/*	$NetBSD: pcf8583.c,v 1.22 2026/10/29 17:43:54 jdc 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.
 */

/*
 * Driver for the Philips PCF8583 Real Time Clock.
 *
 * This driver is partially derived from Ben Harris's PCF8583 driver
 * for NetBSD/acorn26.
 *
 * Additional code written by Dave Tyson to support dual addressing 0x50/0x51
 * and to select chip operating mode using optional flag in kernel config.
 * Default with no flag set or flag 0 is existing TOD clock mode, flag 1 sets
 * 50hz input (TOD clock), flag 2 sets counter mode, flag 3 sets test mode.
 *
 * Setting counter mode provides an envsys variable mapped to the counter and
 * exposes a hw syctl variable which can set to 1 to zero the counter registers
 * after the next envstat call. 
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pcf8583.c,v 1.22 2026/10/29 17:43:54 jdc Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/sysctl.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/pcf8583reg.h>
#include <dev/i2c/pcf8583var.h>
#include <dev/sysmon/sysmonvar.h>

#include "ioconf.h"

struct pcfrtc_softc {
	device_t sc_dev;
	i2c_tag_t sc_tag;
	int sc_address;
	int sc_open;
	struct todr_chip_handle sc_todr;
	struct sysmon_envsys *sc_sme;
	envsys_data_t sc_counter;
	struct sysctllog *sc_pcfrtclog;
	int reset_counter;
};

static int  pcfrtc_match(device_t, cfdata_t, void *);
static void pcfrtc_attach(device_t, device_t, void *);
static int pcfrtc_sysctl_setup(struct pcfrtc_softc *sc);

CFATTACH_DECL_NEW(pcfrtc, sizeof(struct pcfrtc_softc),
	pcfrtc_match, pcfrtc_attach, NULL, NULL);

dev_type_open(pcfrtc_open);
dev_type_close(pcfrtc_close);
dev_type_read(pcfrtc_read);
dev_type_write(pcfrtc_write);

const struct cdevsw pcfrtc_cdevsw = {
	.d_open = pcfrtc_open,
	.d_close = pcfrtc_close,
	.d_read = pcfrtc_read,
	.d_write = pcfrtc_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 pcfrtc_clock_read(struct pcfrtc_softc *, struct clock_ymdhms *,
			     uint8_t *);
static int pcfrtc_clock_write(struct pcfrtc_softc *, struct clock_ymdhms *,
			      uint8_t);
static int pcfrtc_gettime(struct todr_chip_handle *, struct timeval *);
static int pcfrtc_settime(struct todr_chip_handle *, struct timeval *);
static void pcfrtc_readcount(struct sysmon_envsys *, envsys_data_t *) ;
static int pcfrtc_sysctl_check(SYSCTLFN_ARGS);

int
pcfrtc_match(device_t parent, cfdata_t cf, void *aux)
{
	struct i2c_attach_args *ia = aux;

	if ((ia->ia_addr & PCF8583_ADDRMASK) == PCF8583_ADDR ||
	    (ia->ia_addr & PCF8583_ADDRMASK) == PCF8583_ADDR2)
		return (I2C_MATCH_ADDRESS_ONLY);

	return (0);
}

void
pcfrtc_attach(device_t parent, device_t self, void *aux)
{
	struct pcfrtc_softc *sc = device_private(self);
	struct cfdata *cf = device_cfdata(self);
	struct i2c_attach_args *ia = aux;
	uint8_t cmdbuf[1], csr, mode;
	int error;

	sc->sc_tag = ia->ia_tag;
	sc->sc_address = ia->ia_addr;
	sc->sc_dev = self;

