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      1 /* $NetBSD: cwfg.c,v 1.6 2025/09/17 13:42:42 thorpej Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2020 Jared McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: cwfg.c,v 1.6 2025/09/17 13:42:42 thorpej Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/systm.h>
     34 #include <sys/kernel.h>
     35 #include <sys/device.h>
     36 #include <sys/conf.h>
     37 #include <sys/bus.h>
     38 #include <sys/kmem.h>
     39 
     40 #include <dev/i2c/i2cvar.h>
     41 
     42 #include <dev/sysmon/sysmonvar.h>
     43 #include <dev/sysmon/sysmon_taskq.h>
     44 
     45 #include <dev/fdt/fdtvar.h>
     46 
     47 #define	VERSION_REG	0x00
     48 #define	VCELL_HI_REG	0x02
     49 #define	 VCELL_HI	__BITS(5,0)
     50 #define	VCELL_LO_REG	0x03
     51 #define	 VCELL_LO	__BITS(7,0)
     52 #define	SOC_HI_REG	0x04
     53 #define	SOC_LO_REG	0x05
     54 #define	RTT_ALRT_HI_REG	0x06
     55 #define	 RTT_ALRT	__BIT(7)
     56 #define	 RTT_HI		__BITS(4,0)
     57 #define	RTT_ALRT_LO_REG	0x07
     58 #define	 RTT_LO		__BITS(7,0)
     59 #define	CONFIG_REG	0x08
     60 #define	 CONFIG_ATHD	__BITS(7,3)
     61 #define	 CONFIG_UFG	__BIT(1)
     62 #define	MODE_REG	0x0a
     63 #define	 MODE_SLEEP	__BITS(7,6)
     64 #define	  MODE_SLEEP_WAKE	0x0
     65 #define	  MODE_SLEEP_SLEEP	0x3
     66 #define	 MODE_QSTRT	__BITS(5,4)
     67 #define	 MODE_POR	__BITS(3,0)
     68 #define	BATINFO_REG(n)	(0x10 + (n))
     69 
     70 #define	VCELL_STEP	312
     71 #define	VCELL_DIV	1024
     72 #define	BATINFO_SIZE	64
     73 #define	RESET_COUNT	30
     74 #define	RESET_DELAY	100000
     75 
     76 enum cwfg_sensor {
     77 	CWFG_SENSOR_VCELL,
     78 	CWFG_SENSOR_SOC,
     79 	CWFG_SENSOR_RTT,
     80 	CWFG_NSENSORS
     81 };
     82 
     83 struct cwfg_softc {
     84 	device_t	sc_dev;
     85 	i2c_tag_t	sc_i2c;
     86 	i2c_addr_t	sc_addr;
     87 	int		sc_phandle;
     88 
     89 	uint8_t		sc_batinfo[BATINFO_SIZE];
     90 
     91 	u_int		sc_alert_level;
     92 	u_int		sc_monitor_interval;
     93 	u_int		sc_design_capacity;
     94 
     95 	struct sysmon_envsys *sc_sme;
     96 
     97 	envsys_data_t	sc_sensor[CWFG_NSENSORS];
     98 };
     99 
    100 #define	CWFG_MONITOR_INTERVAL_DEFAULT	8
    101 #define	CWFG_DESIGN_CAPACITY_DEFAULT	2000
    102 #define	CWFG_ALERT_LEVEL_DEFAULT	0
    103 
    104 static const struct device_compatible_entry compat_data[] = {
    105 	{ .compat = "cellwise,cw2015" },
    106 	{ .compat = "cellwise,cw201x" },	/* DTCOMPAT */
    107 	DEVICE_COMPAT_EOL
    108 };
    109 
    110 static int
    111 cwfg_lock(struct cwfg_softc *sc)
    112 {
    113 	return iic_acquire_bus(sc->sc_i2c, 0);
    114 }
    115 
    116 static void
    117 cwfg_unlock(struct cwfg_softc *sc)
    118 {
    119 	iic_release_bus(sc->sc_i2c, 0);
    120 }
    121 
    122 static int
    123 cwfg_read(struct cwfg_softc *sc, uint8_t reg, uint8_t *val)
    124 {
    125 	return iic_smbus_read_byte(sc->sc_i2c, sc->sc_addr, reg, val, 0);
    126 }
    127 
    128 static int
    129 cwfg_write(struct cwfg_softc *sc, uint8_t reg, uint8_t val)
    130 {
    131 	return iic_smbus_write_byte(sc->sc_i2c, sc->sc_addr, reg, val, 0);
    132 }
    133 
    134 static void
    135 cwfg_sensor_refresh(struct sysmon_envsys *sme, envsys_data_t *e)
    136 {
    137 	struct cwfg_softc *sc = sme->sme_cookie;
    138 	u_int vcell, rtt, tmp;
    139 	uint8_t val;
    140 	int error, n;
    141 
    142 	e->state = ENVSYS_SINVALID;
    143 
    144 	if ((error = cwfg_lock(sc)) != 0)
    145 		return;
    146 
    147 	switch (e->private) {
    148 	case CWFG_SENSOR_VCELL:
    149 		/* Take the average of three readings */
    150 		vcell = 0;
    151 		for (n = 0; n < 3; n++) {
    152 			if ((error = cwfg_read(sc, VCELL_HI_REG, &val)) != 0)
    153 				goto done;
