xref: /freebsd/sys/dev/glxiic/glxiic.c (revision a2aef24aa3c8458e4036735dd6928b4ef77294e5)
1 /*-
2  * Copyright (c) 2011 Henrik Brix Andersen <brix@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 /*
29  * AMD Geode LX CS5536 System Management Bus controller.
30  *
31  * Although AMD refers to this device as an SMBus controller, it
32  * really is an I2C controller (It lacks SMBus ALERT# and Alert
33  * Response support).
34  *
35  * The driver is implemented as an interrupt-driven state machine,
36  * supporting both master and slave mode.
37  */
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/bus.h>
41 #include <sys/kernel.h>
42 #include <sys/module.h>
43 #include <sys/lock.h>
44 #include <sys/mutex.h>
45 #include <sys/sysctl.h>
46 #ifdef GLXIIC_DEBUG
47 #include <sys/syslog.h>
48 #endif
49 
50 #include <dev/pci/pcireg.h>
51 #include <dev/pci/pcivar.h>
52 
53 #include <machine/bus.h>
54 #include <sys/rman.h>
55 #include <machine/resource.h>
56 
57 #include <dev/iicbus/iiconf.h>
58 #include <dev/iicbus/iicbus.h>
59 
60 #include "iicbus_if.h"
61 
62 /* CS5536 PCI-ISA ID. */
63 #define	GLXIIC_CS5536_DEV_ID		0x20901022
64 
65 /* MSRs. */
66 #define	GLXIIC_MSR_PIC_YSEL_HIGH	0x51400021
67 
68 /* Bus speeds. */
69 #define	GLXIIC_SLOW	0x0258	/*  10 kHz. */
70 #define	GLXIIC_FAST	0x0078	/*  50 kHz. */
71 #define	GLXIIC_FASTEST	0x003c	/* 100 kHz. */
72 
73 /* Default bus activity timeout in milliseconds. */
74 #define GLXIIC_DEFAULT_TIMEOUT	35
75 
76 /* GPIO register offsets. */
77 #define	GLXIIC_GPIOL_OUT_AUX1_SEL	0x10
78 #define	GLXIIC_GPIOL_IN_AUX1_SEL	0x34
79 
80 /* GPIO 14 (SMB_CLK) and 15 (SMB_DATA) bitmasks. */
81 #define	GLXIIC_GPIO_14_15_ENABLE	0x0000c000
82 #define	GLXIIC_GPIO_14_15_DISABLE	0xc0000000
83 
84 /* SMB register offsets. */
85 #define	GLXIIC_SMB_SDA				0x00
86 #define	GLXIIC_SMB_STS				0x01
87 #define		GLXIIC_SMB_STS_SLVSTP_BIT	(1 << 7)
88 #define		GLXIIC_SMB_STS_SDAST_BIT	(1 << 6)
89 #define		GLXIIC_SMB_STS_BER_BIT		(1 << 5)
90 #define		GLXIIC_SMB_STS_NEGACK_BIT	(1 << 4)
91 #define		GLXIIC_SMB_STS_STASTR_BIT	(1 << 3)
92 #define		GLXIIC_SMB_STS_NMATCH_BIT	(1 << 2)
93 #define		GLXIIC_SMB_STS_MASTER_BIT	(1 << 1)
94 #define		GLXIIC_SMB_STS_XMIT_BIT		(1 << 0)
95 #define	GLXIIC_SMB_CTRL_STS			0x02
96 #define		GLXIIC_SMB_CTRL_STS_TGSCL_BIT	(1 << 5)
97 #define		GLXIIC_SMB_CTRL_STS_TSDA_BIT	(1 << 4)
98 #define		GLXIIC_SMB_CTRL_STS_GCMTCH_BIT	(1 << 3)
99 #define		GLXIIC_SMB_CTRL_STS_MATCH_BIT	(1 << 2)
100 #define		GLXIIC_SMB_CTRL_STS_BB_BIT	(1 << 1)
101 #define		GLXIIC_SMB_CTRL_STS_BUSY_BIT	(1 << 0)
102 #define	GLXIIC_SMB_CTRL1			0x03
103 #define		GLXIIC_SMB_CTRL1_STASTRE_BIT	(1 << 7)
104 #define		GLXIIC_SMB_CTRL1_NMINTE_BIT	(1 << 6)
105 #define		GLXIIC_SMB_CTRL1_GCMEN_BIT	(1 << 5)
106 #define		GLXIIC_SMB_CTRL1_ACK_BIT	(1 << 4)
107 #define		GLXIIC_SMB_CTRL1_INTEN_BIT	(1 << 2)
108 #define		GLXIIC_SMB_CTRL1_STOP_BIT	(1 << 1)
109 #define		GLXIIC_SMB_CTRL1_START_BIT	(1 << 0)
110 #define	GLXIIC_SMB_ADDR				0x04
111 #define		GLXIIC_SMB_ADDR_SAEN_BIT	(1 << 7)
112 #define	GLXIIC_SMB_CTRL2			0x05
113 #define		GLXIIC_SMB_CTRL2_EN_BIT		(1 << 0)
114 #define	GLXIIC_SMB_CTRL3			0x06
115 
116 typedef enum {
117 	GLXIIC_STATE_IDLE,
118 	GLXIIC_STATE_SLAVE_TX,
119 	GLXIIC_STATE_SLAVE_RX,
120 	GLXIIC_STATE_MASTER_ADDR,
121 	GLXIIC_STATE_MASTER_TX,
122 	GLXIIC_STATE_MASTER_RX,
123 	GLXIIC_STATE_MASTER_STOP,
124 	GLXIIC_STATE_MAX,
125 } glxiic_state_t;
126 
127 struct glxiic_softc {
128 	device_t	 dev;		/* Myself. */
129 	device_t	 iicbus;	/* IIC bus. */
130 	struct mtx	 mtx;		/* Lock. */
131 	glxiic_state_t	 state;		/* Driver state. */
132 	struct callout	 callout;	/* Driver state timeout callout. */
133 	int		 timeout;	/* Driver state timeout (ms). */
134 
135 	int		 smb_rid;	/* SMB controller resource ID. */
136 	struct resource *smb_res;	/* SMB controller resource. */
137 	int		 gpio_rid;	/* GPIO resource ID. */
138 	struct resource *gpio_res;	/* GPIO resource. */
139 