	/* if flags set & !zero then need to change device mode */

	if (cf->cf_flags != 0) {
		mode = cf->cf_flags << 4 & PCF8583_CSR_FN_MASK;
		cmdbuf[0] = PCF8583_REG_CSR;
		if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
	    	 cmdbuf, 1, &mode, 1, 0) != 0) {
			aprint_error_dev(self, "unable to write CSR\n");
			return;
		}
	}
 
	cmdbuf[0] = PCF8583_REG_CSR;
	if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
	    cmdbuf, 1, &csr, 1, 0) != 0) {
		aprint_error_dev(self, "unable to read CSR\n");
		return;
	}

	switch (csr & PCF8583_CSR_FN_MASK) {
	case PCF8583_CSR_FN_32768HZ:
		aprint_naive(": Mode 0: 32768 Hz TOD Clock");
		aprint_normal(": PCF8583 Mode 0: 32768 Hz TOD Clock");
		break;

	case PCF8583_CSR_FN_50HZ:
		aprint_naive(": Mode 1: 50Hz TOD Clock");
		aprint_normal(": PCF8583 Mode 1: 50Hz TOD Clock");
		break;

	case PCF8583_CSR_FN_EVENT:
		aprint_naive(": Mode 2: Counter");
		aprint_normal(": PCF8583 Mode 2: Counter");
		break;

	case PCF8583_CSR_FN_TEST:
		aprint_naive(": Mode 3: Test mode");
		aprint_normal(": PCF8583 Mode 3: Test mode");
		break;
	}
	aprint_normal("\n");

	sc->sc_open = 0;

	switch (csr & PCF8583_CSR_FN_MASK) {

	case PCF8583_CSR_FN_32768HZ:
	case PCF8583_CSR_FN_50HZ:
		sc->sc_todr.todr_dev = self;
		sc->sc_todr.todr_gettime = pcfrtc_gettime;
		sc->sc_todr.todr_settime = pcfrtc_settime;

		todr_attach(&sc->sc_todr);
		break;

	case PCF8583_CSR_FN_EVENT:
		if ((sc->sc_sme = sysmon_envsys_create()) == NULL) {
			aprint_error_dev(sc->sc_dev,
			  "unable to create sysmon structure");
			sc->sc_sme = NULL;
			return ;
		}
		sc->sc_counter.units=ENVSYS_INTEGER;
		sc->sc_counter.state=ENVSYS_SINVALID;
		strlcpy(sc->sc_counter.desc, "counter",
		 sizeof(sc->sc_counter.desc));
		if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_counter)) {
			sysmon_envsys_destroy(sc->sc_sme);
			return;
		}
		
		sc->sc_sme->sme_name = device_xname(self) ;
		sc->sc_sme->sme_refresh = pcfrtc_readcount;
		sc->sc_sme->sme_cookie = sc;

		if (sysmon_envsys_register(sc->sc_sme)) {
			sysmon_envsys_destroy(sc->sc_sme);
			return;
		}

		/* setup sysctl for resetting counter */

		if ((error = pcfrtc_sysctl_setup(sc)) !=0) {
			aprint_error_dev(sc->sc_dev, "cannot setup sysctl tree (%d)\n", error);
			sysmon_envsys_destroy(sc->sc_sme);
		}
		sc->reset_counter = 0;
		break ;
	}
}

/*ARGSUSED*/
int
pcfrtc_open(dev_t dev, int flag, int fmt, struct lwp *l)
{
	struct pcfrtc_softc *sc;

	if ((sc = device_lookup_private(&pcfrtc_cd, minor(dev))) == NULL)
		return (ENXIO);

	/* XXX: Locking */

	if (sc->sc_open)
		return (EBUSY);

	sc->sc_open = 1;
	return (0);
}

/*ARGSUSED*/
int
pcfrtc_close(dev_t dev, int flag, int fmt, struct lwp *l)
{
	struct pcfrtc_softc *sc;

	if ((sc = device_lookup_private(&pcfrtc_cd, minor(dev))) == NULL)
		return (ENXIO);

	sc->sc_open = 0;
	return (0);
}

/*ARGSUSED*/
int
pcfrtc_read(dev_t dev, struct uio *uio, int flags)
{
	struct pcfrtc_softc *sc;
	u_int8_t ch, cmdbuf[1];
	int a, error;

	if ((sc = device_lookup_private(&pcfrtc_cd, minor(dev))) == NULL)
		return (ENXIO);

	if (uio->uio_offset >= PCF8583_NVRAM_SIZE)
		return (EINVAL);

