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freebsd-nq/sys/dev/iicbus/nxprtc.c

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/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2017 Ian Lepore <ian@freebsd.org>
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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>
__FBSDID("$FreeBSD$");
/*
* Driver for NXP real-time clock/calendar chips:
* - PCF8563 = low power, countdown timer
* - PCA8565 = like PCF8563, automotive temperature range
* - PCF8523 = low power, countdown timer, oscillator freq tuning, 2 timers
* - PCF2127 = like PCF8523, industrial, tcxo, tamper/ts, i2c & spi, 512B ram
* - PCA2129 = like PCF8523, automotive, tcxo, tamper/ts, i2c & spi, (note 1)
* - PCF2129 = like PCF8523, industrial, tcxo, tamper/ts, i2c & spi, (note 1)
*
* Most chips have a countdown timer, ostensibly intended to generate periodic
* interrupt signals on an output pin. The timer is driven from the same
* divider chain that clocks the time of day registers, and they start counting
* in sync when the STOP bit is cleared after the time and timer registers are
* set. The timer register can also be read on the fly, so we use it to count
* fractional seconds and get a resolution of ~15ms.
*
* [1] Note that the datasheets for the PCx2129 chips state that they have only
* a watchdog timer, not a countdown timer. Empirical testing shows that the
* countdown timer is actually there and it works fine, except that it can't
* trigger an interrupt or toggle an output pin like it can on other chips. We
* don't care about interrupts and output pins, we just read the timer register
* to get better resolution.
*/
#include "opt_platform.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/clock.h>
#include <sys/kernel.h>
#include <sys/libkern.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>
#ifdef FDT
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif
#include "clock_if.h"
#include "iicbus_if.h"
/*
* I2C address 1010 001x : PCA2129 PCF2127 PCF2129 PCF8563 PCF8565
* I2C address 1101 000x : PCF8523
*/
#define PCF8563_ADDR 0xa2
#define PCF8523_ADDR 0xd0
/*
* Registers, bits within them, and masks that are common to all chip types.
*/
#define PCF85xx_R_CS1 0x00 /* CS1 and CS2 control regs are in */
#define PCF85xx_R_CS2 0x01 /* the same location on all chips. */
#define PCF85xx_B_CS1_STOP 0x20 /* Stop time incrementing bit */
#define PCF85xx_B_SECOND_OS 0x80 /* Oscillator Stopped bit */
#define PCF85xx_M_SECOND 0x7f /* Masks for all BCD time regs... */
#define PCF85xx_M_MINUTE 0x7f
#define PCF85xx_M_12HOUR 0x1f
#define PCF85xx_M_24HOUR 0x3f
#define PCF85xx_M_DAY 0x3f
#define PCF85xx_M_MONTH 0x1f
#define PCF85xx_M_YEAR 0xff
/*
* PCF2127-specific registers, bits, and masks.
*/
#define PCF2127_R_TMR_CTL 0x10 /* Timer/watchdog control */
#define PCF2127_M_TMR_CTRL 0xe3 /* Mask off undef bits */
#define PCF2127_B_TMR_CD 0x40 /* Run in countdown mode */
#define PCF2127_B_TMR_64HZ 0x01 /* Timer frequency 64Hz */
#define PCF2127_R_TS_CTL 0x12 /* Timestamp control */
#define PCF2127_B_TSOFF 0x40 /* Turn off timestamp function */
#define PCF2127_R_AGING_OFFSET 0x19 /* Frequency aging offset in PPM */
/*
* PCA/PCF2129-specific registers, bits, and masks.
*/
#define PCF2129_B_CS1_12HR 0x04 /* Use 12-hour (AM/PM) mode bit */
#define PCF2129_B_CLKOUT_OTPR 0x20 /* OTP refresh command */
#define PCF2129_B_CLKOUT_HIGHZ 0x07 /* Clock Out Freq = disable */
/*
* PCF8523-specific registers, bits, and masks.
