xref: /freebsd/sys/dev/glxiic/glxiic.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2011 Henrik Brix Andersen <brix@FreeBSD.org>
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 AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 /*
31  * AMD Geode LX CS5536 System Management Bus controller.
32  *
33  * Although AMD refers to this device as an SMBus controller, it
34  * really is an I2C controller (It lacks SMBus ALERT# and Alert
35  * Response support).
36  *
37  * The driver is implemented as an interrupt-driven state machine,
38  * supporting both master and slave mode.
39  */
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/bus.h>
43 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/sysctl.h>
48 #ifdef GLXIIC_DEBUG
49 #include <sys/syslog.h>
50 #endif
51 
52 #include <dev/pci/pcireg.h>
53 #include <dev/pci/pcivar.h>
54 
55 #include <machine/bus.h>
56 #include <sys/rman.h>
57 #include <machine/resource.h>
58 
59 #include <dev/iicbus/iiconf.h>
60 #include <dev/iicbus/iicbus.h>
61 
62 #include "iicbus_if.h"
63 
64 /* CS5536 PCI-ISA ID. */
65 #define	GLXIIC_CS5536_DEV_ID		0x20901022
66 
67 /* MSRs. */
68 #define	GLXIIC_MSR_PIC_YSEL_HIGH	0x51400021
69 
70 /* Bus speeds. */
71 #define	GLXIIC_SLOW	0x0258	/*  10 kHz. */
72 #define	GLXIIC_FAST	0x0078	/*  50 kHz. */
73 #define	GLXIIC_FASTEST	0x003c	/* 100 kHz. */
74 
75 /* Default bus activity timeout in milliseconds. */
76 #define GLXIIC_DEFAULT_TIMEOUT	35
77 
78 /* GPIO register offsets. */
79 #define	GLXIIC_GPIOL_OUT_AUX1_SEL	0x10
80 #define	GLXIIC_GPIOL_IN_AUX1_SEL	0x34
81 
82 /* GPIO 14 (SMB_CLK) and 15 (SMB_DATA) bitmasks. */
83 #define	GLXIIC_GPIO_14_15_ENABLE	0x0000c000
84 #define	GLXIIC_GPIO_14_15_DISABLE	0xc0000000
85 
86 /* SMB register offsets. */
87 #define	GLXIIC_SMB_SDA				0x00
88 #define	GLXIIC_SMB_STS				0x01
89 #define		GLXIIC_SMB_STS_SLVSTP_BIT	(1 << 7)
90 #define		GLXIIC_SMB_STS_SDAST_BIT	(1 << 6)
91 #define		GLXIIC_SMB_STS_BER_BIT		(1 << 5)
92 #define		GLXIIC_SMB_STS_NEGACK_BIT	(1 << 4)
93 #define		GLXIIC_SMB_STS_STASTR_BIT	(1 << 3)
94 #define		GLXIIC_SMB_STS_NMATCH_BIT	(1 << 2)
95 #define		GLXIIC_SMB_STS_MASTER_BIT	(1 << 1)
96 #define		GLXIIC_SMB_STS_XMIT_BIT		(1 << 0)
97 #define	GLXIIC_SMB_CTRL_STS			0x02
98 #define		GLXIIC_SMB_CTRL_STS_TGSCL_BIT	(1 << 5)
99 #define		GLXIIC_SMB_CTRL_STS_TSDA_BIT	(1 << 4)
100 #define		GLXIIC_SMB_CTRL_STS_GCMTCH_BIT	(1 << 3)
101 #define		GLXIIC_SMB_CTRL_STS_MATCH_BIT	(1 << 2)
102 #define		GLXIIC_SMB_CTRL_STS_BB_BIT	(1 << 1)
103 #define		GLXIIC_SMB_CTRL_STS_BUSY_BIT	(1 << 0)
104 #define	GLXIIC_SMB_CTRL1			0x03
105 #define		GLXIIC_SMB_CTRL1_STASTRE_BIT	(1 << 7)
106 #define		GLXIIC_SMB_CTRL1_NMINTE_BIT	(1 << 6)
107 #define		GLXIIC_SMB_CTRL1_GCMEN_BIT	(1 << 5)
108 #define		GLXIIC_SMB_CTRL1_ACK_BIT	(1 << 4)
109 #define		GLXIIC_SMB_CTRL1_INTEN_BIT	(1 << 2)
110 #define		GLXIIC_SMB_CTRL1_STOP_BIT	(1 << 1)
111 #define		GLXIIC_SMB_CTRL1_START_BIT	(1 << 0)
112 #define	GLXIIC_SMB_ADDR				0x04
113 #define		GLXIIC_SMB_ADDR_SAEN_BIT	(1 << 7)
114 #define	GLXIIC_SMB_CTRL2			0x05
115 #define		GLXIIC_SMB_CTRL2_EN_BIT		(1 << 0)
116 #define	GLXIIC_SMB_CTRL3			0x06
117 
118 typedef enum {
119 	GLXIIC_STATE_IDLE,
120 	GLXIIC_STATE_SLAVE_TX,
121 	GLXIIC_STATE_SLAVE_RX,
122 	GLXIIC_STATE_MASTER_ADDR,
123 	GLXIIC_STATE_MASTER_TX,
124 	GLXIIC_STATE_MASTER_RX,
125 	GLXIIC_STATE_MASTER_STOP,
126 	GLXIIC_STATE_MAX,
127 } glxiic_state_t;
128 
129 struct glxiic_softc {
130 	device_t	 dev;		/* Myself. */
131 	device_t	 iicbus;	/* IIC bus. */
132 	struct mtx	 mtx;		/* Lock. */
133 	glxiic_state_t	 state;		/* Driver state. */
134 	struct callout	 callout;	/* Driver state timeout callout. */
135 	int		 timeout;	/* Driver state timeout (ms). */
136 
137 	int		 smb_rid;	/* SMB controller resource ID. */
138 	struct resource *smb_res;	/* SMB controller resource. */
139 	int		 gpio_rid;	/* GPIO resource ID. */
140 	struct resource *gpio_res;	/* GPIO resource. */
141 
142 	int		 irq_rid;	/* IRQ resource ID. */
