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piixpm.c revision 1.71
      1 /* $NetBSD: piixpm.c,v 1.71 2023/01/10 00:05:53 msaitoh Exp $ */
      2 /*	$OpenBSD: piixpm.c,v 1.39 2013/10/01 20:06:02 sf Exp $	*/
      3 
      4 /*
      5  * Copyright (c) 2005, 2006 Alexander Yurchenko <grange (at) openbsd.org>
      6  *
      7  * Permission to use, copy, modify, and distribute this software for any
      8  * purpose with or without fee is hereby granted, provided that the above
      9  * copyright notice and this permission notice appear in all copies.
     10  *
     11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
     12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     18  */
     19 
     20 /*
     21  * Intel PIIX and compatible Power Management controller driver.
     22  */
     23 
     24 #include <sys/cdefs.h>
     25 __KERNEL_RCSID(0, "$NetBSD: piixpm.c,v 1.71 2023/01/10 00:05:53 msaitoh Exp $");
     26 
     27 #include <sys/param.h>
     28 #include <sys/systm.h>
     29 #include <sys/device.h>
     30 #include <sys/kernel.h>
     31 #include <sys/mutex.h>
     32 #include <sys/condvar.h>
     33 #include <sys/proc.h>
     34 
     35 #include <sys/bus.h>
     36 
     37 #include <dev/pci/pcidevs.h>
     38 #include <dev/pci/pcireg.h>
     39 #include <dev/pci/pcivar.h>
     40 
     41 #include <dev/pci/piixpmreg.h>
     42 
     43 #include <dev/i2c/i2cvar.h>
     44 
     45 #include <dev/ic/acpipmtimer.h>
     46 
     47 #ifdef PIIXPM_DEBUG
     48 #define DPRINTF(x) printf x
     49 #else
     50 #define DPRINTF(x)
     51 #endif
     52 
     53 #define PIIXPM_IS_CSB5(sc)						      \
     54 	(PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_SERVERWORKS &&		      \
     55 	    PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_SERVERWORKS_CSB5)
     56 #define PIIXPM_DELAY	200
     57 #define PIIXPM_TIMEOUT	1
     58 
     59 #define PIIXPM_IS_SB800GRP(sc)						      \
     60 	((PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_ATI) &&			      \
     61 	    ((PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_ATI_SB600_SMB) &&	      \
     62 		((sc)->sc_rev >= 0x40)))
     63 
     64 #define PIIXPM_IS_HUDSON(sc)						      \
     65 	((PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_AMD) &&			      \
     66 	    (PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_AMD_HUDSON_SMB))
     67 
     68 #define PIIXPM_IS_KERNCZ(sc)						      \
     69 	((PCI_VENDOR((sc)->sc_id) == PCI_VENDOR_AMD) &&			      \
     70 	    (PCI_PRODUCT((sc)->sc_id) == PCI_PRODUCT_AMD_KERNCZ_SMB))
     71 
     72 #define PIIXPM_IS_FCHGRP(sc)	(PIIXPM_IS_HUDSON(sc) || PIIXPM_IS_KERNCZ(sc))
     73 
     74 #define PIIX_SB800_TIMEOUT 500
     75 
     76 struct piixpm_smbus {
     77 	int			sda;
     78 	int			sda_save;
     79 	struct piixpm_softc	*softc;
     80 };
     81 
     82 struct piixpm_softc {
     83 	device_t		sc_dev;
     84 
     85 	bus_space_tag_t		sc_iot;
     86 	bus_space_tag_t		sc_sb800_bt;
     87 	bus_space_handle_t	sc_pm_ioh;
     88 	bus_space_handle_t	sc_sb800_bh;
     89 	bus_space_handle_t	sc_smb_ioh;
     90 	void *			sc_smb_ih;
     91 	int			sc_poll;
     92 	bool			sc_sb800_mmio;	/* Use MMIO access */
     93 	bool			sc_sb800_selen; /* Use SMBUS0SEL */
     94 
     95 	pci_chipset_tag_t	sc_pc;
     96 	pcitag_t		sc_pcitag;
     97 	pcireg_t		sc_id;
     98 	pcireg_t		sc_rev;
     99 
    100 	int			sc_numbusses;
    101 	device_t		sc_i2c_device[4];
    102 	struct piixpm_smbus	sc_busses[4];
    103 	struct i2c_controller	sc_i2c_tags[4];
    104 
    105 	kmutex_t		sc_exec_lock;
    106 	kcondvar_t		sc_exec_wait;
    107 
    108 	struct {
    109 		i2c_op_t	op;
    110 		void *		buf;
    111 		size_t		len;
    112 		int		flags;
    113 		int             error;
    114 		bool            done;
    115 	}			sc_i2c_xfer;
    116 
    117 	pcireg_t		sc_devact[2];
    118 };
    119 
    120 static int	piixpm_match(device_t, cfdata_t, void *);
    121 static void	piixpm_attach(device_t, device_t, void *);
    122 static int	piixpm_rescan(device_t, const char *, const int *);