*/
#define PCF8523_R_CS3 0x02 /* Control and status reg 3 */
#define PCF8523_R_SECOND 0x03 /* Seconds */
#define PCF8523_R_TMR_CLKOUT 0x0F /* Timer and clockout control */
#define PCF8523_R_TMR_A_FREQ 0x10 /* Timer A frequency control */
#define PCF8523_R_TMR_A_COUNT 0x11 /* Timer A count */
#define PCF8523_M_TMR_A_FREQ 0x07 /* Mask off undef bits */
#define PCF8523_B_HOUR_PM 0x20 /* PM bit */
#define PCF8523_B_CS1_SOFTRESET 0x58 /* Initiate Soft Reset bits */
#define PCF8523_B_CS1_12HR 0x08 /* Use 12-hour (AM/PM) mode bit */
#define PCF8523_B_CLKOUT_TACD 0x02 /* TimerA runs in CountDown mode */
#define PCF8523_B_CLKOUT_HIGHZ 0x38 /* Clock Out Freq = disable */
#define PCF8523_B_TMR_A_64HZ 0x01 /* Timer A freq 64Hz */
#define PCF8523_M_CS3_PM 0xE0 /* Power mode mask */
#define PCF8523_B_CS3_PM_NOBAT 0xE0 /* PM bits: no battery usage */
#define PCF8523_B_CS3_PM_STD 0x00 /* PM bits: standard */
#define PCF8523_B_CS3_PM_DSNBM 0xa0 /* PM bits: direct switch, no bat mon */
#define PCF8523_B_CS3_BLF 0x04 /* Battery Low Flag bit */
/*
* PCF8563-specific registers, bits, and masks.
*/
#define PCF8563_R_SECOND 0x02 /* Seconds */
#define PCF8563_R_CLKOUT 0x0d /* Clock output control */
#define PCF8563_R_TMR_CTRL 0x0e /* Timer control */
#define PCF8563_R_TMR_COUNT 0x0f /* Timer count */
#define PCF8563_M_TMR_CTRL 0x93 /* Mask off undef bits */
#define PCF8563_B_TMR_ENABLE 0x80 /* Enable countdown timer */
#define PCF8563_B_TMR_64HZ 0x01 /* Timer frequency 64Hz */
#define PCF8563_B_MONTH_C 0x80 /* Century bit */
/*
* We use the countdown timer for fractional seconds. We program it for 64 Hz,
* the fastest available rate that doesn't roll over in less than a second.
*/
#define TMR_TICKS_SEC 64
#define TMR_TICKS_HALFSEC 32
/*
* The chip types we support.
*/
enum {
TYPE_NONE,
TYPE_PCA2129,
TYPE_PCA8565,
TYPE_PCF2127,
TYPE_PCF2129,
TYPE_PCF8523,
TYPE_PCF8563,
TYPE_COUNT
};
static const char *desc_strings[] = {
"",
"NXP PCA2129 RTC",
"NXP PCA8565 RTC",
"NXP PCF2127 RTC",
"NXP PCF2129 RTC",
"NXP PCF8523 RTC",
"NXP PCF8563 RTC",
};
CTASSERT(nitems(desc_strings) == TYPE_COUNT);
/*
* The time registers in the order they are laid out in hardware.
*/
struct time_regs {
uint8_t sec, min, hour, day, wday, month, year;
};
struct nxprtc_softc {
device_t dev;
device_t busdev;
struct intr_config_hook
config_hook;
u_int flags; /* SC_F_* flags */
u_int chiptype; /* Type of PCF85xx chip */
time_t bat_time; /* Next time to check battery */
int freqadj; /* Current freq adj in PPM */
uint8_t secaddr; /* Address of seconds register */
uint8_t tmcaddr; /* Address of timer count register */
bool use_timer; /* Use timer for fractional sec */
bool use_ampm; /* Chip is set to use am/pm mode */
bool is212x; /* Chip type is 2127 or 2129 */
};
#define SC_F_CPOL (1 << 0) /* Century bit means 19xx */
/*
* When doing i2c IO, indicate that we need to wait for exclusive bus ownership,
* but that we should not wait if we already own the bus. This lets us put
* iicbus_acquire_bus() calls with a non-recursive wait at the entry of our API
* functions to ensure that only one client at a time accesses the hardware for
* the entire series of operations it takes to read or write the clock.
*/
#define WAITFLAGS (IIC_WAIT | IIC_RECURSIVE)
/*
* We use the compat_data table to look up hint strings in the non-FDT case, so
* define the struct locally when we don't get it from ofw_bus_subr.h.