143 	struct resource *irq_res;	/* IRQ resource. */
144 	void		*irq_handler;	/* IRQ handler cookie. */
145 	int		 old_irq;	/* IRQ mapped by board firmware. */
146 
147 	struct iic_msg	*msg;		/* Current master mode message. */
148 	uint32_t	 nmsgs;		/* Number of messages remaining. */
149 	uint8_t		*data;		/* Current master mode data byte. */
150 	uint16_t	 ndata;		/* Number of data bytes remaining. */
151 	int		 error;		/* Last master mode error. */
152 
153 	uint8_t		 addr;		/* Own address. */
154 	uint16_t	 sclfrq;	/* Bus frequency. */
155 };
156 
157 #ifdef GLXIIC_DEBUG
158 #define GLXIIC_DEBUG_LOG(fmt, args...)	\
159 	log(LOG_DEBUG, "%s: " fmt "\n" , __func__ , ## args)
160 #else
161 #define GLXIIC_DEBUG_LOG(fmt, args...)
162 #endif
163 
164 #define	GLXIIC_SCLFRQ(n)		((n << 1))
165 #define	GLXIIC_SMBADDR(n)		((n >> 1))
166 #define	GLXIIC_SMB_IRQ_TO_MAP(n)	((n << 16))
167 #define	GLXIIC_MAP_TO_SMB_IRQ(n)	((n >> 16) & 0xf)
168 
169 #define	GLXIIC_LOCK(_sc)		mtx_lock(&_sc->mtx)
170 #define	GLXIIC_UNLOCK(_sc)		mtx_unlock(&_sc->mtx)
171 #define	GLXIIC_LOCK_INIT(_sc)		\
172 	mtx_init(&_sc->mtx, device_get_nameunit(_sc->dev), "glxiic", MTX_DEF)
173 #define	GLXIIC_SLEEP(_sc)		\
174 	mtx_sleep(_sc, &_sc->mtx, IICPRI, "glxiic", 0)
175 #define	GLXIIC_WAKEUP(_sc)		wakeup(_sc);
176 #define	GLXIIC_LOCK_DESTROY(_sc)	mtx_destroy(&_sc->mtx);
177 #define	GLXIIC_ASSERT_LOCKED(_sc)	mtx_assert(&_sc->mtx, MA_OWNED);
178 
179 typedef	int (glxiic_state_callback_t)(struct glxiic_softc *sc,
180     uint8_t status);
181 
182 static glxiic_state_callback_t	glxiic_state_idle_callback;
183 static glxiic_state_callback_t	glxiic_state_slave_tx_callback;
184 static glxiic_state_callback_t	glxiic_state_slave_rx_callback;
185 static glxiic_state_callback_t	glxiic_state_master_addr_callback;
186 static glxiic_state_callback_t	glxiic_state_master_tx_callback;
187 static glxiic_state_callback_t	glxiic_state_master_rx_callback;
188 static glxiic_state_callback_t	glxiic_state_master_stop_callback;
189 
190 struct glxiic_state_table_entry {
191 	glxiic_state_callback_t *callback;
192 	boolean_t master;
193 };
194 typedef struct glxiic_state_table_entry glxiic_state_table_entry_t;
195 
196 static glxiic_state_table_entry_t glxiic_state_table[GLXIIC_STATE_MAX] = {
197 	[GLXIIC_STATE_IDLE] = {
198 		.callback = &glxiic_state_idle_callback,
199 		.master = FALSE,
200 	},
201 
202 	[GLXIIC_STATE_SLAVE_TX] = {
203 		.callback = &glxiic_state_slave_tx_callback,
204 		.master = FALSE,
205 	},
206 
207 	[GLXIIC_STATE_SLAVE_RX] = {
208 		.callback = &glxiic_state_slave_rx_callback,
209 		.master = FALSE,
210 	},
211 
212 	[GLXIIC_STATE_MASTER_ADDR] = {
213 		.callback = &glxiic_state_master_addr_callback,
214 		.master = TRUE,
215 	},
216 
217 	[GLXIIC_STATE_MASTER_TX] = {
218 		.callback = &glxiic_state_master_tx_callback,
219 		.master = TRUE,
220 	},
221 
222 	[GLXIIC_STATE_MASTER_RX] = {
223 		.callback = &glxiic_state_master_rx_callback,
224 		.master = TRUE,
225 	},
226 
227 	[GLXIIC_STATE_MASTER_STOP] = {
228 		.callback = &glxiic_state_master_stop_callback,
229 		.master = TRUE,
230 	},
231 };
232 
233 static void	glxiic_identify(driver_t *driver, device_t parent);
234 static int	glxiic_probe(device_t dev);
235 static int	glxiic_attach(device_t dev);
236 static int	glxiic_detach(device_t dev);
237 
238 static uint8_t	glxiic_read_status_locked(struct glxiic_softc *sc);
239 static void	glxiic_stop_locked(struct glxiic_softc *sc);
240 static void	glxiic_timeout(void *arg);
241 static void	glxiic_start_timeout_locked(struct glxiic_softc *sc);
242 static void	glxiic_set_state_locked(struct glxiic_softc *sc,
243     glxiic_state_t state);
244 static int	glxiic_handle_slave_match_locked(struct glxiic_softc *sc,
245     uint8_t status);
246 static void	glxiic_intr(void *arg);
247 
248 static int	glxiic_reset(device_t dev, u_char speed, u_char addr,
249     u_char *oldaddr);
250 static int	glxiic_transfer(device_t dev, struct iic_msg *msgs,