    154 			tmp = __SHIFTOUT(val, VCELL_HI) << 8;
    155 			if ((error = cwfg_read(sc, VCELL_LO_REG, &val)) != 0)
    156 				goto done;
    157 			tmp |= __SHIFTOUT(val, VCELL_LO);
    158 			vcell += tmp;
    159 		}
    160 		vcell /= 3;
    161 
    162 		e->state = ENVSYS_SVALID;
    163 		e->value_cur = ((vcell * VCELL_STEP) / VCELL_DIV) * 1000;
    164 		break;
    165 
    166 	case CWFG_SENSOR_SOC:
    167 		if ((error = cwfg_read(sc, SOC_HI_REG, &val)) != 0)
    168 			goto done;
    169 
    170 		if (val != 0xff) {
    171 			e->state = ENVSYS_SVALID;
    172 			e->value_cur = val;			/* batt % */
    173 		}
    174 		break;
    175 
    176 	case CWFG_SENSOR_RTT:
    177 		if ((error = cwfg_read(sc, RTT_ALRT_HI_REG, &val)) != 0)
    178 			goto done;
    179 		rtt = __SHIFTOUT(val, RTT_HI) << 8;
    180 		if ((error = cwfg_read(sc, RTT_ALRT_LO_REG, &val)) != 0)
    181 			goto done;
    182 		rtt |= __SHIFTOUT(val, RTT_LO);
    183 
    184 		if (rtt != 0x1fff) {
    185 			e->state = ENVSYS_SVALID;
    186 			e->value_cur = rtt;			/* minutes */
    187 		}
    188 		break;
    189 	}
    190 
    191 done:
    192 	cwfg_unlock(sc);
    193 }
    194 
    195 static void
    196 cwfg_attach_battery(struct cwfg_softc *sc)
    197 {
    198 	envsys_data_t *e;
    199 
    200 	/* Cell voltage */
    201 	e = &sc->sc_sensor[CWFG_SENSOR_VCELL];
    202 	e->private = CWFG_SENSOR_VCELL;
    203 	e->units = ENVSYS_SVOLTS_DC;
    204 	e->state = ENVSYS_SINVALID;
    205 	strlcpy(e->desc, "battery voltage", sizeof(e->desc));
    206 	sysmon_envsys_sensor_attach(sc->sc_sme, e);
    207 
    208 	/* State of charge */
    209 	e = &sc->sc_sensor[CWFG_SENSOR_SOC];
    210 	e->private = CWFG_SENSOR_SOC;
    211 	e->units = ENVSYS_INTEGER;
    212 	e->state = ENVSYS_SINVALID;
    213 	e->flags = ENVSYS_FPERCENT;
    214 	strlcpy(e->desc, "battery percent", sizeof(e->desc));
    215 	sysmon_envsys_sensor_attach(sc->sc_sme, e);
    216 
    217 	/* Remaining run time */
    218 	e = &sc->sc_sensor[CWFG_SENSOR_RTT];
    219 	e->private = CWFG_SENSOR_RTT;
    220 	e->units = ENVSYS_INTEGER;
    221 	e->state = ENVSYS_SINVALID;
    222 	strlcpy(e->desc, "battery remaining minutes", sizeof(e->desc));
    223 	sysmon_envsys_sensor_attach(sc->sc_sme, e);
    224 }
    225 
    226 static void
    227 cwfg_attach_sensors(struct cwfg_softc *sc)
    228 {
    229 	sc->sc_sme = sysmon_envsys_create();
    230 	sc->sc_sme->sme_name = device_xname(sc->sc_dev);
    231 	sc->sc_sme->sme_cookie = sc;
    232 	sc->sc_sme->sme_refresh = cwfg_sensor_refresh;
    233 	sc->sc_sme->sme_events_timeout = sc->sc_monitor_interval;
    234 	sc->sc_sme->sme_class = SME_CLASS_BATTERY;
    235 	sc->sc_sme->sme_flags = SME_INIT_REFRESH;
    236 
    237 	cwfg_attach_battery(sc);
    238 
    239 	sysmon_envsys_register(sc->sc_sme);
    240 }
    241 
    242 static int
    243 cwfg_set_config(struct cwfg_softc *sc)
    244 {
    245 	u_int alert_level;
    246 	bool need_update;
    247 	uint8_t config, mode, val;
    248 	int error, n;
    249 
    250 	/* Read current config */
    251 	if ((error = cwfg_read(sc, CONFIG_REG, &config)) != 0)
    252 		return error;
    253 
    254 	/* Update alert level, if necessary */
    255 	alert_level = __SHIFTOUT(config, CONFIG_ATHD);
    256 	if (alert_level != sc->sc_alert_level) {
    257 		config &= ~CONFIG_ATHD;
    258 		config |= __SHIFTIN(sc->sc_alert_level, CONFIG_ATHD);
    259 		if ((error = cwfg_write(sc, CONFIG_REG, config)) != 0)
    260 			return error;
    261 	}
    262 
    263 	/* Re-read current config */
    264 	if ((error = cwfg_read(sc, CONFIG_REG, &config)) != 0)
    265 		return error;
    266 
    267 	/*
    268 	 * We need to upload a battery profile if either the UFG flag
    269 	 * is unset, or the current battery profile differs from the
    270 	 * one in the DT.