*/
#ifdef FDT
typedef struct ofw_compat_data nxprtc_compat_data;
#else
typedef struct {
const char *ocd_str;
uintptr_t ocd_data;
} nxprtc_compat_data;
#endif
static nxprtc_compat_data compat_data[] = {
{"nxp,pca2129", TYPE_PCA2129},
{"nxp,pca8565", TYPE_PCA8565},
{"nxp,pcf2127", TYPE_PCF2127},
{"nxp,pcf2129", TYPE_PCF2129},
{"nxp,pcf8523", TYPE_PCF8523},
{"nxp,pcf8563", TYPE_PCF8563},
/* Undocumented compat strings known to exist in the wild... */
{"pcf8563", TYPE_PCF8563},
{"phg,pcf8563", TYPE_PCF8563},
{"philips,pcf8563", TYPE_PCF8563},
{NULL, TYPE_NONE},
};
static int
nxprtc_readfrom(device_t slavedev, uint8_t regaddr, void *buffer,
uint16_t buflen, int waithow)
{
struct iic_msg msg;
int err;
uint8_t slaveaddr;
/*
* Two transfers back to back with a stop and start between them; first we
* write the address-within-device, then we read from the device. This
* is used instead of the standard iicdev_readfrom() because some of the
* chips we service don't support i2c repeat-start operations (grrrrr)
* so we do two completely separate transfers with a full stop between.
*/
slaveaddr = iicbus_get_addr(slavedev);
msg.slave = slaveaddr;
msg.flags = IIC_M_WR;
msg.len = 1;
msg.buf = &regaddr;
if ((err = iicbus_transfer_excl(slavedev, &msg, 1, waithow)) != 0)
return (err);
msg.slave = slaveaddr;
msg.flags = IIC_M_RD;
msg.len = buflen;
msg.buf = buffer;
return (iicbus_transfer_excl(slavedev, &msg, 1, waithow));
}
static int
read_reg(struct nxprtc_softc *sc, uint8_t reg, uint8_t *val)
{
return (nxprtc_readfrom(sc->dev, reg, val, sizeof(*val), WAITFLAGS));
}
static int
write_reg(struct nxprtc_softc *sc, uint8_t reg, uint8_t val)
{
return (iicdev_writeto(sc->dev, reg, &val, sizeof(val), WAITFLAGS));
}
static int
read_timeregs(struct nxprtc_softc *sc, struct time_regs *tregs, uint8_t *tmr)
{
int err;
uint8_t sec, tmr1, tmr2;
/*
* The datasheet says loop to read the same timer value twice because it
* does not freeze while reading. To that we add our own logic that
* the seconds register must be the same before and after reading the
* timer, ensuring the fractional part is from the same second as tregs.
*/
do {
if (sc->use_timer) {
if ((err = read_reg(sc, sc->secaddr, &sec)) != 0)
break;
if ((err = read_reg(sc, sc->tmcaddr, &tmr1)) != 0)
break;
if ((err = read_reg(sc, sc->tmcaddr, &tmr2)) != 0)
break;
if (tmr1 != tmr2)
continue;
}
if ((err = nxprtc_readfrom(sc->dev, sc->secaddr, tregs,
sizeof(*tregs), WAITFLAGS)) != 0)
break;
} while (sc->use_timer && tregs->sec != sec);
/*
* If the timer value is greater than our hz rate (or is zero),
* something is wrong. Maybe some other OS used the timer differently?
* Just set it to zero. Likewise if we're not using the timer. After
* the offset calc below, the zero turns into 32, the mid-second point,
* which in effect performs 4/5 rounding, which is just the right thing
* to do if we don't have fine-grained time.
*/
if (!sc->use_timer || tmr1 > TMR_TICKS_SEC)
tmr1 = 0;
/*
* Turn the downcounter into an upcounter. The timer starts counting at
* and rolls over at mid-second, so add half a second worth of ticks to
* get its zero point back in sync with the tregs.sec rollover.