140 	int		 irq_rid;	/* IRQ resource ID. */
141 	struct resource *irq_res;	/* IRQ resource. */
142 	void		*irq_handler;	/* IRQ handler cookie. */
143 	int		 old_irq;	/* IRQ mapped by board firmware. */
144 
145 	struct iic_msg	*msg;		/* Current master mode message. */
146 	uint32_t	 nmsgs;		/* Number of messages remaining. */
147 	uint8_t		*data;		/* Current master mode data byte. */
148 	uint16_t	 ndata;		/* Number of data bytes remaining. */
149 	int		 error;		/* Last master mode error. */
150 
151 	uint8_t		 addr;		/* Own address. */
152 	uint16_t	 sclfrq;	/* Bus frequency. */
153 };
154 
155 #ifdef GLXIIC_DEBUG
156 #define GLXIIC_DEBUG_LOG(fmt, args...)	\
157 	log(LOG_DEBUG, "%s: " fmt "\n" , __func__ , ## args)
158 #else
159 #define GLXIIC_DEBUG_LOG(fmt, args...)
160 #endif
161 
162 #define	GLXIIC_SCLFRQ(n)		((n << 1))
163 #define	GLXIIC_SMBADDR(n)		((n >> 1))
164 #define	GLXIIC_SMB_IRQ_TO_MAP(n)	((n << 16))
165 #define	GLXIIC_MAP_TO_SMB_IRQ(n)	((n >> 16) & 0xf)
166 
167 #define	GLXIIC_LOCK(_sc)		mtx_lock(&_sc->mtx)
168 #define	GLXIIC_UNLOCK(_sc)		mtx_unlock(&_sc->mtx)
169 #define	GLXIIC_LOCK_INIT(_sc)		\
170 	mtx_init(&_sc->mtx, device_get_nameunit(_sc->dev), "glxiic", MTX_DEF)
171 #define	GLXIIC_SLEEP(_sc)		\
172 	mtx_sleep(_sc, &_sc->mtx, IICPRI, "glxiic", 0)
173 #define	GLXIIC_WAKEUP(_sc)		wakeup(_sc);
174 #define	GLXIIC_LOCK_DESTROY(_sc)	mtx_destroy(&_sc->mtx);
175 #define	GLXIIC_ASSERT_LOCKED(_sc)	mtx_assert(&_sc->mtx, MA_OWNED);
176 
177 typedef	int (glxiic_state_callback_t)(struct glxiic_softc *sc,
178     uint8_t status);
179 
180 static glxiic_state_callback_t	glxiic_state_idle_callback;
181 static glxiic_state_callback_t	glxiic_state_slave_tx_callback;
182 static glxiic_state_callback_t	glxiic_state_slave_rx_callback;
183 static glxiic_state_callback_t	glxiic_state_master_addr_callback;
184 static glxiic_state_callback_t	glxiic_state_master_tx_callback;
185 static glxiic_state_callback_t	glxiic_state_master_rx_callback;
186 static glxiic_state_callback_t	glxiic_state_master_stop_callback;
187 
188 struct glxiic_state_table_entry {
189 	glxiic_state_callback_t *callback;
190 	boolean_t master;
191 };
192 typedef struct glxiic_state_table_entry glxiic_state_table_entry_t;
193 
194 static glxiic_state_table_entry_t glxiic_state_table[GLXIIC_STATE_MAX] = {
195 	[GLXIIC_STATE_IDLE] = {
196 		.callback = &glxiic_state_idle_callback,
197 		.master = FALSE,
198 	},
199 
200 	[GLXIIC_STATE_SLAVE_TX] = {
201 		.callback = &glxiic_state_slave_tx_callback,
202 		.master = FALSE,
203 	},
204 
205 	[GLXIIC_STATE_SLAVE_RX] = {
206 		.callback = &glxiic_state_slave_rx_callback,
207 		.master = FALSE,
208 	},
209 
210 	[GLXIIC_STATE_MASTER_ADDR] = {
211 		.callback = &glxiic_state_master_addr_callback,
212 		.master = TRUE,
213 	},
214 
215 	[GLXIIC_STATE_MASTER_TX] = {
216 		.callback = &glxiic_state_master_tx_callback,
217 		.master = TRUE,
218 	},
219 
220 	[GLXIIC_STATE_MASTER_RX] = {
221 		.callback = &glxiic_state_master_rx_callback,
222 		.master = TRUE,
223 	},
224 
225 	[GLXIIC_STATE_MASTER_STOP] = {
226 		.callback = &glxiic_state_master_stop_callback,
227 		.master = TRUE,
228 	},
229 };
230 
231 static void	glxiic_identify(driver_t *driver, device_t parent);
232 static int	glxiic_probe(device_t dev);
233 static int	glxiic_attach(device_t dev);
234 static int	glxiic_detach(device_t dev);
235 
236 static uint8_t	glxiic_read_status_locked(struct glxiic_softc *sc);
237 static void	glxiic_stop_locked(struct glxiic_softc *sc);
238 static void	glxiic_timeout(void *arg);
239 static void	glxiic_start_timeout_locked(struct glxiic_softc *sc);
240 static void	glxiic_set_state_locked(struct glxiic_softc *sc,
241     glxiic_state_t state);
242 static int	glxiic_handle_slave_match_locked(struct glxiic_softc *sc,
243     uint8_t status);
244 static void	glxiic_intr(void *arg);
245 
246 static int	glxiic_reset(device_t dev, u_char speed, u_char addr,
247     u_char *oldaddr);