    123 static void	piixpm_chdet(device_t, device_t);
    124 
    125 static bool	piixpm_suspend(device_t, const pmf_qual_t *);
    126 static bool	piixpm_resume(device_t, const pmf_qual_t *);
    127 
    128 static uint8_t	piixpm_sb800_pmread(struct piixpm_softc *, bus_size_t);
    129 static int	piixpm_sb800_init(struct piixpm_softc *);
    130 static void	piixpm_csb5_reset(void *);
    131 static int	piixpm_i2c_sb800_acquire_bus(void *, int);
    132 static void	piixpm_i2c_sb800_release_bus(void *, int);
    133 static int	piixpm_i2c_exec(void *, i2c_op_t, i2c_addr_t, const void *,
    134     size_t, void *, size_t, int);
    135 
    136 static int	piixpm_intr(void *);
    137 
    138 CFATTACH_DECL3_NEW(piixpm, sizeof(struct piixpm_softc),
    139     piixpm_match, piixpm_attach, NULL, NULL, piixpm_rescan, piixpm_chdet, 0);
    140 
    141 static int
    142 piixpm_match(device_t parent, cfdata_t match, void *aux)
    143 {
    144 	struct pci_attach_args *pa;
    145 
    146 	pa = (struct pci_attach_args *)aux;
    147 	switch (PCI_VENDOR(pa->pa_id)) {
    148 	case PCI_VENDOR_INTEL:
    149 		switch (PCI_PRODUCT(pa->pa_id)) {
    150 		case PCI_PRODUCT_INTEL_82371AB_PMC:
    151 		case PCI_PRODUCT_INTEL_82440MX_PMC:
    152 			return 1;
    153 		}
    154 		break;
    155 	case PCI_VENDOR_ATI:
    156 		switch (PCI_PRODUCT(pa->pa_id)) {
    157 		case PCI_PRODUCT_ATI_SB200_SMB:
    158 		case PCI_PRODUCT_ATI_SB300_SMB:
    159 		case PCI_PRODUCT_ATI_SB400_SMB:
    160 		case PCI_PRODUCT_ATI_SB600_SMB:	/* matches SB600/SB700/SB800 */
    161 			return 1;
    162 		}
    163 		break;
    164 	case PCI_VENDOR_SERVERWORKS:
    165 		switch (PCI_PRODUCT(pa->pa_id)) {
    166 		case PCI_PRODUCT_SERVERWORKS_OSB4:
    167 		case PCI_PRODUCT_SERVERWORKS_CSB5:
    168 		case PCI_PRODUCT_SERVERWORKS_CSB6:
    169 		case PCI_PRODUCT_SERVERWORKS_HT1000SB:
    170 		case PCI_PRODUCT_SERVERWORKS_HT1100SB:
    171 			return 1;
    172 		}
    173 		break;
    174 	case PCI_VENDOR_AMD:
    175 		switch (PCI_PRODUCT(pa->pa_id)) {
    176 		case PCI_PRODUCT_AMD_HUDSON_SMB:
    177 		case PCI_PRODUCT_AMD_KERNCZ_SMB:
    178 			return 1;
    179 		}
    180 		break;
    181 	}
    182 
    183 	return 0;
    184 }
    185 
    186 static void
    187 piixpm_attach(device_t parent, device_t self, void *aux)
    188 {
    189 	struct piixpm_softc *sc = device_private(self);
    190 	struct pci_attach_args *pa = aux;
    191 	pcireg_t base, conf;
    192 	pcireg_t pmmisc;
    193 	pci_intr_handle_t ih;
    194 	bool usesmi = false;
    195 	const char *intrstr = NULL;
    196 	int i;
    197 	char intrbuf[PCI_INTRSTR_LEN];
    198 
    199 	sc->sc_dev = self;
    200 	sc->sc_iot = pa->pa_iot;
    201 	sc->sc_id = pa->pa_id;
    202 	sc->sc_rev = PCI_REVISION(pa->pa_class);
    203 	sc->sc_pc = pa->pa_pc;
    204 	sc->sc_pcitag = pa->pa_tag;
    205 	sc->sc_numbusses = 1;
    206 
    207 	pci_aprint_devinfo(pa, NULL);
    208 
    209 	mutex_init(&sc->sc_exec_lock, MUTEX_DEFAULT, IPL_BIO);
    210 	cv_init(&sc->sc_exec_wait, device_xname(self));
    211 
    212 	if (!pmf_device_register(self, piixpm_suspend, piixpm_resume))
    213 		aprint_error_dev(self, "couldn't establish power handler\n");
    214 
    215 	if ((PCI_VENDOR(pa->pa_id) != PCI_VENDOR_INTEL) ||
    216 	    (PCI_PRODUCT(pa->pa_id) != PCI_PRODUCT_INTEL_82371AB_PMC))
    217 		goto nopowermanagement;
    218 
    219 	/* check whether I/O access to PM regs is enabled */
    220 	pmmisc = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PMREGMISC);
    221 	if (!(pmmisc & 1))
    222 		goto nopowermanagement;
    223 
    224 	/* Map I/O space */
    225 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_PM_BASE);
    226 	if (base == 0 || bus_space_map(sc->sc_iot, PCI_MAPREG_IO_ADDR(base),
    227 	    PIIX_PM_SIZE, 0, &sc->sc_pm_ioh)) {
    228 		aprint_error_dev(self,
    229 		    "can't map power management I/O space\n");
    230 		goto nopowermanagement;
    231 	}
    232 
    233 	/*
    234 	 * Revision 0 and 1 are PIIX4, 2 is PIIX4E, 3 is PIIX4M.