*/
*tmr = (TMR_TICKS_SEC - tmr1 + TMR_TICKS_HALFSEC) % TMR_TICKS_SEC;
return (err);
}
static int
write_timeregs(struct nxprtc_softc *sc, struct time_regs *tregs)
{
return (iicdev_writeto(sc->dev, sc->secaddr, tregs,
sizeof(*tregs), WAITFLAGS));
}
static int
freqadj_sysctl(SYSCTL_HANDLER_ARGS)
{
struct nxprtc_softc *sc;
int err, freqppm, newppm;
sc = arg1;
/* PPM range [-7,8] maps to reg value range [0,15] */
freqppm = newppm = 8 - sc->freqadj;
err = sysctl_handle_int(oidp, &newppm, 0, req);
if (err != 0 || req->newptr == NULL)
return (err);
if (freqppm != newppm) {
if (newppm < -7 || newppm > 8)
return (EINVAL);
sc->freqadj = 8 - newppm;
err = write_reg(sc, PCF2127_R_AGING_OFFSET, sc->freqadj);
}
return (err);
}
static int
pcf8523_battery_check(struct nxprtc_softc *sc)
{
struct timespec ts;
int err;
uint8_t cs3;
/* We check the battery when starting up, and then only once a day. */
getnanouptime(&ts);
if (ts.tv_sec < sc->bat_time)
return (0);
sc->bat_time = ts.tv_sec + (60 * 60 * 24);
/*
* The 8523, 2127, and 2129 chips have a "power manager" which includes
* an optional battery voltage monitor and several choices for power
* switching modes. The battery monitor uses a lot of current and it
* remains active when running from battery, making it the "drain my
* battery twice as fast" mode. So, we run the chip in direct-switching
* mode with the battery monitor disabled, reducing the current draw
* when running on battery from 1930nA to 880nA. While it's not clear
* from the datasheets, empirical testing shows that both disabling the
* battery monitor and using direct-switch mode are required to get the
* full power savings.
*
* There isn't any need to continuously monitor the battery voltage, so
* this function is used to periodically enable the monitor, check the
* voltage, then return to the low-power monitor-disabled mode.
*/
err = write_reg(sc, PCF8523_R_CS3, PCF8523_B_CS3_PM_STD);
if (err != 0) {
device_printf(sc->dev, "cannot write CS3 reg\n");
return (err);
}
pause_sbt("nxpbat", mstosbt(10), 0, 0);
if ((err = read_reg(sc, PCF8523_R_CS3, &cs3)) != 0) {
device_printf(sc->dev, "cannot read CS3 reg\n");
return (err);
}
err = write_reg(sc, PCF8523_R_CS3, PCF8523_B_CS3_PM_DSNBM);
if (err != 0) {
device_printf(sc->dev, "cannot write CS3 reg\n");
return (err);
}
if (cs3 & PCF8523_B_CS3_BLF)
device_printf(sc->dev, "WARNING: RTC battery is low\n");
return (0);
}
static int
pcf8523_start(struct nxprtc_softc *sc)
{
struct sysctl_ctx_list *ctx;
struct sysctl_oid_list *tree;
struct csr {
uint8_t cs1;
uint8_t cs2;
uint8_t cs3;
uint8_t sec;
} csr;
int err;
uint8_t clkout, freqadj;
/* Read the control and status registers. */
if ((err = nxprtc_readfrom(sc->dev, PCF85xx_R_CS1, &csr,
sizeof(csr), WAITFLAGS)) != 0){
device_printf(sc->dev, "cannot read RTC control regs\n");
return (err);
}
/*
* Do a full init if...
* - The chip power manager is in battery-disable mode.
* - The OS (oscillator stopped) bit is set (all power was lost).
* - The clock-increment STOP flag is set (this is just insane).
*/
if ((csr.cs3 & PCF8523_M_CS3_PM) == PCF8523_B_CS3_PM_NOBAT ||
(csr.cs1 & PCF85xx_B_CS1_STOP) || (csr.sec & PCF85xx_B_SECOND_OS)) {
device_printf(sc->dev,
"WARNING: RTC battery failed; time is invalid\n");
/*
* For 212x series...
* - Turn off the POR-Override bit (used for mfg test only),
* by writing zero to cs 1 (all other bits power on as zero).
* - Turn off the timestamp option to save the power used to
* monitor that input pin.
* - Trigger OTP refresh by forcing the OTPR bit to zero then
* back to 1, then wait 100ms for the refresh.
*/
if (sc->is212x) {
err = write_reg(sc, PCF85xx_R_CS1, 0);
if (err != 0) {
device_printf(sc->dev,
"cannot write CS1 reg\n");
return (err);
}
err = write_reg(sc, PCF2127_R_TS_CTL, PCF2127_B_TSOFF);
if (err != 0) {
device_printf(sc->dev,
"cannot write timestamp control\n");
return (err);
}
clkout = PCF2129_B_CLKOUT_HIGHZ;
err = write_reg(sc, PCF8523_R_TMR_CLKOUT, clkout);
if (err == 0)
err = write_reg(sc, PCF8523_R_TMR_CLKOUT,
clkout | PCF2129_B_CLKOUT_OTPR);
if (err != 0) {
device_printf(sc->dev,
"cannot write CLKOUT control\n");
return (err);
}
pause_sbt("nxpotp", mstosbt(100), mstosbt(10), 0);
} else
clkout = PCF8523_B_CLKOUT_HIGHZ;
/* All chips: set clock output pin to high-z to save power */
if ((err = write_reg(sc, PCF8523_R_TMR_CLKOUT, clkout)) != 0) {
device_printf(sc->dev, "cannot write CLKOUT control\n");
return (err);
}
}
/*
* Check the battery voltage and report if it's low. This also has the
* side effect of (re-)initializing the power manager to low-power mode
* when we come up after a power fail.