248 static int	glxiic_transfer(device_t dev, struct iic_msg *msgs,
249     uint32_t nmsgs);
250 
251 static void	glxiic_smb_map_interrupt(int irq);
252 static void 	glxiic_gpio_enable(struct glxiic_softc *sc);
253 static void 	glxiic_gpio_disable(struct glxiic_softc *sc);
254 static void	glxiic_smb_enable(struct glxiic_softc *sc, uint8_t speed,
255     uint8_t addr);
256 static void	glxiic_smb_disable(struct glxiic_softc *sc);
257 
258 static device_method_t glxiic_methods[] = {
259 	DEVMETHOD(device_identify,	glxiic_identify),
260 	DEVMETHOD(device_probe,		glxiic_probe),
261 	DEVMETHOD(device_attach,	glxiic_attach),
262 	DEVMETHOD(device_detach,	glxiic_detach),
263 
264 	DEVMETHOD(iicbus_reset,		glxiic_reset),
265 	DEVMETHOD(iicbus_transfer,	glxiic_transfer),
266 	DEVMETHOD(iicbus_callback,	iicbus_null_callback),
267 
268 	{ 0, 0 }
269 };
270 
271 static driver_t glxiic_driver = {
272 	"glxiic",
273 	glxiic_methods,
274 	sizeof(struct glxiic_softc),
275 };
276 
277 static devclass_t glxiic_devclass;
278 
279 DRIVER_MODULE(glxiic, isab, glxiic_driver, glxiic_devclass, 0, 0);
280 DRIVER_MODULE(iicbus, glxiic, iicbus_driver, iicbus_devclass, 0, 0);
281 MODULE_DEPEND(glxiic, iicbus, 1, 1, 1);
282 
283 static void
284 glxiic_identify(driver_t *driver, device_t parent)
285 {
286 
287 	/* Prevent child from being added more than once. */
288 	if (device_find_child(parent, driver->name, -1) != NULL)
289 		return;
290 
291 	if (pci_get_devid(parent) == GLXIIC_CS5536_DEV_ID) {
292 		if (device_add_child(parent, driver->name, -1) == NULL)
293 			device_printf(parent, "Could not add glxiic child\n");
294 	}
295 }
296 
297 static int
298 glxiic_probe(device_t dev)
299 {
300 
301 	if (resource_disabled("glxiic", device_get_unit(dev)))
302 		return (ENXIO);
303 
304 	device_set_desc(dev, "AMD Geode CS5536 SMBus controller");
305 
306 	return (BUS_PROBE_DEFAULT);
307 }
308 
309 static int
310 glxiic_attach(device_t dev)
311 {
312 	struct glxiic_softc *sc;
313 	struct sysctl_ctx_list *ctx;
314 	struct sysctl_oid *tree;
315 	int error, irq, unit;
316 	uint32_t irq_map;
317 
318 	sc = device_get_softc(dev);
319 	sc->dev = dev;
320 	sc->state = GLXIIC_STATE_IDLE;
321 	error = 0;
322 
323 	GLXIIC_LOCK_INIT(sc);
324 	callout_init_mtx(&sc->callout, &sc->mtx, 0);
325 
326 	sc->smb_rid = PCIR_BAR(0);
327 	sc->smb_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &sc->smb_rid,
328 	    RF_ACTIVE);
329 	if (sc->smb_res == NULL) {
330 		device_printf(dev, "Could not allocate SMBus I/O port\n");
331 		error = ENXIO;
332 		goto out;
333 	}
334 
335 	sc->gpio_rid = PCIR_BAR(1);
336 	sc->gpio_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
337 	    &sc->gpio_rid, RF_SHAREABLE | RF_ACTIVE);
338 	if (sc->gpio_res == NULL) {
339 		device_printf(dev, "Could not allocate GPIO I/O port\n");
340 		error = ENXIO;
341 		goto out;
342 	}
343 
344 	/* Ensure the controller is not enabled by firmware. */
345 	glxiic_smb_disable(sc);
346 
347 	/* Read the existing IRQ map. */
348 	irq_map = rdmsr(GLXIIC_MSR_PIC_YSEL_HIGH);
349 	sc->old_irq = GLXIIC_MAP_TO_SMB_IRQ(irq_map);
350 
351 	unit = device_get_unit(dev);
352 	if (resource_int_value("glxiic", unit, "irq", &irq) == 0) {
353 		if (irq < 1 || irq > 15) {
354 			device_printf(dev, "Bad value %d for glxiic.%d.irq\n",
355 			    irq, unit);
356 			error = ENXIO;
357 			goto out;
358 		}
359 
360 		if (bootverbose)
361 			device_printf(dev, "Using irq %d set by hint\n", irq);
362 	} else if (sc->old_irq != 0) {
363 		if (bootverbose)
364 			device_printf(dev, "Using irq %d set by firmware\n",
365 			    irq);
366 		irq = sc->old_irq;
367 	} else {
368 		device_printf(dev, "No irq mapped by firmware");
369 		printf(" and no glxiic.%d.irq hint provided\n", unit);
370 		error = ENXIO;
371 		goto out;
372 	}
373 
374 	/* Map the SMBus interrupt to the requested legacy IRQ. */
375 	glxiic_smb_map_interrupt(irq);
376 
377 	sc->irq_rid = 0;
378 	sc->irq_res = bus_alloc_resource(dev, SYS_RES_IRQ, &sc->irq_rid,