251     uint32_t nmsgs);
252 
253 static void	glxiic_smb_map_interrupt(int irq);
254 static void 	glxiic_gpio_enable(struct glxiic_softc *sc);
255 static void 	glxiic_gpio_disable(struct glxiic_softc *sc);
256 static void	glxiic_smb_enable(struct glxiic_softc *sc, uint8_t speed,
257     uint8_t addr);
258 static void	glxiic_smb_disable(struct glxiic_softc *sc);
259 
260 static device_method_t glxiic_methods[] = {
261 	DEVMETHOD(device_identify,	glxiic_identify),
262 	DEVMETHOD(device_probe,		glxiic_probe),
263 	DEVMETHOD(device_attach,	glxiic_attach),
264 	DEVMETHOD(device_detach,	glxiic_detach),
265 
266 	DEVMETHOD(iicbus_reset,		glxiic_reset),
267 	DEVMETHOD(iicbus_transfer,	glxiic_transfer),
268 	DEVMETHOD(iicbus_callback,	iicbus_null_callback),
269 
270 	{ 0, 0 }
271 };
272 
273 static driver_t glxiic_driver = {
274 	"glxiic",
275 	glxiic_methods,
276 	sizeof(struct glxiic_softc),
277 };
278 
279 static devclass_t glxiic_devclass;
280 
281 DRIVER_MODULE(glxiic, isab, glxiic_driver, glxiic_devclass, 0, 0);
282 DRIVER_MODULE(iicbus, glxiic, iicbus_driver, iicbus_devclass, 0, 0);
283 MODULE_DEPEND(glxiic, iicbus, 1, 1, 1);
284 
285 static void
286 glxiic_identify(driver_t *driver, device_t parent)
287 {
288 
289 	/* Prevent child from being added more than once. */
290 	if (device_find_child(parent, driver->name, -1) != NULL)
291 		return;
292 
293 	if (pci_get_devid(parent) == GLXIIC_CS5536_DEV_ID) {
294 		if (device_add_child(parent, driver->name, -1) == NULL)
295 			device_printf(parent, "Could not add glxiic child\n");
296 	}
297 }
298 
299 static int
300 glxiic_probe(device_t dev)
301 {
302 
303 	if (resource_disabled("glxiic", device_get_unit(dev)))
304 		return (ENXIO);
305 
306 	device_set_desc(dev, "AMD Geode CS5536 SMBus controller");
307 
308 	return (BUS_PROBE_DEFAULT);
309 }
310 
311 static int
312 glxiic_attach(device_t dev)
313 {
314 	struct glxiic_softc *sc;
315 	struct sysctl_ctx_list *ctx;
316 	struct sysctl_oid *tree;
317 	int error, irq, unit;
318 	uint32_t irq_map;
319 
320 	sc = device_get_softc(dev);
321 	sc->dev = dev;
322 	sc->state = GLXIIC_STATE_IDLE;
323 	error = 0;
324 
325 	GLXIIC_LOCK_INIT(sc);
326 	callout_init_mtx(&sc->callout, &sc->mtx, 0);
327 
328 	sc->smb_rid = PCIR_BAR(0);
329 	sc->smb_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &sc->smb_rid,
330 	    RF_ACTIVE);
331 	if (sc->smb_res == NULL) {
332 		device_printf(dev, "Could not allocate SMBus I/O port\n");
333 		error = ENXIO;
334 		goto out;
335 	}
336 
337 	sc->gpio_rid = PCIR_BAR(1);
338 	sc->gpio_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
339 	    &sc->gpio_rid, RF_SHAREABLE | RF_ACTIVE);
340 	if (sc->gpio_res == NULL) {
341 		device_printf(dev, "Could not allocate GPIO I/O port\n");
342 		error = ENXIO;
343 		goto out;
344 	}
345 
346 	/* Ensure the controller is not enabled by firmware. */
347 	glxiic_smb_disable(sc);
348 
349 	/* Read the existing IRQ map. */
350 	irq_map = rdmsr(GLXIIC_MSR_PIC_YSEL_HIGH);
351 	sc->old_irq = GLXIIC_MAP_TO_SMB_IRQ(irq_map);
352 
353 	unit = device_get_unit(dev);
354 	if (resource_int_value("glxiic", unit, "irq", &irq) == 0) {
355 		if (irq < 1 || irq > 15) {
356 			device_printf(dev, "Bad value %d for glxiic.%d.irq\n",
357 			    irq, unit);
358 			error = ENXIO;
359 			goto out;
360 		}
361 
362 		if (bootverbose)
363 			device_printf(dev, "Using irq %d set by hint\n", irq);
364 	} else if (sc->old_irq != 0) {
365 		if (bootverbose)
366 			device_printf(dev, "Using irq %d set by firmware\n",
367 			    irq);
368 		irq = sc->old_irq;
369 	} else {
370 		device_printf(dev, "No irq mapped by firmware");
371 		printf(" and no glxiic.%d.irq hint provided\n", unit);
372 		error = ENXIO;
373 		goto out;
374 	}
375 
376 	/* Map the SMBus interrupt to the requested legacy IRQ. */
377 	glxiic_smb_map_interrupt(irq);
378 
379 	sc->irq_rid = 0;
380 	sc->irq_res = bus_alloc_resource(dev, SYS_RES_IRQ, &sc->irq_rid,