    235 	 * PIIX4 and PIIX4E have a bug in the timer latch, see Errata #20
    236 	 * in the "Specification update" (document #297738).
    237 	 */
    238 	acpipmtimer_attach(self, sc->sc_iot, sc->sc_pm_ioh, PIIX_PM_PMTMR,
    239 	    (PCI_REVISION(pa->pa_class) < 3) ? ACPIPMT_BADLATCH : 0);
    240 
    241 nopowermanagement:
    242 
    243 	/* SB800 rev 0x40+, AMD HUDSON and newer need special initialization */
    244 	if (PIIXPM_IS_FCHGRP(sc) || PIIXPM_IS_SB800GRP(sc)) {
    245 		/* Newer chips don't support I/O access */
    246 		if (PIIXPM_IS_KERNCZ(sc) && (sc->sc_rev >= 0x51)) {
    247 			sc->sc_sb800_mmio = true;
    248 			sc->sc_sb800_bt = pa->pa_memt;
    249 		} else {
    250 			sc->sc_sb800_mmio = false;
    251 			sc->sc_sb800_bt = pa->pa_iot;
    252 		}
    253 
    254 		if (piixpm_sb800_init(sc) == 0) {
    255 			/* Read configuration */
    256 			conf = bus_space_read_1(sc->sc_iot,
    257 			    sc->sc_smb_ioh, SB800_SMB_HOSTC);
    258 			usesmi = ((conf & SB800_SMB_HOSTC_IRQ) == 0);
    259 			goto setintr;
    260 		}
    261 		aprint_normal_dev(self, "SMBus initialization failed\n");
    262 		return;
    263 	}
    264 
    265 	/* Read configuration */
    266 	conf = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_HOSTC);
    267 	DPRINTF(("%s: conf 0x%08x\n", device_xname(self), conf));
    268 
    269 	if ((conf & PIIX_SMB_HOSTC_HSTEN) == 0) {
    270 		aprint_normal_dev(self, "SMBus disabled\n");
    271 		return;
    272 	}
    273 	usesmi = (conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_SMI;
    274 
    275 	/* Map I/O space */
    276 	base = pci_conf_read(pa->pa_pc, pa->pa_tag, PIIX_SMB_BASE) & 0xffff;
    277 	if (base == 0 ||
    278 	    bus_space_map(sc->sc_iot, PCI_MAPREG_IO_ADDR(base),
    279 	    PIIX_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
    280 		aprint_error_dev(self, "can't map smbus I/O space\n");
    281 		return;
    282 	}
    283 
    284 setintr:
    285 	sc->sc_poll = 1;
    286 	aprint_normal_dev(self, "");
    287 	if (usesmi) {
    288 		/* No PCI IRQ */
    289 		aprint_normal("interrupting at SMI, ");
    290 	} else {
    291 		if ((conf & PIIX_SMB_HOSTC_INTMASK) == PIIX_SMB_HOSTC_IRQ) {
    292 			/* Install interrupt handler */
    293 			if (pci_intr_map(pa, &ih) == 0) {
    294 				intrstr = pci_intr_string(pa->pa_pc, ih,
    295 				    intrbuf, sizeof(intrbuf));
    296 				pci_intr_setattr(pa->pa_pc, &ih,
    297 				    PCI_INTR_MPSAFE, true);
    298 				sc->sc_smb_ih = pci_intr_establish_xname(
    299 					pa->pa_pc, ih, IPL_BIO, piixpm_intr,
    300 					sc, device_xname(sc->sc_dev));
    301 				if (sc->sc_smb_ih != NULL) {
    302 					aprint_normal("interrupting at %s",
    303 					    intrstr);
    304 					sc->sc_poll = 0;
    305 				}
    306 			}
    307 		}
    308 		if (sc->sc_poll)
    309 			aprint_normal("polling");
    310 	}
    311 
    312 	aprint_normal("\n");
    313 
    314 	for (i = 0; i < sc->sc_numbusses; i++)
    315 		sc->sc_i2c_device[i] = NULL;
    316 
    317 	piixpm_rescan(self, NULL, NULL);
    318 }
    319 
    320 static int
    321 piixpm_iicbus_print(void *aux, const char *pnp)
    322 {
    323 	struct i2cbus_attach_args *iba = aux;
    324 	struct i2c_controller *tag = iba->iba_tag;
    325 	struct piixpm_smbus *bus = tag->ic_cookie;