379 	    irq, irq, 1, RF_SHAREABLE | RF_ACTIVE);
380 	if (sc->irq_res == NULL) {
381 		device_printf(dev, "Could not allocate IRQ %d\n", irq);
382 		error = ENXIO;
383 		goto out;
384 	}
385 
386 	error = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
387 	    NULL, glxiic_intr, sc, &(sc->irq_handler));
388 	if (error != 0) {
389 		device_printf(dev, "Could not setup IRQ handler\n");
390 		error = ENXIO;
391 		goto out;
392 	}
393 
394 	if ((sc->iicbus = device_add_child(dev, "iicbus", -1)) == NULL) {
395 		device_printf(dev, "Could not allocate iicbus instance\n");
396 		error = ENXIO;
397 		goto out;
398 	}
399 
400 	ctx = device_get_sysctl_ctx(dev);
401 	tree = device_get_sysctl_tree(dev);
402 
403 	sc->timeout = GLXIIC_DEFAULT_TIMEOUT;
404 	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
405 	    "timeout", CTLFLAG_RWTUN, &sc->timeout, 0,
406 	    "activity timeout in ms");
407 
408 	glxiic_gpio_enable(sc);
409 	glxiic_smb_enable(sc, IIC_FASTEST, 0);
410 
411 	/* Probe and attach the iicbus when interrupts are available. */
412 	config_intrhook_oneshot((ich_func_t)bus_generic_attach, dev);
413 	error = 0;
414 
415 out:
416 	if (error != 0) {
417 		callout_drain(&sc->callout);
418 
419 		if (sc->iicbus != NULL)
420 			device_delete_child(dev, sc->iicbus);
421 		if (sc->smb_res != NULL) {
422 			glxiic_smb_disable(sc);
423 			bus_release_resource(dev, SYS_RES_IOPORT, sc->smb_rid,
424 			    sc->smb_res);
425 		}
426 		if (sc->gpio_res != NULL) {
427 			glxiic_gpio_disable(sc);
428 			bus_release_resource(dev, SYS_RES_IOPORT, sc->gpio_rid,
429 			    sc->gpio_res);
430 		}
431 		if (sc->irq_handler != NULL)
432 			bus_teardown_intr(dev, sc->irq_res, sc->irq_handler);
433 		if (sc->irq_res != NULL)
434 			bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
435 			    sc->irq_res);
436 
437 		/* Restore the old SMBus interrupt mapping. */
438 		glxiic_smb_map_interrupt(sc->old_irq);
439 
440 		GLXIIC_LOCK_DESTROY(sc);
441 	}
442 
443 	return (error);
444 }
445 
446 static int
447 glxiic_detach(device_t dev)
448 {
449 	struct glxiic_softc *sc;
450 	int error;
451 
452 	sc = device_get_softc(dev);
453 
454 	error = bus_generic_detach(dev);
455 	if (error != 0)
456 		goto out;
457 	if (sc->iicbus != NULL)
458 		error = device_delete_child(dev, sc->iicbus);
459 
460 out:
461 	callout_drain(&sc->callout);
462 
463 	if (sc->smb_res != NULL) {
464 		glxiic_smb_disable(sc);
465 		bus_release_resource(dev, SYS_RES_IOPORT, sc->smb_rid,
466 		    sc->smb_res);
467 	}
468 	if (sc->gpio_res != NULL) {
469 		glxiic_gpio_disable(sc);
470 		bus_release_resource(dev, SYS_RES_IOPORT, sc->gpio_rid,
471 		    sc->gpio_res);
472 	}
473 	if (sc->irq_handler != NULL)
474 		bus_teardown_intr(dev, sc->irq_res, sc->irq_handler);
475 	if (sc->irq_res != NULL)
476 		bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
477 		    sc->irq_res);
478 
479 	/* Restore the old SMBus interrupt mapping. */
480 	glxiic_smb_map_interrupt(sc->old_irq);
481 
482 	GLXIIC_LOCK_DESTROY(sc);
483 
484 	return (error);
485 }
486 
487 static uint8_t
488 glxiic_read_status_locked(struct glxiic_softc *sc)
489 {
490 	uint8_t status;
491 
492 	GLXIIC_ASSERT_LOCKED(sc);
493 
494 	status = bus_read_1(sc->smb_res, GLXIIC_SMB_STS);
495 
496 	/* Clear all status flags except SDAST and STASTR after reading. */
497 	bus_write_1(sc->smb_res, GLXIIC_SMB_STS, (GLXIIC_SMB_STS_SLVSTP_BIT |
498 		GLXIIC_SMB_STS_BER_BIT | GLXIIC_SMB_STS_NEGACK_BIT |
499 		GLXIIC_SMB_STS_NMATCH_BIT));
500 
501 	return (status);
502 }
503 
504 static void
505 glxiic_stop_locked(struct glxiic_softc *sc)
506 {
507 	uint8_t status, ctrl1;
508 
509 	GLXIIC_ASSERT_LOCKED(sc);
510 
511 	status = glxiic_read_status_locked(sc);
512 
513 	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
514 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
515 	    ctrl1 | GLXIIC_SMB_CTRL1_STOP_BIT);
516 
517 	/*
518 	 * Perform a dummy read of SDA in master receive mode to clear