381 	    irq, irq, 1, RF_SHAREABLE | RF_ACTIVE);
382 	if (sc->irq_res == NULL) {
383 		device_printf(dev, "Could not allocate IRQ %d\n", irq);
384 		error = ENXIO;
385 		goto out;
386 	}
387 
388 	error = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
389 	    NULL, glxiic_intr, sc, &(sc->irq_handler));
390 	if (error != 0) {
391 		device_printf(dev, "Could not setup IRQ handler\n");
392 		error = ENXIO;
393 		goto out;
394 	}
395 
396 	if ((sc->iicbus = device_add_child(dev, "iicbus", -1)) == NULL) {
397 		device_printf(dev, "Could not allocate iicbus instance\n");
398 		error = ENXIO;
399 		goto out;
400 	}
401 
402 	ctx = device_get_sysctl_ctx(dev);
403 	tree = device_get_sysctl_tree(dev);
404 
405 	sc->timeout = GLXIIC_DEFAULT_TIMEOUT;
406 	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
407 	    "timeout", CTLFLAG_RWTUN, &sc->timeout, 0,
408 	    "activity timeout in ms");
409 
410 	glxiic_gpio_enable(sc);
411 	glxiic_smb_enable(sc, IIC_FASTEST, 0);
412 
413 	/* Probe and attach the iicbus when interrupts are available. */
414 	config_intrhook_oneshot((ich_func_t)bus_generic_attach, dev);
415 	error = 0;
416 
417 out:
418 	if (error != 0) {
419 		callout_drain(&sc->callout);
420 
421 		if (sc->iicbus != NULL)
422 			device_delete_child(dev, sc->iicbus);
423 		if (sc->smb_res != NULL) {
424 			glxiic_smb_disable(sc);
425 			bus_release_resource(dev, SYS_RES_IOPORT, sc->smb_rid,
426 			    sc->smb_res);
427 		}
428 		if (sc->gpio_res != NULL) {
429 			glxiic_gpio_disable(sc);
430 			bus_release_resource(dev, SYS_RES_IOPORT, sc->gpio_rid,
431 			    sc->gpio_res);
432 		}
433 		if (sc->irq_handler != NULL)
434 			bus_teardown_intr(dev, sc->irq_res, sc->irq_handler);
435 		if (sc->irq_res != NULL)
436 			bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
437 			    sc->irq_res);
438 
439 		/* Restore the old SMBus interrupt mapping. */
440 		glxiic_smb_map_interrupt(sc->old_irq);
441 
442 		GLXIIC_LOCK_DESTROY(sc);
443 	}
444 
445 	return (error);
446 }
447 
448 static int
449 glxiic_detach(device_t dev)
450 {
451 	struct glxiic_softc *sc;
452 	int error;
453 
454 	sc = device_get_softc(dev);
455 
456 	error = bus_generic_detach(dev);
457 	if (error != 0)
458 		goto out;
459 	if (sc->iicbus != NULL)
460 		error = device_delete_child(dev, sc->iicbus);
461 
462 out:
463 	callout_drain(&sc->callout);
464 
465 	if (sc->smb_res != NULL) {
466 		glxiic_smb_disable(sc);
467 		bus_release_resource(dev, SYS_RES_IOPORT, sc->smb_rid,
468 		    sc->smb_res);
469 	}
470 	if (sc->gpio_res != NULL) {
471 		glxiic_gpio_disable(sc);
472 		bus_release_resource(dev, SYS_RES_IOPORT, sc->gpio_rid,
473 		    sc->gpio_res);
474 	}
475 	if (sc->irq_handler != NULL)
476 		bus_teardown_intr(dev, sc->irq_res, sc->irq_handler);
477 	if (sc->irq_res != NULL)
478 		bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
479 		    sc->irq_res);
480 
481 	/* Restore the old SMBus interrupt mapping. */
482 	glxiic_smb_map_interrupt(sc->old_irq);
483 
484 	GLXIIC_LOCK_DESTROY(sc);
485 
486 	return (error);
487 }
488 
489 static uint8_t
490 glxiic_read_status_locked(struct glxiic_softc *sc)
491 {
492 	uint8_t status;
493 
494 	GLXIIC_ASSERT_LOCKED(sc);
495 
496 	status = bus_read_1(sc->smb_res, GLXIIC_SMB_STS);
497 
498 	/* Clear all status flags except SDAST and STASTR after reading. */
499 	bus_write_1(sc->smb_res, GLXIIC_SMB_STS, (GLXIIC_SMB_STS_SLVSTP_BIT |
500 		GLXIIC_SMB_STS_BER_BIT | GLXIIC_SMB_STS_NEGACK_BIT |
501 		GLXIIC_SMB_STS_NMATCH_BIT));
502 
503 	return (status);
504 }
505 
506 static void
507 glxiic_stop_locked(struct glxiic_softc *sc)
508 {
509 	uint8_t status, ctrl1;
510 
511 	GLXIIC_ASSERT_LOCKED(sc);
512 
513 	status = glxiic_read_status_locked(sc);
514 
515 	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
516 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
517 	    ctrl1 | GLXIIC_SMB_CTRL1_STOP_BIT);
518 
519 	/*
520 	 * Perform a dummy read of SDA in master receive mode to clear