    271 	 */
    272 	need_update = (config & CONFIG_UFG) == 0;
    273 	if (need_update == false) {
    274 		for (n = 0; n < BATINFO_SIZE; n++) {
    275 			if ((error = cwfg_read(sc, BATINFO_REG(n), &val)) != 0)
    276 				return error;
    277 			if (sc->sc_batinfo[n] != val) {
    278 				need_update = true;
    279 				break;
    280 			}
    281 		}
    282 	}
    283 	if (need_update == false)
    284 		return 0;
    285 
    286 	aprint_verbose_dev(sc->sc_dev, "updating battery profile\n");
    287 
    288 	/* Update battery profile */
    289 	for (n = 0; n < BATINFO_SIZE; n++) {
    290 		val = sc->sc_batinfo[n];
    291 		if ((error = cwfg_write(sc, BATINFO_REG(n), val)) != 0)
    292 			return error;
    293 	}
    294 
    295 	/* Set UFG flag to switch to new profile */
    296 	if ((error = cwfg_read(sc, CONFIG_REG, &config)) != 0)
    297 		return error;
    298 	config |= CONFIG_UFG;
    299 	if ((error = cwfg_write(sc, CONFIG_REG, config)) != 0)
    300 		return error;
    301 
    302 	/* Restart the IC with new profile */
    303 	if ((error = cwfg_read(sc, MODE_REG, &mode)) != 0)
    304 		return error;
    305 	mode |= MODE_POR;
    306 	if ((error = cwfg_write(sc, MODE_REG, mode)) != 0)
    307 		return error;
    308 	delay(20000);
    309 	mode &= ~MODE_POR;
    310 	if ((error = cwfg_write(sc, MODE_REG, mode)) != 0)
    311 		return error;
    312 
    313 	return error;
    314 }
    315 
    316 static int
    317 cwfg_init(struct cwfg_softc *sc)
    318 {
    319 	uint8_t mode, soc;
    320 	int error, retry;
    321 
    322 	cwfg_lock(sc);
    323 
    324 	/* If the device is in sleep mode, wake it up */
    325 	if ((error = cwfg_read(sc, MODE_REG, &mode)) != 0)
    326 		goto done;
    327 	if (__SHIFTOUT(mode, MODE_SLEEP) == MODE_SLEEP_SLEEP) {
    328 		mode &= ~MODE_SLEEP;
    329 		mode |= __SHIFTIN(MODE_SLEEP_WAKE, MODE_SLEEP);
    330 		if ((error = cwfg_write(sc, MODE_REG, mode)) != 0)
    331 			goto done;
    332 	}
    333 
    334 	/* Load battery profile */
    335 	if ((error = cwfg_set_config(sc)) != 0)
    336 		goto done;
    337 
    338 	/* Wait for chip to become ready */
    339 	for (retry = RESET_COUNT; retry > 0; retry--) {
    340 		if ((error = cwfg_read(sc, SOC_HI_REG, &soc)) != 0)
    341 			goto done;
    342 		if (soc != 0xff)
    343 			break;
    344 		delay(RESET_DELAY);
    345 	}
    346 	if (retry == 0) {
    347 		aprint_error_dev(sc->sc_dev,
    348 		    "WARNING: timeout waiting for chip ready\n");
    349 	}
    350 
    351 done:
    352 	cwfg_unlock(sc);
    353 
    354 	return error;
    355 }
    356 
    357 static int
    358 cwfg_parse_resources(struct cwfg_softc *sc)
    359 {
    360 	const u_int *batinfo;
    361 	u_int val;
    362 	int len = 0, n;
    363 
    364 	batinfo = fdtbus_get_prop(sc->sc_phandle,
    365 	    "cellwise,battery-profile", &len);
    366 	if (batinfo == NULL) {
    367 		/* DTCOMPAT */
    368 		batinfo = fdtbus_get_prop(sc->sc_phandle,
    369 		    "cellwise,bat-config-info", &len);
    370 	}
    371 	switch (len) {
    372 	case BATINFO_SIZE:
    373 		memcpy(sc->sc_batinfo, batinfo, BATINFO_SIZE);