519 	 * SDAST if set.
520 	 */
521 	if ((status & GLXIIC_SMB_STS_XMIT_BIT) == 0 &&
522 	    (status & GLXIIC_SMB_STS_SDAST_BIT) != 0)
523 	 	bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
524 
525 	/* Check stall after start bit and clear if needed */
526 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
527 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
528 		    GLXIIC_SMB_STS_STASTR_BIT);
529 	}
530 }
531 
532 static void
533 glxiic_timeout(void *arg)
534 {
535 	struct glxiic_softc *sc;
536 	uint8_t error;
537 
538 	sc = (struct glxiic_softc *)arg;
539 
540 	GLXIIC_DEBUG_LOG("timeout in state %d", sc->state);
541 
542 	if (glxiic_state_table[sc->state].master) {
543 		sc->error = IIC_ETIMEOUT;
544 		GLXIIC_WAKEUP(sc);
545 	} else {
546 		error = IIC_ETIMEOUT;
547 		iicbus_intr(sc->iicbus, INTR_ERROR, &error);
548 	}
549 
550 	glxiic_smb_disable(sc);
551 	glxiic_smb_enable(sc, IIC_UNKNOWN, sc->addr);
552 	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
553 }
554 
555 static void
556 glxiic_start_timeout_locked(struct glxiic_softc *sc)
557 {
558 
559 	GLXIIC_ASSERT_LOCKED(sc);
560 
561 	callout_reset_sbt(&sc->callout, SBT_1MS * sc->timeout, 0,
562 	    glxiic_timeout, sc, 0);
563 }
564 
565 static void
566 glxiic_set_state_locked(struct glxiic_softc *sc, glxiic_state_t state)
567 {
568 
569 	GLXIIC_ASSERT_LOCKED(sc);
570 
571 	if (state == GLXIIC_STATE_IDLE)
572 		callout_stop(&sc->callout);
573 	else if (sc->timeout > 0)
574 		glxiic_start_timeout_locked(sc);
575 
576 	sc->state = state;
577 }
578 
579 static int
580 glxiic_handle_slave_match_locked(struct glxiic_softc *sc, uint8_t status)
581 {
582 	uint8_t ctrl_sts, addr;
583 
584 	GLXIIC_ASSERT_LOCKED(sc);
585 
586 	ctrl_sts = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL_STS);
587 
588 	if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_MATCH_BIT) != 0) {
589 		if ((status & GLXIIC_SMB_STS_XMIT_BIT) != 0) {
590 			addr = sc->addr | LSB;
591 			glxiic_set_state_locked(sc,
592 			    GLXIIC_STATE_SLAVE_TX);
593 		} else {
594 			addr = sc->addr & ~LSB;
595 			glxiic_set_state_locked(sc,
596 			    GLXIIC_STATE_SLAVE_RX);
597 		}
598 		iicbus_intr(sc->iicbus, INTR_START, &addr);
599 	} else if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_GCMTCH_BIT) != 0) {
600 		addr = 0;
601 		glxiic_set_state_locked(sc, GLXIIC_STATE_SLAVE_RX);
602 		iicbus_intr(sc->iicbus, INTR_GENERAL, &addr);
603 	} else {
604 		GLXIIC_DEBUG_LOG("unknown slave match");
605 		return (IIC_ESTATUS);
606 	}
607 
608 	return (IIC_NOERR);
609 }
610 
611 static int
612 glxiic_state_idle_callback(struct glxiic_softc *sc, uint8_t status)
613 {
614 
615 	GLXIIC_ASSERT_LOCKED(sc);
616 
617 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
618 		GLXIIC_DEBUG_LOG("bus error in idle");
619 		return (IIC_EBUSERR);
620 	}
621 
622 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
623 		return (glxiic_handle_slave_match_locked(sc, status));
624 	}
625 
626 	return (IIC_NOERR);
627 }
628 
629 static int
630 glxiic_state_slave_tx_callback(struct glxiic_softc *sc, uint8_t status)
631 {
632 	uint8_t data;
633 
634 	GLXIIC_ASSERT_LOCKED(sc);
635 
636 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
637 		GLXIIC_DEBUG_LOG("bus error in slave tx");
638 		return (IIC_EBUSERR);
639 	}
640 
641 	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
642 		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
643 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
644 		return (IIC_NOERR);
645 	}
646 
647 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
648 		iicbus_intr(sc->iicbus, INTR_NOACK, NULL);
649 		return (IIC_NOERR);
650 	}
651 
652 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
653 		/* Handle repeated start in slave mode. */
654 		return (glxiic_handle_slave_match_locked(sc, status));
655 	}
656 
657 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
658 		GLXIIC_DEBUG_LOG("not awaiting data in slave tx");