521 	 * SDAST if set.
522 	 */
523 	if ((status & GLXIIC_SMB_STS_XMIT_BIT) == 0 &&
524 	    (status & GLXIIC_SMB_STS_SDAST_BIT) != 0)
525 	 	bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
526 
527 	/* Check stall after start bit and clear if needed */
528 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
529 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
530 		    GLXIIC_SMB_STS_STASTR_BIT);
531 	}
532 }
533 
534 static void
535 glxiic_timeout(void *arg)
536 {
537 	struct glxiic_softc *sc;
538 	uint8_t error;
539 
540 	sc = (struct glxiic_softc *)arg;
541 
542 	GLXIIC_DEBUG_LOG("timeout in state %d", sc->state);
543 
544 	if (glxiic_state_table[sc->state].master) {
545 		sc->error = IIC_ETIMEOUT;
546 		GLXIIC_WAKEUP(sc);
547 	} else {
548 		error = IIC_ETIMEOUT;
549 		iicbus_intr(sc->iicbus, INTR_ERROR, &error);
550 	}
551 
552 	glxiic_smb_disable(sc);
553 	glxiic_smb_enable(sc, IIC_UNKNOWN, sc->addr);
554 	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
555 }
556 
557 static void
558 glxiic_start_timeout_locked(struct glxiic_softc *sc)
559 {
560 
561 	GLXIIC_ASSERT_LOCKED(sc);
562 
563 	callout_reset_sbt(&sc->callout, SBT_1MS * sc->timeout, 0,
564 	    glxiic_timeout, sc, 0);
565 }
566 
567 static void
568 glxiic_set_state_locked(struct glxiic_softc *sc, glxiic_state_t state)
569 {
570 
571 	GLXIIC_ASSERT_LOCKED(sc);
572 
573 	if (state == GLXIIC_STATE_IDLE)
574 		callout_stop(&sc->callout);
575 	else if (sc->timeout > 0)
576 		glxiic_start_timeout_locked(sc);
577 
578 	sc->state = state;
579 }
580 
581 static int
582 glxiic_handle_slave_match_locked(struct glxiic_softc *sc, uint8_t status)
583 {
584 	uint8_t ctrl_sts, addr;
585 
586 	GLXIIC_ASSERT_LOCKED(sc);
587 
588 	ctrl_sts = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL_STS);
589 
590 	if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_MATCH_BIT) != 0) {
591 		if ((status & GLXIIC_SMB_STS_XMIT_BIT) != 0) {
592 			addr = sc->addr | LSB;
593 			glxiic_set_state_locked(sc,
594 			    GLXIIC_STATE_SLAVE_TX);
595 		} else {
596 			addr = sc->addr & ~LSB;
597 			glxiic_set_state_locked(sc,
598 			    GLXIIC_STATE_SLAVE_RX);
599 		}
600 		iicbus_intr(sc->iicbus, INTR_START, &addr);
601 	} else if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_GCMTCH_BIT) != 0) {
602 		addr = 0;
603 		glxiic_set_state_locked(sc, GLXIIC_STATE_SLAVE_RX);
604 		iicbus_intr(sc->iicbus, INTR_GENERAL, &addr);
605 	} else {
606 		GLXIIC_DEBUG_LOG("unknown slave match");
607 		return (IIC_ESTATUS);
608 	}
609 
610 	return (IIC_NOERR);
611 }
612 
613 static int
614 glxiic_state_idle_callback(struct glxiic_softc *sc, uint8_t status)
615 {
616 
617 	GLXIIC_ASSERT_LOCKED(sc);
618 
619 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
620 		GLXIIC_DEBUG_LOG("bus error in idle");
621 		return (IIC_EBUSERR);
622 	}
623 
624 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
625 		return (glxiic_handle_slave_match_locked(sc, status));
626 	}
627 
628 	return (IIC_NOERR);
629 }
630 
631 static int
632 glxiic_state_slave_tx_callback(struct glxiic_softc *sc, uint8_t status)
633 {
634 	uint8_t data;
635 
636 	GLXIIC_ASSERT_LOCKED(sc);
637 
638 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
639 		GLXIIC_DEBUG_LOG("bus error in slave tx");
640 		return (IIC_EBUSERR);
641 	}
642 
643 	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
644 		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
645 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
646 		return (IIC_NOERR);
647 	}
648 
649 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
650 		iicbus_intr(sc->iicbus, INTR_NOACK, NULL);
651 		return (IIC_NOERR);
652 	}
653 
654 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
655 		/* Handle repeated start in slave mode. */
656 		return (glxiic_handle_slave_match_locked(sc, status));
657 	}
658 
659 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
660 		GLXIIC_DEBUG_LOG("not awaiting data in slave tx");