    374 		break;
    375 	case BATINFO_SIZE * 4:
    376 		for (n = 0; n < BATINFO_SIZE; n++)
    377 			sc->sc_batinfo[n] = be32toh(batinfo[n]);
    378 		break;
    379 	default:
    380 		aprint_error_dev(sc->sc_dev,
    381 		    "missing or invalid battery info\n");
    382 		return EINVAL;
    383 	}
    384 
    385 	if (of_getprop_uint32(sc->sc_phandle,
    386 	    "cellwise,monitor-interval-ms", &val) == 0) {
    387 		sc->sc_monitor_interval = howmany(val, 1000);
    388 	} else if (of_getprop_uint32(sc->sc_phandle,
    389 	    "cellwise,monitor-interval", &val) == 0) {
    390 		/* DTCOMPAT */
    391 		sc->sc_monitor_interval = val;
    392 	} else {
    393 		sc->sc_monitor_interval = CWFG_MONITOR_INTERVAL_DEFAULT;
    394 	}
    395 
    396 	const int bphandle = fdtbus_get_phandle(sc->sc_phandle, "monitored-battery");
    397 	if (bphandle != -1 && of_getprop_uint32(bphandle,
    398 	    "charge-full-design-microamp-hours", &val) == 0) {
    399 		sc->sc_design_capacity = howmany(val, 1000);
    400 	} else if (of_getprop_uint32(sc->sc_phandle,
    401 	    "cellwise,design-capacity", &val) == 0) {
    402 		/* DTCOMPAT */
    403 		sc->sc_design_capacity = val;
    404 	} else {
    405 		sc->sc_design_capacity = CWFG_DESIGN_CAPACITY_DEFAULT;
    406 	}
    407 
    408 	if (of_getprop_uint32(sc->sc_phandle,
    409 	    "cellwise,alert-level", &sc->sc_alert_level) != 0) {
    410 		sc->sc_alert_level = CWFG_ALERT_LEVEL_DEFAULT;
    411 	}
    412 
    413 	return 0;
    414 }
    415 
    416 static int
    417 cwfg_match(device_t parent, cfdata_t match, void *aux)
    418 {
    419 	struct i2c_attach_args *ia = aux;
    420 	int match_result;
    421 
    422 	if (iic_use_direct_match(ia, match, compat_data, &match_result))
    423 		return match_result;
    424 
    425 	/* This device is direct-config only. */
    426 
    427 	return 0;
    428 }
    429 
    430 static void
    431 cwfg_attach(device_t parent, device_t self, void *aux)
    432 {
    433 	struct cwfg_softc *sc = device_private(self);
    434 	struct i2c_attach_args *ia = aux;
    435 	uint8_t ver;
    436 	int error;
    437 
    438 	sc->sc_dev = self;
    439 	sc->sc_i2c = ia->ia_tag;
    440 	sc->sc_addr = ia->ia_addr;
    441 	sc->sc_phandle = devhandle_to_of(device_handle(self));
    442 
    443 	cwfg_lock(sc);
    444 	error = cwfg_read(sc, VERSION_REG, &ver);
    445 	cwfg_unlock(sc);
    446 
    447 	if (error != 0) {
    448 		aprint_error(": device not responding, error = %d\n", error);
    449 		return;
    450 	}
    451 
    452 	aprint_naive("\n");
    453 	aprint_normal(": CellWise CW2015 Fuel Gauge IC (ver. 0x%02x)\n", ver);
    454 
    455 	if (cwfg_parse_resources(sc) != 0) {
    456 		aprint_error_dev(self, "failed to parse resources\n");
    457 		return;
    458 	}
    459 
    460 	if (cwfg_init(sc) != 0) {
    461 		aprint_error_dev(self, "failed to initialize device\n");
    462 		return;
    463 	}
    464 
    465 	cwfg_attach_sensors(sc);
    466 }
    467 
    468 CFATTACH_DECL_NEW(cwfg, sizeof(struct cwfg_softc),
    469     cwfg_match, cwfg_attach, NULL, NULL);
    470