*/
pcf8523_battery_check(sc);
/*
* Remember whether we're running in AM/PM mode. The chip default is
* 24-hour mode, but if we're co-existing with some other OS that
* prefers AM/PM we can run that way too.
*
* Also, for 212x chips, retrieve the current frequency aging offset,
* and set up the sysctl handler for reading/setting it.
*/
if (sc->is212x) {
if (csr.cs1 & PCF2129_B_CS1_12HR)
sc->use_ampm = true;
err = read_reg(sc, PCF2127_R_AGING_OFFSET, &freqadj);
if (err != 0) {
device_printf(sc->dev,
"cannot read AGINGOFFSET register\n");
return (err);
}
sc->freqadj = (int8_t)freqadj;
ctx = device_get_sysctl_ctx(sc->dev);
tree = SYSCTL_CHILDREN(device_get_sysctl_tree(sc->dev));
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "freqadj",
CTLFLAG_RWTUN | CTLTYPE_INT | CTLFLAG_MPSAFE, sc, 0,
freqadj_sysctl, "I", "Frequency adjust in PPM, range [-7,+8]");
} else {
if (csr.cs1 & PCF8523_B_CS1_12HR)
sc->use_ampm = true;
}
return (0);
}
static int
pcf8523_start_timer(struct nxprtc_softc *sc)
{
int err;
uint8_t clkout, stdclk, stdfreq, tmrfreq;
/*
* Read the timer control and frequency regs. If they don't have the
* values we normally program into them then the timer count doesn't
* contain a valid fractional second, so zero it to prevent using a bad
* value. Then program the normal timer values so that on the first
* settime call we'll begin to use fractional time.
*/
if ((err = read_reg(sc, PCF8523_R_TMR_A_FREQ, &tmrfreq)) != 0)
return (err);
if ((err = read_reg(sc, PCF8523_R_TMR_CLKOUT, &clkout)) != 0)
return (err);
stdfreq = PCF8523_B_TMR_A_64HZ;
stdclk = PCF8523_B_CLKOUT_TACD | PCF8523_B_CLKOUT_HIGHZ;
if (clkout != stdclk || (tmrfreq & PCF8523_M_TMR_A_FREQ) != stdfreq) {
if ((err = write_reg(sc, sc->tmcaddr, 0)) != 0)
return (err);
if ((err = write_reg(sc, PCF8523_R_TMR_A_FREQ, stdfreq)) != 0)
return (err);
if ((err = write_reg(sc, PCF8523_R_TMR_CLKOUT, stdclk)) != 0)
return (err);
}
return (0);
}
static int
pcf2127_start_timer(struct nxprtc_softc *sc)
{
int err;
uint8_t stdctl, tmrctl;
/*
* Set up timer if it's not already in the mode we normally run it. See
* the comment in pcf8523_start_timer() for more details.
*
* Note that the PCF2129 datasheet says it has no countdown timer, but
* empirical testing shows that it works just fine for our purposes.
*/
if ((err = read_reg(sc, PCF2127_R_TMR_CTL, &tmrctl)) != 0)
return (err);
stdctl = PCF2127_B_TMR_CD | PCF8523_B_TMR_A_64HZ;
if ((tmrctl & PCF2127_M_TMR_CTRL) != stdctl) {
if ((err = write_reg(sc, sc->tmcaddr, 0)) != 0)
return (err);
if ((err = write_reg(sc, PCF2127_R_TMR_CTL, stdctl)) != 0)
return (err);
}
return (0);
}
static int
pcf8563_start(struct nxprtc_softc *sc)
{
struct csr {
uint8_t cs1;
uint8_t cs2;
uint8_t sec;
} csr;
int err;
/* Read the control and status registers. */
if ((err = nxprtc_readfrom(sc->dev, PCF85xx_R_CS1, &csr,
sizeof(csr), WAITFLAGS)) != 0){
device_printf(sc->dev, "cannot read RTC control regs\n");
return (err);
}
/*
* Do a full init if...