    326 	struct piixpm_softc *sc = bus->softc;
    327 
    328 	iicbus_print(aux, pnp);
    329 	if (sc->sc_numbusses != 0)
    330 		aprint_normal(" port %d", bus->sda);
    331 
    332 	return UNCONF;
    333 }
    334 
    335 static int
    336 piixpm_rescan(device_t self, const char *ifattr, const int *locators)
    337 {
    338 	struct piixpm_softc *sc = device_private(self);
    339 	struct i2cbus_attach_args iba;
    340 	int i;
    341 
    342 	/* Attach I2C bus */
    343 
    344 	for (i = 0; i < sc->sc_numbusses; i++) {
    345 		struct i2c_controller *tag = &sc->sc_i2c_tags[i];
    346 
    347 		if (sc->sc_i2c_device[i] != NULL)
    348 			continue;
    349 		sc->sc_busses[i].sda = i;
    350 		sc->sc_busses[i].softc = sc;
    351 		iic_tag_init(tag);
    352 		tag->ic_cookie = &sc->sc_busses[i];
    353 		if (PIIXPM_IS_SB800GRP(sc) || PIIXPM_IS_FCHGRP(sc)) {
    354 			tag->ic_acquire_bus = piixpm_i2c_sb800_acquire_bus;
    355 			tag->ic_release_bus = piixpm_i2c_sb800_release_bus;
    356 		} else {
    357 			tag->ic_acquire_bus = NULL;
    358 			tag->ic_release_bus = NULL;
    359 		}
    360 		tag->ic_exec = piixpm_i2c_exec;
    361 		memset(&iba, 0, sizeof(iba));
    362 		iba.iba_tag = tag;
    363 		sc->sc_i2c_device[i] =
    364 		    config_found(self, &iba, piixpm_iicbus_print, CFARGS_NONE);
    365 		if (sc->sc_i2c_device[i] == NULL)
    366 			iic_tag_fini(tag);
    367 	}
    368 
    369 	return 0;
    370 }
    371 
    372 static void
    373 piixpm_chdet(device_t self, device_t child)
    374 {
    375 	struct piixpm_softc *sc = device_private(self);
    376 	int i;
    377 
    378 	for (i = 0; i < sc->sc_numbusses; i++) {
    379 		if (sc->sc_i2c_device[i] == child) {
    380 
    381 			struct i2c_controller *tag = &sc->sc_i2c_tags[i];
    382 
    383 			iic_tag_fini(tag);
    384 			sc->sc_i2c_device[i] = NULL;
    385 			break;
    386 		}
    387 	}
    388 }
    389 
    390 
    391 static bool
    392 piixpm_suspend(device_t dv, const pmf_qual_t *qual)
    393 {
    394 	struct piixpm_softc *sc = device_private(dv);
    395 
    396 	sc->sc_devact[0] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
    397 	    PIIX_DEVACTA);
    398 	sc->sc_devact[1] = pci_conf_read(sc->sc_pc, sc->sc_pcitag,
    399 	    PIIX_DEVACTB);
    400 
    401 	return true;
    402 }
    403 
    404 static bool
    405 piixpm_resume(device_t dv, const pmf_qual_t *qual)
    406 {
    407 	struct piixpm_softc *sc = device_private(dv);
    408 
    409 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTA,
    410 	    sc->sc_devact[0]);
    411 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_DEVACTB,
    412 	    sc->sc_devact[1]);
    413 
    414 	return true;
    415 }
    416 
    417 static uint8_t
    418 piixpm_sb800_pmread(struct piixpm_softc *sc, bus_size_t offset)
    419 {
    420 	bus_space_tag_t sbt = sc->sc_sb800_bt;
    421 	bus_space_handle_t sbh = sc->sc_sb800_bh;
    422 	uint8_t val;
    423 
    424 	if (sc->sc_sb800_mmio)
    425 		val = bus_space_read_1(sbt, sbh, offset);
    426 	else {
    427 		bus_space_write_1(sbt, sbh, SB800_INDIRECTIO_INDEX, offset);
    428 		val = bus_space_read_1(sbt, sbh, SB800_INDIRECTIO_DATA);
    429 	}
    430 
    431 	return val;
    432 }
    433 
    434 /*
    435  * Extract SMBus base address from SB800 Power Management (PM) registers.
