm_flags & STRTC_F_HAS_WDOG) == 0) {
aprint_error_dev(sc->sc_dev,
"strtc_wdog_config: watchdog timer not present\n");
return;
}
if (iic_acquire_bus(sc->sc_tag, 0)) {
aprint_error_dev(sc->sc_dev,
"strtc_wdog_config: failed to acquire I2C bus\n");
return;
}
cmdbuf[0] = M41ST84_REG_WATCHDOG;
cmdbuf[1] = wd;
if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
cmdbuf, 1, &cmdbuf[1], 1, 0)) {
aprint_error_dev(sc->sc_dev,
"strtc_wdog_config: failed to write watchdog\n");
return;
}
iic_release_bus(sc->sc_tag, 0);
}