661 		return (IIC_ESTATUS);
662 	}
663 
664 	iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data);
665 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, data);
666 
667 	glxiic_start_timeout_locked(sc);
668 
669 	return (IIC_NOERR);
670 }
671 
672 static int
673 glxiic_state_slave_rx_callback(struct glxiic_softc *sc, uint8_t status)
674 {
675 	uint8_t data;
676 
677 	GLXIIC_ASSERT_LOCKED(sc);
678 
679 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
680 		GLXIIC_DEBUG_LOG("bus error in slave rx");
681 		return (IIC_EBUSERR);
682 	}
683 
684 	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
685 		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
686 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
687 		return (IIC_NOERR);
688 	}
689 
690 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
691 		/* Handle repeated start in slave mode. */
692 		return (glxiic_handle_slave_match_locked(sc, status));
693 	}
694 
695 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
696 		GLXIIC_DEBUG_LOG("no pending data in slave rx");
697 		return (IIC_ESTATUS);
698 	}
699 
700 	data = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
701 	iicbus_intr(sc->iicbus, INTR_RECEIVE, &data);
702 
703 	glxiic_start_timeout_locked(sc);
704 
705 	return (IIC_NOERR);
706 }
707 
708 static int
709 glxiic_state_master_addr_callback(struct glxiic_softc *sc, uint8_t status)
710 {
711 	uint8_t slave;
712 	uint8_t ctrl1;
713 
714 	GLXIIC_ASSERT_LOCKED(sc);
715 
716 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
717 		GLXIIC_DEBUG_LOG("bus error after master start");
718 		return (IIC_EBUSERR);
719 	}
720 
721 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
722 		GLXIIC_DEBUG_LOG("not bus master after master start");
723 		return (IIC_ESTATUS);
724 	}
725 
726 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
727 		GLXIIC_DEBUG_LOG("not awaiting address in master addr");
728 		return (IIC_ESTATUS);
729 	}
730 
731 	if ((sc->msg->flags & IIC_M_RD) != 0) {
732 		slave = sc->msg->slave | LSB;
733 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_RX);
734 	} else {
735 		slave = sc->msg->slave & ~LSB;
736 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_TX);
737 	}
738 
739 	sc->data = sc->msg->buf;
740 	sc->ndata = sc->msg->len;
741 
742 	/* Handle address-only transfer. */
743 	if (sc->ndata == 0)
744 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
745 
746 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, slave);
747 
748 	if ((sc->msg->flags & IIC_M_RD) != 0 && sc->ndata == 1) {
749 		/* Last byte from slave, set NACK. */
750 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
751 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
752 		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
753 	}
754 
755 	return (IIC_NOERR);
756 }
757 
758 static int
759 glxiic_state_master_tx_callback(struct glxiic_softc *sc, uint8_t status)
760 {
761 
762 	GLXIIC_ASSERT_LOCKED(sc);
763 
764 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
765 		GLXIIC_DEBUG_LOG("bus error in master tx");
766 		return (IIC_EBUSERR);
767 	}
768 
769 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
770 		GLXIIC_DEBUG_LOG("not bus master in master tx");
771 		return (IIC_ESTATUS);
772 	}
773 
774 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
775 		GLXIIC_DEBUG_LOG("slave nack in master tx");
776 		return (IIC_ENOACK);
777 	}
778 
779 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
780 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
781 		    GLXIIC_SMB_STS_STASTR_BIT);
782 	}
783 
784 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
785 		GLXIIC_DEBUG_LOG("not awaiting data in master tx");
786 		return (IIC_ESTATUS);
787 	}
788 
789 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, *sc->data++);
790 	if (--sc->ndata == 0)
791 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
792 	else
793 		glxiic_start_timeout_locked(sc);
794 