    436  * The PM registers can be accessed either through indirect I/O (CD6/CD7) or
    437  * direct mapping if AcpiMMioDecodeEn is enabled. Newer devices support MMIO
    438  * access only.
    439  */
    440 static int
    441 piixpm_sb800_init(struct piixpm_softc *sc)
    442 {
    443 	bus_space_tag_t sbt = sc->sc_sb800_bt;
    444 	bus_space_handle_t sbh;	/* indirect memory or I/O handle */
    445 	int rv;
    446 	uint16_t base_addr;
    447 	uint8_t lo, hi;
    448 	bool enabled;
    449 
    450 	if (PIIXPM_IS_KERNCZ(sc) ||
    451 	    (PIIXPM_IS_HUDSON(sc) && (sc->sc_rev >= 0x1f)))
    452 		sc->sc_numbusses = 2;
    453 	else
    454 		sc->sc_numbusses = 4;
    455 
    456 	/* Check SMBus enable bit and Fetch SMB base address */
    457 	if (sc->sc_sb800_mmio)
    458 		rv = bus_space_map(sbt, SB800_FCH_PM_BASE,
    459 		    SB800_FCH_PM_SIZE, 0, &sbh);
    460 	else
    461 		rv = bus_space_map(sbt, SB800_INDIRECTIO_BASE,
    462 		    SB800_INDIRECTIO_SIZE, 0, &sbh);
    463 	if (rv != 0) {
    464 		device_printf(sc->sc_dev, "couldn't map indirect I/O space\n");
    465 		return EBUSY;
    466 	}
    467 	sc->sc_sb800_bh = sbh;
    468 	if (PIIXPM_IS_FCHGRP(sc)) {
    469 		lo = piixpm_sb800_pmread(sc, AMDFCH41_PM_DECODE_EN0);
    470 		enabled = lo & AMDFCH41_SMBUS_EN;
    471 		if (!enabled)
    472 			return ENOENT;
    473 
    474 		hi = piixpm_sb800_pmread(sc, AMDFCH41_PM_DECODE_EN1);
    475 		base_addr = (uint16_t)hi << 8;
    476 	} else {
    477 		uint8_t data;
    478 
    479 		lo = piixpm_sb800_pmread(sc, SB800_PM_SMBUS0EN_LO);
    480 		enabled = lo & SB800_PM_SMBUS0EN_ENABLE;
    481 		if (!enabled)
    482 			return ENOENT;
    483 
    484 		hi = piixpm_sb800_pmread(sc, SB800_PM_SMBUS0EN_HI);
    485 		base_addr = ((uint16_t)hi << 8) & SB800_PM_SMBUS0EN_BADDR;
    486 
    487 		bus_space_write_1(sbt, sbh, SB800_INDIRECTIO_INDEX,
    488 		    SB800_PM_SMBUS0SELEN);
    489 		data = bus_space_read_1(sbt, sbh, SB800_INDIRECTIO_DATA);
    490 		if ((data & SB800_PM_USE_SMBUS0SEL) != 0)
    491 			sc->sc_sb800_selen = true;
    492 	}
    493 
    494 	aprint_debug_dev(sc->sc_dev, "SMBus %s access @ 0x%04x\n",
    495 	    sc->sc_sb800_mmio ? "memory" : "I/O", base_addr);
    496 
    497 	if (bus_space_map(sc->sc_iot, PCI_MAPREG_IO_ADDR(base_addr),
    498 	    SB800_SMB_SIZE, 0, &sc->sc_smb_ioh)) {
    499 		aprint_error_dev(sc->sc_dev, "can't map smbus I/O space\n");
    500 		return EBUSY;
    501 	}
    502 
    503 	return 0;
    504 }
    505 
    506 static void
    507 piixpm_csb5_reset(void *arg)
    508 {
    509 	struct piixpm_softc *sc = arg;
    510 	pcireg_t base, hostc, pmbase;
    511 
    512 	base = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE);
    513 	hostc = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC);
    514 
    515 	pmbase = pci_conf_read(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE);
    516 	pmbase |= PIIX_PM_BASE_CSB5_RESET;
    517 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
    518 	pmbase &= ~PIIX_PM_BASE_CSB5_RESET;
    519 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_PM_BASE, pmbase);
    520 
    521 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_BASE, base);