659 		return (IIC_ESTATUS);
660 	}
661 
662 	iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data);
663 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, data);
664 
665 	glxiic_start_timeout_locked(sc);
666 
667 	return (IIC_NOERR);
668 }
669 
670 static int
671 glxiic_state_slave_rx_callback(struct glxiic_softc *sc, uint8_t status)
672 {
673 	uint8_t data;
674 
675 	GLXIIC_ASSERT_LOCKED(sc);
676 
677 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
678 		GLXIIC_DEBUG_LOG("bus error in slave rx");
679 		return (IIC_EBUSERR);
680 	}
681 
682 	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
683 		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
684 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
685 		return (IIC_NOERR);
686 	}
687 
688 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
689 		/* Handle repeated start in slave mode. */
690 		return (glxiic_handle_slave_match_locked(sc, status));
691 	}
692 
693 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
694 		GLXIIC_DEBUG_LOG("no pending data in slave rx");
695 		return (IIC_ESTATUS);
696 	}
697 
698 	data = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
699 	iicbus_intr(sc->iicbus, INTR_RECEIVE, &data);
700 
701 	glxiic_start_timeout_locked(sc);
702 
703 	return (IIC_NOERR);
704 }
705 
706 static int
707 glxiic_state_master_addr_callback(struct glxiic_softc *sc, uint8_t status)
708 {
709 	uint8_t slave;
710 	uint8_t ctrl1;
711 
712 	GLXIIC_ASSERT_LOCKED(sc);
713 
714 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
715 		GLXIIC_DEBUG_LOG("bus error after master start");
716 		return (IIC_EBUSERR);
717 	}
718 
719 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
720 		GLXIIC_DEBUG_LOG("not bus master after master start");
721 		return (IIC_ESTATUS);
722 	}
723 
724 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
725 		GLXIIC_DEBUG_LOG("not awaiting address in master addr");
726 		return (IIC_ESTATUS);
727 	}
728 
729 	if ((sc->msg->flags & IIC_M_RD) != 0) {
730 		slave = sc->msg->slave | LSB;
731 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_RX);
732 	} else {
733 		slave = sc->msg->slave & ~LSB;
734 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_TX);
735 	}
736 
737 	sc->data = sc->msg->buf;
738 	sc->ndata = sc->msg->len;
739 
740 	/* Handle address-only transfer. */
741 	if (sc->ndata == 0)
742 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
743 
744 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, slave);
745 
746 	if ((sc->msg->flags & IIC_M_RD) != 0 && sc->ndata == 1) {
747 		/* Last byte from slave, set NACK. */
748 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
749 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
750 		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
751 	}
752 
753 	return (IIC_NOERR);
754 }
755 
756 static int
757 glxiic_state_master_tx_callback(struct glxiic_softc *sc, uint8_t status)
758 {
759 
760 	GLXIIC_ASSERT_LOCKED(sc);
761 
762 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
763 		GLXIIC_DEBUG_LOG("bus error in master tx");
764 		return (IIC_EBUSERR);
765 	}
766 
767 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
768 		GLXIIC_DEBUG_LOG("not bus master in master tx");
769 		return (IIC_ESTATUS);
770 	}
771 
772 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
773 		GLXIIC_DEBUG_LOG("slave nack in master tx");
774 		return (IIC_ENOACK);
775 	}
776 
777 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
778 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
779 		    GLXIIC_SMB_STS_STASTR_BIT);
780 	}
781 
782 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
783 		GLXIIC_DEBUG_LOG("not awaiting data in master tx");
784 		return (IIC_ESTATUS);
785 	}
786 
787 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, *sc->data++);
788 	if (--sc->ndata == 0)
789 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
790 	else
791 		glxiic_start_timeout_locked(sc);