* - The OS (oscillator stopped) bit is set (all power was lost). This
* bit is called VL (Voltage Low) in the 8563 datasheet.
* - The clock-increment STOP flag is set (this is just insane).
*/
if ((csr.cs1 & PCF85xx_B_CS1_STOP) || (csr.sec & PCF85xx_B_SECOND_OS)) {
device_printf(sc->dev,
"WARNING: RTC battery failed; time is invalid\n");
/*
* - Turn off the POR-Override bit (used for mfg test only), by
* writing zero to cs 1 (all other bits power on as zero).
* - Turn off the clock output pin (to save battery power), by
* writing zero to the clkout control reg.
*/
if ((err = write_reg(sc, PCF85xx_R_CS1, 0)) != 0) {
device_printf(sc->dev, "cannot write CS1 reg\n");
return (err);
}
if ((err = write_reg(sc, PCF8563_R_CLKOUT, 0)) != 0) {
device_printf(sc->dev, "cannot write CS1 reg\n");
return (err);
}
}
return (0);
}
static int
pcf8563_start_timer(struct nxprtc_softc *sc)
{
int err;
uint8_t stdctl, tmrctl;
/* See comment in pcf8523_start_timer(). */
if ((err = read_reg(sc, PCF8563_R_TMR_CTRL, &tmrctl)) != 0)
return (err);
stdctl = PCF8563_B_TMR_ENABLE | PCF8563_B_TMR_64HZ;
if ((tmrctl & PCF8563_M_TMR_CTRL) != stdctl) {
if ((err = write_reg(sc, sc->tmcaddr, 0)) != 0)
return (err);
if ((err = write_reg(sc, PCF8563_R_TMR_CTRL, stdctl)) != 0)
return (err);
}
return (0);
}
static void
nxprtc_start(void *dev)
{
struct nxprtc_softc *sc;
int clockflags, resolution;
sc = device_get_softc((device_t)dev);
config_intrhook_disestablish(&sc->config_hook);
/* First do chip-specific inits. */
switch (sc->chiptype) {
case TYPE_PCA2129:
case TYPE_PCF2129:
case TYPE_PCF2127:
sc->is212x = true;
if (pcf8523_start(sc) != 0)
return;
if (pcf2127_start_timer(sc) != 0) {
device_printf(sc->dev, "cannot set up timer\n");
return;
}
break;
case TYPE_PCF8523:
if (pcf8523_start(sc) != 0)
return;
if (pcf8523_start_timer(sc) != 0) {
device_printf(sc->dev, "cannot set up timer\n");
return;
}
break;
case TYPE_PCA8565:
case TYPE_PCF8563:
if (pcf8563_start(sc) != 0)
return;
if (pcf8563_start_timer(sc) != 0) {
device_printf(sc->dev, "cannot set up timer\n");
return;
}
break;
default:
device_printf(sc->dev, "missing init code for this chiptype\n");
return;
}
/*
* Everything looks good if we make it to here; register as an RTC. If
* we're using the timer to count fractional seconds, our resolution is
* 1e6/64, about 15.6ms. Without the timer we still align the RTC clock
* when setting it so our error is an average .5s when reading it.
* Schedule our clock_settime() method to be called at a .495ms offset
* into the second, because the clock hardware resets the divider chain
* to the mid-second point when you set the time and it takes about 5ms
* of i2c bus activity to set the clock.
*/
resolution = sc->use_timer ? 1000000 / TMR_TICKS_SEC : 1000000 / 2;
clockflags = CLOCKF_GETTIME_NO_ADJ | CLOCKF_SETTIME_NO_TS;
clock_register_flags(sc->dev, resolution, clockflags);
clock_schedule(sc->dev, 495000000);
}
static int
nxprtc_gettime(device_t dev, struct timespec *ts)
{
struct bcd_clocktime bct;
struct time_regs tregs;
struct nxprtc_softc *sc;
int err;
uint8_t cs1, hourmask, tmrcount;
sc = device_get_softc(dev);
/*
* Read the time, but before using it, validate that the oscillator-
* stopped/power-fail bit is not set, and that the time-increment STOP
* bit is not set in the control reg. The latter can happen if there
* was an error when setting the time.