    522 	pci_conf_write(sc->sc_pc, sc->sc_pcitag, PIIX_SMB_HOSTC, hostc);
    523 
    524 	(void) tsleep(&sc, PRIBIO, "csb5reset", hz/2);
    525 }
    526 
    527 static int
    528 piixpm_i2c_sb800_acquire_bus(void *cookie, int flags)
    529 {
    530 	struct piixpm_smbus *smbus = cookie;
    531 	struct piixpm_softc *sc = smbus->softc;
    532 	uint8_t sctl, old_sda, index, mask, reg;
    533 	int i;
    534 
    535 	sctl = bus_space_read_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_SC);
    536 	for (i = 0; i < PIIX_SB800_TIMEOUT; i++) {
    537 		/* Try to acquire the host semaphore */
    538 		sctl &= ~PIIX_SMB_SC_SEMMASK;
    539 		bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_SC,
    540 		    sctl | PIIX_SMB_SC_HOSTSEM);
    541 
    542 		sctl = bus_space_read_1(sc->sc_iot, sc->sc_smb_ioh,
    543 		    PIIX_SMB_SC);
    544 		if ((sctl & PIIX_SMB_SC_HOSTSEM) != 0)
    545 			break;
    546 
    547 		delay(1000);
    548 	}
    549 	if (i >= PIIX_SB800_TIMEOUT) {
    550 		device_printf(sc->sc_dev,
    551 		    "Failed to acquire the host semaphore\n");
    552 		return -1;
    553 	}
    554 
    555 	if (PIIXPM_IS_KERNCZ(sc) ||
    556 	    (PIIXPM_IS_HUDSON(sc) && (sc->sc_rev >= 0x1f))) {
    557 		index = AMDFCH41_PM_PORT_INDEX;
    558 		mask = AMDFCH41_SMBUS_PORTMASK;
    559 	} else if (sc->sc_sb800_selen) {
    560 		index = SB800_PM_SMBUS0SEL;
    561 		mask = SB800_PM_SMBUS0_MASK_E;
    562 	} else {
    563 		index = SB800_PM_SMBUS0EN_LO;
    564 		mask = SB800_PM_SMBUS0_MASK_C;
    565 	}
    566 
    567 	reg = piixpm_sb800_pmread(sc, index);
    568 
    569 	old_sda = __SHIFTOUT(reg, mask);
    570 	if (smbus->sda != old_sda) {
    571 		reg &= ~mask;
    572 		reg |= __SHIFTIN(smbus->sda, mask);
    573 		/*
    574 		 * SB800_INDIRECTIO_INDEX is already set on I/O access,
    575 		 * so it's not required to write it again.
    576 		 */
    577 		bus_space_write_1(sc->sc_sb800_bt, sc->sc_sb800_bh,
    578 		    sc->sc_sb800_mmio ? index : SB800_INDIRECTIO_DATA, reg);
    579 	}
    580 
    581 	/* Save the old port number */
    582 	smbus->sda_save = old_sda;
    583 
    584 	return 0;
    585 }
    586 
    587 static void
    588 piixpm_i2c_sb800_release_bus(void *cookie, int flags)
    589 {
    590 	struct piixpm_smbus *smbus = cookie;
    591 	struct piixpm_softc *sc = smbus->softc;
    592 	uint8_t sctl, index, mask, reg;
    593 
    594 	if (PIIXPM_IS_KERNCZ(sc) ||
    595 	    (PIIXPM_IS_HUDSON(sc) && (sc->sc_rev >= 0x1f))) {
    596 		index = AMDFCH41_PM_PORT_INDEX;
    597 		mask = AMDFCH41_SMBUS_PORTMASK;
    598 	} else if (sc->sc_sb800_selen) {
    599 		index = SB800_PM_SMBUS0SEL;
    600 		mask = SB800_PM_SMBUS0_MASK_E;
    601 	} else {
    602 		index = SB800_PM_SMBUS0EN_LO;
    603 		mask = SB800_PM_SMBUS0_MASK_C;
    604 	}
    605 
    606 	if (smbus->sda != smbus->sda_save) {
    607 		/* Restore the port number */
    608 		reg = piixpm_sb800_pmread(sc, index);
    609 		reg &= ~mask;
    610 		reg |= __SHIFTIN(smbus->sda_save, mask);
    611 		/*
    612 		 * SB800_INDIRECTIO_INDEX is already set on I/O access,
    613 		 * so it's not required to write it again.