792 
793 	return (IIC_NOERR);
794 }
795 
796 static int
797 glxiic_state_master_rx_callback(struct glxiic_softc *sc, uint8_t status)
798 {
799 	uint8_t ctrl1;
800 
801 	GLXIIC_ASSERT_LOCKED(sc);
802 
803 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
804 		GLXIIC_DEBUG_LOG("bus error in master rx");
805 		return (IIC_EBUSERR);
806 	}
807 
808 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
809 		GLXIIC_DEBUG_LOG("not bus master in master rx");
810 		return (IIC_ESTATUS);
811 	}
812 
813 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
814 		GLXIIC_DEBUG_LOG("slave nack in rx");
815 		return (IIC_ENOACK);
816 	}
817 
818 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
819 		/* Bus is stalled, clear and wait for data. */
820 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
821 		    GLXIIC_SMB_STS_STASTR_BIT);
822 		return (IIC_NOERR);
823 	}
824 
825 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
826 		GLXIIC_DEBUG_LOG("no pending data in master rx");
827 		return (IIC_ESTATUS);
828 	}
829 
830 	*sc->data++ = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
831 	if (--sc->ndata == 0) {
832 		/* Proceed with stop on reading last byte. */
833 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
834 		return (glxiic_state_table[sc->state].callback(sc, status));
835 	}
836 
837 	if (sc->ndata == 1) {
838 		/* Last byte from slave, set NACK. */
839 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
840 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
841 		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
842 	}
843 
844 	glxiic_start_timeout_locked(sc);
845 
846 	return (IIC_NOERR);
847 }
848 
849 static int
850 glxiic_state_master_stop_callback(struct glxiic_softc *sc, uint8_t status)
851 {
852 	uint8_t ctrl1;
853 
854 	GLXIIC_ASSERT_LOCKED(sc);
855 
856 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
857 		GLXIIC_DEBUG_LOG("bus error in master stop");
858 		return (IIC_EBUSERR);
859 	}
860 
861 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
862 		GLXIIC_DEBUG_LOG("not bus master in master stop");
863 		return (IIC_ESTATUS);
864 	}
865 
866 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
867 		GLXIIC_DEBUG_LOG("slave nack in master stop");
868 		return (IIC_ENOACK);
869 	}
870 
871 	if (--sc->nmsgs > 0) {
872 		/* Start transfer of next message. */
873 		if ((sc->msg->flags & IIC_M_NOSTOP) == 0) {
874 			glxiic_stop_locked(sc);
875 		}
876 
877 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
878 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
879 		    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
880 
881 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
882 		sc->msg++;
883 	} else {
884 		/* Last message. */
885 		glxiic_stop_locked(sc);
886 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
887 		sc->error = IIC_NOERR;
888 		GLXIIC_WAKEUP(sc);
889 	}
890 
891 	return (IIC_NOERR);
892 }
893 
894 static void
895 glxiic_intr(void *arg)
896 {
897 	struct glxiic_softc *sc;
898 	int error;
899 	uint8_t status, data;
900 
901 	sc = (struct glxiic_softc *)arg;
902 
903 	GLXIIC_LOCK(sc);
904 
905 	status = glxiic_read_status_locked(sc);
906 
907 	/* Check if this interrupt originated from the SMBus. */
908 	if ((status &
909 		~(GLXIIC_SMB_STS_MASTER_BIT | GLXIIC_SMB_STS_XMIT_BIT)) != 0) {
910 
911 		error = glxiic_state_table[sc->state].callback(sc, status);
912 
913 		if (error != IIC_NOERR) {
914 			if (glxiic_state_table[sc->state].master) {
915 				glxiic_stop_locked(sc);
916 				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
917 				sc->error = error;
918 				GLXIIC_WAKEUP(sc);
919 			} else {
920 				data = error & 0xff;
921 				iicbus_intr(sc->iicbus, INTR_ERROR, &data);
922 				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
923 			}
924 		}
925 	}
926 
927 	GLXIIC_UNLOCK(sc);
928 }
929 
930 static int
931 glxiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
932 {