*/
if ((err = iicbus_request_bus(sc->busdev, sc->dev, IIC_WAIT)) == 0) {
if ((err = read_timeregs(sc, &tregs, &tmrcount)) == 0) {
err = read_reg(sc, PCF85xx_R_CS1, &cs1);
}
iicbus_release_bus(sc->busdev, sc->dev);
}
if (err != 0)
return (err);
if ((tregs.sec & PCF85xx_B_SECOND_OS) || (cs1 & PCF85xx_B_CS1_STOP)) {
device_printf(dev, "RTC clock not running\n");
return (EINVAL); /* hardware is good, time is not. */
}
if (sc->use_ampm)
hourmask = PCF85xx_M_12HOUR;
else
hourmask = PCF85xx_M_24HOUR;
bct.nsec = ((uint64_t)tmrcount * 1000000000) / TMR_TICKS_SEC;
bct.ispm = (tregs.hour & PCF8523_B_HOUR_PM) != 0;
bct.sec = tregs.sec & PCF85xx_M_SECOND;
bct.min = tregs.min & PCF85xx_M_MINUTE;
bct.hour = tregs.hour & hourmask;
bct.day = tregs.day & PCF85xx_M_DAY;
bct.mon = tregs.month & PCF85xx_M_MONTH;
bct.year = tregs.year & PCF85xx_M_YEAR;
/*
* Old PCF8563 datasheets recommended that the C bit be 1 for 19xx and 0
* for 20xx; newer datasheets don't recommend that. We don't care,
* but we may co-exist with other OSes sharing the hardware. Determine
* existing polarity on a read so that we can preserve it on a write.
*/
if (sc->chiptype == TYPE_PCF8563) {
if (tregs.month & PCF8563_B_MONTH_C) {
if (bct.year < 0x70)
sc->flags |= SC_F_CPOL;
} else if (bct.year >= 0x70)
sc->flags |= SC_F_CPOL;
}
clock_dbgprint_bcd(sc->dev, CLOCK_DBG_READ, &bct);
err = clock_bcd_to_ts(&bct, ts, sc->use_ampm);
ts->tv_sec += utc_offset();
return (err);
}
static int
nxprtc_settime(device_t dev, struct timespec *ts)
{
struct bcd_clocktime bct;
struct time_regs tregs;
struct nxprtc_softc *sc;
int err;
uint8_t cflag, cs1;
sc = device_get_softc(dev);
/*
* We stop the clock, set the time, then restart the clock. Half a
* second after restarting the clock it ticks over to the next second.
* So to align the RTC, we schedule this function to be called when
* system time is roughly halfway (.495) through the current second.
*
* Reserve use of the i2c bus and stop the RTC clock. Note that if
* anything goes wrong from this point on, we leave the clock stopped,
* because we don't really know what state it's in.
*/
if ((err = iicbus_request_bus(sc->busdev, sc->dev, IIC_WAIT)) != 0)
return (err);
if ((err = read_reg(sc, PCF85xx_R_CS1, &cs1)) != 0)
goto errout;
cs1 |= PCF85xx_B_CS1_STOP;
if ((err = write_reg(sc, PCF85xx_R_CS1, cs1)) != 0)
goto errout;
/* Grab a fresh post-sleep idea of what time it is. */
getnanotime(ts);
ts->tv_sec -= utc_offset();
ts->tv_nsec = 0;
clock_ts_to_bcd(ts, &bct, sc->use_ampm);
clock_dbgprint_bcd(sc->dev, CLOCK_DBG_WRITE, &bct);
/* On 8563 set the century based on the polarity seen when reading. */
cflag = 0;
if (sc->chiptype == TYPE_PCF8563) {
if ((sc->flags & SC_F_CPOL) != 0) {
if (bct.year >= 0x2000)
cflag = PCF8563_B_MONTH_C;
} else if (bct.year < 0x2000)
cflag = PCF8563_B_MONTH_C;
}
tregs.sec = bct.sec;
tregs.min = bct.min;
tregs.hour = bct.hour | (bct.ispm ? PCF8523_B_HOUR_PM : 0);
tregs.day = bct.day;
tregs.month = bct.mon;
tregs.year = (bct.year & 0xff) | cflag;
tregs.wday = bct.dow;
/*
* Set the time, reset the timer count register, then start the clocks.