    614 		 */
    615 		bus_space_write_1(sc->sc_sb800_bt, sc->sc_sb800_bh,
    616 		    sc->sc_sb800_mmio ? index : SB800_INDIRECTIO_DATA, reg);
    617 	}
    618 
    619 	/* Release the host semaphore */
    620 	sctl = bus_space_read_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_SC);
    621 	sctl &= ~PIIX_SMB_SC_SEMMASK;
    622 	bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_SC,
    623 	    sctl | PIIX_SMB_SC_CLRHOSTSEM);
    624 }
    625 
    626 static int
    627 piixpm_i2c_exec(void *cookie, i2c_op_t op, i2c_addr_t addr,
    628     const void *cmdbuf, size_t cmdlen, void *buf, size_t len, int flags)
    629 {
    630 	struct piixpm_smbus *smbus = cookie;
    631 	struct piixpm_softc *sc = smbus->softc;
    632 	const uint8_t *b;
    633 	uint8_t ctl = 0, st;
    634 	int retries;
    635 
    636 	DPRINTF(("%s: exec: op %d, addr 0x%02x, cmdlen %zu, len %zu, "
    637 		"flags 0x%x\n",
    638 		device_xname(sc->sc_dev), op, addr, cmdlen, len, flags));
    639 
    640 	mutex_enter(&sc->sc_exec_lock);
    641 
    642 	/* Clear status bits */
    643 	bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_HS,
    644 	    PIIX_SMB_HS_INTR | PIIX_SMB_HS_DEVERR |
    645 	    PIIX_SMB_HS_BUSERR | PIIX_SMB_HS_FAILED);
    646 	bus_space_barrier(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_HS, 1,
    647 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
    648 
    649 	/* Wait for bus to be idle */
    650 	for (retries = 100; retries > 0; retries--) {
    651 		st = bus_space_read_1(sc->sc_iot, sc->sc_smb_ioh,
    652 		    PIIX_SMB_HS);
    653 		if (!(st & PIIX_SMB_HS_BUSY))
    654 			break;
    655 		DELAY(PIIXPM_DELAY);
    656 	}
    657 	DPRINTF(("%s: exec: st %#x\n", device_xname(sc->sc_dev), st & 0xff));
    658 	if (st & PIIX_SMB_HS_BUSY) {
    659 		mutex_exit(&sc->sc_exec_lock);
    660 		return (EBUSY);
    661 	}
    662 
    663 	if (sc->sc_poll)
    664 		flags |= I2C_F_POLL;
    665 
    666 	if (!I2C_OP_STOP_P(op) || cmdlen > 1 || len > 2 ||
    667 	    (cmdlen == 0 && len > 1)) {
    668 		mutex_exit(&sc->sc_exec_lock);
    669 		return (EINVAL);
    670 	}
    671 
    672 	/* Setup transfer */
    673 	sc->sc_i2c_xfer.op = op;
    674 	sc->sc_i2c_xfer.buf = buf;
    675 	sc->sc_i2c_xfer.len = len;
    676 	sc->sc_i2c_xfer.flags = flags;
    677 	sc->sc_i2c_xfer.error = 0;
    678 	sc->sc_i2c_xfer.done = false;
    679 
    680 	/* Set slave address and transfer direction */
    681 	bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_TXSLVA,
    682 	    PIIX_SMB_TXSLVA_ADDR(addr) |
    683 	    (I2C_OP_READ_P(op) ? PIIX_SMB_TXSLVA_READ : 0));
    684 
    685 	b = cmdbuf;
    686 	if (cmdlen > 0)
    687 		/* Set command byte */
    688 		bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh,
    689 		    PIIX_SMB_HCMD, b[0]);
    690 
    691 	if (I2C_OP_WRITE_P(op)) {
    692 		/* Write data */
    693 		b = buf;
    694 		if (cmdlen == 0 && len == 1)
    695 			bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh,
    696 			    PIIX_SMB_HCMD, b[0]);
    697 		else if (len > 0)
    698 			bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh,
    699 			    PIIX_SMB_HD0, b[0]);
    700 		if (len > 1)
    701 			bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh,
    702 			    PIIX_SMB_HD1, b[1]);
    703 	}
    704 
    705 	/* Set SMBus command */
    706 	if (cmdlen == 0) {
    707 		if (len == 0)
    708 			ctl = PIIX_SMB_HC_CMD_QUICK;
    709 		else
    710 			ctl = PIIX_SMB_HC_CMD_BYTE;
    711 	} else if (len == 1)
    712 		ctl = PIIX_SMB_HC_CMD_BDATA;
    713 	else if (len == 2)
    714 		ctl = PIIX_SMB_HC_CMD_WDATA;
    715 	else
    716 		panic("%s: unexpected len %zu", __func__, len);
    717 
    718 	if ((flags & I2C_F_POLL) == 0)
    719 		ctl |= PIIX_SMB_HC_INTREN;
    720 
    721 	/* Start transaction */
    722 	ctl |= PIIX_SMB_HC_START;
    723 	bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_HC, ctl);
    724 
    725 	if (flags & I2C_F_POLL) {
    726 		/* Poll for completion */
    727 		if (PIIXPM_IS_CSB5(sc))
    728 			DELAY(2*PIIXPM_DELAY);
    729 		else
    730 			DELAY(PIIXPM_DELAY);
    731 		for (retries = 1000; retries > 0; retries--) {
    732 			st = bus_space_read_1(sc->sc_iot, sc->sc_smb_ioh,
    733 			    PIIX_SMB_HS);
    734 			if ((st & PIIX_SMB_HS_BUSY) == 0)
    735 				break;
    736 			DELAY(PIIXPM_DELAY);
    737 		}
    738 		if (st & PIIX_SMB_HS_BUSY)
    739 			goto timeout;
    740 		piixpm_intr(sc);
    741 	} else {
    742 		/* Wait for interrupt */
    743 		while (! sc->sc_i2c_xfer.done) {
    744 			if (cv_timedwait(&sc->sc_exec_wait, &sc->sc_exec_lock,
    745 					 PIIXPM_TIMEOUT * hz))
    746 				goto timeout;
    747 		}
    748 	}
    749 
    750 	int error = sc->sc_i2c_xfer.error;
    751 	mutex_exit(&sc->sc_exec_lock);
    752 
    753 	return (error);
    754 
    755 timeout:
    756 	/*
    757 	 * Transfer timeout. Kill the transaction and clear status bits.