	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
		return (error);

	while (uio->uio_resid && uio->uio_offset < PCF8583_NVRAM_SIZE) {
		a = (int)uio->uio_offset;
		cmdbuf[0] = a + PCF8583_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,
			    "pcfrtc_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
pcfrtc_write(dev_t dev, struct uio *uio, int flags)
{
	struct pcfrtc_softc *sc;
	u_int8_t cmdbuf[2];
	int a, error;

	if ((sc = device_lookup_private(&pcfrtc_cd, minor(dev))) == NULL)
		return (ENXIO);

	if (uio->uio_offset >= PCF8583_NVRAM_SIZE)
		return (EINVAL);

	if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
		return (error);

	while (uio->uio_resid && uio->uio_offset < PCF8583_NVRAM_SIZE) {
		a = (int)uio->uio_offset;
		cmdbuf[0] = a + PCF8583_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,
			    "pcfrtc_write: write failed at 0x%x\n", a);
			return (error);
		}
	}

	iic_release_bus(sc->sc_tag, 0);

	return (error);
}

static int
pcfrtc_gettime(struct todr_chip_handle *ch, struct timeval *tv)
{
	struct pcfrtc_softc *sc = device_private(ch->todr_dev);
	struct clock_ymdhms dt;
	int err;
	uint8_t centi;

	if ((err = pcfrtc_clock_read(sc, &dt, &centi)))
		return err;

	tv->tv_sec = clock_ymdhms_to_secs(&dt);
	tv->tv_usec = centi * 10000;

	return (0);
}

static int
pcfrtc_settime(struct todr_chip_handle *ch, struct timeval *tv)
{
	struct pcfrtc_softc *sc = device_private(ch->todr_dev);
	struct clock_ymdhms dt;
	int err;

	clock_secs_to_ymdhms(tv->tv_sec, &dt);

	if ((err = pcfrtc_clock_write(sc, &dt, tv->tv_usec / 10000)) != 0)
		return err;

	return (0);
}

static const int pcf8583_rtc_offset[] = {
	PCF8583_REG_CSR,
	PCF8583_REG_CENTI,
	PCF8583_REG_SEC,
	PCF8583_REG_MIN,
	PCF8583_REG_HOUR,
	PCF8583_REG_YEARDATE,
	PCF8583_REG_WKDYMON,
	PCF8583_REG_TIMER,
	0xc0,			/* NVRAM -- year stored here */
	0xc1,			/* NVRAM -- century stored here */
};

static int
pcfrtc_clock_read(struct pcfrtc_softc *sc, struct clock_ymdhms *dt,
    uint8_t *centi)
{
	u_int8_t bcd[10], cmdbuf[1];
	int i, err;

	if ((err = iic_acquire_bus(sc->sc_tag, 0))) {
		aprint_error_dev(sc->sc_dev,
		    "pcfrtc_clock_read: failed to acquire I2C bus\n");
		return err;
	}

	/* Read each timekeeping register in order. */
	for (i = 0; i < 10; i++) {
		cmdbuf[0] = pcf8583_rtc_offset[i];

		if ((err = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
			     sc->sc_address, cmdbuf, 1,
			     &bcd[i], 1, 0))) {
			iic_release_bus(sc->sc_tag, 0);
			aprint_error_dev(sc->sc_dev,
			    "pcfrtc_clock_read: failed to read rtc "
			    "at 0x%x\n",
			    pcf8583_rtc_offset[i]);
			return err;
		}
	}

	/* Done with I2C */
	iic_release_bus(sc->sc_tag, 0);