795 	return (IIC_NOERR);
796 }
797 
798 static int
799 glxiic_state_master_rx_callback(struct glxiic_softc *sc, uint8_t status)
800 {
801 	uint8_t ctrl1;
802 
803 	GLXIIC_ASSERT_LOCKED(sc);
804 
805 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
806 		GLXIIC_DEBUG_LOG("bus error in master rx");
807 		return (IIC_EBUSERR);
808 	}
809 
810 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
811 		GLXIIC_DEBUG_LOG("not bus master in master rx");
812 		return (IIC_ESTATUS);
813 	}
814 
815 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
816 		GLXIIC_DEBUG_LOG("slave nack in rx");
817 		return (IIC_ENOACK);
818 	}
819 
820 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
821 		/* Bus is stalled, clear and wait for data. */
822 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
823 		    GLXIIC_SMB_STS_STASTR_BIT);
824 		return (IIC_NOERR);
825 	}
826 
827 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
828 		GLXIIC_DEBUG_LOG("no pending data in master rx");
829 		return (IIC_ESTATUS);
830 	}
831 
832 	*sc->data++ = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
833 	if (--sc->ndata == 0) {
834 		/* Proceed with stop on reading last byte. */
835 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
836 		return (glxiic_state_table[sc->state].callback(sc, status));
837 	}
838 
839 	if (sc->ndata == 1) {
840 		/* Last byte from slave, set NACK. */
841 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
842 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
843 		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
844 	}
845 
846 	glxiic_start_timeout_locked(sc);
847 
848 	return (IIC_NOERR);
849 }
850 
851 static int
852 glxiic_state_master_stop_callback(struct glxiic_softc *sc, uint8_t status)
853 {
854 	uint8_t ctrl1;
855 
856 	GLXIIC_ASSERT_LOCKED(sc);
857 
858 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
859 		GLXIIC_DEBUG_LOG("bus error in master stop");
860 		return (IIC_EBUSERR);
861 	}
862 
863 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
864 		GLXIIC_DEBUG_LOG("not bus master in master stop");
865 		return (IIC_ESTATUS);
866 	}
867 
868 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
869 		GLXIIC_DEBUG_LOG("slave nack in master stop");
870 		return (IIC_ENOACK);
871 	}
872 
873 	if (--sc->nmsgs > 0) {
874 		/* Start transfer of next message. */
875 		if ((sc->msg->flags & IIC_M_NOSTOP) == 0) {
876 			glxiic_stop_locked(sc);
877 		}
878 
879 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
880 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
881 		    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
882 
883 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
884 		sc->msg++;
885 	} else {
886 		/* Last message. */
887 		glxiic_stop_locked(sc);
888 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
889 		sc->error = IIC_NOERR;
890 		GLXIIC_WAKEUP(sc);
891 	}
892 
893 	return (IIC_NOERR);
894 }
895 
896 static void
897 glxiic_intr(void *arg)
898 {
899 	struct glxiic_softc *sc;
900 	int error;
901 	uint8_t status, data;
902 
903 	sc = (struct glxiic_softc *)arg;
904 
905 	GLXIIC_LOCK(sc);
906 
907 	status = glxiic_read_status_locked(sc);
908 
909 	/* Check if this interrupt originated from the SMBus. */
910 	if ((status &
911 		~(GLXIIC_SMB_STS_MASTER_BIT | GLXIIC_SMB_STS_XMIT_BIT)) != 0) {
912 
913 		error = glxiic_state_table[sc->state].callback(sc, status);
914 
915 		if (error != IIC_NOERR) {
916 			if (glxiic_state_table[sc->state].master) {
917 				glxiic_stop_locked(sc);
918 				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
919 				sc->error = error;
920 				GLXIIC_WAKEUP(sc);
921 			} else {
922 				data = error & 0xff;
923 				iicbus_intr(sc->iicbus, INTR_ERROR, &data);
924 				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
925 			}
926 		}
927 	}
928 
929 	GLXIIC_UNLOCK(sc);
930 }
931 
932 static int
933 glxiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
934 {