    758 	 */
    759 	aprint_error_dev(sc->sc_dev, "timeout, status 0x%x\n", st);
    760 	bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_HC,
    761 	    PIIX_SMB_HC_KILL);
    762 	DELAY(PIIXPM_DELAY);
    763 	st = bus_space_read_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
    764 	if ((st & PIIX_SMB_HS_FAILED) == 0)
    765 		aprint_error_dev(sc->sc_dev,
    766 		    "transaction abort failed, status 0x%x\n", st);
    767 	bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
    768 	/*
    769 	 * CSB5 needs hard reset to unlock the smbus after timeout.
    770 	 */
    771 	if (PIIXPM_IS_CSB5(sc))
    772 		piixpm_csb5_reset(sc);
    773 	mutex_exit(&sc->sc_exec_lock);
    774 	return (ETIMEDOUT);
    775 }
    776 
    777 static int
    778 piixpm_intr(void *arg)
    779 {
    780 	struct piixpm_softc *sc = arg;
    781 	uint8_t st;
    782 	uint8_t *b;
    783 	size_t len;
    784 
    785 	/* Read status */
    786 	st = bus_space_read_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_HS);
    787 	if ((st & PIIX_SMB_HS_BUSY) != 0 || (st & (PIIX_SMB_HS_INTR |
    788 	    PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
    789 	    PIIX_SMB_HS_FAILED)) == 0)
    790 		/* Interrupt was not for us */
    791 		return (0);
    792 
    793 	DPRINTF(("%s: intr st %#x\n", device_xname(sc->sc_dev), st & 0xff));
    794 
    795 	if ((sc->sc_i2c_xfer.flags & I2C_F_POLL) == 0)
    796 		mutex_enter(&sc->sc_exec_lock);
    797 
    798 	/* Clear status bits */
    799 	bus_space_write_1(sc->sc_iot, sc->sc_smb_ioh, PIIX_SMB_HS, st);
    800 
    801 	/* Check for errors */
    802 	if (st & (PIIX_SMB_HS_DEVERR | PIIX_SMB_HS_BUSERR |
    803 	    PIIX_SMB_HS_FAILED)) {
    804 		sc->sc_i2c_xfer.error = EIO;
    805 		goto done;
    806 	}
    807 
    808 	if (st & PIIX_SMB_HS_INTR) {
    809 		if (I2C_OP_WRITE_P(sc->sc_i2c_xfer.op))
    810 			goto done;
    811 
    812 		/* Read data */
    813 		b = sc->sc_i2c_xfer.buf;
    814 		len = sc->sc_i2c_xfer.len;
    815 		if (len > 0)
    816 			b[0] = bus_space_read_1(sc->sc_iot, sc->sc_smb_ioh,
    817 			    PIIX_SMB_HD0);
    818 		if (len > 1)
    819 			b[1] = bus_space_read_1(sc->sc_iot, sc->sc_smb_ioh,
    820 			    PIIX_SMB_HD1);
    821 	}
    822 
    823 done:
    824 	sc->sc_i2c_xfer.done = true;
    825 	if ((sc->sc_i2c_xfer.flags & I2C_F_POLL) == 0) {
    826 		cv_signal(&sc->sc_exec_wait);
    827 		mutex_exit(&sc->sc_exec_lock);
    828 	}
    829 	return (1);
    830 }
    831