	/*
	 * Convert the PCF8583's register values into something useable
	 */
	*centi      = bcdtobin(bcd[PCF8583_REG_CENTI]);
	dt->dt_sec  = bcdtobin(bcd[PCF8583_REG_SEC]);
	dt->dt_min  = bcdtobin(bcd[PCF8583_REG_MIN]);
	dt->dt_hour = bcdtobin(bcd[PCF8583_REG_HOUR] & PCF8583_HOUR_MASK);
	if (bcd[PCF8583_REG_HOUR] & PCF8583_HOUR_12H) {
		dt->dt_hour %= 12;	/* 12AM -> 0, 12PM -> 12 */
		if (bcd[PCF8583_REG_HOUR] & PCF8583_HOUR_PM)
			dt->dt_hour += 12;
	}

	dt->dt_day = bcdtobin(bcd[PCF8583_REG_YEARDATE] & PCF8583_DATE_MASK);
	dt->dt_mon = bcdtobin(bcd[PCF8583_REG_WKDYMON] & PCF8583_MON_MASK);

	dt->dt_year = bcd[8] + (bcd[9] * 100);
	/* Try to notice if the year's rolled over. */
	if (bcd[PCF8583_REG_CSR] & PCF8583_CSR_MASK)
		aprint_error_dev(sc->sc_dev,
		    "cannot check year in mask mode\n");
	else {
		while (dt->dt_year % 4 !=
		       (bcd[PCF8583_REG_YEARDATE] &
			PCF8583_YEAR_MASK) >> PCF8583_YEAR_SHIFT)
			dt->dt_year++;
	}

	return 0;
}

static int
pcfrtc_clock_write(struct pcfrtc_softc *sc, struct clock_ymdhms *dt,
    uint8_t centi)
{
	uint8_t bcd[10], cmdbuf[2];
	int i, err;

	/*
	 * Convert our time representation into something the PCF8583
	 * can understand.
	 */
	bcd[PCF8583_REG_CENTI]    = centi;
	bcd[PCF8583_REG_SEC]      = bintobcd(dt->dt_sec);
	bcd[PCF8583_REG_MIN]      = bintobcd(dt->dt_min);
	bcd[PCF8583_REG_HOUR]     = bintobcd(dt->dt_hour) & PCF8583_HOUR_MASK;
	bcd[PCF8583_REG_YEARDATE] = bintobcd(dt->dt_day) |
	    ((dt->dt_year % 4) << PCF8583_YEAR_SHIFT);
	bcd[PCF8583_REG_WKDYMON]  = bintobcd(dt->dt_mon) |
	    ((dt->dt_wday % 4) << PCF8583_WKDY_SHIFT);
	bcd[8]                    = dt->dt_year % 100;
	bcd[9]                    = dt->dt_year / 100;

	if ((err = iic_acquire_bus(sc->sc_tag, 0))) {
		aprint_error_dev(sc->sc_dev,
		    "pcfrtc_clock_write: failed to acquire I2C bus\n");
		return err;
	}

	for (i = 1; i < 10; i++) {
		cmdbuf[0] = pcf8583_rtc_offset[i];
		if ((err = iic_exec(sc->sc_tag,
			     i != 9 ? I2C_OP_WRITE : I2C_OP_WRITE_WITH_STOP,
			     sc->sc_address, cmdbuf, 1,
			     &bcd[i], 1, 0))) {
			iic_release_bus(sc->sc_tag, 0);
			aprint_error_dev(sc->sc_dev,
			    "pcfrtc_clock_write: failed to write rtc "
			    " at 0x%x\n",
			    pcf8583_rtc_offset[i]);
			return err;
		}
	}

	iic_release_bus(sc->sc_tag, 0);

	return 0;
}

int
pcfrtc_bootstrap_read(i2c_tag_t tag, int i2caddr, int offset,
    u_int8_t *rvp, size_t len)
{
	u_int8_t cmdbuf[1];

	/*
	 * NOTE: "offset" is an absolute offset into the PCF8583
	 * address space, not relative to the NVRAM.
	 */

	if (len == 0)
		return (0);

	if (iic_acquire_bus(tag, 0) != 0)
		return (-1);

	while (len) {
		/* Read a single byte. */
		cmdbuf[0] = offset;
		if (iic_exec(tag, I2C_OP_READ_WITH_STOP, i2caddr,
			     cmdbuf, 1, rvp, 1, 0)) {
			iic_release_bus(tag, 0);
			return (-1);
		}

		len--;
		rvp++;
		offset++;
	}

	iic_release_bus(tag, 0);
	return (0);
}

int
pcfrtc_bootstrap_write(i2c_tag_t tag, int i2caddr, int offset,
    u_int8_t *rvp, size_t len)
{
	u_int8_t cmdbuf[1];