*/
if ((err = write_timeregs(sc, &tregs)) != 0)
goto errout;
if ((err = write_reg(sc, sc->tmcaddr, TMR_TICKS_SEC)) != 0)
return (err);
cs1 &= ~PCF85xx_B_CS1_STOP;
err = write_reg(sc, PCF85xx_R_CS1, cs1);
/*
* Check for battery-low. The actual check is throttled to only occur
* once a day, mostly to avoid spamming the user with frequent warnings.
*/
pcf8523_battery_check(sc);
errout:
iicbus_release_bus(sc->busdev, sc->dev);
if (err != 0)
device_printf(dev, "cannot write RTC time\n");
return (err);
}
static int
nxprtc_get_chiptype(device_t dev)
{
#ifdef FDT
return (ofw_bus_search_compatible(dev, compat_data)->ocd_data);
#else
nxprtc_compat_data *cdata;
const char *htype;
int chiptype;
/*
* If given a chiptype hint string, loop through the ofw compat data
* comparing the hinted chip type to the compat strings. The table end
* marker ocd_data is TYPE_NONE.
*/
if (resource_string_value(device_get_name(dev),
device_get_unit(dev), "compatible", &htype) == 0) {
for (cdata = compat_data; cdata->ocd_str != NULL; ++cdata) {
if (strcmp(htype, cdata->ocd_str) == 0)
break;
}
chiptype = cdata->ocd_data;
} else
chiptype = TYPE_NONE;
/*
* On non-FDT systems the historical behavior of this driver was to
* assume a PCF8563; keep doing that for compatibility.
*/
if (chiptype == TYPE_NONE)
return (TYPE_PCF8563);
else
return (chiptype);
#endif
}
static int
nxprtc_probe(device_t dev)
{
int chiptype, rv;
#ifdef FDT
if (!ofw_bus_status_okay(dev))
return (ENXIO);
rv = BUS_PROBE_GENERIC;
#else
rv = BUS_PROBE_NOWILDCARD;
#endif
if ((chiptype = nxprtc_get_chiptype(dev)) == TYPE_NONE)
return (ENXIO);
device_set_desc(dev, desc_strings[chiptype]);
return (rv);
}
static int
nxprtc_attach(device_t dev)
{
struct nxprtc_softc *sc;
sc = device_get_softc(dev);
sc->dev = dev;
sc->busdev = device_get_parent(dev);
/* We need to know what kind of chip we're driving. */
sc->chiptype = nxprtc_get_chiptype(dev);
/* The features and some register addresses vary by chip type. */
switch (sc->chiptype) {
case TYPE_PCA2129:
case TYPE_PCF2129:
case TYPE_PCF2127:
case TYPE_PCF8523:
sc->secaddr = PCF8523_R_SECOND;
sc->tmcaddr = PCF8523_R_TMR_A_COUNT;
sc->use_timer = true;
break;
case TYPE_PCA8565:
case TYPE_PCF8563:
sc->secaddr = PCF8563_R_SECOND;
sc->tmcaddr = PCF8563_R_TMR_COUNT;
sc->use_timer = true;
break;
default:
device_printf(dev, "impossible: cannot determine chip type\n");
return (ENXIO);
}
/*
* We have to wait until interrupts are enabled. Sometimes I2C read
* and write only works when the interrupts are available.
*/
sc->config_hook.ich_func = nxprtc_start;
sc->config_hook.ich_arg = dev;
if (config_intrhook_establish(&sc->config_hook) != 0)
return (ENOMEM);
return (0);
}
static int
nxprtc_detach(device_t dev)
{
clock_unregister(dev);
return (0);
}
static device_method_t nxprtc_methods[] = {
DEVMETHOD(device_probe, nxprtc_probe),
DEVMETHOD(device_attach, nxprtc_attach),
DEVMETHOD(device_detach, nxprtc_detach),
DEVMETHOD(clock_gettime, nxprtc_gettime),
DEVMETHOD(clock_settime, nxprtc_settime),
DEVMETHOD_END
};
static driver_t nxprtc_driver = {
"nxprtc",
nxprtc_methods,
sizeof(struct nxprtc_softc),
};
static devclass_t nxprtc_devclass;
DRIVER_MODULE(nxprtc, iicbus, nxprtc_driver, nxprtc_devclass, NULL, NULL);
MODULE_VERSION(nxprtc, 1);
MODULE_DEPEND(nxprtc, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
IICBUS_FDT_PNP_INFO(compat_data);
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