933 	struct glxiic_softc *sc;
934 
935 	sc = device_get_softc(dev);
936 
937 	GLXIIC_LOCK(sc);
938 
939 	if (oldaddr != NULL)
940 		*oldaddr = sc->addr;
941 	sc->addr = addr;
942 
943 	/* A disable/enable cycle resets the controller. */
944 	glxiic_smb_disable(sc);
945 	glxiic_smb_enable(sc, speed, addr);
946 
947 	if (glxiic_state_table[sc->state].master) {
948 		sc->error = IIC_ESTATUS;
949 		GLXIIC_WAKEUP(sc);
950 	}
951 	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
952 
953 	GLXIIC_UNLOCK(sc);
954 
955 	return (IIC_NOERR);
956 }
957 
958 static int
959 glxiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
960 {
961 	struct glxiic_softc *sc;
962 	int error;
963 	uint8_t ctrl1;
964 
965 	sc = device_get_softc(dev);
966 
967 	GLXIIC_LOCK(sc);
968 
969 	if (sc->state != GLXIIC_STATE_IDLE) {
970 		error = IIC_EBUSBSY;
971 		goto out;
972 	}
973 
974 	sc->msg = msgs;
975 	sc->nmsgs = nmsgs;
976 	glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
977 
978 	/* Set start bit and let glxiic_intr() handle the transfer. */
979 	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
980 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
981 	    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
982 
983 	GLXIIC_SLEEP(sc);
984 	error = sc->error;
985 out:
986 	GLXIIC_UNLOCK(sc);
987 
988 	return (error);
989 }
990 
991 static void
992 glxiic_smb_map_interrupt(int irq)
993 {
994 	uint32_t irq_map;
995 	int old_irq;
996 
997 	/* Protect the read-modify-write operation. */
998 	critical_enter();
999 
1000 	irq_map = rdmsr(GLXIIC_MSR_PIC_YSEL_HIGH);
1001 	old_irq = GLXIIC_MAP_TO_SMB_IRQ(irq_map);
1002 
1003 	if (irq != old_irq) {
1004 		irq_map &= ~GLXIIC_SMB_IRQ_TO_MAP(old_irq);
1005 		irq_map |= GLXIIC_SMB_IRQ_TO_MAP(irq);
1006 		wrmsr(GLXIIC_MSR_PIC_YSEL_HIGH, irq_map);
1007 	}
1008 
1009 	critical_exit();
1010 }
1011 
1012 static void
1013 glxiic_gpio_enable(struct glxiic_softc *sc)
1014 {
1015 
1016 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1017 	    GLXIIC_GPIO_14_15_ENABLE);
1018 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1019 	    GLXIIC_GPIO_14_15_ENABLE);
1020 }
1021 
1022 static void
1023 glxiic_gpio_disable(struct glxiic_softc *sc)
1024 {
1025 
1026 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1027 	    GLXIIC_GPIO_14_15_DISABLE);
1028 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1029 	    GLXIIC_GPIO_14_15_DISABLE);
1030 }
1031 
1032 static void
1033 glxiic_smb_enable(struct glxiic_softc *sc, uint8_t speed, uint8_t addr)
1034 {
1035 	uint8_t ctrl1;
1036 
1037 	ctrl1 = 0;
1038 
1039 	switch (speed) {
1040 	case IIC_SLOW:
1041 		sc->sclfrq = GLXIIC_SLOW;
1042 		break;
1043 	case IIC_FAST:
1044 		sc->sclfrq = GLXIIC_FAST;
1045 		break;
1046 	case IIC_FASTEST:
1047 		sc->sclfrq = GLXIIC_FASTEST;
1048 		break;
1049 	case IIC_UNKNOWN:
1050 	default:
1051 		/* Reuse last frequency. */
1052 		break;
1053 	}
1054 
1055 	/* Set bus speed and enable controller. */
1056 	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1057 	    GLXIIC_SCLFRQ(sc->sclfrq) | GLXIIC_SMB_CTRL2_EN_BIT);
1058 
1059 	if (addr != 0) {
1060 		/* Enable new match and global call match interrupts. */
1061 		ctrl1 |= GLXIIC_SMB_CTRL1_NMINTE_BIT |
1062 			GLXIIC_SMB_CTRL1_GCMEN_BIT;
1063 		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR,
1064 		    GLXIIC_SMB_ADDR_SAEN_BIT | GLXIIC_SMBADDR(addr));
1065 	} else {
1066 		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR, 0);
1067 	}
1068 
1069 	/* Enable stall after start and interrupt. */
1070 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
1071 	    ctrl1 | GLXIIC_SMB_CTRL1_STASTRE_BIT | GLXIIC_SMB_CTRL1_INTEN_BIT);
1072 }
1073 
1074 static void
1075 glxiic_smb_disable(struct glxiic_softc *sc)
1076 {
1077 	uint16_t sclfrq;
1078 
1079 	sclfrq = bus_read_2(sc->smb_res, GLXIIC_SMB_CTRL2);
1080 	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1081 	    sclfrq & ~GLXIIC_SMB_CTRL2_EN_BIT);
1082 }
1083