935 	struct glxiic_softc *sc;
936 
937 	sc = device_get_softc(dev);
938 
939 	GLXIIC_LOCK(sc);
940 
941 	if (oldaddr != NULL)
942 		*oldaddr = sc->addr;
943 	sc->addr = addr;
944 
945 	/* A disable/enable cycle resets the controller. */
946 	glxiic_smb_disable(sc);
947 	glxiic_smb_enable(sc, speed, addr);
948 
949 	if (glxiic_state_table[sc->state].master) {
950 		sc->error = IIC_ESTATUS;
951 		GLXIIC_WAKEUP(sc);
952 	}
953 	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
954 
955 	GLXIIC_UNLOCK(sc);
956 
957 	return (IIC_NOERR);
958 }
959 
960 static int
961 glxiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
962 {
963 	struct glxiic_softc *sc;
964 	int error;
965 	uint8_t ctrl1;
966 
967 	sc = device_get_softc(dev);
968 
969 	GLXIIC_LOCK(sc);
970 
971 	if (sc->state != GLXIIC_STATE_IDLE) {
972 		error = IIC_EBUSBSY;
973 		goto out;
974 	}
975 
976 	sc->msg = msgs;
977 	sc->nmsgs = nmsgs;
978 	glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
979 
980 	/* Set start bit and let glxiic_intr() handle the transfer. */
981 	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
982 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
983 	    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
984 
985 	GLXIIC_SLEEP(sc);
986 	error = sc->error;
987 out:
988 	GLXIIC_UNLOCK(sc);
989 
990 	return (error);
991 }
992 
993 static void
994 glxiic_smb_map_interrupt(int irq)
995 {
996 	uint32_t irq_map;
997 	int old_irq;
998 
999 	/* Protect the read-modify-write operation. */
1000 	critical_enter();
1001 
1002 	irq_map = rdmsr(GLXIIC_MSR_PIC_YSEL_HIGH);
1003 	old_irq = GLXIIC_MAP_TO_SMB_IRQ(irq_map);
1004 
1005 	if (irq != old_irq) {
1006 		irq_map &= ~GLXIIC_SMB_IRQ_TO_MAP(old_irq);
1007 		irq_map |= GLXIIC_SMB_IRQ_TO_MAP(irq);
1008 		wrmsr(GLXIIC_MSR_PIC_YSEL_HIGH, irq_map);
1009 	}
1010 
1011 	critical_exit();
1012 }
1013 
1014 static void
1015 glxiic_gpio_enable(struct glxiic_softc *sc)
1016 {
1017 
1018 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1019 	    GLXIIC_GPIO_14_15_ENABLE);
1020 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1021 	    GLXIIC_GPIO_14_15_ENABLE);
1022 }
1023 
1024 static void
1025 glxiic_gpio_disable(struct glxiic_softc *sc)
1026 {
1027 
1028 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1029 	    GLXIIC_GPIO_14_15_DISABLE);
1030 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1031 	    GLXIIC_GPIO_14_15_DISABLE);
1032 }
1033 
1034 static void
1035 glxiic_smb_enable(struct glxiic_softc *sc, uint8_t speed, uint8_t addr)
1036 {
1037 	uint8_t ctrl1;
1038 
1039 	ctrl1 = 0;
1040 
1041 	switch (speed) {
1042 	case IIC_SLOW:
1043 		sc->sclfrq = GLXIIC_SLOW;
1044 		break;
1045 	case IIC_FAST:
1046 		sc->sclfrq = GLXIIC_FAST;
1047 		break;
1048 	case IIC_FASTEST:
1049 		sc->sclfrq = GLXIIC_FASTEST;
1050 		break;
1051 	case IIC_UNKNOWN:
1052 	default:
1053 		/* Reuse last frequency. */
1054 		break;
1055 	}
1056 
1057 	/* Set bus speed and enable controller. */
1058 	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1059 	    GLXIIC_SCLFRQ(sc->sclfrq) | GLXIIC_SMB_CTRL2_EN_BIT);
1060 
1061 	if (addr != 0) {
1062 		/* Enable new match and global call match interrupts. */
1063 		ctrl1 |= GLXIIC_SMB_CTRL1_NMINTE_BIT |
1064 			GLXIIC_SMB_CTRL1_GCMEN_BIT;
1065 		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR,
1066 		    GLXIIC_SMB_ADDR_SAEN_BIT | GLXIIC_SMBADDR(addr));
1067 	} else {
1068 		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR, 0);
1069 	}
1070 
1071 	/* Enable stall after start and interrupt. */
1072 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
1073 	    ctrl1 | GLXIIC_SMB_CTRL1_STASTRE_BIT | GLXIIC_SMB_CTRL1_INTEN_BIT);
1074 }
1075 
1076 static void
1077 glxiic_smb_disable(struct glxiic_softc *sc)
1078 {
1079 	uint16_t sclfrq;
1080 
1081 	sclfrq = bus_read_2(sc->smb_res, GLXIIC_SMB_CTRL2);
1082 	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1083 	    sclfrq & ~GLXIIC_SMB_CTRL2_EN_BIT);
1084 }
1085