	/*
	 * NOTE: "offset" is an absolute offset into the PCF8583
	 * address space, not relative to the NVRAM.
	 */

	if (len == 0)
		return (0);

	if (iic_acquire_bus(tag, 0) != 0)
		return (-1);

	while (len) {
		/* Write a single byte. */
		cmdbuf[0] = offset;
		if (iic_exec(tag, I2C_OP_WRITE_WITH_STOP, i2caddr,
			     cmdbuf, 1, rvp, 1, 0)) {
			iic_release_bus(tag, 0);
			return (-1);
		}

		len--;
		rvp++;
		offset++;
	}

	iic_release_bus(tag, 0);
	return (0);
}

int pcfrtc_sysctl_check(SYSCTLFN_ARGS)
{
	struct sysctlnode node;
	int t, error;

	t = *(int *)rnode->sysctl_data;

	node = *rnode;
	node.sysctl_data = &t;
	error = sysctl_lookup(SYSCTLFN_CALL(&node));
	if (error || newp == NULL)
		return (error);

	if (t < 0 || t > 1)
		return (EINVAL);

	*(int *)rnode->sysctl_data = t;
	return 0;
}

static int pcfrtc_sysctl_setup(struct pcfrtc_softc *sc)
{
	int error;
	const struct sysctlnode *cnode;
	int sysctlroot_num;

	if ((error = sysctl_createv(&sc->sc_pcfrtclog, 0, NULL, &cnode,
		0, CTLTYPE_NODE, device_xname(sc->sc_dev),
		SYSCTL_DESCR("pcfrtc counter reset"), NULL, 0, NULL, 0,
		CTL_HW, CTL_CREATE, CTL_EOL)) != 0)
		return error;
	sysctlroot_num = cnode->sysctl_num;

	if ((error = sysctl_createv(&sc->sc_pcfrtclog, 0, NULL, &cnode,
		CTLFLAG_READWRITE, CTLTYPE_INT, "counter_reset",
		SYSCTL_DESCR("counter reset"), pcfrtc_sysctl_check, 0,
		&sc->reset_counter, 0, CTL_HW,
		sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
		return error;
	return 0;
}

static void pcfrtc_readcount(struct sysmon_envsys *sme, envsys_data_t *edata)
{
	struct pcfrtc_softc *sc = sme->sme_cookie;
	int err, i;
	uint8_t bcd[3],cmdbuf[1];
	uint8_t zero=0;
 
	if ((err = iic_acquire_bus(sc->sc_tag, 0))) {
		aprint_error_dev(sc->sc_dev,
		    "pcfrtc_readcount: failed to acquire I2C bus\n");
		return;
	}

	for (i = PCF8583_COUNTER0; i <= PCF8583_COUNTER2; i++) {
                cmdbuf[0] = i;
                
                if ((err = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
                             sc->sc_address, cmdbuf, 1,
                             &bcd[i-1], 1, 0))) {
                        iic_release_bus(sc->sc_tag, 0);
                        aprint_error_dev(sc->sc_dev,
                            "pcfrtc_readcount: failed to read register at %x\n", i);
                        return;
                }
        }
 

	edata->value_cur = bcdtobin(bcd[0]) + bcdtobin(bcd[1])*100 + bcdtobin(bcd[2])*10000 ;
	edata->state = ENVSYS_SVALID ;
	
	/* if reset_counter = 1 then clear totals */

	if (sc->reset_counter != 0) {
		for (i = PCF8583_COUNTER0; i <= PCF8583_COUNTER2; i++) {
                	cmdbuf[0] = i;
                
                	if ((err = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
					sc->sc_address, cmdbuf, 1, &zero, 1, 0))) {
                        	iic_release_bus(sc->sc_tag, 0);
                        	aprint_error_dev(sc->sc_dev,
					"pcfrtc_readcount: failed to write register at %x\n", i);
				return;
                	}
        	}
 
		sc->reset_counter = 0 ;
	}

	iic_release_bus(sc->sc_tag, 0);
}
